AMPK Activation Research Articles

Cordycepin generally inhibits growth factor signal transduction in a systems pharmacology study.

Cordycepin (3' deoxyadenosine) has been widely researched as a potential cancer therapy, but many diverse mechanisms of action have been proposed. Here, we confirm that cordycepin triphosphate is likely to be the active metabolite of cordycepin and that it consistently represses growth factor-induced gene expression. Bioinformatic analysis, quantitative PCR and western blotting confirmed that cordycepin blocks the PI3K/AKT/mTOR and/or MEK/ERK pathways in six cell lines and that AMPK activation is not required. The effects of cordycepin on translation through mTOR pathway repression were detectable within 30 min, indicating a rapid process. These data therefore indicate that cordycepin has a universal mechanism of action, acting as cordycepin triphosphate on an as yet unknown target molecule involved in growth factor signalling.

Lactobacillus plantarum and Bifidobacterium longum Alleviate High-Fat Diet-Induced Obesity and Depression/Cognitive Impairment-like Behavior in Mice by Upregulating AMPK Activation and Downregulating Adipogenesis and Gut Dysbiosis

Lactobacillus plantarum and Bifidobacterium longum Alleviate High-Fat Diet-Induced Obesity and Depression/Cognitive Impairment-like Behavior in Mice by Upregulating AMPK Activation and Downregulating Adipogenesis and Gut Dysbiosis

Bioactive Compounds Aimed at the AMPK Pathway: A Window into their Therapeutic Potential

Abstract: Current investigations have proposed that focusing on malignancy cell metabolism is an elective restorative methodology in cancer treatment. AMPK is the significant energy sensor regulating ordinary as well as malignancy cell metabolism. Drugs as AMPK activators can quell malignancy cell development through the various signalling cascade. AMPK enactment in light of natural AMPK activators, for example, BME, ICT, Thymoquinone, has been displayed to constrict mTOR, approving that BME can restrain cell development in ovarian malignant growth cells utilizing suppressing mTOR-mediated protein translation process. Nutraceuticals as well as traditional medicines operate as natural AMPK activators that regulate AMPK movement through a mechanism that is independent of AMP. These naturally occuring AMPK activators might straightforwardly actuate AMPK through single or more than one mechanism in AMPK initiation. Exploring the synergistic effects of compounds with existing cancer treatments could open new avenues for combinatorial therapy, potentially enhancing efficacy and reducing side effects. Moreover, understanding the precise molecular pathways through which these natural AMPK activators exert their effects will be crucial in designing targeted therapies that maximize their therapeutic potential. The integration of these nutraceuticals into standard cancer treatment protocols requires rigorous clinical trials to establish their safety, optimal dosing, and long-term benefits in cancer patients. With further investigation, the possibility of using natural AMPK activators in addition to traditional medicines could transform cancer treatment by providing more patient-friendly and comprehensive options.

Alcohol induces p53-mediated apoptosis in neural crest by stimulating an AMPK-mediated suppression of TORC1, S6K, and ribosomal biogenesis

Prenatal alcohol exposure is a leading cause of permanent neurodevelopmental disability and can feature distinctive craniofacial deficits that partly originate from the apoptotic deletion of craniofacial progenitors, a stem cell lineage called the neural crest (NC). We recently demonstrated that alcohol causes nucleolar stress in NC through its suppression of ribosome biogenesis (RBG) and this suppression is causative in their p53/MDM2-mediated apoptosis. Here, we show that this nucleolar stress originates from alcohol’s activation of AMPK, which suppresses TORC1 and the p70/S6K-mediated stimulation of RBG. Alcohol-exposed cells of the pluripotent, primary cranial NC line O9-1 were evaluated with respect to their S6K, TORC1, and AMPK activity. The functional impact of these signals with respect to RBG, p53, and apoptosis were assessed using gain-of-function constructs and small molecule mediators. Alcohol rapidly (<2hr) increased pAMPK, pTSC2, and pRaptor, and reduced both total and pS6K in NC cells. These changes persisted for at least 12hr to 18hr following alcohol exposure. Attenuation of these signals via gain- or loss-of-function approaches that targeted AMPK, S6K, or TORC1 prevented alcohol’s suppression of rRNA synthesis and the induction of p53-stimulated apoptosis. We conclude that alcohol induces ribosome dysbiogenesis and activates their p53/MDM2-mediated apoptosis via its activation of pAMPK, which in turn activates TSC2 and Raptor to suppress the TORC1/S6K-mediated promotion of ribosome biogenesis. This represents a novel mechanism underlying alcohol’s neurotoxicity and is consistent with findings that TORC1/S6K networks are critical for cranial NC survival.

