PGC-1α Research Articles

Theobromine enhances the conversion of white adipocytes into beige adipocytes in a PPARγ activation-dependent manner

The adipocytes play an important role in driving the obese-state—white adipose tissue (WAT) stores the excess energy as fat, wherein brown adipose tissue (BAT) is responsible for energy expenditure via the thermoregulatory function of uncoupling protein 1 (UCP1)—the imbalance between these two onsets obesity. Moreover, the anti-obesity effects of brown-like-adipocytes (beige) in WAT are well documented. Browning, the process of transformation of energy-storing into energy-dissipating adipocytes, is a potential preventive strategy against obesity and its related diseases. In the present study, to explore an alternative source of natural products in the regulation of adipocyte transformation, we assessed the potential of theobromine (TB), a bitter alkaloid of the cacao plant, inducing browning in mice (in vivo) and primary adipocytes (in vitro). Dietary supplementation of TB significantly increased skin temperature of the inguinal region in mice and induced the expression of UCP1 protein. It also increased the expression levels of mitochondrial marker proteins in subcutaneous adipose tissues but not in visceral adipose tissues. The microarray analysis showed that TB supplementation upregulated multiple thermogenic and beige adipocyte marker genes in subcutaneous adipose tissue. Furthermore, in mouse-derived primary adipocytes, TB upregulated the expression of the UCP1 protein and mitochondrial mass in a PPARγ ligand-dependent manner. It also increased the phosphorylation levels of PPARγ coactivator 1α without affecting its protein expression. These results indicate that dietary supplementation of TB induces browning in subcutaneous WAT and enhances PPARγ-induced UCP1 expression in vitro, suggesting its potential to treat obesity.

Standardized Hydrangea serrata (Thunb.) Ser. Extract Ameliorates Obesity in db/db Mice.

We previously reported the potential anti-obesity effects of the water extract of Hydrangea serrata (Thunb.) Ser. leaves (WHS) in high-fat diet-induced obese mice. As an extension of our previous study, we investigated the anti-adipogenic and anti-obesity effects of WHS and its underlying molecular mechanisms in 3T3-L1 preadipocytes and genetically obese db/db mice. WHS attenuated the gene expression of adipogenic transcription factors, CCAAT/enhancer binding protein (C/EBP)α, peroxisome proliferator-activated receptor (PPAR)γ, and sterol regulatory element binding protein (SREBP)-1. Moreover, WHS inhibited the mitotic clonal expansion of preadipocytes by inducing G1 cell cycle arrest. Oral administration of WHS alleviated body weight gain and body fat accumulation in vivo. In addition, adipocyte hypertrophy and liver steatosis were ameliorated by WHS treatment. WHS reduced C/EBPα, PPARγ, and SREBP-1 expression and activated AMPKα phosphorylation in both white adipose tissue (WAT) and liver tissue. WHS also mildly upregulated the expression of thermogenic proteins, including uncoupling protein-1, PPARs, PPARγ coactivator-1α, and sirtuin-1, in brown adipose tissue (BAT). Furthermore, WHS altered the gut microbiota composition to resemble that of wild-type mice. Taken together, our findings suggest that WHS could alleviate adiposity by inhibiting adipogenesis in WAT and the liver and modulating the gut microbiota.

Evaluation of Frequency of PGC1-α and CKMM Genes Polymorphisms Among Iranian Elite Hockey Athletes

Background: Physical activity is a complex phenotype influenced by millions of genes and environmental factors. It is well known that physical performance and sports ability are linked to genes variations. Objectives: The aim of this study was to evaluate the frequency of PGC1-α and CKMM gene polymorphisms in elite hockey athletes. Methods: Fifty Iranian elite national hockey athletes and 100 non-athletes participated in this study. To determine the genotypes of PGC1-α and CKMM gene polymorphisms, 2 mL of saliva was sampled and used for DNA extraction. To determine the genotypes, the PCR-RFLP method was employed. After examining the variants, the allele and genotype frequencies of subjects were measured. Results: The results showed no significant differences for the PPARGC1A gene in the percentage of AA, GG, and AG genotypes. Similarly, the percentage of these genotypes of the CKMM gene did not differ significantly between athletes and non-athletes. Conclusions: The results suggest that the gene polymorphisms of PGC1-α and CKMM are the same between the Iranian elite hockey athletes and non-athletes, which may be due to the overlapping effect of other genes and/or the small sample size of the study.

