Predictive value of serum MED1 and PGC-1α for bronchopulmonary dysplasia in preterm infants.

OBJECTIVE: This study aimed to predict the bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age(GA) < 32 weeks utilizing clinical data, serum mediator complex subunit 1 (MED1), and serum peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α). METHODS: This prospective observational study enrolled 70 preterm infants with GA < 32 weeks. The infants were categorized into two groups: non-BPD group(N = 35) and BPD group(N = 35), including 25 cases with mild BPD and 10 patients with moderate/severe subgroups. We performed multifactorial regression analysis to investigate the postnatal risk factors for BPD. Furthermore, we compared serum levels of biomarkers, including MED1 and PGC-1α, among infants with and without BPD at postnatal days 1, 7, 14, 28, and PMA 36 weeks. A logistic regression model was constructed to predict BPD's likelihood using clinical risk factors and serum biomarkers. RESULTS: Serum levels of MED1 on the first postnatal day, PGC-1α on the 1st, 7th, and 28th days, and PMA at 36 weeks were significantly lower in the BPD group than in the non-BPD group (P < 0.05). Furthermore, the predictive model for BPD was created by combing serum levels of MED1 and PGC-1α on postnatal day 1 along with clinical risk factors such as frequent apnea, mechanical ventilation time > 7 d, and time to reach total enteral nutrition. Our predictive model had a high predictive accuracy(C statistics of 0.989) . CONCLUSION: MED1and PGC-1α could potentially serve as valuable biomarkers, combined with clinical factors, to aid clinicians in the early diagnosis of BPD.

PPARγ Coactivator-1α Suppresses Metastasis of Hepatocellular Carcinoma by Inhibiting Warburg Effect by PPARγ-Dependent WNT/ß-Catenin/Pyruvate Dehydrogenase Kinase Isozyme 1 Axis.

BACKGROUND AND AIMS: Peroxisome proliferator-activated receptor-gamma (PPARγ) coactivator-1α (PGC1α) is a key regulator of mitochondrial biogenesis and respiration. PGC1α is involved in the carcinogenesis, progression, and metabolic state of cancer. However, its role in the progression of hepatocellular carcinoma (HCC) remains unclear. APPROACH AND RESULTS: In this study, we observed that PGC1α was down-regulated in human HCC. A clinical study showed that low levels of PGC1α expression were correlated with poor survival, vascular invasion, and larger tumor size. PGC1α inhibited the migration and invasion of HCC cells with both in vitro experiments and in vivo mouse models. Mechanistically, PGC1α suppressed the Warburg effect through down-regulation of pyruvate dehydrogenase kinase isozyme 1 (PDK1) mediated by the WNT/ß-catenin pathway, and inhibition of the WNT/ß-catenin pathway was induced by activation of PPARγ. CONCLUSIONS: Low levels of PGC1α expression indicate a poor prognosis for HCC patients. PGC1α suppresses HCC metastasis by inhibiting aerobic glycolysis through regulating the WNT/ß-catenin/PDK1 axis, which depends on PPARγ. PGC1α is a potential factor for predicting prognosis and a therapeutic target for HCC patients.

Effects of Pyrroloquinoline Quinone (PQQ) Supplementation on Aerobic Exercise Performance and Indices of Mitochondrial Biogenesis in Untrained Men.

Objective: Pyrroloquinoline quinone (PQQ) is a novel supplement involved in processes such as mitochondrial biogenesis and cellular energy metabolism. Since endurance exercise and PQQ exhibit similar mechanisms for mitochondrial biogenesis, it is plausible that PQQ may have ergogenic value. Therefore, the purpose of this study was to examine the effects of a six-week endurance exercise training program on mitochondrial biogenesis and aerobic performance in non-endurance-trained males.Methods: Twenty-three males were randomized to consume 20 mg/day of PQQ or placebo (PLC). Both groups followed a supervised six-week endurance exercise training program. Body composition was assessed by dual-energy-x-ray-absorptiometry (DEXA). Aerobic exercise performance and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), a biochemical marker for mitochondrial biogenesis, were assessed before and after the six-week endurance training/supplementation program.Results: There were no significant differences between groups in aerobic performance after endurance-training (p > 0.05). However, there were significant improvements in peak oxygen consumption (VO2peak) and total exercise test duration after endurance-training, irrespective of group (p < 0.05). The PQQ group had a significant increase in PGC-1α protein levels from baseline to post endurance training compared to PLC (p < 0.05). Furthermore, the PQQ group had higher PGC-1α protein levels after 6 weeks of endurance training compared to PLC (p < 0.05).Conclusions: Supplementation of PQQ does not appear to elicit any ergogenic effects regarding aerobic performance or body composition but appears to impact mitochondrial biogenesis by way of significant elevations in PGC-1α protein content.

