SARS-CoV-2 aberrantly elevates mitochondrial bioenergetics to induce robust virus propagation.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a 'highly transmissible respiratory pathogen, leading to severe multi-organ damage. However, knowledge regarding SARS-CoV-2-induced cellular alterations is limited. In this study, we report that SARS-CoV-2 aberrantly elevates mitochondrial bioenergetics and activates the EGFR-mediated cell survival signal cascade during the early stage of viral infection. SARS-CoV-2 causes an increase in mitochondrial transmembrane potential via the SARS-CoV-2 RNA-nucleocapsid cluster, thereby abnormally promoting mitochondrial elongation and the OXPHOS process, followed by enhancing ATP production. Furthermore, SARS-CoV-2 activates the EGFR signal cascade and subsequently induces mitochondrial EGFR trafficking, contributing to abnormal OXPHOS process and viral propagation. Approved EGFR inhibitors remarkably reduce SARS-CoV-2 propagation, among which vandetanib exhibits the highest antiviral efficacy. Treatment of SARS-CoV-2-infected cells with vandetanib decreases SARS-CoV-2-induced EGFR trafficking to the mitochondria and restores SARS-CoV-2-induced aberrant elevation in OXPHOS process and ATP generation, thereby resulting in the reduction of SARS-CoV-2 propagation. Furthermore, oral administration of vandetanib to SARS-CoV-2-infected hACE2 transgenic mice reduces SARS-CoV-2 propagation in lung tissue and mitigates SARS-CoV-2-induced lung inflammation. Vandetanib also exhibits potent antiviral activity against various SARS-CoV-2 variants of concern, including alpha, beta, delta and omicron, in in vitro cell culture experiments. Taken together, our findings provide novel insight into SARS-CoV-2-induced alterations in mitochondrial dynamics and EGFR trafficking during the early stage of viral infection and their roles in robust SARS-CoV-2 propagation, suggesting that EGFR is an attractive host target for combating COVID-19.

Efficacy and Safety of Korean Herbal Medicine for Patients with Post-Accident Syndrome, Persistent after Acute Phase: A Pragmatic Randomized Controlled Trial.

This is a pragmatic, two-armed, parallel, single-center, randomized controlled clinical trial for comparative evaluation between the effectiveness of integrated Korean medicine (IKM) and herbal medicine treatment with that of IKM monotherapy (control) for post-accident syndrome persistent after the acute phase. Participants were randomized into Herbal Medicine (HM, n = 20) and Control groups (n = 20) to receive the allocated treatment of 1-3 sessions/week for 4 weeks. Intention-to-treat analysis was conducted. The Difference of Numeric Rating Scale (NRS) change of overall post-accident syndromes from baseline to week 5 for the two groups was 1.78 (95% CI: 1.08-2.48; p < 0.001). Regarding secondary outcomes, a significant decrease compared to the baseline values was confirmed for NRS of musculoskeletal, neurological, psychiatric complaints and general symptoms of post-accident syndromes. In a survival analysis based on the recovery criteria of "patients with a reduction in the NRS of overall post-accident syndromes of ≥50%," the HM group showed a shorter time to recovery than the control group during the 17-week study period (p < 0.001 by the log-rank test). IKM combined with herbal medicine treatment significantly improved the quality of life by relieving somatic pain and alleviating the overall post-accident syndrome persistent after the acute phase; this effect was maintained for at least 17 weeks.

Mechanical properties and thermal stability of intermolecular-fitted poly(vinyl alcohol)/α-chitin nanofibrous mat.

The major disadvantage of electrospun nanofibrous mats is their poor mechanical properties, which result from interfibrillar slips, porous structures, and the isotropic conformation of functional groups in fibers. In this work, we develop a tough electrospun mat without cost of both the stiffness and extensibility by combining two mutually exclusive polymers, i.e., generally "ductile" poly(vinyl alcohol) (PVA) and "stiff" α-chitin. The toughness of PVA/α-chitin is considerably higher (∼20 times) compared to PVA via intermolecular-fitted design and stoichiometric balance between hydrogen bonding donors and acceptors. Moreover, consistently oriented functional groups that are perpendicular to nanofibers improve mechanical properties. As a result, stiffness and extensibility are simultaneously increased by ∼19.3 and ∼3.8 times, respectively compared to PVA. The thermal stability with a 2.80-fold larger melting enthalpy of 823.95 ± 7.05 J g-1 than PVA. The great thermomechanical performance provides an insight for molecular design in electrospun nanofibers with chitin polymorphs.

Different Molecular Interaction between Collagen and α- or ß-Chitin in Mechanically Improved Electrospun Composite.

