Kuijieling decoction suppresses NLRP3-Mediated pyroptosis to alleviate inflammation and experimental colitis in vivo and in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Ulcerative colitis (UC) is an autoimmune disease. Although the mortality rate of UC is not very high, it has a considerable morbidity rate and an unsatisfactory cure rate. Without effective treatment, UC is likely to develop into colon cancer. Kuijieling (KJL) is an effective empirical formula to treat UC in the clinical setting, and it has been proven to have curative effects against UC. AIM OF THE STUDY: In a previous study, we demonstrated that KJL could suppress NOD-like receptor protein 3 (NLRP3) to reduce inflammatory cytokines and alleviate UC. In this study, we investigated the mechanism of KJL in more detail, from the perspective of pyroptosis. MATERIALS AND METHODS: We established a dextran sulfate sodium-induced UC mouse model and RAW264.7 cells to measure different indicators with different experimental methods. The efficiency of KJL was evaluated by measuring the length and unit weight of mouse colons, and assessment of pathological injury was performed using HE staining. We detected different expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, gasdermin-D C-terminal domain (GSDMD-C), gasdermin-D N-terminal domain (GSDMD-N), IL-1ß, and IL-18 in colon tissues and cells using RT-qPCR and western blotting. Immunohistochemistry was used for tissues and immunofluorescence for cells to confirm protein expression. IL-1ß and IL-18 were measured with enzyme-linked immunosorbent assay in serum, tissue, and cell culture supernatant. MiR-223 was detected using RT-qPCR. RESULTS: After administration of KJL suspension, colon damage in KJL groups was milder than in model groups. ASC, caspase-1, IL-1ß, and IL-18 mRNA levels in colon tissue were decreased to different degrees in the KJL groups. Protein expression of NLRP3, caspase-1, GSDMD-N, IL-1ß, and IL-18 in vivo decreased significantly in the KJL groups. In addition, Mir-223 level decreased in colon tissue of the KJL groups. In vitro, NLRP3, ASC, caspase-1, GSDMD-N, IL-1ß, and IL-18 levels decreased to varying degrees, at both mRNA and protein levels. Mir-223 was lower in the KJL groups than in the model group. Furthermore, KJL was shown to regulate the level of miR-223, which returned to normal after its expression was inhibited or promoted, and the levels of associated indicators also returned to normal after transfection. CONCLUSIONS: KJL is able to inhibit pyroptosis to alleviate UC, but these suppression effects were not mediated through miR-223 regulation.

Kuijieling-Containing Serum Regulates Th17 and Treg Cell Differentiation by Inhibiting STAT3 Signaling In Vitro.

OBJECT: To investigate the effect of Kuijieling (KJL) on the balance between T helper 17 (Th17) and regulatory T (Treg) cells in peripheral blood mononuclear cells (PBMC) in vitro and explore the underlying mechanism. MATERIALS AND METHODS: PBMCs isolated from rats were stimulated with transforming growth factor-ß, interleukin (IL)-6, and IL-23 to induce the imbalance of Th17 and Treg cells and were treated with 10, 5, or 2.5% KJL-containing serum. The proportion of Th17 or Treg cells in CD4+ T cells was analyzed by flow cytometry, the concentrations of IL-17, IL-21, and IL-10 were assayed by ELISA, mRNA expressions of retinoic acid-related orphan receptor γt (RORγt), forkhead box protein 3 (Foxp3), and signal transducer and activator of transcription 3 (STAT3) were quantified by PCR, and phosphorylated STAT3 (p-STAT3) was analyzed by flow cytometry. RESULTS: KJL-containing serum decreased the proportion of Th17 cells and increased the proportion of Treg cells in CD4+ T cells, decreased the concentration of IL-17 and IL-21, enhanced the level of IL-10 in the cell culture supernatant, promoted the expression of Foxp3, and inhibited the levels of RORγt, STAT3, and p-STAT3. CONCLUSION: KJL suppresses the STAT3 pathway to remedy the imbalance between Th17 and Treg cells.

Kuijieling regulates the differentiation of Treg and Th17 cells to ameliorate experimental colitis in rats.

BACKGROUND: Regulatory T (Treg) cells and T helper 17 (Th17) cells play crucial roles in ulcerative colitis (UC). Kuijieling (KJL) is an effective Chinese medicine formula for treating UC in clinic. Kuijieling has shown remedy effect on the imbalance between Treg and Th17 cells. This study aimed to further reveal the exact underlying mechanism of how Kuijieling regulates the differentiation of Treg and Th17 cells in the treatment of UC. METHODS: Colitis was induced by trinitrobenzene sulfonic acid in rats and treated by KJL. Pathological injury was evaluated by HE staining and pathological score. Transforming growth factor-ß1 (TGF-ß1), interleukin(IL)-2, IL-6, IL-10, IL-17, IL-23 and IL-21 in plasma were assayed by ELISA. Forkhead box P3 (Foxp3), signal transducer and activator of transcription (STAT) 5 expressed in colon mucosa were measured by western blot. Immunohistochemistry was employed for quantifying retinoic acid-related orphan receptor γt (RORγt) and STAT3 in colon. RT-PCR was used to analyze the expression of IL-2, IL-17, IL-23, IL-21 mRNA in colon. RESULTS: After the administration of KJL, pathological injury in colon mucosa was reduced and histological score was decreased, transforming growth factor-ß1 (TGF-ß1), interleukin(IL)-2, IL-10 in blood and Foxp3, STAT5, IL-2 in colon increased significantly, IL-6, IL-23, IL-17, IL-21 in blood and RORγt, STAT3, IL-23, IL-17, IL-21 in colon decreased. Our result showed that KJL regulates the related cytokines and transcription factors to promote Treg cells and suppress Th17 cells. CONCLUSION: KJL restores the balance between Treg and Th17 cells through regulating the differentiation of them, therefore contributes to the treatment of UC.