Abstract:

Abstract:Some bacteria can selectively colonize the tumor site and inhibit tumor growth, serving as ideal vehicles for delivering antitumor drugs. The system of delivering antitumor drugs with live bacteria as vehicles is characterized by good biocompatibility and precise targeting. However, the development of bacteria as drug delivery vehicles is limited by their own immunogenicity. In this paper, the selection of chassis bacteria, bacterial loading drug strategies, antitumor drug delivery applications and their limitations are elaborated in detail, and its future development direction is envisioned, with a view to providing a reference for the study of live bacteria as antitumor drug delivery carriers.

Abstract:Visual detection is a technique for evaluating the results through visual judgment without relying on complex optical detection systems. It obtains results quickly based on signals, such as visible light, changes in air pressure, and migration distance, that can be directly observed by naked eyes, being widely used in the in vitro diagnostics industry. The CRISPR-Cas system has the potential to be used in the development of point of care testing (POCT) technologies due to the advantages of mild reaction conditions, no need for thermal cycling or other control measures, and a robust signal amplification capability. In recent years, the combination of visual detection and CRISPR-Cas has significantly reduced the need for laboratory infrastructures, precision instruments, and specialized personnel for nucleic acid detection. This has promoted the development of POCT technology and methods for nucleic acids. This article summarizes the signal output modes and characteristics of the visual detection of nucleic acid by CRISPR-Cas and discusses the issues in the application. Finally, its future clinical translation is envisioned with a view to informing the development of CRISPR-Cas visualization assays.

Abstract:Itaconate is a pivotal intermediate metabolite in the tricarboxylic acid (TCA) cycle of immune cells. It is produced by decarboxylation of cis-aconitic acid under the catalysis of aconitate decarboxylase 1 (ACOD1), which is encoded by the immune response gene 1 (IRG1). Itaconate has become a focal point of research on immunometabolism. Studies have demonstrated that itaconate plays a crucial role in diseases by regulating inflammation, remodeling cell metabolism, and participating in epigenetic regulation. This paper reviewed the research progress in itaconnate from its chemical structure, regulatory effects on different diseases, and mechanisms, proposes the future research directions, aiming to provide a theoretical basis for the development of itaconate-related drugs.

Abstract:The small G-protein Rac1 is the main regulatory factor of the actin cytoskeleton. Rac1 cycles between the inactive GDP-bound form and the active GTP-bound form. Rac1 not only promotes viral replication and infection, but also regulates the actin cytoskeleton rearrangement, adhesion, and invasion of glioma cells. In addition, Rac1 is implicated in human diseases such as tumors and epilepsy. This article reviews the latest research on the small G-protein Rac1 in virology, cell biology, and human pathology. It is found that the existence of Rac1 is closely related to the replication and infection of viruses, that is, inhibiting the existence of Rac1 can effectively reduce the replication and transportation of viruses, providing new ideas for the development of various therapeutic drugs targeting Rac1.

Abstract:Proteins with specific functions and characteristics play a crucial role in biomedicine and nanotechnology. De novo protein design enables the customization of sequences to produce proteins with desired structures that do not exist in the nature. In recent years, with the rapid development of artificial intelligence (AI), deep learning-based generative models have increasingly become powerful tools, enabling the design of functional proteins with atomic-level precision. This article provides an overview of the evolution of de novo protein design, with focus on the latest algorithmic models, and then analyzes existing challenges such as low design success rates, insufficient accuracy, and dependence on experimental validation. Furthermore, this article discusses the future trends in protein design, aiming to provide insights for researchers and practitioners in this field.

Abstract:Compared with conventional vaccines, mRNA vaccines have considerable advantages in design, production, and application, especially in dealing with emerging infectious diseases. Particularly, mRNA vaccines were the first to be recommended by the World Health Organization for emergency use during the COVID-19 pandemic. A key to the design of mRNA vaccines is to ensure the stable and sufficient expression of the encoded protein in the recipient. In recent years, advances have been attained in the experimental and computational research in this area. This review focused on the progress and problems in improving the translation efficiency of mRNA vaccines in recent years, aiming to promote related research.

Abstract:Prostate cancer is one of the most common malignant tumors in men and posing a serious threat to men’s health. Detection methods such as prostate-specific antigen (PSA), prostate biopsy, and magnetic resonance imaging are widely used for prostate cancer screening, but they have low specificity, high cost, and significant risks. Therefore, there is an urgent need to develop highly specific, low-cost, easily obtained, stable, and reliable biomarkers, and use them as the basis to establish non-invasive screening and diagnostic methods for prostate cancer. This paper reviewed the recent advances in the use of prostate cancer biomarkers and combined detection methods for prostate cancer diagnosis and prognosis assessment and provides an in-depth analysis and comparison of different biomarkers and combined detection methods, as well as points out the directions and challenges for future research. The paper emphasizes the importance of developing efficient, cost-effective and easy-to-implement biomarkers to increase the early diagnosis rate of prostate cancer, improve patient prognosis, and reduce the waste of healthcare resources. This paper provides an important theoretical basis and technical guidance for early diagnosis, precise treatment and prognostic evaluation of prostate cancer, and has important reference value for promoting clinical research and practice of prostate cancer.

