Searching Inhibitors of Adenosine Kinase by Simulation Methods

Searching new inhibitors of adenosine kinase （AK） is still drawing attention of experimental scientists. A better and solid model is here proposed by means of simulation methods from different ways, the direct analysis of receptor itself, the conventional 3D-QSAR methods and the integration of docking method and the conventional QSAR analysis.

Metformin promotes angiogenesis and functional recovery in aged mice after spinal cord injury by adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway

Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of angiogenesis during the regeneration process,we hypothesized that metformin activates the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway in endothelial cells,thereby promoting microvascular regeneration in aged mice after spinal cord injury.In this study,we established young and aged mouse models of contusive spinal cord injury using a modified Allen method.We found that aging hindered the recovery of neurological function and the formation of blood vessels in the spinal cord.Treatment with metformin promoted spinal cord microvascular endothelial cell migration and blood vessel formation in vitro.Furthermore,intraperitoneal injection of metformin in an in vivo model promoted endothelial cell proliferation and increased the density of new blood vessels in the spinal cord,thereby improving neurological function.The role of metformin was reversed by compound C,an adenosine monophosphate-activated protein kinase inhibitor,both in vivo and in vitro,suggesting that the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway likely regulates metformin-mediated angiogenesis after spinal cord injury.These findings suggest that metformin promotes vascular regeneration in the injured spinal cord by activating the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway,thereby improving the neurological function of aged mice after spinal cord injury.

Adenosine monophosphate-activated protein kinase activation enhances embryonic neural stem cell apoptosis in a mouse model of amyotrophic lateral sclerosis

Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible to oxidative injury, resulting in a propensity for neurodegeneration at later stages. In this study, embryonic neural stem cells obtained from human superoxide dis- mutase 1 mutant （SOD1G93A） and wild-type （SOD1wv） mouse models were exposed to H202. We assayed cell viability with mitochondrial succinic dehydrogenase colorimetric reagent, and measured cell apoptosis by flow cytometry. Moreover, we evaluated the expression of the adenos- ine monophosphate-activated protein kinase （AMPK） ct-subunit, paired box 3 （Pax3） protein, and p53 in western blot analyses. Compared with SOD1wr cells, SOD1~93A embryonic neural stem cells were more likely to undergo H202-induced apoptosis. Phosphorylation of AMPKct in SOD1G93A cells was higher than that in SOD1wr cells. Pax3 expression was inversely correlated with the phosphorylation levels of AMPKct. p53 protein levels were also correlated with AMPKct phosphorylation levels. Compound C, an inhibitor of AMPKa, attenuated the effects of H20~. These results suggest that embryonic neural stem cells from SOD1C93A mice are more susceptible to apoptosis in the presence of oxidative stress compared with those from wild-type controls, and the effects are mainly mediated by Pax3 and p53 in the AMPKa pathway.

Electroacupuncture preconditioning attenuates ischemic brain injury by activation of the adenosine monophosphate-activated protein kinase signaling pathway

Electroacupuncture has therapeutic effects on ischemic brain injury, but its mechanism is still poorly understood. In this study, mice were stimulated by electroacupuncture at the Baihui（GV20） acupoint for 30 minutes at 1 m A and 2/15 Hz for 5 consecutive days. A cerebral ischemia model was established by ligating the bilateral common carotid artery for 15 minutes. At 72 hours after injury, neuronal injury in the mouse hippocampus had lessened, and the number of terminal deoxynucleotide transferase-mediated d UTP nick-end labeling-positive cells reduced after electroacupuncture treatment. Moreover, expression of adenosine monophosphate-activated protein kinase α（AMPKα） and phosphorylated AMPKα was up-regulated. Intraperitoneal injection of the AMPK antagonist, compound C, suppressed this phenomenon. Our findings suggest that electroacupuncture preconditioning alleviates ischemic brain injury via AMPK activation.

