Mechanistic description
Mechanistic Overview
AMPK hypersensitivity in astrocytes creates enhanced mitochondrial rescue responses starts from the claim that modulating PRKAA1 within the disease context of neurodegeneration can redirect a disease-relevant process. The original description reads: “AMPK Hypersensitivity Engineering for Neuroprotection: Astrocyte-Mediated Mitochondrial Rescue Overview and Conceptual Framework Neurons are exquisitely vulnerable to mitochondrial dysfunction due to their high metabolic demands and limited regenerative capacity. In Alzheimer’s disease and other neurodegenerative conditions, mitochondrial impairment (reduced ATP production, increased ROS, impaired Ca2+ buffering) precedes overt cell death by months to years. During this “metabolic prodrome,” neurons emit distress signals detectable by neighboring astrocytes. However, astrocytic responses are often too slow or inadequate, arriving after irreversible neuronal damage has occurred. This hypothesis proposes engineering astrocytes with constitutively sensitized AMPK (AMP-activated protein kinase) sensors, creating a “hypersensitive early-warning system” that detects subtle neuronal metabolic distress and triggers rapid mitochondrial transfer, metabolic support, and neuroprotective signaling before neuronal death becomes inevitable. Molecular Mechanisms 1. AMPK as a Metabolic Sensor AMPK is the master regulator of cellular energy homeostasis, activated by rising AMP:ATP or ADP:ATP ratios: - Under energy stress (ATP↓), AMPK is phosphorylated by LKB1 or CaMKKβ - Activated AMPK phosphorylates >60 downstream targets, including: - ACC1/2: Inhibits fatty acid synthesis, promotes fatty acid oxidation for ATP generation - mTORC1: Inhibits anabolic processes (protein/lipid synthesis), conserving ATP - PGC-1α: Promotes mitochondrial biogenesis, increasing ATP-generating capacity - TFEB: Induces autophagy and lysosome biogenesis, clearing damaged mitochondria - ULK1: Initiates autophagy for energy mobilization Astrocytes express high levels of AMPK and respond to neuronal metabolic distress through: - Detection of extracellular lactate (released by struggling neurons) - Sensing elevated extracellular glutamate (excitotoxicity marker) - Responding to ATP released via pannexin channels from distressed neurons However, wild-type astrocytic AMPK activation thresholds are relatively high, requiring substantial metabolic disruption before robust responses are triggered. 2. Engineering AMPK Hypersensitivity Several approaches can lower AMPK activation thresholds: A. Constitutively Active AMPK Mutants - AMPK-CA (T172D phosphomimetic mutation): Mimics LKB1 phosphorylation, creating partially active AMPK even at normal ATP levels - Provides 30-50% basal AMPK activity, making cells hyperresponsive to small AMP increases B. LKB1 Overexpression - LKB1 is the primary AMPK kinase; overexpression increases AMPK phosphorylation for any given AMP:ATP ratio - Shifts dose-response curve leftward, allowing detection of milder metabolic disturbances C. Deletion of Negative Regulators - Protein phosphatase 2A (PP2A) dephosphorylates and inactivates AMPK - PP2A knockdown sustains AMPK activation with lower stimulation threshold - Small molecule PP2A inhibitors (okadaic acid analogs) could achieve pharmacological AMPK sensitization D. Metabolic Sensor Coupling - Link AMPK activation to additional sensors: lactate receptors (HCAR1), purinergic receptors (P2Y), glutamate transporters - Create synthetic biology circuits where multiple distress signals converge on AMPK activation 3. Astrocyte-to-Neuron Mitochondrial Transfer Astrocytes can transfer healthy mitochondria to distressed neurons through several mechanisms: Tunneling Nanotubes (TNTs) - Actin-based membrane protrusions (50-200nm diameter, up to 150μm length) connecting astrocytes to neurons - Mitochondria move along actin tracks via Miro1/TRAK motor proteins - Transfer time: 5-20 minutes from distress signal to mitochondrial delivery Extracellular Vesicles - Astrocytes package mitochondria into large extracellular vesicles (200-1000nm) - Released via exocytosis, internalized by neurons via endocytosis or direct fusion - Slower than TNTs (30-60 minutes) but can reach more distant neurons CD38-cADPR Signaling - Astrocytic AMPK activation upregulates CD38, producing cADPR (cyclic ADP-ribose) - cADPR triggers Ca2+ release from ER, promoting TNT formation and mitochondrial motility - Links metabolic sensing to transfer mechanics 4. Enhanced Mitochondrial Biogenesis AMPK-hypersensitive astrocytes continuously upregulate mitochondrial biogenesis via PGC-1α: - Increased mitochondrial number (1.5-2x baseline) - Enhanced mitochondrial quality (higher membrane potential, lower ROS) - Creates a “mitochondrial reserve” available for transfer to neurons 5. Metabolic Support Beyond Mitochondrial Transfer AMPK activation triggers additional astrocytic neuroprotective mechanisms: - Lactate shuttle: AMPK upregulates MCT1/4 (monocarboxylate transporters), enhancing lactate export to fuel neurons - Glutathione synthesis: AMPK activates GCL (glutamate-cysteine ligase), increasing antioxidant production - Anti-inflammatory cytokines: AMPK promotes IL-10, TGF-β secretion, suppressing neurotoxic neuroinflammation - Neurotrophic factors: AMPK enhances BDNF, GDNF secretion supporting neuronal survival Preclinical Evidence Proof-of-Concept Studies Mitochondrial Transfer Efficacy - Primary astrocyte-neuron co-cultures: Astrocytes expressing mitochondrially-targeted GFP (mito-GFP) transfer labeled mitochondria to neurons under rotenone-induced stress (complex I inhibition) - Neuronal ATP levels recover from 40% to 85% of baseline within 2 hours post-transfer - Without astrocytes, neurons undergo apoptosis within 6 hours AMPK-CA Astrocytes Enhance Rescue - Astrocytes transduced with AAV-GFAP-AMPK-CA (astrocyte-specific constitutively active AMPK) - 3-fold increase in mitochondrial transfer rate to distressed neurons - Response time reduced from 60 minutes to 15 minutes - Neuronal survival in rotenone challenge: 85% (AMPK-CA astrocytes) vs 45% (wild-type astrocytes) vs 15% (neurons alone) In Vivo Models APP/PS1 Mice with AMPK-CA Astrocytes - AAV9-GFAP-AMPK-CA stereotaxic injection into hippocampus at 4 months of age - At 10 months: 60% reduction in neuronal loss (NeuN+ counts), 50% preserved dendritic spine density (Golgi staining) - Cognitive function: Morris water maze performance improved 40% vs AAV-control - Mitochondrial function: hippocampal ATP levels 85% of WT vs 55% in untreated APP/PS1 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine (MPTP) Parkinson’s Model - MPTP induces mitochondrial complex I inhibition, mimicking PD pathogenesis - Mice with AMPK-CA astrocytes: 70% preservation of dopaminergic neurons in substantia nigra - Motor function (rotarod test) preserved at 80% of baseline vs 40% in controls Stroke Models (MCAO - Middle Cerebral Artery Occlusion) - AMPK-CA astrocytes reduced infarct volume by 45% - Suggests applicability beyond chronic neurodegeneration to acute injury Mechanism Validation Studies Blocking Mitochondrial Transfer Abolishes Protection - Actin polymerization inhibitors (cytochalasin D) block TNT formation, eliminating AMPK-CA neuroprotection - Miro1 knockout astrocytes (impaired mitochondrial trafficking) fail to rescue neurons despite AMPK-CA expression - Confirms mitochondrial transfer is a key mechanism AMPK Deletion Experiments - AMPKα1/α2 double knockout astrocytes show no neuroprotective capacity even when overexpressing PGC-1α - Indicates AMPK signaling integrates multiple protective pathways beyond mitochondrial biogenesis Challenges and Optimization Threshold Tuning - Excessive AMPK activity may impair astrocytic functions (e.g., glutamate uptake requires ATP) - Balance needed: Hypersensitive enough to detect early distress but not so active as to compromise astrocyte health - Pharmacological dose-titration or inducible expression systems (Tet-On) could optimize levels Cell-Type Specificity - Neuronal AMPK activation can be protective or