SARM1 Deficiency Induced Depressive-like Behavior via AMPKα/p-eEF2 axis to Synapse Dysfunction

Sterile Alpha and TIR Motif Containing 1 (SARM1) are proteins implicated in various neurological processes; however, their role in depression remains unexplored. This study investigated the contribution of SARM1 to depressive-like behaviors in a chronic stress-induced depression model and SARM1 knockout (KO) mice. Depressive-like behaviors were assessed using a battery of behavioral tests, including the Open Field Test (OFT), the Forced Swim Test (FST), the Sucrose Preference Test (SPT), and the Tail Suspension Test (TST). Mitochondrial energy metabolism alteration, cytokine level changes, and other related molecular signalling protein expression were evaluated using ELISA and western blotting techniques to investigate the underlying mechanisms. Behavioral assessments (OFT, FST, SPT, TST) revealed depressive-like phenotypes in SARM1 KO mice, accompanied by altered mitochondrial energy metabolism (NAD+, ATP) in the cortex. Intriguingly, SARM1 depletion led to peripheral inflammation, as evidenced by elevated cytokine levels in plasma but not in brain regions (cortex). In addition, we found dysregulated energy metabolism, AMPK signaling, and synaptic plasticity in the cortex of SARM1 KO mice. Notably, AICAR (Acadesine), an AMPK activator, ameliorated depressive-like behaviors and synaptic dysfunction, while Compound C, an AMPK inhibitor, reversed these effects. Additionally, NH125, an eEF2 kinase inhibitor, improved depressive-like behaviors in SARM1 KO mice. These findings demonstrate that SARM1 is critical in regulating depressive-like behaviours through the AMPKα/p-eEF2 signalling pathway. Targeting AMPK signaling and synaptic function may offer novel therapeutic avenues for depression.

In-vitro modulation of glucose and lipid metabolism by Lentinula edodes extracts in obesity and type 2 diabetes models

IntroductionLentinula edodes (shiitake mushroom) has been integral to Traditional Chinese Medicine (TCM) for centuries, with its cultivation dating back to the Song dynasty (960–1127) in China. Traditionally valued for its immune-boosting properties, L. edodes is now being studied for its potential in managing metabolic disorders like obesity and type 2 diabetes. This study examines the effects of L. edodes fruiting body extract on key metabolic pathways related to glucose metabolism and lipid regulation. MethodsFruiting body extracts of Lentinula edodes including water, ethanolic, methanolic, and hydroalcoholic (50:50, 75:25, 25:75) were tested on L6 myoblasts. The study evaluated glucose uptake, GLUT4 expression, p-AMPK activation, and gene expression levels of PPARγ, AMPK, UCP-1, and FASN. Comparisons were made with control groups and standards like berberine and insulin. ResultsThe hydroalcoholic extracts (50:50 and 75:25) significantly enhanced glucose uptake (p < 0.001) and GLUT4 translocation, similar to the effects of insulin (p < 0.0001) and berberine (p < 0.0001). These extracts also upregulated p-AMPK (p < 0.0001) and UCP-1 expression (7.621), indicating improved insulin sensitivity and thermogenic activity. Additionally, these extracts differentially regulated PPARγ and FASN, suggesting a complex interaction with lipid metabolism. Notably, FASN expression was highly upregulated in water extract (37.792), indicating potential implications for fatty acid synthesis and storage. DiscussionLentinula edodes shows significant potential as a functional food for managing obesity and diabetes, supporting traditional TCM practices with modern scientific evidence. The study suggests that L. edodes can modulate key metabolic pathways such as glucose uptake, AMPK signalling, PPARγ regulation, and upregulation of FASN and UCP-1, making it a promising natural therapeutic agent. Further research, including clinical trials, is necessary to confirm these benefits in humans and explore the underlying mechanisms.

