Expression of Regulated Oncogen-Alpha by Primary Hepatocytes Following Isolation and Heat Shock Stimulation

High levels of regulated oncogen-alpha (GRO-a) expression have been observed in the liver. GRO-a stimulates proliferation of epithelial cells and induction of rolling and extravascular migration of neutrophils and mononuclear cells. Given the above observations, this chemokine was chosen to be analyzed in freshly isolated and cultured hepatocytes. In this study, hepatocytes (2×106 cell/ml) were isolated from male Sprague Dawley rat liver and cultured on plates that were pre-coated with collagen type-I matrix. The western and northern blot analyses were employed to detect GRO-a at the protein and mRNA levels in freshly isolated and cultured hepatocytes in response to isolation and heat shock stresses. GRO-a was shown to be expressed by isolated rat hepatocytes immediately after isolation and early culture and decreased with time. mRNA was also expressed in freshly isolated cells (0 h) and did not decrease after 48h of culture and further time points (P<0.01). These results also demonstrated that expression of GRO-a by hepatocytes increased in response to heat shock at different time points in comparison with the control (P<0.01). These results demonstrated that the isolation and heat shock stresses induced the expression of GRO-a in hepatocytes in a time-dependent manner. Thus, it seems that hepatocytes mimic the experiences that the liver encounters after injury in vivo. In such a situation, liver produces stress related agents like chemokines to overcome injurious conditions.