A Historic Recapitulation of Myoblast Transplantation

Background —Graft survival after skeletal myoblast transplantation is affected by various pathological processes caused by environmental stress. Heat shock is known to afford protection of several aspects of cell metabolism and function. We hypothesized that prior heat shock treatment of graft cells would improve their survival after cell transplantation. Methods and Results —L6 rat skeletal myoblasts expressing β-galactosidase (β-gal) were subjected to heat shock (42°C, 1 hour). Increased expression of heat shock protein 72 was detected 24 hours later in the heat-shocked cells. After hypoxia-reoxygenation in vitro, lactate dehydrogenase leakage was significantly attenuated in the heat-shocked cells; in addition, the percentage of early apoptosis was lower in this group measured by flow cytometry with annexin V staining. For the in vivo study, 1×10 6 heat-shocked (hsCTx) or normal-cultured (CTx) myoblasts were infused into the explanted rat hearts through the coronary artery followed by heterotopic heart transplantation. β-gal activity was significantly higher in the hsCTx group after cell transplantation, with an estimated 8×10 6 surviving cells per heart in the hsCTx group and 5×10 6 cells in the CTx group on day 28. Discrete loci of grafted cells were globally observed in the myocardium of the hsCTx and CTx groups, with a higher frequency in the hsCTx group. Surviving myoblasts occasionally differentiated into myotubes and had integrated with the native cardiomyocytes. Conclusions —Heat-shocked skeletal myoblasts demonstrated improved tolerance to hypoxia-reoxygenation insult in vitro and enhanced survival when grafted into the heart. Heat shock treatment could be useful in improving graft cell survival in cell transplantation.

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Myostatin: genetic variants, therapy and gene doping

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502012000300003 ◽

2012 ◽

Vol 48 (3) ◽

pp. 369-377 ◽

Cited By ~ 4

Author(s):

André Katayama Yamada ◽

Rozangela Verlengia ◽

Carlos Roberto Bueno Junior

Keyword(s):

Athletic Performance ◽

Genetic Variants ◽

Muscle Hypertrophy ◽

Muscle Wasting ◽

Genetic Manipulation ◽

Muscle Growth ◽

Gene Doping ◽

Oxidative Phenotype ◽

Illicit Use ◽

Myoblast Transplantation

Since its discovery, myostatin (MSTN) has been at the forefront of muscle therapy research because intrinsic mutations or inhibition of this protein, by either pharmacological or genetic means, result in muscle hypertrophy and hyperplasia. In addition to muscle growth, MSTN inhibition potentially disturbs connective tissue, leads to strength modulation, facilitates myoblast transplantation, promotes tissue regeneration, induces adipose tissue thermogenesis and increases muscle oxidative phenotype. It is also known that current advances in gene therapy have an impact on sports because of the illicit use of such methods. However, the adverse effects of these methods, their impact on athletic performance in humans and the means of detecting gene doping are as yet unknown. The aim of the present review is to discuss biosynthesis, genetic variants, pharmacological/genetic manipulation, doping and athletic performance in relation to the MSTN pathway. As will be concluded from the manuscript, MSTN emerges as a promising molecule for combating muscle wasting diseases and for triggering wide-ranging discussion in view of its possible use in gene doping.

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