Effect of dietary leucine supplementation on skeletal muscle fiber type transformation in weaning piglets

To investigate the effects of dietary leucine supplementation on muscle fiber type transformation in weaning piglets, 54 21-day-old male DLY (Duroc × Landrace × Yorkshire) weaned piglets were randomly divided into control, 0.25% and 0.5% leucine groups. The experiment lasted for 42 d. The results showed that dietary supplementation of 0.25% leucine significantly increased the protein expressions of slow MyHC, myoglobin and Troponin I-SS and the mRNA expressions of MyHC I, MyHC IIa, Tnni1, Tnnc1, Tnnt1 and myoglobin, while decreased the protein level of fast MyHC and the mRNA level of MyHC IIb in longissimus dorsi (LD) muscle. Furthermore, 0.25% leucine significantly increased succinic dehydrogenase (SDH) activity and decreased lactate dehydrogenase (LDH) activity. In addition, our data found that 0.25% leucine significantly increased serum adiponectin (AdipoQ) concentration, and the protein levels of AdipoQ, adiponectin receptor 1 (AdipoR1), phosphorylated AMP-activated protein kinase (p-AMPK) and PPAR-γ coactivator-1α (PGC-1α) and the mRNA levels of AdipoQ, AdipoR1 and AMPKα2. Together, our findings indicate that leucine promotes porcine skeletal muscle fiber type transformation from fast-twitch to slow-twitch, and the effect may be mediated by AdipoQ-AMPK-PGC-1α signaling pathway.

NAD+ improves cognitive function and reduces neuroinflammation by ameliorating mitochondrial damage and decreasing ROS production in chronic cerebral hypoperfusion models through Sirt1/PGC-1\u03b1 pathway

BackgroundMicroglial-mediated neuroinflammation plays an important role in vascular dementia, and modulating neuroinflammation has emerged as a promising treatment target. Nicotinamide adenine dinucleotide (NAD+) shows anti-inflammatory and anti-oxidant effects in many neurodegenerative disease models, but its role in the chronic cerebral hypoperfusion (CCH) is still unclear.MethodsThe bilateral common carotid artery occlusion (BCCAO) was performed to establish CCH models in Sprague-Dawley rats. The rats were given daily intraperitoneal injection of NAD+ for 8 weeks. The behavioral test and markers for neuronal death and neuroinflammation were analyzed. Mitochondrial damage and ROS production in microglia were also assessed. RNA-seq was performed to investigate the mechanistic pathway changes. For in vitro studies, Sirt1 was overexpressed in BV2 microglial cells to compare with NAD+ treatment effects on mitochondrial injury and neuroinflammation.ResultsNAD+ administration rescued cognitive deficits and inhibited neuroinflammation by protecting mitochondria and decreasing ROS production in CCH rats. Results of mechanistic pathway analysis indicated that the detrimental effects of CCH might be associated with decreased gene expression of PPAR-γ co-activator1α (PGC-1α) and its upstream transcription factor Sirt1, while NAD+ treatment markedly reversed their decrease. In vitro study confirmed that NAD+ administration had protective effects on hypoxia-induced neuroinflammation and mitochondrial damage, as well as ROS production in BV2 microglia via Sirt1/PGC-1α pathway. Sirt1 overexpression mimicked the protective effects of NAD+ treatment in BV2 microglia.ConclusionsNAD+ ameliorated cognitive impairment and dampened neuroinflammation in CCH models in vivo and in vitro, and these beneficial effects were associated with mitochondrial protection and ROS inhibition via activating Sirt1/PGC-1α pathway.

Postnatal exercise protects offspring from high-fat diet-induced reductions in subcutaneous adipocyte beiging in C57Bl6/J mice

