Adenosine Monophosphate-activated Protein Kinase Activation Research Articles

Current and Evolving Concepts in the Management of Complex Regional Pain Syndrome: A Narrative Review

Background/Objectives: Complex regional pain syndrome (CRPS) is characterized by severe pain and reduced functionality, which can significantly affect an individual’s quality of life. The current treatment of CRPS is challenging. However, recent advances in diagnostic and treatment methods show promise for improving patient outcomes. This review aims to place the question of CRPS in a broader context and highlight the objectives of the research for future directions in the management of CRPS. Methods: This study involved a comprehensive literature review. Results: Research has identified three primary pathophysiological pathways that may explain the clinical variability observed in CRPS: inflammatory mechanisms, vasomotor dysfunction, and maladaptive neuroplasticity. Investigations into these pathways have spurred the development of novel diagnostic and treatment strategies focused on N-Methyl-D-aspartate Receptor Antagonists (NMDA), Toll-like receptor 4 (TLR-4), α1 and α2 adrenoreceptors, as well as the identification of microRNA (miRNA) biomarkers. Treatment methods being explored include immune and glial-modulating agents, intravenous immunoglobulin (IVIG) therapy, plasma exchange therapy, and neuromodulation techniques. Additionally, there is ongoing debate regarding the efficacy of other treatments, such as free radical scavengers, alpha-lipoic acid (ALA), dimethyl fumarate (DMF), adenosine monophosphate-activated protein kinase (AMPK) activators such as metformin, and phosphodiesterase-5 inhibitors such as tadalafil. Conclusions: The controversies surrounding the mechanisms, diagnosis, and treatment of CRPS have prompted researchers to investigate new approaches aimed at enhancing understanding and management of the condition, with the goal of alleviating symptoms and reducing associated disabilities.

Use of metformin in treatment of dengue fever

Dear Editor, Dengue Fever is the fastest spreading mosquito-borne viral disease globally, affecting greater than 100 million humans annually. Dengue also causes 20 to 25,000 deaths, primarily in children, and is found in more than 100 countries. Although most cases are asymptomatic, severe illness and death may occur. (1) According to the WHO, between 1st January to 27th September 2022, the National Institute of Health-Islamabad reported 25,932 confirmed dengue cases and 62 deaths nationwide (2). 74% of these cases were reported during September alone. Of these, 32% were from Sindh, 29% from Punjab (including the Islamabad Capital Territory), 25% from Khyber Pakhtunkhwa (5506), and 14% from Balochistan (2). The current treatment for dengue fever doesn't involve direct medication. Instead, the focus is on symptomatic treatment. Initial steps focus on bed rest and increased fluid intake to combat dehydration caused by vomiting. In severe cases, hospitalization for supportive care becomes necessary. Patients are monitored for dehydration and electrolyte balance, platelet counts, and blood pressure, with interventions such as transfusions if needed (3). New and improved treatments for dengue are being explored worldwide. One of these emerging treatments is the efficacy of metformin in dengue treatment. A study published in 2018 showed that diabetic dengue patients who were metformin users were 33-40% less likely to develop severe dengue- according to WHO 2009 dengue criteria- than those who were not. (4) From the metformin users 28.2% progressed to severe dengue whereas from the non-metformin users 42.4% progressed to severe dengue. The same study showed that metformin users had a significantly lower instance of severe bleeding than non-users. In obese patients the enzyme Adenosine Monophosphate (AMP) – Activated protein kinase (AMPK) is down regulated. Its down regulation results in the inhibition of lipid catabolism and increased de novo lipid synthesis, which are favourable conditions for viral replication and survival within host cells (5). The hypoglycaemic agent metformin –dymethybiguanide- controls glucose metabolism via activation of AMPK. Hence obese patients with dengue could benefit from it. Bearing in mind the rising cases of dengue in Pakistan, we suggest that the possibility of an improved treatment with metformin, especially in obese patients, should be explored in the country. Metformin is cheap (locally priced at 35 rupees, brand name Glucophage), easy to administer and does not have any major side effects. ---Continue

IP6K1 rewires LKB1 signaling to mediate hyperglycemic endothelial senescence.