Abstract:Bispecific antibody drugs have enhanced efficacy and safety compared with therapeutic monoclonal antibody drugs, gradually becoming a new generation of effective therapies. With the development of genetic engineering and the maturity of the industry, increasing studies have been carried out on bispecific and multi-specific antibody drugs, and the application indications of these drugs are expanding, which lays a foundation for satisfying the clinical needs and creating clinical values. This paper provides a comprehensive review of the development stages, indications, target combinations, structural formats, and mechanisms of bispecific and multi-specific antibody drugs. It also discusses key points and strategies for differentiated drug discovery, facilitating the rapid development of innovative therapies, providing theoretical support for the clinical translation of these drugs, and offering more precise and effective treatment options for clinical practice.

Abstract:Foodborne pathogens are one of the major factors leading to food safety issues, causing harm to the national economy and people’s livelihood. Achieving rapid detection of foodborne pathogens is currently a key strategy for preventing and controlling foodborne diseases. Antibodies naturally possess high specificity and sensitivity, serving as preferred tools for specific recognition of foodborne pathogens. We list the main methods for detecting foodborne pathogens, introduce the evolution and development of polyclonal antibodies, monoclonal antibodies, and genetically engineered antibodies, and review the application of different antibody technologies in the rapid detection of foodborne pathogens. Furthermore, we recognize that the combination of antibody technology and other foodborne pathogen detection methods is currently a reliable means to improve detection performance. Finally, we elaborate on the existing limitations of different antibodies and summarize the current research status and potential issues, aiming to provide a theoretical basis and practical ideas for the development of rapid detection of foodborne pathogens.

Abstract:With the advancement of synthetic biology, recombinant proteins are poised to play a significant role in medical applications. The scaled manufacturing is a pillar for the extensive application and development of recombinant proteins across various fields. In the large-scale production process of recombinant proteins, the removal and detection of endotoxins are essential to reduce their levels to safe thresholds in the final products. Currently, establishing stringent endotoxin limits for different recombinant protein products is a crucial aspect of safety assessment. This review begins by shedding light on the pathogenicity of endotoxins and discusses the methods for the removal and determination of endotoxins during the production processes of recombinant proteins. Subsequently, this review summarizes the endotoxin limits in industries such as biologics, medical devices, and human recombinant DNA products, particularly those in recombinant protein injection products. It is highlighted that regardless of whether the hosts for recombinant protein expression are bacteria or not, endotoxin testing is required for the final products of injectable recombinant proteins, and compliance with relevant industry standards is necessary. This review aims to provide a reference for the research on endotoxins in the large-scale production process of recombinant proteins.

Abstract:Conventional administration methods have problems including low bioavailability, complex operation process, and discomfort of patients with fear of needles. Transdermal delivery can avoid these problems, whereas most drugs are difficult to directly penetrate the skin cuticle and reach the diseased site. Microneedling is an emerging method of local drug delivery, enabling the drug penetration through the stratum corneum of the skin in a minimally invasive manner and delivering the drug directly to the diseased site, thereby improving the treatment effect. Stimuli-responsive microneedles have attracted much attention because of the spatiotemporal controllability, high drug delivery efficiency, and mild potential side effects. This review introduced the commonly used materials and various types of stimuli-responsive microneedles and the drug release mechanisms. In addition, this paper expounded the biomedical applications of stimuli-responsive microneedles as drug delivery systems in response to different stimuli and discusses the challenges and potential solutions for stimuli-responsive microneedles.

Abstract:Vaccination is the most effective measure for reducing and preventing influenza and related complications. In this study, we analyzed the mutation trend and the antigen dominant site changes of the amino acid sequence of hemagglutinin subunit 1 (HA1) of human influenza A virus (IAV) in the northern hemisphere from 2012 to 2022. According to the HA1 sequences of A/Darwin/6/2021 (H3N2) and A/Wisconsin/588/2019 (H1N1) recommended by the World Health Organization in the 2022 influenza season in northern hemisphere, we employed the mosaic algorithm to design three Mosaic-HA1 antigens through stepwise substitution. Mosaic-HA1 was expressed and purified in 293F cells and then mixed with the alum adjuvant at a volume ratio of 1:1. The mixture was used to immunize BALB/c mice, and the immunogenicity was evaluated. Enzyme-linked immunosorbent assay showed that Mosaic-HA1 induced the production of IgG targeting two types of HA1, the specific IgG titers for binding to H3 protein and H1 protein reached 10⁵ and 10³respectively. The challenge test showed that Mosaic-HA1 protected mice from H3N2 or H1N1. This study designs the vaccines by recombination of major antigenic sites in different subtypes of IAV, giving new insights into the development of multivalent subunit vaccines against influenza.