Suppressing high mobility group box-1 release alleviates morphine tolerance via the adenosine5'-monophosphate-activated protein kinase/heme oxygenase-1 pathway

Opioids,such as morphine,are the most potent drugs used to treat pain.Long-term use results in high tolerance to morphine.High mobility group box-1(HMGB1) has been shown to participate in neuropathic or inflammatory pain,but its role in morphine tolerance is unclear.In this study,we established rat and mouse models of morphine tolerance by intrathecal injection of morphine for 7 consecutive days.We found that morphine induced rat spinal cord neurons to release a large amount of HMGB1.HMGB1 regulated nuclear factor κB p65 phosphorylation and interleukin-1β production by increasing Toll-like receptor 4receptor expression in microglia,thereby inducing morphine tolerance.Glycyrrhizin,an HMGB1 inhibito r,markedly attenuated chronic morphine tole rance in the mouse model.Finally,compound C(adenosine 5’-monophosphate-activated protein kinase inhibitor) and zinc protoporphyrin(heme oxygenase-1 inhibitor)alleviated the morphine-induced release of HMGB1 and reduced nuclear factor κB p65 phosphorylation and interleukin-1β production in a mouse model of morphine tolerance and an SH-SY5Y cell model of morphine tole rance,and alleviated morphine tolerance in the mouse model.These findings suggest that morphine induces HMGB1 release via the adenosine 5’-monophosphate-activated protein kinase/heme oxygenase-1 signaling pathway,and that inhibiting this signaling pathway can effectively reduce morphine tole rance.

AB015.Metabolic stress in glaucoma engages early activation of the energy biosensor adenosine monophosphate-activated protein kinase leading to neuronal dysfunction

Background:Metabolic stress has been proposed to contribute to neuronal damage in glaucoma,but the mechanism driving this response is not understood.The adenosine monophosphate-activated protein kinase(AMPK)is a master regulator of energy homeostasis that becomes active at the onset of energy stress.AMPK is a potent inhibitor of the mammalian target of rapamycin complex 1(mTORC1),which we showed is essential for the maintenance of retinal ganglion cell(RGC)dendrites,synapses,and survival.Here,we tested the hypothesis that AMPK is an early mediator of metabolic stress in glaucoma.Methods:Unilateral elevation of intraocular pressure was induced by injection of magnetic microbeads into the anterior chamber of mice expressing yellow fluorescent protein in RGCs.Inhibition of AMPK was achieved by administration of siRNA or compound C.RGC dendritic trees were 3D-reconstructed and analyzed with Imaris(Bitplane),and survival was assessed by counting Brn3a or RBPMS-labeled soma and axons in the optic nerve.RGC function was examined by quantification of anterograde axonal transport after intraocular administration of cholera toxinβ-subunit.Retinas from glaucoma patients were analyzed for expression of active AMPK.Results:Ocular hypertension triggered rapid upregulation of AMPK activity in RGCs concomitant with loss of mTORC1 function.AMPK inhibition with compound C or siRNA effectively restored mTORC1 activity and promoted an increase in total dendritic length,surface and complexity relative to control retinas.Attenuation of AMPK activity led to robust RGC soma and axon survival.For example,95%of RGCs(2,983±258 RGCs/mm2,mean±S.E.M.)survived with compound C compared to 77%in vehicle-treated eyes(2,430±233 RGCs/mm2)(ANOVA,P<0.001)at three weeks after glaucoma induction(n=8-10/group).Importantly,blockade of AMPK activity effectively restored anterograde axonal transport.Lastly,RGC-specific upregulation of AMPK activity was detected in human glaucomatous retinas relative to age-matched controls(n=10/group).Conclusions:Metabolic stress in glaucoma involves AMPK activation and mTORC1 inhibition promoting early RGC dendritic pathology,dysfunction and neurodegeneration.

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.

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 receptorγcoactivator 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).

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 prolif-eration.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.

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 inflam-mation 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.