Maternal low-protein and postnatal high-fat (HF) diets program offspring obesity and type 2 diabetes mellitus (T2DM) risk by epigenetically reducing beige adipocytes (BAs) via increased G9a protein expression (Histone3 Lysine9 dimethyl transferase), an inhibitor of the BA marker fibroblast growth factor 21 (FGF21). Conversely, offspring exercise reduces fat mass and white adipocytes, but the mechanisms are not yet understood. This work investigated whether exercise reduces offspring obesity and T2DM risk caused by a maternal HF diet via regulation of G9a and FGF21 expression that would convert white to BA. Two-month-old female C57Bl/6J mice (F0) were fed a 16% (normal fat; NF) or a 45% HF diet for 3 months prior to breeding, and subsequent gestation and lactation. Male offspring (F1) were fed the same NF and HF diets and further divided into either sedentary (S) or voluntary wheel running (Ex) groups for an additional 3 months yielding eight groups: NF (maternal treatment condition)-NF-S (postweaning treatment conditions), NF-HF-S, NF-NF-Ex, NF-HF-Ex, HF-NF-S, HF-HF-S, HF-NF-Ex, and HF-HF-Ex. Subcutaneous adipose tissue was collected for protein and mRNA analysis of FGF21, peroxisome proliferator-activated receptor-gamma coactivator (PGC-1 alpha, inducer of FGF21), G9a, E4BP4 (G9a coactivator), and protein expression of H3K9 demethylases (KDM4C). Postnatal HF diet decreased FGF21 positive BA numbers regardless of maternal diets and postnatal exercise. Under sedentary conditions, postnatal HF diet increased protein expression of FGF21 transcription inhibitors G9a and E4BP4 compared to NF diet resulting in decreased FGF21 expression. In contrast, postnatal HF diet and exercise decreased G9a and E4BP4 protein expression while decreasing FGF21 expression compared to NF diet. Under exercised condition, postnatal HF diet-induced KDM4C protein expression while no changes in KDM4C protein expression were induced by postnatal HF diet under sedentary conditions. These findings suggest that the postnatal diet exerts a greater impact on offspring adiposity and BA numbers than maternal diets. These data also suggest that offspring exercise induces KDM4C to counter the increase in G9a that was triggered by maternal and postnatal HF diets. Future studies need to determine whether KDM4C induces methylation status of G9a to alter thermogenic function of BA.

Low Birth Weight Disturbs the Intestinal Redox Status and Mitochondrial Morphology and Functions in Newborn Piglets.

Simple SummaryLow birth-weight piglets normally have a higher growth retardation and are more prone to disease such as diarrhea compared to NBW piglets, which are strongly associated with intestinal health, body redox status and mitochondrial morphology and function. The present study showed that low birth-weight piglets exhibited abnormal intestinal development and impaired intestinal barrier function and redox status when compared to normal- birth-weight piglets. Furthermore, we found that the impaired mitochondrial structure and functions may be one of the main causes of intestinal dysfunction in low birth-weight piglets. These results provided insights for the mechanisms of intestinal dysfunction in low birth-weight piglets.Low birth-weight (LBW) neonates exhibit a lower growth rate and impaired intestinal development. However, the reasons for abnormal development of small intestine in LBW piglets have not been widely studied. The present study focused on the redox status and mitochondrial morphology and functions of the small intestine in LBW newborn piglets. Ten newborn normal birth-weight (NBW) piglets and LBW piglets from 10 primiparous sows with the same parturition day were selected and sampled immediately without sucking colostrum. The small intestine tissues were collected and measured. Compared with NBW newborn piglets, LBW newborn piglets had a significantly decreased length and weight of the small intestine (p < 0.05) as well as the villus height/crypt depth (V/C) index in the jejunum (p < 0.05). Furthermore, LBW piglets had a lower gene expression of tight junction protein zonula occluden-1 (ZO1), claudin 1, antioxidant enzyme catalase (CAT), glutathione peroxidase (GPX) and heme oxygenase-1 (HO-1) in jejunum (p < 0.05). Meanwhile, LBW induced mitochondrial vacuolation and significantly decreased the mRNA expression of PPARγ coactivator-1α (PGC-1α) (p < 0.05) and tended to decrease the expression of cytochrome coxidase IV (Ccox IV) (p = 0.07) and cytochrome C (Cytc) (p = 0.08). In conclusion, LBW newborn piglets showed an abnormal development of the small intestine and disturbed redox status, and this may be caused by impaired morphology and the functions of mitochondria in the jejunum.

Positive regulation of TFEB and mitophagy by PGC-1α to alleviate LPS-induced acute lung injury in rats

Aim of the studyAcute lung injury (ALI) exhibits the features of noncardiogenic pulmonary edema and acute inflammatory process, and it also displays significant morbidity and mortality rates. This work focused on identifying how overexpression of PPARγ coactivator 1α (PGC-1α) positively regulated TFEB and mitophagy for resisting the lipopolysaccharide (LPS)-mediated ALI. Materials and methodsThe levels of autophagic proteins and inflammatory factors in LPS-induced ALI rats and primary type II alveolar epithelial cells were measured, respectively. Lung wet/dry ratios were calculated. Protein co-immunoprecipitation of PGC-1α and TFEB was detected. To explore the interaction between TFEB and PGC-1α, a luciferase reporter assay was conducted. ResultsThe results showed that overexpression of PGC-1α decreases IL-1 and IL-6 but increases IL-10 in LPS-mediated ALI rats and type II alveolar epithelial cells (P < 0.05). Overexpression of PGC-1α can reduce lung edema in LPS-mediated ALI rats (P < 0.05). Overexpression of PGC-1α upregulates mitophagy-related proteins, such as TFEB, LC3B, Beclin, and LAMP1, and improves mitophagy in LPS-induced ALI. Protein immunoprecipitation indicated that TFEB and PGC-1α are interacting proteins. The luciferase reporter assay demonstrated that PGC-1α positively regulated TFEB in the LPS-induced primary type II alveolar epithelial cells. ConclusionPGC-1α protects LPS-induced ALI by decreasing inflammation and alleviating lung edema. The mechanism might be positive regulation of TFEB directly and then upregulation of mitophagy in LPS-induced ALI.

