Qichen Fan1, Renhua Lu1, Mingli Zhu1, Yucheng Yan1, Xiangjiang Guo1, Yingying Qian1, Lulu Zhang1, Huili Dai1, Zhaohui Ni1, Leyi Gu2. 1. Renal Division and Molecular Cell Lab for Kidney Disease, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. 2. Renal Division and Molecular Cell Lab for Kidney Disease, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, guleyi@aliyun.com.
Abstract
BACKGROUND/AIMS: Clinical manifestation and renal histology serve as the current "gold standard" for evaluation of renal lesions in IgA nephropathy. MiR-192 is regarded as a potential noninvasive biomarker for kidney disease. We sought to elucidate a relationship between intrarenal, serum, and urinary exosomal miR-192 with renal lesions and disease progression in IgA nephropathy. METHODS: Serum and urinary exosomal miR-192 were detected and correlated with clinical and pathological parameters from consecutive IgA nephropathy patients (n = 50) and healthy control patients (n = 25). Patients then received a follow-up of 24 months after biopsy. Disease progression was defined as a 40% reduction in estimated glomerular filtration rate. Expression of miR-192 was quantified by Taqman RT-PCR. Intrarenal -miR-192 was detected in 8 IgA nephropathy patients and 4 matched patients receiving kidney nephrectomy as controls via in situ hybridization. TGF-β1 and E-cadherin expression in renal tissue was evaluated using immunohistochemistry. RESULTS: Intrarenal miR-192 was correlated with serum miR-192 (r = 0.690, p = 0.013). Both intrarenal and serum miR-192 decreased in IgA nephropathy patients and were correlated with estimated glomerular filtration ratio. Patients with lower intrarenal and serum miR-192 levels had a higher interstitial fibrosis and tubular atrophy score, more severe lesions in tubular atrophy, and interstitial inflammation. Renal E-cadherin expression was correlated (r = 0.484, p = 0.004) and TGF-β1 was inversely correlated (r = -0.527, p < 0.001) with serum miR-192 in IgA. Patients with higher serum miR-192 had a lower disease progression rate over the course of 2 years (0 vs. 16%, p = 0.028). No correlation was found in urinary exosomal miR-192 with the clinical and pathological parameters mentioned earlier. CONCLUSIONS: Lower serum miR-192 in IgA nephropathy patients indicates lower intrarenal miR-192 expression, more severe tubular atrophy, interstitial inflammation, and fibrotic tendency (with higher TGF-β and E-cadherin in renal miR-192). IgA nephropathy patients with higher serum miR-192 are less likely to have renal function decline over the course of 2 years.
BACKGROUND/AIMS: Clinical manifestation and renal histology serve as the current "gold standard" for evaluation of renal lesions in IgA nephropathy. MiR-192 is regarded as a potential noninvasive biomarker for kidney disease. We sought to elucidate a relationship between intrarenal, serum, and urinary exosomal miR-192 with renal lesions and disease progression in IgA nephropathy. METHODS: Serum and urinary exosomal miR-192 were detected and correlated with clinical and pathological parameters from consecutive IgA nephropathypatients (n = 50) and healthy control patients (n = 25). Patients then received a follow-up of 24 months after biopsy. Disease progression was defined as a 40% reduction in estimated glomerular filtration rate. Expression of miR-192 was quantified by Taqman RT-PCR. Intrarenal -miR-192 was detected in 8 IgA nephropathypatients and 4 matched patients receiving kidney nephrectomy as controls via in situ hybridization. TGF-β1 and E-cadherin expression in renal tissue was evaluated using immunohistochemistry. RESULTS: Intrarenal miR-192 was correlated with serum miR-192 (r = 0.690, p = 0.013). Both intrarenal and serum miR-192 decreased in IgA nephropathypatients and were correlated with estimated glomerular filtration ratio. Patients with lower intrarenal and serum miR-192 levels had a higher interstitial fibrosis and tubular atrophy score, more severe lesions in tubular atrophy, and interstitial inflammation. Renal E-cadherin expression was correlated (r = 0.484, p = 0.004) and TGF-β1 was inversely correlated (r = -0.527, p < 0.001) with serum miR-192 in IgA. Patients with higher serum miR-192 had a lower disease progression rate over the course of 2 years (0 vs. 16%, p = 0.028). No correlation was found in urinary exosomal miR-192 with the clinical and pathological parameters mentioned earlier. CONCLUSIONS: Lower serum miR-192 in IgA nephropathypatients indicates lower intrarenal miR-192 expression, more severe tubular atrophy, interstitial inflammation, and fibrotic tendency (with higher TGF-β and E-cadherin in renal miR-192). IgA nephropathypatients with higher serum miR-192 are less likely to have renal function decline over the course of 2 years.