Peroxisome proliferator-activated receptor gamma co-activator-1 alpha in depression and the response to electroconvulsive therapy.

BACKGROUND: The transcriptional coactivator peroxisome proliferator-activated receptor-γ coactivator (PGC-1α), termed the 'master regulator of mitochondrial biogenesis', has been implicated in stress and resilience to stress-induced depressive-like behaviours in animal models. However, there has been no study conducted to date to examine PGC-1α levels in patients with depression or in response to antidepressant treatment. Our aim was to assess PGC-1α mRNA levels in blood from healthy controls and patients with depression pre-/post-electroconvulsive therapy (ECT), and to examine the relationship between blood PGC-1α mRNA levels and clinical symptoms and outcomes with ECT. METHODS: Whole blood PGC-1α mRNA levels were analysed in samples from 67 patients with a major depressive episode and 70 healthy controls, and in patient samples following a course of ECT using quantitative real-time polymerase chain reaction (qRT-PCR). Exploratory subgroup correlational analyses were carried out to determine the relationship between PGC-1α and mood scores. RESULTS: PGC-1α levels were lower in patients with depression compared with healthy controls (p = 0.03). This lower level was predominantly accounted for by patients with psychotic unipolar depression (p = 0.004). ECT did not alter PGC-1α levels in the depressed group as a whole, though exploratory analyses revealed a significant increase in PGC-1α in patients with psychotic unipolar depression post-ECT (p = 0.045). We found no relationship between PGC-1α mRNA levels and depression severity or the clinical response to ECT. CONCLUSIONS: PGC-1α may represent a novel therapeutic target for the treatment of depression, and be a common link between various pathophysiological processes implicated in depression.

Reduced Gene Expression of Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1α in Whole Blood in Euthyroid Patients One Year After Hemithyroidectomy for Benign Euthyroid Goiter.

We have previously reported decreased thyroid function within the laboratory reference range and changes in mitochondrial function after hemithyroidectomy. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and coactivator-1ß (PGC-1ß) are key regulators of mitochondrial biogenesis and function. The aim was to examine the influence of hemithyroidectomy on the longitudinal change in mRNA expression of these genes. In addition, we measured longitudinal changes in mRNA expressions of the mitochoncrial-related genes nuclear factor erythroid-derived 2-like 2 (NFE2L2), mitochondrial transcription factor A (TFAM), and sodium dismutase 2 (SOD2). Twenty-eight patients were examined before and 1, 3, 6, and 12 months after hemithyroidectomy for benign euthyroid goiter. Thyroid stimulating hormone (TSH) and thyroid hormones were measured, and whole blood gene expression of PGC-1α, PGC-1ß, NFE2L2, TFAM, and SOD2 was examined by reverse transcription quantitative Polymerase Chain Reaction. We used mixed effect regression models to investigate changes in gene expression with time. Averaged over all follow-up visits, TSH increased (p=0.001), tT3 declined (p=0.01), and fT4/tT3 ratio increased (p=0.03) over one-year follow-up, but fT4 remained unchanged. Averaged over all follow-up visits, whole blood PGC-1α levels (p<0.001) and SOD2 (p=0.009) levels declined, but PGC-1ß, TFAM, and NFE2L2 did not change over one-year follow-up. The study demonstrates significant downregulation of whole blood PGC-1α and SOD2 gene expressions in hemithyroidectomized patients with a concomitant increase in TSH concentration within the reference range. Thus, hemithyroidectomized patients may likely have impaired mitochondrial function.

