Recombinant Type Research Articles

Complete genome sequences of nine double recombinant vaccine-derived novel oral poliovirus type 2 genomes from Nigeria 2023-2024.

We report the complete genome sequences of nine double recombinant vaccine-derived novel oral poliovirus type 2 genomes from acute flaccid paralysis (AFP) cases (n = 3), AFP case contacts (n = 4), and environmental surveillance sampling (n = 2) in Nigeria.

Collaborative Enhancement of Diabetic Wound Healing and Skin Regeneration by Recombinant Human Collagen Hydrogel and hADSCs.

Stem cell-based therapies hold significant promise for chronic wound healing and skin appendages regeneration, but challenges such as limited stem cell lifespan and poor biocompatibility of delivery systems hinder clinical application. In this study, an in situ delivery system for human adipose-derived stem cells is developed (hADSCs) to enhance diabetic wound healing. The system utilizes a photo-crosslinking recombinant human type III collagen (rHCIII) hydrogel to encapsulate hADSCs, termed the hADSCs@rHCIII hydrogel. This hydrogel undergoes local crosslinking at the wound site, establishing a sturdy 3D niche suitable for stem cell function. Consequently, the encapsulated hADSCs exhibit strong attachment and spreading within the hydrogels, maintaining their proliferation, metabolic activity, and viability for up to three weeks in vitro. Importantly, in vivo studies demonstrate that the hADSCs@rHCIII hydrogel achieves significant in situ delivery of stem cells, prolonging their retention within the wound. This ultimately enhances their immunomodulatory capabilities, promotes neovascularization and granulation tissue formation, facilitates matrix remodeling, and accelerates healing in a diabetic mouse wound model. Collectively, these findings highlight the potential of the conveniently-prepared and user-friendly hADSCs@rHCIII hydrogel as a promising therapeutic approach for diabetic wound treatment and in situ skin regeneration.

Immunogenicity of various variants of Ebola and Marburg virus glycoprotein genes in recombinant adenoviral vectors

INTRODUCTION. Marburg and Ebola viruses cause severe haemorrhagic fever in humans and primates. Currently, there are no licensed prophylactic vaccines that can simultaneously prevent the spread or reduce the severity of both diseases caused by these filoviruses. The development of effective prophylactic vaccines requires studies aimed at selecting the most immunogenic forms of protective antigens.AIM. This study aimed to evaluate humoral immune induction in animals after administration of recombinant adenoviral vectors expressing various forms of Ebola and Marburg virus glycoproteins (GPs).MATERIALS AND METHODS. Samples of recombinant human adenovirus type 5 (rAd5) were obtained using homologous recombination in Escherichia coli, growth in HEK293 cells, and purification by CsCl gradient ultracentrifugation. The resulting rAd5 samples were characterised in terms of their identity (PCR and whole-genome sequencing), the concentration of viral particles (fluorescence spectroscopy), and the concentration of infectious viral particles (TCID50 assay). Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the GP-specific IgG titres in the sera of immunised mice.RESULTS. The authors constructed rAd5 samples, and each construct contained an expression cassette with a GP gene form encoding a full-length GP, a GP without the mucin-like domain, or a GP without both the glycan cap and the mucin-like domain. Each of these forms was studied using the GPs of four filoviruses, including Zaire Ebola virus, Sudan Ebola virus, Bundibugyo Ebola virus, and Marburg virus. Neither of the forms had a critical effect on the rAd5 replicative capacity. Three weeks after immunisation, the highest GP-specific IgG production was induced by the rAd5 samples encoding either the full-length GP or the GP without the mucin-like domain. The GP without both the glycan cap and the mucin-like domain was the least immunogenic antigen regardless of the filovirus species.CONCLUSIONS. The most promising constructs for the development of filovirus vaccines based on recombinant adenoviral vectors are the constructs that include the genes encoding the fulllength GP or the GP without the mucin-like domain.

