摘要
Background： Porcine adipose tissue expresses orosomucoid（ORM1） mRNA, a protein with anti-inflammatory and immunomodulatory properties. Previous research has demonstrated that porcine ORM1 can reduce insulin stimulated glucose metabolism in porcine adipose tissue in vitro. The present study was designed to examine the preweaning ontogeny of ORM1 m RNA abundance in porcine subcutaneous adipose and to determine if ORM1 can regulate m RNA abundance of inflammatory cytokines that contribute to insulin resistance in primary cultures derived from neonatal porcine subcutaneous adipose tissue. Cultures were differentiated in vitro and subsequently the adipocyte containing cultures were incubated for 24 h with 0–5000 ng porcine ORM1/m L medium. Cultures were then harvested, total RNA extracted for use in reverse transcription and the m RNA abundance of cytokine m RNA quantified by real-time PCR.Results： ORM1 m RNA abundance within neonatal adipose tissue does not change from d 1 to d 21 of age and is a very small fraction relative to liver m RNA abundance. The ORM1 m RNA level in porcine adipocytes and stromalvascular cells are similar（P 〉 0.05）. Treatment with ORM1 did not affect TNFα（tumor necrosis factor α） m RNA level（P 〉 0.05）, while interleukin 6（IL6） m RNA abundance was reduced 32 % at 1,000 ng ORM1/m L（P 〈 0.01）. However,TNFα protein content in the cell culture media was reduced by ORM1 treatment（5,000 ng/m L, P 〈 0.05）, whereas ORM1 had no detectable effect on the media content of IL6（P 〉 0.05）. The reduction of macrophage migration inhibitory factor（MIF） m RNA abundance by ORM1 was dose dependent（P 〈 0.01）. Monocyte chemotactic protein（MCP） m RNA level was reduced 27 % by 1,000 ng ORM1/m L（P 〈 0.05）.Conclusions： The data suggest that ORM1 has limited effects TNFα, IL6, MIF or MCP expression at the concentrations tested. Secondly, these cytokines do not appear to contribute to the reported insulin resistance induced by ORM1 in porcine adipose tissue in vitro as an increase in the abundance of these inflammatory cytokines would be predicted during an insulin resistant state.
Background： Porcine adipose tissue expresses orosomucoid（ORM1） mRNA, a protein with anti-inflammatory and immunomodulatory properties. Previous research has demonstrated that porcine ORM1 can reduce insulin stimulated glucose metabolism in porcine adipose tissue in vitro. The present study was designed to examine the preweaning ontogeny of ORM1 m RNA abundance in porcine subcutaneous adipose and to determine if ORM1 can regulate m RNA abundance of inflammatory cytokines that contribute to insulin resistance in primary cultures derived from neonatal porcine subcutaneous adipose tissue. Cultures were differentiated in vitro and subsequently the adipocyte containing cultures were incubated for 24 h with 0–5000 ng porcine ORM1/m L medium. Cultures were then harvested, total RNA extracted for use in reverse transcription and the m RNA abundance of cytokine m RNA quantified by real-time PCR.Results： ORM1 m RNA abundance within neonatal adipose tissue does not change from d 1 to d 21 of age and is a very small fraction relative to liver m RNA abundance. The ORM1 m RNA level in porcine adipocytes and stromalvascular cells are similar（P 〉 0.05）. Treatment with ORM1 did not affect TNFα（tumor necrosis factor α） m RNA level（P 〉 0.05）, while interleukin 6（IL6） m RNA abundance was reduced 32 % at 1,000 ng ORM1/m L（P 〈 0.01）. However,TNFα protein content in the cell culture media was reduced by ORM1 treatment（5,000 ng/m L, P 〈 0.05）, whereas ORM1 had no detectable effect on the media content of IL6（P 〉 0.05）. The reduction of macrophage migration inhibitory factor（MIF） m RNA abundance by ORM1 was dose dependent（P 〈 0.01）. Monocyte chemotactic protein（MCP） m RNA level was reduced 27 % by 1,000 ng ORM1/m L（P 〈 0.05）.Conclusions： The data suggest that ORM1 has limited effects TNFα, IL6, MIF or MCP expression at the concentrations tested. Secondly, these cytokines do not appear to contribute to the reported insulin resistance induced by ORM1 in porcine adipose tissue in vitro as an increase in the abundance of these inflammatory cytokines would be predicted during an insulin resistant state.
