TGF-β Induction of miR-143/145 Is Associated to Exercise Response by Influencing Differentiation and Insulin Signaling Molecules in Human Skeletal Muscle

Physical training improves insulin sensitivity and can prevent type 2 diabetes (T2D). However, approximately 20% of individuals lack a beneficial outcome in glycemic control. TGF-β, identified as a possible upstream regulator involved in this low response, is also a potent regulator of microRNAs (miRNAs). The aim of this study was to elucidate the potential impact of TGF-β-driven miRNAs on individual exercise response. Non-targeted long and sncRNA sequencing analyses of TGF-β1-treated human skeletal muscle cells corroborated the effects of TGF-β1 on muscle cell differentiation, the induction of extracellular matrix components, and identified several TGF-β1-regulated miRNAs. qPCR validated a potent upregulation of miR-143-3p/145-5p and miR-181a2-5p by TGF-β1 in both human myoblasts and differentiated myotubes. Healthy subjects who were overweight or obese participated in a supervised 8-week endurance training intervention (n = 40) and were categorized as responder or low responder in glycemic control based on fold change ISIMats (≥+1.1 or <+1.1, respectively). In skeletal muscle biopsies of low responders, TGF-β signaling and miR-143/145 cluster levels were induced by training at much higher rates than among responders. Target-mining revealed HDACs, MYHs, and insulin signaling components INSR and IRS1 as potential miR-143/145 cluster targets. All these targets were down-regulated in TGF-β1-treated myotubes. Transfection of miR-143-3p/145-5p mimics in differentiated myotubes validated MYH1, MYH4, and IRS1 as miR-143/145 cluster targets. Elevated TGF-β signaling and miR-143/145 cluster induction in skeletal muscle of low responders might obstruct improvements in insulin sensitivity by training in two ways: by a negative impact of miR-143-3p on muscle cell fusion and myofiber functionality and by directly impairing insulin signaling via a reduction in INSR by TGF-β and finetuned IRS1 suppression by miR-143-3p.

Download Full-text

Effects of a Botanical Extract from Artemisia dracunculus L. on Insulin Sensitivity of Human Skeletal Muscle Cell Cultures

Planta Medica ◽

10.1055/s-0031-1273665 ◽

2011 ◽

Vol 77 (05) ◽

Author(s):

P Scherp ◽

N Putluri ◽

GJ LeBlanc ◽

WT Cefalu ◽

I Kheterpal

Keyword(s):

Skeletal Muscle ◽

Insulin Sensitivity ◽

Muscle Cell ◽

Cell Cultures ◽

Human Skeletal Muscle ◽

Skeletal Muscle Cell ◽

Artemisia Dracunculus ◽

Human Skeletal Muscle Cell ◽

Botanical Extract

Download Full-text

Insulin signaling and insulin sensitivity after exercise in human skeletal muscle

Diabetes ◽

10.2337/diabetes.49.3.325 ◽

2000 ◽

Vol 49 (3) ◽

pp. 325-331 ◽

Cited By ~ 236

Author(s):

J. Wojtaszewski ◽

B. Hansen ◽

J Gade ◽

B Kiens ◽

J. Markuns ◽

...

Keyword(s):

Skeletal Muscle ◽

Insulin Sensitivity ◽

Insulin Signaling ◽

Human Skeletal Muscle

Download Full-text

Zinc stimulates glucose oxidation and glycemic control by modulating the insulin signaling pathway in human and mouse skeletal muscle cell lines

PLoS ONE ◽

10.1371/journal.pone.0191727 ◽

2018 ◽

Vol 13 (1) ◽

pp. e0191727 ◽

Cited By ~ 16

Author(s):

Shaghayegh Norouzi ◽

John Adulcikas ◽

Sukhwinder Singh Sohal ◽

Stephen Myers

Keyword(s):

Skeletal Muscle ◽

Glycemic Control ◽

Signaling Pathway ◽

Cell Lines ◽

Muscle Cell ◽

Insulin Signaling ◽

Glucose Oxidation ◽

Skeletal Muscle Cell ◽

Mouse Skeletal Muscle ◽

Human And Mouse

Download Full-text

Does impaired mitochondrial function affect insulin signaling and action in cultured human skeletal muscle cells?