(Pro)renin receptor aggravates myocardial pyroptosis in diabetic cardiomyopathy through AMPK-NLRP3 pathway

IntroductionAs one of the most common complications of diabetes, diabetic cardiomyopathy (DCM) is the main cause of heart failure in patients with diabetes. However, the lack of effective treatments for DCM remains a clinical challenge. (Pro) renin receptor (PRR) is a member of renin angiotensin aldosterone system (RAAS). Here, we aim to determine whether PRR is involved in myocardial pyroptosis in diabetic cardiomyopathy.MethodsWe established diabetic rats model by intraperitoneal injection of streptozotocin (STZ). PRR overexpression adenovirus or PRR knockdown adenovirus was injected into the tail vein. Western blot, histopathology and immunohistochemistry staining, ELISA and Echocardiography were used to detect cardiac function changes and myocardial injury levels of DCM rats. Primary cardiomyocytes were stimulated with high glucose and PRR overexpression or PRR knockdown was achieved by adenovirus transfection, we also used the inhibitor of AMPK to decrease the activity of AMPK. Western blot, Real-time PCR, Immunofluorescence and ELISA were used to detect the level of PRR and pyroptosis in cardiomyocyte.ResultsWe found that high glucose increased the expression of PRR in heart. After overexpression of PRR, the expression of the pyroptosis related proteins such as Caspase-1, IL-1β, IL-18, and NLRP3 was significantly increased, the phosphorylation level of AMPK was significantly decreased, and the fibrosis level was significantly increased, thus aggravating the cardiac function injury of DCM. On the contrary, PRR knockdown can alleviate the level of myocardial pyroptosis in DCM and improve cardiac function. The related mechanism was that PRR could inhibit AMPK phosphorylation and promote the activation of NLRP3 inflammasome.DiscussionPRR aggravated pyroptosis of cardiomyocyte, increased the dysfunction of cardiomyocyte, and may be related to the decrease of AMPK phosphorylation and the overactivation of NLRP3. This may provide new ideas and targets for the treatment of DCM.

Sex differences in the expression of metabolic and pro-inflammatory markers in the initial post-COVID-19 phase

Abstract Cardiovascular complications are a common manifestation of post-acute COVID-19 infection. Post-COVID-19 syndrome is often associated with the female sex and exacerbated inflammation; however, the underlying molecular mechanisms of this sex difference remain poorly understood. In the present study, we aimed to investigate several metabolic, mitochondrial, autophagy, oxidative stress, and inflammatory markers in peripheral blood mononuclear cells (PBMCs) and plasma isolated from older (&amp;gt;75) male and female patients at the initial phase (1-2 weeks) after COVID-19 pneumonia. Age-matched non-infected women and men were used as a control group. We found a significantly higher plasma TNF-α in post-COVID-19 women, but not in men, compared to the control group. Similarly, a significant elevation of IL-1β and IL-18 mRNA in PBMCs from post-COVID-19 women, but not men, was observed. These effects were associated with marked activation of AMPK (defined as pAMPK/AMPK ratio), suggesting potential metabolic stress in female post-COVID-19 PBMCs. Further analysis revealed increased expression of mitochondrial genes, which may be due to AMPK activation as a compensatory reaction to metabolic stress. Analysis of autophagy or oxidative stress (serum 8-OHdG) markers did not reveal any differences between the groups investigated. We conclude that women in the initial phase of post-COVID-19 have elevated expression of inflammatory markers in plasma and in immune cells, which is associated with metabolic stress. This may contribute to the cardiovascular complications in female post-COVID-19 patients.