Diabetes is a major risk factor for cardiovascular disease, but the molecular mechanisms underlying diabetic vasculopathy have been elusive. Here we report that inositol hexakisphosphate kinase 1 (IP6K1) mediates hyperglycemia-induced endothelial senescence by rewiring the liver kinase B1 (LKB1) signaling from activating the adenosine monophosphate-activated protein kinase (AMPK) pathway to the p53 pathway. We found that hyperglycemia upregulated IP6K1, which disrupts the Hsp/Hsc70 and carboxyl terminus of Hsc70-interacting protein (CHIP)-mediated LKB1 degradation, leading to increased expression levels of LKB1. High glucose also strengthens the binding of IP6K1 to AMPK, suppressing the LKB1-mediated AMPK activation. Thus, the elevated LKB1 does not lead to the activation of the AMPK pathway. Instead, it binds more to p53, resulting in p53-dependent endothelial senescence. Endothelial-specific deletion of IP6K1 alleviates, whereas endothelial-specific overexpression of IP6K1 exaggerates the hyperglycemia-induced endothelial senescence. This study reveals a regulatory mechanism of IP6K1 in switching the LKB1/AMPK pathway to LKB1/p53 pathway. IP6K1 represents a potential therapeutic target for treating hyperglycemia-induced endothelial dysfunction.

GENI as an AMPK Activator Binds α and γ Subunits and Improves the Memory Dysfunction of Alzheimer's Disease Mouse Models via Autophagy and Neuroprotection.

Geniposidic 4-isoamyl ester (GENI) with anti-aging effects is a new iridoid glycoside derivative from Gardenia jasminoides Ellis found in our previous study. In this study, to indicate whether this compound has anti-Alzheimer's disease (AD) effect, the galactose-induced AD mice and naturally aging mice with AD were used to do drug efficacy evaluation. Furthermore, the Western blot, small interfering RNA (siRNA), drug affinity responsive target stability (DARTS), cellular thermal shift assay (CESTA), liquid chromatography-tandem mass spectrometry (LC/MS-MS), adenosine 5'-monophosphate-activated protein kinase (AMPK) mutants and surface plasmon resonance (SPR) analysis were utilized to clarify the mechanism of action and identify target protein of this molecule. GENI exerts anti-AD efficacy in galactose-induced AD mice and naturally aging mice with AD through neuroprotection and modification of autophagy and neuron inflammation. Moreover, AMPK as the target protein of GENI to produce an anti-AD effect is identified and the ASP148, ASP157, and ASP166 of the AMPK α subunit and lysine (LYS)148, aspartic acid (ASP)156, LYS309, and ASP316 in the AMPK γ subunit as binding sites are confirmed. Meanwhile, the AMPK/unc-51-like autophagy-activating kinase 1 (ULK1)/microtubule-associated protein 1 light chain 3 beta (LC3B) and AMPK/mammalian target of rapamycin (mTOR) signaling pathways involved in anti-AD effects of GENI. The findings provide a new perspective on treating neurodegenerative diseases by activating AMPK for the energy metabolism disorder.

Salinity stress impairs disease resistance in white shrimp, Penaeus vannamei through AMPK pathway, ameliorated by dietary glucose-mediated energy homeostasis.

This study presents a comprehensive examination of the physiological adaptations of white shrimp (Penaeus vannamei) to low-salinity conditions and evaluates the effects of supplementing dietary glucose on disease resistance. Compared to the control group, shrimp cultured at a salinity of 4psu exhibit significantly elevated expression levels of adenosine 5'-monophosphate-activated protein kinase (AMPK) in the hepatopancreas, which leads to increased energy expenditure and a corresponding reduction in resistance to infection by Vibrio alginolyticus. The suppression of AMPK via dsAMPK treatment markedly enhances disease resistance. Moreover, shrimp raised in low salinity conditions exhibit downregulation of mTOR-associated molecules, including Lipin-1 and hypoxia-inducible factor 1-α (HIF-1α), both of which are essential for immune regulation. Metabolic assessments revealed reduced ATP levels and disrupted ATP/AMP and ATP/ADP ratios, indicating energy imbalance under low salinity stress. Notably, supplementing the diet with 1% glucose significantly increased glycogen reserves and ATP content, stabilized hemolymph glucose levels, and upregulated glycolysis-related genes, thereby optimizing energy metabolism and enhancing resilience to stress. This study underscores that AMPK activation in response to low salinity conditions leads to increased energy expenditure, which in turn lowers disease resistance. Furthermore, it underscores the critical role of strategic dietary management in maintaining energy homeostasis and improving disease resistance in white shrimp under stressful environmental conditions associated with climate change, offering valuable insights for aquaculture nutrition strategies.

