Figure 7

Insl6 mRNA levels are down-regulated in human polymyositis/dermatomyositis patient skeletal muscle samples. Human skeletal muscle biopsy samples were obtained from clinically diagnosed polymyositis/dermatomyositis (PM/DM) patients (n = 13). Non-myositis patient samples were used as a control (n = 14). The age and gender were matched in two groups. Total RNA was isolated and cDNA was synthesized. Relative transcript expression of human Insl6 was measured by qRT-PCR. The data were normalized by GAPDH. (a) Insl6 mRNA transcript levels are compared between control group and PM/DM patients group. Control group: 0.9825 ± 0.1725 (mean ± SEM), values (minimum 0.2621, median 0.7743 and maximum 2.402), PM/DM group: 0.5043 ± 0.1077 (mean ± SEM), values (minimum 0.0011, median 0.5471 and maximum 1.361). (b) Muscle atrophy was observed in tissue sections of PM/DM muscle biopsy samples following Gomori’s trichrome staining. The samples were rated based upon percentage atrophy of type 1 and type 2 fibers. PM/DM patients were divided into two groups based upon their Insl6 mRNA levels, and classified as the Insl6-low group (value ≤ median) and the Insl6-high group (value > median).