CHANGES IN NEUROPEPTIDES AFTER MUSIC EXPOSURE 429Cardioprotective effect of ivabradine via the AMPK/SIRT1/PGC-1αsignaling pathway in myocardial ischemia/reperfusion injuryinduced in H9c2 cell

Post-resuscitation myocardial dysfunction(PRMD)is the most severe myocardial ischemia-reperfusion injury(MIRI)and is characterized by difficult treatment and poor prognosis.Research has shown the protective effects of the rational use of ivabradine(IVA)against PRMD,however,the molecular mechanisms of IVA remain unknown.In this study,an ischemia-reperfusion injury(IRI)model was established using hypoxic chambers.The results demonstrated that pretreatment with IVA reduced IRI-induced cytotoxicity and apoptosis.IVA attenuated mitochondrial damage,eliminated excess reactive oxygen species(ROS),suppressed IRI-induced ATP and NAD+,and increased the AMP/ATP ratio.We further found that IVA increased the mRNA levels of sirtuin 1(SIRT1)and peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α)and upregulated the expression levels of phosphorylated AMP-activated protein kinase(p-AMPK)/AMPK,SIRT1,and PGC-1αproteins.Interestingly,no change in AMPK mRNA levels was observed.Cardiomyocyte energy metabolism significantly changed after IRI.The aim of this study was to demonstrate the cardioprotective effect of Ivabradine via the AMPK/SIRT1/PGC-1αsignaling pathway in myocardial ischemia/reperfusion injury-induced in H9c2 cell.

Yiqi Yangyin and Huatan Quyu granule can improve skeletal muscle energy metabolism in a type 2 diabetic rat model by promoting the AMPK/SIRT/PGC-1α signalling pathway

Objective:To investigate how Yiqi Yangyin and Huatan Quyu granule (YYHO) improves skeletal muscle insulin resistance in a type 2 diabetic rat model and to discover whether the molecular mechanism is related to the promotion of the AMPK/SIRT/PGC-1α signalling pathway.Methods:Rats were randomly divided into 4 groups:the normal group,the model group,the YYHQ granule group,and the pioglitazone group.The type 2 diabetic rat model was established by feeding a high-fat diet for 5 weeks along with a single intraperitoneal injection of 30 mg/kg streptozotocin (STZ).After modelling successfully,the appropriate drug was intragastrically administered to diabetic rats for 2 weeks,once per day.The YYHQ granule group was given a dose of 4.8 g/kg body weight per day,the pioglitazone group was given a dose of 1.35 mg/kg body weight per day.The doses for both groups were equivalent to the clinical equivalent dose based on a previous study.Other groups were gavaged with the same amount of saline water.Body weight,food intake,water intake,urine volume and grip strength were recorded weekly.The fasting blood glucose(FBG) was determined weekly using blood glucose test strips.The related glucose and lipid metabolism indexes,e.g.,fasting insulin (Fins),glycated haemoglobin (GHb),HOMA-IR,ISI,triglycerides (TG),total cholesterol (TC),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C) and free fatty acid (FFA),were determined using biochemical method.The mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK),peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α),carnitine palmitoyl transterase-1 (CPT-1),Sirtuin 1 (SIRT1),and Sirtuin 3 (SIRT3) were assessed using quantitative real-time PCR (qRT-PCR).The protein expression levels of creatine kinase (CK),Ca2+ ATPase,α-Actin,AMPK,PGC-1α and CPT-1 were determined using enzyme-linked immunosorbent assay method (ELISA).Results:Body weight decreased significantly (P <.01),food intake,water intake and urine volume increased significantly (P <.01),and grip strength decreased significantly (P <.01) in the model group compared with the normal group.The levels of FBG,Fins,GHb and HOMA-IR increased significantly (P <.01),and the ISI decreased significantly (P <.01) in the model group.The levels of TG,TC,LDL-C and FFA increased significantly (P <.05 or P <.01),and the level of HDL-C decreased significantly (P <.05) in the model group.These changes were reversed after treatment with YYHQ granule or pioglitazone.Compared with the model group,the YYHQ granule and pioglitazone groups significantly improve body weight,water intake and urine volume (P <.05 or P <.01),however,both treatments had no significant effect on food intake (P >.05).The levels of FBG,Fins,GHb,HOMA-IR and ISI were improved significantly (P <.01) and the levels of TG,TC and LDL-C were improved significantly (P <.05 or P <.01),however,both treatments had no significant effect on the levels of HDL-C and FFA (P >.05).Further results indicated that YYHQ granule significantly decreased the mRNA expression of AMPK,PGC-1α,CPT-1,SIRT1 and SIRT3 in skeletal muscle (P <.01) and the pioglitazone group showed similar effects;moreover,the protein expression levels of CK,Ca2+ATPase,α-Actin,AMPK,PGC-1α and CPT-1 in skeletal muscle significantly decreased (P <.01),however,pioglitazone had no significant effect on CK and α-Actin (P >.05).Conclusion:The possible molecular mechanism of YYHQ granule improving skeletal muscle insulin resistance in a type 2 diabetic rat model may be related to the stimulation of energy metabolism in skeletal muscle via the AMPK/SIRT/PGC-1α signalling pathway.