Association between Irisin, hs-CRP, and Metabolic Status in Children and Adolescents with Type 2 Diabetes Mellitus.

Proinflammatory cytokines and the novel myokine irisin, a cleavage product of FNDC5, have been found to play a role in obesity and type 2 diabetes mellitus (T2DM). Irisin has been shown to increase browning of adipose tissue, thermogenesis, energy expenditure, and insulin sensitivity, yet its association with inflammatory markers is still limited. Circulating irisin has been found to be increased in obesity, while in adult subjects with T2DM decreased levels have been found. However, data establishing the association of circulating irisin in children and adolescents with T2DM has not been described in the literature. The objective of this study was to determine irisin plasma concentration and its association with metabolic and adiposity markers and with hs-CRP, a surrogate marker of inflammation used in clinical practice, in a pediatric population with T2DM. A cross-sample of 40 Mexican children and adolescents aged 7-17 were recruited, 20 diagnosed with T2DM and 20 healthy controls. Plasma irisin levels were found to be lower in the T2DM group compared with controls, which could be attributed to a reduced PGC-1α activity in muscle tissue with a consequent decrease in FNDC5 and irisin expression. Irisin concentration was found to be positively correlated with HDL-c, LDL-c, and total cholesterol, while negatively correlated with BMI, waist circumference, and triglycerides. However, after multiple regression analysis, only HDL-c correlation remained significant. hs-CRP was higher in the T2DM group and positively associated with adiposity markers, unfavorable lipid profile, insulin levels, and HOMA-IR, but no association with irisin was found. Given the favorable metabolic effects attributed to irisin, the low plasma levels found in children and adolescents with T2DM could exacerbate the inflammatory and metabolic imbalances and the intrinsic cardiovascular risk of this disease. We propose an "irisin-proinflammatory/anti-inflammatory axis" to explain the role of irisin as a metabolic regulator in obesity and T2DM.

Effects of sprint interval exercise dose and sex on circulating irisin and redox status markers in adolescent swimmers.

Irisin and redox status markers seem to share common pathways of exercise-induced upregulation. The aim of the present study was to assess the effects of sprint interval swimming exercise dose and sex on the circulating levels of irisin and redox status markers in adolescent swimmers. Sixteen male and 16 female adolescent swimmers completed two sets of 4 × 50 m maximal freestyle swimming with a send-off time of 90 s, separated by 10 min of passive recovery. Venous blood samples were obtained pre-exercise (Pre), after the first set (Post1) and after the second set (Post2). Males had higher irisin levels than females. Reduced glutathione (GSH, µmol g Hb-1) increased from 8.6 (2.2) [pooled males and females, mean (SD) throughout] at Pre to 9.4 (2.1) at Post1 and Post2. Total antioxidant capacity (µmol DPPH mL-1) increased from 0.89 (0.17) at Post1 to 0.94 (0.16) at Post2. 8-hydroxy-2´-deoxyguanosine (ng mL-1) increased from 20.9 (6.9) at Pre and 21.5 (7.1) at Post1 to 25.0 (10.9) at Post2. Overall, sprint interval swimming exercise induced small but potentially effective changes in the studied parameters. Exercise dose influenced the GSH and 8-OHdG responses, and sex affected irisin levels.

Vitamin D Status and Resting Metabolic Rate May Modify through Expression of Vitamin D Receptor and Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1 Alpha Gene in Overweight and Obese Adults.

