Abstract:

Abstract:Dengue fever is a mosquito-borne disease prevalent in tropical and subtropical regions, with its prevalence expanding due to increased global travel. The dengue virus, the causative agent of dengue fever, often co-circulates in the form of four distinct serotypes. Cross-reactive antibodies generated during a primary infection pose a significant risk during secondary infections with different serotypes, and fully protective vaccines and antiviral drugs are yet to be developed. Over the past decade, advances in antibody technology have led to the isolation of numerous monoclonal antibodies against dengue virus, with their neutralizing epitopes elucidated through structure-based analyses. This review highlights the key epitopes associated with neutralizing antibodies against dengue virus and discusses their potential applications in vaccine design and therapeutic antibody development. This review helps systematically summarize the progress in dengue virus neutralizing antibody research, providing a theoretical foundation and technical guidance for the development of novel vaccines and antibody therapeutics.

Abstract:Nanobodies (Nbs), the unique single-domain antibodies discovered in the species of Camelidae and sharks, are also known as the variable domain of the heavy chain of heavy-chain antibody (VHH). They offer strong antigen targeting and binding capabilities and overcome the drawbacks such as large size, low stability, high immunogenicity, and slow clearance of conventional antibodies. Nbs can be boosted by bioconjugation with toxins, enzymes, radioactive nucleotides, fluorophores, and other functional groups, demonstrating potential applications in the diagnosis and treatment of human and animal diseases. This article introduces the structures and characteristics of Nbs, the construction and screening of Nb libraries, and the strategies for affinity maturation and then reviews the current applications of Nbs in diagnosis and treatment, providing a reference for the development of diagnostic reagents and clinical therapies for infectious diseases.

Abstract:Lipid nanoparticles serve as a promising drug delivery system due to the good biocompatibility, non-immunogenicity, and high drug loading efficiency. However, unmodified lipid nanoparticles have limitations such as poor stability, easy hydrolysis, and rapid removal. To overcome these shortcomings, researchers have developed peptide modification, antibody modification, ligand modification, nucleic acid aptamer modification, and polysaccharide modification for lipid nanoparticles. Polysaccharides are a class of natural polymers, and the polysaccharide-modified lipid nanoparticles exhibit good biocompatibility, precise targeting, and low toxicity. Therefore, polysaccharide-modified lipid nanoparticles demonstrate great potential in clinical treatment. This review summarizes the preparation and application of polysaccharide-modified lipid nanoparticles, aiming to provide a reference for further research and development of new lipid nanoparticles.

Abstract:Ten-eleven translocation 1 (TET1) protein is an alpha-ketoglutaric acid (α-KG) and Fe²⁺-dependent dioxygenase. It plays a role in the active demethylation of DNA by hydroxylation of 5-methyl-cytosine (5-mC) to 5-hydroxymethyl-cytosine (5-hmC). Ten-eleven translocation 1 (TET1) protein is involved in maintaining genome methylation homeostasis and epigenetic regulation. Abnormally expressed TET1 and 5-mC oxidative derivatives have become potential markers in various biological and pathological processes and a research focus in the fields of embryonic development and malignant tumors. This paper introduces the structure and demethylation mechanism of TET1, reviews the research status of epigenetic regulation by TET1 in embryonic development, immune responses, stem cell regulation, cancer progression, and nervous system development, and briefs the upstream regulatory mechanism of TET1, hoping to provide new inspirations for further research in related fields.

Abstract:The fiber type transition of skeletal muscle is an intricate and essential physiological process in the body, significantly influencing both the function and metabolism of skeletal muscle. This phenomenon is not only affected by external environmental changes but also intricately regulated by internal physiological mechanisms. Therefore, exploring the physiological process of muscle fiber type transition holds considerable significance for the treatment of human neuromuscular disorders and the improvement of meat quality in livestock and poultry. It has been discovered that the cytokines secreted by skeletal muscle, i.e., myokines, play a role in the fiber type transition of skeletal muscle. Myokines mainly act on skeletal muscle in autocrine and paracrine forms to participate in signal transduction and regulate the fiber type transition of skeletal muscle. This paper reviews the functional differences among various muscle fiber types, expounds the effects and mechanisms of myokines in regulating the transition processes of these fiber types, and prospects the future research directions in this field. This review is expected to provide theoretical support for enhancing the meat quality of livestock and poultry and treating skeletal muscle-related diseases.

