PGC-1α mRNA Levels Research Articles

MiR-183 and miR-96 orchestrate both glucose and fat utilization in skeletal muscle.

Our knowledge of the coordination of fuel usage in skeletal muscle is incomplete. Whether and how microRNAs are involved in the substrate selection for oxidation is largely unknown. Here we show that mice lacking miR-183 and miR-96 have enhanced muscle oxidative phenotype and altered glucose/lipid homeostasis. Moreover, loss of miR-183 and miR-96 results in a shift in substrate utilization toward fat relative to carbohydrates in mice. Mechanistically, loss of miR-183 and miR-96 suppresses glucose utilization in skeletal muscle by increasing PDHA1 phosphorylation via targeting FoxO1 and PDK4. On the other hand, loss of miR-183 and miR-96 promotes fat usage in skeletal muscle by enhancing intramuscular lipolysis via targeting FoxO1 and ATGL. Thus, our study establishes miR-183 and miR-96 as master coordinators of fuel selection and metabolic homeostasis owing to their capability of modulating both glucose utilization and fat catabolism. Lastly, weshow that loss of miR-183 and miR-96 can alleviate obesity andimprove glucose metabolism in high-fat diet-induced mice, suggesting that miR-183 and miR-96 may serve as therapeutic targets for metabolic diseases.

FNDC5 expression closely correlates with muscle fiber types in porcine longissimus dorsi muscle and regulates myosin heavy chains (MyHCs) mRNA expression in C2C12 cells.

BackgroundIrisin (a glycosylated protein) is cleaved from fibronectin type III domain-containing protein 5 (FNDC5), which is expressed mainly in animal muscle tissues and has multiple metabolic regulatory activities. However, their roles in controlling myofiber types in skeletal muscle remain unclear.MethodologyTwo different commercial hybridized pigs, LJH (a crossed pig containing Chinese native pig genotypes) and DLY (Duroc × Landrace × Yorkshire) were selected to analyze FNDC5 mRNA expression and the mRNA composition of four adult myosin heavy chain (MyHC) isoforms (IIIaIIxIIb) in the longissimus dorsi (LD) muscle. C2C12 myoblasts were cultured to investigate the effects of FNDC5 on the four MyHCs mRNA expressive levels, using small interfering RNA for depletion and a eukaryotic expression vector carrying FNDC5 for overexpression. ZLN005 (a small molecule activator of FNDC5’s upstream control gene PGC1α) or recombinant human irisin protein were also used.ResultsIn LD muscle, LJH pigs had the higher FNDC5 mRNA level, and MyHC I or IIa proportion than DLY pigs (P < 0.05). For C2C12 cells in vitro, small interfering RNA (si-592) silencing of FNDC5 expression markedly reduced MyHC IIa mRNA levels (P < 0.05), while FNDC5 overexpression significantly increased MyHC IIa mRNA levels (P < 0.05). Exogenous irisin increased the mRNA levels of PGC1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha), FNDC5, MyHCI, MyHCIIa, NRF1 (nuclear respiratory factor 1), VEGF (vascular endothelial growth factor), and TFAM (mitochondrial transcription factor A,) (P < 0.05), and the enzyme activities of SDH (succinate dehydrogenase), CK (creatine kinase), and MDH (malate dehydrogenase) in C2C12 myotubes (P < 0.05). These results showed that FNDC5 mRNA expression had a significant association with the characteristics of myofiber types in porcine muscle, and participated in regulating MyHCs mRNA expression of C2C12 myogenic differentiation cells in vitro. FNDC5 could be an important factor to control muscle fiber types, which provides a new direction to investigate pork quality via muscle fiber characteristics.

The effects of different training modalities on monocarboxylate transporters MCT1 and MCT4, hypoxia inducible factor-1α (HIF-1α), and PGC-1α gene expression in rat skeletal muscles.

