RESUMO
OBJECTIVES: To observe the effects of electroacupuncture(EA) on local inflammatory mediators and macrophage polarization, and immune cells in the spleen of mice with chronic inflammatory pain induced by complete Freund's adjuvant (CFA) in the hind paw, so as to investigate the immunoinflammatory regulatory mechanisms of EA in relieving pain and swelling in mice with chronic inflammatory pain. METHODS: Thirty C57BL/6 mice were randomly divided into control, model, and EA groups, with 10 mice in each group. Chronic inflammatory pain model were established by subcutaneous injection of 20 µL CFA solution in the left hind paw for 7 consecutive days. After modeling, mice in the EA group received EA at bilateral "Zusanli"(ST36) for 20 min (2 Hz/100 Hz, 1 mA) once a day for 18 consecutive days. Mechanical pain threshold, heat pain thresholds, and paw thickness were measured before and after mode-ling, and after interventions. Western blot was used to detect the expression of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, and NOD-like receptor protein 3 (NLRP3) in the paw tissue. Immunohistochemistry was used to detect the positive expression of M1-type macrophage marker inducible nitric oride synthase (iNOS) and M2-type marker CD206 in the paw, and flow cytometry was used to detect the proportion of F4/80+ CD11b+ macrophages, Ly6G+ CD11b+ neutrophils, and CD25+ Foxp3+ regulatory T cells (Treg) in the spleen. RESULTS: Compared with the control group, mechanical pain and heat pain thresholds were significantly reduced(P<0.000 1), while paw thickness, expressions of IL-1ß, TNF-α, and NLRP3 in the paw, and positive expression of M1 macrophage marker iNOS in the paw, the proportions of macrophages and neutrophils in the spleen were significantly increased (P<0.000 1, P<0.001) in the model group. Compared with the model group, mechanical pain threshold and heat pain thresholds, CD206 positive expression in the paw, and Treg cell proportion in spleen were significantly increased (P<0.01), while paw thickness, the expressions of IL-1ß, TNF-α and NLRP3 in the paw, as well as the positive expression of M1 macrophage marker iNOS in the paw, the proportions of macrophages and neutrophils in the spleen were significantly reduced (P<0.001, P<0.01, P<0.05)in mice of the EA group after intervention. CONCLUSIONS: EA may alleviate pain and swelling in mice with chronic inflammatory pain by regulating the numbers of macrophages, neutrophils, and Treg cells, as well as promoting M2 polarization of local macrophages and inhibiting the release of pro-inflammatory cytokines.
Assuntos
Dor Crônica , Eletroacupuntura , Camundongos , Animais , Fator de Necrose Tumoral alfa/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR , Camundongos Endogâmicos C57BL , Dor Crônica/genética , Dor Crônica/terapia , Interleucina-1beta , Adjuvante de FreundRESUMO
BACKGROUND: Innate immune memory of macrophages is closely linked to histone modifications. While various studies have demonstrated that the polysaccharide of Asparagus cochinchinensis (Lour.) Merr (ACMP), extracted through alcohol-alkali extraction, enhances macrophages' non-specific immune function; no literature currently addresses whether ACMP's regulatory effect is related to innate immune memory and histone modification. PURPOSE: This study aims to investigate if ACMP induces innate immune memory emergence in macrophages via pattern recognition receptor (PRR). STUDY DESIGN: After co-incubating different doses of ACMP with RAW264.7 cells and BMDM cells, we observed changes in signaling pathways related to PRR and assessed the presence of innate immune memory phenomenon in the cells. METHODS: We observed the morphological characteristics of the ACMP using a scanning electron microscope, infrared spectrum, and HPLC pre-column derivatization method. We used q-PCR, Western blot, RNA-seq, and CUT&Tag-seq methods to examine ACMP's regulation of macrophage immune response and innate immune memory and explored its specific mechanism. RESULTS: ACMP, primarily composed of Man, GlcN, Rha, Fuc, GalA, Xyl, Glc, Gal, Ara, and, exhibited a molar ratio of each monosaccharide (1.41: 0.35: 0.49: 0.18: 1.00: 97.12: 0.36: 3.58: 1.14). ACMP regulated immunological function in macrophages through the TLR4-MAPK-JNK/p38/ERK pathway. ACMP induced elevated levels of chromosomal H3K4me1, enhancing TNF-α, IL-1ß, and other genes' responsiveness, allowing macrophages to develop innate immune memory to ACMP stimulation. CONCLUSION: This study first time demonstrates that ACMP regulates immunological function through the TLR4-MAPK-JNK/ERK/p38 signaling pathway, distinct from prior reports. ACMP induces innate immune memory in macrophages in response to its immune stimulation by promoting increased H3K4me1 on chromosomes. This mechanism may be crucial in how plant polysaccharides regulate macrophages and the body's immune function.