尿沉渣中钙信号相关mRNA作为IgA肾病足细胞损伤无创性指标的研究

<正>IgA肾病(IgA nephropathy,IgAN)是目前最常见的原发性慢性肾小球疾病,5%～25%的IgAN患者10年内进展为终末期肾脏病(end-stage renal disease,ESRD),需行肾脏替代治疗^1]。近年来,足细胞在IgAN中,致病作用受到更多关注,足细胞损伤与蛋白尿及IgAN病情进展正相关^2]。

Study on calcium signal related mRNA in urinary sediment as noninvasive indicator of podocytes injury in IgA nephropathy

Objective To assess whether TRPC6, Calpain mRNA, Talin-1 mRNA and synaptopodin mRNA related to calcium signaling pathway in urinary sediment can be used as noninvasive monitoring indicators to evaluate IgA nephropathy (IgAN) podocytes injury. Methods 36 patients with IgAN were selected as subjects, clinical data, renal biopsy pathology and urine samples were collected, and urine samples of 8 healthy people were collected as control group. Calcium signal-related protein TRPC6, Calpain, skeleton proteins Talin-1, and synaptopodin mRNA were extracted from urinary sediment, respectively. The different of mRNA between case group and healthy control group were compared, and the relationship between urinary TRPC6 mRNA and TRPC6 expression in renal tissue was determined. The correlation between urine mRNA level and clinicopathological index was analyzed, and the dynamic monitoring was performed after treatment. Results Compared with healthy control group, Calpain-1 mRNA in urine of IgAN group was significantly different from that of healthy group (P< 0.05), and TRPC6 mRNA showed a significant increase trend. Urinary TRPC6 mRNA level can reflect TRPC6 deposition in renal tissue. Urinary TRPC6 mRNA was positively correlated with albuminuria grading level (r=0.407, p=0.049), and the degree of podocytes fusion (r=0.452, p=0.027). Urinary Calpain mRNA was positively correlated with albuminuria grading level (r=0.493, p=0.014), and MAP was also positively correlated (r=0.469, p=0.021). Urine TRPC6 mRNA level and Calpain-1 mRNA expression in podocyte-positive patients were higher than those in podocyte-negative group (p<0.05). After 2 months of treatment, the levels of urinary TRPC6 mRNA and Calpain-1 mRNA were decreased with the decrease of 24-hour urinary protein quantity and MAP, with statistical difference (p=0.042, p=0.009). Conclusion TRPC6 mRNA and Calpain mRNA may be used as noninvasive monitoring indicators to evaluate podocyte injury and efficacy in IgA nephropathy.