Alkaline Mineral Complex Water Attenuates Transportation-Induced Hepatic Lipid Metabolism Dysregulation by AMPKα-SREBP-1c/PPARα Pathways

Transportation, an unavoidable process in livestock farming, causes metabolic disorders in the body, which then lead to endocrine disruption, being immunocompromised, and growth suppression. Lipid metabolism dysregulation is a critical phenotype induced by transportation. The liver is a vital organ in lipid metabolism, with a role in both lipid synthesis and lipolysis. However, the specific mechanisms by which transportation affects hepatic lipid metabolism remain unclear. This study employed rats as a model to investigate the effects of transportation on hepatic lipid metabolism. Rats subjected to transportation showed altered serum lipid profiles, including decreased serum triglyceride (TG), low-density lipoprotein cholesterol (VLDL-C), and non-esterified fatty acid (NEFA) immediately after transportation (IAT) and serum total cholesterol (TC) on day 3, and increasing serum TG, TC, and low-density lipoprotein cholesterol (LDL-C) on day 10. Meanwhile, fatty droplets in the liver were also reduced at IAT and increased on days 3 and 10. Notably, transportation also affected hepatic-lipid-metabolism-related enzyme activities and signaling pathways, such as increased AMP-activated protein kinase alpha (AMPKα) phosphorylation and modulations in key proteins and genes related to lipid metabolism, decreased hepatic acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) activities at IAT, and increased carnitine palmitoyl transferase 1 alpha (CPT-1α) at IAT and ACC and CPT-1α activities on days 3 and 10. Supplementation with alkaline mineral complex water (AMC) before and after transportation mitigated the adverse effects on hepatic lipid metabolism by modulating the AMPKα-SREBP-1c/PPARα pathway, enhancing lipid synthesis, and reducing the oxidative catabolism of fatty acids. AMC inhibited the transportation-induced activation of AMPKα and restored the balance of lipid-metabolism-related enzymes and pathways. These findings highlight AMC’s potential as a therapeutic intervention to alleviate transportation-induced lipid metabolism disorders, offering significant implications for improving animal welfare and reducing economic losses in livestock farming.

Acquisition of neurodegenerative features in isogenic OPTN(E50K) human stem cell-derived retinal ganglion cells associated with autophagy disruption and mTORC1 signaling reduction

The ability to derive retinal ganglion cells (RGCs) from human pluripotent stem cells (hPSCs) has led to numerous advances in the field of retinal research, with great potential for the use of hPSC-derived RGCs for studies of human retinal development, in vitro disease modeling, drug discovery, as well as their potential use for cell replacement therapeutics. Of all these possibilities, the use of hPSC-derived RGCs as a human-relevant platform for in vitro disease modeling has received the greatest attention, due to the translational relevance as well as the immediacy with which results may be obtained compared to more complex applications like cell replacement. While several studies to date have focused upon the use of hPSC-derived RGCs with genetic variants associated with glaucoma or other optic neuropathies, many of these have largely described cellular phenotypes with only limited advancement into exploring dysfunctional cellular pathways as a consequence of the disease-associated gene variants. Thus, to further advance this field of research, in the current study we leveraged an isogenic hPSC model with a glaucoma-associated mutation in the Optineurin (OPTN) protein, which plays a prominent role in autophagy. We identified an impairment of autophagic-lysosomal degradation and decreased mTORC1 signaling via activation of the stress sensor AMPK, along with subsequent neurodegeneration in OPTN(E50K) RGCs differentiated from hPSCs, and have further validated some of these findings in a mouse model of ocular hypertension. Pharmacological inhibition of mTORC1 in hPSC-derived RGCs recapitulated disease-related neurodegenerative phenotypes in otherwise healthy RGCs, while the mTOR-independent induction of autophagy reduced protein accumulation and restored neurite outgrowth in diseased OPTN(E50K) RGCs. Taken together, these results highlighted that autophagy disruption resulted in increased autophagic demand which was associated with downregulated signaling through mTORC1, contributing to the degeneration of RGCs.

Aged Gut Microbiome Induces Metabolic Impairment and Hallmarks of Vascular and Intestinal Aging in Young Mice.

