Department of Endocrinology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China.
Front Endocrinol (Lausanne). 2023 Jan 13;13:1013018. doi: 10.3389/fendo.2022.1013018. eCollection 2022.
Diabetic foot ulcer (DFU) represents a highly-prevalent complication of diabetes mellitus (DM). Herein, the current study sought to identify the role of growth differentiation factor 10 (GDF-10) in wound healing in DFU regulation of the transforming growth factor-beta 1 (TGF-β1)/Smad3 pathway.
DM- and DFU-related microarray datasets GSE29221 and GSE134431 were firstly retrieved, and weighted gene co-expression network analysis (WGCNA) was carried out to construct a co-expression network affecting wound healing in DFU, followed by differential analysis. A protein-protein interaction (PPI) network of the DFU-related genes was subsequently constructed, and the core genes and signaling pathways in DFU were screened with the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional analyses. A DFU rat model was constructed for mechanism verification of the effect of GDF-10 on wound healing in DFU.
WGCNA screened five co-expression modules, and the brown module was most closely-related to DM. Clustering analysis screened 4417 candidate genes, of which 175 differential genes were associated with wound healing, further involved in TGF-β1/Smad3 signaling pathway regulation of wound healing in DFU. The PPI network analysis predicted that GDF-10 might regulate the TGF-β1/Smad3 signaling pathway to participate in DFU development. Results of animal experimentation showed that the wound healing rates of NFU, DFU, DFU + GDF and GDF + SIS3 groups on the 22nd day were (87.66 ± 6.80)%, (56.31 ± 7.29)%, (71.64 ± 9.43)% and (55.09 ± 7.13)%, respectively. Besides, the expression of TGF-β1 in NFU, DFU, DFU + GDF and GDF + SIS3 groups was 0.988 ± 0.086, 0.297 ± 0.036, 0.447 ± 0.044, and 0.240 ± 0.050, respectively, and that of Smad3 was 1.009 ± 0.137, 0.145 ± 0.017, 0.368 ± 0.048, and 0.200 ± 0.028, respectively. Specifically, GDF-10 exerted a significant diminishing effect on fasting blood glucose level, and promoted wound healing in DFU rats, in addition to up-regulation of VEGF, FGF, Ang-1, TGF-β1, Smad3 and enhancement of IL-1b, IL-6, TNF-a and MMP-9, thereby promoting fibroblast proliferation, collagen deposition and angiogenesis.
Our findings highlight that GDF-10 may promote angiogenesis by activating TGF-β1/Smad3 signaling, thereby promoting wound healing in DFU rats.
糖尿病足溃疡（DFU）是糖尿病（DM）的一种高发并发症。在此，本研究旨在探究生长分化因子 10（GDF-10）在 DFU 创面愈合中的作用及其对转化生长因子-β1（TGF-β1）/Smad3 通路的调控作用。
首先检索了 DM 和 DFU 相关的微阵列数据集 GSE29221 和 GSE134431，进行加权基因共表达网络分析（WGCNA）以构建影响 DFU 创面愈合的共表达网络，随后进行差异分析。接着构建了 DFU 相关基因的蛋白质-蛋白质相互作用（PPI）网络，并通过基因本体论和京都基因与基因组百科全书的功能分析筛选 DFU 中的核心基因和信号通路。最后构建了 DFU 大鼠模型以验证 GDF-10 对 DFU 创面愈合的影响机制。
WGCNA 筛选出五个共表达模块，其中棕色模块与 DM 最为密切相关。聚类分析筛选出 4417 个候选基因，其中 175 个差异基因与创面愈合有关，进一步参与了 TGF-β1/Smad3 信号通路对 DFU 创面愈合的调控。PPI 网络分析预测 GDF-10 可能通过调控 TGF-β1/Smad3 信号通路参与 DFU 的发生发展。动物实验结果显示，第 22 天时 NFU、DFU、DFU+GDF 和 GDF+SIS3 组的创面愈合率分别为（87.66±6.80）%、（56.31±7.29）%、（71.64±9.43）%和（55.09±7.13）%。此外，NFU、DFU、DFU+GDF 和 GDF+SIS3 组 TGF-β1 的表达分别为 0.988±0.086、0.297±0.036、0.447±0.044 和 0.240±0.050，Smad3 的表达分别为 1.009±0.137、0.145±0.017、0.368±0.048 和 0.200±0.028。具体而言，GDF-10 可显著降低空腹血糖水平，并促进 DFU 大鼠的创面愈合，同时上调 VEGF、FGF、Ang-1、TGF-β1、Smad3，并增强 IL-1b、IL-6、TNF-a 和 MMP-9，从而促进成纤维细胞增殖、胶原沉积和血管生成。
本研究结果表明，GDF-10 可能通过激活 TGF-β1/Smad3 信号通路促进血管生成，从而促进 DFU 大鼠的创面愈合。