Nobiletin Attenuates Pathological Cardiac Remodeling after Myocardial Infarction via Activating PPARγ and PGC1α.

Materials and Methods C57BL/6 mice were treated with coronary artery ligation to generate an MI model, followed by treatment for 3 weeks with NOB (50 mg/kg/d) or vehicle (50 mg/kg/d), with or without the peroxisome proliferator-activated receptor gamma (PPARγ) inhibitor T0070907 (1 mg/kg/d). Cardiac function (echocardiography, survival rate, Evans blue, and triphenyl tetrazolium chloride staining), fibrosis (Masson's trichrome staining, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot (WB)), hypertrophy (haematoxylin-eosin staining, wheat germ agglutinin staining, and qRT-PCR), and apoptosis (WB and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) staining) were evaluated. Hypoxia-induced apoptosis (TUNEL, WB) and phenylephrine- (PE-) induced pathological hypertrophy (immunofluorescence staining, qRT-PCR) models were established in primary neonatal rat ventricular myocytes (NRVMs). The effects of NOB with or without T0070907 were examined for the expression of PPARγ and PPARγ coactivator 1α (PGC1α) by WB in mice and NRVMs. The potential downstream effectors of PPARγ were further analyzed by WB in mice. Results Following MI in mice, NOB intervention enhanced cardiac function across three predominant dimensions of pathological cardiac remodeling, which reflected in decreasing cardiac fibrosis, apoptosis, and hypertrophy decompensation. NOB intervention also alleviated apoptosis and hypertrophy in NRVMs. NOB intervention upregulated PPARγ and PGC1α in vivo and in vitro. Furthermore, the PPARγ inhibitor abolished the protective effects of NOB against pathological cardiac remodeling during the progression from MI to CHF. The potential downstream effectors of PPARγ were nuclear factor erythroid 2-related factor 2 (Nrf-2) and heme oxygenase 1 (HO-1). Conclusions Our findings suggested that NOB alleviates pathological cardiac remodeling after MI via PPARγ and PGC1α upregulation.

Exercise Mimetics: Fact Or Fantasy?

The abundant health benefits of physical exercise are not being translated into practice. In an effort to short circuit the need for physical activity to promote health, exercise-mimetic agents are being developed; they mimic the action of peptide molecules released from exercised muscles. The intention is to mimic biochemi-cal responses even without performing exercise. Technologies have advanced to identify various exercise-induced proteins, called myokines, and to develop ligands which bind to the myokine receptors. A number of such chemicals exist that mimic the effects of activating Peroxisome proliferator-activated receptor-γ (PPARγ) coactivator 1α (PGC-1 α), Peroxisome proliferator-activated receptor β/δ (PPAR β/δ) and AMP-activated protein kinase (AMPK). Most such agents were test-ed in animal models with varying degrees of success and mostly undesirable ad-verse effects. The increasing complexity of exercise response is being recognized, making the development and use of single ‘exercise-mimetics’ ineffective, except for some narrow indications. In addition, some of the performance enhancing ex-ercise-mimetics are being misused by endurance athletes, with the chemicals be-ing banned as doping agents. In a fascinating interaction between physiology and pharmacology, agents that can mimic the beneficial effects of physical exercise are an enticing possibility over the distant horizon.

The role of LEPR, PPARG and PPARGC1A genes polymorphisms in the development of metabolic disorders in patients with vibration diseases