The role of AMPK activation in metabolic regulation, energy homeostasis and aging: A comprehensive overview

5’ Adenosine monophosphate-activated protein kinase (AMPK) is a metabolic sensor responsible for maintaining homeostasis, regulating metabolic control, monitoring energy status, and balancing energy production with consumption. The most important protein kinases that activate AMPK are liver kinase B1 and calcium-calmodulin-dependent protein kinase. AMPK significantly impacts physical performance by accelerating recovery periods and restoring energy stores through several key mechanisms. It regulates muscle glycogen content, ensuring readily available energy during physical exertion. In addition, a high number of mitochondria enable the utilization of fatty acids as an energy source, thereby improving endurance efforts. Furthermore, rich vascularization in the muscles enhances the delivery of nutrients and oxygen, optimizing performance and speeding up recovery. AMPK is also important for maintaining muscle homeostasis. It decreases insulin resistance, stimulates mitochondrial biogenesis, and exerts an antioxidant effect. As a regulator of energy homeostasis, AMPK plays a key role in linking cellular energy levels with the aging process. It acts as a modulator of cellular senescence and has the potential to extend life expectancy, particularly in the context of caloric restriction. By activating AMPK, caloric restriction (activated with a 30 – 70% reduction in nutrient intake) helps to maintain energy balance in cells, which may slow down aging and support healthier cellular function over time. In conclusion, the involvement of AMPK in metabolic regulation and maintenance makes it an important therapeutic target for the treatment and prevention of several diseases, both age-related and otherwise.

Orchestrated desaturation reprogramming from stearoyl-CoA desaturase to fatty acid desaturase 2 in cancer epithelial-mesenchymal transition and metastasis.

Adaptative desaturation in fatty acid (FA) is an emerging hallmark of cancer metabolic plasticity. Desaturases such as stearoyl-CoA desaturase (SCD) and fatty acid desaturase 2 (FADS2) have been implicated in multiple cancers, and their dominant and compensatory effects have recently been highlighted. However, how tumors initiate and sustain their self-sufficient FA desaturation to maintain phenotypic transition remains elusive. This study aimed to explore the molecular orchestration of SCD and FADS2 and their specific reprogramming mechanisms in response to cancer progression. The potential interactions between SCD and FADS2 were explored by bioinformatics analyses across multiple cancer cohorts, which guided subsequent functional and mechanistic investigations. The expression levels of desaturases were investigated with online datasets and validated in both cancer tissues and cell lines. Specific desaturation activities were characterized through various isomer-resolved lipidomics methods and sensitivity assays using desaturase inhibitors. In-situ lipid profiling was conducted using multiplex stimulated Raman scattering imaging. Functional assays were performed both in vitro and in vivo, with RNA-sequencing employed for the mechanism verification. After integration of the RNA-protein-metabolite levels, the data revealed that a reprogramming from SCD-dependent to FADS2-dependent desaturation was linked to cancer epithelial-mesenchymal transition (EMT) and progression in both patients and cell lines. FADS2 overexpression and SCD suppression concurrently maintained EMT plasticity. A FADS2/β-catenin self-reinforcing feedback loop facilitated the degree of lipid unsaturation, membrane fluidity, metastatic potential and EMT signaling. Moreover, SCD inhibition triggered a lethal apoptosis but boosted survival plasticity by inducing EMT and enhancing FA uptake via adenosine monophosphate-activated protein kinase activation. Notably, this desaturation reprogramming increased transforming growth factor-β2, effectively sustaining aggressive phenotypes and metabolic plasticity during EMT. These findings revealed a metabolic reprogramming from SCD-dependent to FADS2-dependent desaturation during cancer EMT and progression, which concurrently supports EMT plasticity. Targeting desaturation reprogramming represents a potential vulnerability for cancer metabolic therapy.

Pharmacological Activation of AMPK Prevents Drp1-mediated Mitochondrial Fission and Alleviates Hepatic Steatosis In vitro.