Abstract:Epigallocatechin gallate (EGCG), the predominant polyphenol in green tea, exerts a spectrum of physiological activities, including antioxidant, anticancer, and anti-inflammatory effects. Emerging research underscores the significance of EGCG in modulating oocyte aging. EGCG can enhance antioxidant defenses, improve mitochondrial functions, and inhibit apoptotic pathways, thereby retarding the aging of oocytes. This review delineates the main molecular features of EGCG and expounds its regulatory mechanisms concerning oocyte aging, enriching the knowledge on the role of EGCG in the amelioration of oocyte aging.

Abstract:Antimicrobial peptides (AMPs) are small molecular peptides widely existing in the innate immunity of organisms, serving as the first line of defense. Natural AMPs possess various biological activities and are difficult to develop drug resistance. However, they are easily broken down by digestive enzymes in the body. In recent years, increasing methods have been reported to enhance the stability of AMPs, including incorporation of unnatural amino acids, chemical modifications, strategic avoidance of enzyme cleavage sites, cyclization, and nano peptide design. This review summarizes the methods for improving the stability of AMPs against protease degradation, aiming to provide references for further research in this field.

Abstract:Mastoparans (MP), a class of α-helix cationic insect-derived antimicrobial peptides, have a broad spectrum of biological activities including inhibiting bacteria, fungi, viruses, and parasites. Amino acid substitution, peptide modification, peptide chain cyclization, and dosage form modification can enhance the biological activities and target and reduce the toxicity of mastoparans. In this review, we summarize the structure, biological function and modification methods of mastoparans, and prospect the development of antibacterial drugs based on mastoparans, so as to provide reference for the research of mastoparans as a new antibacterial drug.

Abstract:Argonaute proteins are active throughout the lifetime in a variety of organisms and they bind to small RNAs (sRNAs) to regulate gene expression. The Argonaute proteins of vertebrates can be classified into two clades: the Ago clade and the Piwi clade. Both clades have N, L1, L2, PAZ, MID and PIWI domains. The N domain is involved in the loading of sRNAs. L1 and L2 domains facilitate the linking between domains. The PAZ and MID domains exert functions by anchoring sRNAs. The PIWI domain of some Argonaute proteins has RNase H-like structure and exerts the endonuclease function. Ago proteins regulate gene expression at transcriptional and post-transcriptional levels. Piwi proteins mainly exist in the germ cells, silencing transposons in different ways to keep genome integrality and regulating gene expression. In recent years, great progress has been made in Argonaute proteins in terms of the crystal structures, functions, and expression patterns. By reviewing the relevant studies, we elaborate on the structures, sRNA dependence, gene expression regulation, and biological roles of the Ago and Piwi proteins in vertebrates, aiming to clarify the roles of Argonaute proteins in epigenetic regulation and provide a reference for further research and application of these proteins.

Abstract:Bluetongue virus (BTV) usually infects sheep, cattle, deer and other domesticated and wild ruminants through the bite of the vector insects, Culicoide, causing bluetongue (BT). BT in subtropical and even temperate regions poses a serious threat to the development and international trade of the livestock industry. This article introduced the structure and cellular invasion, and summarized the mechanisms of anti-BTV immune response of host cells and antagonism of host cell innate immune response by the non-structural proteins (e.g., NS3 and NS4) and structural proteins (e.g., VP3 and VP4) of BTV. This review provided a basis for understanding the antagonism mechanisms of BTV against the interferon (IFN) immune response in the host cell and the pathogenesis of BTV as well as for developing novel vaccines against this virus.

Abstract:Embryo implantation involves a complex interaction between the embryo and the endometrium of the mother, the study of which faces a variety of problems. The modeling of endometrial epithelial organoids and endometrial assembloids provides a new way to study the process of embryo implantation in vitro. This paper summarized the latest research progress in embryo implantation, the regulation mechanism of endometrial receptivity by estrogen- progesterone coordination and embryo-derived signals, the establishment of endometrial organoids, and the development and application of endometrial assembloids in the research on mother-embryo interaction, providing new strategies for studying the communication between embryo and maternal uterus during implantation.