Beneficial effects of metformin on primary cardiomyocytes via activation of adenosine monophosphate-activated protein kinase

Background Metformin has become a cornerstone in the treatment of patients with type-2 diabetes. Accumulated evidence suggests that metformin supports direct cardiovascular effects. The present study aimed to investigate if metformin has beneficial effects on primary cardiomyocytes damaged by H2O2, and reveal the potential mechanism of action of metformin. Methods Cardiomyocytes were incubated in the presence of 100μmol/L H2O2 for 12 hours. Cardiomyocytes were pretreated with metformin at different concentrations and time and with aminoimidazole carboxamide ribonucleotide （AICAR） （500μmol/L）, an adenosine monophophate （AMP）-activated protein kinase （AMPK） agonist for 60 minutes before the addition of H2O2. Other cells were preincubated with compound C （an AMPK antagonist, 20μmol/L） for 4 hours. The viability and apoptosis of cells were analyzed. AMPK, endothelial nitric oxide synthase （eNOS）, and transforming growth factor （TGF）-β1 were analyzed using immunblotting. Results Metformin had antagonistic effects on the influences of H2O2 on cell viability and attenuated oxidative stress-induced apoptosis. Metformin also increased phosphorylation of AMPK and eNOS, and reduced the expression of TGF-β1, basic fibroblast growth factor （bFGF）, and tumor necrosis factor （TNF）-α. Conclusions Metformin has beneficial effects on cardiomyocytes, and this effect involves activation of the AMPK-eNOS pathway. Metformin may be potentially beneficial for the treatment of heart disease.

Metformin inhibits nuclear factor-κB activation and inflammatory cytokines expression induced by high glucose via adenosine monophosphate-activated protein kinase activation in rat glomerular mesangial cells in vitro

Background The renoprotective mechanisms of adenosine monophosphate （AMP）-activated protein kinase （AMPK） agonist-metformin have not been stated clearly.We hypothesized that metformin may ameliorate inflammation via AMPK interaction with critical inflammatory cytokines The aim of this study was to observe the effects of metformin on expression of nuclear factor-κB （NF-κB）,monocyte chemoattractant protein-1 （MCP-1）,intercellular adhesion molecule-1 （ICAM-1） and transforming growth factor-beta 1 （TGF-β1） induced by high glucose （HG） in cultured rat glomerular mesangial cells （MCs）.Methods MCs were cultured in the medium with normal concentration glucose （group NG,5.6 mmol/L）,high concentration glucose （group HG,25 mmol/L） and different concentrations of metformin （group M1,M2,M3）.After 48-hour exposure,the supernatants and MCs were collected.The expression of NF-κB,MCP-1,ICAM-1,and TGF-β1 mRNA was analyzed by real time polymerase chain reaction.Westem blotting was used to detect the expression of AMPK,phospho-Thr-172 AMPK （p-AMPK）,NF-κB p65,MCP-1,ICAM-1,and TGF-β1 protein.Results After stimulated by HG,the expression of NF-κB,MCP-1,ICAM-1,TGF-β1 mRNA and protein of MCs in group HG increased significantly compared with group NG （P ＜0.05）.Both genes and protein expression of NF-κB,MCP-1,ICAM-1,TGF-β1 of MCs induced by high glucose were markedly reduced after metformin treatment in a dose-dependent manner （P ＜0.05）.The expression of p-AMPK increased with the rising of metformin concentration,presenting the opposite trend,while the level of total-AMPK protein was unchanged with exposure to HG or metformin.Conlusion Metformin can suppress the expression of NF-κB,MCP-1,ICAM-1 and TGF-β1 of glomerular MCs induced by high glucose via AMPK activation,which may partlv contribute to its reno-protection.

Polyethylene glycol rinse solution:An effective way to prevent ischemia-reperfusion injury

AIM: To test whether a new rinse solution containing polyethylene glycol 35 (PEG-35) could prevent ischemia-reperfusion injury (IRI) in liver grafts.