The incidence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. Adenosine monophosphate-activated protein kinase (AMPK) activation is beneficial for NAFLD treatment. Recent studies show the excessive fission of mitochondria during NAFLD progression, so targeting mitochondria dynamics may be a possible target for NAFLD. Still, little is known about whether AMPK regulates mitochondrial dynamics in hepar. This study investigated whether AMPK activation alleviates hepatic steatosis by regulating mitochondrial dynamics mediated by GTPase dynamin-related protein 1 (Drp1). Human hepatocyte line L-02 cells were cultured and subjected to palmitic acid (PA) treatment for 24 h to establish a hepatic steatosis model in vitro, which was pre-treated with different tool drugs. Hepatocyte function, hepatocyte lipid content, mitochondrial reactive oxygen species (ROS) production, and mitochondrial membrane potential (MMP) were examined. The expression levels of genes and proteins associated with mitochondrial dynamics were assessed using reverse transcription-quantitative PCR and western blotting. The results indicated that 5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR), an AMPK activator, improved hepatocyte function, as demonstrated by decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity (P<0.05 or P<0.01). In addition, AICAR decreased total cholesterol (TC) and triglyceride (TG) content and lipid deposition in hepatocytes (P<0.01); decreased ROS production; improved MMP (P<0.01); reduced fission-1 (Fis1) and mitochondrial fission factor (Mff) mRNA expression; and downregulated p-Drp1 (Ser 616) protein expression. In contrast, AICAR increased mitochondrial fusion factor mitofusin-1 (Mfn1) and mitofusin-2 (Mfn2) mRNA expression and upregulated p-Drp1 (Ser 637) protein expression. Mdivi-1, a Drp-1 inhibitor, was used to confirm whether mitochondrial dynamics regulated by Drp1-mediated the role of AICAR. Similar to AICAR, Mdivi-1 improved hepatocyte function and MMP significantly, decreased ROS production and lipid deposition, downregulated Fis1 and Mff mRNA expression, downregulated p-Drp1 (Ser 616) protein expression, and enhanced Mfn1 and Mfn2 mRNA and p-Drp1 (Ser 637) protein expression. However, Compound C, an AMPKspecific inhibitor, had less impact on the protective effect of Mdivi-1. The results demonstrated that AMPK activation has a protective effect on hepatic steatosis in vitro, largely dependent on the inhibition of Drp1-mediated mitochondrial fission.

Investigating the effect of metformin on chemobrain: Reports from cells to bedside.

Chemobrain can be defined as the development of cognitive side effects following chemotherapy, which is increasingly reported in cancer survivor patients. Chemobrain leads to reduced patients' quality of life by causing different symptoms ranging from strokes and seizures to memory loss and mood disorders. Metformin, an antidiabetic drug, has been proposed as a potential treatment to improve the symptoms of chemotherapy-induced cognitive dysfunction. Several benefits of metformin on chemobrain have been suggested, including anti-inflammation, anti-oxidative stress, restoring impaired mitochondrial function, stabilizing apoptosis, ameliorating impairments to dendritic spine density, normalizing brain senescence protein levels, and attenuating reductions in cell viability, along with reversing learning and memory deficits. These benefits occur through various pathways of metformin, including adenosine monophosphate-activated protein kinase (AMPK), TAp73, and phosphatidylinositol 3-kinase/protein kinase B (Akt) pathways. In addition, metformin can exert neuroprotective effects and restore deficits in brain homeostasis caused by chemotherapy. Furthermore, activation of AMPK following metformin therapy promotes autophagy, stimulates energy production, and improves cell survival. Metformin's interaction with Tap73 and Akt pathways allows for regulated cell proliferation in adult neural precursor cells and cell growth, respectively. Although the negative effects on cerebral function induced by chemotherapeutics have been alleviated by metformin in several instances, further studies are required to confirm its beneficial effects. This research is essential as it addresses the pressing issue of chemobrain, which is on the rise alongside global increases in cancer. Exploring metformin's potential as a neuroprotective agent offers a promising avenue for mitigating these cognitive impairments and highlights the need for further studies to validate its therapeutic mechanisms. This review comprehensively summarises evidence from both in vitro and in vivo studies to demonstrate metformin's effects on cognitive function when co-administered with chemotherapy and identifies gaps in knowledge for further investigation.