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00267.2007 ◽

2008 ◽

Vol 294 (1) ◽

pp. E97-E102 ◽

Cited By ~ 8

Author(s):

Audrey E. Brown ◽

Matthias Elstner ◽

Stephen J. Yeaman ◽

Douglass M. Turnbull ◽

Mark Walker

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Insulin Signaling ◽

Mitochondrial Respiration ◽

Respiratory Function ◽

Insulin Action ◽

Human Skeletal Muscle ◽

Human Skeletal Muscle Cells ◽

Basal Glucose Uptake

Insulin-resistant type 2 diabetic patients have been reported to have impaired skeletal muscle mitochondrial respiratory function. A key question is whether decreased mitochondrial respiration contributes directly to the decreased insulin action. To address this, a model of impaired cellular respiratory function was established by incubating human skeletal muscle cell cultures with the mitochondrial inhibitor sodium azide and examining the effects on insulin action. Incubation of human skeletal muscle cells with 50 and 75 μM azide resulted in 48 ± 3% and 56 ± 1% decreases, respectively, in respiration compared with untreated cells mimicking the level of impairment seen in type 2 diabetes. Under conditions of decreased respiratory chain function, insulin-independent (basal) glucose uptake was significantly increased. Basal glucose uptake was 325 ± 39 pmol/min/mg (mean ± SE) in untreated cells. This increased to 669 ± 69 and 823 ± 83 pmol/min/mg in cells treated with 50 and 75 μM azide, respectively (vs. untreated, both P < 0.0001). Azide treatment was also accompanied by an increase in basal glycogen synthesis and phosphorylation of AMP-activated protein kinase. However, there was no decrease in glucose uptake following insulin exposure, and insulin-stimulated phosphorylation of Akt was normal under these conditions. GLUT1 mRNA expression remained unchanged, whereas GLUT4 mRNA expression increased following azide treatment. In conclusion, under conditions of impaired mitochondrial respiration there was no evidence of impaired insulin signaling or glucose uptake following insulin exposure in this model system.

Download Full-text

Overexpression of Long-Chain Acyl-CoA Synthetase 5 Increases Fatty Acid Oxidation and Free Radical Formation While Attenuating Insulin Signaling in Primary Human Skeletal Myotubes

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16071157 ◽

2019 ◽

Vol 16 (7) ◽

pp. 1157 ◽

Cited By ~ 3

Author(s):

Hyo-Bum Kwak ◽

Tracey Woodlief ◽

Thomas Green ◽

Julie Cox ◽

Robert Hickner ◽

...

Keyword(s):

Skeletal Muscle ◽

Fatty Acid ◽

Free Radical ◽

Fatty Acid Oxidation ◽

Insulin Signaling ◽

Human Skeletal Muscle ◽

Acid Oxidation ◽

Protein Levels ◽

Human Skeletal Muscle Cells ◽

Mitochondrial Fatty Acid

In rodent skeletal muscle, acyl-coenzyme A (CoA) synthetase 5 (ACSL-5) is suggested to localize to the mitochondria but its precise function in human skeletal muscle is unknown. The purpose of these studies was to define the role of ACSL-5 in mitochondrial fatty acid metabolism and the potential effects on insulin action in human skeletal muscle cells (HSKMC). Primary myoblasts isolated from vastus lateralis (obese women (body mass index (BMI) = 34.7 ± 3.1 kg/m2)) were transfected with ACSL-5 plasmid DNA or green fluorescent protein (GFP) vector (control), differentiated into myotubes, and harvested (7 days). HSKMC were assayed for complete and incomplete fatty acid oxidation ([1-14C] palmitate) or permeabilized to determine mitochondrial respiratory capacity (basal (non-ADP stimulated state 4), maximal uncoupled (carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP)-linked) respiration, and free radical (superoxide) emitting potential). Protein levels of ACSL-5 were 2-fold higher in ACSL-5 overexpressed HSKMC. Both complete and incomplete fatty acid oxidation increased by 2-fold (p < 0.05). In permeabilized HSKMC, ACSL-5 overexpression significantly increased basal and maximal uncoupled respiration (p < 0.05). Unexpectedly, however, elevated ACSL-5 expression increased mitochondrial superoxide production (+30%), which was associated with a significant reduction (p < 0.05) in insulin-stimulated p-Akt and p-AS160 protein levels. We concluded that ACSL-5 in human skeletal muscle functions to increase mitochondrial fatty acid oxidation, but contrary to conventional wisdom, is associated with increased free radical production and reduced insulin signaling.

Download Full-text

CORTISOL CIRCADIAN RHYTHM AND INSULIN RESISTANCE IN MUSCLE: EFFECT OF DOSING AND TIMING OF HYDROCORTISONE EXPOSURE ON INSULIN SENSITIVITY IN SYNCHRONIZED MUSCLE CELLS.

Neuroendocrinology ◽

10.1159/000512685 ◽

2020 ◽

Author(s):

Mariarosaria Negri ◽

Claudia Pivonello ◽

Chiara Simeoli ◽

Gilda Di Gennaro ◽

Mary Anna Venneri ◽

...

