Isolation and characterization of human muscle cells.

TLDR

The study enables controlled investigation of how different cell types contribute to normal and dystrophic human muscle development. The authors isolate pure muscle cell populations by cloning, then manipulate culture conditions to maximize proliferation or differentiation, assessing capacities via clonal growth kinetics, morphological markers, and biochemical protein synthesis assays. They established a stable, standardized in vitro system for postnatal human muscle that preserves proliferative and differentiative potential after cryopreservation and reduces cellular composition variability.

Abstract

We have developed an in vitro system for the study of postnatal human muscle under standardized conditions. The technique utilizes cloning to isolate pure populations of muscle cells. By manipulating culture conditions we can maximize either proliferation or differentiation of individual clones or of clones pooled to yield mass cultures of muscle cells. The muscle phenotype is stable; cells can be stored in liquid nitrogen for long-term use without loss of proliferative or differentiative potential. We have determined proliferative capacity of muscle cells from an analysis of clonal growth kinetics; we determined differentiative capacity from morphological evidence (cell fusion, striations, contractions, and the appearance of acetylcholine receptors) and biochemical analysis of muscle protein synthesis (creatine kinase, alpha-actin, tropomyosin, and myosin light chains). Our approach eliminates the variability in cellular composition that has complicated studies of primary muscle to date. We can now study in a controlled fashion the interactions and contributions of different cell types to the development of normal and genetically dystrophic human muscle.