BACKGROUND: Resting metabolic rate (RMR) used to prognosticate and measure the amount of energy required. Vitamin D is known as a new predictor of RMR. The aim of this study is to investigate the relationship between vitamin D effects on RMR in connection with the vitamin D receptor (VDR) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) gene expression. METHODS: We enrolled 298 overweight and obese adults in this cross-sectional study. Body mass index (BMI), fat mass, fat-free mass, insulin level, visceral fat, and vitamin D status were assessed. RMR was measured by means of indirect calorimetry. The real-time polymerase chain reaction using specific primer pairs for VDR and PGC-1α was performed. RESULTS: There were significant differences in terms of fat free mass, fat percentage, insulin levels, RMR/kg body weight, and RMR/BMI, VDR, and PGC-1α among participants were categorized based on the vitamin D status. But after using general linear model for adjusting, all significant results missed their effectiveness except RMR/kg body weight and VDR. Linear regression analysis used to show the mediatory role of VDR and PGC-1α on the RMR/kg body weight and vitamin D status relationship. Our results showed that VDR had a mediatory effect on the relationship between RMR/kg body weight and vitamin D status (ß = 0.38, 95% CI -0.48 to 1.60; ß = -1.24, 95% CI -5.36 to 1.70). However, PGC-1α did not affect the relationship between RMR/kg body weight and vitamin D status (ß = 0.50, 95% CI = -0.02 to 3.42; ß = 0.59, 95% CI 0.14-3.90). CONCLUSION: Our study showed the mediatory effect of VDR gene expression in the association of 25(OH)2D plasma levels and resting metabolic rate among obese individuals.

Beneficial effects of omega-3 and vitamin E coadministration on gene expression of SIRT1 and PGC1α and serum antioxidant enzymes in patients with coronary artery disease.

BACKGROUND AND AIM: SIRT1 and PGC1α are two important genes, which play critical roles in regulating oxidative stress and inflammation processes. The study aimed assess the effects of coadministration of omega-3 and vitamin E supplements on SIRT1 and PGC1α gene expression and serum levels of antioxidant enzymes in coronary artery disease (CAD) patients. METHODS AND RESULTS: Participants of this randomized controlled trial included 60 CAD male patients who were categorized into three groups: Group 1 received omega-3 (4 g/day) and vitamin E placebo (OP), group 2 omega-3 (4 g/day) and vitamin E (400 IU/day; OE), and group 3 omega-3 and vitamin E placebos (PP) for 2 months. Gene expression of SIRT1 and PGC1α in peripheral blood mononuclear cells (PBMCS) was assessed by reverse transcription polymerase chain reaction (RT-PCR). Furthermore, serum antioxidant enzyme and high-sensitivity C-reactive protein (hsCRP) levels were assessed at the beginning and end of the intervention. Gene expression of SIRT1 and PGC1α increased significantly in the OE group (P = 0.039 and P = 0.050, respectively). Catalase and hsCRP levels increased significantly in the OE and OP groups. However, glutathione peroxidase (GPX) and superoxide dismutase (SOD) levels did not statistically change in all groups. The total antioxidant capacity (TAC) increased significantly in the OE group (P = 0.009) but not in OP and PP groups. CONCLUSION: Supplementation of omega-3 fatty acids in combination with vitamin E may have beneficial effects on CAD patients by increasing gene expression of SIRT1 and PGC1α and improving oxidative stress and inflammation in these patients.

Serum Mitochondrial Quality Control Related Biomarker Levels are Associated with Organ Dysfunction in Septic Patients.

BACKGROUND: To investigate the feasibility and the value of using mitochondrial quality control (MQC)-related proteins as biomarkers in septic patients. METHODS: The enrolled subjects were divided into four groups: healthy control group (n = 30), intensive care unit (ICU) control group (n = 62), septic nonshock group (n = 40), and septic shock group (n = 94). Serum levels of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), fission protein 1 (Fis1), mitofusin2 (Mfn2), and Parkin were measured by enzyme-linked immunosorbent assay at the time of enrollment for all groups. Clinical parameters and laboratory test results were also collected. RESULTS: The levels of MQC-related biomarkers between any two of the four groups were significantly different (P < 0.001 for all). The serum levels of PGC-1α, Mfn2, and Parkin were lowest in healthy individuals; the levels were dramatically higher in the ICU control group compared with the others, and they decreased progressively from the septic nonshock group to the septic shock group. However, the pattern for Fis1 was inverse; the more severe the condition was, the higher the level of Fis1. Moreover, there was moderate correlation between MQC-related biomarkers and the SOFA score (PGC-1α, r = -0.662; Fis1, r = 0.609; Mfn2, r = -0.677; Parkin, r = 0.-0.674, P < 0.001 for all). CONCLUSIONS: The serum levels of PGC-1α, Fis1, Mfn2, and Parkin were significantly correlated with organ dysfunction and reflected the disease progression and severity. The dynamic surveillance of these four biomarkers could be beneficial to predict outcome and guide treatment.

