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ObjectiveTo investigate the effect of Gegen Qinliantang on glucose and lipid metabolism in the rat model of catch-up growth (CUG) induced by a high-fat diet and the underlying mechanism. MethodA total of 60 SD rats were randomized into a normal control group (n=18) and a modeling group (n=42). The rat model of CUG was established with a restricted diet followed by a high-fat diet, and the changes of general status and body weight were observed. The levels of fasting blood glucose (FBG), fasting insulin (FINS), triglyceride (TG), and total cholesterol (TC) were measured in 6 rats in each group at the end of the 4th and 8th week, respectively. The homeostasis model assessment of insulin resistance index (HOMA-IR) was calculated, and the insulin sensitivity and body composition changes of CUG rats were evaluated. The successfully modeled rats were assigned into 6 groups: normal control, model, high-, medium-, and low-dose Gegen Qinliantang (2.5, 5, 10 g·kg-1), and pioglitazone (3.125 mg·kg-1). The rats were administrated with corresponding drugs by gavage for 6 weeks, and the normal control group and model group were administrated with the same amount of normal saline. During the experiment period, the changes of body weight were recorded, and the FBG, FINS, HOMA-IR, TG, and TC were determined at the end of the experiment. Hematoxylin-eosin (HE) staining was employed to observe the pathological changes of skeletal muscle in rats. The levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in the skeletal muscle were measured strictly according to the manuals of the reagent kits. Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) was performed to measure the mRNA levels of silencing information regulator 1 (SIRT1), peroxisome proliferator-activated receptor-gamma coactivator1α (PGC1α), and nuclear respiratory factor 1 (Nrf1) in the skeletal muscle. Western blot and immunohistochemistry were employed to assess the expression of SIRT1, PGC1α, and Nrf1 in the skeletal muscle. ResultCompared with the normal control group, the model group presented elevated levels of FBG, FINS, TG, and TC (P<0.05, P<0.01), increased HOMA-IR (P<0.01), increased diameter of muscle fibers and adipocytes between muscle cells in the skeletal muscle, rising levels of ROS and MDA in the skeletal muscle (P<0.01), and down-regulated mRNA and protein levels of SIRT1, PGC1α, and Nrf1 (P<0.05, P<0.01). Compared with the model group, Gegen Qinliantang (especially the medium and high doses) and pioglitazone decreased the body weight, FINS, HOMA-IR, and TG (P<0.05, P<0.01) and reduced interstitial components such as intermuscular fat in the skeletal muscles and the diameter of muscle fibers. Furthermore, the drugs lowerd the levels of ROS and MDA (P<0.05, P<0.01) and up-regulated the mRNA and protein levels of SIRT1, PGC1α, and Nrf1 (P<0.05, P<0.01) in the skeletal muscle. ConclusionGegen Qinliantang can ameliorate the glucose and lipid metabolism disorders and insulin resistance in CUG rats by regulating the SIRT1/PGC1α/Nrf1 signaling pathway.
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ObjectiveTo investigate the effect and mechanism of total saponins from Panax japonicus (TSPJ) on white adipose tissue (WAT) browning/brown adipose tissue (BAT) activation in C57BL6/J male mice fed on a high-fat diet (HFD). MethodThirty-two C57BL6/J male mice (8-week-old) were randomly divided into a normal group, a model group, a low-dose TSPJ group, and a high-dose TSPJ group. The mice in the low-dose and high-dose TSPJ groups were given TSPJ for four months by gavage at 25, 75 mg·kg-1·d-1, respectively, and those in the other groups were given 0.5% sodium carboxymethyl cellulose (CMC-Na) accordingly. After four months of feeding, all mice were placed at 4 ℃ for acute cold exposure, and the core body temperature was monitored. Subsequently, all mice were sacrificed, and BAT and inguinal WAT (iWAT) were separated rapidly to detect the corresponding indexes. Hematoxylin-eosin (HE) staining was used to observe the morphological changes in each group. The effect of TSPJ on the mRNA expression of uncoupling protein 1 (UCP1), fatty acid-binding protein 4 (FABP4), cytochrome C (CytC), PR domain-containing protein 16 (PRDM16), elongation of very long chain fatty acids protein 3 (ELOVL3), peroxisome proliferator-activated receptor γ (PPARγ), and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) in iWAT and BAT was detected by Real-time polymerase chain reaction (Real-time PCR). Western blot was also used to detect the protein expression of UCP1, PRDM16, PPARγ, and PGC-1α in BAT and iWAT of each group. The effect of TSPJ on UCP1 expression in BAT and iWAT was detected by immunohistochemistry. Result① Compared with the model group, TSPJ could decrease the body weight and proportions of iWAT and BAT in the HFD-induced mice (P<0.05, P<0.01). ② The body temperature of mice in the model group decreased compared with that in the normal group in the acute cold exposure tolerance test (P<0.05). The body temperature in the high-dose TSPJ group increased compared with that in the model group (P<0.01). ③ Compared with the normal group, the model group showed increased adipocyte diameter in iWAT and BAT and decreased number of adipocytes per unit area. Compared with the model group, the TSPJ groups showed significantly reduced cell diameter and increased number of cells per unit area, especially in the high-dose TSPJ group. ④ Compared with the normal group, the model group showed decreased mRNA expression of FABP4, UCP1, CytC, PRDM16, ELOVL3, PGC-1α, and PPARγ in adipose tissues of mice (P<0.05, P<0.01). Compared with the model group, after intervention with TSPJ, the mRNA expression was significantly up-regulated (P<0.05, P<0.01). ⑤ Compared with the normal group, the model group showed decreased protein expression of UCP1, PRDM16, PPARγ, and PGC-1α in adipose tissues of mice (P<0.05, P<0.01). Compared with the model group, after intervention with TSPJ, the protein expression increased significantly (P<0.05, P<0.01). ConclusionTSPJ could induce the browning of iWAT/BAT activation and enhance adaptive thermogenesis in obese mice induced by HFD. The underlying mechanism may be attributed to the activation of the PPARγ/PGC-1α signaling pathway.
