Chronic visceral hypersensitivity is an important type of chronic pain with unknown etiology and pathophysiology. Recent studies have shown that epigenetic regulation plays an important role in the development of chro...Chronic visceral hypersensitivity is an important type of chronic pain with unknown etiology and pathophysiology. Recent studies have shown that epigenetic regulation plays an important role in the development of chronic pain conditions. However, the role of mi RNA-325-5 p in chronic visceral pain remains unknown. The present study was designed to determine the roles and mechanism of mi RNA-325-5 p in a rat model of chronic visceral pain.This model was induced by neonatal colonic inflammation(NCI). In adulthood, NCI led to a significant reduction in the expression of mi RNA-325-5 p in colon-related dorsal root ganglia(DRGs), starting to decrease at the age of4 weeks and being maintained to 8 weeks. Intrathecal administration of mi RNA-325-5 p agomir significantly enhanced the colorectal distention(CRD) threshold in a time-dependent manner. NCI also markedly increased the expression of CCL2(C-C motif chemokine ligand 2) in colon-related DRGs at the m RNA and protein levels relative to age-matched control rats. The expression of CXCL12, IL33, SFRS7, and LGI1 was not significantlyaltered in NCI rats. CCL2 was co-expressed in Neu Npositive DRG neurons but not in glutamine synthetasepositive glial cells. Furthermore, CCL2 was mainly expressed in isolectin B4-binding-and calcitonin generelated peptide-positive DRG neurons but in few NF-200-positive cells. More importantly, CCL2 was expressed in mi R-325-5 p-positive DRG neurons. Intrathecal injection of mi RNA-325-5 p agomir remarkably reduced the upregulation of CCL2 in NCI rats. Administration of Bindarit, an inhibitor of CCL2, markedly raised the CRD threshold in NCI rats in a dose-and time-dependent manner. These data suggest that NCI suppresses mi RNA-325-5 p expression and enhances CCL2 expression, thus contributing to visceral hypersensitivity in adult rats.展开更多
基金supported by grants from the National Natural Science Foundation of China (81471137, 31730040, and 81771187)the Priority Academic Program Development of Jiangsu Higher Education Institutions of China
文摘Chronic visceral hypersensitivity is an important type of chronic pain with unknown etiology and pathophysiology. Recent studies have shown that epigenetic regulation plays an important role in the development of chronic pain conditions. However, the role of mi RNA-325-5 p in chronic visceral pain remains unknown. The present study was designed to determine the roles and mechanism of mi RNA-325-5 p in a rat model of chronic visceral pain.This model was induced by neonatal colonic inflammation(NCI). In adulthood, NCI led to a significant reduction in the expression of mi RNA-325-5 p in colon-related dorsal root ganglia(DRGs), starting to decrease at the age of4 weeks and being maintained to 8 weeks. Intrathecal administration of mi RNA-325-5 p agomir significantly enhanced the colorectal distention(CRD) threshold in a time-dependent manner. NCI also markedly increased the expression of CCL2(C-C motif chemokine ligand 2) in colon-related DRGs at the m RNA and protein levels relative to age-matched control rats. The expression of CXCL12, IL33, SFRS7, and LGI1 was not significantlyaltered in NCI rats. CCL2 was co-expressed in Neu Npositive DRG neurons but not in glutamine synthetasepositive glial cells. Furthermore, CCL2 was mainly expressed in isolectin B4-binding-and calcitonin generelated peptide-positive DRG neurons but in few NF-200-positive cells. More importantly, CCL2 was expressed in mi R-325-5 p-positive DRG neurons. Intrathecal injection of mi RNA-325-5 p agomir remarkably reduced the upregulation of CCL2 in NCI rats. Administration of Bindarit, an inhibitor of CCL2, markedly raised the CRD threshold in NCI rats in a dose-and time-dependent manner. These data suggest that NCI suppresses mi RNA-325-5 p expression and enhances CCL2 expression, thus contributing to visceral hypersensitivity in adult rats.
