Effect and mechanism of acupressure at Zusanli on interstitial cell of Cajal cells in spleen-deficient rats based on the Keap1-Nrf2-ARE pathway
ZHANG Qi,MA Xin-long,ZHAO Na
Abstract:
Objective To explore the effects of acupressure at the Zusanli point (ST36) on interstitial cells of Cajal (ICC) in spleen-deficient rats and its molecular mechanisms via the Keap1-Nrf2-ARE pathway. Methods 40 SD rats were randomly divided into control group, model group, acupoint group and inhibitor group, with 10 rats in each group. The latter two groups received acupoint intervention for a total of two weeks, while the model and control group were merely fixated in the same way without any treatment. Gastric antrum tissues were analyzed by HE staining and immunofluorescence. The levels of cytoplasmic proteins (Keap1), HO-1, ANO1, and Nrf2 protein and mRNA expression were measured. The expression of mechano growth factor (MGF) in the lower legs muscle tissues was also assessed. Finally, ICC ultrastructure was observed using electron microscopy. Results Compared with the control group, the model group exhibited significant damage and edema in HE staining, with ANO1 protein and mRNA increased expression (P <0.01) and decreased expression of Keap1, Nrf2, and HO-1 proteins and mRNA. MGF protein and mRNA showed no significant differences (P > 0.05). The number of ICC cells decreased, and their morphology was damaged. In comparison with the model group, the acupoint group showed milder inflammation and edema in HE staining and lower ANO1 protein and mRNA expression (P < 0.01), and upregulated Keap1, Nrf2, HO-1, and MGF protein and mRNA levels. Electron microscopy revealed more ICC cells with less morphological damage. Compared to the acupoint group, the inhibitor group exhibited revealed severe tissue damage and edema in HE staining, higher ANO1 protein and mRNA expression, and lower Keap1, Nrf2, and HO-1 protein and mRNA levels. MGF protein remained stable (P > 0.05). Electron microscopy showed fewer ICC cells with more severe morphological damage. Conclusion Acupressure at ST36 can improve the gastric antrum tissue pathology and restore the damaged ICC cell ultrastructure in spleen-deficient rats. Activating MGF and upregulating the Nrf2 pathway to induce ICC cell proliferation and repair may be one of the mechanisms through which acupressure on Zusanli adjusts digestive function in spleen-deficient rats.