Abstract:The rapid development of modern industries is accompanied with the aggravating water heavy metal pollution, which poses a potential threat to the aquatic environment and the health of local populations. As an efficient and economical adsorbent, biochar demonstrates the adsorption capacity for heavy metal ions and its adsorption capacity is significantly enhanced after modification. Therefore, biochar can effectively mitigate environmental pollution. By reviewing the existing studies, we summarize the modification methods of biochar, compare the advantages and disadvantages of physical, biological, and chemical modification methods, analyze the effects of modification on the adsorption capacity of biochar for heavy metal ions, and expound the modification mechanism of biochar. On this basis, this article puts forward the future research directions of the application of biochar in treating coexisting pollutants, aiming to provide a reference for the application of biochar in the purification of heavy metal-containing wastewater.

Abstract:Arsenic (As) is a common toxic pollution element. The microorganism-mediated transformation of arsenic forms is an important part in the biogeochemical cycle of As. In the various microbial metabolic processes involving As, the coupling reduction of As has a great impact on the environment and is a process that is easily overlooked. From the biogeochemical cycle of As, this review introduces the microorganism-mediated methane oxidation, anaerobic ammonium oxidation, and iron (Fe)-sulfur (S) oxidation coupled with As reduction. Organic matter, pH, and redox potential are the main factors affecting the coupling reduction. After the coupling reduction, the toxicity and migration of As are greatly enhanced, which may increase the risk of As pollution. Therefore, it is of great significance to clarify the influences of carbon, nitrogen, Fe, S and other elements on the coupling process and explore more microbial processes coupled with As reduction for the prevention and control of As pollution.

Abstract:The aim of this study was to compare the immune responses of C57BL/6 mice immunized with two pathogens, foot-and-mouth disease virus (FMDV) and Senecavirus A (SVA), and to provide clues for revealing the regulatory mechanisms of acquired immunity. Inactivated and purified FMDV and SVA antigens were used to immunize C57BL/6 mice respectively, and the mice immunized with PBS were taken as the control. The percentages of Th1 and Th2 cells in the spleen lymphocytes of mice in each group were analyzed by flow cytometry at 14 and 28 days after immunization. RNA-Seq was performed for the spleen. Mouse macrophages were stimulated with the antigens in vitro to examine the expression of the differentially expressed genes (DEGs) screened out. The results showed that 14 days after immunization, there was no significant difference in the magnitude of the Th1/Th2 immune response elicited by the FMDV and SVA antigens. After 28 days, the magnitudes of the Th1 and Th2 immune responses elicited by the SVA antigen were higher than those elicited by the FMDV antigen. RNA-Seq revealed two common DEGs, Rsad2 and Tspan8, between the two immunization groups, which indicated that the two genes may be involved in the activation of the Th1/Th2 immune responses by FMDV and SVA antigens. FMDV and SVA antigens stimulated macrophages to secrete interleukin (IL)-12 and IL-33 in vitro, and the expression of Tspan8 and Rsad2 was consistent with the RNA-Seq results. The expression of Rsad2 was regulated by type I interferons (IFNα, IFNβ). In this study, we obtained the DEGs involved in the immune responses to the two antigens in mouse spleen, which provides a molecular basis for investigating the immune response mechanisms induced by FMDV and SVA.

