Frontiers of medicine
-
In recent years, studying the role of myeloid-derived suppressor cells (MDSCs) in many pathological inflammatory conditions has become a very active research area. Although the role of MDSCs in cancer is relatively well established, their role in non-cancerous pathological conditions remains in its infancy resulting in much confusion. ⋯ The following topics will be specifically focused upon: (1) definition and characterization of MDSCs; (2) whether all MDSC populations consist of immature cells; (3) technical issues in MDSC isolation, estimation and characterization; (4) the origin of MDSCs and their anatomical distribution in health and disease; (5) mediators of MDSC expansion and accumulation; (6) factors that determine the expansion of one MDSC population over the other; (7) the Yin and Yang roles of MDSCs. Moreover, the functions of MDSCs will be addressed throughout the text.
-
Frontiers of medicine · Apr 2021
H. sinensis mycelium inhibits epithelial-mesenchymal transition by inactivating the midkine pathway in pulmonary fibrosis.
The medical fungus Hirsutella sinensis has been used as a Chinese folk health supplement because of its immunomodulatory properties. Our previous studies established the antifibrotic action of Hirsutella sinensis mycelium (HSM) in the lung. The epithelial-mesenchymal transition (EMT) is involved in the pathogenesis of idiopathic pulmonary fibrosis. ⋯ The activation of midkine related signaling pathway is ameliorated following HSM treatment, whereas this extract also caused an effective attenuation of the induction of EMT (caused by midkine overexpression) in vitro. Results further confirm that oral medication of HSM disrupted the midkine pathway in vivo. Overall, findings suggest that the midkine pathway and the regulation of the EMT may be considered novel candidate therapeutic targets for the antifibrotic effects caused by HSM.
-
Frontiers of medicine · Apr 2021
Degradation of SARS-CoV-2 receptor ACE2 by the E3 ubiquitin ligase Skp2 in lung epithelial cells.
An unexpected observation among the COVID-19 pandemic is that smokers constituted only 1.4%-18.5% of hospitalized adults, calling for an urgent investigation to determine the role of smoking in SARS-CoV-2 infection. Here, we show that cigarette smoke extract (CSE) and carcinogen benzo(a)pyrene (BaP) increase ACE2 mRNA but trigger ACE2 protein catabolism. ⋯ Tobacco carcinogens inhibit SARS-CoV-2 spike protein pseudovirions infection of the cells. Given that tobacco smoke accounts for 8 million deaths including 2.1 million cancer deaths annually and Skp2 is an oncoprotein, tobacco use should not be recommended and cessation plan should be prepared for smokers in COVID-19 pandemic.
-
Frontiers of medicine · Dec 2020
Chinese herbal medicine reduces mortality in patients with severe and critical Coronavirus disease 2019: a retrospective cohort study.
This study aimed to evaluate the efficacy of Chinese herbal medicine (CHM) in patients with severe/critical coronavirus disease 2019 (COVID-19). In this retrospective study, data were collected from 662 patients with severe/critical COVID-19 who were admitted to a designated hospital to treat patients with severe COVID-19 in Wuhan before March 20, 2020. All patients were divided into an exposed group (CHM users) and a control group (non-users). ⋯ After multivariate adjustment, the mortality risk of CHM users was reduced by 82.2% (odds ratio 0.178, 95% CI 0.076-0.418; P < 0.001) compared with the non-users. Secondly, age (odds ratio 1.053, 95% CI 1.023-1.084; P < 0.001) and the proportion of severe/critical patients (odds ratio 0.063, 95% CI 0.028-0.143; P < 0.001) were the risk factors of mortality. These results show that the use of CHM may reduce the mortality of patients with severe/critical COVID-19.
-
Frontiers of medicine · Dec 2020
Durability of neutralizing antibodies and T-cell response post SARS-CoV-2 infection.
The ongoing pandemic of Coronavirus disease 19 (COVID-19) is caused by a newly discovered β Coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). How long the adaptive immunity triggered by SARS-CoV-2 can last is of critical clinical relevance in assessing the probability of second infection and efficacy of vaccination. Here we examined, using ELISA, the IgG antibodies in serum specimens collected from 17 COVID-19 patients at 6-7 months after diagnosis and the results were compared to those from cases investigated 2 weeks to 2 months post-infection. ⋯ Notably, 14 samples available at 6-7 months post-infection all showed significant neutralizing activities in a pseudovirus assay, with no difference in blocking the cell-entry of the 614D and 614G variants of SARS-CoV-2. Furthermore, in 10 blood samples from cases at 6-7 months post-infection used for memory T-cell tests, we found that interferon γ-producing CD4+ and CD8+ cells were increased upon SARS-CoV-2 antigen stimulation. Together, these results indicate that durable anti-SARS-CoV-2 immunity is common in convalescent population, and vaccines developed from 614D variant may offer protection from the currently predominant 614D variant of SARS-CoV-2.