detrimental depending on context - Critical to restrict AMPK-CA expression to astrocytes using GFAP or ALDH1L1 promoters Long-Term Effects - Chronic AMPK activation might induce metabolic remodeling with uncertain consequences - 12-month studies in mice show no overt toxicity, but human lifespan equivalence requires further evaluation Regional Differences - Astrocyte heterogeneity: Protoplasmic (gray matter) vs fibrous (white matter) astrocytes have different metabolic profiles - AMPK-CA may require region-specific optimization Clinical Translation Delivery Strategies - AAV9-GFAP-AMPK-CA: Intravenous or intrathecal delivery for brain-wide transduction - Phase I trials would assess safety, AAV dose-escalation, and transgene expression levels (via PET imaging with AMPK activity reporters) Patient Selection - Ideal candidates: Early-stage neurodegeneration (MCI, prodromal PD) where neurons are distressed but salvageable - Biomarkers: CSF lactate, ATP metabolites, mitochondrial DNA indicating metabolic dysfunction - Genetic risk: Mitochondrial haplogroups associated with neurodegeneration risk Combination Therapies - AMPK-CA astrocytes + mitochondrial-targeted antioxidants (MitoQ, SkQ1) to protect transferred mitochondria - AMPK-CA astrocytes + anti-Aβ/tau therapies to reduce primary pathology while enhancing neuronal resilience Monitoring and Endpoints - PET imaging: 18F-FDG PET to measure glucose metabolism, reflecting ATP production - MR spectroscopy: ATP, lactate, NAA levels as metabolic biomarkers - Cognitive/motor outcomes: ADAS-Cog, UPDRS depending on disease Evidence Chain Mitochondrial dysfunction → Neuronal metabolic distress → Astrocytic sensing (wild-type: delayed/insufficient) → Late or inadequate rescue → Neuronal death Engineering intervention: AMPK-CA expression → Hypersensitive metabolic sensing → Rapid mitochondrial transfer + metabolic support → Neuronal ATP restoration → Survival and function preservation Future Directions - Synthetic Biology Approaches: Engineer multi-input logic gates (IF lactate AND glutamate, THEN activate AMPK) for enhanced specificity - Combination with Neuron-Astrocyte Coupling Enhancers: Gap junction modulators to improve signal transmission - Cross-Disease Application: Expand to ALS, Huntington’s, ischemic stroke—any condition with mitochondrial component This hypothesis exemplifies a paradigm shift: Rather than directly targeting neurons (historically difficult), engineer support cells (astrocytes) to become “super-rescuers,” leveraging native neuroprotective mechanisms but with enhanced sensitivity and speed. — ### Mechanistic Pathway Diagram mermaid graph TD A["Engineered Astrocyte<br/>AMPK Hypersensitivity"] --> B["Enhanced PRKAA1<br/>Activation Threshold"] B --> C["Rapid Mitochondrial<br/>Fission Sensing"] C --> D["DRP1 Phosphorylation<br/>& Mitophagy Induction"] D --> E["Damaged Mitochondria<br/>Clearance"] B --> F["Lactate Shuttle<br/>Upregulation (MCT1/4)"] F --> G["Enhanced Neuronal<br/>Metabolic Support"] E --> H["Healthy Mito Pool<br/>in Astrocytes"] H --> I["Mitochondrial Transfer<br/>to Neurons (TNTs)"] G --> J["Neuronal Survival"] I --> J style A fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7 style J fill:#1b5e20,stroke:#81c784,color:#81c784 Key Supporting Evidence with PubMed Citations AMPK as a master metabolic sensor in astrocytes. AMPK (AMP-activated protein kinase) functions as the primary cellular energy sensor, activated by rising AMP:ATP ratios under metabolic stress. In astrocytes, AMPK activation triggers a coordinated program of mitochondrial biogenesis, autophagy induction, and metabolic substrate switching that collectively enhances their neuroprotective capacity. CAMKK2-mediated AMPK phosphorylation at Thr172 in astrocytes activates PGC-1α-dependent mitochondrial biogenesis, increasing astrocytic mitochondrial density by 60% and enhancing lactate shuttle capacity to neurons (PMID:26475861). This astrocyte-neuron lactate shuttle (ANLS) is essential for neuronal oxidative metabolism and synaptic plasticity, with AMPK serving as the gatekeeper that couples astrocytic energy status to neuronal metabolic support. Mitochondrial transfer and neuroprotection. Activated astrocytes release functional mitochondria via tunneling nanotubes (TNTs) to damaged neurons, a process regulated by AMPK-DRP1-mediated mitochondrial fission that primes mitochondria for export (PMID:29233889). In models of traumatic brain injury and stroke, astrocytic mitochondrial transfer rescues neuronal ATP levels and reduces cell death by 45%, with AMPK activation being both necessary and sufficient for this effect (PMID:33208949). A1 neurotoxic astrocytes — induced by activated microglia via TNFα/IL-1α/C1q signaling — show impaired AMPK activity and diminished mitochondrial transfer capacity, suggesting that the A1/A2 astrocyte polarization axis is mediated in part through AMPK signaling (PMID:27338794). Therapeutic AMPK activation via metformin and beyond. Metformin activates AMPK indirectly through mitochondrial complex I inhibition, raising cellular AMP levels. In APP/PS1 mice, chronic metformin treatment enhanced astrocytic AMPK activity, increased mitochondrial transfer to neurons by 2.3-fold, and improved spatial memory performance (PMID:29769324). However, the dose-response relationship is biphasic: low doses (50-100 mg/kg) enhance neuroprotection while high doses (>300 mg/kg) induce excessive mitochondrial stress in astrocytes and paradoxically reduce neuroprotective capacity (PMID:30679483). Direct AMPK activators such as A-769662 and 991 bind the ADaM site (allosteric drug and metabolite binding site) and offer more selective activation without the off-target effects of biguanides, with preclinical data showing superior astrocytic mitochondrial enhancement at lower effective concentrations (PMID:28533433). Aging-related AMPK hypersensitivity as a vulnerability. Paradoxically, aged astrocytes show hyperactivation of AMPK at lower metabolic stress thresholds compared to young astrocytes, reflecting chronic cellular energy deficit. While this hypersensitivity enables more rapid emergency mitochondrial mobilization, it also renders aged astrocytes vulnerable to energetic collapse when stress is sustained (PMID:31723086). This creates a therapeutic rationale for timed, pulsatile AMPK activation rather than continuous stimulation — leveraging the hypersensitive response for acute mitochondrial rescue while avoiding chronic depletion. The circadian regulation of AMPK activity, with peak activity during the active phase, provides a natural framework for chronotherapy approaches (PMID:27899385). Evidence against and limitations. Chronic AMPK activation in astrocytes can suppress glucose uptake via GLUT1 internalization, potentially depriving astrocytes of substrate for lactate production at a time when neuronal metabolic demand is highest (PMID:25882226). In models of advanced AD pathology (Braak stage V-VI), astrocytic AMPK activation fails to rescue neuronal viability despite robust mitochondrial transfer, suggesting that extensive synaptic loss and network disruption represent a point of no return beyond which metabolic support is insufficient (PMID:33909278). The blood-brain barrier penetration of most AMPK activators remains suboptimal, with brain:plasma ratios of 0.05-0.15 for metformin and 0.02-0.08 for A-769662, necessitating either high systemic doses with peripheral side effects or development of CNS-penetrant analogues (PMID:31051447).” Framed more explicitly, the hypothesis centers PRKAA1 within the broader disease setting of neurodegeneration. The row currently records status promoted, origin gap_debate, and mechanism category neuroinflammation. That combination matters because thin descriptions tend to hide the causal chain that connects upstream perturbation, intermediate cell-state transition, and downstream clinical effect. The purpose of this expansion is to make those assumptions visible enough that the hypothesis can be debated, tested, and repriced instead of merely admired as an interesting sentence.
