Objective To investigate the expression of mitochondrial autophagy-associated protein PINK1 and Parkin in parotid pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma(CA-EX-PA). Methods The expression of PINK1 and Parkin were detected by immunohistochemistry in 24 cases of normal parotid gland tissues, 32 cases of PA tissues and 42 cases of CA-EX-PA tissues. The correlations of PINK1 and Parkin expression with the clinicopathologic characteristics of CA-EX-PA patients were analyzed. Results The positive rates of PINK1 in normal parotid gland, PA and CA-EX-PA tissues were 100%, 91% and 67% respectively; and those of Parkin were 100%, 88% and 52% respectively. The expression rates of PINK1 and Parkin in PA and CA-EX-PA tissues were significantly lower than those in normal tissues (P < 0.05). The expression of PINK1 and Parkin protein were positively correlated in CA-EX-PA tissues (r=0.877, P < 0.01). In CA-EX-PA tissues, the expression of PINK1 and Parkin were associated with tumor invasion, lymph node metastasis and TNM stage (P < 0.05). Conclusion The expression of PINK1 and Parkin are decreased in PA and CA-EX-PA tissues. The decrease of mitochondrial autophagy activity might play important roles in the development, invasion and metastasis of parotid gland tumors.

BACKGROUND:Human placental mesenchymal stem cells have been shown to be effective in inhibiting the development of pulmonary fibrosis,but the underlying mechanisms remain unclear. OBJECTIVE:To investigate the therapeutic effect and related mechanism of human placental mesenchymal stem cells on silica-induced pulmonary fibrosis in human embryonic lung fibroblasts(MRC-5). METHODS:CCK-8 assay was used to detect the effects of different mass concentrations of silica on the proliferation of MRC-5 at different time points.Immunofluorescence staining was used to screen out the best stimulating mass concentration and time of silica for subsequent experiments.MRC-5 cells were divided into blank group,silica group,and silica + human placental mesenchymal stem cell group.In the blank group,cells were not treated.In the silica group,MRC-5 cells were stimulated with 100 μg/mL silica for 48 hours.In the silica + human placental mesenchymal stem cell group,MRC-5 cells were stimulated with 100 μg/mL silica for 48 hours and then co-cultured with human placental mesenchymal stem cells for 24 hours.Immunofluorescence staining was used to detect the expression of α-smooth muscle actin and collagen type I in cells of each group.Western blot assay was used to detect the expressions of pulmonary fibrosis-related proteins and TGF-β1/Smad 3 signaling pathway-related proteins in cells of each group. RESULTS AND CONCLUSION:(1)CCK-8 assay results suggested that 100 μg/mL silica was the best mass concentration and time to stimulate MRC-5 cells for 48 hours.(2)Immunofluorescence staining results showed that the expression of α-smooth muscle actin and collagen type I in the silica + human placental mesenchymal stem cell group was significantly lower than that in the silica group.(3)Western blot assay results showed that compared with the silica group,the protein expression levels of α-smooth muscle actin,collagen type I,N-cadherin,fibronectin,transforming growth factor-β1,p-Smad3,and Smad3 in the silica + human placental mesenchymal stem cell group were decreased,and the expression of E-cadherin was increased.The difference was statistically significant(P<0.05).(4)The results showed that human placental mesenchymal stem cells had a significant therapeutic effect on silica-induced pulmonary fibrosis.Human placental mesenchymal stem cells can inhibit the development of pulmonary fibrosis by regulating transforming growth factor-β1/Smad3 signaling pathway.

Objective:To analyze whether there are differences and related influencing factors in liver injury associated with different strains of 2019-nCoV/SARS-CoV-2 infection.Methods:Data of epidemiology, clinical symptoms, laboratory tests, and treatment outcomes of patients with COVID-19 infection confirmed with Alpha and Delta virus strain in Zhejiang Province were retrospectively collected. Statistical analysis was performed using independent samples t-test or Mann-Whitney U test, χ2 test or Fisher's exact test, and logistic regression analysis. Results:A total of 788 and 381 cases with Alpha and Delta virus strain were included. Vaccination ratio was 0% in Alpha and 85.30% in Delta group ( P<0.001), The proportion of patients with fever (80.71% vs. 40.94%, P<0.001) was significantly higher in Alpha than Delta strain group. The proportion of critical ill patients was significantly higher in Delta group (9.90% vs. 1.57%, respectively, P<0.001). The virus negative conversion time was significantly longer in Delta than Alpha group (22 d vs. 11 d, P<0.001), but the incidence of liver injury was significantly higher in Alpha than Delta group (20.05% vs. 13.91%, P=0.011). Univariate analysis showed that Alpha virus strain infection, male sex, body mass index, chronic liver disease, fever, diarrhea, shortness of breath, severe/critical illness, elevated creatine kinase (CK), elevated international normalized ratio (INR) and an elevated neutrophil/lymphocyte ratio was significantly associated with an increased risk of liver injury occurrence, and in patients with pharyngeal pain the risk of liver injury occurrence was significantly reduced. Multivariate analysis showed that shortness of breath [ OR, 2.667 ( CI: 1.389-5.122); P=0.003], increased CK [ OR, 2.544 ( CI: 1.414-4.576); P=0.002] and increased INR [OR, 1.721] ( CI: 1.074-2.758); P=0.024] was significantly associated with an increased risk of liver injury occurrence, and in patients with pharyngeal pain the risk of liver injury occurrence was significantly reduced [ OR, 0.424 ( CI: 0.254-0.709); P=0.001]. Conclusion:Although the virulence of the Delta is stronger than Alpha strain, most patients infected with Delta strain vaccinated against COVID-19 in Zhejiang province had milder clinical symptoms and a lower incidence and degree of liver injury. Notably, the infection risk even remains after vaccination; however, symptoms and the incidence of severe and critical illness can be significantly reduced.