The research literature suggests that different training modalities cause various patterns in training-induced genes expression. This study aimed to investigate the effects of moderate intensity continuous training (MICT) and isocaloric high intensity interval training (HIIT) on gene expression of monocarboxylate transporter 1 (MCT1) and 4 (MCT4), Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), and hypoxia inducible factor-1α (HIF-1α) in soleus and extensor digitorum longus (EDL) skeletal muscles of rats. Thirty male Sprague-Dawley rats were divided into 3 groups of control, MICT, and HIIT. Training protocols were performed according to the principle of overload for 8weeks and 5 sessions per week. Then, the soleus and EDL muscles were extracted and the expression levels were analyzed using the real time PCR method. In the MICT group, only the EDL HIF-1α mRNA level was significantly higher than that of the control group (p < 0.05). In the HIIT group, however, mRNA levels of MCT4, PGC-1α, and HIF-1α in both muscles were significantly higher than those of the control group (p < 0.05). The comparison between the two training methods demonstrated that the gene expression levels of soleus and EDL MCT4, soleus PGC-1α, and soleus HIF-1α were significantly higher in the HIIT group compared to the MICT group (p < 0.05). There were also significant positive correlations between all mRNA levels of HIF-1α and corresponding mRNA levels of MCT4 (p < 0.05). HIIT caused greater positive responses in the gene expression of MCT4, PGC-1α, and HIF-1α compared to MICT.

The neuroprotective role of SIRT1/PGC-1α signaling in limb postconditioning in cerebral ischemia/reperfusion injury

Limb ischemic postconditioning (LPostC) is an innovative treatment for ischemia/reperfusion injury (IRI). However, its mechanisms have not yet been elucidated. Herein, we assessed the importance of SIRT1/PGC-1α signaling in LPostC neuroprotection following cerebral I/R injury in rats. In this study, we used 40 male SD rats that were separated into sham, I/R, LPostC, and LPostC + EX-527 (SIRT1 inhibitor) groups (each with 10 rats), with a middle cerebral artery occlusion (MCAO) model used to induce IRI. LPostC was induced via three cycles of bilateral femoral artery occlusion and non-occlusion. At 24 h, we examined SIRT1 and PGC-1α protein levels by western blotting in ischemic areas. The mRNA levels of SIRT1, PGC-1α, NRF-1 and CytoC1 in the ischemic area were assessed by qRT-PCR. We also quantified neurological deficit scores and evaluated cerebral infarct volume by TTC staining. TUNEL staining was used to evaluate the apoptotic rates in neurons. In addition, antioxidant SOD activity and MDA levels were measured by the Microplate Reader. Our findings indicated that LPostC increased the protein and mRNA levels of SIRT1 and PGC-1α in cerebral ischemic tissue, then up-regulated the downstream protein NRF-1, down-regulated CytoC1, and improved mitochondrial function, thereby reducing brain damage. LPostC relieved cerebral IRI via reducing the size of the cerebral infarct, neuronal apoptosis, and neurological deficits. Meanwhile LPostC increased SOD activity and reduced MDA content in brain tissue. Treatment with EX-527 reversed the protection of LPostC after IRI (all P < 0.05). This suggests that LPosC may protect against cerebral IRI at least in part via up-regulating the SIRT1/PGC-1α signaling pathway, thereby increasing the individual’s ability to resist oxidative stress.

Ginsenoside rg3 reduces body weight by regulating fat content and browning in obese mice

To determine the effects of ginsenoside rg3 on the body weight of C57BL/6J obese mice and to investigate its underlying weight loss mechanisms with a focus on white fat browning-related factors. Eight-week-old C57BL/6J male mice were fed a high-fat diet for 12 successive weeks to construct the obese model. C57BL/6J male mice were fed a standard chow diet to construct normal control group. After 8 weeks of intervention with ginsenoside rg3, the food intake, body weight, body fat mass, blood sugar, and lipid profiles of the mice in each group were detected. Hematoxylin and eosin (HE) staining was used to observe the histological morphology of the adipose tissues. Real-time polymerase chain reaction (RT-PCR) and Western blotting (WB) were applied to detect the gene and protein expression levels of peroxisome proliferators-activated receptor gama (PPARγ), Peroxisome proliferator-activated receptor-gamma coactivator -1alpha (PGC-1α), PR domain containing 16 (PRDM16), and uncoupling protein 1 (UCP-1). Compared to normal control group mice, the body weight, food intake, body fat composition, and blood lipid levels of model group mice increased significantly. After 8 weeks of intervention with ginsenoside rg3, body weight, body fat composition, food intake, and blood lipid profiles decreased. HE staining showed that ginsenoside rg3 can improve white adipocyte hypertrophy to a certain extent. RT-PCR and WB demonstrated that ginsenoside rg3 can increase the mRNA and protein expression levels of PPARγ, PGC-1α, PRDM16, and UCP-1 in the adipose tissues of obese mice. The weight reduction effect of ginsenoside rg3 may be related to the promotion of white fat browning.

