Establishment and characterization of hTERT-immortalized porcine muscle stem cells, and their prospective uses.

Myogenic differentiation ability made porcine muscle satellite cells (MSCs) promising candidates for cultured meat production. While in vitro, porcine primary cells lose differentiation capacity, have short lifespans, and change phenotype. For immortal porcine MSCs, human telomerase reverse transcriptase (hTERT) gene was overexpressed in parental cells to restore telomerase activity and lengthen cell longevity. After selection, G418-resistant cells were expanded and passed by different generations. The hTERT-immortalized MSCs presented spindle-like shape, telomere extension, and indefinite proliferation. In comparison to parental cells, immortal cells grew more rapidly and doubled faster. Immortal MSCs expressed muscle-specific protein and gene markers, were self-renewing stem cells, and could develop into myofibers in vitro. In culture plates with more than 100 generations, immortal MSCs formed tumors, but not lower passaged cells. Today, we showed that hTERT can immortalize primary porcine MSCs and preserve their stem cell characteristics. For research and cultured meat technologies, immortality may be valuable.