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ObjectiveTo investigate the effect of Tangbikang granules on oxidative stress of sciatic nerve in diabetic rats by regulating adenylate activated protein kinase/peroxisome proliferator-activated receptor γ coactivator-1α/mitochondrial Sirtuins 3 (AMPK/PGC-1α/SIRT3) signaling pathway. MethodThe spontaneous obesity type 2 diabetes model was established using ZDF rats. After modeling, they were randomly divided into high, medium, and low dose Tangbikang granule groups (2.5, 1.25, 0.625 g·kg-1·d-1) and lipoic acid group (0.026 8 g·kg-1·d-1), and the normal group was set up. The rats were administered continuously for 12 weeks after modeling. The blood glucose of rats was detected before intervention and at 4, 8, 12 weeks after intervention. At the 12th week, motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNCV), nerve blood flow velocity, mechanical pain threshold, and thermal pain threshold were detected. The sciatic nerve was taken for hematoxylin-eosin (HE) staining to observe the tissue morphology. The ultrastructure of the sciatic nerve was observed by transmission electron microscope. The expression levels of superoxide dismutase (SOD), malondialdehyde (MDA), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in sciatic nerve were determined by enzyme-related immunosorbent assay (ELISA). The mRNA expressions of AMPKα, AMPKβ, PGC-1α, and SIRT3 in sciatic nerve were determined by real-time polymerase chain reaction (Real-time PCR). ResultCompared with the normal group, fasting blood glucose in the model group was increased at each time point (P<0.01). The mechanical pain threshold was decreased (P<0.05), and the incubation time of the hot plate was extended (P<0.01). MNCV, SNCV, and nerve blood flow velocity decreased (P<0.05). The expression level of SOD was decreased (P<0.01). The expression levels of MDA, IL-1β, and TNF-α were increased (P<0.01). The mRNA expression levels of AMPKα, AMPKβ, PGC-1α, and SIRT3 were decreased (P<0.01). The structure of sciatic nerve fibers in the model group was loose, and the arrangement was disordered. The demyelination change was obvious. Compared with the model group, the fasting blood glucose of rats in the high dose Tangbikang granule group was decreased after the intervention of eight weeks and 12 weeks (P<0.01). The mechanical pain threshold increased (P<0.05). The incubation time of the hot plate was shortened (P<0.01). MNCV, SNCV, and Flux increased (P<0.05). The expression level of SOD was increased (P<0.01). The expression levels of MDA, IL-1β, and TNF-α were decreased (P<0.01). The mRNA expression levels of AMPKα, AMPKβ, PGC-1α, and SIRT3 were increased (P<0.01). The sciatic nerve fibers in the high-dose Tangbikang granule group were tighter and more neatly arranged, with only a few demyelinating changes. The high, medium, and low dose Tangbikang granule groups showed a significant dose-effect trend. ConclusionTangbikang granules may improve sciatic nerve function in diabetic rats by regulating AMPK/PGC-1α/SIRT3 signaling pathway partly to inhibit oxidative stress.