Delphinidin induces a fast-to-slow muscle fiber type shift through the AMPK signaling pathway in C2C12 myotubes

Delphinidin, a plant anthocyanidin, suppresses disuse muscle atrophy in mice. However, its effect on muscle fiber type shift is unclear. To examine whether delphinidin affects skeletal muscle fiber type, differentiated C2C12 cells were treated with delphinidin. Results revealed that delphinidin upregulated the mRNA expression of myosin heavy chain type I (MyHCI), troponin C1, troponin I1, and MyHCIIx and increased slow MyHC protein level in C2C12 myotubes. Delphinidin also enhanced succinic dehydrogenase (SDH) activities and suppressed lactate dehydrogenase (LDH) activity. Adenosine monophosphate–activated protein kinase (AMPK) inhibition attenuated delphinidin-induced MyHCI upregulation and MyHCIIb downregulation. We investigated the effect of delphinidin on the upstream factors involved in AMPK activation. Delphinidin increased liver kinase B1 (LKB1) phosphorylation and nuclear respiratory factor 1 (NRF1) and calcium/calmodulin-dependent protein kinase 2 (CaMKK2) protein levels. In conclusion, delphinidin induced muscle fiber type conversion from fast-twitch to slow-twitch muscles through the AMPK signaling pathway.

Coptisine inhibits lipid accumulation in high glucose- and palmitic acid-induced HK-2 cells by regulating the AMPK/ACC/CPT-1 signaling pathway.

AMPK (Adenosine 5'-Monophosphate activated Protein Kinase) functions as a fundamental regulator of glycolipid metabolism by regulating the rate-limiting enzyme activity of ACC (Acetyl-CoA Carboxylase, essential for fatty acid biosynthesis) and CPT-1 (Carnitine palmitoyltransferase-1, essential for mitochondrial fatty acid oxidation, FAO) in cells, which is crucial for maintaining energy homeostasis in the human body. Coptisine (COP) is a natural berberine and isoquinoline alkaloid in Coptis chinensis that has been used as a traditional Chinese herb to treat diabetes for thousands of years, but its mechanism of action is still unclear. In this study, we investigated the anti-lipid accumulation effect and mechanism of COP in high glucose and palmitic acid-induced HK-2 cells. Compared with the control HK-2 cells, the model HK-2 cells exhibited markedly greater lipid deposition, after treatment with high glucose (HG, 30 mM) and palmitic acid (PA, 250 µM) for 24h. However, COP significantly decreased the TC and TG levels in a dose dependent manner (2.5, 5, and 10 µM). Moreover, COP dramatically enhanced the effect of the positive control (AICAR, Acadesine, an AMPK activator) in alleviating lipid deposition, which was reversed by the negative control (Compound C, an AMPK inhibitor). Furthermore, COP also increased p-AMPK, p-ACC and CPT-1 protein expression. Our results indicate that COP can effectively protects HK-2 cells against HG- and PA-induced lipid accumulation by affecting the AMPK/ACC/CPT-1 signaling pathway, inhibiting de novo lipogenesis and enhancing the FAO processes, which offers novel insights for the application of COP in the clinic.

L-aspartate ameliorates diet-induced obesity by increasing adipocyte energy expenditure.

Obesity always leads to profound perturbation of metabolome. Metabolome studies enrich the knowledge on associations between endogenous metabolites and obesity, potentially providing innovative strategies for the development of novel anti-obesity pharmacotherapy. This study aims to identify an endogenous metabolite that regulates energy expenditure and to explore its application for obesity treatment. C57BL/6 mice were fed with a high-fat and high-cholesterol (HFC) diet, comprising 60% fat and 1.2% cholesterol, for 12 weeks to induce obesity. Significant metabolites were identified in the livers of both health and obese mice through comparative hepatic metabolomics analysis. Correlation between serum or adipose L-aspartate level and body weight in obese mice, as well as human body mass index (BMI), was evaluated. In addition, saline or 200 mg/kg L-aspartate was orally administrated to HFC diet mice and HFC diet-induced obese mice for 6-7 weeks. Body weight, adipose tissue weight, glucose tolerance and liver damage were assessed to evaluate the effect on obesity prevention and treatment. Comprehensive lab animal monitoring system (CLAMS) and seahorse assay were employed to investigate the regulatory effect of L-aspartate on energy metabolism in vivo and in vitro, respectively. 3T3-L1 preadipocytes and murine white adipose tissue (WAT) were utilized to examine the impact of L-aspartate on adipocyte adipogenesis and lipogenesis and cellular signalling pathway in vitro and in vivo. L-aspartate, an approved drug for liver injury and chronic fatigue, was identified as an endogenous inducer of energy expenditure. Serum or adipose L-aspartate levels were found to be negatively correlated with the severity of obesity in both humans and mice. Administration of L-aspartate to HFC diet mice led to a significant reduction in body weight, with decreases of 14.5% in HFC diet mice and 8.5% in HFC diet-induced obese mice, respectively. In addition, the treatment improved related metabolic syndrome (Figure 2 and Figure S3). These therapeutics were associated with enhancements in whole-body energy expenditure and suppression of adipocyte adipogenesis along with activation of Adenosine 5'-monophosphate-activated protein kinase (AMPK) signalling pathway. L-aspartate may serve as a novel endogenous inducer of energy expenditure and suppressor of adipogenesis and lipogenesis along with activation of AMPK, thereby offering a promising therapeutic strategy for obesity prevention and treatment.

