RÉSUMÉ
ObjectiveTo observe the effect of Youguiwan on the leptin/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in the lung tissue of the rat model of chronic obstructive pulmonary disease (COPD) due to kidney-Yang deficiency. MethodForty rats were modeled for COPD with the syndrome of kidney-Yang deficiency by intratracheal instillation of lipopolysaccharide on day 1 and day 14 and continuous fumigation for 6 weeks, during which hydrocortisone was injected intramuscularly at an interval of 3 days. The modeled rats were randomized into model, high- (11.7 g·kg-1), medium- (5.85 g·kg-1), and low-dose (2.93 g·kg-1) Youguiwan, and aminophylline (0.054 g·kg-1) group. In addition, 8 SD rats were set as the blank group. After the completion of modeling, the rats in each group were administrated with the corresponding drug by gavage for 28 consecutive days. After the last administration, samples were collected. A lung function analyzer was used to evaluate the lung function of rats. Enzyme-linked immunosorbent assay was employed to measure the levels of interleukin-17A (IL-17A), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the bronchoalveolar lavage fluid (BALF). Hematoxylin-eosin staining was employed to observe the pathological changes in the lung tissue, and Masson staining was employed to observe the deposition of blue collagen fibers around bronchi in the lung tissue and calculate the inflammation score. The immunofluorescence assay was employed to measure the protein content of collagen type Ⅰ (ColⅠ) and α-smooth muscle actin (α-SMA) in the bronchi. The protein and mRNA levels of leptin, IL-17A, JAK2, and STAT3 in the lung tissue were determined by Western blot and real-time fluorescence quantitative polymerase chain reaction, respectively. ResultCompared with the blank group, the model group showed decreased lung function (P<0.01), elevated levels of IL-6, IL-17A, and TNF-α in the BALF (P<0.01), and increased lung inflammation score, deposition of subcutaneous collagen fibers in the airway, and ColⅠ and α-SMA proteins (P<0.01). Furthermore, the modeling up-regulated the proteins and mRNA levels of leptin, IL-17A, JAK2, and STAT3 in the lung tissue (P<0.01) and enhanced the phosphorylation of JAK2 and STAT3 (P<0.01). Compared with the model group, high- and medium-dose Youguiwan improved the lung function, decreased the inflammation score, reduced collagen fiber deposition and ColⅠ and α-SMA proteins, lowered the levels of IL-6, IL-17A, and TNF-α in the BALF, down-regulated the mRNA and protein levels of leptin, JAK2, STAT3, and IL-17A, and weakened the phosphorylation of JAK2 and STAT3 (P<0.05, P<0.01). The aminophylline group had higher IL-17A and TNF-α levels than the high-dose Youguiwan group, lower IL-17A level than the medium and low-dose Youguiwan groups, and lower TNF-α level than the low-dose Youguiwan group. Compared with the aminophylline group, the high- and medium-dose Youguiwan groups showed reduced deposition of collagen fibers and protein levels of ColⅠ and α-SMA around the bronchi in the lung tissue (P<0.05, P<0.01), decreased inflammation score, and down-regulated protein and mRNA levels of leptin, JAK2, STAT3, and IL-17A in the lung tissue. ConclusionYouguiwan can prevent airway remodeling by inhibiting IL-17A to reduce inflammation and collagen deposition in COPD rats, which may be related to the inhibition of the leptin/JAK2/STAT3 signaling pathway.
RÉSUMÉ
Objective:To investigate the therapeutic effect of polydatin on ulcerative colitis (UC) in mice and its regulation of protein kinase C<italic>θ</italic>(PKC<italic>θ</italic>)/signal transducer and activator of transcription 3(STAT3) signaling on T helper cell 17(Th17) and its mechanism in the treatment of UC. Method:The 32 male C57BL/6 mice were randomly divided into normal group, model group, polydatin group (0.045 g·kg<sup>-1</sup>) and sulfasalazine group (0.5 g·kg<sup>-1</sup>). The UC model was established by giving 3% dextran sodium sulfate (DSS) solution to free drinking water in mice. Polydatin and sulfasalazine groups were given by gavage 0.5 h before modeling for 7 days. The normal group and model group were given the same amount of normal saline. After the last administration, the colonic tissue was taken and hematoxylin-eosin (HE) was used to observe the pathological changes of colonic tissue. Flow cytometry was used to detect the proportion of Th17 in the lamina propria of colonic mucosa. The expression of interleukin-17A (IL-17A) in serum was detected by enzyme-linked immunosorbent assay (ELISA). Polydatin was added to CD4<sup>+ </sup>T cells purified from spleen of C57BL/6 mice by magnetic-activated cell sorting (MACS) under the stimulation of cell stimulation cocktail <italic>in vitro </italic>in order to detect its impact on PKC<italic>θ</italic> and STAT3 phosphorylation. Result:Compared with normal group, the body weight was significantly decreased, and disease activity index (DAI) scores of the model group was significantly increased (<italic>P</italic><0.01), the colonic mucosal epithelium was damaged and inflammatory cells infiltration in the mucosa and submucosa was obvious, the proportion of Th17 in the lamina propria of colonic mucosa was significantly increased (<italic>P</italic><0.01), and the content of serum IL-17A was significantly increased (<italic>P</italic><0.01). Compared with the model group, the weight and DAI score of polydatin and sulfasalazine groups were significantly improved (<italic>P</italic><0.01), the degree of colon tissue damage was significantly improved, the proportion of Th17 in colon mucosa lamina propria was significantly decreased (<italic>P</italic><0.01), and the content of IL-17A in serum was significantly decreased (<italic>P</italic><0.01). <italic>In vitro</italic> experiments showed that polydatin could significantly inhibit the phosphorylation of PKC<italic>θ</italic> and STAT3 in Th17 (<italic>P</italic><0.01) as well as IL-17A secretion. Conclusion:Polydatin can improve the ulcerative colitis in mice via inhibiting the phosphorylation of PKC<italic>θ</italic> and STAT3 to preclude IL-17A secreting in Th17.
RÉSUMÉ
This study was conducted to determine whether CD4 T cell responses to citrullinated fibrinogen occur in patients with rheumatoid arthritis (RA), especially in HLA-DR4-positive subjects. Whole peripheral blood mononuclear cells (PBMCs) of RA patients and control subjects were stimulated with citrullinated fibrinogen peptides, and T-cell production of proliferation and proinflammatory cytokines, such as interferon-gamma(IFN-gamma) and interleukin-17A (IL-17A), were measured. In addition, CD4 T cells from RA patients were stimulated with the citrullinated fibrinogen peptide, Fib-alpha R84Cit, identified as a DRB1*0401-restricted T cell epitope in HLA-DR4 transgenic mice, and the degree of T cell activation was examined similarly. No proliferative responses to the citrullinated fibrinogen peptides were observed in whole PBMCs or CD4 T cells from RA patients. Furthermore, no increased production of IFN-gamma or IL-17A was found in whole PBMCs or CD4 T cells stimulated with the citrullinated fibrinogen peptides, although these cells responded to recall antigen, a mixture of tetanus toxoid, purified protein derivative (PPD) from Mycobacterium tuberculosis, and Candida albicans. The results of this study indicate that anti-citrulline immunity in RA patients may be mediated by fibrinogen because there is no evidence of CD4 T cell-mediated immune responses to citrullinated fibrinogen peptides.