Introduction. Patients with vibration disease (VD) often have obesity and metabolic syndrome (MS), which increase the risk of developing type 2 diabetes, hypertension, and other conditions predisposing to a decrease in the quality and longevity of life. Genetic predisposition, overnutrition, environmental factors, including industrial ones, and others are factors influencing the formation of MS. The aim of the study is to identify associations between polymorphisms of the LEPR, PPARG and PPARGC1A genes, metabolic syndrome and obesity in VD patients caused by exposure to local vibration and the combined effects of local and general vibration. Material and methods. We examined 248 VD male patients exposed to local vibration and the combined impact of the local and general vibration. We have identified a subgroup of MS and obesity cases. The distribution of genotypes of the LEPR, PPARG and PPARGC1A genes in groups was studied. Results. In the group of VD and MS patients exposed to the combined effect of local and general vibration, the Gln/Gln genotype of the Arg223Gln polymorphic locus of the LEPR gene was less common, and the Arg / Gln genotype in MS cases was detected more often than in patients without it. Among patients with VD caused by exposure to local vibration with a waist circumference of more than 102 cm, the Gly / Ser genotype of the Gly482Ser polymorphism of the PPARGC1A gene was more common than among those with lower values of this indicator. Conclusion. In patients with VD caused by combined exposure to local and general vibration, the Gln/Gln genotype carrier of the Arg223Gln polymorphism of the LEPR gene may play a protective role in the formation of MS. Among individuals with VD caused by exposure to local vibration, carriers of the heterozygous genotype of the Gly482Ser polymorphism of the PPARGC1A gene may have a predisposition to the development of obesity. The obtained results are preliminary and require further research.

Genetic Biomarkers in Association with Depressive Disorder in UAE Residents: A Pilot Case Study

ObjectivesWe sought to explore the expression of genes associated with depressive disorder in patients with depression compared to control patients. A large body of research in the area of genetics has shown familial aggregation for depressive disorders. The purpose of this study was to identify genetic risk factors in developing depression, particularly among the population residing in the UAE.MethodsWe investigated five associated genes (PPARGC1A, CAMKMT, HSD11B1, SLC6A4, and MAOA) previously linked to depression and anxiety in other populations. The study was carried out in Al Ain, although participants were from different nationalities. Blood samples were collected over a period of seven months, and lab work was carried out over a period of two months from September 1, 2018 to May 30, 2019. We screened the prevalence of the PPARGC1A, CAMKMT, HSD11B1, SLC6A4, and MAOA in 29 patients with depressive disorder and 30 controls using the quantitative real-time polymerase chain reaction method.ResultsThe expression of the PPARGC1A gene, studied for the first time in the UAE population. The independent t-test was used to check the significance of difference between the expression levels of target genes where the control was set at a reference level of 1.0. PPARGC1A gene is lower among the depressed group which showed mean difference: 0.4 and p-value: 0.02, indicating a strong association with depression. No significant difference was found in the genes’ expression of CAMKMT with p-value 0.150, MAOA p-value 0.070, SLC6A4 p-value 0.750, and HSD11B1 p-value 0.100 in two groups in comparison with (p < 0.050).ConclusionsThese results open several possibilities for further research to study the role of this gene as a protective factor against developing depression.

Gynostemma pentaphyllum extract and Gypenoside L enhance skeletal muscle differentiation and mitochondrial metabolism by activating the PGC-1α pathway in C2C12 myotubes.

BACKGROUND/OBJECTIVESPeroxisome proliferator-activated receptor-gamma co-activator-1α (PGC-1α) has a central role in regulating muscle differentiation and mitochondrial metabolism. PGC-1α stimulates muscle growth and muscle fiber remodeling, concomitantly regulating lactate and lipid metabolism and promoting oxidative metabolism. Gynostemma pentaphyllum (Thumb.) has been widely employed as a traditional herbal medicine and possesses antioxidant, anti-obesity, anti-inflammatory, hypolipemic, hypoglycemic, and anticancer properties. We investigated whether G. pentaphyllum extract (GPE) and its active compound, gypenoside L (GL), affect muscle differentiation and mitochondrial metabolism via activation of the PGC-1α pathway in murine C2C12 myoblast cells.MATERIALS/METHODSC2C12 cells were treated with GPE and GL, and quantitative reverse transcription polymerase chain reaction and western blot were used to analyze the mRNA and protein expression levels. Myh1 was determined using immunocytochemistry. Mitochondrial reactive oxygen species generation was measured using the 2′7′-dichlorofluorescein diacetate assay.RESULTSGPE and GL promoted the differentiation of myoblasts into myotubes and elevated mRNA and protein expression levels of Myh1 (type IIx). GPE and GL also significantly increased the mRNA expression levels of the PGC-1α gene (Ppargc1a), lactate metabolism-regulatory genes (Esrra and Mct1), adipocyte-browning gene fibronectin type III domain-containing 5 gene (Fndc5), glycogen synthase gene (Gys), and lipid metabolism gene carnitine palmitoyltransferase 1b gene (Cpt1b). Moreover, GPE and GL induced the phosphorylation of AMP-activated protein kinase, p38, sirtuin1, and deacetylated PGC-1α. We also observed that treatment with GPE and GL significantly stimulated the expression of genes associated with the anti-oxidative stress response, such as Ucp2, Ucp3, Nrf2, and Sod2.CONCLUSIONSThe results indicated that GPE and GL enhance exercise performance by promoting myotube differentiation and mitochondrial metabolism through the upregulation of PGC-1α in C2C12 skeletal muscle.

