Characterization and phylogenetic analysis of a neurovirulent Zika virus isolated from Cambodia in 2019.

The geographic range of Zika virus (ZIKV) has expanded from Asia to the Americas, leading to the 2015-2016 pandemic with enhanced neurovirulence. At present, ZIKV is continuously circulating in many Southeast Asian countries. Unfortunately, the persistent evolution of ZIKV in Southeast Asia and its influence on the biological characteristics of the virus remain incompletely understood. In this study, the in vitro and in vivo properties of a new ZIKV isolate obtained from Cambodia in 2019 (CAM/2019) were characterized and compared with those of the Cambodian strain (CAM/2010). Compared with CAM/2010, the CAM/2019 virus showed similar plaque morphology and growth curves in cell cultures and induced comparable viremia and organ viral loads profiles in both BALB/c and A129 (IFNAR1-/- ) mice upon intraperitoneal (i.p.) inoculation. Remarkably, the CAM/2019 virus exhibited enhanced neurovirulence in neonatal mice compared with CAM/2010, with a 74-fold reduction in the 50% lethal dose (LD50 ). Consistently, CAM/2019 produced higher viral loads in the brains of BALB/c neonatal mice than CAM/2010 did. Sequence alignment showed that the CAM/2019 virus has acquired 12 amino acid substitutions, several of which were found to be associated with neurovirulence. In particular, the CAM/2019 virus shared an A1204T substitution in NS2A with the Thai isolate SI-BKK02 that was isolated from a microcephaly case. Taken together, our results indicate that a ZIKV strain isolated with specific mutations has emerged in Cambodia, highlighting the need for extensive molecular and disease surveillance in Cambodia and other Asian countries.

Tofacitinib enhances IGF1 via inhibiting STAT6 transcriptionally activated-miR-425-5p to ameliorate inflammation in RA-FLS.

Rheumatoid arthritis (RA) is a systemic autoimmune disease, which has been reported closely associated with the dysfunction of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. This study aims to explore the potential therapeutic effect of Tofacitinib, a putative JAK/STAT inhibitor, in RA. Tofacitinib suppressed proliferation and accelerated apoptosis of rheumatoid arthritis synovial fibroblasts (RA-FLS) as confirmed by CCK-8, EdU and Western blot assays. Tofacitinib significantly inhibited expression of pro-inflammatory factors including tumor necrosis factor-α (TNF-α), vascular endothelial growth factor A, matrix metalloproteinase 1, matrix metalloproteinase 3, interleukin-6 and interferon gamma in RA-FLS cells. mechanistically, tofacitinib decreased signal transducer and activator of transcription 6 (STAT6), which transcriptionally activates miR-425-5p, and thus increased insulin like growth factor 1 (IGF1) expression, a target of miR-425-5p in RA-FLS. Overexpression of STAT6 restored the expression of pro-inflammatory factors and proliferation inhibited by Tofacitinib in RA-FLS. Overall, Tofacitinib exerted inhibitory effect on proliferation and inflammation of RA-FLS through modulating STAT6/miR-425-5p/IGF1 signal axis. These findings shed light on the novel strategies for improving RA.

Effect of Melatonin on the Extracellular-Regulated Kinase Signal Pathway Activation and Human Osteoblastic Cell Line hFOB 1.19 Proliferation.

It has been shown that melatonin may affect bone metabolism. However, it is controversial whether melatonin could promote osteoblast proliferation, and the precise molecular mechanism of melatonin on osteoblast proliferation is still obscure. In this study, the results of the CCK-8 assay showed that melatonin significantly promoted human osteoblastic cell line hFOB 1.19 cell proliferation at 1, 2.5, 5, 10, 25, 50 and 100 µM concentrations for 24 h, but there were no significant differences among the groups. Western blot demonstrated that 10 µM melatonin significantly promoted ERK1/2 phosphorylation. Furthermore, we also detected the phosphorylation of c-Raf, MEK1/2, p90RSK and MSK1, and all of them increased with 10 µM melatonin. U0126 (a selective inhibitor of MEK that disrupts downstream activation of ERK1/2) downregulated the phosphorylation of ERK1/2, p90RSK and MSK1. U0126 also attenuated the proliferation of osteoblasts stimulated by melatonin. In conclusion, this study for the first time indicates that melatonin (10 nM-100 µM) promotes the proliferation of a human osteoblastic cell line hFOB 1.19 through activation of c-Raf, MEK1/2, ERK1/2, p90RSK and MSK1.