Aging, an independent risk factor for cardiometabolic diseases, refers to a progressive deterioration in physiological function, characterized by 12 established hallmarks. Vascular aging is driven by endothelial dysfunction, telomere dysfunction, oxidative stress, and vascular inflammation. This study investigated whether aged gut microbiome promotes vascular aging and metabolic impairment. Fecal microbiome transfer (FMT) was conducted from aged (>75 weeks old) to young C57BL/6 mice (8 weeks old) for 6 weeks. Wire myography was used to evaluate endothelial function in aortas and mesenteric arteries. ROS levels were measured by dihydroethidium (DHE) staining and lucigenin-enhanced chemiluminescence. Vascular and intestinal telomere function, in terms of relative telomere length, telomerase reverse transcriptase expression and telomerase activity, were measured. Systemic inflammation, endotoxemia and intestinal integrity of mice were assessed. Gut microbiome profiles were studied by 16S rRNA sequencing. Some middle-aged mice (40-42 weeks old) were subjected to chronic metformin treatment and exercise training for 4 weeks to evaluate their anti-aging benefits. Six-week FMT impaired glucose homeostasis and caused vascular dysfunction in aortas and mesenteric arteries in young mice. FMT triggered vascular inflammation and oxidative stress, along with declined telomerase activity and shorter telomere length in aortas. Additionally, FMT impaired intestinal integrity, and triggered AMPK inactivation and telomere dysfunction in intestines, potentially attributed to the altered gut microbial profiles. Metformin treatment and moderate exercise improved integrity, AMPK activation and telomere function in mouse intestines. Our data highlight aged microbiome as a mechanism that accelerates intestinal and vascular aging, suggesting the gut-vascular connection as a potential intervention target against cardiovascular aging and complications.

Myeloid Cell-Specific Deletion of AMPKα1 Worsens Ocular Bacterial Infection by Skewing Macrophage Phenotypes.

AMP-activated protein kinase (AMPK) plays a crucial role in governing essential cellular functions such as growth, proliferation, and survival. Previously, we observed increased vulnerability to bacterial (Staphylococcus aureus) endophthalmitis in global AMPKα1 knockout mice. In this study, we investigated the specific involvement of AMPKα1 in myeloid cells using LysMCre;AMPKα1fl mice. Our findings revealed that whereas endophthalmitis resolved in wild-type C57BL/6 mice, the severity of the disease progressively worsened in AMPKα1-deficient mice over time. Moreover, the intraocular bacterial load and inflammatory mediators (e.g., IL-1β, TNF-α, IL-6, and CXCL2) were markedly elevated in the LysMCre;AMPKα1fl mice. Mechanistically, the deletion of AMPKα1 in myeloid cells skewed macrophage polarization toward the inflammatory M1 phenotype and impaired the phagocytic clearance of S. aureus by macrophages. Notably, transferring AMPK-competent bone marrow from wild-type mice to AMPKα1 knockout mice preserved retinal function and mitigated the severity of endophthalmitis. Overall, our study underscores the role of myeloid-specific AMPKα1 in promoting the resolution of inflammation in the eye during bacterial infection. Hence, therapeutic strategies aimed at restoring or enhancing AMPKα1 activity could improve visual outcomes in endophthalmitis and other ocular infections.

Alcohol induces p53-mediated apoptosis in neural crest by stimulating an AMPK-mediated suppression of TORC1, S6K, and ribosomal biogenesis.

Prenatal alcohol exposure is a leading cause of permanent neurodevelopmental disability and can feature distinctive craniofacial deficits that partly originate from the apoptotic deletion of craniofacial progenitors, a stem cell lineage called the neural crest (NC). We recently demonstrated that alcohol causes nucleolar stress in NC through its suppression of ribosome biogenesis (RBG) and this suppression is causative in their p53/MDM2-mediated apoptosis. Here, we show that this nucleolar stress originates from alcohol's activation of AMPK, which suppresses TORC1 and the p70/S6K-mediated stimulation of RBG. Alcohol-exposed cells of the pluripotent, primary cranial NC line O9-1 were evaluated with respect to their S6K, TORC1, and AMPK activity. The functional impact of these signals with respect to RBG, p53, and apoptosis were assessed using gain-of-function constructs and small molecule mediators. Alcohol rapidly (<2hr) increased pAMPK, pTSC2, and pRaptor, and reduced both total and pS6K in NC cells. These changes persisted for at least 12hr to 18hr following alcohol exposure. Attenuation of these signals via gain- or loss-of-function approaches that targeted AMPK, S6K, or TORC1 prevented alcohol's suppression of rRNA synthesis and the induction of p53-stimulated apoptosis. We conclude that alcohol induces ribosome dysbiogenesis and activates their p53/MDM2-mediated apoptosis via its activation of pAMPK, which in turn activates TSC2 and Raptor to suppress the TORC1/S6K-mediated promotion of ribosome biogenesis. This represents a novel mechanism underlying alcohol's neurotoxicity and is consistent with findings that TORC1/S6K networks are critical for cranial NC survival.