Dan-gua Fang (丹瓜方) Improves Glycolipid Metabolic Disorders by Promoting Hepatic Adenosine 5'-monophosphate Activated Protein Kinase Expression in Diabetic Goto-kakizaki Rats

Objective：To investigate the effect of Dan-gua Fang（丹瓜方） on adenosine 5’-monophosphate（AMP） activated protein kinase（AMPK） α expression in liver and subsequent improvement of glucose and lipid metabolism.Methods：Forty 13-week-old diabetic Goto-Kakizaki（GK） rats were randomly divided into model,Dan-gua Fang,metformin and simvastatin groups（n=10 for each）,and fed high-fat diet ad libitum.Ten Wistar rats were used as normal group and fed normal diet.After 24 weeks,liver expression of AMPK α mRNA was assessed by real-time PCR.AMPK α and phospho-AMPK α protein expression in liver was evaluated by Western blot.Liver histomorphology was carried out after hematoxylin-eosin staining,and blood glucose（BG）,glycosylated hemoglobin A1c（HbA1c）,food intake and body weight recorded.Results：Similar AMPK α mRNA levels were found in the Dan-gua Fang group and normal group,slightly higher than the values obtained for the remaining groups（P〈0.05）.AMPK α protein expression in the Dan-gua Fang group animals was similar to other diabetic rats,whereas phospho-AMPK α（Thr-172） protein levels were markedly higher than in the metformin group and simvastatin group（P〈0.05）,respectively.However,phosphor-AMPKa/AMPK α ratios were similar in all groups.Dan-gua Fang reduced fasting blood glucose with similar strength to metformin,and was superior in reducing cholesterol,triglycerides,high-density lipoprotein cholesterol as well as improving low-density lipoprotein cholesterol in comparison with simvastatin and metformin.Dan-gua Fang decreases plasma alanine aminotransferase（ALT） significantly.Conclusion：Dan-gua Fang,while treating phlegm-stasis,could decrease BG and lipid in type 2 diabetic GK rats fed with high-fat diet,and effectively protect liver histomorphology and function.This may be partly explained by increased AMPK expression in liver.Therefore,Dan-gua Fang might be an ideal drug for comprehensive Intervention for glucose and lipid metabolism disorders in type 2 diabetes mellitus.

Gypenoside ameliorates insulin resistance and hyperglycemia via the AMPK-mediated signaling pathways in the liver of type 2 diabetes mellitus mice

Gynostemma pentaphyllum,also called"Southern Ginseng"in China,is a traditional Asian folk medicinal plant.Gypenosides(Gps)are the biologically active constituents of G.pentaphyllum,which have been reported with hypoglycemic activity.However,the underlying mechanisms are unclear.The effects of two Gps(Gp-Ⅰand Gp-Ⅱ)on type 2 diabetic mellitus(T2DM)mice,induced by high-fat and high-sugar diet and streptozotocin,were evaluated to explore the mechanism of their hypoglycemic actions.Gps reduced fasting blood glucose and serum lipids,as well as significantly improved T2DM mice glucose tolerance and insulin resistance(IR).After Gps treatment,the severity of liver injury was reduced and liver glycogen content increased.In addition,Gps promoted the phosphorylation of adenosine monophosphate-activated protein kinase(AMPK),and downregulated the key proteins phosphoenolpyruvate carboxy kinase and glucose-6 phosphatase,in the AMPK signaling pathway.Thus,our study suggests that Gps mediate hepatic gluconeogenesis and improve IR via activating AMPK signaling pathway in T2DM mice.

