Medical College of Qingdao University, Qingdao, China; State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China.
State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China.
Biomed Pharmacother. 2023 May;161:114523. doi: 10.1016/j.biopha.2023.114523. Epub 2023 Mar 15.
Diabetic keratopathy (DK), the diabetic complication in the cornea, is characterized by the delayed epithelial regeneration and sensory nerve degeneration. The involvement of limbal stem/progenitor cells (LSPCs) dysfunction has been reported, however the pathogenic mechanisms remain unclear. Here, we confirmed the dysfunction of LSPCs in diabetic mouse and human corneas. The sympathetic nerve in the cornea was adjacent to LSPCs, and the sympathetic overactivation was found in diabetic mice. Surgical and pharmacological ablation of sympathetic nerves rescued the LSPCs function and promoted corneal epithelial regeneration in diabetic mice. In contrast, both topical norepinephrine (NE) application and chemogenetic sympathetic overactivation directly impaired the stemness and proliferation characteristics of LSPCs, as well as the normal epithelial regeneration. Moreover, we identified that β2-adrenoceptor (Adrb2) was the predominant adrenergic receptor expressed in LSPCs by corneal limbal single-cell sequencing and real time PCR (RT-PCR) analysis of sorted LSPCs. The Adrb2 knockout mice exhibited the enhancement of epithelial regeneration and LSPCs function, compared with the wild-type mice. Similarly, topical application of the Adrb2 specific antagonist ICI 118, 551 effectively accelerated diabetic corneal epithelial regeneration with the restored LSPCs function. Mechanistically, sonic hedgehog (Shh) activity mediated the downstream effects of NE-Adrb2 signaling pathway in regulating LSPCs and epithelial regeneration. Taken together, our data revealed the involvement of sympathetic overactivation in the impairment of diabetic LSPCs function and corneal epithelial regeneration through the NE-Adrb2-Shh signaling pathway. The interference of sympathetic overactivation may provide novel treatment strategies for diabetic keratopathy.
糖尿病性角膜病变(DK)是角膜的糖尿病并发症,其特征为上皮细胞再生和感觉神经退行性变延迟。已有报道称,角膜缘干细胞/祖细胞(LSPCs)功能障碍与糖尿病有关,但发病机制尚不清楚。在这里,我们证实了糖尿病小鼠和人眼角膜中 LSPCs 的功能障碍。角膜中的交感神经与 LSPCs 相邻,并且在糖尿病小鼠中发现交感神经过度激活。手术和药理学消融交感神经可挽救 LSPCs 功能并促进糖尿病小鼠的角膜上皮再生。相比之下,局部去甲肾上腺素(NE)应用和化学遗传交感神经过度激活均直接损害 LSPCs 的干性和增殖特性,以及正常的上皮再生。此外,我们通过角膜缘单细胞测序和对分选的 LSPCs 的实时 PCR(RT-PCR)分析鉴定出,β2-肾上腺素能受体(Adrb2)是 LSPCs 中表达的主要肾上腺素能受体。与野生型小鼠相比,Adrb2 敲除小鼠表现出增强的上皮再生和 LSPCs 功能。同样,局部应用 Adrb2 特异性拮抗剂 ICI 118,551 可有效加速糖尿病性角膜上皮再生,并恢复 LSPCs 功能。在机制上,Shh 活性介导了 NE-Adrb2 信号通路在调节 LSPCs 和上皮再生中的下游效应。总之,我们的数据揭示了交感神经过度激活通过 NE-Adrb2-Shh 信号通路参与糖尿病 LSPCs 功能障碍和角膜上皮再生的损伤。干扰交感神经过度激活可能为糖尿病性角膜病变提供新的治疗策略。