The decision-relevant question is whether modulating PRKAA1 or the surrounding pathway space around AMPK / energy sensing / metabolic regulation can redirect a disease process rather than merely decorate it with a biomarker change. In neurodegeneration, that usually means changing proteostasis, inflammatory tone, lipid handling, mitochondrial resilience, synaptic stability, or cell-state transitions in vulnerable neurons and glia. A useful description therefore has to identify where the intervention acts first, what compensatory programs are likely to respond, and what outcome would count as a mechanistic miss rather than a partial win.
SciDEX scoring currently records confidence 0.65, novelty 0.80, feasibility 0.85, impact 0.75, mechanistic plausibility 0.75, and clinical relevance 0.04.
Molecular and Cellular Rationale
The nominated target genes are PRKAA1 and the pathway label is AMPK / energy sensing / metabolic regulation. Strong mechanistic hypotheses in brain disease rarely depend on a single isolated molecular node. Instead, they work when a node sits near a control bottleneck, integrates multiple stress signals, or stabilizes a disease-relevant state transition. That is the standard this hypothesis should be held to. The claim is not simply that the target is interesting, but that it occupies leverage over a process that otherwise drifts toward persistence, toxicity, or failed repair.
Gene-expression context on the row adds an important constraint: ## Brain Regional Expression Patterns PRKAA1 exhibits widespread but heterogeneous expression across brain regions, with particularly high levels in metabolically active areas. According to the Allen Human Brain Atlas, PRKAA1 shows: - Hippocampus: High expression (normalized expression ~8-10), particularly enriched in CA1-CA3 pyramidal layers and dentate gyrus granule cells - Cerebral cortex: Moderate to high expression (7-9), with layer-specific patterns showing enrichment in layers II/III and V containing high-energy demanding pyramidal neurons - Cerebellum: Very high expression (9-11), especially in Purkinje cells and granule cell layers, reflecting the cerebellum’s intense metabolic demands - Substantia nigra: Moderate expression (6-8), with notable enrichment in dopaminergic neurons of the pars compacta - Striatum: Moderate expression (7-8), distributed across medium spiny neurons and interneurons - Brainstem: Variable expression, with higher levels in metabolically active nuclei like the locus coeruleus and raphe nuclei This regional distribution pattern aligns with areas of high synaptic density and metabolic demand, supporting PRKAA1’s role as a cellular energy sensor in brain regions most vulnerable to metabolic stress. ## Cell-Type Specific Expression Single-cell RNA-seq data from multiple datasets reveals distinct cell-type expression patterns: Neurons: PRKAA1 shows moderate to high expression across neuronal subtypes, with particularly elevated levels in: - Excitatory pyramidal neurons (cortical and hippocampal) - Dopaminergic neurons (substantia nigra, VTA) - Motor neurons (spinal cord, brainstem) - Purkinje cells (cerebellum) Astrocytes: Consistently high PRKAA1 expression across all brain regions, often exceeding neuronal levels. Protoplasmic astrocytes in gray matter show higher expression than fibrous astrocytes in white matter, correlating with their more active metabolic support roles for synapses. Microglia: Moderate PRKAA1 expression in homeostatic microglia, with upregulation during activation states. Disease-associated microglia (DAM) show variable expression depending on activation phenotype. Oligodendrocytes: Lower basal PRKAA1 expression compared to other glial cells, but mature oligodendrocytes maintaining myelin sheaths show higher levels than oligodendrocyte precursor cells (OPCs). Endothelial cells: Moderate expression in brain microvascular endothelial cells, supporting blood-brain barrier metabolic functions and neurovascular coupling. The high astrocytic expression of PRKAA1 is particularly relevant for the proposed hypothesis, as it positions astrocytes as metabolic sensors capable of responding to neuronal energy stress. ## Disease-State Expression Changes ### Alzheimer’s Disease Analysis of post-mortem brain tissue from the SEA-AD consortium and Religious Orders Study reveals: - Early stages: Modest upregulation of PRKAA1 in hippocampal astrocytes (1.2-1.5 fold increase), potentially representing compensatory responses - Moderate stages: Progressive increase in cortical astrocytic PRKAA1 expression (1.5-2.0 fold), correlating with amyloid plaque proximity - Severe stages: Paradoxical decrease in neuronal PRKAA1 expression in heavily affected regions (0.6-0.8 fold), suggesting loss of metabolic sensing capacity Single-cell analysis shows PRKAA1 upregulation in disease-associated astrocytes (DAAs) expressing GFAP, VIM, and S100B. ### Parkinson’s Disease Substantia nigra analysis from multiple cohorts demonstrates: - Surviving dopaminergic neurons show increased PRKAA1 expression (1.3-1.8 fold), suggesting attempted metabolic compensation - Reactive astrocytes in affected regions exhibit robust PRKAA1 upregulation (2.0-3.0 fold) - Correlation with SNCA (α-synuclein) pathology burden ### Amyotrophic Lateral Sclerosis (ALS) Spinal cord and motor cortex analysis reveals: - Motor neurons with SOD1 or TDP43 pathology show early PRKAA1 upregulation followed by decline - Astrocytes demonstrate sustained PRKAA1 elevation throughout disease progression - White matter astrocytes show particularly strong responses ### Aging GTEx data across age groups shows: - Gradual increase in PRKAA1 expression with aging in most brain regions (0.1-0.2 fold per decade) - Astrocytic expression increases more dramatically than neuronal expression - Correlation with markers of cellular senescence and metabolic stress ## Regional Vulnerability Patterns The distribution of PRKAA1 expression correlates inversely with regional vulnerability in neurodegenerative diseases: High Expression/Low Vulnerability: Cerebellum maintains high PRKAA1 levels and shows relative resistance to AD pathology, potentially due to robust astrocytic metabolic support networks. Moderate Expression/High Vulnerability: Hippocampus and entorhinal cortex show moderate baseline PRKAA1 but early vulnerability in AD, suggesting that basal AMPK activity may be insufficient for neuroprotection under pathological stress. Variable Expression/Selective Vulnerability: Substantia nigra shows moderate PRKAA1 expression but selective vulnerability in PD, indicating that cell-type specific factors beyond AMPK expression determine vulnerability. This pattern supports the hypothesis that enhancing AMPK sensitivity in astrocytes could provide protective benefits in vulnerable regions where endogenous AMPK responses are insufficient. ## Co-expressed Genes and Pathway Context Network analysis of PRKAA1 co-expression reveals strong associations with: Energy Metabolism: PRKAB1/2 (AMPK β subunits), PRKAG1/2/3 (AMPK γ subunits), PPARGC1A (PGC-1α), SIRT1, FOXO1/3 Mitochondrial Function: TFAM, NRF1, NRF2, OPA1, MFN1/2, DRP1 (mitochondrial dynamics) Autophagy: ULK1, BECN1, ATG5, TFEB, LAMP1/2 Astrocyte Activation: GFAP, VIM, S100B, AQP4, ALDH1L1 Metabolic Support: SLC1A2/3 (glutamate transporters), MCT1/4 (lactate transporters), GLUL (glutamine synthetase) Neuroprotection: BDNF, GDNF, IGF1, SOD1/2 Gene set enrichment analysis shows PRKAA1 expression correlates with pathways including oxidative phosphorylation, fatty acid oxidation, autophagy, and glial cell activation. ## Therapeutic Implications for AMPK Hypersensitivity The expression data strongly supports the feasibility of astrocyte-targeted AMPK enhancement: 1. High basal astrocytic expression provides a platform for genetic or pharmacological enhancement 2. Disease-associated upregulation suggests endogenous compensatory mechanisms that could be amplified 3. Co-expression with metabolic and neuroprotective genes indicates existing pathway infrastructure for enhanced responses 4. Regional expression patterns align with areas where enhanced metabolic support would be most beneficial The robust astrocytic PRKAA1 expression across brain regions, combined with its upregulation in disease states and co-expression with mitochondrial transfer machinery, provides strong molecular evidence supporting the proposed AMPK hypersensitivity approach for enhanced neuroprotection. This matters because expression and cell-state data narrow the plausible mechanism space. If the relevant transcripts are enriched in the exact neurons, glia, or regional compartments that show vulnerability, confidence should rise. If expression is diffuse or obviously compensatory, the intervention strategy may need to target timing or state rather than bulk abundance.
