Loss of AMPK potentiates inflammation by activating the inflammasome after traumatic brain injury in mice.

Traumatic brain injury (TBI) is a significant public health concern characterized by a complex cascade of cellular events. TBI induces adenosine monophosphate-activated protein kinase (AMPK) dysfunction impairs energy balance activates inflammatory cytokines and leads to neuronal damage. AMPK is a key regulator of cellular energy homeostasis during inflammatory responses. Recent research has revealed its key role in modulating the inflammatory process in TBI. Following TBI the activation of AMPK can influence various important pathways and mechanisms including metabolic pathways and inflammatory signaling. Our study investigated the effects of post-TBI loss of AMPK function on functional outcomes inflammasome activation, and inflammatory cytokine production. Male C57BL/6 adult wild-type (WT) and AMPK knockout (AMPK-KO) mice were subjected to a controlled cortical impact (CCI) model of TBI or sham surgery. The mice were tested for behavioral impairment at 24 h post-TBI thereafter, mice were anesthetized, and their brains were quickly removed for histological and biochemical evaluation. In vitro we investigated inflammasome activation in mixed glial cells stimulated with lipopolysaccharides+ Interferon-gamma (LI) (0.1 µg/20 ng/ml LPS/IFNg) for 6 h to induce an inflammatory response. Estimating the nucleotide-binding domain, leucine-rich-containing family pyrin domain containing western blotting ELISA and qRT-PCR performed 3 (NLRP3) inflammasome activation and cytokine production. Our findings suggest that TBI leads to reduced AMPK phosphorylation in WT mice and that the loss of AMPK correlates with worsened behavioral deficits at 24 h post-TBI in AMPK-KO mice as compared to WT mice. Moreover compared with the WT mice AMPK-KO mice exhibit exacerbated NLRP3 inflammasome activation and increased expression of proinflammatory mediators such as IL-1b IL-6 TNF-a iNOS and Cox 2. These results align with the in vitro studies using brain glial cells under inflammatory conditions, demonstrating greater activation of inflammasome components in AMPK-KO mice than in WT mice. Our results highlighted the critical role of AMPK in TBI outcomes. We found that the absence of AMPK worsens behavioral deficits and heightens inflammasome-mediated inflammation thereby exacerbating brain injury after TBI. Restoring AMPK activity after TBI could be a promising therapeutic approach for alleviating TBI-related damage.

LKB1 biology: assessing the therapeutic relevancy of LKB1 inhibitors.

Liver Kinase B1 (LKB1), encoded by Serine-Threonine Kinase 11 (STK11), is a master kinase that regulates cell migration, polarity, proliferation, and metabolism through downstream adenosine monophosphate-activated protein kinase (AMPK) and AMPK-related kinase signalling. Since genetic screens identified STK11 mutations in Peutz-Jeghers Syndrome, STK11 mutants have been implicated in tumourigenesis labelling it as a tumour suppressor. In support of this, several compounds reduce tumour burden through upregulating LKB1 signalling, and LKB1-AMPK agonists are cytotoxic to tumour cells. However, in certain contexts, its role in cancer is paradoxical as LKB1 promotes tumour cell survival by mediating resistance against metabolic and oxidative stressors. LKB1 deficiency has also enhanced the selectivity and cytotoxicity of several cancer therapies. Taken together, there is a need to develop LKB1-specific pharmacological compounds, but prior to developing LKB1 inhibitors, further work is needed to understand LKB1 activity and regulation. However, investigating LKB1 activity is strenuous as cell/tissue type, mutations to the LKB1 signalling pathway, STE-20-related kinase adaptor protein (STRAD) binding, Mouse protein 25-STRAD binding, splicing variants, nucleocytoplasmic shuttling, post-translational modifications, and kinase conformation impact the functional status of LKB1. For these reasons, guidelines to standardize experimental strategies to study LKB1 activity, associate proteins, spliced isoforms, post-translational modifications, and regulation are of upmost importance to the development of LKB1-specific therapies. Therefore, to assess the therapeutic relevancy of LKB1 inhibitors, this review summarizes the importance of LKB1 in cell physiology, highlights contributors to LKB1 activation, and outlines the benefits and risks associated with targeting LKB1.