Abstract:This study developed ferritin-based nanoparticles carrying the African swine fever virus (ASFV) p30 protein and evaluated their immunogenicity, aiming to provide an experimental basis for the research on nanoparticle vaccines against ASFV. Initially, the gene sequences encoding the p30 protein and SpyTag were fused and inserted into the pCold-I vector to create the pCold-p30 plasmid. The gene sequences encoding SpyCatcher and ferritin were fused and then inserted into the pET-28a(+) vector to produce the pET-F-np plasmid. Both plasmids were expressed in Escherichia coli upon induction. Subsequently, the affinity chromatography-purified p30 protein was conjugated with ferritin in vitro, and the p30-ferritin (F-p30) nanoparticles were purified by size-exclusion chromatography. The morphology and structural integrity of F-p30 nanoparticles were examined by a particle size analyzer and transmission electron microscopy. Mice were immunized with F-p30 nanoparticles, and the humoral and cellular immune responses were assessed. The results showed that F-p30 nanoparticles were successfully prepared, with the particle size of approximately 20 nm. F-p30 nanoparticles were efficiently internalized by bone marrow-derived dendritic cells (BMDCs) cells in vitro. Compared with the p30 protein alone, F-p30 nanoparticles induced elevated levels of specific antibodies and cytokines in mice and stimulated the proliferation of follicular helper T cell (T_FH) and germinal center B cell (GCB) in lymph nodes as well as CD4⁺ and CD8⁺ T cells in the spleen. In conclusion, we successfully prepared F-p30 nanoparticles which significantly enhanced the immunogenicity of p30 protein, giving insights into the development of vaccines against ASFV.

Abstract:To construct a recombinant Bacillus subtilis strain expressing SpaA and CbpB of Erysipelothrix rhusiopathiae for oral administration, we constructed the recombinant plasmid pDG1730-CBJA by fusion PCR and seamless cloning. The plasmid was introduced into B. subtilis KC strain by natural transformation, and the recombinant strain KC-spaA-cbpB was screened out on the plate containing spectinomycin (spe^r) and confirmed by PCR and starch degradation test. The SpaA and CbpB expressed by KC-spaA-cbpB were detected by Western blotting and indirect immunofluorescence assay, and the genetic stability of the recombinant strain in mice was determined. The plasmid pMAD-∆spe^r with knockout of spe^r was constructed and transformed into KC-spaA-cbpB. The spe^r-deleted mutant strain KC-spaA-cbpB::∆spe^r was screened and identified, and its immunogenicity in a mouse model was evaluated by oral immunization. The results showed that the recombinant strain KC-spaA-cbpB was stable in mice, expressing SpaA on the cell surface and CbpB on the spore surface. KC-spaA-cbpB::∆spe^r expressed SpaA and CbpB. The mice vaccinated with the spores of KC-spaA-cbpB::∆spe^r had higher levels of SpaA and CbpB-specific IgG in the serum that those vaccinated with the wild-type spores 42 days after vaccination by gavage (P<0.01). The protective rate of mice immunized with the recombinant spores was 67.5%. The results indicated that a recombinant B. subtilis strain expressing SpaA and CbpB of E. rhusiopathiae was successfully constructed, and the recombinant strain laid a foundation for the development of oral live vector vaccines for swine erysipelas.

Abstract:To screen and identify the key host proteins interacting with the non-structural protein 15 (Nsp15) of porcine epidemic diarrhea virus (PEDV). The IP/pull-down assay and mass spectrometry were employed to screen and identify the host proteins interacting with Nsp15. The interaction between the host protein and Nsp15 was studied by co-immunoprecipitation and laser scanning confocal microscopy. Finally, Western blotting and RT-qPCR were employed to examine the interaction between SLC25a3 and PEDV. The recombinant eukaryotic expression vector pcDNA3.1(+)-Flag-Nsp15 was successfully constructed, and the host protein SLC25a3 interacting with PEDV Nsp15 was screened out. An interaction existed between SLC25a3 and Nsp15, and SLC25a3 significantly inhibited PEDV replication in a dose-dependent manner. SLC25a3 inhibits PEDV replication. The results of this study provide a basis for deciphering the role and mechanism of SLC25a3 in the host immune response to PEDV infection.

