Appendicular lean mass is lower in late compared with early perimenopausal women: potential role of FSH

The role of the insulin-like growth factors I and II (IGF-I and IGF-II), previously known as the somatomedins, in general growth and development of various tissues has been known for many years. Thought of exclusively as endocrine factors produced by the liver, and under the control of growth hormone, the somatomedins were known as the intermediaries by which growth hormone exerted its cellular effects during tissue growth and maturation. Eventually it was discovered that virtually every tissue type is capable of autocrine production of the IGFs, and their involvement in skeletal muscle tissue repair and regeneration became apparent. Recent advances in technology have allowed the characterisation of many of the different growth factors believed to play a role in muscle regeneration, and experimental manipulations of cells in culture have provided insight into the effects of the various growth factors on the myoblast. This paper explores the potential role of the IGFs in skeletal muscle regeneration. A critical role of IGF-II in terminal differentiation of proliferating muscle precurser cells following injury is proposed. Key words: growth factors, myogenesis, skeletal muscle regeneration

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Abstract 14297: Potential Role of the Tumor Suppressor WWOX in Mediating Skeletal Muscle-Lung Vasculature Crosstalk in PH-HFpEF

Circulation ◽

10.1161/circ.142.suppl_3.14297 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Gunner Halliday ◽

Yang Bai ◽

Marta T Gomes ◽

Dmitry Goncharov ◽

Elena Goncharova ◽

...

Keyword(s):

Skeletal Muscle ◽

Tumor Suppressor ◽

Potential Role ◽

Pulmonary Vascular Remodeling ◽

Expression Levels ◽

Promote Cell Proliferation ◽

Pulmonary Arterial ◽

Arterial Smooth Muscle Cells ◽

Group 2

Introduction: Pulmonary hypertension due to left heart disease (PH-LHD; Group 2), particularly in the context of heart failure with preserved ejection fraction (HFpEF), is the most common cause of PH worldwide. At present, no specific effective therapy has been identified mainly due to the fact that major pathways involved in the regulation of PH-HFpEF are still not well understood. Results: We have recently reported on a role of skeletal muscle sirtuin-3 (SIRT3) in modulating PH-HFpEF. Using skeletal muscle-specific SIRT3 knockout mice ( Sirt3 skm-/- ), we showed that absence of SIRT3 in skeletal muscle drastically reduced the pulmonary vascular tree accompanied by vascular proliferative remodeling. Interestingly, we found that expression levels of the tumor suppressor WW domain-containing oxidoreductase (WWOX) were decreased in pulmonary arterial smooth muscle cells (PASMCs) obtained from Sirt3 skm-/- mice, while no changes in SIRT3 activation levels were detected. Reduced WWOX expression levels were also found in PASMCs isolated from SU5416/Obese ZSF1 (Ob-Su) rat model of PH-HFpEF, in which the levels of SIRT3 activation were found to be decreased in skeletal muscle, but not in the lungs and PASMCs. No changes of WWOX levels were observed in skeletal muscle of Ob-Su rats or in pulmonary artery endothelial cells (PAECs) treated with plasma obtained from Ob-Su rats. Conclusions: Since reduction of WWOX in PASMCs has been shown to promote cell proliferation, HIF1α stabilization and pulmonary arterial hypertension (PAH; Group 1), our data suggest a potential role of WWOX in mediating skeletal muscle SIRT3 deficiency-associated remote pulmonary vascular remodeling in PH-HFpEF.

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Erythrocyte Long Chain Omega 3 Fatty Acids Are Associated with Higher Lean Mass in Postmenopausal Women Newly Diagnosed with Breast Cancer (P05-024-19)

Current Developments in Nutrition ◽

10.1093/cdn/nzz030.p05-024-19 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Author(s):

Martha Belury ◽

Rachel Cole ◽

Rebecca Andridge ◽

Qing Xie ◽

Ashleigh Keiter ◽

...

Keyword(s):

Breast Cancer ◽

Skeletal Muscle ◽

Fatty Acids ◽

Body Composition ◽

Lean Mass ◽

Cardiometabolic Health ◽

Omega 3 ◽

Appendicular Lean Mass ◽

Muscle Health ◽

Long Chain

Abstract Objectives Cancer contributes to adverse changes in body composition that may increase risk of cardiometabolic diseases. Skeletal muscle is a main driver of cardiometabolic health. We hypothesize that higher intake of long chain omega-3 polyunsaturated fatty acids (LCn3PUFAs) is associated with muscle health. This study evaluates whether LCn3PUFA exposure assessed in diet and in blood is associated with markers of muscle health in women with breast cancer. Methods This is a cross-sectional analysis evaluating LCn3PUFA exposure and markers of muscle health in women (N = 150) prior to treatment for breast cancer. Exposure to LCn3PUFAs was assessed by a diet history questionnaire (DHQ), a question specifically about supplement usage and biomarker of LCn3PUFAs in red blood cells (RBC). Body composition were measured at the same visit using dual x-ray absorptiometry. Linear regression models were used to test for associations. Results 13% (N = 19) of women reported using fish oil supplements (e.g., Supplement Users) and had significantly higher levels of RBC LCn3PUFAs than Supplement Non-users. In Supplement Non-users, there was a positive association between reported dietary exposure by DHQ and RBC LCn3PUFA levels. The n3 index (e.g., sum of RBC EPA + DHA) and DHA (22:6n3) were positively associated with appendicular lean mass/BMI. There were no significant correlations between RBC LCn3PUFAs with grip strength and or other measurements of body composition. Conclusions As a biomarker of intake, RBC LCn3PUFAs are positively associated with appendicular lean mass, a measure of skeletal muscle mass. A future study should prospectively evaluate whether higher LCn3PUFA exposure (as measured in blood) is associated with maintaining better muscle health during and following cancer treatment. Funding Sources Funding was provided by the National Cattleman's Beef Association, NIH (JKG) CA186720, Ohio Agriculture Research and Development Center and the Carol S. Kennedy Professorship.

