Long non-coding RNA Tug1 modulates mitochondrial and myogenic responses to exercise in skeletal muscle.

BACKGROUND: Mitochondria have an essential role in regulating metabolism and integrate environmental and physiological signals to affect processes such as cellular bioenergetics and response to stress. In the metabolically active skeletal muscle, mitochondrial biogenesis is one important component contributing to a broad set of mitochondrial adaptations occurring in response to signals, which converge on the biogenesis transcriptional regulator peroxisome proliferator-activated receptor coactivator 1-alpha (PGC-1α), and is central to the beneficial effects of exercise in skeletal muscle. We investigated the role of long non-coding RNA (lncRNA) taurine-upregulated gene 1 (TUG1), which interacts with PGC-1α in regulating transcriptional responses to exercise in skeletal muscle. RESULTS: In human skeletal muscle, TUG1 gene expression was upregulated post-exercise and was also positively correlated with the increase in PGC-1α gene expression (PPARGC1A). Tug1 knockdown (KD) in differentiating mouse myotubes led to decreased Ppargc1a gene expression, impaired mitochondrial respiration and morphology, and enhanced myosin heavy chain slow isoform protein expression. In response to a Ca2+-mediated stimulus, Tug1 KD prevented an increase in Ppargc1a expression. RNA sequencing revealed that Tug1 KD impacted mitochondrial Ca2+ transport genes and several downstream PGC-1α targets. Finally, Tug1 KD modulated the expression of ~300 genes that were upregulated in response to an in vitro model of exercise in myotubes, including genes involved in regulating myogenesis. CONCLUSIONS: We found that TUG1 is upregulated in human skeletal muscle after a single session of exercise, and mechanistically, Tug1 regulates transcriptional networks associated with mitochondrial calcium handling, muscle differentiation and myogenesis. These data demonstrate that lncRNA Tug1 exerts regulation over fundamental aspects of skeletal muscle biology and response to exercise stimuli.

Medical and Surgical Treatment of Reproductive Outcomes in Polycystic Ovary Syndrome: An Overview of Systematic Reviews.

Polycystic ovary syndrome (PCOS) is a common, complex condition that affects up to 18% of reproductiveaged women, causing reproductive, metabolic and psychological dysfunctions. We performed an overview and appraisal of methodological quality of systematic reviews that assessed medical and surgical treatments for reproductive outcomes in women with PCOS. Databases (MEDLINE, EMBASE, CINAHL PLUS and PROSPERO) were searched on the 15th of September 2017. We included any systematic review that assessed the effect of medical or surgical management of PCOS on reproductive, pregnancy and neonatal outcomes. Eligibility assessment, data extraction and quality assessment by the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool were performed in duplicate. We identified 53 reviews comprising 44 reviews included in this overview; the majority were moderate to high quality. In unselected women with PCOS, letrozole was associated with a higher live birth rate than clomiphene citrate (CC), while CC was better than metformin or placebo. In women with CC-resistant PCOS, gonadotrophins were associated with a higher live birth rate than CC plus metformin, which was better than laparoscopic ovarian drilling (LOD). LOD was associated with lower multiple pregnancy rates than other medical treatments. In women with PCOS undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), the addition of metformin to gonadotrophins resulted in less ovarian hyperstimulation syndrome (OHSS), and higher pregnancy and live birth rates than gonadotrophins alone. Gonadotrophin releasing hormone (GnRH) antagonist was associated with less OHSS, gonadotrophin units and shorter stimulation length than GnRH agonist. Letrozole appears to be a good first line treatment and gonadotrophins, as a second line treatment, for anovulatory women with PCOS. LOD results in lower multiple pregnancy rates. However, due to the heterogeneous nature of the included populations of women with PCOS, further larger scale trials are needed with more precise assessment of treatments according to heterogeneous variants of PCOS.

Acute HIIE elicits similar changes in human skeletal muscle mitochondrial H2O2 release, respiration, and cell signaling as endurance exercise even with less work.

It remains unclear whether high-intensity interval exercise (HIIE) elicits distinct molecular responses to traditional endurance exercise relative to the total work performed. We aimed to investigate the influence of exercise intensity on acute perturbations to skeletal muscle mitochondrial function (respiration and reactive oxygen species) and metabolic and redox signaling responses. In a randomized, repeated measures crossover design, eight recreationally active individuals (24 ± 5 yr; V̇o2peak: 48 ± 11 ml·kg-1·min-1) undertook continuous moderate-intensity [CMIE: 30 min, 50% peak power output (PPO)], high-intensity interval (HIIE: 5 × 4 min, 75% PPO, work matched to CMIE), and low-volume sprint interval (SIE: 4 × 30 s) exercise, ≥7 days apart. Each session included muscle biopsies at baseline, immediately, and 3 h postexercise for high-resolution mitochondrial respirometry ( Jo2) and H2O2 emission ( Jh2o2) and gene and protein expression analysis. Immediately postexercise and irrespective of protocol, Jo2 increased during complex I + II leak/state 4 respiration but Jh2o2 decreased ( P < 0.05). AMP-activated protein kinase and acetyl co-A carboxylase phosphorylation increased ~1.5 and 2.5-fold respectively, while thioredoxin-reductase-1 protein abundance was ~35% lower after CMIE vs. SIE ( P < 0.05). At 3 h postexercise, regardless of protocol, Jo2 was lower during both ADP-stimulated state 3 OXPHOS and uncoupled respiration ( P < 0.05) but Jh2o2 trended higher ( P < 0.08) and PPARGC1A mRNA increased ~13-fold, and peroxiredoxin-1 protein decreased ~35%. In conclusion, intermittent exercise performed at high intensities has similar dynamic effects on muscle mitochondrial function compared with endurance exercise, irrespective of whether total workload is matched. This suggests exercise prescription can accommodate individual preferences while generating comparable molecular signals known to promote beneficial metabolic adaptations.