Fusobacterium nucleatum-induced imbalance in microbiome-derived butyric acid levels promotes the occurrence and development of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) ranks among the most prevalent malignant tumors globally. Recent reports suggest that Fusobacterium nucleatum (F. nucleatum) contributes to the initiation, progression, and prognosis of CRC. Butyrate, a short-chain fatty acid derived from the bacterial fermentation of soluble dietary fiber, is known to inhibit various cancers. This study is designed to explore whether F. nucleatum influences the onset and progression of CRC by impacting the intestinal metabolite butyric acid. AIM: To investigate the mechanism by which F. nucleatum affects CRC occurrence and development. METHODS: Alterations in the gut microbiota of BALB/c mice were observed following the oral administration of F. nucleatum. Additionally, DLD-1 and HCT116 cell lines were exposed to sodium butyrate (NaB) and F. nucleatum in vitro to examine the effects on proliferative proteins and mitochondrial function. RESULTS: Our research indicates that the prevalence of F. nucleatum in fecal samples from CRC patients is significantly greater than in healthy counterparts, while the prevalence of butyrate-producing bacteria is notably lower. In mice colonized with F. nucleatum, the population of butyrate-producing bacteria decreased, resulting in altered levels of butyric acid, a key intestinal metabolite of butyrate. Exposure to NaB can impair mitochondrial morphology and diminish mitochondrial membrane potential in DLD-1 and HCT116 CRC cells. Consequently, this leads to modulated production of adenosine triphosphate and reactive oxygen species, thereby inhibiting cancer cell proliferation. Additionally, NaB triggers the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, blocks the cell cycle in HCT116 and DLD-1 cells, and curtails the proliferation of CRC cells. The combined presence of F. nucleatum and NaB attenuated the effects of the latter. By employing small interfering RNA to suppress AMPK, it was demonstrated that AMPK is essential for NaB's inhibition of CRC cell proliferation. CONCLUSION: F. nucleatum can promote cancer progression through its inhibitory effect on butyric acid, via the AMPK signaling pathway.

Mitochondria-derived peptide is an effective target for treating streptozotocin induced painful diabetic neuropathy through induction of activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator 1alpha -mediated mitochondrial biogenesis.

Painful Diabetic Neuropathy (PDN) is a common diabetes complication that frequently causes severe hyperalgesia and allodynia and presents treatment challenges. Mitochondrial-derived peptide (MOTS-c), a novel mitochondrial-derived peptide, has been shown to regulate glucose metabolism, insulin sensitivity, and inflammatory responses. This study aimed to evaluate the effects of MOTS-c in streptozocin (STZ)-induced PDN model and investigate the putative underlying mechanisms. We found that endogenous MOTS-c levels in plasma and spinal dorsal horn were significantly lower in STZ-treated mice than in control animals. Accordingly, MOTS-c treatment significantly improves STZ-induced weight loss, elevation of blood glucose, mechanical allodynia, and thermal hyperalgesia; however, these effects were blocked by dorsomorphin, an adenosine monophosphate-activated protein kinase (AMPK) inhibitor. In addition, MOTS-c treatment significantly enhanced AMPKα1/2 phosphorylation and PGC-1α expression in the lumbar spinal cord of PDN mice. Mechanistic studies indicated that MOTS-c significantly restored mitochondrial biogenesis, inhibited microglia activation, and decreased the production of pro-inflammatory factors, which contributed to the alleviation of pain. Moreover, MOTS-c decreased STZ-induced pain hypersensitivity in PDN mice by activating AMPK/PGC-1α signaling pathway. This provides the pharmacological and biological evidence for developing mitochondrial peptide-based therapeutic agents for PDN.

Intermittent fasting along with hydroalcoholic extract of Centella-asiatica ameliorates sub-acute hypoxia-induced ischemic stroke in adult zebrafish.

Reduced blood flow (hypoxia) to the brain is thought to be the main cause of strokes because it deprives the brain of oxygen and nutrients. An increasing amount of evidence indicates that the Centella-Asiatica (HA-CA) hydroalcoholic extract has a variety of pharmacological benefits, such as antioxidant activity, neuroprotection, anti-inflammatory qualities, and angiogenesis promotion. Intermittent fasting (IF) has neurological benefits such as anti-inflammatory properties, neuroprotective effects, and the ability to enhance neuroplasticity. The current study evaluates the combined effect of IF (for 1, 6, and 12 days) along with HA-CA (daily up to 12 days) in adult zebrafish subjected to hypoxia every 5 min for 12 days followed by behavioral (novel tank and open-field tank test), biochemical (SOD, GSH-Px, and LPO), inflammatory (IL-10, IL-1ß, and TNF-α), mitochondrial enzyme activities (Complex-I, II, and IV), signaling molecules (AMPK, MAPK, GSK-3ß, Nrf2), and imaging/staining (H&E, TTC, and TEM) analysis. Results show that sub-acute hypoxia promotes the behavioral alterations, and production of radical species and alters the oxidative stress status in brain tissues of zebrafish, along with mitochondrial dysfunction, neuroinflammation, and alteration of signaling molecules. Nevertheless, HA-CA along with IF significantly ameliorates these defects in adult zebrafish as compared to their effects alone. Further, imaging analysis significantly provided evidence of infarct damage along with neuronal and mitochondrial damage which was significantly ameliorated by IF and HA-CA. The use of IF and HA-CA has been proven to enhance the physiological effects of hypoxia in all dimensions.