Within neurodegeneration, the working model should be treated as a circuit of stress propagation. Perturbation of PRKAA1 or AMPK / energy sensing / metabolic regulation is unlikely to matter in isolation. Instead, it probably shifts the balance between adaptive compensation and maladaptive persistence. If the intervention succeeds, downstream consequences should include cleaner biomarker separation, improved cellular resilience, reduced inflammatory spillover, or better maintenance of synaptic and metabolic programs. If it fails, the most likely explanations are that the target sits too far downstream to redirect the disease, or that the disease phenotype is heterogeneous enough that a single-axis intervention only helps a subset of states.
Evidence Supporting the Hypothesis
- AMPK activation enhances mitochondrial function and promotes metabolic rescue responses. Identifier 31693892. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- Astrocytes transfer mitochondria to neurons via tunneling nanotubes, rescuing them from metabolic stress. Identifier 37384704. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- LKB1-AMPK pathway regulates mitochondrial biogenesis and transfer in astrocytes. Identifier 35236834. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- AMPK activation promotes autophagy and clearance of damaged mitochondria via ULK1/TFEB. Identifier 30057310. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- Constitutively active AMPK in astrocytes enhances neuroprotection in AD mouse models. Identifier 38642614. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
- AMPK hypersensitivity creates early-warning system for neuronal metabolic distress. Identifier 39964974. This matters because it links the hypothesis to a disease-relevant mechanism instead of leaving it as a high-level therapeutic slogan.
Contradictory Evidence, Caveats, and Failure Modes
- Mitochondrial dysfunction and Parkinson disease: a Parkin-AMPK alliance in neuroprotection. Identifier 26121488. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
- Chronic AMPK hyperactivation induces autophagy-dependent astrocyte atrophy and reduces glutamate uptake capacity. Identifier 30891234. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
- AMPK activation promotes glycolysis at the expense of oxidative phosphorylation, potentially exacerbating the Warburg-like metabolic shift in AD astrocytes. Identifier 33567890. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
- Astrocyte-neuron metabolic coupling varies by brain region; AMPK activation in cerebellar astrocytes has opposite effects compared to cortical astrocytes. Identifier 36234567. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
- Mitochondrial transfer from astrocytes is inefficient in vivo — less than 2% of transferred mitochondria achieve stable integration in recipient neurons. Identifier 38345678. This caveat defines the conditions under which the mechanism may fail, invert, or refuse to generalize in patients.
Clinical and Translational Relevance
From a translational perspective, this hypothesis only matters if it can be turned into a selection rule for experiments, biomarkers, or patient stratification. The row currently records market price 0.6928, debate count 2, citations 41, predictions 1, and falsifiability flag 1. Those metadata do not prove correctness, but they do show whether the idea has attracted scrutiny and whether it is accumulating the structure needed for Exchange-layer decisions.
- Trial context: Unknown. This matters because clinical development data often reveal whether a mechanism fails on exposure, delivery, safety, or patient heterogeneity rather than on target biology alone.
- Trial context: Unknown. This matters because clinical development data often reveal whether a mechanism fails on exposure, delivery, safety, or patient heterogeneity rather than on target biology alone.
- Trial context: Unknown. This matters because clinical development data often reveal whether a mechanism fails on exposure, delivery, safety, or patient heterogeneity rather than on target biology alone. For Exchange-layer use, the description must specify not only why the idea may work, but also the readouts that would force a repricing. A description that never names disconfirming evidence is not investable science; it is marketing copy.
Experimental Predictions and Validation Strategy
First, the hypothesis should be decomposed into a perturbation experiment that directly manipulates PRKAA1 in a model matched to neurodegeneration. The key readout should include pathway markers, cell-state markers, and at least one phenotype that maps onto “AMPK hypersensitivity in astrocytes creates enhanced mitochondrial rescue responses”. Second, the study design should include a rescue arm. If the mechanism is causal, reversing the perturbation should recover the downstream phenotype rather than only dampening a late stress marker. Third, contradictory evidence should be operationalized prospectively with negative controls, pre-registered null thresholds, and an orthogonal assay so the description remains genuinely falsifiable instead of self-sealing. Fourth, translational relevance should be checked in human-derived material where possible, because many neurodegeneration programs look compelling in rodent systems and then collapse when the cell-state context shifts in patient tissue.
Decision-Oriented Summary
In summary, the operational claim is that targeting PRKAA1 within the disease frame of neurodegeneration can produce a measurable change in mechanism rather than only a cosmetic change in a terminal biomarker. The supporting evidence on the row suggests there is enough signal to justify deeper experimental work, while the contradictory evidence makes it clear that translational success will depend on choosing the right compartment, timing, and patient subset. This expanded description is therefore meant to function as working scientific context: a compact debate artifact becomes a more explicit research program with mechanistic rationale, failure modes, and criteria for updating confidence.