Comorbidities and complications of polycystic ovary syndrome: An overview of systematic reviews.

BACKGROUND: Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies affecting reproductive-aged women with adverse reproductive, metabolic and psychological outcomes. It has a complex pathophysiology and therefore requires a multidiscipline clinical approach. However, there remains limited research synthesizing the broad clinical implications of PCOS which would assist clinicians in the management of PCOS. OBJECTIVE: To summarize and appraise methodological quality of systematic reviews and meta-analyses evaluating complications and comorbidities associated with PCOS. METHODS: A literature search from MEDLINE, EMBASE, CINAHL PLUS and PROSPERO was performed until 15 September 2017. Article selection, data extraction and quality appraisal of included reviews using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool were performed in duplicate. A narrative synthesis of the findings was conducted. RESULTS: Twenty-three reviews were included. All reviews were of low (n = 2) to moderate quality (n = 21). PCOS was associated with adverse pregnancy outcomes (n = 2), impaired glucose tolerance (n = 6), insulin resistance (n = 6), increased risk of type 2 diabetes (n = 1), cardiovascular disease (n = 10), metabolic syndrome (n = 2), psychological stress (n = 7), endometrial cancer (n = 1) and vitamin D deficiency (n = 1). Obesity exacerbates many of these outcomes. CONCLUSIONS: There is a large body of reliable evidence for adverse metabolic outcomes and smaller, but consistent evidence for psychological issues in PCOS. We identified a shortage of systematic reviews regarding pregnancy outcomes of PCOS and significant gaps in knowledge of the association between PCOS and subclinical hyperthyroidism, vitamin D levels and cancers which future studies could aim to address.

Pharmacological and surgical treatment of nonreproductive outcomes in polycystic ovary syndrome: An overview of systematic reviews.

BACKGROUND: Polycystic ovary syndrome (PCOS) affects up to 13% women and is associated with significant complications. The quality of evidence supporting the recommendations on treatment of nonreproductive outcomes in PCOS is unknown. OBJECTIVE: To summarize and appraise the methodological quality of systematic reviews and meta-analyses evaluating pharmacological and surgical treatments for nonreproductive outcomes in PCOS. METHODS: A literature search from MEDLINE, EMBASE, CINAHL PLUS and PROSPERO was performed from inception until 15th of September 2017. Article selection, data extraction and quality appraisal of included reviews were performed in duplicate. A narrative synthesis of the findings was conducted. RESULTS: This overview included 31 reviews. The quality was low for 7 (23%), moderate for sixteen (52%) and high for 8 reviews (26%). Two reviews assessed psychological outcomes. Metformin improved anthropometric (7 of 10 reviews), metabolic (4 of 14 reviews) and endocrine outcomes (3 of twelve reviews). Thiazolidinediones improved metabolic (2 of 5 reviews) and endocrine outcomes (one of 5 reviews) but worsened weight gain (5 of 5 reviews). Combined oral contraceptive pill (COCP) improved clinical hyperandrogenism (2 of 2 reviews). Statins improved lipid profile (3 of 3 reviews) and testosterone level (2 of 3 reviews). There was no conclusive evidence from included systematic reviews regarding the use of other interventions. CONCLUSIONS: There is reliable evidence regarding the use of metformin for anthropometric outcomes and COCPs for hyperandrogenism in women with PCOS but not for other interventions. There is significant gap in knowledge regarding the management of psychological outcomes in women with PCOS which needs further evaluation.

High-molecular-weight adiponectin is inversely associated with sympathetic activity in polycystic ovary syndrome.

OBJECTIVE: To examine the role of high-molecular-weight (HMW) adiponectin and its relationship to sympathetic activity in women with polycystic ovary syndrome (PCOS). DESIGN: Cross sectional study using biobanked samples. SETTING: Not applicable. PATIENT(S): Premenopausal women with PCOS (n = 46, Rotterdam diagnostic criteria) and without PCOS (n = 22). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): High-molecular-weight adiponectin levels with secondary outcomes of sympathetic activity and leptin levels. RESULT(S): The high-molecular-weight adiponectin level was lower in women with PCOS (median 2.2 [interquartile range (IQR)2.3] µg/mL) than in controls (median 3 [IQR2.5] µg/mL) (age and BMI adjusted), and it correlated inversely with the values measured for homeostatic model of assessment of insulin resistance (HOMA-IR), fasting insulin, triglycerides, and free androgen index and positively with sex hormone-binding globulin (SHBG) and high-density lipoprotein cholesterol in all participants and in the PCOS group. In the PCOS group, sympathetic activity (burst frequency) was statistically significantly higher than in controls (median 26 [IQR11] vs. median 22 [IQR14], respectively) and correlated inversely with HMW adiponectin (r = -0.230). The leptin levels were similar between the women with PCOS and controls and did not statistically significantly correlate with HMW adiponectin or sympathetic activity. On multiple regression analysis, burst frequency and SHBG explained 40% of the HMW adiponectin variability (B = -0.7; 95% CI -1.2 to -0.2; and B = 0.01; 95% CI 0.004-0.01) in PCOS. CONCLUSION(S): Alongside insulin resistance, increased sympathetic activity is associated with and may modulate HMW adiponectin levels in women with PCOS.