Effect of chronic AICAR treatment on muscle fiber composition and enzyme activity in skeletal muscle of rats

ABSTRACT Muscle fiber is the basic unit of skeletal muscle. Muscle fiber types play a crucial role in improving meat quality. In the current study, Wistar rats were chronic injected with 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) for four weeks in order to define the 5′-AMP-activated protein kinase (AMPK) protein activity on muscle fiber composition, enzyme activity and the mRNA expression of muscle fiber type-related genes in gastrocnemius (GS) muscle. Food intake and body weight did not show a significant difference after AICAR treatment (P > .05). The AICAR treatment caused a significantly increased number and area proportion of type I muscle fiber and expression level MyHC I mRNA (P < .05), succinic dehydrogenase (SDH) and malate dehydrogenase (MDH) activities (P < .05), but decrease in the number proportion of type IIB muscle fiber and MyHC IIb and MyHC IIx mRNA level (P < .05). The Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) mRNA level (P < .05) was increased and glucose transporter 4 (GLUT-4) mRNA level tended to be higher (P = .052) in the AICAR group. These results demonstrated that chronic AICRA treatment induces oxidative muscle fiber switching, enhances oxidative enzyme activity and GLUT4 mRNA level, mediated by PGC-1α.

Disturbance of di-(2-ethylhexyl) phthalate in hepatic lipid metabolism in rats fed with high fat diet

Di-(2-ethylhexyl) phthalate (DEHP), which is widely used as an industrial plasticizer, may cause liver damage. Concomitantly, bad dietary habits can exacerbate the liver burden. In this study, high-fat diet (HFD)-fed rats were treated with DEHP (10, 100, or 300 mg/kg bw) for 5 weeks, and a biochemical method was adopted to detect serum lipid contents. Key metabolic genes and pathological changes were assessed by different methods (RT-PCR, Western Bloting, ELISA and HE staining). The rats which were exposed to DEHP at a dose of 10 mg/kg bw exhibited dyslipidemia and increased transcription of SREBP-1 and its target FAS, thereby prompting de novo lipogenesis, but they did not become obese. Instead, DEHP at a dose of 300 mg/kg bw elevated the levels of AMPK phosphorylation and the mRNA levels of PPAR-α, PGC-1α, CPT-1 and lipin-1 in the liver, which led to fatty acid oxidation. Additionally, DEHP at the highest dose increased the TNF-α mRNA expression in the liver. Based on these findings, we conclude that excess fatty acid oxidation might increase the inflammatory response. No toxic effects on hepatic function were observed. These findings suggest that different doses of DEHP have the potential to disturb hepatic metabolic imbalance in HFD-fed rats.

Irisin/FNDC5: A participant in camel metabolism.

The quantification, localization, production, function, and regulation of irisin/FNDC5 in camel species have not been previously studied. The objective of this study was to detect the irisin content in Arabian camel blood and tissues and study the gene expression of FNDC5 and PGC-1α in camel skeletal muscles and white adipose tissue depots under basal conditions. To monitor if exercise influences blood and tissue irisin protein levels as well as FNDC5 and PGC-1α gene expression levels, we analyzed irisin concentrations in the serum, skeletal muscles (soleus and gastrocnemius), and white adipose tissues (hump, subcutaneous, visceral, epididymal, and perirenal) in both control (n = 6) and exercised group (n = 6) using ELISA and determined the cellular localization of irisin/FNDC5 and the mRNA levels of FNDC5 and PGC-1α in skeletal muscles and adipose tissues via immunohistochemistry and real-time PCR, respectively. The possible regulatory roles of exercise on some hormones and metabolites as well as the detection of links between serum irisin and other circulating hormones (insulin, leptin, and cortisol) and metabolites (glucose, free fatty acids, triglycerides, and ATP) were explored for the first time in camels. Our results indicated that exercise induces tissue-specific regulation of the camel irisin, FNDC5, and PGC-1α levels, which subsequently regulates the circulating irisin level. Significant associations were detected between the levels of irisin/FNDC5/PGC-1α in camels and the metabolic and hormonal responses to exercise. Our study suggested that irisin regulates, or is regulated by, glucose, FFA, insulin, leptin, and cortisol in camels. The novel results of the present study will serve as baseline data for camels.

Role of PDK4 in insulin signaling pathway in periadrenal adipose tissue of pheochromocytoma patients.

