Guan Yingjie, Shen Fengchen, Yao Liyuan, Zhao Ting C, Zhuang Shougang
Rhode Island Hospital, Warren Alpert Medical School of Brown University.
Shanghai East Hospital, Tongji University School of Medicine.
Res Sq. 2025 May 6:rs.3.rs-6523050. doi: 10.21203/rs.3.rs-6523050/v1.
Histone deacetylase 11 (HDAC11) is the sole member of class IV HDACs, implicated in tumor growth, immune regulation, and oxidative stress injury. Its specific role in renal fibrosis and underlying mechanisms remains unclear.
The global knockout of HDAC11 mice and FT895, a selective inhibitor of HDAC11, were utilized to assess the role of HDAC11 in renal fibrosis following unilateral ureteral obstruction (UUO) injury in mice. Immunostaining was employed to analyze renal expression of HDAC11 and infiltration of macrophages. Immunoblot analysis was used to analyze the expression and/or phosphorylation of proteins associated with partial epithelial-mesenchymal transition (pEMT) in the kidney and cultured renal proximal tubular cells (RTPCs). RT-PCR was used to analyze the expression of various proinflammatory cytokines.
HDAC11 was predominantly expressed in renal epithelial cells, with its expression increasing in the kidney following UUO. This upregulation correlated with excessive collagen deposition and was associated with increased levels of fibronectin, collagen I, and α-smooth muscle actin, alongside reduced E-cadherin expression. Both global deletion of HDAC11 and treatment with the selective inhibitor FT895 significantly reduced collagen accumulation and the expression of fibronectin and collagen I, while preserving E-cadherin levels. HDAC11 inhibition also led to a decrease in histone H3 phosphorylation at serine 10, a marker of G2/M cell cycle arrest, and reduced the expression of Snail and Twist-key transcription factors involved in pEMT. Similar effects were observed in TGFb1-stimulated renal proximal tubular cells in vitro treated with FT895 or subjected to HDAC11 silencing via siRNA. Additionally, FT895 treatment attenuated the expression of multiple pro-inflammatory cytokines and reduced macrophage infiltration in obstructed kidneys. Both pharmacological inhibition and genetic ablation of HDAC11 suppressed activation of profibrotic signaling pathways, including Smad3, STAT3, and NF-κB, in both in vitro and in vivo models.
These findings indicate that HDAC11 is crucial for renal fibrosis development by promoting pEMT and G2/M phase cell cycle arrest in renal epithelial cells through multiple profibrotic signaling pathways. Therefore, targeting HDAC11 may be a promising therapeutic strategy to alleviate renal fibrosis.
组蛋白去乙酰化酶11（HDAC11）是IV类组蛋白去乙酰化酶的唯一成员，与肿瘤生长、免疫调节和氧化应激损伤有关。其在肾纤维化中的具体作用及潜在机制尚不清楚。
利用HDAC11基因敲除小鼠和HDAC11选择性抑制剂FT895，评估HDAC11在小鼠单侧输尿管梗阻（UUO）损伤后肾纤维化中的作用。采用免疫染色分析HDAC11在肾脏中的表达及巨噬细胞浸润情况。采用免疫印迹分析肾脏和培养的肾近端小管细胞（RTPCs）中与部分上皮-间质转化（pEMT）相关蛋白的表达和/或磷酸化情况。采用RT-PCR分析多种促炎细胞因子的表达。
HDAC11主要在肾上皮细胞中表达，在UUO后其在肾脏中的表达增加。这种上调与过量的胶原沉积相关，并与纤连蛋白、I型胶原和α-平滑肌肌动蛋白水平升高以及E-钙黏蛋白表达降低有关。HDAC11的整体缺失和选择性抑制剂FT895治疗均显著减少了胶原积累以及纤连蛋白和I型胶原的表达，同时维持了E-钙黏蛋白水平。HDAC11抑制还导致丝氨酸10位点的组蛋白H3磷酸化减少，这是G2/M期细胞周期阻滞的标志物，并降低了参与pEMT的Snail和Twist关键转录因子的表达。在用FT895处理或通过siRNA使HDAC11沉默的体外TGFb1刺激的肾近端小管细胞中也观察到了类似的效果。此外，FT895治疗减弱了多种促炎细胞因子的表达，并减少了梗阻肾脏中的巨噬细胞浸润。在体外和体内模型中，HDAC11的药理抑制和基因敲除均抑制了包括Smad3、STAT3和NF-κB在内的促纤维化信号通路的激活。
这些发现表明，HDAC11通过多种促纤维化信号通路促进肾上皮细胞中的pEMT和G2/M期细胞周期阻滞，对肾纤维化的发展至关重要。因此，靶向HDAC11可能是缓解肾纤维化的一种有前景的治疗策略。