Exercise training attenuates cardiac dysfunction induced by excessive sympathetic activation through an AMPK-KLF4-FMO2 axis

Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide and are associated with an overactivated sympathetic system. Although exercise training has shown promise in mitigating sympathetic stress-induced cardiac remodeling, the precise mechanisms remain elusive. Here, we demonstrate that exercise significantly upregulates cardiac flavin-containing monooxygenase 2 (FMO2) expression. Notably, we find that exercise training effectively counteracts sympathetic overactivation-induced cardiac dysfunction and fibrosis by enhancing FMO2 expression via adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK) activation. Functional investigations employing FMO2 knockdown with adeno-associated virus 9 (AAV9) underscore the necessity for FMO2 expression to protect the heart during exercise in vivo. Furthermore, we identify the krüppel-like factor 4 (KLF4) as a transcriptional mediator of FMO2 that is crucial for the mechanism through which AMPK activation protects against sympathetic overactivation-induced cardiac dysfunction and fibrosis. Taken together, our study reveals a cardioprotective mechanism for exercise training through an AMPK-KLF4-FMO2 signaling pathway that underscores how exercise alleviates cardiac dysfunction induced by excessive sympathetic activation.

Salidroside alleviates high glucose and ethanol-induced pyroptosis in insulinoma cells

This study established a pyroptosis injury model by stimulating insulinoma cells(INS-1) of rats with high glucose(HG) and observed the impact of additional ethanol(ET) exposure on cell pyroptosis, as well as the intervention effect of salidroside(SAL). INS-1 cells were cultured and divided into a normal control group(NG), an HG group, an HG + ET(100 mmol·L~(-1)) group, and an HG + ET + SAL(1-100 μmol·L~(-1)) group. After 72 hours of treatment, cell viability was assessed using the cell counting kit-8(CCK-8) assay. The number of pyroptotic bodies was observed under a microscope. Western blot was used to detect changes in the intracellular Nod-like receptor protein 3(NLRP3)/gasdermin D(GSDMD) signaling pathway and adenosine monophosphate-activated protein kinase(AMPK) activity. A fluorescence probe was used to detect changes in intracellular reactive oxygen species(ROS) levels. Time-resolved fluorescence resonance energy transfer(TR-FRET) technology was employed to observe the effect of SAL on recombinant AMPK protein kinase activity in vitro. The results showed that compared to the NG group, HG exposure induced an increase in the number of pyroptotic bodies, elevated ROS levels, and activation of the NLRP3/GSDMD signaling pathway in INS-1 cells. Compared to the HG group, HG + ET exposure further exacerbated these changes. Compared to the HG + ET group, SAL dose-dependently increased cell viability, reduced the formation of pyroptotic bodies in INS-1 cells, and inhibited excessive ROS production, overactivation of the NLRP3/GSDMD signaling pathway, and the decrease in AMPK activity. TR-FRET experiments indicated that SAL could directly activate AMPK. When INS-1 cells were pretreated with an AMPK inhibitor, the effects of SAL on increasing cell viability, alleviating the formation of pyroptotic bodies, and inhibiting excessive ROS production were abolished. These results suggest that SAL can alleviate HG combined with ET-induced exacerbation of INS-1 pyroptosis by activating AMPK.

