RESUMEN
Aim To investigate the role of TGF-β/Smad signaling pathway in rheumatoid arthritis (RA) - associated postinterstitial pulmonary fibrosis in mice. Methods The mouse model of RA was constructed by subcutaneous administration of complete Freund's adjuvant (CFA) and chicken II collagen (Col-II) to the tail root of mice. The blank group was given the same amount of distilled water, and the control group was given the same amount of glacial acetic acid (solvent). The degree of toe swelling (joint swelling degree and arthritis index) was monitored to evaluate the mouse modeling. The pathological changes of mouse lung tissues were observed by HE and Masson staining. The expression of TGF-β in lung tissues were observed by immunohistochemical staining. The level of hydroxyproline in lung tissues was measured by chemiluminescence method. The expressions of Smad2, Smad3 and phosphorylated p-Smad2 and phosphorylated p-Smad3 in lung tissues were detected by Western blot. Results Compared with blank group and solvent group, the joint swelling and arthritis index of model group significantly increased. Twenty-one days after administration, HE staining showed inflammatory changes in lung interstitium of the model group, Masson staining showed collagen fiber deposition and obvious fibrosis in lung interstitium of the model group, and immunohistochemical staining showed that the expression of TGF-β in cytoplasm of lung interstitial cells of the model group increased, which was brown and yellow. Meanwhile, hydroxyproline was significantly raised in lung tissue homogenate of the model group. Further WB analysis showed that compared with blank group and solvent group, the expression of p-Smad2 and pSmad3 in lung tissues of the model group was significantly up-regulated (P < 0. 05, P < 0. 01). Conclusions RA can give rise to pulmonary fibrosis, and the expressions of p-Smad2 and p-Smad3 are up-regulated, which is be pivotal in pulmonary fibrosis and RA-related post-interstitial pulmonary fibrosis.
RESUMEN
Aim To investigate the possible mechanism of paeonol inhibiting the inflammatory response of fibroblast synovial cells (RA-FLSS) in rheumatoid arthritis. Methods CCK-8 assay was used to detect Paeonol's inhibitory level on the abnormal proliferation of arthritis human fibroblast synovial cells (RA-FLSs). The levels of endoplasmic reticulum stress-related proteins MANF and ATF6 were detected by Western blot. Cell localization of transcription factor p65 and Mesencephalic Astrocyte Derived Neurotrophic Factor (MANF) was detected by immunofluorescence. RT-qPCR detected the changes of p65 target genes. Results Paeonol could significantly inhibit the abnormal proliferation of RA-FLSS cells. Paeonol activates ATF6 and increases the expression of MANF. Paeonol promoted the nuclear transfer of MANF protein and inhibited the transcriptional activity of p65. Conclusion Paeonol promotes the expression of MANF and nuclear transfer through the endoplasmic reticulum stress pathway and affects the progression of RA by inhibiting the transcriptional activity of p65.