Yong Huang,Yuting Wang,Lixin Lin,Peng Wang,Lei Jiang,Jian Liu,Xueming Wang
Aim Keloid is a benign dermal tumor with excessive hyperplasia and deposition of collagen. As a common tumor suppressor gene , miR-133a-3p has not been studied in keloid. This study will delve into the specific mechanism of miR-133a-3p in keloid. Methods Normal skin fibroblasts and keloid fibroblasts (KFs) were first isolated from patients’ normal skin and keloid, and cells were identified by morphological observation and immunofluorescence. The expressions of miR-133a-3p and extracellular matrix (ECM)-associated markers (Collagen I, III and α smooth muscle activin) were detected by Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Cell viability and apoptosis of KFs were examined by Cell Counting Kit-8 assay, flow cytometry, and Caspase-3 colorimetry . TargetScan predicted target gene for miR-133a-3p was verified by luciferase assay, qRT-PCR and Western Blot (WB). WB was used to study protein expression of TGFBR1, phosphorylated -Smad2 ( p -Smad2) and Smad2. Finally, a series of rescue experiments were performed to verify the intervention of target genes on miR-133a-3p. Results MiR-133a-3p was lowly expressed in keloid tissue and KFs. Overexpression of miR-133a-3p inhibited the expression of ECM-associated markers, reduced KFs viability, and promoted apoptosis. It was verified that interference regulator 5 (IRF5) is miR-133a-3p target gene. The rescue experiments showed that IRF5 reversed the effect of miR-133a-3p mimic on inhibiting fibrosis, and reversed the effects on promoting apoptosis and reducing cell proliferation . Conclusion Overexpressed miR-133a-3p inhibits fibrosis by down-regulating IRF5 and thus inhibiting the TGF-β/Smad2 pathway. And it also promotes KFs apoptosis and reduces proliferation.
Wei-Jia Yu,Wen-Xi Jiang,Shu-Jing Liu,Hui-Hua Li,Qiu-Yue Lin
Rationale: Infiltration of immune cells into the heart plays a crucial role in the transition from adaptive hypertrophy to heart failure (HF) following chronic pressure overload. However, the key factors in myeloid cells that regulate this process are still not well defined. Here, we studied the functional role of S100A8/A9 in myeloid cells during this transition. Methods: Cardiac hypertrophy and HF models were induced by transverse aortic constriction (TAC) for 1 to 4 weeks. The heterogeneity of CD45 + immune cells and the cellular sources of S100A8/A9 were analyzed using published single-cell RNA sequencing datasets. The effects of S100A8/A9 on TAC-induced hypertrophy and HF were verified in S100A9 knockout (KO) and bone marrow (BM)-chimeric mice and in an in vitro coculture system. Results: S100A8/A9 levels were significantly increased in HF patients and in TAC-induced HF model mice. Moreover, the TAC-induced transition from adaptive hypertrophy to HF was significantly attenuated in S100A9-KO mice and WT mice transplanted with S100A9-KO BM cells. Mechanistically, TAC-stimulated upregulation of S100A8/A9 in neutrophils induced an early inflammatory response and adaptive hypertrophy through activation of the p38 MAPK/JNK/AP-1 pathway, leading to increased production of IL-1β and chemokines (CCL2 and CCL6). These chemokines promoted the infiltration of CCR2 + macrophages to the damaged heart. Therefore, they exhibited upregulation of S100A8/A9, which led to exacerbation of inflammation, cardiac hypertrophy and fibrosis via activation of the NF-κB/NLRP3, AKT/Calcineurin A and TGF-β/Smad2 signaling pathways. Additionally, treating WT mice with the S100A9 inhibitor ABR-238901 prevented TAC-induced cardiac hypertrophy-related dysfunction. Conclusion: The present findings establish an S100A8/A9-related axis between myeloid cells and cardiac cells that drives the pressure overload-induced transition from hypertrophy to HF, suggesting that S100A8/A9 is a promising therapeutic target for this disease.