Zhang Yixiang, He Jiahao, Xie Fangzhou, Shan Shengzhou, Qin Jiaqi, Wang Chuandong, Li Qingfeng, Xie Yun, Fang Bin
Department of Plastic & Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
Shanghai Institute for Plastic and Reconstructive Surgery, Shanghai, China. Department of Plastic & Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
Chin Med J (Engl). 2024 Nov 20;137(22):2745-2757. doi: 10.1097/CM9.0000000000003219. Epub 2024 Sep 30.
Scleroderma is characterized by inflammation and fibrosis, predominantly occurring in the skin and extending to various parts of the body. The pathophysiology of scleroderma is multifaceted, with the current understanding including endothelial damage, inflammatory cell infiltration, and fibroblast activation in its progression. Nonetheless, the mechanism of cellular interactions and the precise spatial distribution of these cellular events within the fibrotic tissues remain elusive, highlighting a critical gap in our comprehensive understanding of scleroderma's pathogenesis.
In this study, we administered bleomycin intradermally to the dorsal skin of four individual murine models. Subsequently, skin tissues were harvested at predetermined intervals for comprehensive spatial transcriptomic analysis to determine the spatial dynamics influencing scleroderma pathogenesis. To validate the possible results from bioinformatic analysis, further in vitro and in vivo experiments were conducted.
Analysis of the spatial transcriptome revealed significant alterations in cell clusters during the progression of scleroderma. Gene Ontology analysis identified disruptions in lipid metabolism as the disease advanced. Pseudotime analysis provided evidence for a phenotypic transition from adipocytes to fibroblasts. In vitro studies demonstrated increased expression of Col1a1 and α-SMA as the disease progressed. These fibroblasts have been identified as key contributors to the increasing inflammation. Co-culturing TGF-β induced adipocytes with RAW264.7 cells resulted in overexpression of pro-inflammatory cytokines in the RAW264.7 cells. Both in vitro and in vivo experiments confirmed adipocyte loss and fibroblast formation, with transformed fibroblasts showing pronounced pro-inflammatory characteristics, highlighting their crucial role in the disease mechanism.
Our study showed the spatial distribution and dynamic alterations of various cell types during scleroderma progression. Crucially, we identified the transformation of adipocytes into fibroblasts as a key factor promoting disease advancement. These emergent fibroblasts intensify inflammation, indicating that research on these cell clusters could reveal key scleroderma mechanisms and guide future therapies.
硬皮病的特征是炎症和纤维化，主要发生在皮肤并累及身体各个部位。硬皮病的病理生理学是多方面的，目前的认识包括其进展过程中的内皮损伤、炎症细胞浸润和成纤维细胞活化。然而，细胞间相互作用的机制以及这些细胞事件在纤维化组织内的确切空间分布仍然难以捉摸，这凸显了我们对硬皮病发病机制全面理解中的关键差距。
在本研究中，我们对四个单独的小鼠模型的背部皮肤进行皮内注射博来霉素。随后，在预定的时间间隔采集皮肤组织进行全面的空间转录组分析，以确定影响硬皮病发病机制的空间动态变化。为了验证生物信息学分析可能得到的结果，我们进行了进一步的体外和体内实验。
空间转录组分析显示，在硬皮病进展过程中细胞簇发生了显著变化。基因本体分析表明，随着疾病进展，脂质代谢出现紊乱。伪时间分析为从脂肪细胞到成纤维细胞的表型转变提供了证据。体外研究表明，随着疾病进展，Col1a1和α-SMA的表达增加。这些成纤维细胞已被确定为炎症加剧的关键因素。将转化生长因子-β诱导的脂肪细胞与RAW264.7细胞共培养导致RAW264.7细胞中促炎细胞因子的过度表达。体外和体内实验均证实了脂肪细胞的丢失和成纤维细胞的形成，转化后的成纤维细胞表现出明显的促炎特征，突出了它们在疾病机制中的关键作用。
我们的研究显示了硬皮病进展过程中各种细胞类型的空间分布和动态变化。至关重要的是，我们确定脂肪细胞向成纤维细胞的转化是促进疾病进展的关键因素。这些新出现的成纤维细胞加剧了炎症，表明对这些细胞簇的研究可能揭示硬皮病的关键机制并指导未来的治疗。