Abstract:This work aims to explore the effect of glycolysis on the replication of porcine reproductive and respiratory syndrome virus (PRRSV) in porcine alveolar macrophages (PAMs). The changes of glucose metabolism, PRRSV protein levels, PRRSV titers, and the relative expression levels of genes and proteins in PAMs were analyzed by ELISA, qPCR, virus titration, and Western blotting after PRRSV infection. The effect of hypoxia-inducible factor-1α (HIF-1α) on PRRSV replication was subsequently assessed by specific siRNAs targeting to HIF-1α. The results showed that PRRSV infection enhanced glycolysis, elevated the levels of glucose uptake and lactate in the supernatant (P<0.05 and 0.01, respectively), reduced ATP production (P<0.05), and up-regulated the expression of hexokinase 2 (HK2), 6-phosphofructo-2- kinase/fructose-2,6-biphosphatase 3 (PFKFB3), and pyruvate kinase isozyme type M2 (PKM2) in PAMs (P<0.05 and 0.01, respectively). Glycolysis inhibitors down-regulated the expression of PRRSV proteins and reduced virus titers (P<0.01). The knockdown of HIF-1α by siRNAs inhibited glycolysis and lowered PRRSV titers (P<0.05). In addition, the interferon pathways inhibited by PRRSV infection were reversed by the inhibition of glycolysis. These findings may facilitate further investigation of the role of glycolysis in PRRSV replication.

Abstract:This study aimed to explore the roles of microRNAs (miRNAs) in the post-transcriptional regulation of cocaine- and amphetamine-regulated transcript (CART) peptide in the bovine hypothalamus and to screen key regulatory miRNAs. Targetscan was used to predict the potential miRNAs binding to CART 3ʹ untranslated regions (3ʹUTR). Bioinformatics analysis predicted 7 miRNA binding sites in the bovine CART 3ʹUTR, which were bta-miR-377, bta-miR-331-3p, bta-miR-491, bta-miR-493, bta-miR-758, bta-miR-877, and bta-miR-381, respectively. Reverse transcription-PCR (RT-PCR) was carried out to determine the endogenous expression of CART and target miRNAs in the bovine hypothalamus. All the 7 target miRNAs and CART were endogenously expressed in the bovine hypothalamus. The dual-luciferase reporter gene assay was employed to detect the targeted binding relationship between CART 3ʹUTR and target miRNAs obtained from bioinformatics analysis. The dual-luciferase reporter gene assay confirmed that the 3ʹUTR of CART had a targeted binding relationship with the 7 target miRNAs. Cell experiments were conducted to examine the effects of target miRNAs on the messenger RNA (mRNA) and protein levels of exogenous CART and screen for key regulatory miRNAs. The results of cell experiments showed that the 7 miRNAs downregulated the mRNA level of CART, with bta-miR-491 demonstrating the strongest downregulating effect. Bta-miR-377, bta-miR-331-3p, bta-miR-491, bta-miR-493, and bta-miR-381 downregulated the protein level of CART, with bta-miR-381 exerting the strongest downregulating effect. Animal experiments were conducted to explore the effects of key regulatory miRNAs on the mRNA and protein levels of CART in the hypothalamus and the CART concentration in the serum. The results from animal experiments showed that miR-491 and miR-381 regulated the endogenous expression of CART in the hypothalamus and the concentration in the serum by binding to the CART 3ʹUTR. These results suggest that miR-491 and miR-381 are the main miRNAs regulating CART expression in the bovine hypothalamus, which can affect serum CART concentration by modulating endogenous CART expression.

Abstract:Porcine deltacoronavirus (PDCoV) is a major pathogen causing fatal diarrhea in suckling piglets, and there is currently a lack of effective vaccines and drugs to prevent and control the virus. The nonstructural protein 13 (NSP13) serves as a virus-coded helicase and is considered to be a crucial target for antiviral drugs, making it imperative to investigate the helicase activity of NSP13. In this study, the NSP13 gene of PDCoV was synthesized and integrated into the prokaryotic expression vector pET-28a to construct the recombinant plasmid pET-28a-NSP13. NSP13 was successfully expressed in BL21 (DE3) and subsequently purified. The study also verified the helicase activity of the purified NSP13 and explored the factors that influence this activity. The results indicated that NSP13 from PDCoV was effectively expressed in the prokaryotic system and exhibited helicase activity, capable of unwinding double-stranded DNA with a tail at the 5ʹ end. Additionally, NSP13 demonstrated an annealing function by promoting the complementary pairing of single-stranded nucleotide chains to form double strands. The helicase activity of NSP13 was affected by metal ions, but Mg²⁺concentrations in the range of 0.5–6.0 mmol/L had no significant effect on helicase activity of NSP13. When the solution pH was in the range of 4–9, there was no difference in helicase activity. ATP concentrations in the range of 0.25–6.00 mmol/L had a weak effect on helicase activity, and NSP13 concentration ≥80 nmol/L inhibited the helicase activity. We obtained the NSP13 of PDCoV and investigated its helicase activity. These findings provided a theoretical foundation for the further research on the regulatory mechanism of NSP13 in PDCoV replication and the development of anti-coronaviral drugs.

