Guanylate-binding protein 1 inhibits Hantaan virus infection by restricting virus entry.

Hantaan virus (HTNV) infection can cause hemorrhagic fever with renal syndrome (HFRS) in humans, and currently, there are no long-standing protective vaccines or specific antivirals available. Guanylate-binding protein 1 (GBP1) is an interferon-stimulated gene that defends against various pathogen infections. However, the function of GBP1 in HTNV infection remains unknown. Here, we describe how GBP1 prevents HTNV infection by obstructing virus entry. We found that HTNV infection induced GBP1 expression and that overexpression of GBP1 inhibited HTNV infection, while knockout of GBP1 had the opposite effect. Interestingly, GBP1 did not affect interferon (IFN) signaling during HTNV infection. Instead, GBP1 prevented HTNV from entering cells through clathrin-mediated endocytosis (CME). We also discovered that GBP1 specifically interacted with actin but not dynamin 2 (DNM2) and made it difficult for DNM2 to be recruited by actin, which may account for the suppression of CME during HTNV infection. These findings establish an antiviral role for GBP1 in inhibiting HTNV infection and help us better understand how GBP1 regulates HTNV entry and could potentially aid in developing treatments for this virus.

Bomidin: An Optimized Antimicrobial Peptide With Broad Antiviral Activity Against Enveloped Viruses.

The rapid evolution of highly infectious pathogens is a major threat to global public health. In the front line of defense against bacteria, fungi, and viruses, antimicrobial peptides (AMPs) are naturally produced by all living organisms and offer new possibilities for next-generation antibiotic development. However, the low yields and difficulties in the extraction and purification of AMPs have hindered their industry and scientific research applications. To overcome these barriers, we enabled high expression of bomidin, a commercial recombinant AMP based upon bovine myeloid antimicrobial peptide-27. This novel AMP, which can be expressed in Escherichia coli by adding methionine to the bomidin sequence, can be produced in bulk and is more biologically active than chemically synthesized AMPs. We verified the function of bomidin against a variety of bacteria and enveloped viruses, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), herpes simplex virus (HSV), dengue virus (DENV), and chikungunya virus (CHIKV). Furthermore, based on the molecular modeling of bomidin and membrane lipids, we elucidated the possible mechanism by which bomidin disrupts bacterial and viral membranes. Thus, we obtained a novel AMP with an optimized, efficient heterologous expression system for potential therapeutic application against a wide range of life-threatening pathogens.

[Construction of lentivirus plasmid pCDH-NLRX1 and stable expression of NLRX1 in A549 cells].

Objective To construct nucleotide-binding oligomerization domain-like receptors family member X1 (NLRX1) lentivirus plasmid and stable NLRX1-overexpressing A549 cell line. Methods Full-length cDNA encoding human NLRX1 was amplified from pCMV3-NLRX1 plasmid and then was inserted into pCDH-CMV-MCS-EF1-Puro vector to obtain NLRX1-overexpressing plasmid pCDH-NLRX1. pCDH-NLRX1 lentivirus particles were obtained by co-transfecting pCDH-NLRX1 with packaging plasmids (pMD2 and pAX2) into HEK293T cells. A549 cells were infected with concentrated pCDH-NLRX1 lentivirus particles and then were screened by puromycin to obtain stable NLRX1-overexpressed A549 cell line. The mRNA transcription and protein expression of NLRX1 were detected by real-time quantitative PCR, Western blot analysis and immunofluorescence. Results The lentivirus plasmid pCDH-NLRX1 was successfully constructed. After pCDH-NLRX1 and packaging plasmids were co-transfected into HEK293T cells, we obtained NLRX1 lentivirus particles with the titer of 1×105 TU/mL. After A549 cells were infected with lentivirus particles and screened by puromycin, a stable over-expression cell line of NLRX1 was obtained. NLRX1 was obviously expressed in the lentivirus-infected A549 cells and its mRNA and protein levels significantly increased. Conclusion NLRX1 lentivirus plasmid and stable NLRX1-overexpressing A549 cell line have been successfully constructed.

Middle- and high-molecular weight adiponectin levels in relation to nonalcoholic fatty liver disease.

OBJECTIVE: Adiponectin (APN) circulates as high-molecular weight (HMW), medium-molecular weight (MMW), and low-molecular weight (LMW) forms. Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease. Currently, the role of LMW, MMW, and HMW APN remains largely unclear in NAFLD. METHODS: We examined the variation of these forms and analyzed the related clinical characteristics in NAFLD. A total of 63 male NAFLD patients (mean age: 43.00 ± 6.10 years) and 70 healthy male subjects (mean age: 42.53 ± 7.98 years) were included in the study. Total APN and other clinical characteristics were measured. The changes in HMW, MMW, and LMW APN were determined in NAFLD patients and NAFLD patients on a high-fat diet, and the association between the groups was further analyzed. RESULTS: Decreased levels of total APN and three APN isoforms were found in NAFLD. Significantly decreased levels of HMW (P < .01) and MMW (P < .001) were observed in NAFLD of high-fat diet patients. In NAFLD patients, height (R = -.270, P = .032) and N-epsilon-(carboxymethyl) lysine (R = -.259, P = .040) significantly correlated with total APN. HMW APN was significantly associated with fasting plasma glucose (R = .350, P = .016), alanine aminotransferase (R = -.321, P = .029), and aspartate aminotransferase (R = -.295, P = .045). Additionally, MMW APN was significantly associated with total cholesterol (R = .357, P = .014) and high-density lipoprotein (R = .556, P < .0001). Low-density lipoprotein (R = -.283, P = .054) was also clearly associated with LMW APN in NAFLD patients. CONCLUSION: These results suggest that HMW and MMW APN may be involved in the pathogenesis and progression of NAFLD.

Double-helix PnLin chains: novel potential nonlinear optical materials.

The structures, circular dichroism (CD) spectra and nonlinear optical (NLO) responses of a series of inorganic double-helix chains, PnLin (n = 6-12), have been investigated using the quantum chemistry method. P-P and P-Li interactions play a major role in stabilizing double-helix chains. The distinctive CD spectra of the double-helix frameworks (namely, a sharp negative CD band at short-wavelength region and a positive CD band at long-wavelength region) become obvious with increasing number of PLi units. The NLO response augments with the length of the double-helix chains, and the contribution of the axial component along the chain direction gradually becomes crucial simultaneously. Synergistic effects, a decrease of crucial electronic transition energies and charge transfer excitation give rise to enhanced NLO responses. In particular, the electronic transitions from the highest occupied molecular orbital to the lowest unoccupied molecular orbital make significant contributions not only to the positive CD bands in the long-wavelength region, but also to the NLO responses of the double-helix PnLin (n = 6-12) chains.