Studies have shown that pheochromocytoma (PHEO) is associated with glucose intolerance and decreased insulin sensitivity. In adipocytes, pyruvate dehydrogenase kinase 4 (PDK4) is involved in glucose uptake. However, very little is known about the role of PDK4 in the insulin signaling pathway in the adipose tissue of PHEO patients. We analyzed the expression of adipokines, oxidative stress-related genes, PDK4, phosphorylated AMPK (pAMPK) and phosphorylated IRS1 (pIRS1) in the periadrenal adipose tissue (peri-A) of patients with PHEO and non-functioning adrenal adenoma (NFA). We also investigated the effects of epinephrine on PDK4, pAMPK and pIRS1 in human stromal vascular fraction (SVF) cells, mouse 3T3-L1 preadipocytes and brown preadipocytes. PHEO patients had higher mRNA levels of PGC1α, C/EBPα, C/EBPβ, COXII and AP2 and lower mRNA levels of PPARγ in their peri-A than NFA patients. Decreased pAMPK and increased PDK4 and pIRS1 were observed in the peri-A of PHEO patients. PHEO patients also had significantly higher NOX4 protein expression and lower Nrf2 and HO-1 protein expression in their peri-A than NFA patients. In vitro, epinephrine treatment upregulated PDK4 expression, inhibited AMPK phosphorylation and enhanced IRS1 phosphorylation. The knockdown of PDK4 by siRNA upregulated pAMPK and downregulated pIRS1. In conclusion, PDK4 may play an essential role in hypercatecholamine-induced insulin resistance in the periadrenal adipose tissues of PHEO patients.

Long-term nitrate administration increases expression of browning genes in epididymal adipose tissue of male type 2 diabetic rats

Expression of browning genes are lower in both humans and animals with type 2 diabetes (T2D). This study aims at determining effects of long-term nitrate administration on protein and mRNA levels of uncoupling protein 1 (UCP1), peroxisome proliferator activated receptor gamma (PPAR-γ), and PPAR-γ coactivator 1 alpha (PGC1-α) in epididymal adipose tissue (eAT) of rats with T2D. Male Wistar rats were divided into 4 groups (n = 6/group): Control, diabetes, control + nitrate (CN), and diabetes + nitrate (DN). T2D was induced using high fat diet combined with a low-dose of streptozotocin (30 mg/kg body weight). Sodium nitrate was administrated at a dose of 100 mg/L for 6 months in nitrate-treated rats. Fasting serum glucose and insulin concentrations were measured at months 0 (i.e. at start of the protocol), 3, and 6. At month 6, protein and mRNA levels of UCP1, PPAR-γ, and PGC1-α were measured in eAT samples. In addition, tissue concentration of cyclic guanosine monophosphate (cGMP) was measured and histological analyses were done at month 6. In rats with T2D, 6-month administration of nitrate decreased serum glucose and insulin concentrations by 13% and 23%, respectively and increased cGMP level by 85%. Rats with T2D had lower mRNA and protein levels of PPAR-γ (62%, P < 0.0001 and 18%, P = 0.0472), PGC1-α (49%, P = 0.0019 and 21%, P = 0.0482), and UCP1 (35%, P = 0.0613 and 30%, P = 0.0031) in eAT; 6-month nitrate administration restored these decreased levels to near control values. In addition, nitrate increased adipocyte density by 193% and decreased adipocyte area by 53% in rats with T2D. In conclusion, long-term low-dose nitrate administration increased mRNA and protein expressions of browning genes in white adipose tissue of male rats with T2D; these findings partly explain favorable metabolic effects of nitrate administration in diabetes.

Transcriptional Activation Of Hypoxia Sensitive Genes Following Repeated Sprint Exercise In Hypoxia