Beneficial Effects of Fibroblast Growth Factor-1 on Retinal Pigment Epithelial Cells Exposed to High Glucose-Induced Damage: Alleviation of Oxidative Stress, Endoplasmic Reticulum Stress, and Enhancement of Autophagy.

Diabetic retinopathy (DR) severely affects vision in individuals with diabetes. High glucose (HG) induces oxidative stress in retinal cells, a key contributor to DR development. Previous studies suggest that fibroblast growth factor-1 (FGF-1) can mitigate hyperglycemia and protect tissues from HG-induced damage. However, the specific effects and mechanisms of FGF-1 on DR remain unclear. In our study, FGF-1-pretreated adult retinal pigment epithelial (ARPE)-19 cells were employed to investigate. Results indicate that FGF-1 significantly attenuated HG-induced oxidative stress, including reactive oxygen species, DNA damage, protein carbonyl content, and lipid peroxidation. FGF-1 also modulated the expression of oxidative and antioxidative enzymes. Mechanistic investigations showed that HG induced high endoplasmic reticulum (ER) stress and upregulated specific proteins associated with apoptosis. FGF-1 effectively alleviated ER stress, reduced apoptosis, and restored autophagy through the adenosine monophosphate-activated protein kinase/mammalian target of the rapamycin signaling pathway. We observed that the changes induced by HG were dose-dependently reversed by FGF-1. Higher concentrations of FGF-1 (5 and 10 ng/mL) exhibited increased effectiveness in mitigating HG-induced damage, reaching statistical significance (p < 0.05). In conclusion, our study underscores the promising potential of FGF-1 as a safeguard against DR. FGF-1 emerges as a formidable intervention, attenuating oxidative stress, ER stress, and apoptosis, while concurrently promoting autophagy. This multifaceted impact positions FGF-1 as a compelling candidate for alleviating retinal cell damage in the complex pathogenesis of DR.

The potential of herbal drugs to treat heart failure: The roles of Sirt1/AMPK.

Heart failure (HF) is a highly morbid syndrome that seriously affects the physical and mental health of patients and generates an enormous socio-economic burden. In addition to cardiac myocyte oxidative stress and apoptosis, which are considered mechanisms for the development of HF, alterations in cardiac energy metabolism and pathological autophagy also contribute to cardiac abnormalities and ultimately HF. Silent information regulator 1 (Sirt1) and adenosine monophosphate-activated protein kinase (AMPK) are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases and phosphorylated kinases, respectively. They play similar roles in regulating some pathological processes of the heart through regulating targets such as peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), protein 38 mitogen-activated protein kinase (p38 MAPK), peroxisome proliferator-activated receptors (PPARs), and mammalian target of rapamycin (mTOR). We summarized the synergistic effects of Sirt1 and AMPK in the heart, and listed the traditional Chinese medicine (TCM) that exhibit cardioprotective properties by modulating the Sirt1/AMPK pathway, to provide a basis for the development of Sirt1/AMPK activators or inhibitors for the treatment of HF and other cardiovascular diseases (CVDs).

Targeted metabolomics reveals the aberrant energy status in diabetic peripheral neuropathy and the neuroprotective mechanism of traditional Chinese medicine JinMaiTong.