Keyword(s):

Skeletal Muscle ◽

Circadian Rhythm ◽

Insulin Sensitivity ◽

Circadian Clock ◽

Insulin Signaling ◽

Clock Genes ◽

Muscle Cells ◽

C2c12 Cells ◽

Circadian Expression

Introduction/Aim: Circadian rhythm disruption is emerging as a risk factor for metabolic disorders and particularly, alterations in clock genes circadian expression have been shown to influence insulin sensitivity. Recently, the reciprocal interplay between the circadian clock machinery and HPA axis has been largely demonstrated: the circadian clock may control the physiological circadian endogenous glucocorticoids secretion and action; glucocorticoids, in turn, are potent regulator of the circadian clock and their inappropriate replacement has been associated with metabolic impairment. The aim of the current study was to investigate in vitro the interaction between the timing-of-the-day exposure to different hydrocortisone (HC) concentrations on muscle insulin sensitivity. Methods: Serum-shock synchronized mouse skeletal muscle C2C12 cells were exposed to different HC concentrations recapitulating the circulating daily physiological cortisol profile (standard cortisol profile), the circulating daily cortisol profile that reached in adrenal insufficient (AI) patients treated with once-daily MR-HC (flat cortisol profile) and treated with thrice-daily of conventional IR-HC (steep cortisol profile). The 24 hrs spontaneous oscillation of the clock genes in synchronized C2C12 cells was used to align the timing for in vitro HC exposure (Bmal1 acrophase, midphase and bathyphase) with the reference times of cortisol peaks in AI treated with IR-HC (8 am, 1 pm, 6 pm). A panel of 84 insulin sensitivity related genes and intracellular insulin signaling proteins were analyzed by RT-qPCR and western blot, respectively. Results: Only the steep profile, characterized by a higher HC exposure during Bmal1 bathyphase, produced significant downregulation in 21 insulin sensitivity-related genes. Among these, Insr, Irs1, Irs2, Pi3kca and Adipor2 were downregulated when compared the flat to the standard or steep profile. Reduced intracellular IRS1 Tyr608, AKT Ser473, AMPK Thr172 and ACC Ser79 phosphorylations were also observed. Conclusions: The current study demonstrated that is late-in-the-day cortisol exposure that modulates insulin sensitivity-related genes expression and intracellular insulin signaling in skeletal muscle cells.

Download Full-text

Changes in dietary sodium consumption modulate GLUT4 gene expression and early steps of insulin signaling

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00396.2003 ◽

2004 ◽

Vol 286 (4) ◽

pp. R779-R785 ◽

Cited By ~ 15

Author(s):

Maristela Mitiko Okamoto ◽

Dóris Hissako Sumida ◽

Carla Roberta Oliveira Carvalho ◽

Alessandra Martins Vargas ◽

Joel Cláudio Heimann ◽

...

Keyword(s):

Gene Expression ◽

Skeletal Muscle ◽

Adipose Tissue ◽

Insulin Sensitivity ◽

Insulin Receptor ◽

Tyrosine Phosphorylation ◽

Insulin Signaling ◽

Dietary Sodium ◽

Glut4 Translocation ◽

Glut4 Gene Expression

Previous studies have shown that chronic salt overload increases insulin sensitivity, while chronic salt restriction decreases it. In the present study we investigated the influence of dietary sodium on 1) GLUT4 gene expression, by Northern and Western blotting analysis; 2) in vivo GLUT4 protein translocation, by measuring the GLUT4 protein in plasma membrane and microsome, before and after insulin injection; and 3) insulin signaling, by analyzing basal and insulin-stimulated tyrosine phosphorylation of insulin receptor (IR)-β, insulin receptor substrate (IRS)-1, and IRS-2. Wistar rats were fed normal-sodium (NS-0.5%), low-sodium (LS-0.06%), or high-sodium diets (HS-3.12%) for 9 wk and were killed under pentobarbital anesthesia. Compared with NS rats, HS rats increased ( P < 0.05) the GLUT4 protein in adipose tissue and skeletal muscle, whereas GLUT4 mRNA was increased only in adipose tissue. GLUT4 expression was unchanged in LS rats compared with NS rats. The GLUT4 translocation in HS rats was higher ( P < 0.05) both in basal and insulin-stimulated conditions. On the other hand, LS rats did not increase the GLUT4 translocation after insulin stimulus. Compared with NS rats, LS rats showed reduced ( P < 0.01) basal and insulin-stimulated tyrosine phosphorylation of IRS-1 in skeletal muscle and IRS-2 in liver, whereas HS rats showed enhanced basal tyrosine phosphorylation of IRS-1 in skeletal muscle ( P < 0.05) and of IRS-2 in liver. In summary, increased insulin sensitivity in HS rats is related to increased GLUT4 gene expression, enhanced insulin signaling, and GLUT4 translocation, whereas decreased insulin sensitivity of LS rats does not involve changes in GLUT4 gene expression but is related to impaired insulin signaling.

Download Full-text