Although collagens from vertebrates are mainly used in regenerative medicine, the most elusive issue in the collagen-based biomedical scaffolds is its insufficient mechanical strength. To solve this problem, electrospun collagen composites with chitins were prepared and molecular interactions which are the cause of the mechanical improvement in the composites were investigated by two-dimensional correlation spectroscopy (2DCOS). The electrospun collagen is composed of two kinds of polymorphs, α- and ß-chitin, showing different mechanical enhancement and molecular interactions due to different inherent configurations in the crystal structure, resulting in solvent and polymer susceptibility. The collagen/α-chitin has two distinctive phases in the composite, but ß-chitin composite has a relatively homogeneous phase. The ß-chitin composite showed better tensile strength with ~41% and ~14% higher strength compared to collagen and α-chitin composites, respectively, due to a favorable secondary interaction, i.e., inter- rather than intra-molecular hydrogen bonds. The revealed molecular interaction indicates that ß-chitin prefers to form inter-molecular hydrogen bonds with collagen by rearranging their uncrumpled crystalline regions, unlike α-chitin.

First identification and phylogenetic analysis of equine hepacivirus in Korea.

Non-primate hepacivirus (NPHV) corresponds a group of isolates recently characterized in horses and dogs that present similar genomic organization and are closely related to hepatitis C virus. Since canine hapacivirus, NPHV identified in dogs, was first discovered in dogs in the United States, equine hepacivirus (EqHV, NPHV identified in horses) has been identified in horses in several countries. However, no epidemiological studies have investigated EqHV in horses in Korea. In this study, a total of 74 (n=74) serum samples collected from horses in four regions of Korea were tested for EqHV RNA using nested RT-PCR. Overall, 14 samples were identified as positive (18.9%) and further analyzed according to gender, age, breed, and region. There were high positive rates in males, young horses, and Thoroughbreds; however, these rates differed regionally. Sequencing of the partial NS3 region of 12 samples and the polyprotein encoding regions of two samples positive for EqHV RNA revealed that the Korean EqHV isolates shared approximately 85.3-99.6% and 97.7-100% homology at the nucleotide and deduced amino acid level, respectively. Phylogenetic analysis revealed that the partial NS3 genes clustered with sequences previously reported as NPHV. Notably, sequences of EqHV detected in horses in the same region showed sequence divergence. The sequences of the polyprotein encoding region of two representative EqHVs shared 83.9% and 95.7% homology with each other at the nucleotide and deduced amino acid level, respectively. Comparison of the sequences of polyprotein encoding regions of Korean EqHV isolates and hepaciviruses from different hosts revealed that the NS3 and NS5B regions were most conserved among hepaciviruses. The results of the present study demonstrate that there is a high positive rate of EqHV in Korea and provide significant information regarding the geographical distribution and genetic variability of Korean EqHV isolates that will help improve global epidemiology of EqHV.

Identification and characterization of avian hepatitis E virus genotype 2 from chickens with hepatitis-splenomegaly syndrome in Korea.

A new avian hepatitis E virus (HEV) GI-B was identified in broiler breeders with hematomas, liver rupture, and splenomegaly, along with excessive abdominal fat, in Korea. Previously, genotype 1 had been identified in avian HEV strains in Korea. Complete sequence analyses revealed that the new avian HEV clustered in genotype 2, which has been identified in the USA and Spain; the GI-B isolate was closely related to the USA prototype avian HEV isolated from a chicken with hepatitis-splenomegaly syndrome. Although some HEV genotypes show a geographical distribution pattern, the discovery of genotype 2 in addition to genotype 1 in Korea suggests that the geographical grouping might be reconsidered. These findings have important implications for understanding the global epidemiology and spread of avian HEV.

Construction of an infectious cDNA clone of genotype 1 avian hepatitis E virus: characterization of its pathogenicity in broiler breeders and demonstration of its utility in studying the role of the hypervariable region in virus replication.

A full-length infectious cDNA clone of the genotype 1 Korean avian hepatitis E virus (avian HEV) (pT11-aHEV-K) was constructed and its infectivity and pathogenicity were investigated in leghorn male hepatoma (LMH) chicken cells and broiler breeders. We demonstrated that capped RNA transcripts from the pT11-aHEV-K clone were translation competent when transfected into LMH cells and infectious when injected intrahepatically into the livers of chickens. Gross and microscopic pathological lesions underpinned the avian HEV infection and helped characterize its pathogenicity in broiler breeder chickens. The avian HEV genome contains a hypervariable region (HVR) in ORF1. To demonstrate the utility of the avian HEV infectious clone, several mutants with various deletions in and beyond the known HVR were derived from the pT11-aHEV-K clone. The HVR-deletion mutants were replication competent in LMH cells, although the deletion mutants extending beyond the known HVR were non-viable. By using the pT11-aHEV-K infectious clone as the backbone, an avian HEV luciferase reporter replicon and HVR-deletion mutant replicons were also generated. The luciferase assay results of the reporter replicon and its mutants support the data obtained from the infectious clone and its derived mutants. To further determine the effect of HVR deletion on virus replication, the capped RNA transcripts from the wild-type pT11-aHEV-K clone and its mutants were injected intrahepatically into chickens. The HVR-deletion mutants that were translation competent in LMH cells displayed in chickens an attenuation phenotype of avian HEV infectivity, suggesting that the avian HEV HVR is important in modulating the virus infectivity and pathogenicity.