Abstract:This study aims to optimize the process for preparing chitosan-based ultrasound- coupled hydrogel pads and investigate their application potential in ultrasonography. Chitosan, 2-acrylamido-2-methylpropanesulfonic acid, and N-isopropylacrylamide were used as the main materials to prepare chitosan-based ultrasound-coupled hydrogel pads. The free-radical polymerization conditions were optimized by a three-factor, three-level orthogonal test with the tensile strength and ultrasound image quality of the hydrogel pads as evaluation indicators. The optimal prescription was selected by optimizing three factors of raw material ratio, polymerization temperature, and freeze-drying time. The structure and performance of the hydrogel pads were characterized by a scanning electron microscope, a universal testing machine, and an ultrasonic diagnostic instrument. The results showed that the optimal prescription was as follows: the chitosan:2-acrylamide-2-methylpropanesulfonic acid:N-isopropylacrylamide ratio of 2:0.55:17.27, the polymerization temperature of 25 ℃, and the freeze-drying time of 48 h. The ultrasonically-coupled hydrogel pads prepared under these conditions were transparent, with a porous structure, good adhesion, and high tensile strength. The hydrogel pads had good swelling properties and the swelling degree decreased slowly on day 10. The quality of the ultrasound images obtained via chitosan-based hydrogel pads was not significantly different from that obtained via medical ultrasound coupling agent. In this study, we analyzed the effects of different preparation processes on the gel formation of chitosan-based ultrasound-coupled hydrogel pads. The hydrogel pads were transparent and mild and non-irritating to the human body, serving as an ultrasound transmission material for ultrasonography.

Abstract:The probiotic strain Escherichia coli Nissle 1917 (EcN) with high biocompatibility and susceptibility to genetic modification is often applied in bacterial therapies for cancer. However, most studies have used plasmids as vectors to construct engineering strains from EcN. Plasmid-based expression systems suffer from genetic instability, and they need antibiotic selective pressure to maintain high copy number. This study aimed to employ EcN for synthesizing the photosensitizer 5-aminolevulinic acid (5-ALA). Firstly, the key genes of 5-ALA synthesis, hemA^M and hemL, were integrated into the EcN genome by the phage integration technique. Then, chemically inducible chromosomal evolution (CIChE) was adopted to increase the copy number of hemA^M and hemL and thus improved the stable synthesis of 5-ALA. The in vitro cell experiments verified that the constructed engineering strain can deliver stably synthesized 5-ALA to tumor cells and inhibit their growth. This study provided a basis for applying the engineering strains of EcN in the photodynamic therapy for tumors.