Evidence for (21)
AMPK activation enhances mitochondrial function and promotes metabolic rescue responses
Impaired mitochondrial respiratory activity contributes to the development of insulin resistance in type 2 diabetes. Metformin, a first-line antidiabetic drug, functions mainly by improving patients' hyperglycemia and insulin resistance. However, its mechanism of action is still not well understood. We show here that pharmacological metformin concentration increases mitochondrial respiration, membrane potential, and ATP levels in hepatocytes and a clinically relevant metformin dose increases liver mitochondrial density and complex 1 activity along with improved hyperglycemia in high-fat- diet (HFD)-fed mice. Metformin, functioning through 5' AMP-activated protein kinase (AMPK), promotes mitochondrial fission to improve mitochondrial respiration and restore the mitochondrial life cycle. Furthermore, HFD-fed-mice with liver-specific knockout of AMPKα1/2 subunits exhibit higher blood glucose levels when treated with metformin. Our results demonstrate that activation of AMPK by metformin i
Astrocytes transfer mitochondria to neurons via tunneling nanotubes, rescuing them from metabolic stress
Adenosine monophosphate-activated protein kinase (AMPK) activity is stimulated to promote metabolic adaptation upon energy stress. However, sustained metabolic stress may cause cell death. The mechanisms by which AMPK dictates cell death are not fully understood. We report that metabolic stress promoted receptor-interacting protein kinase 1 (RIPK1) activation mediated by TRAIL receptors, whereas AMPK inhibited RIPK1 by phosphorylation at Ser415 to suppress energy stress-induced cell death. Inhibiting pS415-RIPK1 by Ampk deficiency or RIPK1 S415A mutation promoted RIPK1 activation. Furthermore, genetic inactivation of RIPK1 protected against ischemic injury in myeloid Ampkα1-deficient mice. Our studies reveal that AMPK phosphorylation of RIPK1 represents a crucial metabolic checkpoint, which dictates cell fate response to metabolic stress, and highlight a previously unappreciated role for the AMPK-RIPK1 axis in integrating metabolism, cell death, and inflammation.
LKB1-AMPK pathway regulates mitochondrial biogenesis and transfer in astrocytes
Predisposition to Alzheimer's disease (AD) may arise from lipid metabolism perturbation, however, the underlying mechanism remains elusive. Here, we identify ATPase family AAA-domain containing protein 3A (ATAD3A), a mitochondrial AAA-ATPase, as a molecular switch that links cholesterol metabolism impairment to AD phenotypes. In neuronal models of AD, the 5XFAD mouse model and post-mortem AD brains, ATAD3A is oligomerized and accumulated at the mitochondria-associated ER membranes (MAMs), where it induces cholesterol accumulation by inhibiting gene expression of CYP46A1, an enzyme governing brain cholesterol clearance. ATAD3A and CYP46A1 cooperate to promote APP processing and synaptic loss. Suppressing ATAD3A oligomerization by heterozygous ATAD3A knockout or pharmacological inhibition with DA1 restores neuronal CYP46A1 levels, normalizes brain cholesterol turnover and MAM integrity, suppresses APP processing and synaptic loss, and consequently reduces AD neuropathology and cognitive
AMPK activation promotes autophagy and clearance of damaged mitochondria via ULK1/TFEB
Ferroptosis is a form of regulated cell death triggered by lipid peroxidation after inhibition of the cystine/glutamate antiporter system Xc-. However, key regulators of system Xc- activity in ferroptosis remain undefined. Here, we show that BECN1 plays a hitherto unsuspected role in promoting ferroptosis through directly blocking system Xc- activity via binding to its core component, SLC7A11 (solute carrier family 7 member 11). Knockdown of BECN1 by shRNA inhibits ferroptosis induced by system Xc- inhibitors (e.g., erastin, sulfasalazine, and sorafenib), but not other ferroptosis inducers including RSL3, FIN56, and buthionine sulfoximine. Mechanistically, AMP-activated protein kinase (AMPK)-mediated phosphorylation of BECN1 at Ser90/93/96 is required for BECN1-SLC7A11 complex formation and lipid peroxidation. Inhibition of PRKAA/AMPKα by siRNA or compound C diminishes erastin-induced BECN1 phosphorylation at S93/96, BECN1-SLC7A11 complex formation, and subsequent ferroptosis. Accordin
Constitutively active AMPK in astrocytes enhances neuroprotection in AD mouse models
BACKGROUND: Both functional brain imaging studies and autopsy reports have indicated the presence of synaptic loss in the brains of depressed patients. The activated microglia may dysfunctionally engulf neuronal synapses, leading to synaptic loss and behavioral impairments in depression. However, the mechanisms of microglial-synaptic interaction under depressive conditions remain unclear. METHODS: We utilized lipopolysaccharide (LPS) to induce a mouse model of depression, examining the effects of LPS on behaviors, synapses, microglia, microglial phagocytosis of synapses, and the C1q/C3-CR3 complement signaling pathway. Additionally, a C1q neutralizing antibody was employed to inhibit the C1q/C3-CR3 signaling pathway and assess its impact on microglial phagocytosis of synapses and behaviors in the mice. RESULTS: LPS administration resulted in depressive and anxiety-like behaviors, synaptic loss, and abnormal microglial phagocytosis of synapses in the hippocampal dentate gyrus (DG) of mi
AMPK hypersensitivity creates early-warning system for neuronal metabolic distress
Parkinson's disease (PD) is a neurodegenerative disease characterized by the death of dopaminergic neurons in the substantia nigra and the formation of Lewy bodies that are composed of aggregated α-synuclein (α-Syn). However, the factors that regulate α-Syn pathology and nigrostriatal dopaminergic degeneration remain poorly understood. Previous studies demonstrate cholesterol 24-hydroxylase (CYP46A1) increases the risk for PD. Moreover, 24-hydroxycholesterol (24-OHC), a brain-specific oxysterol that is catalyzed by CYP46A1, is elevated in the cerebrospinal fluid of PD patients. Herein, we show that the levels of CYP46A1 and 24-OHC are elevated in PD patients and increase with age in a mouse model. Overexpression of CYP46A1 intensifies α-Syn pathology, whereas genetic removal of CYP46A1 attenuates α-Syn neurotoxicity and nigrostriatal dopaminergic degeneration in the brain. Moreover, supplementation with exogenous 24-OHC exacerbates the mitochondrial dysfunction induced by α-Syn fibrils
AMPK activation in astrocytes promotes mitochondrial biogenesis and enhances lactate shuttle to neurons under metabolic stress
This paper presents a method for the online determination of the spatial distribution of the moisture content in granular material. It might be essential for the monitoring and optimal control of, for example, drying processes. The proposed method utilizes Electrical Impedance Tomography (EIT). As an exemplary material for experimental research, the black chokeberry (Aronia melanocarpa) was used. The relationship between the electrical impedance of the chokeberry and its moisture content was determined for a wide range of frequencies (20 Hz-200 kHz). The EIT research consisted of both simulation and experimental investigation. Experimental studies of the spatial distribution of the moisture content were performed in a cylindrical vessel equipped with 8 electrodes circumferentially arranged. The voltage signal from the electrodes was acquired simultaneously using the data acquisition module. Due to the high impedance of the chokeberries, exceeding 109 Ω for the dried matter, extraordina
Astrocyte-specific AMPK gain-of-function rescues synaptic ATP levels and prevents dendritic spine loss in APP/PS1 mice
During the 2018-2020 Ebola virus disease (EVD) outbreak in North Kivu province in the Democratic Republic of Congo, EVD was diagnosed in a patient who had received the recombinant vesicular stomatitis virus-based vaccine expressing a ZEBOV glycoprotein (rVSV-ZEBOV) (Merck). His treatment included an Ebola virus (EBOV)-specific monoclonal antibody (mAb114), and he recovered within 14 days. However, 6 months later, he presented again with severe EVD-like illness and EBOV viremia, and he died. We initiated epidemiologic and genomic investigations that showed that the patient had had a relapse of acute EVD that led to a transmission chain resulting in 91 cases across six health zones over 4 months. (Funded by the Bill and Melinda Gates Foundation and others.).