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The Appendicular Lean Mass Index Is a Suitable Surrogate for Muscle Mass in Children with Cerebral Palsy

Journal of Nutrition ◽

10.1093/jn/nxz127 ◽

2019 ◽

Vol 149 (10) ◽

pp. 1863-1868

Author(s):

Ibrahim Duran ◽

Kyriakos Martakis ◽

Mirko Rehberg ◽

Christina Stark ◽

Anne Koy ◽

...

Keyword(s):

Skeletal Muscle ◽

Cerebral Palsy ◽

Muscle Mass ◽

Lean Mass ◽

Skeletal Muscle Mass ◽

Rehabilitation Program ◽

Appendicular Lean Mass ◽

Significant Difference ◽

Children With Cerebral Palsy ◽

Level I

ABSTRACT Background Densitometrically measured lean body mass (LBM) is often used to quantify skeletal muscle mass in children with cerebral palsy (CP). Since LBM depends on the individual's height, the evaluation of $\frac{{{\rm{LBM}}}}{{heigh{t^2}}}\ $ (lean BMI) is often recommended. However, LBM includes not only skeletal muscle mass but also the mass of skin, internal organs, tendons, and other components. This limitation applies to a far lesser extent to the appendicular lean mass index (LMIapp). Objectives The aim of the study was to evaluate skeletal muscle mass in children with CP using total lean BMI (LMItot) and LMIapp. Methods The present study was a monocentric retrospective analysis of prospectively collected data among children and adolescents with CP participating in a rehabilitation program. In total, 329 children with CP [148 females; Gross Motor Function Classification Scale (GMFCS) I, 32 children; GMFCS II, 73 children; GMFCS III, 133 children; GMFCS IV, 78 children; and GMFCS V, 13 children] were eligible for analysis. The mean age was 12.3 ± 2.75 y. Pediatric reference centiles for age-adjusted LMIapp were generated using data from NHANES 1999–2004. Low skeletal muscle mass was defined as a z score for DXA determined LMItot and LMIapp less than or equal to −2.0. Results The z scores for LMIapp were significantly lower than LMItot in children with CP, GMFCS levels II–V (P < 0.001), with the exception of GMFCS level I (P = 0.121), where no significant difference was found. The prevalence of low LMItot (16.1%; 95% CI: 16.1, 20.1%) was significantly lower (P < 0.001) than the prevalence of LMIapp (42.2%; 95% CI: 36.9, 47.9%) in the study population. Conclusions The prevalence of low skeletal muscle mass in children with CP might be underestimated by LMItot. LMIapp is more suitable for the evaluation of skeletal muscle mass in children with CP.

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The production of reactive oxygen and nitrogen species by skeletal muscle

Journal of Applied Physiology ◽

10.1152/japplphysiol.01102.2006 ◽

2007 ◽

Vol 102 (4) ◽

pp. 1664-1670 ◽

Cited By ~ 125

Author(s):

Malcolm J. Jackson ◽

Deborah Pye ◽

Jesus Palomero

Keyword(s):

Nitric Oxide ◽

Skeletal Muscle ◽

Potential Role ◽

Reactive Oxygen ◽

Oxygen Species ◽

Nitrogen Species ◽

Redox Biology ◽

Controlled Systems ◽

Potential Source

Skeletal muscle has been recognized as a potential source for generation of reactive oxygen and nitrogen species for more than 20 years. Initial investigations concentrated on the potential role of mitochondria as a major source for generation of superoxide as a “by-product” of normal oxidative metabolism, but recent studies have identified multiple subcellular sites, where superoxide or nitric oxide are generated in regulated and controlled systems in response to cellular stimuli. Full evaluation of the factors regulating these processes and the functions of the reactive oxygen species generated are important in understanding the redox biology of skeletal muscle.

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Skeletal muscle and resistance exercise training; the role of protein synthesis in recovery and remodeling

Journal of Applied Physiology ◽

10.1152/japplphysiol.00613.2016 ◽

2017 ◽

Vol 122 (3) ◽

pp. 541-548 ◽

Cited By ~ 31

Author(s):

Chris McGlory ◽

Michaela C. Devries ◽

Stuart M. Phillips

Keyword(s):

Skeletal Muscle ◽

Protein Synthesis ◽

Protein Turnover ◽

Potential Role ◽

Muscle Protein ◽

Short Review ◽

Translational Efficiency ◽

Exercise Science ◽

Resistance Exercise Training

Exercise results in the rapid remodeling of skeletal muscle. This process is underpinned by acute and chronic changes in both gene and protein synthesis. In this short review we provide a brief summary of our current understanding regarding how exercise influences these processes as well as the subsequent impact on muscle protein turnover and resultant shift in muscle phenotype. We explore concepts of ribosomal biogenesis and the potential role of increased translational capacity vs. translational efficiency in contributing to muscular hypertrophy. We also examine whether high-intensity sprinting-type exercise promotes changes in protein turnover that lead to hypertrophy or merely a change in mitochondrial content. Finally, we propose novel areas for future study that will fill existing knowledge gaps in the fields of translational research and exercise science.

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