Outbreak of severe acute respiratory infections caused by recombinant human adenovirus type B 7/3 in hospitalized infants from a nursery in Dakar, April 2024

ObjectivesAcute respiratory infections are among the leading cause of mortality in children under 5 years of age worldwide, with most of these deaths due to bronchiolitis and pneumonia. We investigated and analyzed a pediatric outbreak of acute respiratory infections that resulted in the hospitalization of four infants in a nursery in Dakar in late April 2024. MethodsNasopharyngeal specimens were collected from infants and tested for a panel of respiratory pathogens by multiplex real-time reverse transcription–polymerase chain reaction. Subsequently, the positive samples underwent next-generation sequencing for molecular analysis. ResultsHuman adenovirus (HAdV) was the principal etiologic agent detected in hospitalized infants with pneumonia and nearly half (46.7%; seven of 15) of the suspected cases identified during the investigation at the nursery. All the HAdV isolates were classified as being of subgroup B1. Molecular characterization revealed that infants attending the nursery were infected with a recombinant HAdV strain containing an adenovirus serotype 7 penton and serotype 3 hexon and fiber proteins. ConclusionsOur findings reinforce previous evidence that recombination leads to the emergence of new adenovirus strains with epidemic and lethal potential. These results emphasize the need to strengthen surveillance in inpatient settings across the country.

Preparation of recombinant type I collagen (PF-I-80) and its functional characterization and biomedical applications in wound healing

This study evaluates the potential applications of recombinant PF-I-80 protein in regenerative medicine and the treatment of inflammatory diseases, focusing on its effects on cell migration, differentiation, and anti-inflammatory properties. Various in vitro assays were conducted, including scratch assays, Transwell experiments, RT-PCR and Western Blot to analyze gene and protein expression related to differentiation and inflammation, and immunofluorescence staining to observe cellular changes. The results indicated that PF-I-80 significantly promoted cell migration, highlighting its potential in tissue repair and regeneration. It also enhanced cell differentiation, demonstrating its applicability in tissue repair, and showed significant anti-inflammatory effects by reducing the expression of pro-inflammatory cytokines. In animal models, PF-I-80 notably reduced levels of inflammatory factors IL-1β and TNF-α, shortened the inflammatory phase, and accelerated wound healing. Additionally, PF-I-80 increased FGF-2 levels, which promoted the proliferation of endothelial and fibroblast cells and enhanced collagen synthesis. These in vitro and in vivo findings position PF-I-80 as a promising biomaterial for applications in regenerative medicine and inflammatory disease treatment.

Lipopolysaccharide Induces Trained Innate Immune Tolerance in the Heart Through Interferon Signaling in a Model of Stress-Induced Cardiomyopathy.

Although the ability of the heart to adapt to environmental stress has been studied extensively, the molecular and cellular mechanisms responsible for cardioprotection are not yet fully understood. We administered Toll-like receptor (TLR) agonists or a diluent to wild-type mice and assessed their potential to induce cardiac protection against injury from a high intraperitoneal dose of isoproterenol (ISO) administered 7 days later. Cardioprotective effects were analyzed through serum cardiac troponin I levels, immune cell profiling via flow cytometry, echocardiography, and multiomic single-nuclei RNA and ATAC sequencing. Pretreatment with the TLR4 agonist lipopolysaccharide (LPS), but not TLR1/2 or TLR3 agonists, conferred cardioprotection against ISO, as demonstrated by reduced cardiac troponin I leakage, decreased inflammation, preservation of cardiac structure and function, and improved survival. Remarkably, LPS-induced tolerance was reversed by β-glucan treatment. Multiomic analysis showed that LPS-tolerized hearts had greater chromatin accessibility and upregulated gene expression compared to hearts treated with LPS and β-glucan (reverse-tolerized). The LPS tolerance was associated with upregulation of interferon response pathways across various cell types, including cardiac myocytes and stromal cells. Blocking both type 1 and type 2 interferon signaling eliminated LPS-induced tolerance against ISO, while pretreatment with recombinant type 1 and 2 interferons conferred cardiac protection. Multiomic sequencing further revealed enhanced cytoprotective signaling in interferon-treated hearts. Analysis of cell-cell communication networks indicated increased autocrine signaling by cardiac myocytes, as well as greater paracrine signaling between stromal cells and myeloid cells, in LPS-tolerized versus reverse-tolerized hearts. LPS pretreatment confers cardiac protection against ISO-induced injury through TLR4 mediated type 1 and 2 interferon signaling, consistent with trained innate immune tolerance. The observation that LPS-induced protection in cardiac myocytes involves both cell-autonomous and non-cell-autonomous mechanisms underscores the complexity of innate immune tolerance in the heart, warranting further investigation into this cardioprotective phenotype. What is new?: The Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS) confers cardiac protection against isoproterenol-mediated injury in a manner consistent with trained innate immune tolerance, which is reversed by β-glucan treatment.Activation of type 1 and 2 interferon signaling, which is downstream of Toll-like receptor 4, is necessary and sufficient for LPS-induced cardiac protection.LPS-tolerized hearts show heightened autocrine signaling by cardiac myocytes and, to a greater degree, increased cell-cell communication between cardiac myocytes and stromal and myeloid cells compared to reverse-tolerized hearts.What are the clinical implications?: TLR4 and interferon signaling play key roles in the establishment of cardiac protection and LPS-induced trained innate immune tolerance.The protective effects of LPS are mediated by cell-autonomous and non-cell-autonomous mechanisms, suggesting that a deeper understanding of the molecular and cellular signatures of innate immune tolerance is required for the development of targeted approaches to modulate trained innate immunity, and consequently cytoprotection, in the heart.