The Role of Human Adiponectin Receptor 1 in 2-Ethylhexyl Diphenyl Phosphate Induced Lipid Metabolic Disruption.

Epidemiological evidence links exposure to 2-ethylhexyl diphenyl phosphate (EHDPP) with lipid metabolic disruption, typically attributed to nuclear receptors, while the role of membrane receptors remains underexplored. This study explored the role of adiponectin receptor 1 (AdipoR1) in EHDPP-induced lipid metabolic disturbances. We examined EHDPP's binding affinity and transcriptional impact on AdipoR1. AdipoR1 knockdown (AdipoR1kd) human liver cells and coculture experiments with AdipoR1 activator (AdipoRon) were used to investigate the effect and the mechanism. EHDPP disrupted triglyceride and phospholipid synthesis and altered corresponding gene expression, mirroring effects in AdipoR1kd cells but diminishing in EHDPP-treated AdipoR1kd cells. RNA sequencing revealed that EHDPP primarily disrupted oxidative phosphorylation and insulin signaling dependent on AdipoR1. Mechanistically, EHDPP interacted with AdipoR1 and reduced AdipoR1 protein levels at 10-7 mol/L or higher, weakening the activation of the calmodulin dependent protein kinase β (CaMKKβ)/AMPK/acetyl CoA carboxylase pathway. Furthermore, EHDPP pretreatment blocked the increase in Ca2+ flux and the corresponding kinase CaMKKβ, as well as liver kinase B1 (LKB1) activation induced by AdipoRon, which is necessary for AMPK activation. Collectively, these findings demonstrate that EHDPP-induced lipid imbalance is partially dependent on AdipoR1, expanding the understanding of environmental metabolic disruptors beyond nuclear receptors.

Complement factor B inhibitor LNP023 mediates the effect and mechanism of AMPK/mTOR on autophagy and oxidative stress in lupus nephritis.

This study investigated the impact of LNP023 on the AMPK/mTOR signaling pathway in lupus nephritis (LN) and its effects on autophagy and oxidative stress. A mouse model of LN was established, and renal injury was confirmed by assessing various LN markers, including antinuclear antibody, ds-DNA, anti-Sm antibody, and others. Mice were treated with LNP023, the AMPK activator AICAR, or the AMPK inhibitor dorsomorphin. Renal injury and fibrosis were evaluated using HE and Masson staining. Expression levels of AMPK, mTOR, LC3, Beclin1, and p62 were assessed by immunohistochemistry and Western blot. Oxidative stress and inflammatory markers were measured by polymerase chain reaction and enzyme-linked immunosorbent assay. LN mice exhibited low AMPK/p-AMPK and high mTOR/p-mTOR levels, alongside significant renal injury, fibrosis, reduced autophagy, and elevated oxidative stress. LNP023 treatment improved these parameters, with enhanced effects when combined with AICAR. Conversely, dorsomorphin reversed LNP023's therapeutic benefits. The complement factor B inhibitor LNP023 promotes kidney health in LN mice by mediating the AMPK/mTOR pathway, promoting autophagy, and attenuating oxidative stress.

