DOI: 10.4103/wjtcm.wjtcm_88_26 ISSN: 2311-8571
Mechanism of Electroacupuncture Pretreatment on M1 Macrophage Polarization in A Rat Model of Primary Dysmenorrhea Based on the Nuclear Factor-κB/Nucleotide-Binding Oligomerization Domain-Like Receptor Protein 3 Pathway
Xiao Xue, Xiang Li, Yu Liu, Yan-Rong Wei, Yu Jiang, Ming-Kun Yue, Hao-Lin Jin, Haiying Li, Yan Huang, Xin Yi, Yi-Chen Qin, Zhao-Xia Peng, Xin Liu, Ming Yi
Objective:
The objective is to explore the effect of electroacupuncture (EA) on M1 macrophage polarization mediated by the nuclear factor-κB (NF-κB)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) in a primary dysmenorrhea (PDM) rat model.
Materials and Methods:
A total of 24 female Sprague–Dawley rats were randomly divided into the Saline, Model, EA, and JSH-23 (a positive control group treated with an NF-κB inhibitor) groups (
n
= 6 per group). Except for the saline group, the other three groups were established as PDM models via the combined administration of estradiol benzoate and oxytocin. Rats in the estrus cycle were injected subcutaneously with estradiol benzoate in the femoral region for 10 consecutive days (0.5 mg/d on the 1
st
and 10
th
days, and 0.2 mg/d from the 2
nd
to the 9
th
day). On the 11
th
day, each rat in these groups received an intraperitoneal injection of 2 U of oxytocin. The EA group received EA at the Sanyinjiao (Spleen Meridian 6) and Guanyuan (Conception Vessel 4) acupoints for 20 min once daily for 10 consecutive days. The JSH-23 group was intraperitoneally injected with JSH-23 solution at 3 mg/kg once daily for 10 consecutive days. On the 11
th
day, writhing behavior was compared across the groups. Hematoxylin and eosin (H and E) staining and transmission electron microscopy were performed to visualize the pathological morphology and ultrastructure of endometrial tissues. Enzyme-linked immunosorbent assay was used to quantify serum prostaglandin F2α (PGF2α), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS). Western blot was performed to determine the expression of phosphorylated NF-κB p65 (P-NF-κB p65), NF-κB, NLRP3, CD86, and iNOS.
Results:
Compared with the saline group, the model group showed pronounced writhing reactions, accompanied by pathological inflammatory injuries in the uterus, relatively severe edema in M1-polarized macrophages, extensive matrix dissolution, and significant swelling or disintegration of organelles. Serum levels of PGF2α, TNF-α, and iNOS and the expressions of various proteins in uterine tissue all significantly increased (
P
< 0.01,
P
< 0.05). In contrast to the model group, rats in each treatment group exhibited increased writhing latency, alleviated uterine pathological inflammatory injury, relatively mild edema in M1-polarized macrophages, partial dissolution of the intracellular matrix, and only a few evident organelle swellings. Serum levels of PGF2α, TNF-α, and iNOS and the protein expressions of P-NF-κB p65, NF-κB p65, NLRP3, CD86, and iNOS were significantly decreased (
P
< 0.01,
P
< 0.05). Compared with the JSH-23 group, CD86 and iNOS levels were significantly higher in the EA group (
P
< 0.01,
P
< 0.05).
Conclusions:
EA may inhibit NLRP3 inflammasome by suppressing NF-κB transcription, thereby alleviating downstream inflammatory responses and cell damage. Simultaneously, it inhibits the pro-inflammatory M1 polarization of macrophages, mitigating PDM. Thus, EA serves as a potential alternative to the NF-κB inhibitor JSH-23.