Diabetic peripheral neuropathy (DPN) is a common and devastating complication of diabetes, for which effective therapies are currently lacking. Disturbed energy status plays a crucial role in DPN pathogenesis. However, the integrated profile of energy metabolism, especially the central carbohydrate metabolism, remains unclear in DPN. Here, we developed a metabolomics approach by targeting 56 metabolites using high-performance ion chromatography-tandem mass spectrometry (HPIC-MS/MS) to illustrate the integrative characteristics of central carbohydrate metabolism in patients with DPN and streptozotocin-induced DPN rats. Furthermore, JinMaiTong (JMT), a traditional Chinese medicine (TCM) formula, was found to be effective for DPN, improving the peripheral neurological function and alleviating the neuropathology of DPN rats even after demyelination and axonal degeneration. JMT ameliorated DPN by regulating the aberrant energy balance and mitochondrial functions, including excessive glycolysis restoration, tricarboxylic acid cycle improvement, and increased adenosine triphosphate (ATP) generation. Bioenergetic profile was aberrant in cultured rat Schwann cells under high-glucose conditions, which was remarkably corrected by JMT treatment. In-vivo and in-vitro studies revealed that these effects of JMT were mainly attributed to the activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and downstream peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Our results expand the therapeutic framework for DPN and suggest the integrative modulation of energy metabolism using TCMs, such as JMT, as an effective strategy for its treatment.

Inspiring Tactics with the Improvement of Mitophagy and Redox Balance for the Development of Innovative Treatment against Polycystic Kidney Disease.

Polycystic kidney disease (PKD) is the most common genetic form of chronic kidney disease (CKD), and it involves the development of multiple kidney cysts. Not enough medical breakthroughs have been made against PKD, a condition which features regional hypoxia and activation of the hypoxia-inducible factor (HIF) pathway. The following pathology of CKD can severely instigate kidney damage and/or renal failure. Significant evidence verifies an imperative role for mitophagy in normal kidney physiology and the pathology of CKD and/or PKD. Mitophagy serves as important component of mitochondrial quality control by removing impaired/dysfunctional mitochondria from the cell to warrant redox homeostasis and sustain cell viability. Interestingly, treatment with the peroxisome proliferator-activated receptor-α (PPAR-α) agonist could reduce the pathology of PDK and might improve the renal function of the disease via the modulation of mitophagy, as well as the condition of gut microbiome. Suitable modulation of mitophagy might be a favorable tactic for the prevention and/or treatment of kidney diseases such as PKD and CKD.

Hyperglycemia exacerbates cerebral ischemia/reperfusion injury by up-regulating autophagy through p53-Sesn2-AMPK pathway.

Hyperglycemia exacerbates ischemic brain injury by up-regulating autophagy. However, the underlying mechanisms are unknown. This study aims to determine whether hyperglycemia activates autophagy through the p53-Sesn2-AMPK signaling pathway. Rats were subjected to 30-min middle cerebral artery occlusion (MCAO) with reperfusion for 1- and 3-day under normo- and hyperglycemic conditions; and HT22 cells were exposed to oxygen deprivation (OG) or oxygen-glucose deprivation and re-oxygenation (OGD/R) with high glucose. Autophagy inhibitors, 3-MA and ARI, were used both in vivo and in vitro. The results showed that, compared with the normoglycemia group (NG), hyperglycemia (HG) increased infarct volume and apoptosis in penumbra area, worsened neurological deficit, and augmented autophagy. after MCAO followed by 1-day reperfusion. Further, HG promoted the conversion of LC-3I to LC-3II, decreased p62, increased protein levels of aldose reductase, p53, P-p53ser15, Sesn2, AMPK and numbers of autophagosomes and autolysosomes, detected by transmission electron microscopy and mRFP-GFP-LC3 molecular probe, in the cerebral cortex after ischemia and reperfusion injury in animals or in cultured HT22 cells exposed to hypoxia with high glucose content. Finally, experiments with autophagy inhibitors 3-MA and aldose reductase inhibitor (ARI) revealed that while both inhibitors reduced the number of TUNEL positive neurons and reversed the effects of hyperglycemic ischemia on LC3 and p62, only ARI decreased the levels of p53, P-p53ser15. These results suggested that hyperglycemia might induce excessive autophagy to aggravate the brain injury resulted from I/R and that hyperglycemia might activate the p53-Sesn2-AMPK signaling pathway, in addition to the classical PI3K/AKT/mTOR autophagy pathway.

Viability Profiles of Normal and Cancer Bladder Cells With Metformin, Nitrate and Adenosine Monophosphate-Activated Protein Kinase Inhibitor.

