Zhao Jiamin, Zhang Shuangyi, Bai Yunjie, Gong Zhiguo, Bao Wenhui, Yu Zhuoya, Liu Bo, Mao Wei, Hasi Surong
Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, Hohhot, 010011, China.
Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China.
Sci Rep. 2025 Apr 19;15(1):13612. doi: 10.1038/s41598-025-97729-2.
Mixed lineage kinase domain-like protein (MLKL), a critical necroptosis effector, is strongly linked to inflammation, a key component of skin wound healing. However, its precise role in the wound healing process remains inadequately characterized. This study revealed sustained MLKL overexpression throughout the wound healing process, not limited to the early inflammation phase. Wound healing was delayed in MLKL-deficient (MLKL) mice compared to wild type C57BL/6J (MLKL) mice, with impaired morphological and pathological recovery. MLKL deficiency reduced the synthesis of inflammatory factors (IL-6, TNF-α, PGE), tissue repair molecules (EGF, VEGF, ERα, MMP-9), and apoptosis markers (Caspase-3, p53, Bcl-2) at wound site. Subsequently, a co-culture system was established to explore the roles of MLKL in macrophage-fibroblast interactions. M1 or M2 macrophages (M1ø or M2ø) were co-cultured with fibroblast-conditioned medium (MFbCM), and fibroblasts were co-cultured with macrophage-conditioned medium (M1ø CM or M2ø CM). The results indicated that MLKL M1ø CM and M2ø CM significantly increased ERα, VEGF and MMP-9 protein expression levels in fibroblasts, whereas this effect was impaired when MLKL M1ø CM or M2ø CM were used. Similarly, MLKL MFbCM upregulated IL-6, NO, and TNF-α in M1ø and IL-10, arginase, and Ym-1 in M2ø, but these effects were diminished with MLKL MFbCM treatment. These results indicate bidirectional crosstalk between macrophages and fibroblasts, in which MLKL plays a role. Additionally, PGE was identified as a downstream mediator of MLKL-mediated interactions between macrophages and fibroblasts. In conclusion, these findings identify MLKL as a multifunctional regulator in skin wound healing in mice.
混合谱系激酶结构域样蛋白(MLKL)是一种关键的坏死性凋亡效应蛋白,与炎症密切相关,而炎症是皮肤伤口愈合的关键组成部分。然而,其在伤口愈合过程中的具体作用仍未得到充分阐明。本研究揭示,在整个伤口愈合过程中MLKL持续过表达,而非仅限于早期炎症阶段。与野生型C57BL/6J小鼠相比,MLKL基因敲除(MLKL-/-)小鼠的伤口愈合延迟,形态和病理恢复受损。MLKL基因缺失降低了伤口部位炎症因子(IL-6、TNF-α、PGE)、组织修复分子(EGF、VEGF、ERα、MMP-9)和凋亡标志物(Caspase-3、p53、Bcl-2)的合成。随后,建立了共培养系统以探究MLKL在巨噬细胞-成纤维细胞相互作用中的作用。将M1或M2巨噬细胞(M1ø或M2ø)与成纤维细胞条件培养基(MFbCM)共培养,将成纤维细胞与巨噬细胞条件培养基(M1ø CM或M2ø CM)共培养。结果表明,MLKL-/- M1ø CM和M2ø CM显著增加了成纤维细胞中ERα、VEGF和MMP-9蛋白表达水平,而使用MLKL-/- M1ø CM或M2ø CM时这种效应受损。同样,MLKL-/- MFbCM上调了M1ø中的IL-6、NO和TNF-α以及M2ø中的IL-10、精氨酸酶和Ym-1,但MLKL-/- MFbCM处理后这些效应减弱。这些结果表明巨噬细胞与成纤维细胞之间存在双向串扰,其中MLKL发挥作用。此外,PGE被确定为MLKL介导的巨噬细胞与成纤维细胞相互作用的下游介质。总之,这些发现确定MLKL为小鼠皮肤伤口愈合中的多功能调节因子。