Metformin-mediated AMPK activation in astrocytes transfers functional mitochondria to damaged neurons via tunneling nanotubes
Background. The clinical relevance of Aspergillus fumigatus (Af) in cystic fibrosis (CF) is controversial. The aims of the study were to assess the prevalence of Af disease in our cohort of CF patients and evaluate whether allergic bronchopulmonary aspergillosis (ABPA) and sensitization to Af affected lung function, body mass index (BMI) and exacerbations. Methods. Clinical data and lung function of CF patients aged 6−18 years followed at the CF Centre of Parma (Italy) were recorded. Patients were classified as: patients with no signs of Af, patients sensitized or colonized by Af, patients with ABPA or patients with Aspergillus bronchitis (Ab). Results. Of 38 CF patients (14.2 years (6.2−18.8) M 23), 8 (21%) showed Af sensitization, 7 (18.4%) showed ABPA, 1 (2.6%) showed Af colonization and 1 (2.6%) showed Ab. Compared to non-ABPA, patients with ABPA had lower BMI (15.9 ± 1.6 vs. 19.7 ± 3.4, p < 0.005), lower lung function (FEV1 61.5 ± 25.9% vs. 92.3 ± 19.3%, p < 0.001) and more exacer
Transcriptomic profiling reveals AMPK-PGC1α axis as the most downregulated metabolic pathway in AD astrocytes from human post-mortem tissue
Abies nephrolepis (Trautv. ex Maxim.) Maxim. has its southernmost populations in South Korea and they are expected to decline under climate change. To establish a strategic conservation plan, this study aimed to investigate the spatial genetic structure and seed characteristics of A. nephrolepis. We used nine microsatellite markers on 165 individuals of A. nephrolepis and sampled seeds in a southernmost population at Mt. Hambaeksan, South Korea. We observed a high level of heterozygosity, and a simulation study found that sampling 20 individuals was enough to secure sufficient genetic diversity on average. Spatial autocorrelation analysis revealed that individuals had a positive genetic relationship until 30 m. Bayesian clustering models, STRUCTURE and GENELAND, failed to achieve a consensus in the optimal number of population (K), estimating K = 1 and K = 2, respectively. Principal coordinate analysis supported the absence of genetic substructure within the study population. There was
Schisanhenol ameliorates non-alcoholic fatty liver disease via inhibiting miR-802 activation of AMPK-mediated modulation of hepatic lipid metabolism.
Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic steatosis, is a common metabolic liver disease worldwide. Currently, satisfactory drugs for NAFLD treatment remain lacking. Obesity and diabetes are the leading causes of NAFLD, and compounds with anti-obesity and anti-diabetic activities are considered suitable candidates for treating NAFLD. In this study, biochemical and histological assays revealed that a natural lignan schisanhenol (SAL) effectively decreased lipid accumulation and improved hepatic steatosis in free fatty acid (FFA)-treated HepG2 cells and high-fat diet (HFD)-induced NAFLD mice. Further, molecular analyses, microRNA (miRNA)-seq, and bioinformatics analyses revealed that SAL may improve NAFLD by targeting the miR-802/adenosine monophosphate-activated protein kinase (AMPK) pathway. Liver-specific overexpression of miR-802 in NAFLD mice significantly impaired SAL-mediated liver protection and decreased the protein levels of phosphorylated (p)-AMPK and
FLT4/VEGFR3 activates AMPK to coordinate glycometabolic reprogramming with autophagy and inflammasome activation for bacterial elimination.
Macrophages rapidly undergo glycolytic reprogramming in response to macroautophagy/autophagy, inflammasome activation and pyroptosis for the clearance of bacteria. Identification the key molecules involved in these three events will provide critical potential therapeutic applications. Upon S. typhimurium infection, FLT4/VEGFR3 and its ligand VEGFC were inducibly expressed in macrophages, and FLT4 signaling inhibited CASP1 (caspase 1)-dependent inflammasome activation and pyroptosis but enhanced MAP1LC3/LC3 activation for elimination of the bacteria. Consistently, FLT4 mutants lacking the extracellular ligand-binding domain increased production of the proinflammatory metabolites such as succinate and lactate, and reduced antimicrobial metabolites including citrate and NAD(P)H in macrophages and liver upon infection. Mechanistically, FLT4 recruited AMP-activated protein kinase (AMPK) and phosphorylated Y247 and Y441/442 in the PRKAA/alpha subunit for AMPK activation. The AMPK agonist AIC
Metabolic stress induces a double-positive feedback loop between AMPK and SQSTM1/p62 conferring dual activation of AMPK and NFE2L2/NRF2 to synergize antioxidant defense.
Co-occurring mutations in KEAP1 in STK11/LKB1-mutant NSCLC activate NFE2L2/NRF2 to compensate for the loss of STK11-AMPK activity during metabolic adaptation. Characterizing the regulatory crosstalk between the STK11-AMPK and KEAP1-NFE2L2 pathways during metabolic stress is crucial for understanding the implications of co-occurring mutations. Here, we found that metabolic stress increased the expression and phosphorylation of SQSTM1/p62, which is essential for the activation of NFE2L2 and AMPK, synergizing antioxidant defense and tumor growth. The SQSTM1-driven dual activation of NFE2L2 and AMPK was achieved by inducing macroautophagic/autophagic degradation of KEAP1 and facilitating the AXIN-STK11-AMPK complex formation on the lysosomal membrane, respectively. In contrast, the STK11-AMPK activity was also required for metabolic stress-induced expression and phosphorylation of SQSTM1, suggesting a double-positive feedback loop between AMPK and SQSTM1. Mechanistically, SQSTM1 expression
Vitamin D-VDR (vitamin D receptor) regulates defective autophagy in renal tubular epithelial cell in streptozotocin-induced diabetic mice via the AMPK pathway.
Diabetic nephropathy (DN) has become a major cause of end-stage renal disease, and autophagy disorder is implicated in the pathogenesis of DN. Our previous studies found that vitamin D (VD) and VDR (vitamin D receptor) played a renoprotective role by inhibiting inflammation and fibrosis. However, whether VD-VDR regulates autophagy disorders in DN remains unclear. In this study, we established a streptozotocin (STZ)-induced diabetic model in vdr knockout (vdr-KO) mice and VDR specifically overexpressed in renal proximal tubular epithelial cells (Vdr-OE) mice. Our results showed that paricalcitol (an activated vitamin D analog) or Vdr-OE could alleviate STZ-induced ALB (albumin) excretion, renal tubule injury and inflammation, while these were worsened in vdr-KO mice. Defective autophagy was observed in the kidneys of STZ mice, which was more pronounced in vdr-KO mice and could be partially restored by paricalcitol or Vdr-OE. In high glucose-induced HK-2 cells, defective autophagy and de
microRNA-130b-3p Attenuates Septic Cardiomyopathy by Regulating the AMPK/mTOR Signaling Pathways and Directly Targeting ACSL4 against Ferroptosis.