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Background The pathogenesis of silicosis is complex and treatment methods are limited. SiO2-induced increase of transforming growth factor-β1 (TGF-β1) can activate fibroblasts to promote collagen deposition, ultimately leading to fibrosis. Previous studies have confirmed that lipid metabolism plays an important role in the progression of silicosis. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) mediates mitochondrial dysfunction and lipid metabolism pathways in diabetic models, but its role in silicosis has not been elucidated. Objective To investigate the effect of PGC1α on lipid metabolism disorder of macrophages induced by SiO2 and its effect on the progression of silicosis fibrosis. Methods (1) Macrophages were divided into four groups by transfecting and silencing PGC1α and its control sequence in macrophages and followed by SiO2 stimulation: negative control group (transfected with si-NC for 48 h), si-PGC1α group (transfected with si-PGC1α for 48 h), SiO2 stimulation group (stimulated with 50 μg·mL−1 SiO2 for 36 h after transfection with si-NC for 48 h), and si-PGC1α+SiO2 group (stimulated with 50 μg·mL−1 SiO2 for 36 h after transfection with si-PGC1α for 48 h). Western blot and cell immunofluorescence were used to test PGC1α expression, 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY 493/503) and total cholesterol (TC) and free cholesterol (FC) kits were used to test lipid accumulation, and the Oroboros2k-Oxygraph respiratory test system (O2K) was used to assess the effects of PGC1α on mitochondrial respiratory chain. ELISA kits were used to test TGF-β1 expressed in the macrophage supernatant. (2) Lung fibroblasts were divided into the same four groups as above, and stimulated with the supernatant of macrophages in the above groups. The expression of collagen Ι (COL Ι), E-cadherin (Eca), and fibronectin (FN) were detected by cell immunofluorescence and Western blot to further evaluate the effect of silencing PGC1α on fibrosis. Results The protein expression level of PGC1α stimulated by SiO2 was decreased, and the relative expression level of PGC1α was 0.78 times that of the control group (P<0.05). After transfection with si-PGC1α, the expression of PGC1α was decreased, and the relative protein expression level of the si-PGC1α group was 0.86 times that of the control group (P<0.05). Compared with the SiO2 stimulation group, the staining area of BODIPY 493/503 in the si-PGC1α+SiO2 group was enhanced, and the cholesterol-related indexes [TC, FC and cholesterol ester (CE)] were increased to 1.38, 1.10, and 2.26 times those in the SiO2 stimulation group (P<0.05). The activity of mitochondrial complex Ι was decreased, and the level of complex Ι in the si-PGC1α+SiO2 group was 0.63 times that in the SiO2 stimulation group (P<0.05). The secretion of TGF-β1 by macrophages increased, and the level of TGF-β1 in the si-PGC1α+SiO2 group was 1.15 times that of the SiO2 stimulation group (P<0.05). In addition, after stimulation of primary lung fibroblasts with macrophage supernatant, silencing PGC1α increased the expression levels of COL Ι and FN, while decreased the expression of Eca. The protein levels of COL Ι, FN, and Eca in the si-PGC1α+SiO2 group were 1.39, 1.18, and 0.82 times those in the SiO2 stimulation group, respectively (P<0.05). Conclusion Silencing PGC1α exacerbates SiO2-induced lipid metabolism disorder, inhibits mitochondrial respiratory chain, and aggravates the fibrosis induced by SiO2, suggesting that PGC1α may participate silicosis fibrosis by regulating mitochondrial respiratory chain and lipid metabolic disorder induced by SiO2.
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ObjectiveTo observe the effect of salvianolate on the protein expressions of adenosine monophosphate (AMP)-activated protein kinase (AMPK), silent information regulator 1 (SIRT1) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), autophagy and apoptosis in kidney tissue of rats with membranous nephropathy (MN), and to explore its possible molecular mechanism against MN. MethodEighty male SD rats were randomly divided into normal group, model group, benazepril hydrochloride group (10 mg·kg-1), and salvianolate low-, medium-, and high-dose groups (16.7, 33.3 and 66.7 mg·kg-1). The rats were modeled by injection of cationized bovine serum albumin (C-BSA) into the tail vein. After successful modeling, rats in the administration groups were given corresponding doses of drugs for 4 consecutive weeks, and then 24-hour urine, serum and kidney tissue were collected for the detection of 24-hour urinary protein (UTP), blood urea nitrogen (BUN), serum creatinine (SCr), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C reactive protein (CRP), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and malondialdehyde (MDA). The pathological changes of kidneys