Ding Shaojie, Guo Xinyue, Zhu Libo, Wang Jianzhang, Li Tiantian, Yu Qin, Zhang Xinmei
Department of Gynecology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Zhejiang University School of Medicine, Hangzhou, China.
Ann Transl Med. 2021 Jan;9(1):29. doi: 10.21037/atm-20-2161.
Endometriosis-associated pain can be considered a type of neuropathic pain. Netrin-1 is an axon guidance cue that regulates axonal attraction or rejection in neural injury and regeneration. However, whether netrin-1 plays a role in endometriosis-associated pain remains unclear. This study aimed to determine the role of netrin-1 in endometriosis-related pain.
Peripheral blood, peritoneal fluid, and endometrial tissues were sampled from women with (n=37) and without endometriosis (n=23). Lipopolysaccharide (LPS) and interferon gamma (IFN-γ) were used to stimulate human monocytic cell lines (THP-1) and rat alveolar macrophage-derived cell lines (NR8383) to induce M1 phenotype macrophages. Serum netrin-1 concentrations, endometrial expression levels of netrin-1, and its receptors including deleted in colorectal cancer (DCC), A2B adenosine receptor (A2BAR), uncoordinated B receptor (UNC5B), uncoordinated C receptor (UNC5C) and Down's syndrome cell adhesion molecule (DSCAM) were assessed. The polarization phenotypes of the peritoneal macrophages were identified by detecting the marker expression of M1/M2 macrophages via flow cytometry. The expression levels of M1 markers and netrin-1 in THP-1/NR8383 cells were determined.
The expression levels of netrin-1 in serum and endometriotic lesions were significantly higher in women with endometriosis, and were positively correlated with the severity of endometriosis-associated pain. Netrin-1 was co-expressed with CD68 (a macrophage marker) in endometriotic lesions and was synthesized and secreted by THP-1 and NR8383 cells in the process of M1 polarization. In women with endometriosis, peritoneal macrophages were polarized towards the M1 phenotype. In addition, increased expression of DCC and A2BAR, and decreased expression of UNC5B, UNC5C and DSCAM were found in endometriotic lesions.
These results suggest that netrin-1 production by macrophages in endometriotic lesions may play an important role in endometriosis-associated pain.
子宫内膜异位症相关疼痛可被视为一种神经性疼痛。Netrin-1是一种轴突导向分子，在神经损伤和再生过程中调节轴突的吸引或排斥。然而，Netrin-1在子宫内膜异位症相关疼痛中是否起作用仍不清楚。本研究旨在确定Netrin-1在子宫内膜异位症相关疼痛中的作用。
从患有（n=37）和未患有子宫内膜异位症（n=23）的女性中采集外周血、腹腔液和子宫内膜组织。使用脂多糖（LPS）和干扰素γ（IFN-γ）刺激人单核细胞系（THP-1）和大鼠肺泡巨噬细胞衍生细胞系（NR8383）以诱导M1表型巨噬细胞。评估血清Netrin-1浓度、Netrin-1在子宫内膜中的表达水平及其受体，包括结直肠癌缺失基因（DCC）、A2B腺苷受体（A2BAR）、不协调B受体（UNC5B）、不协调C受体（UNC5C）和唐氏综合征细胞粘附分子（DSCAM）。通过流式细胞术检测M1/M2巨噬细胞的标志物表达来鉴定腹腔巨噬细胞的极化表型。测定THP-1/NR8383细胞中M1标志物和Netrin-1的表达水平。
患有子宫内膜异位症的女性血清和异位内膜病变中Netrin-1的表达水平显著更高，且与子宫内膜异位症相关疼痛的严重程度呈正相关。Netrin-1在异位内膜病变中与CD68（一种巨噬细胞标志物）共表达，并在M1极化过程中由THP-1和NR8383细胞合成和分泌。在患有子宫内膜异位症的女性中，腹腔巨噬细胞向M1表型极化。此外，在异位内膜病变中发现DCC和A2BAR表达增加，UNC5B、UNC5C和DSCAM表达降低。
这些结果表明，异位内膜病变中巨噬细胞产生的Netrin-1可能在子宫内膜异位症相关疼痛中起重要作用。