Abstract:The effects of host factors ADP-ribosylation factor 4 (ARF4) and ADP-ribosylation factor 5 (ARF5) upon Zika virus (ZIKV) infection in vivo were characterized by construction of gene knockout mice via CRISPR-Cas9. Firstly, ARF5 and ARF4 genes were modified by the CRISPR-Cas9 system and then microinjected into the fertilized eggs of C57BL/6JGpt mice. Fertilized eggs were transplanted to obtain ARF4 or ARF5 knockout (ARF4KO or ARF5KO) mice, and ARF4/5 double knockout mice were achieved by the mating between ARF4KO and ARF5KO mice (ARF4KO/ARF5KO). Then, the mouse genotypes were identified by PCR to identify the positive knockout mice, and RT-qPCR was employed to examine the knockout efficiency. The mice were then infected with ZIKV and the blood and tissue samples were collected after 2, 4, and 6 days. RT-qPCR was then employed to determine the virus load, and hematoxylin-eosin staining was employed to observe the pathological changes in the tissue. The results showed that expected PCR bands were detected from ARF4KO^–/+, ARF5KO^–/–, and ARF4KO^–/+/ARF5KO^–/– mice, respectively. The results of mRNA transcription measurement indicated the significant knockdown of ARF4 by 37.8%–50.0% but not ARF5 in ARF4KO^–/+ compared with the wild-type mice. Meanwhile, complete knockout of ARF5 and no changes in ARF4 were observed in ARF5KO^–/– mice. Additionally, completed knockout of ARF5 and down-regulated mRNA level of ARF4 in the lung, kidney, and testis were detected in ARF4KO^–/+/ARF5KO^–/–mice in comparison with the wild-type mice. The virus load in the serum decreased in ARF4KO^–/+ mice, while it showed no significant change in ARF5KO^–/– or ARF4KO^–/+/ARF5KO^–/– mice compared with that in the wild type. Meanwhile, ARF4KO^–/+ mice showcased no significant difference in virus load in various tissues but attenuated pathological changes in the brain and testis compared with the wild-type mice. We successfully constructed ARF4KO and ARF5KO mice by CRISPR-Cas9 in this study. ARF4 rather than ARF5 is essential for ZIKV infection in vivo. This study provided animal models for studying the roles of ARF4 and ARF5 in ZIKV infection and developing antivirals.

Abstract:The purpose of this study is to construct a muscle-specific synthetic promoter library, screen out muscle-specific promoters with high activity, analyze the relationship between element composition and activity of highly active promoters, and provide a theoretical basis for artificial synthesis of promoters. In this study, 19 promoter fragments derived from muscle-specific elements, conserved elements, and viral regulatory sequences were selected and randomLy connected to construct a muscle-specific synthetic promoter library. The luciferase plasmids pCMV-Luc and pSPs-Luc were constructed and transfected into the myoblast cell line C2C12. The activities of the synthesized promoters were evaluated by the luciferase activity assay. Two non-muscle-derived cell lines HeLa and 3T3 were used to verify the muscle specificity of the highly active promoters. The sequences of promoters with high activity, good muscle specificity, and correct sequences were analyzed to explore the relationship between the element composition and activity of promoters. We successfully constructed a muscle-specific promoter library and screened out 321 effective synthetic promoter plasmids. Among them, the activity of SP-301 promoter was 5.63 times that of CMV. The 15 promoters with high activity were muscle-specific. In the promoters with high activity and correct sequences, there was a relationship between their element composition and activity. Muscle-specific elements accounted for a high proportion in the promoters, while they had weak correlations with the promoter activity, being tissue-specific determinants. Viral elements accounted for no less than 20% in highly active promoters, which may be the key elements for the promoter activity. The content of conserved elements was proportional to the promoter activity. This study lays a theoretical foundation for the synthesis of tissue-specific efficient promoters and provides a new idea for the construction and application of in-situ gene delivery systems.

Abstract:To clarify the genetic diversity and structure of the nucleus population of F1-generation Litopenaeus vannamei, this study utilized 15 pairs of highly polymorphic microsatellite primers to analyze the simple sequence repeat (SSR) markers and genetic diversity in 15 full-sib families of L. vannamei. A total of 112 alleles (N_a) and 60.453 effective alleles (N_e) were identified among the selected 15 SSR loci, with the average polymorphic information content (PIC) of 0.648. The average N_e, observed heterozygosity (H_o), and expected heterozygosity (H_e) in the 15 F1 families varied from 1.925 to 2.626, 0.425 to 0.783, and 0.403 to 0.572, respectively. The 15 full-sib families were primarily clustered into three categories in the phylogenetic analysis, with the genetic distance between families ranging from 0.252 to 0.574. Additionally, the genetic differentiation coefficient (F_st) among the families varied from 0.112 to 0.278, indicating substantial genetic differentiation. Overall, this study suggested that the genetic diversity of the 15 full-sib families was moderate, providing valuable genetic insights for the subsequent breeding initiatives aimed at enhancing the tolerance of L. vannamei to high levels of soybean meal.

