Xia Xue, Wang Di, Yu Lei, Wang Bin, Wang Wenjing, Jiao Chunlei, Chen Xuyong, Zhang Hongyi, Chen Feng, Feng Jiexiong
Department of Pediatric Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
Department of Endocrinology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
Inflamm Res. 2021 Mar;70(3):343-358. doi: 10.1007/s00011-021-01441-6. Epub 2021 Feb 10.
Activation of intestinal macrophages is implicated in the pathogenesis of neonatal necrotizing enterocolitis (NEC), yet its precise mechanisms remain unclear.
The purpose of this study is to investigate the role of macrophages and TNF-α via an inflammatory MicroRNA in NEC.
Immunofluorescence (IF) staining of CD68, iNOS, and Arg-1 was employed to identify phenotypes of macrophage in the intestines of NEC infants and NEC mice. Expression of TNF-α, c-kit, and miR-222 was evaluated by qRT-PCR, Western blot, and immunochemical staining from the tissue samples.
Large number of M1 macrophage infiltration was found in the NEC intestines. Expression of CD68, iNOS, and TNF-α were significantly increased, while c-kit was decreased distinctly in the NEC group. In the early phase of NEC mouse model, inhibition of M1 macrophages reduced the incidence of NEC and intestinal inflammation. We found that TNF-α upregulated the expression of miRNA-222 and inhibited the expression of c-kit. Conversely, such decrease of c-kit expression could be reversed by miR-222 antagonists. Furtherly, dual-luciferase assay confirmed that c-kit can be inhibited by miR-222 directly.
Macrophages activation in NEC intestine results in an increased inflammatory response and TNF-α production, accompanied with miR-222 upregulation and c-kit suppression. Modulations of M1 macrophages, TNF-α or miR-222 may be potential therapeutic targets for NEC treatment.
肠道巨噬细胞的激活与新生儿坏死性小肠结肠炎（NEC）的发病机制有关，但其确切机制仍不清楚。
本研究旨在通过一种炎性微小RNA研究巨噬细胞和肿瘤坏死因子-α（TNF-α）在NEC中的作用。
采用免疫荧光（IF）染色检测CD68、诱导型一氧化氮合酶（iNOS）和精氨酸酶-1（Arg-1），以鉴定NEC婴儿和NEC小鼠肠道中巨噬细胞的表型。通过qRT-PCR、蛋白质免疫印迹法和免疫化学染色评估组织样本中TNF-α、c-kit和微小RNA-222（miR-222）的表达。
在NEC肠道中发现大量M1巨噬细胞浸润。NEC组中CD68、iNOS和TNF-α的表达显著增加，而c-kit明显降低。在NEC小鼠模型的早期阶段，抑制M1巨噬细胞可降低NEC的发病率和肠道炎症。我们发现TNF-α上调miR-222的表达并抑制c-kit的表达。相反，miR-222拮抗剂可逆转c-kit表达的这种降低。此外，双荧光素酶测定证实c-kit可被miR-222直接抑制。
NEC肠道中的巨噬细胞激活导致炎症反应增加和TNF-α产生，同时伴有miR-222上调和c-kit抑制。调节M1巨噬细胞、TNF-α或miR-222可能是NEC治疗的潜在靶点。