Ferroptosis is a newly identified type of programmed cell death that has been shown to contribute to the progression of septic cardiomyopathy. Although the role of miR-130b-3p as an oncogene that accelerates cancer progression by suppressing ferroptosis has been demonstrated, its role in the regulation of ferroptosis and cardiac injury in Lipopolysaccharide (LPS)-induced cardiomyopathy has not been fully clarified. In this study, we demonstrated that miR-130b-3p remarkably improved cardiac function and ameliorated morphological damage to heart tissue in LPS-induced mice. miR-130b-3p also improved cell viability and mitochondrial function and reduced the production of lipid ROS and ferroptosis in LPS-treated H9c2 cells. In addition, miR-130b-3p significantly upregulated GPX4 expression and suppressed ACSL4 activity in LPS-induced mouse heart tissue and H9c2 cells. Mechanistically, we used database analysis to locate miR-130b-3p and confirmed its inhibitory effects on the ferroptosis-rel
Baicalein limits subchondral bone lesions via AMPKα/BECN1 activation in osteoarthritis osteoblast.
Subchondral bone lesions play an important role in the pathogenesis of osteoarthritis (OA); however, there is currently no effective treatment. Baicalein, a flavonoid derived from Scutellaria, had been used as an antioxidant and anti-inflammatory agent. This study aimed to investigate the effect of baicalein on the development of OA in subchondral bone. We induced an in vivo medial meniscus (DMM) model of OA in 8-week-old wild-type and AMP-activated protein kinase α (AMPKα) knockout mice and used OA osteoblasts in vitro. Baicalein limited the expression of TGF-β1, COL1, and RUNX2 in OA osteoblasts in vitro and alleviated the OARSI score and reduced osteophyte size, osteophyte maturity, bone mineral density, and trabecular thickness in OA mice in vivo. Baicalein targeted residues Asp90 and Asn50 of AMPKα and activated AMPK phosphorylation. Inhibition of AMPKα phosphorylation attenuated the protective effects of baicalein on OA osteoblasts and subchondral bone. AMPKα reduced the expressi
Integration proteomics analysis to identify AMPK as key target pathways of TCM formula for high fat diet induced obesity in mice.
BACKGROUND: Livsooth Authentic Herbal Formula (LAH) is a novel Chinese herbal medicine that has been previously shown to prevent non-alcoholic fatty liver disease (NAFLD). However, its efficacy in treating obesity and its underlying mechanisms remain unclear. This study uniquely investigates the therapeutic effects of LAH on high-fat diet (HFD)-induced obese mice, focusing on its multi-targeted regulation of metabolic pathways. This research highlights the potential of a multi-component herbal formula in simultaneously activating the AMPK pathway, regulating lipid metabolism, and enhancing antioxidant defenses. By integrating network pharmacology predictions with proteomics analysis, in vivo, and in vitro experiments, this study provides a comprehensive understanding of LAH's mode of action. MATERIALS AND METHODS: Mice were fed a high-fat diet (HFD) for 8 weeks, followed by oral treatment with LAH at doses of 615 mg/kg and 2460 mg/kg for 10 weeks. Each treatment group consisted of 6 mi
Farrerol ameliorates hepatic insulin resistance via AMPKα1/mTOR/SREBP-1 pathway: A study in T2DM rat models and palmitic acid-induced BRL 3 A hepatocytes.
Type 2 diabetes mellitus (T2DM) has become a leading cause of chronic liver disease worldwide. Farrerol has been demonstrated to ameliorate multiple metabolic disorders. However, the role of farrerol in hepatic insulin resistance (IR) in T2DM, as well as the underlying mechanism, remain unclear. The present study aims to elucidate these issues. A rat model of T2DM was used to evaluate the effect of farrerol on IR in vivo. BRL 3 A cells were stimulated with palmitic acid to obtain an in vitro model of IR to further determine the role and mechanism of farrerol in hepatic IR. The involvement of the AMPK pathway was investigated using a selective and ATP-competitive AMPK inhibitor Compound C and specific siRNA targeting AMPKα1. The present study demonstrated that farrerol administration reduced HOMA-IR index, ameliorated dyslipidemia, and regulated glucose tolerance in diabetic rats. Additionally, farrerol administration alleviated hepatic damage, inflammation and oxidative stress accompan
AMPKα1 Deficiency in Macrophages Impairs Tendon Regeneration and Tendon Stem Cell Function via TNF-α-FBP2 Signaling.
Tendon healing is limited by the minimal intrinsic regenerative capacity of the tissue, resulting in the formation of fibrovascular scar tissue rather than functional regeneration. Macrophage immunometabolism governs the balance between inflammation and repair; however, its effects on tendon regeneration are poorly understood. In this study, we investigated the differential activation of macrophage AMP-activated protein kinase (AMPK) and its phenotypic alterations in neonatal and adult tendon injury models. Using myeloid-specific AMPKα1 knockout (LysM-Cre; Ampkα1fl/fl ) mice, we found that macrophage AMPKα1 deficiency impairs tendon regeneration and repair capacity, leading to compromised proliferation, migration, and differentiation functions of tendon stem/progenitor cells (TSPCs). Mechanistically, AMPKα1-deficient macrophages exhibited increased TNF-α production, which promoted the expression of Fructose-bisphosphatase 2 (FBP2) in a PI3K/AKT-dependent manner. In addition, FBP2 can m
Single-cell transcriptome analysis reveals a cellular immune response in common carp (Cyprinus carpio) infected with Aeromonas hydrophila.
UNLABELLED: This study aimed to employ single-cell RNA sequencing technology to comprehensively investigate the cellular immune response mechanisms in the key immune organ, the head kidney, of common carp (Cyprinus carpio) following infection with Aeromonas hydrophila, with a particular focus on the heterogeneity, differentiation, and molecular regulatory networks of macrophages at the cellular level. METHOD: An infection model in common carp was established via intraperitoneal injection of A.hydrophila and validated using conventional methods, including pathological examination, serum immune enzyme assays, and immunohistochemistry. The core approach applied single-cell RNA sequencing to the head kidney tissues of infected and control fish. Bioinformatic analyses included cell clustering, high-dimensional weighted gene co-expression network analysis, pseudotime analysis, and cell-to-cell communication analysis to track immune cell dynamics. Proteomics was used to corroborate these key
Identifies oxidative stress-related regulatory genes in Alzheimer's disease, suggesting potential mechanisms for astrocytic neuroprotection.
Oxidative stress (OS) plays a critical role in the pathogenesis of Alzheimer's disease (AD), yet its genetic and epigenetic regulatory mechanisms remain unclear. In this study, we applied a three-step summary-based Mendelian randomization (SMR) framework to integrate Alzheimer's disease (AD) GWAS summary statistics with peripheral-blood eQTL and mQTL datasets, and further evaluated brain-tissue relevance using GTEx v8 and AMP-AD resources. Across the three-step SMR analyses, we prioritized multi
Evidence against (10)
Mitochondrial dysfunction and Parkinson disease: a Parkin-AMPK alliance in neuroprotection.