Abstract:In order to establish a stable in vitro culture platform for chicken small intestine three-dimensional (3D) organoids, in this study, crypt cells were collected from the small intestine of 18-day-old embryos of AA broilers. On the basis of the L-WRN conditioned medium, we optimized the culture conditions of chicken small intestinal organoids by adjusting the proportions of nicotinamide, N-acetylcysteine, LY2157299, CHIR99021, Jagged-1, FGF, and other cytokines to select the medium suitable for the long-term stable growth of the organoids. The optimization results showed that the addition of 1.5 µmol/L CHIR99021 significantly improved the organoid formation efficiency and organoid diameter. When 0.5 µmol/L Jagged-1 was added, a small amount of bud-like tissue appeared in organoids. After the addition of 50 ng/mL FGF-2, the rate of organoid germination was significantly increased. The 1.5 µmol/L CHIR99021, 0.5 µmol/L Jagged-1, and 50 ng/mL FGF-2 added in the medium can cooperate with each other to improve the formation and speed up the proliferation and differentiation of organoids, while improving the stemness maintenance of cells. The morphology, cell types, and culture characteristics of chicken small intestinal organoids were studied by HE staining, transmission electron microscopy, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), indirect immunofluorescence, and immunohistochemistry. The results showed that the 3D organoids of the chicken small intestine cultured in vitro were morphologically consistent with the chicken intestinal tissue and contained differentiated epithelial cells. In summary, we successfully established an in vitro culture system for chicken small intestinal organoids, providing a new method for the subsequent research on chicken intestinal physiology, pathology, and host-pathogen interaction mechanism and the development of relevant drugs.

Abstract:Retinoic acid signaling pathway plays a role in regulating vertebrate development, cell differentiation, and homeostasis. As a key enzyme that catalyzes the oxidation of retinal to retinoic acid, aldehyde dehydrogenase 1 family member A2 (Aldh1a2) is involved in cardiac development, while whether it functions in heart diseases remains to be studied. In this study, we infected primary cardiomyocytes with adenovirus overexpressing Aldh1a2 (Ad-Aldh1a2) to explore the effects of Aldh1a2 overexpression on the biological function of cardiomyocytes. The results showed that the infection with Ad-Aldh1a2 realized the overexpression of Aldh1a2 in cardiomyocytes. Compared with the control group infected with Ad-GFP, the cardiomyocytes infected with Ad-Aldh1a2 showcased significantly increased size and up-regulated expression levels of the atrial natriuretic factor gene (ANF), brain natriuretic peptide gene (BNP), and β-myosin heavy chain (β-MHC). In addition, 5-ethynyl-2ʹ-deoxyuridine (EdU) incorporation assay demonstrated that Aldh1a2 overexpression increased the proportion of cardiomyocytes with positive EdU signals and upregulated the expression levels of proliferation-related genes cyclin D2 (Ccnd2) and budding uninhibited by benzimidazole 1 (Bub1). The above data indicated that overexpression of Aldh1a2 induced hypertrophic growth and proliferation of cardiomyocytes. This study provides a basis for further understanding the function of Aldh1a2 in heart diseases and developing therapies for heart diseases.

Abstract:The structures and activities of enzymes are influenced by pH of the environment. Understanding and distinguishing the adaptation mechanisms of enzymes to extreme pH values is of great significance for elucidating the molecular mechanisms and promoting the industrial applications of enzymes. In this study, the ESM-2 protein language model was used to encode the secreted microbial proteins with the optimal performance above pH 9 and below pH 5, which yielded 47 725 high-pH protein sequences and 66 079 low-pH protein sequences, respectively. A deep learning model was constructed to identify protein acid-base tolerance based on amino acid sequences. The model showcased significantly higher accuracy than other methods, with the overall accuracy of 94.8%, precision of 91.8%, and a recall rate of 93.4% on the test set. Furthermore, we built a website (https://enzymepred.biodesign.ac.cn), which enabled users to predict the acid-base tolerance by submitting the protein sequences of enzymes. This study has accelerated the application of enzymes in various fields, including biotechnology, pharmaceuticals, and chemicals. It provides a powerful tool for the rapid screening and optimization of industrial enzymes.