Genotyping and Whole-Genome Resequencing of Welsh Sheep Breeds Reveal Candidate Genes and Variants for Adaptation to Local Environment and Socioeconomic Traits.

BackgroundAdvances in genetic tools applied to livestock breeding has prompted research into the previously neglected breeds adapted to harsh local environments. One such group is the Welsh mountain sheep breeds, which can be farmed at altitudes of 300 m above sea level but are considered to have a low productive value because of their poor wool quality and small carcass size. This is contrary to the lowland breeds which are more suited to wool and meat production qualities, but do not fare well on upland pasture. Herein, medium-density genotyping data from 317 individuals representing 15 Welsh sheep breeds were used alongside the whole-genome resequencing data of 14 breeds from the same set to scan for the signatures of selection and candidate genetic variants using haplotype- and SNP-based approaches.ResultsHaplotype-based selection scan performed on the genotyping data pointed to a strong selection in the regions of GBA3, PPARGC1A, APOB, and PPP1R16B genes in the upland breeds, and RNF24, PANK2, and MUC15 in the lowland breeds. SNP-based selection scan performed on the resequencing data pointed to the missense mutations under putative selection relating to a local adaptation in the upland breeds with functions such as angiogenesis (VASH1), anti-oxidation (RWDD1), cell stress (HSPA5), membrane transport (ABCA13 and SLC22A7), and insulin signaling (PTPN1 and GIGFY1). By contrast, genes containing candidate missense mutations in the lowland breeds are related to cell cycle (CDK5RAP2), cell adhesion (CDHR3), and coat color (MC1R).ConclusionWe found new variants in genes with potentially functional consequences to the adaptation of local sheep to their environments in Wales. Knowledge of these variations is important for improving the adaptative qualities of UK and world sheep breeds through a marker-assisted selection.

Cardiac Fibroblast-Specific Knockout of PGC-1α Accelerates AngII-Induced Cardiac Remodeling.

Cardiac remodeling consisted of ventricular hypertrophy and interstitial fibrosis is the pathological process of many heart diseases. Fibroblasts as one of the major cells in the myocardium regulate the balance of the generation and degeneration of collagen, and these cells transform toward myofibroblasts in pathological state, contributing to the remodeling of the heart. Peroxisome proliferator-activated receptor-γ (PPAR-γ) coactivator-1α (PGC-1α) is vital to the function of mitochondria, which contributes to the energy production and reactive oxidative species (ROS)-scavenging activity in the heart. In this study, we found that fibroblast-specific PGC-1α KO induced cardiac remodeling especially fibrosis, and Angiotensin II (AngII) aggravated cardiac fibrosis, accompanied with a high level of oxidative stress response and inflammation.

Pioglitazone Inhibits Diabetes-Induced Atrial Mitochondrial Oxidative Stress and Improves Mitochondrial Biogenesis, Dynamics, and Function Through the PPAR-γ/PGC-1α Signaling Pathway.

Background: Oxidative stress contributes to adverse atrial remodeling in diabetes mellitus. This remodeling can be prevented by the PPAR-γ agonist pioglitazone via its antioxidant and anti-inflammatory effects. In this study, we examined the molecular mechanisms underlying the protective effects of pioglitazone on atrial remodeling in a rabbit model of diabetes. Methods: Rabbits were randomly divided into control, diabetic, and pioglitazone-treated diabetic groups. Echocardiographic, hemodynamic, and electrophysiological parameters were measured. Serum PPAR-γ levels, serum and tissue oxidative stress and inflammatory markers, mitochondrial morphology, reactive oxygen species (ROS) production rate, respiratory function, and mitochondrial membrane potential (MMP) levels were measured. Protein expression of the pro-fibrotic marker TGF-β1, the PPAR-γ coactivator-1α (PGC-1α), and the mitochondrial proteins (biogenesis-, fusion-, and fission-related proteins) was measured. HL-1 cells were transfected with PGC-1α small interfering RNA (siRNA) to determine the underlying mechanisms of pioglitazone improvement of mitochondrial function under oxidative stress. Results: The diabetic group demonstrated a larger left atrial diameter and fibrosis area than the controls, which were associated with a higher incidence of inducible atrial fibrillation (AF). The lower serum PPAR-γ level was associated with lower PGC-1α and higher NF-κB and TGF-β1 expression. Lower mitochondrial biogenesis (PGC-1α, NRF1, and TFAM)-, fusion (Opa1 and Mfn1)-, and fission (Drp1)-related proteins were detected. Mitochondrial swelling, higher mitochondrial ROS, lower respiratory control rate, and lower MMP were observed. The pioglitazone group showed a reversal of structural remodeling and a lower incidence of inducible AF, which were associated with higher PPAR-γ and PGC-1α. The pioglitazone group had lower NF-κB and TGF-β1 expression levels, whereas biogenesis-, fusion-, and fission-related protein expression was higher. Further, mitochondrial structure and function were improved. In HL-1 cells, PGC-1α siRNA transfection blunted the effect of pioglitazone on Mn-SOD protein expression and MMP collapse in H2O2-treated cells. Conclusion: Diabetes mellitus induces adverse atrial structural, electrophysiological remodeling, and mitochondrial damage and dysfunction. Pioglitazone prevented these abnormalities through the PPAR-γ/PGC-1α pathway.