Protective role of emodin in rats with post-myocardial infarction heart failure and influence on extracellular signal-regulated kinase pathway.

We aimed to explore the effects of emodin on the energy metabolism of myocardial cells in rats with post-myocardial infarction (MI) heart failure (HF) and the extracellular signal-regulated kinase (ERK) pathway. The model of MI was established by ligation of the left anterior descending branch. After 4 weeks, the rats with left ventricular ejection fraction (LVEF) of ≤45% were used aspost-MI HF model animals and randomly divided into model, low-dose, middle-dose, high-dose and control groups (n=10). Low-, middle- and high-dose groups were gavaged with 20 mg/kg, 40 mg/kg and 60 mg/kg emodin daily, respectively. After administration for 14 d, the changes in LVEF, left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD) and interventricular septum thickness (IVS) were analyzed. The apoptosis rate of myocardial cells was detected by TUNEL staining. The levels of serum cardiac troponin I (cTnI) and peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1) were determined using ELISA, and the expressions of mitochondrial respiratory chain complex I protein and phosphorylated-ERK (p-ERK) in myocardial tissues were determined by Western blotting.  Compared with model group, LVEDD, LVESD, apoptosis rate of myocardial cells, levels of serum cTnI and PGC-1, and expressions of complex I and p-ERK in myocardial tissues significantly decreased, while LVEF and IVS increased in low-dose, middle-dose, high-dose and control groups (P<0.05). The changes in the above indices were significantly dependent on the dose of emodin (P<0.05).Emodin can significantly relieve post-MI HF, reduce the apoptosis rate of myocardial tissues, and ameliorate the cardiac function of rats.

Expression of LEP, LEPR and PGC1A genes is altered in peripheral blood mononuclear cells of patients with relapsing-remitting multiple sclerosis.

Leptin (LEP) may contribute to the pathogenesis of multiple sclerosis (MS) by its immunomodulatory, proinflammatory and prooxidant effects. Therefore, plasma LEP levels and mRNA expression of five genes related to the LEP signaling pathway (LEP, LEP receptor (LEPR), peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC1A), superoxide dismutase 2, tumor necrosis factor-alpha) were investigated in relapsing-remitting MS. In patients (N = 64), compared to healthy subjects (N = 62), relative LEP mRNA levels were significantly increased (p = 0,01), while LEPR and PGC1A mRNA levels were decreased (p = 0,001 and p = 0,04, respectively). Significant positive correlation was observed between LEPR mRNA levels and clinical parameters of MS progression (EDSS, MSSS).

Elevation of serum oxidative stress in patients with retina vein occlusions.

PURPOSE: Retina vein occlusion (RVO) is a visual-threatening retinal disease that causes irreversible impaired quality of life. The contribution of oxidative stress behind clinical course of RVO was rarely investigated. The study aimed to measure the serum oxidative biomarker in patients with RVO to investigate further physical response. METHODS: We measured the serum levels of malondialdehyde (MDA), 8-hydroxy-2-deoxyguanosine (8OHdG), Sirutin 1 (SIRT1), peroxisome proliferator- activated receptor gamma (PPAR-r), Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), orkhead box protein O1 (FOXO1), orkhead box protein O3 (FOXO3), catalase, (SOD) and hydrogen peroxide (H2 O2 ) among 19 patients with cataract as control group and 36 patients with RVO, respectively. RESULTS: The mean MDA, 8OHdG and hydrogen peroxide in the serum were significantly higher in patients with RVO compared with the results in control group subjects. Whereas SIRT1, PPAR-r, PGC-1, FOXO1, FOXO3, catalase and SOD levels in serum were significantly decreased in patients with RVO compared with control group. CONCLUSION: We demonstrated that the serum level of MDA, 8OHdG and hydrogen peroxide is increased in patients with RVO. Among these, the elevation of MDA, 8OHdG and hydrogen peroxide suggests the increasing of serum oxidative stress in RVO patients. All enzymes related reactive oxygen species scavenge were decreased. Thus, focal RVO may increase systemic oxidative stress within serum.

