Bone marrow mesenchymal stem cell-derived exosomes alleviate skin fibrosis in systemic sclerosis by inhibiting the IL-33/ST2 axis via the delivery of microRNA-214.

Interleukin (IL)- 33 is a tissue-derive proinflammatory cytokine that promotes fibrosis in systemic sclerosis (SSc). microRNA (miR)- 214 expression has been elaborated to be downregulated in SSc patients and exert anti-fibrotic and anti-inflammatory effects. This study elucidates the role of bone marrow mesenchymal stem cell-derived exosome (BMSC-Exos)-delivered miR-214 in SSc and the relationship between this miR and IL-33/ST2 axis. SSc clinical samples were obtained to evaluate levels of miR-214, IL-33, and ST2. Primary fibroblasts and BMSC-Exos were extracted, followed by the co-culture of PKH6-labeled BMSC-Exos and fibroblasts. Subsequently, Exos extracted from miR-214 inhibitor-transfected BMSCs were co-cultured with TGF-ß1-stimulated fibroblasts, after which the expression of fibrotic markers, miR-214, IL-33, and ST2, as well as fibroblast proliferation and migration, was determined. A skin fibrosis mouse model was induced with bleomycin (BLM) and treated with BMSC-Exos. Collagen fiber accumulation, collagen content, α-SMA expression, and IL-33 and ST2 levels were examined in BLM-treated or IL-33-knockout mice. IL-33 and ST2 were upregulated and miR-214 was downregulated in SSc patients. Mechanistically, miR-214 targeted IL-33 and blocked the IL-33/ST2 axis. BMSC-Exos delivering miR-214 inhibitor augmented proliferation, migration, and fibrotic gene expression in TGF-ß1-stimulated fibroblasts. Similarly, IL-33 induced migration, proliferation, and fibrotic gene expression in fibroblasts via ST2. In BLM-treated mice, IL-33 knockout suppressed skin fibrosis, and BMSC-Exos delivered miR-214 to suppress the IL-33/ST2 axis, thus mitigating skin fibrosis. Conclusively, BMSC-Exos alleviate skin fibrosis through the blockade of the IL-33/ST2 axis by delivering miR-214.

MiR-144-3p induced by SP1 promotes IL-1ß-induced pyroptosis in chondrocytes via PTEN/PINK1/Parkin axis.

Rheumatoid arthritis (RA) often leads to functional disabilities and deformities. MiRNA plays a vital role in cell pyroptosis. Nevertheless, the function and underlying mechanism of miR-144-3p in pyroptosis during the progression of RA remains unclear. In this study, N1511 cells were stimulated with IL-1ß to construct a RA model. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was performed to assess the cell viability. Cell pyroptosis was detected by flow cytometry. The levels of inflammatory cytokines (TNF-α, IL-6, and IL-18) were assessed by enzyme-linked immunosorbent assay (ELISA). The relationship among specific protein 1 (SP1), microRNA-144-3p (miR-144-3p), and phosphatase and tensin homolog (PTEN) was explored by dual-luciferase reporter assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP), respectively. The level of miR-144-3p in N1511 cells was upregulated by IL-1ß. MiR-144-3p knockdown inhibited IL-1ß-induced pyroptosis in N1511 cells, and the expressions of NOD-like receptor family pyrin domain containing 3 (NLRP3), Cleaved caspase-1, Gasdermin D (GSDMD), and Cleaved caspase-3 in IL-1ß-stimulated N1511 cells were increased. The levels of inflammatory cytokines in N1511 cells were increased by IL-1ß, which were restored by miR-144-3p knockdown. MiR-144-3p knockdown abolished IL-1ß-induced inactivation of putative kinase 1 (PINK1)/Parkin RBR E3 ubiquitin-protein (Parkin) signalling. Moreover, transcription factor SP1 could upregulate miR-144-3p expression and miR-144-3p negatively regulated PTEN expression. In summary, MiR-144-3p induced by SP1 could promote IL-1ß-induced chondrocyte pyroptosis via inhibiting PTEN expression and suppressing the activation of PINK1/Parkin signalling, which provided a new strategy against RA.

miR-144-3p aggravated cartilage injury in rheumatoid arthritis by regulating BMP2/PI3K/Akt axis.

OBJECTIVES: Present study aimed to illustrate the role of miR-144-3p in rheumatoid arthritis (RA). METHODS: N1511 chondrocytes were stimulated by interleukin (IL)-1ß to mimic RA injury model in vitro. Rats were subjected to injection of type II collagen to establish an in vivo RA model, and the arthritis index score was calculated. Cell viability was determined by Cell Counting Kit-8. The expression of cartilage extracellular matrix proteins (collagen II and aggrecan) and matrix metalloproteinase protein were determined by quantitative real-time polymerase chain reaction and western blots. Cell apoptosis was measured by flow cytometry. Enzyme-linked immunosorbent assay was applied to test the secretion of pro-inflammatory cytokines (IL-1ß and tumour necrosis factor-α). Tissue injury and apoptosis were detected by haematoxylin-eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling assay staining. Interaction of miR-144-3p and bone morphogenetic protein 2 (BMP2) was verified by dual-luciferase assay. RESULTS: miR-144-3p was dramatically increased in IL-1ß-induced N1511 cells. miR-144-3p depletion elevated cell viability, suppressed apoptosis, pro-inflammatory cytokine releasing, and extracellular matrix loss in IL-1ß-induced N1511 cells. Moreover, miR-144-3p targeted BMP2 to modulate its expression negatively. Activation of phosphatidylinositol 3-kinase (PI3K)/Akt signalling compromised inhibition of BMP2 induced aggravated N1511 cell injury with IL-1ß stimulation. Inhibition of miR-144-3p alleviated cartilage injury and inflammatory in RA rats. CONCLUSION: Collectively, miR-144-3p could aggravate chondrocyte injury inflammatory response in RA via BMP2/PI3K/Akt axis.

Clinical features of pulmonary cryptococcosis in thin-section CT in immunocompetent and non-AIDS immunocompromised patients.

RATIONAL AND OBJECTIVES: To compare thin-section computed tomography (CT) features of pulmonary cryptococcosis (PC) in immunocompetent and non-AIDS immunocompromised patients. MATERIALS AND METHODS: We retrospectively reviewed CT findings of 18 immunocompetent and 24 non-AIDS immunocompromised patients with clinically proven PC. Different patterns of pulmonary abnormalities between the two groups of patients were compared by Fisher's exact test. RESULTS: Pulmonary nodules were present in 37 of the 42 patients. Masses were detected in 16 patients and consolidation in 9. There were 12 patients with a solitary nodule or mass. Masses were associated with nodules in 12 patients. Consolidation was associated with nodules/masses in nine patients. The nodules/masses were associated with cavitations in 13 patients. Margination of nodules/masses was well defined in nine patients and ill-defined in 33. The abnormalities were predominantly distributed in the peripheral region of the lung (n = 29, 69.0%). The presence of cavitations in nodules/masses was significantly more frequent in non-AIDS immunocompromised than in immunocompetent patients (P = 0.001). CONCLUSIONS: The most common thin-section CT feature of PC was pulmonary nodules/masses, which were ill-defined and located peripherally. Cavitations within nodules/masses were more commonly found in non-AIDS immunocompromised patients. PC should be considered in the differential diagnosis of pulmonary nodules/masses.