ULK1-regulated AMP sensing by AMPK and its application for the treatment of chronic kidney disease

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a central kinase involved in energy homeostasis. Increased intracellular AMP levels result in AMPK activation through the binding of AMP to the γ-subunit of AMPK. Recently, we reported that AMP-induced AMPK activation is impaired in the kidneys in chronic kidney disease (CKD) despite an increase in the AMP/ATP ratio. However, the mechanisms by which AMP sensing is disrupted in CKD are unclear. Here, we identified mechanisms of energy homeostasis in which Unc-51-like kinase 1 (ULK1)-dependent phosphorylation of AMPKγ1 at Ser260/Thr262 promoting AMP sensitivity of AMPK. AMPK activation by AMP was impaired in Ulk1 knockout mice despite an increased AMP/ATP ratio. ULK1 expression is markedly downregulated in CKD kidneys, leading to AMP sensing failure. Additionally, MK8722, an allosteric AMPK activator, stimulated AMPK in the kidneys of a CKD mouse model (5/6th nephrectomy) via a pathway that is independent of AMP sensing. Thus, our study shows that MK8722 treatment significantly attenuates the deterioration of kidney function in CKD and may be a potential therapeutic option in CKD therapeutics.

Suppression of hepatic steatosis in non-alcoholic steatohepatitis model by modified Xiaoyao San formula: Evidence, mechanisms and perspective.

In this letter, we comment on a recent publication by Mei et al, in the World Journal of Hepatology, investigating the hepatoprotective effects of the modified Xiaoyao San (MXS) formula in a male rat model of non-alcoholic steatohepatitis (NASH). The authors found that MXS treatment mitigated hepatic steatosis and inflammation in the NASH model, as evidenced by the reduction in lipid droplets (LDs), fibrosis markers and lipogenic factors. Interestingly, these hepatoprotective effects were associated with androgen upregulation (based on metabolomics analysis of male steroid hormone metabolites), adenosine 5'-monophosphate-activated protein kinase (AMPK) activation, and restoration of phosphatase and tensin homolog (PTEN) expression. However, the authors did not clearly discuss the relationships between MXS-induced hepatic steatosis reduction in the NASH model, and androgen upregulation, AMPK activation, and restoration of PTEN expression. This editorial emphasizes the reported mechanisms and explains how they act or interact with each other to reduce hepatic steatosis and inflammation in the NASH model. As a perspective, we propose additional mechanisms (such as autophagy/lipophagy activation in hepatocytes) for the clearance of LDs and suppression of hepatic steatosis by MXS in the NASH model. A proper understanding of the mechanisms of MXS-induced reduction of hepatic steatosis might help in the treatment of NASH and related diseases.

Regulation of Bacillus Calmette-Guérin-induced macrophage autophagy and apoptosis by the AMPK–mTOR–ULK1 pathway

Tuberculosis (TB) is a chronic wasting infectious disease caused by Mycobacterium tuberculosis (MTB) or Mycobacterium bovis that can be transmitted among people and domestic animals. During the development of TB, macrophages of the innate immune system can act against MTB via autophagy and apoptosis to prevent the spread of the disease. Among the many autophagy regulatory pathways, the adenosine monophosphate (AMP)–activated protein kinase (AMPK)–mammalian rapamycin target protein (mTOR)–Unc-51-like kinase 1 (ULK1) pathway has received considerable attention. This study investigates the regulatory role of the AMPK–mTOR–ULK1 pathway in attenuating M. bovis Bacillus Calmette–Guérin (BCG)-induced autophagy and apoptosis in murine monocyte macrophages (RAW264.7). Changes in macrophage autophagy and apoptosis were analyzed using the AMPK activator AICAR and inhibitor Compound C to interfere with the AMPK–mTOR–ULK1 pathway and siRNA to silence the pathway. Consequently, BCG stimulation of macrophages significantly activated the AMPK–mTOR–ULK1 pathway while BCG-induced macrophage AMPK activation promoted macrophage autophagy and apoptosis. Activation of the AMPK–mTOR–ULK1 pathway by AICAR significantly improved autophagy occurrence in BCG-induced macrophages and increased apoptosis while Compound C with siRNA produced opposing effects by attenuating autophagy and apoptosis in BCG-induced macrophages. Thus, the AMPK–mTOR–ULK1 pathway has a dual regulatory role in BCG-induced macrophage autophagy and apoptosis and may have synergistic effects. This study analyzes the mechanism of resistance of host cells to MTB and provides a theoretical basis for new therapeutic strategies and related drug development.

