Silencing of long noncoding RNA PVT1 inhibits podocyte damage and apoptosis in diabetic nephropathy by upregulating FOXA1

Dong-Wei Liu,Zhang-Suo Liu,Jia-Hui Zhang,Zi-Hao Zhao,Shao-Kang Pan,Deng-Ke Jiang,Xu-Tong Wang,Feng-Xun Liu

doi:10.1038/s12276-019-0259-6

Abstract

The number of patients with diabetic nephropathy (DN) is still on the rise worldwide, and this requires the development of new therapeutic strategies. Recent reports have highlighted genetic factors in the treatment of DN. Herein, we aimed to study the roles of long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) and histone 3 lysine 27 trimethylation (H3K27me3) in DN. A model of DN was established by inducing diabetes in mice with streptozotocin. Mouse podocyte clone 5 (MPC5) podocytes and primary podocytes were cultured in normal and high glucose media to observe cell morphology and to quantify PVT1 expression. The roles of PVT1 and enhancer of zeste homolog 2 (EZH2) were validated via loss-of-function and gain-of-function in vitro experiments to identify the interactions among PVT1, EZH2, and forkhead box A1 (FOXA1). The podocyte damage and apoptosis due to PVT1 and FOXA1 were verified with in vivo experiments. PVT1 was highly expressed in MPC5 and primary podocytes in DN patients and in cultures grown in high glucose medium. A large number of CpG (C-phosphate-G) island sites were predicted at the FOXA1 promoter region, where PVT1 recruited EZH2 to promote the recruitment of H3K27me3. The silencing of PVT1 or the overexpression of FOXA1 relieved the damage and inhibited the apoptosis of podocytes in DN, as was evidenced by the upregulated expression of synaptopodin and podocin, higher expression of Bcl-2, and lower expression of Bax and cleaved caspase-3. The key findings of this study collectively indicate that the suppression of lncRNA PVT1 exerts inhibitory effects on podocyte damage and apoptosis via FOXA1 in DN, which is of clinical significance.

Highlights

Diabetic nephropathy (DN), a main cause of end-stage renal disease, occurs in 30–40% of patients who require maintenance dialysis, posing more burden on health insurance programs[1]
The plasmacytoma variant translocation 1 (PVT1) expression results conducted in Mouse podocyte clone 5 (MPC5) and primary podocytes suggested that the expression of long noncoding RNA (lncRNA) PVT1 in the HG group increased significantly compared with that in the normal glucose (NG) group (p < 0.05)
The distribution of lncRNA PVT1 in cells was detected by RNAFISH (Fig. 1b, c), indicating that lncRNA PVT1 was primarily located in the nucleus

Summary

Introduction

Diabetic nephropathy (DN), a main cause of end-stage renal disease, occurs in 30–40% of patients who require maintenance dialysis, posing more burden on health insurance programs[1]. In addition to the conventional, modifiable risk factors, such as smoking, hyperlipidemia, hypertension, and hemodynamic changes, hereditary components are regarded as potential risk factors for DN2. Despite the fact that the pathogenesis of DN has been clarified, the development of effective treatment methods for DN remains a challenging task[3]. It has been reported that the current standard therapy only achieves partial renoprotection, which greatly increases the need for novel and effective therapeutic approaches[4]. Evidence has demonstrated that DN usually occurs in familial clusters, highlighting the great significance of DN-related genetic factors in the development of DN and in the identification of more effective therapeutic strategies for DN5.

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