Thymic Stromal Lymphopoietin Promotes Fibrosis and Activates Mitogen-Activated Protein Kinases in MRC-5 Cells

Overexpression of miR-142-5p inhibits the progression of nonalcoholic steatohepatitis by targeting TSLP and inhibiting JAK-STAT signaling pathway

This study aimed to figure out the underlying mechanism of miR-142-5p in the non-alcoholic steatohepatitis (NASH). Bioinformatics, luciferase assay and Western blot were performed. The NASH mouse model was established through feeding a high fat diet (HFD). Relative expressions of miR-142-5p, thymic stromal lymphopoietin (TSLP), inflammatory factors were detected by qRT-PCR. The injury level of liver was assessed via measurement of serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST). H&E staining and Masson's trichrome staining examine the liver fatty degeneration and fibrosis. MiR-142-5p and TSLP were differentially expressed and JAK-STAT signaling pathway was activated in the NASH group. Luciferase assay identified that TSLP was the downstream target of miR-142-5p. Through overexpression of miR-142-5p, ALT and AST in serum were inhibited, pro-inflammatory factors, liver fatty degeneration and fibrosis in liver tissues were decreased, while anti-inflammatory factors were increased. Overexpression of TSLP and JAK-STAT signaling pathway activation could reverse the effects of miR-142-5p on NASH. Taken together, overexpression of miR-142-5p could attenuate NASH progression via inhibiting TSLP and JAK-STAT pathway. MiR-142-5p might be a novel latent target for NASH therapy.

The role of cancer-associated fibroblast MRC-5 in pancreatic cancer

Background: Our previous study showed that cancer-associated fibroblast MRC-5 promoted hepatocellular carcinoma progression by enhancing migration and invasion capability. However, few studies have explored the role of MRC-5 in pancreatic cancer (PC). In this study, we examined the exact role and associated mechanisms of MRC-5. Methods: The conditioned media for MRC-5 was used to culture PC cell lines SW1990 and PANC-1. Cell proliferation was compared based on colony formation assays of PC cells in normal media and of PC cells cultured with conditioned media of MRC-5. Cell migration and invasion were assayed by transwell chambers. The expression of EMT-related proteins and apoptosis-related proteins was evaluated using Western blot. And confocal microscopy was used to further detect the expression of EMT-related proteins. qRT-PCR was used to confirm the expression changes of related genes at the mRNA level. We also used flow cytometry to examine the cell cycle, apoptotic rate, and expression of CD3, CD4, CD14, CD25, CD45, CD61, CD90, TLR1, and TLR4. Results: MRC-5 repressed the colony formation ability of PC cells and significantly inhibited cell migration and invasion potential. MRC-5 induced S-phase cell cycle arrest but did not augment the apoptotic effects in PC cells. We hypothesized that the weakened malignant biological behavior of PC cells was correlated with MRC-5-induced altered expression of the cancer stem cell marker CD90; the immune-related cell surface molecules CD14, CD25, TLR4, and TLR1; and cell polarity complexes Par, Scribble, and Crumbs. Conclusion: MRC-5 limits the malignant activities of PC cells by suppressing cancer stem cell expansion, remolding epithelial polarity, and blocking the protumoral cascade reaction coupled to TLR4, TLR1, CD14, and CD25.

Type 2 immunity in tissue repair and fibrosis

Type 2 immunity is characterized by the production of IL-4, IL-5, IL-9 and IL-13, and this immune response is commonly observed in tissues during allergic inflammation or infection with helminth parasites. However, many of the key cell types associated with type 2 immune responses - including T helper 2 cells, eosinophils, mast cells, basophils, type 2 innate lymphoid cells and IL-4- and IL-13-activated macrophages - also regulate tissue repair following injury. Indeed, these cell populations engage in crucial protective activity by reducing tissue inflammation and activating important tissue-regenerative mechanisms. Nevertheless, when type 2 cytokine-mediated repair processes become chronic, over-exuberant or dysregulated, they can also contribute to the development of pathological fibrosis in many different organ systems. In this Review, we discuss the mechanisms by which type 2 immunity contributes to tissue regeneration and fibrosis following injury.