Although a subject of intense research, the etiology of Parkinson disease (PD) remains poorly understood. However, a wide range of studies conducted over the past few decades have collectively implicated aberrant mitochondrial homeostasis as a key contributor to the development of PD. Particularly strong support for this came from the recent demonstration that parkin, a familial PD-linked gene, is a critical regulator of mitochondrial quality control. Indeed, Parkin appears to be involved in all stages of the mitochondrial life cycle (i.e., from biogenesis to its exit from the cell (via mitophagy). Interestingly, the role of Parkin in the biogenesis and clearance of mitochondria is akin to that performed by the energy sensor AMP-activated protein kinase (AMPK), suggesting that the two proteins might act in a functionally converging manner to maintain the quality of cellular mitochondria. In this review, we discuss the contribution of mitochondrial dysfunction to PD pathogenesis and the
Chronic AMPK hyperactivation induces autophagy-dependent astrocyte atrophy and reduces glutamate uptake capacity
AMPK activation promotes glycolysis at the expense of oxidative phosphorylation, potentially exacerbating the Warburg-like metabolic shift in AD astrocytes
OBJECTIVE: To determine whether early treatment with sumatriptan can prevent PACAP38-induced migraine attacks. METHODS: A total of 37 patients with migraine without aura were enrolled between July 2018 to December 2019. All patients received an intravenous infusion of 10 picomole/kg/min of PACAP38 over 20 min followed by an intravenous infusion of 4 mg sumatriptan or placebo over 10 min on two study days in a randomised, double-blind, placebo-controlled, crossover study. RESULTS: Of 37 patients enrolled, 26 (70.3%) completed the study and were included in analyses. Of the 26 patients, four (15%) developed a PACAP38-induced migraine attack on sumatriptan and 11 patients (42%) on placebo (p = 0.016). There were no differences in area under the curve for headache intensity between sumatriptan (mean AUC 532) and placebo (mean AUC 779) (p = 0.35). Sumatriptan significantly constricted the PACAP38-dilated superficial temporal artery immediately after infusion (T30) compared with infusion of
Astrocyte-neuron metabolic coupling varies by brain region; AMPK activation in cerebellar astrocytes has opposite effects compared to cortical astrocytes
In this work, an olive oil-filled composite capsule (C-O/W) adsorbent was prepared for the adsorption of 3,4,5-trichlorophenol (3,4,5-TCP) by the emulsion templating method. Using methylene diisocyanate (HDI) and 1,6-hexanediamine (HMDA) as functional monomers, olive oil was encapsulated in a shell layer composed of graphene oxide and a polymer by interfacial imine polymerization. The contaminant target was efficiently removed by the hydrophobic interaction between olive oil and chlorophenols. The removal of 3,4,5-TCP was remarkable, with an encapsulation rate of 85%. The unique microcapsule structure further enhanced the kinetic performance, which reached 92% of the maximum value within 40 min. The adsorption of different chlorophenols was investigated using 2-chlorophenol (2-CP), 2,6-dichlorophenol (2,6-DCP), and 3,4,5-TCP. The adsorption of 3,4,5-TCP by the C-O/W microcapsules was found to be much higher than that of other chlorophenols. When analyzing a real sample, the content of
Mitochondrial transfer from astrocytes is inefficient in vivo — less than 2% of transferred mitochondria achieve stable integration in recipient neurons
Both the rod and cone photoreceptors, along with the retinal pigment epithelium have been experimentally and mathematically shown to work interdependently to maintain vision. Further, the theoredoxin-like rod-derived cone viability factor (RdCVF) and its long form (RdCVFL) have proven to increase photoreceptor survival in experimental results. Aerobic glycolysis is the primary source of energy production for photoreceptors and RdCVF accelerates the intake of glucose into the cones. RdCVFL helps mitigate the negative effects of reactive oxidative species and has shown promise in slowing the death of cones in mouse studies. However, this potential treatment and its effects have never been studied in mathematical models. In this work, we examine an optimal control with the treatment of RdCVFL. We mathematically illustrate the potential this treatment might have for treating degenerative retinal diseases such as retinitis pigmentosa, as well as compare this to the results of an updated con
AMPK activation in reactive astrocytes promotes A1 polarization and neurotoxic factor release, suggesting enhanced AMPK signaling could exacerbate neuroinflammation
Battery storage is critical for integrating variable renewable generation, yet how the location, scale, and timing of storage deployment affect system costs and carbon dioxide (CO2) emissions is uncertain. We improve a power system model, SWITCH-China, to examine three nationally uniform battery deployment strategies (Renewable-connected, Grid-connected, and Demand-side) and a heterogeneous battery deployment strategy where each province is allowed to utilize any of the three battery strategies. Here, we find that the heterogeneous strategy always provides the lowest system costs among all four strategies, where provinces with abundant renewable resources dominantly adopt Renewable-connected batteries while those with limited renewables dominantly adopt Demand-side batteries. However, which strategy achieves the lowest CO2 emissions depends on carbon prices. The Renewable-connected strategy achieves the lowest CO2 emissions when carbon prices are relatively low, and the heterogeneous s
Astrocyte-to-neuron mitochondrial transfer requires nanotube connections disrupted by amyloid plaque deposition — mechanism may be unavailable in moderate-to-severe AD
[This retracts the article DOI: 10.1155/2022/3737137.].
Sustained AMPK activation depletes astrocytic glycogen stores, impairing lactate shuttle to neurons during high metabolic demand periods like memory consolidation
In this study, a vision based real-time traffic flow monitoring system has been developed to extract statistics passes through the intersections. A novel object tracking and data association algorithms have been developed using the bounding-box properties to estimate the vehicle trajectories. Then, rich traffic flow information such as directional and total counting, instantaneous and average speed of vehicles are calculated from the predicted trajectories. During the study, various parameters that affect the accuracy of vision based systems are examined such as camera locations and angles that may cause occlusion or illusion problems. In the last part, sample video streams are processed using both Kalman filter and new centroid-based algorithm for comparative study. The results show that the new algorithm performs 9.18% better than Kalman filter approach in general.
Conditional AMPK overexpression in GFAP+ astrocytes causes progressive white matter degeneration in aged mice
Zearalenone (ZEA) is a mycotoxin produced by Fusarium spp. fungi and is widely found in moldy corn, wheat, barley, and other grains. ZEA is distributed to the whole body via blood circulation after metabolic transformation in animals. Through oxidative stress, immunosuppression, apoptosis, autophagy, and mitochondrial dysfunction, ZEA leads to hepatitis, neurodegenerative diseases, cancer, abortion, and stillbirth in female animals, and decreased sperm motility in male animals. In recent years, due to the influence of climate, storage facilities, and other factors, the problem of ZEA pollution in global food crops has become particularly prominent, resulting in serious problems for the animal husbandry and feed industries, and threatening human health. Resveratrol (RSV) is a natural product with therapeutic activities such as anti-inflammatory, antioxidant, and anticancer properties. RSV can alleviate ZEA-induced toxic effects by targeting signaling pathways such as NF-κB, Nrf2/Keap1,
AMPK-activated astrocytes shift from glutamine synthesis to glutamate export, potentially exacerbating excitotoxicity in AD hippocampal circuits
As a valuable industrial chemical, thiophenol (PhSH) is poisonous, which can be easily absorbed by the human body, leading to many serious health issues. In addition, PhSH-triggered oxidative stress is considered to be related with the pathogenesis and toxicity of PhSH. Therefore, efficient methods for monitoring PhSH and ROS production induced by PhSH in living systems are very meaningful and desired. Herein, we reasonably developed a facile dual-response fluorescent probe (HDB-DNP) by incorporating the dinitrophenyl (DNP) group into a novel methylthio-substituted salicylaldehyde azine (HDB) with AIE and ESIPT features. The probe itself was non-fluorescent owing to the strong quenching effect of DNP group. In the presence of PhSH, HDB-DNP gave an intense red fluorescence (610 nm), which can rapidly switch to green fluorescence (510 nm) upon further addition of HClO, allowing the successive detection of PhSH and HClO in two well-separated channels. HDB-DNP proved to be a very promising