METTL3 Regulates the m6A Modification of NEK7 to Inhibit the Formation of Osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a common degenerative joint disease. The occurrence of OA slowly destroys the soft tissue structure of the patient's joint. Severe cases could lead to disability. Current studies had shown that inhibition of chondrocytes pyroptosis could slow down the progression of OA. Our work aimed to explore the specific mechanisms and ways of regulating this process. DESIGN: In this work, the level of N6-methyladenosine (m6A) in clinical tissues was detected by ribonucleic acid (RNA) m6A dot blot. qRT-PCR (quantitative real-time polymerase chain reaction) was used to detect the messenger RNA (mRNA) expression level of m6A modified enzyme in clinical tissues. MTT (3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromid) and flow cytometry were used to detect the effect of sh-METTL3 (methyltransferase like 3) and NIMA-related kinase 7 (NEK7) transfection on chondrocytes pyroptosis in OA. Western blot was used to detect the protein expression levels of pyroptosis-related proteins. ELISA (enzyme-linked immunosorbent assay) was used to measure the protein concentration of inflammatory cytokines. The SRAMP online database was used to predict the m6A site of NEK7. HE staining was used to assess the progression of OA in mice. RESULTS: The level of m6A in clinical samples of OA patients was higher, and METTL3 was significantly higher expressed in clinical samples of OA patients. We provided evidence that low expression of METTL3 inhibited chondrocytes pyroptosis. In addition, Rescue experiments and in vivo experiments had shown that METTL3 in combination with NEK7 inhibited the progression of OA by promoting chondrocytes pyroptosis. CONCLUSIONS: METTL3 regulates m6A modification of NEK7 and inhibits OA progression.

An Engineered IgG-VHH Bispecific Antibody against SARS-CoV-2 and Its Variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies are shown to be effective therapeutics for providing coronavirus disease 2019 (COVID-19) protection. However, recurrent variants arise and facilitate significant escape from current antibody therapeutics. Bispecific antibodies (bsAbs) represent a unique platform to increase antibody breadth and to reduce neutralization escape. Herein, a novel immunoglobulin G-variable domains of heavy-chain-only antibody (IgG-VHH) format bsAb derived from a potent human antibody R15-F7 and a humanized nanobody P14-F8-35 are rationally engineered. The resulting bsAb SYZJ001 efficiently neutralizes wild-type SARS-CoV-2 as well as the alpha, beta, gamma, and delta variants, with superior efficacy to its parental antibodies. Cryo-electron microscopy structural analysis reveals that R15-F7 and P14-F8-35 bind to nonoverlapping epitopes within the RBD and sterically hindered ACE2 receptor binding. Most importantly, SYZJ001 shows potent prophylactic and therapeutic efficacy against SARS-CoV-2 in three established mouse models. Collectively, the current results demonstrate that the novel bsAb format is feasible and effective, suggesting great potential as an inspiring antiviral strategy.

Revolutionizing car body manufacturing using a unified steel metallurgy concept.

Numerous high-performance steels with various compositions and mechanical properties were developed to enable a safe and light-weight automotive body-in-white (BIW). However, this multisteel scheme creates substantial challenges, including the resistance spot welding of dissimilar steels, processing optimization, and recycling. Here, we propose a revolutionary unified steel (UniSteel) concept, i.e., using a single chemistry to produce multiple steel grades for the entire BIW. The tensile strengths of various UniSteel grades are ranging from 600 to 1680 MPa, encompassing the strengths of typical commercial counterparts while exhibiting competent ductility. The prototype parts made of UniSteel press-hardened steel (PHS) grade demonstrate superior side-intrusion resistance over the commercial PHS, and the satisfactory weldability is verified. The UniSteel reduces the resistivity difference within the sheet stack-ups, allowing the simplification of welding processes. The UniSteel concept could potentially revolutionize the manufacturing of BIW for the global automotive industry and contribute to carbon neutrality.

Dynamic investigation of interface atom migration during heterostructure nanojoining.

Interface atom migration and compositional evolution during the heterostructure nanojoining process under external electrical loadings has been investigated in situ inside a transmission electron microscope with atomic resolution. The results indicate that the migration of oxygen atoms on the contact interface of metal nanorods is a thermal dominated process rather than an electromigration process. After removing the oxide layer at the nanometal contact interface, the metal atoms migrate under external electrical field. The formation region of nanoalloys can be modulated by controlling the electromigration direction of nanometal atoms, leading to an electromigration-dominated cutting process which offers an extra degree of freedom to design a sacrifice layer and interconnects in solid-state bonding. These findings offer an insight of potential failure mechanisms as well as fabrication methodology for interconnects in nanodevices.

Anti-edema effect of epigallocatechin gallate on spinal cord injury in rats.

Recent studies indicated that epigallocatechin gallate (EGCG) had neuroprotective effects on spinal cord injury (SCI).The current study was performed to determine the anti-edema effect of EGCG after SCI in rats. EGCG (100 mg/kg, i.p.) was administered to rats immediately following SCI. It was found that EGCG (100 mg/kg) could significantly reduce spinal cord water content. In addition, EGCG (100mg/kg) significantly reduced the expression of aquaporin-4(AQP4) and glial fibrillary acidic protein (GFAP) level at 24, 48 and 72h after injury, but it did not have this effect at 12 h after injury. The changes of AQP4 and GFAP protein induced by EGCG (100 mg/kg) treatment were accompanied by a reduction of spinal cord edema. Our results indicated that EGCG (100 mg/kg) could reduce spinal cord edema after SCI, which could be correlated with the down-regulation the expression of AQP4 and GFAP protein level after SCI.