Association of the Gly482Ser PPARGC1A gene variant with different cholesterol outcomes in response to two energy-restricted diets in subjects with excessive weight.

OBJECTIVES: The aim of this study was to investigate the influence of two PPARGC1A gene polymorphisms on metabolic outcomes in response to two energy-restricted diets. METHODS: A 4-mo nutritional intervention was conducted that involved two different hypo-energetic diets based on low-fat (LF) and moderately high-protein (MHP) dietary patterns. Unrelated subjects with excessive weight were genotyped for two PPARGC1A polymorphisms: Rs8192678 (Gly482Ser) and rs3755863 (G > A). Genotyping was performed by next-generation sequencing and haplotypes were screened. Anthropometric measurements and biochemical tests were assessed with standardized methods. RESULTS: Different cholesterol outcomes were observed by diet and Gly482Ser genotype. The Gly482 Gly homozygotes after an LF diet had lower reductions in total cholesterol (-9 mg/dL vs. -27 mg/dL; P = 0.017) and low-density lipoprotein cholesterol levels (-5 mg/dL vs. -18 mg/dL; P = 0.016) than the subjects who were carriers of 482 Ser allele. However, this finding was not recorded in the MHP group where Gly482 Gly homozygotes underwent similar cholesterol decreases as the 482 Ser allele carriers. Likewise, all genotype carriers had significant reductions in the frequencies of hypercholesterolemia (total cholesterol ≥200 mg/dL) except for Gly482 Gly homozygotes in the LF group. Meanwhile, the rs3755863 polymorphism and PPARGC1A haplotypes showed borderline effects with regard to cholesterol decreases. CONCLUSIONS: An energy-restricted MHP diet might be more beneficial than an LF diet to reduce serum cholesterol among subjects who are carriers of the PPARGC1A Gly482Gly genotype. The analysis of this genetic variant might be the basis for a precise, nutrigenetic management of hypercholesterolemia based on genetic makeup.

Expression of the gene coading for PGC-1α in peripheral blood leukocytes and related gene variants in patients with Parkinson's disease.

INTRODUCTION: Peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α) plays an important role in Parkinson's disease (PD). The aim of the study was to evaluate PGC-1α gene expression in the peripheral blood of PD patients. We also investigated PGC-1α-related gene variants and identified whether they are associated with PGC-1α gene expression. METHODS: 259 PD patients and 253 healthy controls were included in this study. PPARGC1A (the gene encoding PGC-1α) expression levels were tested using real-time PCR. Single nucleotide polymorphisms (SNPs) of the PGC-1α-related genes (PPARGC1A, PPARG and SIRT1) were genotyped by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). RESULTS: PPARGC1A levels were significantly decreased in PD patients (P = 0.000) and negatively correlated with the patients' H&Y stage (r = -0.212, P = 0.039) and UPDRS-III score (r = -0.208, P = 0.044), after correcting, these correlations disappeared. The genotype frequencies of PGC-1α-related gene variants were not associated with the risk of PD. PPARGC1A rs2970870 variant was associated with the NMS score (P = 0.026), SIRT1 rs7895833 variant was associated with HAMA score (P = 0.029). PPARG rs4684847 variant was associated with MMSE score (P = 0.031). PPARG rs1801282, rs4684847, rs3856806 variants were associated with MoCA score. After correcting, only the association between PPARG rs4684847 and MoCA score remained significant (FDR = 0.048). PGC-1α-related gene variants had no effect on PGC-1α gene expression. CONCLUSION: The decreased expression of PGC-1α may not be due to its related gene variants. PGC-1α could become a candidate blood-based biomarker for diagnosis and monitoring disease progression.