Background: There is no literature report on how metformin and adenosine monophosphate-activated protein kinase (AMPK) inhibitor affect normal and cancer bladder cells under the presence of nitrate. Methods: Various treatment concentrations and methods were used to study the effects of nitrate, metformin, and/or AMPK inhibitor on normal and/or cancer bladder cells. Normal bladder cells were exposed to nitrate or metformin alone or in combination. The effects of AMPK on normal bladder cells were investigated with nitrate and metformin pretreatment. The effects of varying metformin concentrations on cancer bladder cells were examined as well. Results: Metformin has produced almost no changes in cell viability of normal cells with various concentrations. Addition of both nitrate and metformin at the same time resulted in less than 17% cell viability as compared to the controlled values; however, this value is about 10% better than nitrate alone for 24 h and approximate 27% better for 48 h. Pre-treatment of normal cells with AMPK inhibitor for 6 h prior to addition of metformin and nitrate reduced the cell viability greatly. The treatment of cancer bladder cells with metformin indicated an inverse relationship between metformin concentration and cancer bladder cell viability. Conclusion: Metformin assisted normal bladder cells in surviving in the presence of nitrate, but its total survival was greatly reduced by AMPK inhibitors. Metformin inhibited the growth of bladder cancer cells.

New Function Annotation of PROSER2 in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis due to the absence of diagnostic markers and molecular targets. Here, we took an unconventional approach to identify new molecular targets for pancreatic cancer. We chose uncharacterized protein evidence level 1 without function annotation from extensive proteomic research on pancreatic cancer and focused on proline and serine-rich 2 (PROSER2), which ranked high in the cell membrane and cytoplasm. In our study using cell lines and patient-derived orthotopic xenograft cells, PROSER2 exhibited a higher expression in cells derived from primary tumors than in those from metastatic tissues. PROSER2 was localized in the cell membrane and cytosol by immunocytochemistry. PROSER2 overexpression significantly reduced the metastatic ability of cancer cells, whereas its suppression had the opposite effect. Proteomic analysis revealed that PROSER2 interacts with STK25 and PDCD10, and their binding was confirmed by immunoprecipitation and immunocytochemistry. STK25 knockdown enhanced metastasis by decreasing p-AMPK levels, whereas PROSER2-overexpressing cells increased the level of p-AMPK, indicating that PROSER2 suppresses invasion via the AMPK pathway by interacting with STK25. This is the first demonstration of the novel role of PROSER2 in antagonizing tumor progression via the STK25-AMPK pathway in PDAC. LC-MS/MS data are available at MassIVE (MSV000092953) and ProteomeXchange (PXD045646).

Impact of metformin on hypothalamic-pituitary-thyroid axis activity in women with autoimmune and non-autoimmune subclinical hypothyroidism: a pilot study.

BACKGROUND: Metformin reduces plasma TSH levels if these levels are elevated. No study has investigated whether the hormonal effects of metformin are impacted by thyroid autoimmunity. The current study aimed to compare the effect of metformin on hypothalamic-pituitary-thyroid axis activity between subjects with mild hypothyroidism of different origins. METHODS: The study population consisted of two groups of women with prediabetes and mildly elevated TSH levels, matched by age, insulin sensitivity, TSH, and thyroid hormone levels. Group A included 26 women with autoimmune thyroiditis, while group B enrolled 26 individuals with hypothyroidism of non-autoimmune origin. Both groups were treated with metformin (2.55-3 g daily). Circulating levels of TSH, total and free thyroid hormones, glucose, insulin, prolactin, high-sensitivity C-reactive protein (hsCRP) and 25-hydroxyvitamin D, concentrations of thyroid antibodies, and structure parameters of thyroid homeostasis were assessed at baseline and 6 months later. RESULTS: All patients completed the study. At baseline, both groups differed in concentrations of thyroid peroxidase antibodies, thyroglobulin antibodies, hsCRP, and 25-hydroxyvitamin D. The drug reduced TSH and Jostel's index, with no difference between the study groups. The improvement in insulin sensitivity, observed in both groups, was more pronounced in group B than in group A. In women with autoimmune hypothyroidism, the drug increased SPINA-GT and decreased hsCRP levels. The remaining markers did not change throughout the study. CONCLUSIONS: The obtained results suggest that, despite differences in thyroid output, the impact of metformin on TSH levels is similar in hypothyroid women with and without thyroid autoimmunity.

Overexpression of salusin­ß downregulates adipoR1 expression to prevent fatty acid oxidation in HepG2 cells.

