Caffeic acid, but not ferulic acid, inhibits macrophage pyroptosis by directly blocking gasdermin D activation.

Regulated pyroptosis is critical for pathogen elimination by inducing infected cell rupture and pro-inflammatory cytokines secretion, while overwhelmed pyroptosis contributes to organ dysfunction and pathological inflammatory response. Caffeic acid (CA) and ferulic acid (FA) are both well-known antioxidant and anti-inflammatory phenolic acids, which resemble in chemical structure. Here we found that CA, but not FA, protects macrophages from both Nigericin-induced canonical and cytosolic lipopolysaccharide (LPS)-induced non-canonical pyroptosis and alleviates LPS-induced mice sepsis. It significantly improved the survival of pyroptotic cells and LPS-challenged mice and blocked proinflammatory cytokine secretion. The anti-pyroptotic effect of CA is independent of its regulations in cellular lipid peroxidation, mitochondrial function, or pyroptosis-associated gene transcription. Instead, CA arrests pyroptosis by directly associating with gasdermin D (GSDMD) and blocking its processing, resulting in reduced N-GSDMD pore construction and less cellular content release. In LPS-induced septic mice, CA inhibits GSDMD activation in peritoneal macrophages and reduces the serum levels of interleukin-1ß and tumor necrosis factor-α as the known pyroptosis inhibitors, disulfiram and dimethyl fumarate. Collectively, these findings suggest that CA inhibits pyroptosis by targeting GSDMD and is a potential candidate for curbing the pyroptosis-associated disease.

Repurposing of clinically approved drugs for treatment of coronavirus disease 2019 in a 2019-novel coronavirus-related coronavirus model.

BACKGROUND: Medicines for the treatment of 2019-novel coronavirus (2019-nCoV) infections are urgently needed. However, drug screening using live 2019-nCoV requires high-level biosafety facilities, which imposes an obstacle for those institutions without such facilities or 2019-nCoV. This study aims to repurpose the clinically approved drugs for the treatment of coronavirus disease 2019 (COVID-19) in a 2019-nCoV-related coronavirus model. METHODS: A 2019-nCoV-related pangolin coronavirus GX_P2V/pangolin/2017/Guangxi was described. Whether GX_P2V uses angiotensin-converting enzyme 2 (ACE2) as the cell receptor was investigated by using small interfering RNA (siRNA)-mediated silencing of ACE2. The pangolin coronavirus model was used to identify drug candidates for treating 2019-nCoV infection. Two libraries of 2406 clinically approved drugs were screened for their ability to inhibit cytopathic effects on Vero E6 cells by GX_P2V infection. The anti-viral activities and anti-viral mechanisms of potential drugs were further investigated. Viral yields of RNAs and infectious particles were quantified by quantitative real-time polymerase chain reaction (qRT-PCR) and plaque assay, respectively. RESULTS: The spike protein of coronavirus GX_P2V shares 92.2% amino acid identity with that of 2019-nCoV isolate Wuhan-hu-1, and uses ACE2 as the receptor for infection just like 2019-nCoV. Three drugs, including cepharanthine (CEP), selamectin, and mefloquine hydrochloride, exhibited complete inhibition of cytopathic effects in cell culture at 10 µmol/L. CEP demonstrated the most potent inhibition of GX_P2V infection, with a concentration for 50% of maximal effect [EC50] of 0.98 µmol/L. The viral RNA yield in cells treated with 10 µmol/L CEP was 15,393-fold lower than in cells without CEP treatment ([6.48 ±â€Š0.02] × 10vs. 1.00 ±â€Š0.12, t = 150.38, P < 0.001) at 72 h post-infection (p.i.). Plaque assays found no production of live viruses in media containing 10 µmol/L CEP at 48 h p.i. Furthermore, we found CEP had potent anti-viral activities against both viral entry (0.46 ±â€Š0.12, vs.1.00 ±â€Š0.37, t = 2.42, P < 0.05) and viral replication ([6.18 ±â€Š0.95] × 10vs. 1.00 ±â€Š0.43, t = 3.98, P < 0.05). CONCLUSIONS: Our pangolin coronavirus GX_P2V is a workable model for 2019-nCoV research. CEP, selamectin, and mefloquine hydrochloride are potential drugs for treating 2019-nCoV infection. Our results strongly suggest that CEP is a wide-spectrum inhibitor of pan-betacoronavirus, and further study of CEP for treatment of 2019-nCoV infection is warranted.

IL28B SNP rs12979860 is the Critical Predictor for Sustained Viral Response in Chinese Children Aged 1 to 6 Years with Chronic Hepatitis C.

Clinical data on children with chronic hepatitis C (CHC) remain extremely limited. This study investigated sustained virologic response (SVR) to alfa-interferon 2b plus RBV treatment in children aged 1-6 years with unsafe injection-acquired CHC. 154 children with CHC aged 1 to 6 years were enrolled, 101 of them were male (65.6%) and 53 were female (34.4%), and they were treated with alfa-interferon at a dose of 1-5 MIU/m2 3 times weekly plus oral RBV (15 mg/kg/day) for 48 weeks. 57(39.3 %) of them were genotype 1b, 73(50.3%) were genotypes 2a, 15(10.3%) were undecided type. SVR was achieved in 53 of 57(93.0%) patients with genotype 1b, in 72 (98.6%) of 73 with genotype 2a, 15(100.0%) of 15 with undecided type. There was no significant statistical difference in SVR between male and female (98.0% vs 94.3%, p=0.340), genotype 2a and those with genotype 1b(98.6% vs 93.0%, p=0.160), ALT>40U/L group and ALT≤40U/L group(96.7% vs 96.8%, p=1.000), AST>40U/L group and AST≤40U/L group(95.9% vs 98.2%, p=0.654) as well as lower baseline viral load group (<6×105 IU/ml) and higher baseline viral load group(≥6×105 IU/ml)(97.3% vs 95.3%, p=0.916). Leucopenia, neutropenia, hemoglobin concentration decrease, fever, platelet count decrease and rash were 8.4%, 69.5%, 24.0%, 50.6%, 1.9% and 4.5%, respectively. And only 12(7.8%) individuals developed thyroid autoantibodies. The SVR was higher in patients with IL-28B genotype C/C than C/T (99.0% vs 80%, p=0.002). Compared with HCV viral genotype, ALT level and baseline viral load, IL-28B rs12979860 is more suitable for predicting antiviral efficacy in children with CHC. It is inappropriate to take the increase of ALT level as an essential indicator for antiviral treatment in children aged 1-6 years.

[Utility of high throughput sequencing technology in analyzing the terminal sequence of caudovirales bacteriophage genome].

To confirm the hypothesis that the high frequency sequences of high throughput sequencing are the terminal sequences of the bacteriophage genome. An adaptor of specific sequence was linked to the end of the bacteriophage T3 genomic DNA, which was then subject to high throughput sequencing; as a control, the same T3 genomic DNA without adaptor was also analyzed by high throughput sequencing. The sequencing results were examined with bioinformatics software. Similar high throughput sequencing technique was applied to analyze the genomic sequence of N4-like bacteriophage IME11. Bioinformatics study showed that the sequences tagged with adaptors were consistent with the high frequency sequences without adaptor labeling. Our analysis also indicated that the end of the T4-like phage genome had specific sequences instead of random sequences, disagreeing with the previous assertion. Evidences were provided that N4-like bacteriophage had a particular terminal sequence: the left end of the genome was unique while the right end was permuted. The high throughput sequencing technique was convenient and practical to be used to simultaneously detect the terminal sequence and the complete sequence of bacteriophage genome.