Repeated sprint training in hypoxia (RSTH) utilizes short supramaximal efforts followed by incomplete rest intervals. RSTH has been shown to improve repeated sprint performance compared to repeated sprint training in normoxia. Because of the relatively short exposure to hypoxia compared to live high, train low approaches, the benefits of RSTH have been attributed to local muscular adaptations rather than hypoxia-induced erythropoiesis. Repeated activation of the hypoxia sensitive transcription factors HIF-1α and PGC-1α, and regulation of their gene targets related to angiogenesis (VEGF), mitophagy (BNIP3, PINK1), and glucose metabolism (PDK-M, GLUT4) may underlie these muscular adaptations. PURPOSE: To investigate the transcriptional activation of HIF-1α, PGC-1α and several HIF-1α-target genes following repeated sprint exercise in normoxia and hypoxia. METHODS: Eight recreationally active males (n=8) and one female (n=1) performed 20, 10s all-out sprints in normoxia (1600m) and hypobaric hypoxia (4600m) on a cycle ergometer on two days separated by 2 weeks. Skeletal muscle samples from the vastus lateralis were analyzed for mRNA levels of HIF-1α, PGC-1α, BNIP3, PINK1, VEGF, PDK-M, and GLUT4 pre, post and 3h post exercise in hypoxia and normoxia. Comparisons between condition and time were made using two-way repeated measures ANOVAs. RESULTS: There was a significant increase in mRNA levels for HIF-1α (fold change: 2.6±1.8) and VEGF (fold change: 3.0±1.6) 3h post-exercise in hypoxia (p<.05) but not normoxia. PGC-1α, was higher 3h post-exercise in both hypoxia (fold change: 9.2±4.6) and normoxia (fold change: 6.2±3.8; p<.05). No significant effect of time or group was observed for BNIP3, PINK1, PDK-M, or GLUT4. CONCLUSIONS: Acute sprint exercise in both hypoxia and normoxia induces an increase in the transcription of PGC-1α. However, hypoxia sensitive genes HIF-1α and VEGF were only greater following sprint exercise in hypoxia. Collectively, these findings suggest that sprint exercise stimulates mitochondrial biogenesis, but an additional hypoxic stress is required to induce changes in hypoxia sensitive genes. The downstream effect of these transcriptional activations may increase angiogenesis and mitochondrial signaling in response to RSTH, which may in part explain the benefits of RSTH.

β-Caryophyllene Reduces the Inflammatory Phenotype of Periodontal Cells by Targeting CB2 Receptors.

Human gingival fibroblasts (GF) and human oral mucosa epithelial cells (EC) with an inflammatory phenotype represent a valuable experimental paradigm to explore the curative activity of agents to be used in oral mucositis. The role of cannabinoid receptor 2 (CB2) has not yet been investigated in oral mucositis. The aim of this study was to evaluate the therapeutic potential of β-Caryophyllene (BCP), a CB2 agonist, in an in vitro model of oral mucositis. GF and EC were stimulated with LPS (2 µg/mL) alone or in combination with BCP; a group of LPS challenged GF and EC were treated with BCP and AM630, a CB2 antagonist. LPS increased the inflammatory cytokines TNF-α, IL-1β, IL-6 and IL-17A whereas it decreased the anti-inflammatory cytokine IL-13. The upstream signals were identified in an augmented expression of NF-κB and STAT-3 and in reduced mRNA levels of PPARγ and PGC-1α. BCP blunted the LPS-induced inflammatory phenotype and this effect was reverted by the CB2 antagonist AM630. These results suggest that CB2 receptors are an interesting target to develop innovative strategies for oral mucositis and point out that BCP exerts a marked curative effect in a preclinical model of oral mucositis which deserves to be confirmed in a clinical setting.

1957-P: Intermittent Ketogenic Diet Ameliorates Diet-Induced Obesity and Fatty Liver with Improved FGF21 Signaling

Recently, ketogenic diet has been found to be effective on improving obesity. Fibroblast growth factor 21 (FGF-21) is an endocrine factor mainly synthesized in the liver and shown to impact the metabolism of multiple tissues. Here, we investigated the effect of intermittent ketogenic diet on obesity and the sensitivity of FGF-21. Eight-week-old C57BL/6 mice were subjected to a chow diet (CD group), a high fat diet (HFD group), an intermittent chow diet (iCD group) or an intermittent ketogenic diet (iKD group) for 16 weeks. The intermittent diet intervention began with an HFD and was alternated with a chow diet or a ketogenic diet biweekly. Although the average energy intake of iKD group was highest in the four groups, the body weight, fasting blood glucose, the body fat mass and the weight of liver, epididymal adipose tissues (eWAT), subcutaneous adipose tissue (sWAT) and brown adipose tissue (BAT) of iKD group were ameliorated remarkably when compared to HFD group. The insulin sensitivity of iKD group was greatly improved as well. Both the histological results and the quantification of liver triglyceride showed that hepatic steatosis was significantly alleviated in iKD group. Western blotting showed that lipid metabolism in liver was greatly improved by iKD. What’s more, the cold exposure test showed that the iKD group had the best cold tolerance in the four groups. The mRNA expression of FGF-21 was greatly upregulated and hepatic inflammation was ameliorated in livers of iKD group. HE staining showed that the adipocytes in eWAT and sWAT were smaller in iKD group. The whitening of BAT was also improved in iKD group. Both mRNA and protein levels of UCP1 and PGC1α were remarkably upregulated by iKD in eWAT, sWAT and BAT. The mRNA levels of FGFR1 and KLB, which are related to FGF-21 sensitivity, were observed to be improved in eWAT and sWAT. Our data demonstrated that iKD ameliorates diet-induced obesity and fatty liver, and improved insulin sensitivity and cold tolerance with improved FGF-21 signaling. Disclosure W. Guo: None. W. Wang: None. W. Li: None.