Salusin­ß and adiponectin receptor 1 (adipoR1) serve important roles in the development of certain cardiovascular diseases and lipid metabolism. However, to the best of our knowledge, the relationship between salusin­ß and adipoR1, and their underlying mechanisms of action, currently remain unclear. In the present study, lentiviral vectors designed to overexpress salusin­ß or knock down salusin­ß expression were used in 293T and HepG2 cells. Semi­quantitative PCR was performed to investigate the relationship between salusin­ß and adipoR1 mRNA expression in 293T cells. Western blotting was used to assess the protein expression levels of adipoR1, adenosine monophosphate­activated protein kinase (AMPK), acetyl­CoA carboxylase (ACC) and carnitine palmitoyl transferase 1A (CPT­1A) in transfected HepG2 cells. Simultaneously, HepG2 cells were treated with an adipoR1 inhibitor (thapsigargin) or agonist (AdipoRon) and the resultant changes in the expression levels of the aforementioned proteins were observed. Oil Red O staining and measurements of cellular triglyceride levels were performed to assess the extent of lipid accumulation in HepG2 cells. The results demonstrated that salusin­ß overexpression downregulated adipoR1 expression and inhibited the phosphorylation of AMPK and ACC, which led to decreased CPT­1A protein expression. By contrast, salusin­ß knockdown increased adipoR1 expression and promoted the phosphorylation of AMPK and ACC, which conversely enhanced CPT­1A protein expression. Treatment with adipoR1 agonist, AdipoRon, reversed the effects of salusin­ß overexpression. In addition, salusin­ß overexpression enhanced intracellular lipid accumulation in HepG2 cells induced by free fatty acid treatment. These findings highlighted the potential regulatory role of salusin­ß in adipoR1­mediated signaling pathways. To conclude, the present study provided insights into the regulation of fatty acid metabolism by the liver. In particular, salusin­ß may serve as a potential target for the therapeutic intervention of metabolic disorders of lipids.

Research Progress on Active Ingredients of Chinese Medicine Based on AMPK Signaling Pathway to Improve Insulin Resistance in T2DM / 中国实验方剂学杂志

Insulin resistance （IR） is an important pathological and physiological mechanism of type 2 diabetes （T2DM）， and the treatment of IR has become the key to the prevention and treatment of T2DM. IR is a state of insensitivity or reduced sensitivity of insulin-stimulated tissue cells to glucose， resulting in cells that are unable to efficiently take up glucose in the bloodstream and thus causing hyperglycemia. Adenosine monophosphate-activated protein kinase （AMPK） is an energy-sensing enzyme that can regulate multiple metabolic pathways and maintain the stability of adenosine triphosphate （ATP） in the cell. In recent years， traditional Chinese medicine （TCM） has played an increasingly important role in the prevention and treatment of T2DM. The research on exploring the AMPK signaling pathway of TCM intervention in the progress of T2DM has gradually increased. Many pharmacological studies have shown that TCM has advantages such as safety and high efficiency in the prevention and treatment of T2DM. AMPK signaling pathway is one of the key pathways for the active ingredients of TCM and TCM extracts to improve IR. Active ingredients such as phenols， flavonoids， polysaccharides， alkaloids， and saponins， as well as other herbal extracts can improve IR by activating the AMPK signaling pathway cascade response， thereby improving IR by regulating glucolipid metabolism， inhibiting inflammatory response， anti-oxidative stress and maintaining mitochondrial homeostasis. Based on this， this paper reviews the pharmacological and experimental research results of TCM intervening the AMPK signaling pathway to improve IR in recent years， expecting to provide reference for further research， development and application of TCM in intervening IR and treating T2DM.

Protective Mechanism of Paeoniflorin on Mice with Ulcerative Colitis Based on AMPK/mTOR Autophagy Pathway / 中国实验方剂学杂志

