Investigating Derivatives of Tanshinone IIA Sulfonate Sodium and Chloroxine for Their Inhibition Activities against the SARS-CoV-2 Papain-like Protease.

SARS-CoV-2 has caused a global pandemic of COVID-19, posing a huge threat to public health. The SARS-CoV-2 papain-like cysteine protease (PLpro) plays a significant role in virus replication and host immune regulation, which is a promising antiviral drug target. Several potential inhibitors have been identified in vitro. However, the detailed mechanism of action and structure-activity relationship require further studies. Here, we investigated the structure-activity relationships of the series of derivatives of tanshinone IIA sulfonate sodium (TSS) and chloroxine based on biochemical analysis and molecular dynamics simulation. We found that compound 7, a derivative of chloroxine, can disrupt PLpro-ISG15 interaction and exhibits an antiviral effect for SARS-CoV-2 variants (wild type, delta, and omicron) at the low micromolar level. These studies confirmed that inhibiting PLpro-ISG15 interaction and, thus, restoring the host's innate immunity are effective methods for fighting against viral infection.

Amelioration of type 1 diabetes by recombinant fructose-1,6-bisphosphate aldolase and cystatin derived from Schistosoma japonicum in a murine model.

Infection with helminth parasites or the administration of their antigens can prevent or attenuate autoimmune diseases. To date, the specific molecules that prime the amelioration are only limited. In this study, recombinant Schistosoma japonicum cystatin (rSjcystatin) and fructose-1,6-bisphosphate aldolase (rSjFBPA) were administered to female NOD mice via intraperitoneal (i.p.) injection to characterize the immunological response by the recombinant proteins. We have shown that the administration of rSjcystatin or rSjFBPA significantly reduced the diabetes incidence and ameliorated the severity of type 1 diabetes mellitus (T1DM). Disease attenuation was associated with suppressed interferon-gamma (IFN-γ) production in autoreactive T cells and with a switch to the production of Th2 cytokines. Following rSjcystatin or rSjFBPA injection, regulatory T cells (Tregs) were remarkably increased, which was accompanied by increased expression of interleukin-10 (IL-10) and transforming growth factor beta (TGF-ß). Our study suggests that helminth-derived proteins may be useful in strategies to limit pathology by promoting the Th2 response and upregulating Tregs during the inflammatory tissue-damage process in T1DM.

[Association of murine double minute 2 and P53 polymorphisms with breast cancer susceptibility].

OBJECTIVE: To investigate the combined effects between the two polymorphisms murine double minute 2 (MDM2) rs2279744 T→G and P53 rs1042522 G→C on the genetic susceptibility of breast cancer. METHODS: A total of 600 female patients with diagnosed breast cancer were consecutively recruited from the Yuhang district, Hangzhou city during March 2001 to May 2009. In the same period as the cases were collected, 600 healthy women living in Yuhang district, Hangzhou city were selected from a nutritional survey conducted. Peripheral blood lymphocytes were obtained from the study subjects and the demographic information were collected through questionnaires. PCR-restriction fragment length polymorphism (PCR-RFLP) was used for genotyping MDM2 rs2279744 T→G and P53 rs1042522 G→C. Logistic regression analysis was used to analyze the combined effects of the two polymorphisms on breast cancer risk. RESULTS: The frequency of MDM2 rs2279744 GG, TG and TT genotypes were 31.5% (189/600), 45.5% (273/600), 23.0% (138/600) in case group and 19.0% (114/600), 49.2% (295/600), 31.8% (191/600) in control group. The frequency of P53 rs1042522 GG, GC and CC genotypes were 23.1% (139/600), 50.2% (301/600), 26.7% (160/600) in case group and 30.5% (183/600), 51.3% (308/600), 18.2% (109/600) in control group. Logistic regression analysis showed that carriers with rs2279744 TG, GG genotypes had a significant increased risk for developing breast cancer compared with rs2279744 TT carriers (OR = 1.31, 95%CI: 0.97 - 1.73 for TG; OR = 2.24, 95%CI: 1.61 - 3.09 for GG). When comparing with rs1042522 GG carriers, carriers with rs1042522 GC, CC genotypes had a significant increased risk for developing breast cancer (OR = 1.34, 95%CI: 0.94 - 1.68 for GC; OR = 1.89, 95%CI: 1.35 - 2.68 for CC). The united analysis of this two polymorphisms showed that compared with individuals carrying rs2279744 TT and rs1042522 GG (the frequency were 4.8% (29/600) in case group and 11.5% (69/600) in control group), carries with rs2279744 TG/GG and rs1042522 GC/GG genotypes (the frequency were 95.2% (571/600) in case group and 88.5% (531/600) in control group) showed significant higher risk in the susceptibility to breast cancer (OR = 2.30, 95%CI: 1.39 - 3.82 for TG/GC + GG; OR = 2.14, 95%CI: 1.29 - 3.55 for TT + GC/CC; OR = 2.86, 95%CI: 1.80 - 4.53 for TG/GG + GC/CC). The combination of MDM2 rs2279744 T→G and P53 rs1042522 G→C contributed to a significantly higher risk of breast cancer than did any one of the variant (P = 0.046). The risk of susceptibility to breast cancer was much higher when this two polymorphisms both variant. CONCLUSIONS: The MDM2 rs2279744 T→G and P53 rs1042522 G→C may be risk factor for breast cancer. Significant combined effects between the two polymorphisms may contribute to the genetic susceptibility to breast cancer.