Advanced Wound Healing and Scar Reduction Using an Innovative Anti-ROS Polysaccharide Hydrogel with Recombinant Human Collagen Type III.

Excessive fibrotic scar formation during skin defect repair poses a formidable challenge, impeding the simultaneous acceleration of wound healing and prevention of scar formation and hindering the restoration of skin integrity and functionality. Drawing inspiration from the structural, compositional, and biological attributes of skin, we developed a hydrogel containing modified recombinant human collagen type III and thiolated hyaluronic acid to address the challenges of regenerating skin appendages and improving the recovery of skin functions after injury by reducing fibrotic scarring. The hydrogel displayed favorable biocompatibility, antioxidant properties, angiogenic potential, and fibroblast migration stimulation in vitro. In a rat full-layer defect model, it reduced inflammation, promoted microvascular formation, and significantly enhanced the wound healing speed and effectiveness. Additionally, by upregulating fibrosis-associated genes, such as TGFB1, it facilitated collagen accumulation and a beneficial balance between type I and type III collagen, potentially expediting skin regeneration and functional recovery. In conclusion, the utilization of rhCol III-HS demonstrated considerable potential as a wound dressing, offering a highly effective strategy for the restoration and rejuvenation of complete skin defects.

Orientation Regulation of Class-switch Recombination in Human B Cells.

We developed a linear amplification-mediated high-throughput genome-wide translocation sequencing method to profile Ig class-switch recombination (CSR) in human B cells in an unbiased and quantitative manner. This enables us to characterize CSR junctions resulting from either deletional recombination or inversion for each Ig class/subclass. Our data showed that more than 90% of CSR junctions detected in peripheral blood in healthy control subjects were due to deletional recombination. We further identified two major CSR junction signatures/patterns in human B cells. Signature 1 consists of recombination junctions resulting from both IgG and IgA switching, with a dominance of Sµ-Sγ junctions (72%) and deletional recombination (87%). Signature 2 is contributed mainly by Sµ-Sα junctions (96%), and these junctions were almost all due to deletional recombination (99%) and were characterized by longer microhomologies. CSR junctions identified in healthy individuals can be assigned to both signatures but with a dominance of signature 1, whereas almost all CSR junctions found in patients with defects in DNA-PKcs or Artemis, two classical nonhomologous end joining (c-NHEJ) factors, align with signature 2. Thus, signature 1 may represent c-NHEJ activity during CSR, whereas signature 2 is associated with microhomology-mediated alternative end joining in the absence of the studied c-NHEJ factors. Our findings suggest that in human B cells, the efficiency of the c-NHEJ machinery and the features of switch regions are crucial for the regulation of CSR orientation. Finally, our high-throughput method can also be applied to study the mechanism of rare types of recombination, such as switching to IgD and locus suicide switching.

