Transforming growth factor-β1 (TGF-β1) alters the fibroblast phenotype by promoting transdifferentiation into myofibroblasts, which exhibit the ability to promote collagen synthesis and extracellular matrix (ECM) deposition, thereby playing a significant role in the pathology of silicosis. In this study, we investigated the regulatory mechanisms involved in myofibroblast transdifferentiation. Two-dimensional gel electrophoresis showed that Rho GDP-dissociation inhibitor α (RhoGDIα) was upregulated following myofibroblast transdifferentiation stimulated by TGF-β1. We hypothesised that RhoGDIα may induce myofibroblast transdifferentiation and thus result in silicosis. Accordingly, the biological significance of RhoGDIα in cell proliferation and apoptosis was investigated by deletion of RhoGDIα in MRC-5 cells. In addition, a mechanistic study showed that fasudil, an inhibitor of the RhoA/Rho kinase (ROCK) signalling pathway, reduced the levels of RhoGDIα, RhoA, and phospho-myosin phosphatase （phospho-MYPT） in MRC-5 cells and silicosis model rats. Knockdown of RhoGDIα inhibited myofibroblast transdifferentiation and collagen deposition through RhoGDIα/RhoA/ROCK signalling in silicosis model mice. Overall, downregulation of RhoGDIα may significantly promote cell apoptosis and inhibit cell growth, resulting in reversal of myofibroblast transdifferentiation by RhoA/ROCK in vitro and in vivo. These data will facilitate further exploration of the potential use of RhoGDIα as a target for silicosis therapy.

Parkinson's disease (PD) is a common neurodegenerative disease. Here, the purpose of the study was to explore the function of long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) in PD and its underlying mechanism. An in vivo 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-hydrochloride (MPTP)-induced mouse model of PD was generated and the SH-SY5Y cells were treated with MPP + to induce neuronal damage in vitro. Quantitative real-time polymerase chain reaction (QRT-PCR) and Western blot were used to detect the expression of HOTAIR, miR-221-3p, α-synuclein and apoptosis-related genes. MTT, flow cytometry and TUNEL assay was used to detect cell viability and apoptosis, respectively. The levels of inflammatory cytokines TNF-α,IL-1β and IL-6 were detected by ELISA assay. The levels of lactate dehydrogenase (LDH), reactive oxygen species (ROS), and superoxide dismutase (SOD) were determined using the appropriate assay kits. The interactions between miR-221-3p and HOTAIR or α-synuclein were determined by dual luciferase assay and RNA binding protein immunoprecipitation (RIP). Co-localization of HOTAIR and miR-221-3p was also proved by immunofluorescence staining. The results showed that HOTAIR was highly expressed, while miR-221-3p expression was decreased in PD model in vivo and in vitro. In SH-SY5Y cells treated with MPP+, the knockdown of HOTAIR increased cell viability and reduced cell apoptosis, the secretion of inflammatory cytokines and oxidative stress reaction, while HOTAIR overexpression led to opposite effects. Furthermore, HOTAIR sponged miR-221-3p which directly targeted α-synuclein and thus regulated the expression of α-synuclein. Meanwhile, inhibiting miR-221-3p could partially reverse the neuroprotective effects of HOTAIR knockdown. In conclusion, HOTAIR attenuated the injury of SH-SY5Y cells induced by MPP+ via miR-221-3p/α-synuclein axis, suggesting the potential therapeutic value of HOTAIR in PD.

Occupational exposure to silica dust particles was the major cause of pulmonary fibrosis, and many miRNAs have been demonstrated to regulate target mRNAs in silicosis. In the present study, we found that a decreasing level of miR-411-3p in silicosis rats and lung fibroblasts induced by TGF-β1. Enlargement of miR-411-3p could inhibit the cell proliferation and migration in lung fibroblasts with TGF-β1 treatment and attenuate lung fibrosis in silicotic mice. In addition, a mechanistic study showed that miR-411-3p exert its inhibitory effect on Smad ubiquitination regulatory factor 2 (Smurf2) expression and decrease ubiquitination degradation of Smad7 regulated by smurf2, result in blocking of TGF-β/Smad signaling. We proposed that increased expression of miR-411-3p abrogates silicosis by blocking activation of TGF-β/Smad signaling through decreasing ubiquitination degradation effect of smurf2 on Smad7.

Ureteropelvic junction obstruction (UPJO) is a common renal obstructive disorder, but its pathogenic mechanisms remain largely unclear. We aimed to investigate the potential involvement of the renin-angiotensin system in congenital UPJO pathogenesis.