ObjectiveTo explore the protective mechanism of paeoniflorin on mice with ulcerative colitis （UC） through the adenosine monophosphate-activated protein kinase （AMPK）/mammalian target of rapamycin （mTOR） autophagy pathway. MethodUC mouse model was established by allowing mice freely drink 4% DSS， and 56 BALB/c male mice were randomly divided into model group， AMPK inhibitor group （20 mg·kg-1）， paeoniflorin （50 mg·kg-1） + inhibitor （20 mg·kg-1） group， and high dose （50 mg·kg-1）， medium dose （25 mg·kg-1）， and low dose （12.5 mg·kg-1） paeoniflorin groups. After seven days of drug intervention， the protective effect of paeoniflorin on mice with UC was determined by comparing the body weight， disease activity index （DAI） changes， and Hematoxylin-eosin （HE） staining results. Enzyme linked immunosorbent assay （ELISA） was used to detect the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in the serum of mice in each group， and immunofluorescence was utilized to detect microtubule-associated protein 1 light chain 3 （LC3） content in the colon， AMPK， mTOR proteins， and their phosphorylated proteins including p-AMPK and p-mTOR in the colon tissue were detected by Western blot， and the mRNA expression levels of AMPK， mTOR， Beclin1， LC3， and p62 were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the blank group， the model group showed a decrease in body mass， an increase in DAI score， and severe pathological damage to the colon. The levels of inflammatory factors including TNF-α and IL-6 increased in serum （P<0.01）， while the protein levels of LC3 and p-AMPK/AMPK were down-regulated in colon tissue， and those of p-mTOR/mTOR were up-regulated （P<0.01）. The mRNA expression levels of AMPK and LC3 were down-regulated， while the mRNA expression levels of mTOR and p62 were up-regulated （P<0.01）. Compared with the model group and the paeoniflorin + inhibitor group， the mice treated with paeoniflorin showed an increase in body mass， a decrease in DAI score， a reduction in pathological damage to colon tissue， and a reduction in the levels of inflammatory factors of TNF-α and IL-6 in serum （P<0.05）. The protein levels of LC3 and p-AMPK/AMPK in colon tissue were up-regulated， while the protein levels of p-mTOR/mTOR were down-regulated （P<0.01）. The mRNA expression levels of AMPK， Beclin1， and LC3 were up-regulated， while the mRNA expression of mTOR and p62 were down-regulated （P<0.01）. The colon tissue of the inhibitor group was severely damaged， and the trend of various indicators was completely opposite to that of the high dose paeoniflorin group. ConclusionPaeoniflorin can enhance autophagy and reduce inflammatory damage in mice with UC by activating the AMPK/mTOR signaling pathway and thus play a protective role.

Danggui Shaoyaosan Regulates Autophagy via AMPK/mTOR/ULK1 Signaling Pathway in Rat Model of Metabolism-associated Fatty Liver Disease / 中国实验方剂学杂志

ObjectiveTo investigate the regulatory effect of Danggui Shaoyaosan on adenosine monophosphate-activated protein kinase （AMPK）/mammalian target of rapamycin （mTOR）/Unc-51-like kinase-1 （ULK1） signaling pathway in the rat model of metabolism-associated fatty liver disease （MAFLD）. MethodSixty SD rats were randomized into control， model， western medicine （polyene phosphatidylcholine capsules，0.144 g·kg-1）， and low-， medium-， and high-dose （2.44， 4.88， 9.76 g·kg-1， respectively） Danggui Shaoyaosan groups. After being fed with a high-fat diet for 8 weeks， the rats in each group were administrated with corresponding drugs for 4 weeks. At the end of drug treatment， serum and liver tissue were collected for subsequent determination of related indicators. ResultCompared with the control group， the model group showed increased contents of total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C） and activities of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） in the serum， increased contents of TC， TG， and free fatty acids （FFAs） in the liver （P<0.01）， and decreased content of high-density lipoprotein cholesterol （HDL-C） in the serum （P<0.01）. Furthermore， the model group showed down-regulated protein levels of p-AMPK， microtubule-associated protein 1 light chain 3B （LC3B） Ⅱ， Beclin1， and ULK1 （P<0.01） and up-regulated protein levels of p-mTOR and ubiquitin-binding protein p62 in the liver （P<0.01）. The hepatic steatosis was obvious and the NAFLD activity score （NAS） and oil red O staining area increased in the model group， （P<0.05， P<0.01）. Compared with the model group， Danggui Shaoyaosan reduced the contents of TC and TG and the activities of ALT and AST in the serum， lowered the levels of TC， TG， and FFA in the liver， down-regulated the protein levels of p-mTOR and p62 （P<0.01）， elevated the serum HDL-C level， and up-regulated the protein levels of p-AMPK， LCBⅡ， Beclin1， and ULK1 in the liver （P<0.05， P<0.01）. Moreover， it alleviated hepatic steatosis and decreased the NAS and oil red O staining area （P<0.05， P<0.01）. ConclusionDanggui Shaoyaosan has therapeutic effect on MAFLD rats by regulating AMPK/mTOR/ULK1 signaling pathway to enhance autophagy.

Metformin Prevents Cocaine Sensitization: Involvement of Adenosine Monophosphate-Activated Protein Kinase Trafficking between Subcellular Compartments in the Corticostriatal Reward Circuit.