Recombinant Marek’s disease virus type 1 provides full protection against H9N2 influenza A virus in chickens

The H9N2 subtype of the avian influenza virus (AIV) poses a significant threat to the poultry industry and human health. Recombinant vaccines are the preferred method of controlling H9N2 AIV, and Marek’s disease virus (MDV) is the ideal vector for recombinant vaccines. During this study, we constructed two recombinant MDV type 1 strains that carry the hemagglutinin (HA) gene of AIV to provide dual protection against both AIV and MDV. To assess the effects of different MDV insertion sites on the protective efficacy of H9N2 AIV, the HA gene of H9N2 AIV was inserted in UL41 and US2 of the MDV type 1 vector backbone to obtain recombinant viruses rMDV-UL41/HA and rMDV-US2/HA, respectively. An indirect immunofluorescence assay showed sustained expression of HA protein in both recombinant viruses. Additionally, the insertion of the HA gene in UL41 and US2 did not affect MDV replication in cell cultures. After immunization of specific pathogen-free chickens, although both the rMDV-UL41/HA and rMDV-US2/HA groups exhibited similar levels of hemagglutination inhibition antibody titers, only the rMDV-UL41/HA group provided complete protection against the H9N2 AIV challenge, and also offered complete protection against challenge with MDV. These results demonstrated that rMDV-UL41/HA could be used as a promising bivalent vaccine strain against both H9N2 avian influenza and Marek’s disease in chickens.

Recombinant humanized type III collagen inhibits ovarian cancer and induces protective anti-tumor immunity by regulating autophagy through GSTP1

Ovarian cancer (OC) is one of the leading causes of death from malignancy in women and lacks safe and efficient treatment. The novel biomaterial, recombinant humanized collagen type III (rhCOLIII), has been reported to have various biological functions, but its role in OC is unclear. This study aimed to reveal the function and mechanism of action of rhCOLIII in OC. We developed an injectable recombinant human collagen (rhCOL)-derived material with a molecular weight of 45 kDa, with a stable triple helix structure, high biocompatibility, water solubility and biosafety. The anti-tumor activity of rhCOLIII was comprehensively evaluated through in vitro and in vivo experiments. In vitro, our results showed that rhCOLIII inhibited the proliferation, migration, and invasion of ovarian cancer cells (OCCs), and induced apoptosis. In addition, rhCOLIII not only inhibited autophagy of OCCs but also increased the expression of MHC-1 molecule within OCCs. To further elucidate the mechanism of rhCOLIII in OC, we conducted joint analysis of RNA-Seq and proteomics, and found that rhCOLIII exerted anti-tumor function and autophagy inhibition by downregulating Glutathione S-transferase P1 (GSTP1). Furthermore, various rescue experiments were designed to demonstrate that rhCOLIII suppressed autophagy and proliferation of OCCs by mediating GSTP1. In vivo, we found that rhCOLIII could inhibit tumor growth and promote CD8+ T cell infiltration. Our results indicate that rhCOLIII has great anti-tumor potential activity in OC, and induces protective anti-tumor immunity by regulating autophagy through GSTP1. These findings illustrate the potential therapeutic prospects of rhCOLIII for OC treatment.

Glaesserella parasuis serotype 4 exploits fibronectin via RlpA for tracheal colonization following porcine circovirus type 2 infection.

Porcine circovirus type 2 (PCV2) often causes disease through coinfection with other bacterial pathogens, including Glaesserella parasuis (G. parasuis), which causes high morbidity and mortality, but the role played by PCV2 and bacterial and host factors contributing to this process have not been defined. Bacterial attachment is assumed to occur via specific receptor-ligand interactions between adhesins on the bacterial cell and host proteins adsorbed to the implant surface. Mass spectrometry (MS) analysis of PCV2-infected swine tracheal epithelial cells (STEC) revealed that the expression of Extracellular matrix protein (ECM) Fibronectin (Fn) increased significantly on the infected cells surface. Importantly, efficient G. parasuis serotype 4 (GPS4) adherence to STECs was imparted by interactions with Fn. Furthermore, abrogation of adherence was gained by genetic knockout of Fn, Fn and Integrin β1 antibody blocking. Fn is frequently exploited as a receptor for bacterial pathogens. To explore the GPS4 adhesin that interacts with Fn, recombinant Fn N-terminal type I and type II domains were incubated with GPS4, and the interacting proteins were pulled down for MS analysis. Here, we show that rare lipoprotein A (RlpA) directly interacts with host Fibronectin mediating GPS4 adhesion. Finally, we found that PCV2-induced Fibronectin expression and adherence of GPS4 were prevented significantly by TGF-β signaling pathway inhibitor SB431542. Our data suggest the RlpA-Fn interaction to be a potentially promising novel therapeutic target to combat PCV2 and GPS4 coinfection.