Variants in the PPARGC1A Gene may Influence the Effect of Fat Intake on Resting Metabolic Rate in Obese Women.

Recent studies have shown that dietary intake and genetic variants play a decisive role in the risk of obesity. Therefore, this study was designed to examine the interaction between dietary fat and PPARGC1A polymorphisms on the level of resting metabolic rate (RMR). We enrolled 288 Iranian overweight and obese women in this cross-sectional study. We sequenced the 648 b.p. DNA in Exon 8 of PPARGC1A gene. We analyzed the two single-nucleotide polymorphisms, namely rs11290186 and rs2970847, in this region. All participants were assessed for RMR, dietary intake, and body composition. This study demonstrated that total cholesterol and insulin levels were positively associated with T allele carriers of rs2970847. Moreover, the A-deletion allele carrier of the rs11290186 genotype had higher triacylglycerol and insulin concentrations. The current study revealed that, after adjustment for energy intake, the AA genotype of PPARGC1A (rs11290186) had a direct association with polyunsaturated fatty acids and linoleic acid intakes. Another important finding in our study was that there was an interaction seen between fat and saturated fatty acids intake with the PPARGC1A genotypes. Women with fat intakes of more than 30% of calorie intake per day and the A-deletion genotype had a lower RMR and RMR/fat free mass (FFM). It seems that the PPARGC1A polymorphisms lead to the downregulation of insulin signaling and subsequently insulin resistance. In addition, the interactions between the PPARGC1A polymorphisms (rs11290186) and the level of dietary fat intake probably can have an effect on RMR and RMR/FFM in obese women.

Epigenetic regulation of an adverse metabolic phenotype in polycystic ovary syndrome: the impact of the leukocyte methylation of PPARGC1A promoter.

OBJECTIVE: To investigate PPARGC1A promoter methylation and mitochondria DNA (mtDNA) content in the leukocytes of women with polycystic ovary syndrome (PCOS) and analyze the relationship between these indices and metabolic risk for women with PCOS. DESIGN: Cross-sectional study. SETTING: University hospital. PATIENT(S): A total of 175 women with PCOS and 127 healthy controls. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Women with and without PCOS classified using the typical metabolic risk criteria of the National Cholesterol Education Program's Adult Treatment Panel III report (ATPIII), methylation of PPARGC1A promoter tested by methylation-specific polymerase chain reaction, and mtDNA content confirmed by quantitative polymerase chain reaction (PCR). RESULT(S): PPARGC1A promoter methylation was specifically increased, but mtDNA content was specifically decreased in women with PCOS compared with the control women after adjustment for body mass index. Moreover, in women with PCOS who have increased metabolic risk, the differences in PPARGC1A promoter methylation and mitochondrial content were aggravated. CONCLUSION(S): In conclusion, PPARGC1A promoter methylation and mitochondrial content were found to be potential biomarkers for the prediction of metabolic risk in women with PCOS.

Effects of Running Wheel Activity and Dietary HMB and ß-alanine Co-Supplementation on Muscle Quality in Aged Male Rats.

OBJECTIVE: Loss of skeletal muscle function is linked to increased risk for loss of health and independence in older adults. Dietary interventions that can enhance aging muscle function, alone or in combination with exercise, may offer an effective way to reduce these risks. The goal of this study was to evaluate the muscular effects of beta-hydroxy-beta-methylbutyrate (HMB) and beta-alanine (ß-Ala) co-supplementation in aged Sprague-Dawley rats with voluntary access to running wheels (RW). METHODS: Aged (20 months) rats were housed with ad libitum access to RW while on a purified diet for 4 weeks, then balanced for RW activity and assigned to either a control or an experimental diet (control + HMB and ß-Ala) for the next 4 weeks (n = 10/group). At the end of the study, we assessed muscle size, in situ force and fatigability in the medial gastrocnemius muscles, as well as an array of protein markers related to various age- and activity-responsive signaling pathways. RESULTS: Dietary HMB+ß-Ala did not improve muscle force or fatigue resistance, but a trend for increased muscle cross-sectional area (CSA) was observed (P = 0.077). As a result, rats on the experimental diet exhibited reduced muscle quality (force/CSA; P = 0.032). Dietary HMB+ß-Ala reduced both the abundance of PGC1-α (P = 0.050) and the ratio of the lipidated to non-lipidated forms of microtubule-associated protein 1 light chain 3 beta (P = 0.004), markers of mitochondrial biogenesis and autophagy, respectively. Some alterations in myostatin signaling also occurred in the dietary HMB+ß-Ala group. There was an unexpected difference (P = 0.046) in RW activity, which increased throughout the study in the animals on the control diet, but not in animals on the experimental diet. CONCLUSIONS: These data suggest that the short-term addition of dietary HMB+ß-Ala to modest physical activity provided little enhancement of muscle function in this model of uncomplicated aging.