The sympathetic/beta-adrenergic pathway mediates irisin regulation of cardiac functions in zebrafish

Irisin is a 23 kDa myokine encoded in its precursor, fibronectin type III domain containing 5 (FNDC5). The exercise-induced increase in the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α) promotes FNDC5 mRNA, followed by the proteolytic cleavage of FNDC5 to release irisin from the skeletal or cardiac muscle into the blood. Irisin is abundantly expressed in skeletal and cardiac muscle and plays an important role in feeding, modulates appetite regulatory peptides, and regulates cardiovascular functions in zebrafish. In order to determine the potential mechanisms of acute irisin effects, in this research, we explored whether adrenergic or muscarinic pathways mediate the cardiovascular effects of irisin. Propranolol (100 ng/g B·W) alone modulated cardiac functions, and when injected in combination with irisin (0.1 ng/g B·W) attenuated the effects of irisin in regulating cardiovascular functions in zebrafish at 15 min post-injection. Atropine (100 ng/g B·W) modulated cardiovascular physiology in the absence of irisin, while it was ineffective in influencing irisin-induced effects on cardiovascular functions in zebrafish. At 1 h post-injection, irisin downregulated PGC-1 alpha mRNA, myostatin-a and myostatin-b mRNA expression in zebrafish heart and skeletal muscle. Propranolol alone had no effect on the expression of these mRNAs in zebrafish and did not alter the irisin-induced changes in expression. At 1 h post-injection, irisin siRNA downregulated PGC-1 alpha, troponin C and troponin T2D mRNA expression, while upregulating myostatin a and b mRNA expression in zebrafish heart and skeletal muscle. Atropine alone had no effects on mRNA expression, and was unable to alter effects on mRNA expression of siRNA. Overall, this research identified a role for the sympathetic/beta-adrenergic pathway in regulating irisin effects on cardiovascular physiology and cardiac gene expression in zebrafish.

PGC-1α deficiency reveals sex-specific links between cardiac energy metabolism and EC-coupling during development of heart failure in mice.

AimsBiological sex has fundamental effects on mammalian heart physiology and pathogenesis. While it has been established that female sex is a protective factor against most cardiovascular diseases (CVDs), this beneficial effect may involve pathways associated with cardiac energy metabolism. Our aim was to elucidate the role of transcriptional coactivator PGC-1α in sex dimorphism of heart failure (HF) development.Methods and resultsHere, we show that mice deficient in cardiac expression of the peroxisome proliferator-activated receptor gamma (PPAR-γ) coactivator-1α (PGC-1α) develop dilated HF associated with changes in aerobic and anaerobic metabolism, calcium handling, cell structure, electrophysiology, as well as gene expression. These cardiac changes occur in both sexes, but female mice develop an earlier and more severe structural and functional phenotype associated with dyssynchronous local calcium release resulting from disruption of t-tubular structures of the cardiomyocytes.ConclusionsThese data reveal that the integrity of the subcellular Ca2+ release and uptake machinery is dependent on energy metabolism and that female hearts are more prone to suffer from contractile dysfunction in conditions with compromised production of cellular energy. Furthermore, these findings suggest that PGC-1α is a central mediator of sex-specific differences in heart function and CVD susceptibility.