The effect of TGFβ1 on thermogenic markers is dependent on the degree of adipocyte differentiation.

Transforming growth factor β (TGFβ) a multifunctional cytokine is known to regulate cell proliferation, differentiation, migration and survival. Although there is variable expression of modulators of TGFβ action during differentiation, a differential effect on fat cell metabolism at the different stages of adipocyte differentiation was unclear. In the present study, 3T3L1 cells were used as an in vitro model to study the effect of TGFβ on adipogenic and thermogenic markers at various stages of preadipocyte to mature adipocyte differentiation. As in our earlier studies on the effect of TGFβ on CEBP’s, we used a standard differentiation mix, and one with the addition of rosiglitazone. RhTGFβ1 was added to undifferentiated adipocytes (preadipocytes) and to adipocytes at day 0 (commitment stage) as well as day 10 (terminal differentiation). Cellular responses in terms of Pref1, PPARγ, TLE3, PGC1α, PRDM16, UCP1 and UCP2 mRNA levels and selected protein products, were determined. Increases in PPARγ, PRDM16, UCP1 and UCP2 mRNA and decreases in Pref1 are good indicators of successful differentiation. The early addition of rhTGFβ1 during commitment stage decreased PPARγ, PRDM16, TLE3, UCP1 and UCP2 mRNA and decreased PRDM16 protein consistent with our earlier report on the inhibition of CEBP’s by TGFβ and CCN2. The addition of rhTGFβ1 to mature adipocyte at day 10 increased UCP1 mRNA and increased PRDM16 and UCP1 proteins. In the present study, our results suggest that TGFβ1 added late enhances the thermogenic potential of mature cells and causes 3T3L1 cells to differentiate to resemble brown or beige rather than white adipose tissue.

Sirt6 opposes glycochenodeoxycholate-induced apoptosis of biliary epithelial cells through the AMPK/PGC-1\u03b1 pathway

BackgroundInduction of biliary epithelial cell apoptosis by toxic bile acids is involved in the development of cholestatic disease, but the underlying molecular mechanism is not clear. The purpose of this study was to investigate the molecular mechanisms involved in Sirt6 protection against the apoptosis of human intrahepatic biliary epithelial cells (HiBEC) induced by the bile acid glycochenodeoxycholate (GCDC).ResultsSirt6 was either overexpressed or knocked down in HiBEC, with or without GCDC pretreatment. The CCK-8 assay was used to assess cell viability and, Hoechst 33258 staining was used to determine apoptotic rate. Mitochondrial DNA (mtDNA) copy number, malondialdehyde (MDA) and reactive oxygen species (ROS) production were detected to evaluate the severity of the mitochondrial dysfunction and oxidative stress. The mRNA and protein levels of PGC-1α, Nrf1, and Nrf2 were analyzed using RT-qPCR and western blot assay. The results showed that Sirt6 opposed GCDC-induced apoptosis in HiBEC via up-regulating PGC-1α expression and stabilizing mtDNA. We used agonists and inhibitors of AMPK to demonstrate that Sirt6 increased PGC-1α expression through the AMPK pathway whereas GCDC had the opposite effect. Finally, western blot, luciferase assay, and co-immunoprecipitation were used to describe a direct interaction and acetylation modification of PGC-1α by Sirt6.ConclusionOur data illuminated that Sirt6 ameliorated GCDC-induced HiBEC apoptosis by upregulating PGC-1α expression through the AMPK pathway and its deacetylation effect.

Exercise Induces Different Molecular Responses in Trained and Untrained Human Muscle.