Macrophage M2 polarisation empowered reduction of abdominal adhesions via recombinant human type III collagen

Macrophage M2 polarisation empowered reduction of abdominal adhesions via recombinant human type III collagen

Tailored extracellular matrix-mimetic coating facilitates reendothelialization and tissue healing of cardiac occluders

Minimally invasive transcatheter interventional therapy utilizing cardiac occluders represents the primary approach for addressing congenital heart defects and left atrial appendage (LAA) thrombosis. However, incomplete endothelialization and delayed tissue healing after occluder implantation collectively compromise clinical efficacy. In this study, we have customized a recombinant humanized collagen type I (rhCol I) and developed an rhCol I-based extracellular matrix (ECM)-mimetic coating. The innovative coating integrates metal-phenolic networks with anticoagulation and anti-inflammatory functions as a weak cross-linker, combining them with specifically engineered rhCol I that exhibits high cell adhesion activity and elicits a low inflammatory response. The amalgamation, driven by multiple forces, effectively serves to functionalize implantable materials, thereby responding positively to the microenvironment following occluder implantation. Experimental findings substantiate the coating's ability to sustain a prolonged anticoagulant effect, enhance the functionality of endothelial cells and cardiomyocyte, and modulate inflammatory responses by polarizing inflammatory cells into an anti-inflammatory phenotype. Notably, occluder implantation in a canine model confirms that the coating expedites reendothelialization process and promotes tissue healing. Collectively, this tailored ECM-mimetic coating presents a promising surface modification strategy for improving the clinical efficacy of cardiac occluders.

Isolation and identification of a novel porcine-related recombinant mammalian orthoreovirus type 3 strain from cattle in Guangxi Province, China.

The Mammalian orthoreovirus (MRV) infects various mammals, including humans, and is linked to gastrointestinal, respiratory, and neurological diseases. A recent outbreak in Liuzhou, Guangxi, China, led to the isolation of a new MRV strain, GXLZ2301, from fecal samples. This strain replicates in multiple cell lines and forms lattice-like structures. Infected cells exhibit single-cell death and syncytia formation. The virus's titers peaked at 107.2 TCID50/0.1 mL in PK-15 and BHK cells, with the lowest at 103.88 TCID50/0.1 mL in A549 cells. Electron microscopy showed no envelope with a diameter of about 70 nm. Genetic analysis revealed GXLZ2301 as a recombinant strain with gene segments from humans, cows, and pigs, similar to type 3 MRV strains from Italy (2015-2016). Pathogenicity tests indicated that while the bovine MRV strain did not cause clinical symptoms in mice, it caused significant damage to the gut, lungs, liver, kidneys, and brain. The emergence of this MRV strain may pose a threat to the health of animals and humans, and it is recommended that its epidemiology and recombination be closely monitored.

Recombinant human adenovirus type 5 promotes anti-tumor immunity via inducing pyroptosis in tumor endothelial cells.