Repeated cocaine exposure produces an enhanced locomotor response (sensitization) paralleled by biological adaptations in the brain. Previous studies demonstrated region-specific responsivity of adenosine monophosphate-activated protein kinase (AMPK) to repeated cocaine exposure. AMPK maintains cellular energy homeostasis at the organismal and cellular levels. Here, our objective was to quantify changes in phosphorylated (active) and total AMPK in the cytosol and synaptosome of the medial prefrontal cortex, nucleus accumbens, and dorsal striatum following acute or sensitizing cocaine injections. Brain region and cellular compartment selective changes in AMPK and pAMPK were found with some differences associated with acute withdrawal versus ongoing cocaine treatment. Our additional goal was to determine the behavioral and molecular effects of pretreatment with the indirect AMPK activator metformin. Metformin potentiated the locomotor activating effects of acute cocaine but blocked the development of sensitization. Sex differences largely obscured any protein-level treatment group effects, although pAMPK in the NAc shell cytosol was surprisingly reduced by metformin in rats receiving repeated cocaine. The rationale for these studies was to inform our understanding of AMPK activation dynamics in subcellular compartments and provide additional support for repurposing metformin for treating cocaine use disorder.

Metformin effects on cardiac parameters in non-diabetic Iraqi patients with heart failure and mid-range ejection fraction - a comparative two-arm parallel clinical study.

Heart failure (HF) remains a difficult challenge to the healthcare system, necessitating promoting interventions and multidrug management. Metformin, typically used to manage diabetes, has emerged as a promising intervention in the treatment of HF. This study aimed to assess the effect of adding metformin to the standard treatment of HF on cardiac parameters. This clinical study comprised 60 newly diagnosed HF patients randomly assigned to two groups: Group C received standard HF treatment, while Group M received standard HF treatment in addition to daily metformin (500 mg). After 3 months of treatment, group M showed a significantly higher ejection fraction (EF) compared to Group C (6.1% and 3.2%, respectively; p-value=0.023) and a reduction in the left ventricular end-diastolic pressure (LVEDD) (0.28, and 0.21 mm respectively; p-value=0.029). No significant differences were observed in the interventricular septal thickness (IVST) or left ventricular end-systolic pressure (LVESD). For cardiac markers, N-Terminal pro-BNP (NT-proBNP) showed the highest reduction in Group M compared to Group C (719.9 pg/ml and 271.9 pg/ml respectively; p-value=0.009). No significant changes were reported for soluble ST2. Metformin demonstrated cardiac protective effects by increasing EF and reducing NT-proBNP. Given its affordability and accessibility, metformin offers a valuable addition to the current HF treatment options. This positive effect may be attributed to mechanisms that enhance the impact of conventional HF treatments or vice versa.

Extracellular Superoxide Dismutase Attenuates Hepatic Oxidative Stress in Nonalcoholic Fatty Liver Disease through the Adenosine Monophosphate-Activated Protein Kinase Activation.

Oxidative stress is key in type 2 diabetes-associated nonalcoholic fatty liver disease (NAFLD). We explored whether extracellular superoxide dismutase (EC-SOD) activates adenosine monophosphate-activated protein kinase (AMPK) to enhance antioxidant synthesis and lipid metabolism in NAFLD. Human recombinant EC-SOD (hEC-SOD) was administered to 8-week-old male C57BLKS/J db/db mice through intraperitoneal injection once a week for 8 weeks. Target molecules involved in oxidative stress and lipid metabolism were investigated. hEC-SOD improved insulin resistance and systemic and hepatic oxidative stress characterized by increases in urinary 8-hydroxy-deoxyguanosine and 8-isoprostane levels in db/db mice and a decrease in DHE expression in the liver, respectively. Hepatic SOD3 expression in db/db mice was reversed by hEC-SOD, which improved hepatic steatosis, inflammation with M2 polarization, apoptosis, autophagy, fibrosis and lipid metabolism in db/db mice, as reflected by the changes in serum and hepatic markers, monocyte chemoattractant protein-1, tumor necrosis factor-α, TUNEL-positive cells, Bcl-2/BAX ratio, beclin1 and LC3-II/LC3-1. At the molecular level, hEC-SOD increased phosphorylated-AMPK related to CaMKKß, activation of peroxisome proliferative-activated receptor-gamma coactivator (PGC)-1α and dephosphorylation of forkhead box O (FoxO)1 and their subsequent downstream signaling. In HepG2Cs cells using AMPKα1 and AMPKα2 siRNA, hEC-SOD demonstrated a protective effect via the direct activation of both AMPK-PGC-1α and AMPK-FoxO1. EC-SOD might be a potential therapeutic agent for NAFLD through the activation of AMPK-PGC-1α and AMPK-FoxO1 signaling in hepatocytes, which modulates lipid metabolism, leading to anti-inflammatory, antioxidative and antiapoptotic effects and improving autophagy in the liver.