Macular corneal dystrophy (MCD) is classified as corneal stromal dystrophy. In this study, we retrospectively reviewed the surgical outcomes of 118 MCD patients receiving surgical treatment in the past 30 years and found patients receiving penetrating keratoplasty had the lowest recurrence rate 13.75%, compared with 40.91% patients receiving deep anterior lamellar keratoplasty and 25% receiving phototherapeutic keratectomy. Transcriptomic analysis in human corneal single-cell sequencing atlas found the MCD pathogenic gene CHST6 was abundant in corneal endothelium rather than other cell types. CHST6 protein showed a similar expression pattern to its mRNA. The mouse homologous gene Chst5 was 120-fold higher in corneal endothelium than in the epithelial and stromal layers. Mice with specifically Chst5 knockdown in the endothelial layer by microinjection of the adeno-associated virus serotype 9 - shRNA plasmids into the anterior chamber, rather than Chst5 knockdown into the stroma, showed MCD-like phenotypes. Corneal opacification and abnormally larger collagen fibrils were observed in the endothelial Chst5 knockdown mice. The same corneal characteristics were observed after overexpressing human CHST6 mutant R50H in the mouse endothelium. These observations indicating the pathogenesis of MCD is more related to the corneal endothelium rather than the stroma.

中文翻译：

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CHST6 相关黄斑角膜营养不良：内皮问题

黄斑角膜营养不良（MCD）被归类为角膜基质营养不良。在本研究中，我们回顾了过去 30 年接受手术治疗的 118 名 MCD 患者的手术结果，发现接受穿透性角膜移植术的患者复发率最低，为 13.75%，而接受深前板层角膜移植术的患者为 40.91%，接受手术治疗的患者为 25%。光疗角膜切除术。人角膜单细胞测序图谱中的转录组学分析发现 MCD 致病基因CHST6在角膜内皮而非其他细胞类型中含量丰富。CHST6 蛋白显示出与其 mRNA 相似的表达模式。小鼠同源基因Chst5角膜内皮细胞比上皮和基质层高 120 倍。通过将腺相关病毒血清型 9 - shRNA 质粒显微注射到前房，而不是将Chst5敲低到基质中，在内皮层中具有特异性Chst5敲低的小鼠显示出 MCD 样表型。在内皮Chst5敲低小鼠中观察到角膜混浊和异常大的胶原纤维。在小鼠内皮中过表达人CHST6突变体 R50H后，观察到相同的角膜特征。这些观察结果表明 MCD 的发病机制更多地与角膜内皮而不是基质有关。