Human skeletal muscle is thought to have heightened sensitivity to exercise stimulus when it has been previously trained (i.e., it possesses "muscle memory"). We investigated whether basal and acute resistance exercise-induced gene expression and cell signaling events are influenced by previous strength training history. Accordingly, 19 training naïve women and men completed 10 wk of unilateral leg strength training, followed by 20 wk of detraining. Subsequently, an acute resistance exercise session was performed for both legs, with vastus lateralis biopsies taken at rest and 1 h after exercise in both legs (memory and control). The phosphorylation of AMPK and eEF2 was higher in the memory leg than that in the control leg at both time points. The postexercise phosphorylation of 4E-BP1 was higher in the memory leg than that in the control leg. The memory leg had lower basal mRNA levels of total PGC1α and, unlike the control leg, exhibited increases in PGC1α-ex1a transcripts after exercise. In the genes related to myogenesis (SETD3, MYOD1, and MYOG), mRNA levels differed between the memory and the untrained leg; these effects were evident primarily in the male subjects. Expression of the novel gene SPRYD7 was lower in the memory leg at rest and decreased after exercise only in the control leg, but SPRYD7 protein levels were higher in the memory leg. In conclusion, several key regulatory genes and proteins involved in muscular adaptations to resistance exercise are influenced by previous training history. Although the relevance and mechanistic explanation for these findings need further investigation, they support the view of a molecular muscle memory in response to training.

Anti-obesity effects of individual or combination treatment with Spirulina platensis and green coffee bean aqueous extracts in high-fat diet-induced obese rats

Background: Obesity is associated with serious health risks, including premature mortality. This study investigated the anti-obesity effects of individual or combination treatment with Spirulina platensis and green coffee bean aqueous extracts in high-fat diet-induced (HFD) obese rats.Methods: Rats were fed on HFD to induce obesity. Corn oil in the HFD accounted for 50.98% of the calories. Fifty rats were divided into five groups (10 rats/group): control, HFD, HFD-Spirulina, HFD-coffee, HFD-Spirulina and coffee cotreatment groups. The serum levels of lipid, leptin, and insulin, as well as the hepatic mRNA levels of fatty acid synthase (FAS), peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), and peroxisome proliferator-activated alpha receptor (PPARα) were estimated.Results: The Spirulina and/or green coffee bean aqueous extracts decreased the final bodyweight and liver weight, and the serum levels of alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase. The extracts decreased the serum levels of total cholesterol, triacylglycerol, low-density lipoprotein-cholesterol, leptin, and glucose, and enhanced the serum insulin level. Furthermore, the extracts enhanced the PGC-1α and PPARα mRNA levels and decreased the FAS mRNA levels.Conclusion: The individual or combination treatment with Spirulina platensis and green coffee bean extracts decreased obesity-induced hyperlipidemia and they can be potentially used to treat obesity. Abbreviations: ACC: Acetyl Co-A carboxylase; AF: Activity factor; ALP: Alkaline phosphatase; ALT: Alanine amino transferase; AMP: Adenosine monophosphate; AMPK: AMP activated protein kinase; AST: Aspartate amino transferase; BMI: Body mass index; cAMP: Cyclic adenosine monophosphate; CBE: Coffee bean extract; CVD: Cardiovascular disorder; DRD4: Dopamine receptor D4; FAS: Fatty acid synthase; FFA: Free fatty acid; FTO: Fat mass and obesity gene; GOD: Glucose oxidase; G-6-P: Glucose-6-phosphatase; HDL-C: High-density lipoprotein-cholesterol; HFD: High-fat diet; HMGRCR: 3-hydroxy-3-methylglutaryl CoA reductase; LDL-C: Low-density lipoprotein-cholesterol; LXR α: Liver X receptor α; MC4R: Melanocortin 4 receptor gene’; NO: Nitric oxide; PGC-1α: Peroxisome proliferator-activated receptor gamma coactivator-1 alpha; PPARα: Peroxisome proliferator-activated alpha; PPARγ: Peroxisome proliferator-activated receptor γ; REE: Resting energy expenditure; ROS: Reactive oxygen species; TC: Total cholesterol; T2DM: Type 2 diabetes; TG: Triacyl glycerol; TP: Total protein; VLDL: Very low-density lipoprotein; WLS: Weight loss surgery

PSXIII-3 Maternal eicosapentaenoic acid feeding decreases placental and fetal lipid deposition and improves antioxidant capacity through a Sirtuin-1 independent