Inhibition of herpes simplex virus infection by oligomeric stilbenoids through ROS generation.

Stilbenoids including resveratrol contain the basic structural unit of 1,2-diphenylethylene. Naturally occurring stilbenoids have broad structural features due to oligomerization and modifications and some have demonstrated potent biological activities. In an effort to identify bioactive stilbenoids, we screened a group of dimeric and oligomeric stilbenoids against HSV-1 and HSV-2 infection. Several trimeric and tetrameric derivatives showed anti-herpetic activity at single digit micromolar concentrations. HSV-1 and HSV-2 replication requires for NF-κB and MAPK activation. The compounds showed no inhibitory activity against NF-κB and Erk/MAPK activation, instead those compounds promoted rapid and transient release of reactive oxygen species (ROS). Addition of N-acetylcysteine (NAC), a scavenger of ROS, reversed the inhibitory effect of those compounds against HSV replication. In addition to the identification of resveratrol derivatives with potent anti-HSV activity, our results uncover a mechanism of polyphenol-mediated anti-HSV response, linking anti-herpetic activity of oligomeric stilbenoids to innate immunity.

Syndecan-4 over-expression preserves cardiac function in a rat model of myocardial infarction.

Syndecan-4 (synd4) is a heparan sulfate proteoglycan, involved in repair following tissue damage, through modulating neovascularization and inflammation. In acute myocardial infarction its myocardial expression is up-regulated in a time-dependent manner, and in synd4-deficient mice severe cardiac dysfunction and abnormal remodeling are observed following induction of myocardial infarction. Here we explored the therapeutic potential of sustained synd4 over-expression in the context of myocardial infarction. Adenovirus containing the synd4 gene (Ad-synd4), or corresponding control adenovirus (Ad-null), was administered intramyocardially in rats immediately after induction of myocardial infarction. Cardiac function was ascertained by echocardiography, hemodynamic assessment and brain natriuretic peptide level 28 days post-intervention. Hearts were excised for molecular and histological analyses at predetermined time points. We observed reduced mortality and improved cardiac function post-myocardial infarction in the Ad-synd4 as compared to the Ad-null group, with associated attenuation of cardiac remodeling, less myocyte loss and reduced fibrosis. Additionally, the Ad-synd4 group exhibited endothelial cell activation and increased angiogenesis and arteriogenesis in the myocardium. The Ad-synd4 group also showed evidence of reduced myocardial inflammation as compared with the Ad-null group, with reduced inflammatory cell (CD45+) and myofibroblast (α-SMA+) infiltration as well as suppressed collagen III deposition and iNOS expression. Our results suggest that sustained synd4 over-expression in the myocardium is of therapeutic benefit following experimental myocardial infarction, through inducing neovascularization, suppressing tissue inflammation and fibrosis, with resultant improvements in cardiac function and remodeling.

Identification of OASL d, a splice variant of human OASL, with antiviral activity.

The 2',5'-oligoadenylate synthetases (OASs) are IFN-induced antiviral proteins and are upregulated by infection of viral and some bacterial pathogens. There are at least 2 transcripts of approximately 1.8 and 2.0 kb in interferon-beta treated samples that are recognized by a probe for human OASL in Northern blot assay. By RT-PCR amplification we have isolated a previously undescribed splice variant of human OASL, named OASL d. The new variant was derived from deletion of exons 4 and 5 and encodes a protein of 384 aa residues that shares the N-terminal 219 aa residues with OASL a. Sequence analysis indicates that OASL d also contains the entire ubiquitin-like domain identified in human OASL a. OASL d was strongly induced by IFNγ in THP-1 monocytic cells and in A549 epithelial cells by interferon-beta as detected by immunoblotting assay. Ectopic expression of OASL a or OASL d, but not OASL b that shares the N-terminus with OASL a and d, partially inhibited EV71 and VSV infection. No effect against HSV-2 infection was observed. Therefore, OASL d is a novel isoform of human OASL that possesses antiviral activity against RNA viruses.