Recombinant human type 5 adenovirus (H101) is an oncolytic virus used to treat nasopharyngeal carcinoma. Owing to the deletion of the E1B-55kD and E3 regions, H101 is believed to selectively inhibit nasopharyngeal carcinoma. Whether H101 inhibits other type of tumors via different mechanisms remains unclear. In this study we investigated the effects of H101 on melanomas. We established B16F10 melanoma xenograft mouse model, and treated the mice with H101 (1 × 108 TCID50) via intratumoral injection for five consecutive days. We found that H101 treatment significantly inhibited B16F10 melanoma growth in the mice. H101 treatment significantly increased the infiltration of CD8+ T cells and reduced the proportion of M2-type macrophages. We demonstrated that H101 exhibited low cytotoxicity against B16F10 cells, but the endothelial cells were more sensitive to H101 treatment. H101 induced endothelial cell pyroptosis in a caspase-1/GSDMD-dependent manner. Furthermore, we showed that the combination of H101 with the immune checkpoint inhibitor PD-L1 antibody (10 mg/kg, i.p., every three days for three times) exerted synergic suppression on B16F10 tumor growth in the mice. This study demonstrates that, in addition to oncolysis, H101 inhibits melanoma growth by promoting anti-tumor immunity and inducing pyroptosis of vascular endothelial cells.

Optimizing small-diameter vascular grafts: Harnessing the power of recombinant human type III collagen (rhCOLIII) for enhanced antiplatelet and endothelialization performance

Small-diameter vascular grafts hold great promise as potential substitutes for coronary and peripheral arteries. However, their clinical availability is hindered by thrombogenicity and intimal hyperplasia. Herein, bilayer vascular grafts with enhanced antithrombogenicity and endothelialization were developed by two-step electrospinning technology. First, the well-designed recombinant human type III collagen (rhCOLIII), featuring numerous triplets that promote cell adhesion while excluding sequences prone to platelet adhesion and activation, was composited with poly(L-lactide-co-ε-caprolactone) (PLCL) to create a bioactive inner layer. Afterward, a pure PLCL outer layer with exceptional elasticity was constructed to provide mechanical support. In vitro antiplatelet and cytocompatibility experiments revealed that the graft containing 60% rhCOLIII exhibited almost no platelet adhesion, while the number of adhered endothelial cells increased approximately 20 times compared to pure PLCL. Furthermore, Beagle dog femoral artery implantation models demonstrated that the rhCOLIII-modified grafts underwent endothelialization within three months, contributing to the patency of grafts. The potential mechanism for enhanced endothelialization by rhCOLIII was investigated through transcriptome sequencing and verified by an integrated analysis of gene and protein expression. The cell-affinity units, Gly-Glu-Arg (GER) and Gly-Glu-Lys (GEK) triplets, present in rhCOLIII contribute to initial adhesion of endothelial cells. Following adhesion, they may upregulate the expression of integrins αVβ8 on the cell surface, thereby further enhancing cell adhesion. Subsequently, the FAK/PI3K/AKT pathway within endothelial cells may also be activated to promote cell proliferation.

Stepwise co-assembled biomimetic hydrogel with antibacterial, angiogenesis, and tissue regeneration acceleration for diabetic wound healing

Bacterial infections and inadequate tissue regeneration capacity are prevalent issues in diabetic wounds, impeding the healing process. To solve these problems, a biomimetic hydrogel combined with bacterial cellulose (BC), recombinant human collagen type III (RHC), and ε-poly-L-Lysine (EPL) is fabricated by stepwise co-assembly technology. Owing to the RHC and EPL modifications of BC, the biomimetic hydrogel exhibited antibacterial effects and promoted fibroblast proliferation and angiogenesis, which accelerated the healing of diabetic wounds. Biomimetic hydrogels exhibit good mechanical properties and excellent water absorption, that can protect wounds and provide a moist environment. In addition, in vitro studies have shown that the hydrogels exhibit excellent antibacterial activity and biocompatibility. In vivo studies on diabetic wound healing have shown that biomimetic hydrogels can promote angiogenesis, accelerate collagen deposition, and re-epithelialize wound sites to promote wound healing. This study provides a new and promising strategy for the treatment of diabetic wounds.

Insights into non-crossover recombination from long-read sperm sequencing.