Abstract This research aimed to evaluate whether maternal dietary n-3 polyunsaturated fatty acids (PUFA) supplementation could decrease placental lipid deposition and improve placental antioxidant capacity through a SIRT1-dependent way. In the present study, male and female SIRT1+/- mice were mated overnight, then primiparous SIRT1+/- mice were fed a 60% kcal high-fat-diet (HFD) or equienergy EPA diet (4.4% EPA-ethyl ester) (n = 22/each group). At pregnant 18.5 d, retro-orbital blood samples were obtained then sacrificed by cervical dislocation. Placentas and its corresponding fetuses were collected by caesarean section. We found that the EPA diet significantly changed maternal plasma, placenta and fetus fatty acid composition, and decreased placental and fetal lipid content. Meanwhile, EPA treatment significantly increased placental and fetal antioxidant capacity, however, lipid peroxidation products malondialdehyde was also increased. Moreover, EPA treatment significantly activated placental UCP1 and PGC1α expression and alleviated mitochondrial swelling induced by HFD. SIRT1 knockout had no significant effect on placental lipid content, but notably decreased fetal triglyceride (TG) and non-esterified fatty acid (NEFA) content. Meanwhile, SIRT1 knockout significantly decreased the ratio of n-3 PUFA in placenta. SIRT1 knockout also significantly decreased PGC1α mRNA and protein level and increased mitochondrial swelling. Both EPA treatment and SIRT1 deficiency had no effect on BODIPY-FL-C16 (a fluorescent labeled palmitic acid) uptake in placenta and fetus. No significant effect was observed between diet and genotype. In conclusion, our study demonstrated that maternal EPA feeding decreased placental and fetal lipid deposition and improved antioxidant capacity through a Sirtuin-1 independent mechanism.

GBA mutation promotes early mitochondrial dysfunction in 3D neurosphere models.

Glucocerebrosidase (GBA) mutations are the most important genetic risk factor for the development of Parkinson disease (PD). GBA encodes the lysosomal enzyme glucocerebrosidase (GCase). Loss-of-GCase activity in cellular models has implicated lysosomal and mitochondrial dysfunction in PD disease pathogenesis, although the exact mechanisms remain unclear. We hypothesize that GBA mutations impair mitochondria quality control in a neurosphere model.We have characterized mitochondrial content, mitochondrial function and macroautophagy flux in 3D-neurosphere-model derived from neural crest stem cells containing heterozygous and homozygous N370SGBA mutations, under carbonyl cyanide-m-chlorophenyl-hydrazine (CCCP)- induced mitophagy.Our findings on mitochondrial markers and ATP levels indicate that mitochondrial accumulation occurs in mutant N370SGBA neurospheres under basal conditions, and clearance of depolarised mitochondria is impaired following CCCP-treatment. A significant increase in TFEB-mRNA levels, the master regulator of lysosomal and autophagy genes, may explain an unchanged macroautophagy flux in N370SGBA neurospheres. PGC1α-mRNA levels were also significantly increased following CCCP-treatment in heterozygote, but not homozygote neurospheres, and might contribute to the increased mitochondrial content seen in cells with this genotype, probably as a compensatory mechanism that is absent in homozygous lines.Mitochondrial impairment occurs early in the development of GCase-deficient neurons. Furthermore, impaired turnover of depolarised mitochondria is associated with early mitochondrial dysfunction.In summary, the presence of GBA mutation may be associated with higher levels of mitochondrial content in homozygous lines and lower clearance of damaged mitochondria in our neurosphere model.

The Neuroprotective Effect of the Adiponectin Receptor Agonist AdipoRon on Glutamate-Induced Cell Death in Rat Primary Retinal Ganglion Cells.

Purpose: To determine whether the adiponectin receptor (AdipoR) agonist AdipoRon inhibits glutamate-induced neuronal cell death and to investigate the neuroprotective mechanism of AdipoRon in rat primary retinal ganglion cells (RGCs). Methods: The expression pattern of AdipoR1 and AdipoR2 in rat retina and primary RGCs was examined by immunostaining. The neuroprotective effect of AdipoRon on glutamate-induced cell death was evaluated in rat primary RGCs. Cellular levels of reactive oxygen species (ROS) were also measured. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), estrogen-related receptor-α (Esrra), mitochondrial transcription factor A (TFAM), peroxisome proliferator-activated receptor α (PPARα), and catalase mRNA levels were examined. Results: The expression of AdipoR1 and AdipoR2 was confirmed in rat retina and primary RGCs. AdipoRon significantly increased the survival rate of glutamate-induced cell death and decreased ROS production. Additionally, the mRNA levels of PGC-1α, Esrra, and TFAM were upregulated by AdipoRon. Conclusions: These results suggest that AdipoRon has a neuroprotective effect by inhibiting ROS production via upregulation of PGC-1α, Esrra, and TFAM against glutamate-induced RGC death.