The Potential Role of Extracellular Vesicles in COVID-19 Treatment: Opportunity and Challenge.

SARS-CoV-2 infection has become an urgent public health concern worldwide, severely affecting our society and economy due to the long incubation time and high prevalence. People spare no effort on the rapid development of vaccine and treatment all over the world. Amongst the numerous ways of tackling this pandemic, some approaches using extracellular vesicles (EVs) are emerging. In this review, we summarize current prevalence and pathogenesis of COVID-19, involving the combination of SARS-CoV-2 and virus receptor ACE2, endothelial dysfunction and micro thrombosis, together with cytokine storm. We also discuss the ongoing EVs-based strategies for the treatment of COVID-19, including mesenchymal stem cell (MSC)-EVs, drug-EVs, vaccine-EVs, platelet-EVs, and others. This manuscript provides the foundation for the development of targeted drugs and vaccines for SARS-CoV-2 infections.

[Study on the relationship between microsatellite alterations of RASSF1A gene and the development of cervical carcinoma].

OBJECTIVE: To explore the relationship between microsatellite alterations of RASSF1A gene and the development of cervical carcinoma, and HPV16 infection. METHODS: Two sites of microsatellite polymorphism of RASSF1A gene were selected, we used polymerase chain reaction (PCR) technique to detect the LOH and MSI of cervical tissues, and to detect the infection state of HPV16. RESULTS: There were significant differences of LOH rates at the two sites between clinical stage and pathological grade (P < 0.05). Significant differences were noted between the cervical carcinomas with lymph node metastasis and those without lymph node metastasis in regard to their LOH and MSI at the two sites ( P < 0.05). The incidence of LOH of RASSF1A gene was higher in HPV16(+) than that in HPV16(-) ( P < 0.05). CONCLUSION: The change of RASSF1A gene is a relatively late event in cervical carcinomas. The detection of the LOH and MSI of RASSF1A gene might be helpful to the early diagnosis and the screening of cervical carcinoma. It might also be useful for predicting the prognosis of cervical carcinoma. Infection of HPV16 and LOH of RASSF1A gene had reacted together in the development of cervical carcinoma.

Effect of blockage of costimulatory signal on murine abortion-prone model.

BACKGROUND: Inhibition of the key costimulatory signals results in T cell anergy, indicating the alloantigen-specific immunologic unresponsiveness. In this study, the effect of blockage of costimulatory signal CD(86) on murine abortion-prone model was studied. METHODS: Thirty CBA/J female mice cohabitated with DBA/2 male or BALB/c male mice were investigated. CBA/J x DBA/2 matings were used as the abortion-prone model, and CBA/J x BALB/c matings were used as the normal pregnant model. The abortion-prone models were divided into experimental and control groups, and the normal pregnant models were set as a normal group (10 mice in each group). The mice in the experimental group were treated with anti-mouse CD(86) monoclonal antibody (mAb) (100 microg) on day 4.5 of gestation, while the controls received irrelevant-isotype matched rat IgG(2b). As for the normal group, nothing was given to the mice. The mice were killed on day 13.5 of gestation, embryo resorption rate and the expression of transforming growth factor beta(1) (TGF-beta(1)), plasminogen activator inhibitor 1 (PAI-1), and matrix metalloproteinase 9 (MMP-9) were detected. Then the data were analyzed by Chi-square test and Fisher's exact test. RESULTS: The embryo resorption rate in the experimental (8.2%) and normal groups (7.7%) was significantly lower than that of the control (23.5%, P < 0.05). No significant difference was detected between the experimental and normal groups (P > 0.05). The positive expression rates of TGF-beta(1) and PAI-1 proteins in the experimental and normal groups were significantly higher than those in the control group (P < 0.05). The positive expression rate of MMP-9 protein in the experimental and normal groups was significantly lower than that in the control group (P < 0.05). No significant difference in the positive expression rates of the three proteins was detected between the experimental and normal groups (P > 0.05). CONCLUSIONS: Blockage of costimulatory signal CD(86) at early pregnancy can treat uncertain recurrent spontaneous abortion by stimulating the expression of TGF-beta(1), MMP-9 and PAI-1 and reducing the embryo resorption rate.

