Apoptosis in capillary endothelial cells in ageing skeletal muscle
نویسندگان
چکیده
The age-related loss of skeletal muscle mass and function (sarcopenia) is a consistent hallmark of ageing. Apoptosis plays an important role in muscle atrophy, and the intent of this study was to specify whether apoptosis is restricted to myofibre nuclei (myonuclei) or occurs in satellite cells or stromal cells of extracellular matrix (ECM). Sarcopenia in mouse gastrocnemius muscle was characterized by myofibre atrophy, oxidative type grouping, delocalization of myonuclei and ECM fibrosis. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) indicated a sharp rise in apoptosis during ageing. TUNEL coupled with immunostaining for dystrophin, paired box protein-7 (Pax7) or laminin-2α, respectively, was used to identify apoptosis in myonuclei, satellite cells and stromal cells. In adult muscle, apoptosis was not detected in myofibres, but was restricted to stromal cells. Moreover, the age-related rise in apoptotic nuclei was essentially due to stromal cells. Myofibre-associated apoptosis nevertheless occurred in old muscle, but represented < 20% of the total muscle apoptosis. Specifically, apoptosis in old muscle affected a small proportion (0.8%) of the myonuclei, but a large part (46%) of the Pax7(+) satellite cells. TUNEL coupled with CD31 immunostaining further attributed stromal apoptosis to capillary endothelial cells. Age-dependent rise in apoptotic capillary endothelial cells was concomitant with altered levels of key angiogenic regulators, perlecan and a perlecan domain V (endorepellin) proteolytic product. Collectively, our results indicate that sarcopenia is associated with apoptosis of satellite cells and impairment of capillary functions, which is likely to contribute to the decline in muscle mass and functionality during ageing.
منابع مشابه
Simultaneous Effect of Resistance Training and Stem Cell Injection on Blood Glucose Levels, Insulin Resistance, Caspase 3 And 7 As Indicators of Skeletal Muscle Apoptosis in STZ-Induced Male Diabetic Rats
Background: The aim of the present study was to investigate the simultaneous effect of resistance training and stem cell injection on the levels of some indicators of skeletal muscle apoptosis in STZ-induced diabetic male rats. Methods: In this study, 30 rats were randomly divided into 5 groups. Rats in the diabetic group and the diabetic group + stem cell injection had a total of 17 sessions...
متن کاملThe Effect of Resistance Training and Endothelial Stem Cell Injection on Βeta-Actin, Phosphorylated and Total AKT of Skeletal Muscle in Type 1 Diabetic Rats
Background: Type 1 diabetes is associated with decreased skeletal muscle capillary and improper regulation of angiogenesis pathways in skeletal muscle. This research intended to study the effect of resistance training and endothelial stem cell injection on βeta-actin, phosphorylated and total AKT of skeletal muscle in type 1 diabetic rats. Methods: In this experimental study, 36 male Wistar ra...
متن کامل-Catenin Overexpression Augments Angiogenesis and Skeletal Muscle Regeneration Through Dual Mechanism of Vascular Endothelial Growth Factor–Mediated Endothelial Cell Proliferation and Progenitor Cell Mobilization
Objective— -Catenin plays a critical role in directing cell fate during embryogenesis, and uncontrollable activation leads to cancers, suggesting its importance in cell survival and proliferation. However, little is known regarding its role in endothelial cell (EC) and skeletal muscle proliferation and progenitor cell mobilization. Methods and Results— -Catenin enhanced ECs proliferation, prote...
متن کاملCapillary regression in vascular endothelial growth factor-deficient skeletal muscle.
Skeletal muscle angiogenesis is an important physiological adaptation to increased metabolic demand, possibly dependent on vascular endothelial growth factor (VEGF), the increased expression of which is a known early response to exercise. To test the hypothesis that VEGF is essential to muscle capillary maintenance, we evaluated the consequences of targeted skeletal muscle inhibition of VEGF ex...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 13 شماره
صفحات -
تاریخ انتشار 2014