were observed by light microscope, electron microscope and immunofluorescence. Western blot was used to detect the protein expressions of phospho-AMPK (p-AMPK), AMPK, phospho-SIRT1 (p-SIRT1), SIRT1 and PGC-1α in rat kidney tissue. The protein expressions of autophagy-specific gene (Beclin-1), microtubule-associated protein 1 light chain 3 (LC3) Ⅱ, ubiquitin-binding protein (p62), B cell lymphoma (Bcl-2), Bcl-2-associated X (Bax), and cysteine aspartic protease-7 (Caspase-7) in rat kidney tissue were determined by immunohistochemistry (IHC). ResultCompared with the conditions in the normal group, the levels of UTP, IL-6, TNF-α, CRP and MDA in the model group were increased (P<0.05) while the levels of SOD and GSH-Px were decreased (P<0.05), and there was no difference in BUN and SCr. Compared with the model group, the administration groups had lowered UTP, IL-6, TNF-α, CRP and MDA (P<0.05) while elevated SOD and GSH-Px (P<0.05). It could be seen from hematoxylin and eosin (HE) staining, Masson staining, immunofluorescence and electron microscopy that the pathological damage of rat kidney tissue in the model group was significant, but after treatment with benazepril hydrochloride and salvianolate, the pathological damage of kidney cells was gradually improved. The expressions of p-AMPK/AMPK, p-SIRT1/SIRT1, PGC-1α, Bcl-2, Beclin-1 and LC3Ⅱ in rat kidney in the model group were lower than those in the normal group (P<0.05) while the expressions of Bax, Caspase-7 and p62 were higher (P<0.05). Compared with the model group, benazepril hydrochloride group and salvianolate groups had an up-regulation in the expressions of p-AMPK/AMPK, p-SIRT1/SIRT1, PGC-1α, Bcl-2, Beclin-1 and LC3Ⅱ in the kidney (P<0.05) while a down-regulation in the expressions of Bax, Caspase-7 and p62 (P<0.05). ConclusionThe protective effect of salvianolate on the kidneys of MN rats may be related to the activation of AMPK/SIRT1/PGC-1α signaling pathway, the up-regulation of autophagy and the reduction of apoptosis.
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Objective:To investigate the protective mechanism of remote ischemic preconditioning (RIPC) on cerebral ischemia-reperfusion (I/R) injury in rats.Methods:Forty-eight SD rats were randomly divided into sham operation group, RIPC group, I/R group, RIPC+I/R group, and compound C group ( n=9 in each group). The neurological function score, cerebral infarction volume (TCC staining) and neuronal apoptosis rate (TUNEL staining) were measured. The activity of superoxide dismutase (SOD) 2 and malondialdehyde level in homogenate of brain tissue were detected. Expression levels of AMP-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α signaling pathway-related proteins in brain tissue were detected by Western blot. Results:The neurological deficit score, cerebral infarction volume and neuron apoptosis rate in the I/R group were significantly higher than those in the sham operation group (all P<0.05). Compared with the I/R group, the neurological deficit score, cerebral infarction volume and neuron apoptosis rate in the RIPC+I/R group were significantly decreased (all P<0.05). Compared with the RIPC+I/R group, the neurological deficit score, cerebral infarction volume and neuron apoptosis rate in the compound C group were significantly increased (all P<0.05). Compared with the sham operation group, the SOD activity in the I/R group was significantly decreased, and the malondialdehyde content was significantly increased (all P<0.05). Compared with the I/R group, the SOD activity in the RIPC+I/R group was significantly increased, and the malondialdehyde content was significantly decreased (all P<0.05). Compared with the RIPC+I/R group, the SOD activity in the compound C group was significantly decreased, and the malondialdehyde content was significantly increased (all P<0.05). Compared with the sham operation group, the expressions of AMPK, p-AMPK, PGC-1α, nuclear respiratory factor (NRF)-1, mitochondrial transcription factor A (TFAM), SOD2, uncoupling protein 2 (UCP2), cytochrome C (CytC), and apoptosis-inducing factor (AIF) in the brain tissue of the I/R group were significantly increased (all P<0.05). Compared with the I/R group, the expressions of AMPK, p-AMPK, PGC-1α, NRF-1, TFAM, SOD2 and UCP2 in the ischemic brain tissue of the RIPC+I/R group were significantly increased, while the expressions of CytC and AIF were significantly decreased (all P<0.05). Compared with the RIPC+I/R group, the expressions of AMPK, p-AMPK, PGC-1α, NRF-1, TFAM, SOD2 and UCP2 in the brain tissue of the compound C group were significantly decreased, while the expressions of CytC and AIF were significantly increased (all P<0.05). Conclusions:RIPC has a protective effect on I/R injury. Its mechanism may be associated with the activation of AMPK/PGC-1α signaling pathway and maintaining mitochondrial biogenesis.