Effect of thyme extract supplementation on lipid peroxidation, antioxidant capacity, PGC-1α content and endurance exercise performance in rats.

BACKGROUND: Athletes have a large extent of oxidant agent production. In the current study, we aimed to determine the influence of thyme extract on the endurance exercise performance, mitochondrial biogenesis, and antioxidant status in rats. METHODS: Twenty male Wistar rats were randomly divided into two groups receiving either normal drinking water (non-supplemented group, n = 10) or thyme extract, 400 mg/kg, (supplemented group, n = 10). Rats in both groups were subjected to endurance treadmill training (27 m/min, 10% grade, 60 min, and 5 days/week for 8 weeks). Finally, to determine the endurance capacity, time to exhaustion treadmill running at 36 m/min speed was assessed. At the end of the endurance capacity test, serum and soleus muscle samples were collected and their superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, as well as malondialdehyde (MDA) concentration were measured. Protein expression of PGC-1α, as a marker of mitochondrial biogenesis, was also determined in the soleus muscle tissue by immunoblotting assay. RESULTS: Findings revealed that the exhaustive running time in the treatment group was significantly (p < 0.05) prolonged. Both serum and soleus muscle MDA levels, as an index of lipid peroxidation, had a threefold increase in the thyme extract supplemented group (t18 = 8.11, p < 0.01; t18 = 4.98, p < 0.01 respectively). The activities of SOD and GPx of the soleus muscle were significantly (p < 0.05) higher in the non-supplemented group, while there was no significant difference in serum SOD, GPx activities, and total antioxidant capacity between groups. Furthermore, thyme supplementation significantly (p < 0.05) decreased PGC-1α expression. CONCLUSIONS: Thyme extract supplementation increased endurance exercise tolerance in intact animals, although decrease of oxidative stress and regulation of the PGC-1α protein expression are not considered as underlying molecular mechanisms.

Prognostic value of plasma levels of HIF-1a and PGC-1a in breast cancer.

Cellular adaptive mechanisms are crucial for tumorigenesis and a common feature in solid tumor progression. Hypoxia-inducible factor-1α (HIF-1α) facilitates the biological response to hypoxia, advancing angiogenesis and metastatic potential of the tumor. The peroxisome proliferator-activated receptor γ coactivators 1α (PGC-1α) enhances mitochondrial biogenesis, favored by migratory/invasive cancer cells. We conducted a prospective, long-term follow up study to determine whether HIF-1α and PGC-1α can be implemented as predictive biomarker in breast cancer. HIF-1α and PGC-1α plasma concentrations were measured in patients and in healthy controls by enzyme linked immune sorbent assay. Breast cancer patients had significantly higher HIF-1α and PGC-1α levels, which correlated with clinicopathological features, overall with more aggressive cancer characteristics. Disease free and overall survival of breast cancer patients with high HIF-1α and PGC-1α were significantly poorer than in patients with low plasma levels. In multivariate analysis, high amount of PGC-1α showed independent prognostic value. Our data suggests that HIF-1α and PGC-1α may be promising, noninvasive, biomarkers with a high potential for future clinical implication to identify subgroups of patients with poorer prognosis and to indicate early, subclinical metastasis.