ACE2-independent infection of T lymphocytes by SARS-CoV-2

SARS-CoV-2 induced marked lymphopenia in severe patients with COVID-19. However, whether lymphocytes are targets of viral infection is yet to be determined, although SARS-CoV-2 RNA or antigen has been identified in T cells from patients. Here, we confirmed that SARS-CoV-2 viral antigen could be detected in patient peripheral blood cells (PBCs) or postmortem lung T cells, and the infectious virus could also be detected from viral antigen-positive PBCs. We next prove that SARS-CoV-2 infects T lymphocytes, preferably activated CD4 + T cells in vitro. Upon infection, viral RNA, subgenomic RNA, viral protein or viral particle can be detected in the T cells. Furthermore, we show that the infection is spike-ACE2/TMPRSS2-independent through using ACE2 knockdown or receptor blocking experiments. Next, we demonstrate that viral antigen-positive T cells from patient undergone pronounced apoptosis. In vitro infection of T cells induced cell death that is likely in mitochondria ROS-HIF-1a-dependent pathways. Finally, we demonstrated that LFA-1, the protein exclusively expresses in multiple leukocytes, is more likely the entry molecule that mediated SARS-CoV-2 infection in T cells, compared to a list of other known receptors. Collectively, this work confirmed a SARS-CoV-2 infection of T cells, in a spike-ACE2-independent manner, which shed novel insights into the underlying mechanisms of SARS-CoV-2-induced lymphopenia in COVID-19 patients.

SFTSV Infection Induces BAK/BAX-Dependent Mitochondrial DNA Release to Trigger NLRP3 Inflammasome Activation

Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) is an emerging tick-borne virus that carries a high fatality rate of 12%-50%. In-depth understanding of the SFTSV-induced pathogenesis mechanism is critical for developing effective anti-SFTS therapeutics. Here, we report transcriptomic analysis of blood samples from SFTS patients. We observe a strong correlation between inflammatory responses and disease progression and fatal outcome. Quantitative proteomic analysis of SFTSV infection confirms the induction of inflammation and further reveals virus-induced mitochondrial dysfunction. Mechanistically, SFTSV infection triggers BCL2 antagonist/killer 1 (BAK) upregulation and BAK/BCL2-associated X (BAX) activation, leading to mitochondrial DNA (mtDNA) oxidization and subsequent cytosolic release. The cytosolic mtDNA binds and triggers NLRP3 inflammasome activation. Notably, the BAK expression level correlates with SFTS disease progression and fatal outcome. These findings provide insights into the clinical features and molecular underpinnings of severe SFTS, which may aid in patient care and therapeutic design, and may also be conserved during infection by other highly pathogenic viruses.

Follicle Stimulating Hormone Inhibits the Expression of p53 Up-Regulated Modulator of Apoptosis Induced by Reactive Oxygen Species Through PI3K/Akt in Mouse Granulosa Cells

In mammalian ovaries, follicular atresia occurs periodically and destroys almost all the follicles in the ovary. Follicle-stimulating hormone (FSH) acts as the primary survival factor during follicular atresia by preventing apoptosis in granulosa cells (GCs). Many studies have demonstrated that oxidative stress-induced apoptosis is a main cause of follicular atresia. Reactive oxygen species (ROS)-induced GCs apoptosis is regulated by a variety of signaling pathways involving numerous genes and transcription factors. Therefore, we examined whether FSH inhibits the expression of p53 up-regulated modulator of apoptosis (PUMA) induced by reactive oxygen species (ROS) through phosphoinositide 3-kinase (PI3K) / protein kinase B (AKT) in mouse GCs. In vivo study: thirty-two-mice were randomly assigned to four groups and given FSH. We found that FSH can inhibit the 3-nitropropionic acid (3-NP) induced apoptosis and PUMA expression in mRNA level. Moreover, In vitro experiment, we found that FSH can inhibit the H(2)O(2)-induced apoptosis and PUMA expression in mRNA level. Additionally, we also found that PI3K/AKT inhibitor LY294002 abolished the downregulation of PUMA mRNA by FSH in vitro, In conclusion, FSH inhibit the expression of PUMA induced by ROS through PI3K/AKT pathway in vivo and vitro.

Interaction between synchronous bilateral prophylactic oophorectomy and adjuvant chemotherapy in female patients with locally advanced colorectal cancer

AIM

In this study we explored the prognostic impact of synchronous bilateral prophylactic oophorectomy in female patients with primary colorectal cancer undergoing radical surgery.

METHOD

From 1991 to 2000, 267 female patients with stage II or stage III colorectal cancer, who had undergone curative resection, were retrospectively reviewed. In 224 patients, the ovaries were preserved. The other 43 patients underwent synchronous bilateral prophylactic oophorectomy. Univariate and multivariate analyses (Kaplan-Meier and Cox regression, respectively) were used to evaluate the effect of prophylactic oophorectomy and other clinical factors on the prognosis of patients.

RESULTS

Both univariate and multivariate analyses showed that tumor stage and adjuvant chemotherapy were the only two significant clinical factors that affected the 5-year overall survival of patients (P < 0.01). There was no significant difference in the 5-year overall survival between patients who had, or had not, undergone prophylactic oophorectomy (75%vs 73%, P > 0.05). In the subgroup analysis by adjuvant chemotherapy, the 5-year overall survival in patients receiving adjuvant chemotherapy was similar between nonoophorectomy and oophorectomy groups. However, in patients without adjuvant chemotherapy, the oophorectomy group was shown to have a significantly better 5-year overall survival than the nonoophorectomy group (76%vs 51%, P = 0.047).

CONCLUSION

Prophylactic oophorectomy may improve the overall survival of female patients with locally advanced colorectal cancer without adjuvant chemotherapy, but its survival benefit vanished in patients receiving adjuvant chemotherapy. The role of prophylactic oophorectomy may be substituted by adjuvant chemotherapy, which makes prophylactic oophorectomy unnecessary during surgery for locally advanced colorectal cancer.

Effect of simulated weightlessness on the response characteristics of human brain

In order to systematically investigate the effects of simulated weightlessness on the function state of human brain, 15 degrees head-down tilt (HDT) was used to simulate weightlessness, and the response changes of event-related EEG power spectra, medium-frequency synchronous potentials and slow-waves were examined in the present study. It was found that HDT had characteristic effects on the above EEG responses, suggesting that the effects mainly occurred in the brain's regulatory system, therefore, resulting in changes of the brain function state.