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ObjectiveTo reveal the effect of Wenxin prescription on mitochondrial energy metabolism and silent information regulator 1 (SIRT1)/peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α)/recombinant estrogen-related receptor α (ERRα) signaling pathway in rats with myocardial ischemia-reperfusion injury. MethodTotally 90 male Wistar rats of SPF grade were randomly assigned into a sham operation group, a model group, and low-, medium-, and high-dose Wenxin prescription groups, with 18 rats in each group. The rats in low-, medium-, and high-dose Wenxin prescription groups were administrated with 0.99, 1.98, and 3.96 g·kg-1 granules by gavage, respectively, and those in the sham operation group and model group with the same amount of normal saline. Twenty-one days after pre-administration, the rat model of myocardial ischemia-reperfusion injury was established by ligation of the left anterior descending coronary artery for 30 min and reperfusion for 2 h, and the rats in the sham operation group were only threaded without ligation. Myocardial infarction area was observed through 2,3,5-triphenyl-2h-tetrazolium chloride (TTC) staining, and the myocardial histopathology through hematoxylin-eosin (HE) staining. The levels of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) in serum, cytochrome C oxidase (CCO) and succinate dehydrogenase (SDH) in mitochondrion, and ATP in myocardial tissue were detected according to kit instructions. The mRNA and protein levels of SIRT1, PGC-1α, ERRα, and mitochondrial transcription factor A (TFAM) in myocardial tissue were determined by Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) and Western blot, respectively. ResultCompared with the sham operation group, the model group showed broken and disordered myocardial fibers, cytoplasmic edema, and pyknosis and deviation of nuclei. Moreover, the modeling increased the levels of CK-MB and LDH (P<0.05, P<0.01), lowered the levels of ATP, CCO, and SDH (P<0.05, P<0.01), and down-regulated the mRNA and protein levels of SIRT1, PGC-1α, ERRα, and TFAM in myocardial tissue (P<0.05, P<0.01). Compared with the model group, Wenxin prescription reduced the myocardial infarction area (especially in the high-dose group, P<0.01), restored the pathological changes, lowered the levels of CK-MB and LDH (P<0.05, P<0.01), increased the levels of ATP, CCO, and SDH (especially in the high-dose group, P<0.01), and up-regulated the mRNA and protein levels of SIRT1, PGC-1α, ERRα, and TFAM in myocardial tissue (P<0.05, P<0.01). ConclusionWenxin prescription can protect rats from myocardial ischemia-reperfusion injury by regulating myocardial mitochondrial energy metabolism via the SIRT1/PGC-1α/ERRα signaling pathway.
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OBJECTIVE@#To investigate the cardioprotective effect of Danqi Tablet (DQT, ) on ischemic heart model rats and the regulative effect on energy metabolism through peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α).@*METHODS@#Rat ischemic heart model was induced by ligation of left anterior descending coronary artery. Totally 40 Sprague-Dawley rats were randomly divided into sham group, model group, DQT group (1.5 mg/kg daily) and trimetazidine (TMZ) group (6.3 mg/kg daily) according to a random number table, 10 rats in each group. Twenty-eight days after continuous administration, cardiac function was assessed by echocardiography and the structures of myocardial cells were observed by hematoxylin-eosin staining. The level of adenosine triphosphate (ATP) in myocardial cells was measured by ATP assay kit. Expressions level of key transcriptional regulators, including PGC-1α, Sirtuin 1 (SIRT1), AMP-activated protein kinase (AMPK), and downstream targets of PGC-1α, such as mitofusin 1 (MFN1), mitofusin 2 (MFN2) and superoxide dismutase 2 (SOD2) were measured by Western blot. Expression level of PGC-1α was examined by immunohistochemical staining.@*RESULTS@#The rat ischemic heart model was successfully induced and the heart function in model group was compromised. Compared with the model group, DQT exerted cardioprotective effects, up-regulated the ATP production in myocardial cells and inhibited the infiltration of inflammatory cells in the margin area of infarction of the myocardial tissues (P<0.01). The expressions of PGC-1α, SIRT1 and AMPK were increased in the DQT group (all P<0.05). Furthermore, the downstream targets, including MFN1, MFN2 and SOD2 were up-regulated (P<0.05 or P<0.01). Compared with the TMZ group, the expression levels of PGC-1α, MFN1 and SOD2 were increased by DQT treatment (P<0.05 or P<0.01).@*CONCLUSION@#DQT regulated energy metabolism in rats with ischemic heart model through AMPK/SIRT1 -PGC-1α pathway. PGC-1α might serve as a promising target in the treatment of ischemic heart disease.
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OBJECTIVES@#To investigate the effect of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) on liver injury induced by periodontitis in rats.@*METHODS@#Twenty-four male Wistar rats were randomly divided into two groups: control group and periodontitis group, twelve per group. In periodontitis group, the periodontitis models were established for the maxillary first molars in rats by means of "wire ligation+vaccinationwith @*RESULTS@#The probing depth, tooth mobility and sulcus bleeding index in periodontitis group were significantly higher than that in control group. HE staining showed in periodontitis group, hepatic cords ranged disorderly and there were vacuoles in cells and inflammatory cells infiltrated in liver tissues of rats, and there was no obvious abnormality in control group. The qRT-PCR results showed that the mRNA expression levels of @*CONCLUSIONS@#PGC-1α may be involved in the process of periodontitis-induced liver injury in rats.