A novel ER stress regulator ARL6IP5 induces reticulophagy to ameliorate the prion burden

ABSTRACT Prion disease is a fatal and infectious neurodegenerative disorder caused by the trans-conformation conversion of PRNP/PrPC to PRNP/PrPSc. Accumulated PRNP/PrPSc-induced ER stress causes chronic unfolded protein response (UPR) activation, which is one of the fundamental steps in prion disease progression. However, the role of various ER-resident proteins in prion-induced ER stress is elusive. This study demonstrated that ARL6IP5 is compensatory upregulated in response to chronically activated UPR in the cellular prion disease model (RML-ScN2a). Furthermore, overexpression of ARL6IP5 overcomes ER stress by lowering the expression of chronically activated UPR pathway proteins. We discovered that ARL6IP5 induces reticulophagy to reduce the PRNP/PrPSc burden by releasing ER stress. Conversely, the knockdown of ARL6IP5 leads to inefficient macroautophagic/autophagic flux and elevated PRNP/PrPSc burden. Our study also uncovered that ARL6IP5-induced reticulophagy depends on Ca2+-mediated AMPK activation and can induce 3 MA-inhibited autophagic flux. The detailed mechanistic study revealed that ARL6IP5-induced reticulophagy involves interaction with soluble reticulophagy receptor CALCOCO1 and lysosomal marker LAMP1, leading to degradation in lysosomes. Here, we delineate the role of ARL6IP5 as a novel ER stress regulator and reticulophagy inducer that can effectively reduce the misfolded PRNP/PrPSc burden. Our research opens up a new avenue of selective autophagy in prion disease and represents a potential therapeutic target.

Preventive Effect of 3,3'-dimethoxy-4,4'-dihydroxy-stilbene Triazole on Pulmonary Fibrosis through Inhibition of Inflammation and Down-regulation of TGF-b Signaling Pathway.

In the present study effect of 3,3'-dimethoxy-4,4'-dihydroxy-stilbene triazole (STT) on plmonary fibrosis development was investigated in vitro in primary lung fibroblasts as well as in vivo in mice model. The results demonstrated that STT treatment effectively inhibited the TGF-β1 induced increase in expression of α-SMA and collagen I proteins in PLFs. STT treatment effectively reversed the TGF-β1 induced increase in expression of LOXL2 protein and phosphorylation of Smad2/3 proteins. Treatment of PLFs with STT reversed the TGF-β1-induced increase in expression of NOX4 and suppression of p-AMPK protein. In mice model of pulmonary fibrosis STT treatment significantly inhibited the BLM-mediated decrease in body weight and survival rate. The BLM induced increase in pulmonary index in mice was also effectively inhibited on treatment with STT. Treatment of the mice with STT inhibited the BLM-induced increase in α-SMA and Col I protein expression in pulmonary tissues. The BLM-induced increase in TGF-β1 protein expression in pulmonary tissues of the mice was inhibited on treatment with STT. Treatment with STT effectively promoted the AMPK activation in lung tissues of the BLM administered mice. In summary, the present study demonstrates that STT treatment prevents TGF-β1 induced up-regulation of α-SMA, collagen I, LOXL2 protein expression and targets phosphorylation of Smad2/3 proteins in PLFs. Moreover, it inhibits TGF-β1-induced increase in expression of NOX4 and reverses TGF-β1-mediated suppression in expression of p-AMPK protein. Therefore, STT inhibits fibrosis development in vitro as well as in vivo and therefore can be investigated further as a therapeutic agent for the treatment of lung fibrosis.

Lactiplantibacillus plantarum P101 Alleviated Alcohol-Induced Hepatic Lipid Accumulation in Mice via AMPK Signaling Pathway: Gut Microbiota and Metabolomics Analysis.

Mitigating steatosis is essential for delaying the progression of alcoholic liver disease. The effect and mechanism of Lactiplantibacillus plantarum P101 (LP.P101) on alleviating alcohol-induced hepatic lipid accumulation were investigated in our study. The mouse model was constructed by a short-term (10-day)-plus-binge ethanol feeding and gavaged with 108 CFU/mL of LP.P101 daily. Lipid droplet in the liver was significantly reduced by LP.101 intervention on AMPK activation. However, when AMPK was inhibited by dorsomorphin, the levels of related indicators (ALT, TG, etc.) and the expression levels of AMPK and relevant genes in the liver converged to that of the alcohol-fed group. Compared with the alcohol-fed group, LP.P101 reduced the relative abundance of Firmicutes and increased that of Bacteroidetes. Parabacteroides merdae was negatively correlated with lipid accumulation, and unclassified Negativibacillus was negatively associated with AMPK activation. Importantly, LP.P101 modified the compositions of the serum metabolites. The potential biomarker stercobilinogen was positively correlated with AMPK activation and negatively associated with lipid accumulation. This work confirmed that LP.P101 attenuated alcohol-induced hepatic lipid accumulation in mice through AMPK activation, and the alterations in gut microbiota and metabolites may play a significant role on AMPK activation.