Inflammatory myofibroblastic tumor successfully treated with metformin: A case report and review of literature

BACKGROUND Inflammatory myofibroblastic tumor(IMT)is a distinct tumor with a low incidence rate,which can be diagnosed at any age with a predilection for children and adolescents.Although IMT is visible in any tissues and organs,it is more commonly found in the lungs.The clinical and radiological manifestations of IMT lack specificity,hence resulting in frequent misdiagnosis.Surgical resection is currently the main therapeutic approach for IMT.Only scarce cases of IMT treated with metformin have been reported.Here we report the case of an IMT patient with partial penile resection treated with metformin.CASE SUMMARY A 1-year-old boy was born with a shorter penis,and his foreskin could not be completely turned over.When he was 6 month old,a well-circumscribed mass on the glans was found,while it did not attract the attention of his parents.The mass gradually increased in size over time before he was admitted to the hospital,where physical examination was performed.It was revealed that the glans hidden behind the foreskin had a mass with a diameter of about 4 cm surrounding the penis.The mass appeared to be hard with a smooth surface and poor mobility.The two testicles examined at the bottom of the scrotum were revealed to have a normal size.Magnetic resonance imaging showed a tumor with rich blood supply encircling the cavernosum with a size of 3.5 cm×2.1 cm×2.0 cm.A thick urinary line was found without urine dripping,urgency,and urodynia.Surgical treatment was performed.During the operation,it was observed that the mass had surrounded and invaded the cavernosum without obvious boundaries,and that the tumor occupied about one-half of the penis cross-section as well as infiltrated more than one-half of the glans.In addition,the tumor had caused urethral invasion and anterior urethrostenosis.With the intention of keeping the glans and cavernosum,the tumor at the anterior urethra was partially removed,leaving about 30%of the tumor mass.Pathology analysis demonstrated that the tumor was rich in spindle cells with infiltration of inflammatory cells.Immunohistochemistry analysis indicated that the cells were positive for CD4,CD99,Ki67,BCL2,and CD68,and negative for ALK,MyoG,S100,SOX10,PR,and EMA.Hence,the tumor was diagnosed as IMT.Metformin was prescribed for the patient after the operation,following which an oral dose of 7 mg/kg was given three times a day after meals.Three months later,it was observed that the remaining tumor had completely disappeared and that the urination process from the urethra opening had resumed normal.In addition,there were no side effects observed.There was also no tumor recurrence.The growth and development of the boy were unaffected as a result of the treatment.CONCLUSION The tumor was observed to have completely disappeared after treatment with metformin.Our finding is of great significance to facilitate future clinical treatment with IMT.

AMPK Subunit Expression Regulates Intramuscular Fat Content and Muscle Fiber Type in Chickens

The objective of this study was to assess the role of AMPK in intramuscular fat(IMF) and fiber type in chicken muscle. The chickens were slaughtered and their muscles were collected at the ages of 4, 8, and 16 weeks so as to determine the IMF contents, as well as the expression levels of AMPK subunits, regulators of adipogenesis. In addition, the myosin heavy chains(My HCs) in thigh muscle tissues were also measured. The results showed that the IMF contents in 16-week old chickens were higher than those in 4 and 8-week-old chickens(P<0.05).The expression levels of fatty acid synthase(FAS) and fatty aicd translocase CD36(FAT/CD36) m RNA were increased significantly in samples collected at the ages of4 and 16 weeks(P<0.05). The expression levels of My HC IIa and IIb differed significantly among all the developmental stages(P <0.05). The AMPKα2, AMPKγ1,and AMPKγ3 m RNA levels were dramatically decreased with the increase of age(P <0.05). To examine the role of AMPK in adipogenesis regulation, the SV cells were cultured in an adipogenesis medium and treated with AICAR and Compound C respectively, the specific activator and inhibit of AMPK. The Compound C induced dramatically a greater expression of C/EBPβ, SREBP1 and PPARγ(P <0.05). In conclusion, the expression of AMPKα2, AMPKγ1, and AMPKγ3 m RNA is significantly correlated with the adipogenesis in skeletal muscle of chickens.