الموضوعات
Animals , Male , Rats , Liver/injuries , PPAR gamma , Periodontitis/pathology , Rats, Wistarالملخص
Objective: To explore the expression levels of miR-23a-3p and miR-27a-3p in the sera of mice with ulcerative colitis (UC) and their potential action mechanisms. Methods: Twenty C57BL/6 mice were randomly divided into the control group and the model group with 10 mice in each group. The model group mice were induced orally by water with 5% dextran sulfate sodium (DSS) for 7 d. During the induction period, the general condition, fecal morphology and occult blood status of the mice were observed. After 7 d, the whole blood and colon tissues of mice were collected, and the colon lengths and wet weights were measured. The expressions of miR-23a-3p and miR-27a-3p in the sera were detected by qRT-PCR. The expressions of peroxisome proliferator-activated receptor γ, coactivator-1α (PPARGC1A), PH domain leucine-rich repeat protein phosphatase 2 (PHLPP2), B-cell lymphoma-2 (BCL-2), BCL-2 associated X protein (BAX), cytochrome c (CYT-C) and cleaved cysteine-containing aspartate-specific protease (cleaved-caspase-3) were detected by Western blotting. Results: After DSS induction, the model group mice showed mental depression, weight loss, diarrhea, and bloody stool, whose colon lengths were shortened and colon wet weights decreased. The UC model was constructed successfully. In the model group, the expressions of miR-23a-3p and miR-27a-3p in the sera decreased significantly (P<0.05), and the expressions of PPARGC1A, PHLPP2, BAX, CYT-C and cleavedcaspase- 3 in the colon tissues increased significantly (P<0.05), but BCL-2 decreased (P<0.05). Conclusion: The expressions of miR-23a-3p and miR- 27a-3p are low in the sera of UC mice, which may be involved in the occurrence and development of UC by up regulating the expressions of PPARGC1A and PHLPP2 in the colons and triggering mitochondrial pathway to induce apoptosis.
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OBJECTIVE: To investigate the effects of total flavonoids from Psidium guajava leaves (GLTF) on the related factors for estrogen-associated receptor γ(ERRγ)/cyclic adenosine monophosphate responsive element binding protein H(CREBH)pathway in liver of type 2 diabetes mellitus(T2DM)model mice, and to investigate the specific mechanism of its hypoglycemic effect. METHODS: Healthy male ICR mice were collected. T2DM models were established by high-sugar and high-fat diet feeding combined with repeated intraperitoneal injection of low dose streptozotocin. According to the blood glucose value, model mice were randomly divided into model group, metformin group(positive control, 0.17 g/kg),Xiaoke jiangtang capsule group(positive control, 0.75 g/kg),GLTF low-dose and high-dose groups(0.047, 0.094 g/kg), with 12 mice in each group. Another 12 normal mice were included in normal group. Except that normal group and model group were given constant volume of water intragastrically, other groups were given relevant solution 10 mL/kg intragastrically, qd, for consecutive 21 d. After administration, fasting blood glucose and serum insulin levels of mice were measured and insulin sensitivity index (ISI) was calculated. Histopathological changes of liver and pancreas were observed by HE staining. The protein expressions of ERRγ and CREBH in liver tissues were detected by immunoblotting. The mRNA expression of peroxisome proliferator-activated receptor-γ coactivator-1α(PGC1α)and CREB protein co-activator 2(TORC2)in liver tissue of mice were measured by RT-PCR. RESULTS: Compared with normal group, the levels of fasting blood glucose and serum insulin in T2DM mice were significantly increased in model group, while ISI was decreased significantly (P<0.01). The pathological changes of liver tissue were obvious and a large number of vacuoles could be seen. The number and volume of islets in pancreatic tissue decreased, and islet cells showed mild vacuolar lesions. The protein expression of ERRγ and CREBH, mRNA expression of PGC1α and TORC2 in liver tissue were increased significantly (P<0.01). Compared with model group, above blood glucose, insulin indexes and pathological changes were improved significantly in GLTF groups. Protein expression of ERRγ and CREBH, mRNA expression of PGC1α and TORC2 in liver tissue were decreased significantly (P<0.05 or P<0.01). CONCLUSIONS: GLTF showed obvious hypoglycemic effect on T2DM model mice; its mechanism might be related to inhibiting ERRγ/CREBH signaling pathway.