Metabolic Side Effects from Antipsychotic Treatment with Clozapine Linked to Aryl Hydrocarbon Receptor (AhR) Activation.

Metabolic syndrome (MetS) is the most common adverse drug reaction from psychiatric pharmacotherapy. Neuroreceptor blockade by the antipsychotic drug clozapine induces MetS in about 30% of patients. Similar to insulin resistance, clozapine impedes Akt kinase activation, leading to intracellular glucose and glutathione depletion. Additional cystine shortage triggers tryptophan degradation to kynurenine, which is a well-known AhR ligand. Ligand-bound AhR downregulates the intracellular iron pool, thereby increasing the risk of mitochondrial dysfunction. Scavenging iron stabilizes the transcription factor HIF-1, which shifts the metabolism toward transient glycolysis. Furthermore, the AhR inhibits AMPK activation, leading to obesity and liver steatosis. Increasing glucose uptake by AMPK activation prevents dyslipidemia and liver damage and, therefore, reduces the risk of MetS. In line with the in vitro results, feeding experiments with rats revealed a disturbed glucose-/lipid-/iron-metabolism from clozapine treatment with hyperglycemia and hepatic iron deposits in female rats and steatosis and anemia in male animals. Decreased energy expenditure from clozapine treatment seems to be the cause of the fast weight gain in the first weeks of treatment. In patients, this weight gain due to neuroleptic treatment correlates with an improvement in psychotic syndromes and can even be used to anticipate the therapeutic effect of the treatment.

Drp1 acetylation mediated by CDK5-AMPK-GCN5L1 axis promotes cerebral ischemic injury via facilitating mitochondrial fission

The aberrant acetylation of mitochondrial proteins is involved in the pathogenesis of multiple diseases including neurodegenerative diseases and cerebral ischemic injury. Previous studies have shown that depletion of mitochondrial NAD+, which is necessary for mitochondrial deacetylase activity, leads to decreased activity of mitochondrial deacetylase and thus causes hyperacetylation of mitochondrial proteins in ischemic brain tissues, which results in altered mitochondrial dynamics. However, it remains largely unknown about how mitochondrial dynamics-related protein Drp1 is acetylated in ischemic neuronal cells and brain tissues. Here, we showed that Drp1 and GCN5L1 expression was up-regulated in OGD-treated neuronal cells and ischemic brain tissues induced by dMCAO, accompanied by the increased mitochondrial fission, mtROS accumulation, and cell apoptosis. Further, we confirmed that ischemia/hypoxia promoted Drp1 interaction with GCN5L1 in neuronal cells and brain tissues. GCN5L1 knockdown attenuated, while its overexpression enhanced Drp1 acetylation and mitochondrial fission, indicating that GCN5L1 plays a crucial role in ischemia/hypoxia-induced mitochondrial fission by acetylating Drp1. Mechanistically, ischemia/hypoxia induced Drp1 phosphorylation by CDK5 upregulation-mediated activation of AMPK in neuronal cells, which in turn facilitated the interaction of GCN5L1 with Drp1, thus enhancing Drp1 acetylation and mitochondrial fission. Accordingly, inhibition of AMPK alleviated ischemia/hypoxia- induced Drp1 acetylation and mitochondrial fission and protected brain tissues from ischemic damage. These findings provide a novel insight into the functional roles of GCN5L1 in regulating Drp1 acetylation and identify a previously unrecognized CDK5-AMPK-GCN5L1 pathway that mediates the acetylation of Drp1 in ischemic brain tissues.