Does Concomitant Use of Methotrexate with JAK Inhibition Confer Benefit for Cardiovascular Outcomes? A Commentary.

This commentary explores the potential cardiovascular (CV) benefits of combining methotrexate (MTX) and Janus kinase inhibitors (JAKis) in the treatment of rheumatoid arthritis (RA). While European guidelines recommend MTX as first-line treatment, concerns about the CV risks associated with JAKis have emerged. This article reviews the existing literature to assess the role of concomitant MTX in reducing CV risk when used with JAKis. Clinical trials confirm the efficacy of JAKis in combination with MTX in terms of treatment outcomes in RA. However, the number of major adverse cardiovascular events (MACEs) reported is too low to draw conclusions on adverse CV outcomes. Indirect evidence does, however, suggest potential protective effects of MTX on CV outcomes, as several mechanisms may contribute to MTX's cardioprotective effects, including reduced inflammation, adenosine monophosphate-activated protein kinase (AMPK) activation, increased cholesterol efflux, and adenosine accumulation. These mechanisms and the available data may support the case for CV benefits of concomitant MTX when JAKis are used in the treatment of patients with RA, although further research is needed. In particular, the lipid paradox associated with RA highlights the complex relationship between RA treatments (MTX, JAKis, tumor necrosis factor (TNF) inhibitors, and interleukin (IL)-6 receptor inhibitors), inflammation, different lipid profiles, and CV risk. In the absence of contraindications and when MTX is tolerated, this commentary suggests the concomitant use of MTX and JAKis as a preferred option for optimizing CV protection in patients with RA.

Unveiling the impacts of metformin on hepatocellular carcinoma: A bioinformatic exploration in cell lines.

The most common type of liver cancer is hepatocellular carcinoma (HCC), accounting for 75-85% of cases. Despite its associated side effects, sorafenib remains the standard treatment for HCC. Given the critical need to improve therapeutic efficacy while minimizing adverse effects, alternative drugs must be thoroughly investigated. Numerous studies indicate that combining sorafenib with metformin results in a more favorable treatment profile. The aim of this study was to employ bioinformatics methodologies to elucidate the molecular pathways and genetic underpinnings of metformin's efficacy in HCC treatment. Genes associated with metformin and its action against HCC (Huh-7 and HepG2 cells) were acquired from the NCBI-GEO data collection by utilizing pre-determined keywords. Subsequently, pathways implicated in metformin-mediated HCC treatment were analyzed through the Kyoto Encyclopedia of Genes and Genomes (KEGG). Our analysis revealed the involvement of multiple pathways, with metabolic pathways implicated in 80% of the total cases. Neurodegenerative pathways were involved in only around 60% of the total cases. These findings align with the multifaceted mechanisms of metformin's action, encompassing adenosine monophosphate-activated protein kinase activation, apoptosis induction, insulin regulation, anti-inflammatory responses, and modulation of cell proliferation. This comprehensive investigation sheds light on the intricate molecular landscape underpinning metformin's therapeutic efficacy in HCC, thereby informing potential avenues for optimizing treatment strategies.

Lung-Targeting Perylenediimide Nanocomposites for Efficient Therapy of Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis, an idiopathic interstitial lung disease with high mortality, remains challenging to treat due to the lack of clinically approved lung-targeting drugs. Herein, we present PDIC-DPC, a perylenediimide derivative that exhibits superior lung-selective enrichment. PDIC-DPC forms nanocomposites with plasma proteins, including fibrinogen beta chain and vitronectin, which bind to pulmonary endothelial receptors for lung-specific accumulation. Moreover, PDIC-DPC significantly suppresses transforming growth factor beta1 and activates adenosine monophosphate-activated protein kinase. As a result, compared to existing therapeutic drugs, PDIC-DPC achieves superior therapeutic outcomes, evidenced by the lowest Ashcroft score, significantly improved pulmonary function, and an extended survival rate in a bleomycin-induced pulmonary fibrosis model. This study elucidates the lung-selective enrichment of assembled prodrug from biological perspectives and affords a platform enabling therapeutic efficiency on idiopathic pulmonary fibrosis.