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We studied the protective effect and mechanism of isorhamnetin (ISO) on 1-methyl-4-phenylpyridiniumion (MPP+)-induced SH-SY5Y cells injury. MPP+-induced SH-SY5Y cell injury model was established, and cell viability was measured by MTT and LDH methods. The activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in cells were determined to investigate the level of oxidative stress. DCFH-DA and MitoSOX fluorescence probes were used to detect the levels of intracellular reactive oxygen species (ROS) and mitochondria superoxide, respectively. JC-1 fluorescence probe was used to detect the changes of mitochondrial membrane potential. Western blot and immunofluorescence methods were used to determine the expressions of Sirt1 and PGC-1 proteins, as well as the expression levels of apoptosis-related proteins Bax and Bcl-2. MPP+ at the dose of 500 μmol·L-1 significantly reduced SH-SY5Y cells viability to 52.46% and increased LDH release to 417.63%. ISO at 5 and 15 μmol·L-1 significantly increased the expression of Sirt1 and PGC-1α, inhibited LDH release, reduced intracellular ROS and mitochondria superoxide, inhibited the decline of mitochondrial membrane potential and increased cell viability to 61.61% and 67.55%. In addition, ISO could downregulate the expression of Bax and upregulate the expression of Bcl-2 to reduce cell apoptosis. ISO-mediated inhibition of apoptosis could be reversed by Sirt1 specific inhibitor Sirtinol. Through activating Sirt1/PGC-1α signaling pathway, ISO could reduce oxidative stress injury and inhibit cell apoptosis to protect cells from MPP+ injury.
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Diabetic peripheral neuropathy (DPN) is a progressive neurodegenerative disease of peripheral nervous system with high energy requirement. The adenosine monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor- γ coactivator 1 α (PGC-1 α) axis plays a key role in regulating mitochondrial energy metabolism. Increasing preclinical evidences have shown that inhibition of AMPK/PGC-1 α pathway leading to mitochondrial dysfunction in neurons or Schwann cells contributes to neuron apoptosis, distal axonopathy and nerve demyelination in DPN. Some Chinese medicine formulae or extracts from herbs may have potential neuroprotective effects on DPN via activating AMPK/PGC-1 α pathway and improving mitochondrial function.
الموضوعات
Humans , AMP-Activated Protein Kinases , Metabolism , Diabetic Neuropathies , Drug Therapy , Pathology , Medicine, Chinese Traditional , Mitochondria , Metabolism , Pathology , Neuroprotective Agents , Therapeutic Uses , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha , Metabolism , Signal Transductionالملخص
Objective To investigate the role of epigenetic regulations of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) in the development of diabetic retinopathy and the metabolic memory phenomenon after hyperglycemia was terminated.Methods Diabetic rat model was established by intraperitoneal injection of streptozotocin (STZ).Sixty diabetic rats were randomly divided into 3 groups,poor glycemic control group rats were maintained in poor glycemic control for 4 months;semi glycemic control group rats were maintained in poor glycemic control for 2 months,followed by good glycemic control for 2 additional months;good glycemic control group rats were maintained in good glycemic control for 4 months.Twenty normal rats served as control group.The mRNA expression of PGC-1α and superoxide dismutase 2 (SOD2) of retina were measured by real-time PCR;the expression of PGC-1α and manganese superoxide dismutase (MnSOD) protein were measured by Western blot;the situation of DNA methylation in the promotor region of PPARGC1A was measured by bisulfite sequencing.Results The body-weight in the control group was significantly higher than that in the poor glycemic control group,semi glycemic control group and good glycemic control group (all at P =0.000).The blood glucose value in the poor glycemic control group was significantly higher than that in the control group (P =0.000).The expression levels of PGC-1 α mRNA were significantly lower and the expression levels of SOD2 mRNA were significantly higher in the good glycemic control group,semi glycemic control group and poor glycemic control group than those in the control group (all at P<0.05).The expression levels of PGC-1α and SOD2 mRNA were significantly different between the good glycemic control group and poor glycemic control group (both at P<0.05).Compared with the control group,the expression levels of PGC-1α and MnSOD protein were decreased in the diabetic model groups,with significant differences between them (all at P<0.05).The expression level of PGC-1 α protein was significantly higher in the good glycemic control group than that in the poor glycemic control group (P<0.05).Diabetes increased DNA methylation in the promotor region of PPARGC1A gene of retina.The DNA methylation level was significantly higher in the poor glycemic control group and semi glycemic control group than that in the control group (P =0.008,0.031).No statistical difference was found between the poor glycemic control group and semi glycemic control group (P > 0.05).Conclusions The expressions of PGC-1o mRNA and protein and MnSOD protein in the retina of STZ induced diabetic rats are decreased,the expression of SOD2 mRNA is increased,the expression changes have metabolic memory characteristics.Increased DNA methylation in the promotor region of PPARGC1A when exposed to high glucose may have a role in the regulation of PGC-1 α expression and metabolic memory.
