Application of Stem Cell Technologies to Regenerate Injured Myocardium and Improve Cardiac Function.

In the recent decades, cardiovascular diseases emerged as the major leading cause of human mortality. However, current clinical approaches still do not encompass a thorough therapeutic solution for improving heart function of the patients who suffered an extensive myocardial injury. Based on this status quo, stem cells could become a novel option, as a natural source of the new myocardium lineage cells, being capable of paracrine factors secretion, protection or even regeneration of the damaged heart muscle. Efficient stem cell-based therapy of the heart should lead to repair or/and replacement of the degenerated tissue with functional myocardial and endothelial cells. Hereon, various types of pluripotent and multipotent stem cells have been already studied in the pre-clinical and clinical settings, demonstrating their cardiomyogenic and regenerative potential. In this context, as a type of male adult stem/ progenitors, spermatogonial stem cells feature a remarkable ability for a formation of cardiovascular lineages, based on our own observations. Presented data supports the presumption, that spermatogonial stem cells not only have a suitable capacity to generate functional heart cells but can also potentially improve the function of an injured myocardium. In this review article, we first describe the essential molecular and pathophysiological mechanisms involved in the heart tissue injury. Afterwards, based on our ongoing study, we review the impact of the stem cell technologies on the regeneration therapy in cardiovascular and myocardial diseases. Particular emphasis is being put on the usability of spermatogonial stem cells in cardiac therapy.

Potency of germ cells and its relevance for regenerative medicine.

Germline stem cells, which can self-renew and generate gametes, are unique stem cells in that they are solely dedicated to transmit genetic information from generation to generation. The germ cells have a special place in the life cycle because they must be able to retain the ability to recreate the organism, a property known as developmental totipotency. Several lines of evidence have suggested the extensive proliferation activity and pluripotency of prenatal, neonatal and adult germline stem cells. We showed that adult male germline stem cells, spermatogonial stem cells, can be converted into embryonic stem cell-like cells, which can differentiate into the somatic stem cells of three germ layers. Different cell types such as vascular, heart, liver, pancreatic and blood cells could also be obtained from these stem cells. Understanding how spermatogonial stem cells can give rise to pluripotent stem cells and how somatic stem cells differentiate into germ cells could give significant insight into the regulation of developmental totipotency as well as having important implications for male fertility and regenerative medicine.