[Relations between the expression of cyclin E, p16ink4, ki67 and HPV16/18 infection in cervical exfoliated cells].

OBJECTIVE: To confirm the relations between the expression of cyclin E, p16ink4, ki67 and HPV16/18 infection using cervical exfoliated cells, and evaluate the usefulness of cyclin E, p16ink4 and ki67 as biomarkers for screening of cervical carcinomas. METHODS: The expression of cyclin E, p16ink4 oncoproteins and ki67 proliferative activity was evaluated immunohistochemically in 78 cervical exfoliated epithelial specimens. Human papillomavirus type16 and 18 (HPV16/18) infection was assessed by polymerase chain reaction (PCR) using type specific primers. RESULTS: Cyclin E, p16ink4 and ki67 were all overexpressed in cervical preneoplasia and neoplasia cells, compared with little expressed in ASCUS (P less than 0.005). Overexpression of cyclin E was observed in CIN, (P less than 0.01), p16ink4 and ki67 overexpressed in invasive carcinoma(100 percent and 90.9 percent respectively). The degree of p16ink4 and ki67 expression correlated well with the degree of cervical neoplasia (P less than 0.005). HPV16 infection was assessed at all stages of cervical neoplasia samples, and a significant relationship with the degree of cervical epithelial lession was observed at the same time. The expression level of p16ink4 and ki67 seemed to be more closely associated with HPV16 infection than cyclin E did (rs=1.0 vs rs=0.4). HPV18 was found positive in only 1 case in CIN1 and in 4 cases in CIN2-3. Therefore no significance was found on statistical analysis (P less than 0.005). CONCLUSION: Cyclin E, p16ink4 and ki67 should be regarded as useful biomarkers of HPV-related cervical neoplasias, and be used for screening patients at high risk for developing cervical carcinomas. Moreover, cyclin E might be a significant cytologic marker for the primary screening of cervical carcinomas.

[Relationship among HPV16 infection and Expression of hTERT, p21waf1, Ki67 in cervical intraepithelial neoplasias and squamous cell carcinomas of cervix uteri].

BACKGROUND: To investigate the relationship among human papillomavirus (HPV)16 infection and the expression of telomerase catalytic protein subunit (hTERT), tumor suppressor gene p21waf1, proliferation antigen Ki67 in cervical intraepithelial neoplasias (CIN) and squamous cell carcinomas (SCC) of cervix uteri and their significance. METHODS: Tissue microarray combined with in situ hybridization (ISH) and immunohistochemical staining (EliVision plus method) was used to detect the expression of HPV16 RNA, hTERT, Ki67 and p21waf1 proteins in the cervix uteri specimens from 130 subjects, including normal cervical tissue (n=26), CIN (n=46) and SCC (n=58). RESULTS: (1) The positive rate of HPV16 hybridization signals and expression of hTERT, Ki67 in CINII-III, in situ carcinoma and invasive SCC were all significantly higher than in normal cervical tissue (P < 0.05 for all), and was also higher in SCC than in CIN (P < 0.05 for all). There was a significant difference among CIN I, II and III (P < 0.05 for all). (2) The positive expression of p21waf1 protein only in SCC was significantly lower than in normal cervical tissue (P < 0.05), but there was no significant differences among other groups (all P > 0.05). (3) The positive rate of HPV16 and the expression of Ki67 showed respectively positive being correlated with the expression of hTERT (P < 0.05, r=0.339; P < 0.05, r=0.398); HPV16, hTERT and Ki67 showed respectively negative correlation with the expression of p21waf1 (P < 0.05, r=-0.337; P < 0.05, r=-0.248; P < 0.05, r=-0.446); There was no significant relation between HPV16 and Ki67 (P > 0.05). CONCLUSION: The results suggest that in tissues of CIN and SCC changes in hTERT, p21waf1 and Ki67 expression may be associated with HPV16 infection and they interact with each other, which can influent the progression of CIN and carcinogenesis of SCC. These biomarkers may be analyzed comprehensively to reveal the detailed mechanism by which HPV16 participate in malignant transformation and to provide some informations on the diagnosis of patients with high risk for malignant progression. Tissue microarray is an efficient platform for high-throughput analysis of genes and their expression products in investigations.