Department of Ophthalmology of Tongji Hospital and Laboratory of Clinical and Visual Sciences of Tongji Eye Institute, School of Medicine, Tongji University, Shanghai, China.
Stem Cell Research Center, School of Medicine, Tongji University, Shanghai, China.
Invest Ophthalmol Vis Sci. 2024 Sep 3;65(11):1. doi: 10.1167/iovs.65.11.1.
This study aimed to explore the impact of HSPA13 on epithelial-mesenchymal transition (EMT) in retinal pigment epithelial (RPE) cells and proliferative vitreoretinopathy (PVR) development, along with its associated molecular mechanisms.
HSPA13 expression was evaluated in epiretinal membranes (ERMs) from patients with PVR using immunohistochemistry. The effects of HSPA13 knockdown on TGFβ1-induced EMT in hESC-RPE cells were studied through quantitative PCR (qPCR), Western blot, and wound healing assays. Intracellular Ca2+ levels were measured using Fluo-8/AM incubation. A rat PVR model was induced by the intravitreal injection of RPE cells combined with platelet-rich plasma (PRP). RNA-seq was applied to study the molecular mechanism of HSPA13 knockdown-mediated EMT inhibition.
HSPA13 was found in human ERMs and its expression increased with TGFβ1 treatment in hESC-RPE cells. Knockdown of HSPA13 inhibited TGFβ1-induced EMT and migration. In the PVR rat model, HSPA13 was expressed in the ERMs and its knockdown in RPE cells reduced the development of PVR. Consistent with these observations, RNA-seq showed a global suppression of TGFβ1-induced EMT and migration by shHSPA13 in RPE cells. Mechanistically, TGFβ1 treatment increased intracellular Ca2+ levels, leading to an upregulation of HSPA13 expression. Downregulation of HSPA13 hindered the phosphorylation of PI3K/Akt in TGFβ1-induced RPE cells.
Our study revealed the involvement of HSPA13 in PVR development, as well as in TGFβ1-induced EMT of RPE through the PI3K/Akt signaling pathway. Targeting HSPA13-related pathways involved in regulating EMT in RPE cells could serve as a novel therapeutic approach for patients with PVR.
本研究旨在探讨 HSPA13 对视网膜色素上皮（RPE）细胞上皮-间充质转化（EMT）和增生性玻璃体视网膜病变（PVR）发展的影响及其相关分子机制。
采用免疫组织化学法检测 PVR 患者眼内膜中的 HSPA13 表达。通过实时定量 PCR（qPCR）、Western blot 和划痕愈合实验研究 HSPA13 敲低对 TGFβ1 诱导的 hESC-RPE 细胞 EMT 的影响。通过 Fluo-8/AM 孵育测量细胞内 Ca2+水平。通过向玻璃体内注射 RPE 细胞与富含血小板的血浆（PRP）诱导大鼠 PVR 模型。应用 RNA 测序研究 HSPA13 敲低介导的 EMT 抑制的分子机制。
在人眼内膜中发现了 HSPA13，其表达随着 TGFβ1 处理在 hESC-RPE 细胞中增加。HSPA13 敲低抑制 TGFβ1 诱导的 EMT 和迁移。在 PVR 大鼠模型中，HSPA13 在 ERM 中表达，其在 RPE 细胞中的敲低减少了 PVR 的发展。与这些观察结果一致，RNA 测序显示 shHSPA13 在 RPE 细胞中全面抑制了 TGFβ1 诱导的 EMT 和迁移。在机制上，TGFβ1 处理增加了细胞内 Ca2+水平，导致 HSPA13 表达上调。下调 HSPA13 阻碍了 TGFβ1 诱导的 RPE 细胞中 PI3K/Akt 的磷酸化。
本研究揭示了 HSPA13 参与 PVR 发展以及 TGFβ1 诱导的 RPE 细胞 EMT 的机制，通过 PI3K/Akt 信号通路。靶向 RPE 细胞中 EMT 调节相关的 HSPA13 相关途径可能成为 PVR 患者的一种新的治疗方法。