Electroacupuncture improves cognitive function in a rat model of mild traumatic brain injury by regulating the SIRT-1/PGC-1α/mitochondrial pathway

Background:Mild traumatic brain injury(mTBI)is a common neurological trauma that can lead to cognitive impairment.The sirtuin-1(SIRT-1)/peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α)pathway has been reported to have neuroprotective effects in rats with craniocerebral injury.We evaluated potential mechanisms underlying electroacupuncture-mediated recovery of cognitive function after mTBI,focusing on the SIRT-1/PGC-1α/mitochondrial pathway.Methods:We included forty 6-week-old male Sprague-Dawley rats in this study.Rats were randomly divided into four groups:controlled cortical impactor(CCI,n=10),sham operation(sham,n=10),electroacupuncture-treated CCI(CCI+EA,n=10),and electroacupuncture-treated sham(sham+EA,n=10)group.Randomization was performed by assigning a random number to each rat and using a random number table.The mTBI rat model was established using a controllable cortical impactor.Electroacupuncture therapy was performed on the back of rats,by inserting acupuncture needles to the specific acupoints and setting appropriate parameters for treatment.We evaluated spatial learning and memory functions with the Morris water maze test.We performed quantitative real-time polymerase chain reaction(qRT-PCR),western blotting,adenosine triphosphate(ATP)determination,and mitochondrial respiratory chain complex I(MRCC I)determination on rat hippocampal tissue.We analyzed SIRT-1/PGC-1α expression levels and the results of mitochondrial function assays,and compared differences between groups using bilateral Student’s t-tests.Results:Compared with the sham group,SIRT-1/PGC-1α expression was downregulated in the hippocampus of CCI group(P<0.01).Although this expression was upregulated following electroacupuncture,it did not reach the levels observed in the sham group(P<0.05).Compared with the sham group,MRCC I and ATP levels in the CCI group were significantly reduced,and increased after electroacupuncture(P<0.01).In the Morris water maze,electroacupuncture reduced the incubation period of rats and increased average speed and number of crossing platforms(P<0.05).Conclusion:Electroacupuncture may improve cognitive function in the mTBI rat model by regulating the SIRT-1/PGC-1α/mitochondrial pathway.

Anti-fatigue activity and mechanism of crocetin loaded nanoliposome in acute exercise-treated mice

Crocetin displays strong antioxidant,anti-inflammatory and anti-depression activity which is promising to relieve symptoms of fatigue.As a carotenoid,crocetin is difficult to dissolve in water and highly unstable against many environmental factors.Nanoliposome is used to encapsulate crocetin to improve its water dispersion.In the present study,the antifatigue activities and potential mechanism of crocetin loaded nanoliposome(CLN)was extensively investigated.The potential antifatigue pathway of CLN was analyzed.Furthermore,impact of CLN on the gut microbiota structure was examined which contributes to its antifatigue functions.CLN significantly increases exhaustive swimming time of fatigue mice,decreases the blood contents of lactic,blood urea nitrogen(BUN)and malondialdehyde(MDA).At the same time,CLN improves the activity of glutathione peroxidase(GSH-Px)and succinate dehydrogenase(SDH)enzyme,attenuates the oxidant stress in mice.CLN activates the adenosine monophosphate-activated kinase(AMPK)/peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α)signaling pathway of fatigue mice,increases the mRNA expression of ATP synthase.It also increases mRNA expression of mitochondrial transcription factor A(TFAM)which promotes mitochondrial biogenesis.Additionally,CLN ameliorates the gut microbiota structure by increasing the abundance of genus such as Lactobacillus in fatigue mice.In summary,CLN exerts strong anti-fatigue properties by decreasing the oxidant stress and the contents of harmful metabolites,augmenting the production of ATP,and potentially ameliorating the gut microbiota structure.