1168-P: Serum MicroRNA-122 and -192 Are Increased in Adolescents with NAFLD: Potential Role as Biomarkers

The best available blood biomarker for nonalcoholic fatty liver disease (NAFLD) is alanine aminotransferase (ALT), though it does not reliably distinguish NAFLD severity. Alternate biomarkers have been tested in adults, but fewer in children. We tested serum microRNA-122 (miR-122) as a biomarker for NAFLD in adolescents since it inhibts hepatic lipogenesis in animals and is exported from liver to blood with disease progression. The only prior study of miR-122 in children produced mixed results. We also measured miR-192, -130b, and -155 as they have roles in hepatic lipogenesis. Participants were boys and girls, 12-20 y, with biopsy-confirmed NAFLD (n=23), and peers without NAFLD who were either obese (Ob, n=22), or normal weight (NW, n=24). RNA was extracted from serum from all participants and from liver biopsies from the NAFLD group. Serum miR-122 and -192 were 12- and 10-fold higher (p&amp;lt; 0.01), respectively, in NAFLD patients compared to both Ob and NW controls. Within the NAFLD group, serum abundances of miR-122 and -192 were inversely correlated with their liver values (r = -0.51, p = 0.002 and r = -0.40, p = 0.067, respectively), and positively correlated with histological scores for steatosis (r = 0.39 and 0.28, respectively) and fibrosis (r = 0.56 and 0.54, respectively). mIR-122 and -192 content were also positively correlated with ALT (r = 0.78 for both) and with each other in both serum (r = 0.92) and liver (r = 0.74), suggesting similar regulation. Areas under the receiver operating curve for distinguishing NAFLD was 0.95 for miR-122 and -192. Serum miR-130b, which regulates PGC-1 alpha, was 2.6-fold higher in serum from NAFLD patients versus both control groups, while serum miR-155, which regulates lipogenesis and inflammation, did not differ in NAFLD. Serum miR-130b and miR-155 values were not correlated with their corresponding values in liver biopsies. These results support the potential use of miR-122 and -192 as biomarkers for the presence and severity of NAFLD in adolescents. Disclosure K. R. Short: None. S. Palle: None. D. S. Amaya hellman: None. S. Jiang: None. J. B. Tryggestad: None. E. Fematt garcia: None. Funding Oklahoma Shared Clinical &amp; Translational Resource

Features of genes copy number in normal, primary tumor, and lymph nodes metastases cells in patients with cervical cancer.

e17503 Background: Early stages of cervical cancer (CC) can be treated with surgery or radiation therapy, metastatic CC is incurable, and therefore new diagnostic approaches based on highly effective molecular markers are required. As such markers, the Copy Number Variation (CNV) is of great interest. Purpose of the study: to analyze the peculiarities of genes CNV in normal cells, primary tumor and lymph nodes tumor metastases cells in patients with CC. Methods: Tissue sections from FFPE-blocks of 300 patients with CC were used for the study. Primary tumor, tumor metastatic and normal cells were isolated using non-contact laser microdissection (Palm MicroBeam, Carl Zeiss). DNA was extracted from the cells using the phenol-chloroform method. Determination of 14 genes CNV (LAMP3, PRKAA1, TORC2, FOXO3, HDAC5, MEF2C, MLXIPL, EP300, HNF4A, TP53, SREBF1, SREBF2, PPARGC1A, and CCND1) was performed by Real-Time qPCR method. Statistical analysis was performed using the Mann-Whitney test; Bonferroni's correction was applied to correct multiple comparisons. Results: An increase in the CNV of LAMP3 and TORC2 genes by 2.5 and 3.2 times (p &lt; 0.05), respectively, and a decrease in the CNV of TP53 and FOXO3 genes by 2.3 and 2.0 times (p &lt; 0.05), respectively, were found in the primary tumor cells relative to normal cells. The effect of the simultaneous change in the CNV of LAMP3, TORC2, TP53 and FOXO3 genes was observed in 60% of the sample, and LAMP3 and TP53 genes - in 80%. In cells of lymph nodes tumor metastases an increase in the CNV of CCND1 and TORC2 genes by 2.0 and 3.5 times (p &lt; 0.05), respectively, was found, as well as a decrease in the CNV of PPARGC1A gene by 2.1 times (p &lt; 0.05) relative to normal cells. A simultaneous change in the CNV of CCND1, TORC2, and PPARGC1A was observed in 70% of the sample, and CNV of CCND1 and TORC2 genes - in 85%. Primary tumor and metastases cells differed in the CNV of CCND1 (2.5 times higher in metastatic cells), LAMP3 (3.0 times lower in metastatic cells) and FOXO3 genes (2.0 times higher in metastatic cells). Conclusions: Thus, the primary tumor and lymph nodes metastases cells differ in the level of genes CNV from normal cervix cells. Accordingly, the CNV of LAMP3, TORC2, TP53 and FOXO3 genes may have the potential for diagnosing a primary cervical tumor, and the CNV of CCND1, TORC2 and PPARGC1A genes for diagnosing its metastases to regional lymph nodes.