Regulatory effects of anandamide on intracellular Ca^(2+) concentration increase in trigeminal ganglion neurons

Activation of cannabinoid receptor type 1 on presynaptic neurons is postulated to suppress neu- ~ ~ ~ 2＋ ~ ~ 2＋ rotransmlsslon by decreasing Ca reflux through high voltage-gated Ca channels. However, recent studies suggest that cannabinoids which activate cannabinoid receptor type 1 can increase neurotransmitter release by enhancing Ca2＋ influx in vitro. The aim of the present study was to investigate the modulation of intracellular Ca2＋ concentration by the cannabinoid receptor type 1 agonist anandamide, and its underlying mechanisms. Using whole cell voltage-damp and calcium imaging in cultured trigeminal ganglion neurons, we found that anandamide directly caused Ca2＋ influx in a dose-dependent manner, which then triggered an increase of intracellular Ca2＋ concentration. The cyclic adenosine and guanosine monophosphate-dependent protein kinase systems, but not the protein kinase C system, were involved in the increased intracellular Ca2＋concentration by anandamide. This result showed that anandamide increased intracellu- lar Ca2＋ concentration and inhibited high voltage-gated Ca2＋ channels through different signal transduction pathways.

Adenosine Monophosphate-Activated Protein Kinase,Oxidative Stress,and Diabetic Endothelial Dysfunction

Endothelial dysfunction characterized by impaired endothelium-dependent vaso-relaxation is one of the earliest detectable pathological events in smoking,diabetes,and many cardiovascular diseases including hypertension,atherosclerosis.Overwhelming data from human and animals demonstrate that the endothelial dysfunction associated with diabetes is due to the local formation of oxidants and free radicals.However,the mechanisms by which diabetes instigates oxidative stress,and those by which oxidative stress perpetuates endothelial dysfunction are the subjects of intensive research in the last 3 decades.The studies from us and others have demonstrated that adenosine monophosphate-activated protein kinase(AMPK),a well-characterized energy sensor and modulator,serves as a highly efficient sensor as AMPK can be activated by very low levels of reactive oxygen species(ROS)and reactive nitrogen species(RNS)generated by physiological,pharmacological,and pathologic stimuli(redox sensor).Interestingly,oxidants-activated AMPK feedback lowers the levels of ROS by either suppressing ROS/RNS from reduced nicotinamide adenine dinucleotide phosphate(NADPH)oxidase and mitochondria or by increasing the levels of antioxidant enzymes(redox modulator).Further,our studies demonstrate that AMPK’s functions as a redox sensor and modulator are vital to maintain endothelial cell function under physiological conditions.Finally,we discover that under chronic oxidative stress or large influx of ROS,AMPK is particularly susceptible to inhibition by ROS.We conclude that oxidative inactivation of AMPK in diabetes perpetuates oxidative stress and accelerates atherosclerosis in diabetes.

Too hard to die:Exercise training mediates specific and immediate SARS-CoV-2 protection

Several mechanisms may explain how exercise training mechanistically confers protection against coronavirus disease 2019(COVID-19).Here we propose two new perspectives through which cardiorespiratory fitness may protect against severe acute respiratory syndrome coronavirus-2(SARS-CoV-2).Physical exercise-activated adenosine monophosphate(AMP)-activated protein kinase(AMPK)signaling induces endothelial nitric oxide(NO)synthase(eNOS),increases NO bio-availability,and inhibits palmitoylation,leading to specific and immediate SARS-CoV-2 protection.AMPK signaling also induces angiotensin 1-7 release and enhances eNOS activation thus further mediating cardio-and renoprotection.Irisin,a myokine released from skeletal muscles during aerobic exercise,also participates in the AMPK/Akt-eNOS/NO pathway,protects mitochondrial functions in endothelial cells,and antagonizes renin angiotensin system proinflammatory action leading to reductions in genes associated with severe COVID-19 outcomes.Collectively,all the above findings point to the fact that increased AMPK and irisin activity through exercise training greatly benefits molecular processes that mediate specific,immediate,and delayed SARS-CoV-2 protection.Maintaining regular physical activity levels is a safe and affordable lifestyle strategy against the current and future pandemics and may also mitigate against obesity and cardiometabolic disease syndemics.Move more because a moving target is harder to kill.