الملخص
AIM:To explore whether down-regulation of peroxisome proliferator-activated receptor γ coactivator (PGC)-1α induces podocyte apoptosis and its mechanism.METHODS:The podocytes were cultured under high glucose (HG) condition and the cell apoptosis was analyzed by flow cytometry.The methods of real-time PCR and Western blot were used to analyze the mRNA and protein expression of related molecules in the control, HG-treated or siRNA-treated podocytes.RESULTS:The expression PGC-1α at mRNA and protein levels was significantly decreased in HG-injured podocytes.Down-regulation of PGC-1α expression in vitro by siRNA resulted in podocyte apoptosis.The nuclear protein expression of nuclear factor of activated T-cells (NFAT) was significantly increased in HG injured podocytes, indicating the NFAT activation.Down-regulation of PGC-1α expression also decreased the nuclear protein expression of NFAT.Moreover, silencing of NFAT expression by siRNA significantly abolished PGC-1α deficiency-induced podocyte apoptosis.CONCLUSION: Down-regulation of PGC-1α induces podocyte apoptosis.NFAT mediates PGC-1α deficiency-induced podocyte apoptosis.
الملخص
AIM:To evaluate the regulatory effect of microRNA-132 ( miR - 132 ) in human umbilical vein endothelial cell ( HUVEC) . ●METHODS: ln vitro cultured human umbilical vein endothelia cells in hypoxic environment for 6h, then maintained under normal oxygen condition for 3h, 6h, 12h, 24h. miR-132 and peroxisome-proliferator-activated receptor-γ coactivator-1α ( PGC-1α) expression was detected by quantitative Real - time polymerase chain reaction and Western blot analysis. Human umbilical vein endothelial cells transfected miR-132 mimic and miR-132 inhibitor( anti-miR-132 ) were measured by quantitative Real-time polymerase chain reaction and Western blot. ●RESULTS: miR - 132 and PGC - 1α expression was significantly ( P ●CONCLUSION:miR-132 level is highly expressed in the HUVEC under hypoxia and may be an effect of regulation for PGC-1α.
الملخص
Endurance exercise training such as marathon can increase the ability of exercise performance. Muscle glycogen is associated with an exercise performance, because glycogen depletion is primary causes of muscle fatigue. This review summarizes the glycogen saving effect according to duration of endurance exercise training. Long-term endurance exercise-induced mitochondrial biogenesis contributes to glycogen saving effect that is reduced glycogen breakdown and lactate accumulation. Glycogen sparing is due to a smaller decrease in adenosine triphosphate and phosphocreatine and a smaller increase in inorganic phosphate in the working muscles. It takes required endurance exercise training for about 4 weeks or more. Single bout or short-term endurance exercise is not sufficient to bring an increase in functional mitochondria. But peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) increases rapidly after single bout of endurance exercise. PGC-1α downregulates glycogenolytic and glycolytic enzymes to reduce muscle glycogen breakdown and lactic acid accumulation after short-term endurance exercise.
الموضوعات
Adenosine Triphosphate , Glycogen , Glycogenolysis , Lactic Acid , Mitochondria , Muscle Fatigue , Muscle, Skeletal , Muscles , Organelle Biogenesis , Peroxisomes , Phosphocreatineالملخص
Recent studies indicate that exercise with a low muscle glycogen state enhances exercise-induced metabolic adaptation. However, it is unclear whether metabolic adaptation is involved with muscle glycogen depletion level. In this study, we investigated the effects of prior muscle glycogen depletion level on metabolic response during acute continuous exercise. Seven men completed two experimental trials consisting of two exercise sessions per day. During the first session, participants performed either intermittent exercise (IE) at VO<sub>2</sub>max (the IE-CE trial) or continuous exercise (CE) at lactate threshold (the CE-CE trial). During the second session, participants performed 60 minutes of CE at lactate threshold. During this second session, fatty acid oxidation (FAO) was calculated. To determine muscle glycogen content and PGC-1α and PDK-4 mRNA abundance, muscle biopsies were taken at rest after the first session and 2 hours after the second session. After the first session, muscle glycogen content was significantly lower in the IE-CE trial (38.1±5.0 mmol/kg w.w.) than in the CE-CE trial (56.7±10.2 mmol/kg w.w.), <i>P</i><0.05. FAO was higher in the IE-CE trial than the CE-CE trial at baseline and 15 minutes after the second session (both <i>P</i><0.05). PGC-1α mRNA abundance increased after exercise (IE-CE, 5.9±2.5; CE-CE, 2.6±1.3-fold; <i>P</i><0.1). PDK-4 mRNA abundance increased significantly after exercise (IE-CE, 22.2±8.8; CE-CE, 31.5±10.6-fold; <i>P</i><0.05). PGC-1α and PDK-4 mRNA were not significantly different between the trials. In conclusion, continuous exercise with a slightly muscle glycogen-depleted state induced similar level of PGC-1α and PDK-4 mRNA expression, but attenuated FAO, compared to exercise with a moderate muscle glycogen-depleted state.