Meiotic recombination is a fundamental process that generates genetic diversity by creating new combinations of existing alleles. Although human crossovers have been studied at the pedigree, population and single-cell level, the more frequent non-crossover events that lead to gene conversion are harder to study, particularly at the individual level. Here we show that single high-fidelity long sequencing reads from sperm can capture both crossovers and non-crossovers, allowing effectively arbitrary sample sizes for analysis from one male. Using fifteen sperm samples from thirteen donors we demonstrate variation between and within donors for the rates of different types of recombination. Intriguingly, we observe a tendency for non-crossover gene conversions to occur upstream of nearby PRDM9 binding sites, whereas crossover locations have a slight downstream bias. We further provide evidence for two distinct non-crossover processes. One gives rise to the vast majority of non-crossovers with mean conversion tract length under 50bp, which we suggest is an outcome of standard PRDM9-induced meiotic recombination. In contrast ~2% of non-crossovers have much longer mean tract length, and potentially originate from the same process as complex events with more than two haplotype switches, which is not associated with PRDM9 binding sites and is also seen in somatic cells.

Recombination and selection trajectory of the monkeypox virus during its adaptation in the human population.

Monkeypox, caused by the monkeypox virus (MPXV), was historically confined to West and Central Africa but has now spread globally. Recombination and selection play crucial roles in the evolutionary adaptation of MPXV; however, the evolution of MPXV and its relationship with the recent, ground-breaking monkeypox epidemic remains poorly understood. To gain insights into the evolutionary dynamics of MPXV, comprehensive in silico recombination and selection analyses were conducted based on MPXV whole genome sequence data. Three types of recombination were identified: five ancestor-sharing interspecies recombination events, six specific interspecies recombination events and four intraspecies recombination events. The results highlight the prevalent occurrence of recombination in MPXV, with 73.3% occurring in variable regions of the genome. Selection analysis was performed from three dimensions: proteins around recombination regions, proteins from recombinant ancestors and MPXV branches, and whole-genome gene analysis. Results revealed 2 and 7 proteins under positive selection in the first two dimensions, respectively. These proteins are mainly involved in infection immunity, apoptosis regulation and viral virulence. Whole-genome analysis detected 25 genes under positive selection, mainly associated with immune response and viral regulation. Understanding their evolutionary patterns will help predict and prevent cross-species transmission, zoonotic outbreaks and potential human epidemics.

Inhibition of FoxO1 ameliorates hepatic steatosis and hepatitis in nonalcoholic steatohepatitis mice through regulation of gut microbiota.

We aimed to investigate the role of forkhead box O1 (FoxO1) inhibitor AS1842856 (AS) in nonalcoholic steatohepatitis (NASH) mice and the potential mechanisms. Mice were given methionine-choline-sufficient (MCS), or methionine- and choline-deficient (MCD) diet for 5 weeks, along with AS (60 mg/kg) or vehicle gavage treatment (0.2 mL/day). Body and liver weight, serum triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), alanine aminotransferase (ALT), aspartate aminotransferase (AST), fasting glucose and insulin levels were measured. Liver macrophage infiltration and ileal ZO-1 protein expression were also detected. Interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α, sterol regulatory element binding protein (SREBP)-1c, phosphoenolpyruvate carboxykinase (PEPCK), and glucose-6-phosphatase (G6Pase), α-smooth muscle actin (SMA), recombinant collagen type III α1 (Col3a1), and connective tissue growth factor (Ctgf) expressions were measured. Stool samples were collected for 16S rDNA sequencing. Compared to the MCD group, AS attenuated liver weight, reduced serum TG, ALT, and AST levels, increased HDL-C levels, mitigated hepatic steatosis, decreased macrophage infiltration, and augmented ileal ZO-1 proteins in NASH mice. It also reduced the levels of IL-6, IL-1β, and TNF-α, alongside with the Srebp-1c mRNA expression. However, no significant effects on Pepck, G6Pase, α-SMA, Col3a1, or Ctgf were observed. Furthermore, AS promoted diversity and altered gut microbiota composition in NASH mice, causing increased beneficial bacteria like Akkermansia muciniphila, Parabacteroides distasonis, and Prevotellamassilia, which were associated with metabolic functions. FoxO1 inhibitor AS ameliorated hepatic steatosis, inflammation, and intestinal dysbiosis in NASH mice, making it a potentially promising treatment for NASH.