Abstract:Nucleolar complex associated 4 homolog (NOC4L) is a key factor in ribosome biogenesis, and this study aims to investigate its roles in activated T cells from the perspective of translation regulation. Firstly, flow cytometry was employed to determine the expression levels of NOC4L in the CD4⁺ T cells under different conditions in the transgenic reporter mice expressing Noc4l^mCherry. Subsequently, the expression of NOC4L along with cell proliferation was examined under Th1 and Th17 polarization conditions. Finally, in vitro experiments were conducted to identify the proteins interacting with NOC4L during the activation of Th1 and Th17 cells, on the basis of which the potential mechanisms of NOC4L were explored. The results showed that the expression level of NOC4L increased in activated CD4⁺ T cells, and the expression of NOC4L was closely associated with the proliferation and division of activated T cells. The in vitro experiments revealed interactions between NOC4L and proteins involved in ribosome assembly and cell proliferation during T cell activation. These findings lay a foundation for probing into the post-transcriptional regulation in helper T cells and hold profound significance for understanding the activation and regulatory mechanisms of T cells.

Abstract:The spike (S) protein plays a crucial role in the entry of SARS-CoV-2 into host cells. The S protein contains two subunits, S1 and S2. The receptor-binding domain (RBD) of the S1 subunit binds to the receptor angiotensin-converting enzyme 2 (ACE2) to enter the host cells. Therefore, degrading S1 is one of the feasible strategies to inhibit SARS-CoV-2 infection. The purpose of this study is to develop a degradation tool targeting S1. First, we constructed a HEK 293 cell line stably expressing S1 by using a three-plasmid lentivirus system. The overexpression of the mitochondrial E3 ubiquitin protein ligase 1 (MUL1) in this cell line promoted the ubiquitination of S1 and accelerated its proteasomal degradation. Further research showed the polyubiquitination of S1 catalyzed by MUL1 mainly occurred via the addition of K48-linked chains. Moreover, the specific peptide LCB1, which targets and recognizes S1, was combined with MUL1 to create the chimeric E3 ubiquitin ligase LCB1-MUL1. In comparison to MUL1, this chimeric enzyme demonstrated improved catalytic efficiency, resulting in a reduction of S1’s half-life from 12 h to 9 h. In summary, this study elucidated the mechanism by which MUL1 promotes the ubiquitination modification of S1 and facilitates its degradation through the proteasome, and preliminarily validated the effectiveness of targeted degradation of S1 by chimeric enzyme LCB1-MUL1.

Abstract:To preliminarily understand the pathogenic mechanism of Mycoplasma genitalium (Mg) GroEL protein, we used bioinformatics tools to predict the structure and function of Mg GroEL protein and then constructed the recombinant plasmid pET-28a-GroEL. The protein expression was induced by 0.2 mmol/L IPTG, and the expressed protein was purified by Ni-iminodicitic acid (IDA) column affinity. Tohoku Hospital Pediatrics-1 (THP-1) cells were exposed to 2 μg/mL Mg rGroEL. The levels of interleukin (IL)-1β and tumor necrosis factor (TNF)-α in the cell supernatant were measured by ELISA, and that of IL-6 was measured by an automatic chemiluminescence instrument. The activation of the nuclear factor-kappa B (NF-κB) signaling pathway was visualized by immunofluorescence and Western blotting. The results showed that Mg GroEL was a stable hydrophilic protein composed of 543 amino acid residues, with the relative molecular mass of 58.44 kDa, an isoelectric point of 5.68, and a molecular formula of C₂₅₆₈H₄₃₀₀N₇₀₀O₈₂₅S₈. The secondary structure was mainly composed of α-helices and random coils. Mg GroEL contained 12 B-cell dominant epitopes and 10 T-cell dominant epitopes. It exhibited high homology with the GroEL proteins from Mycoplasma pneumoniae, M. agalactiae, M. arthritidis, M. hyopneumoniae, and M. bovis. Mg rGroEL activated the NF-κB signaling pathway and promoted the secretion of IL-1β, IL-6, and TNF-α in THP-1 cells. These results suggest that Mg GroEL exhibits substantial antigenicity and possesses the capability of triggering inflammation in host cells. This study establishes a theoretical basis for future investigations pertaining to the role and pathogenic mechanisms of Mg GroEL.

Abstract:Protein phosphorylation plays a key role in Mycobacterium tuberculosis, the pathogen of tuberculosis, holding promise as a new target of anti-tuberculosis drugs. We used M. smegmatis, a close relative of M. tuberculosis, as a model organism to study the protein phosphorylation at different growth phases. We identified 573 phosphorylated peptides and 816 phosphorylated sites of 385 proteins in the M. smegmatis samples at both logarithmic and stationary phases, and then established a comprehensive dataset of phosphorylated proteins in M. smegmatis. By comparing the expression levels of phosphorylated proteins between the logarithmic and the stationary phase with the selected ion monitoring (SIM) strategy, we verified 68 upregulated proteins involved in cell division and protein translation, and 69 downregulated proteins mainly involved in the tricarboxylic acid cycle pathway. The differentially expressed phosphorylated proteins were significantly enriched in important cellular cycle events such as cell elongation and division. The findings of this study provide proteome evidence for elucidating the phosphorylation in both M. smegmatis and M. tuberculosis.

Abstract:Urate oxidase (Uox) plays a pivotal role in uric acid (UA) degradation, and it has been applied in controlling serum UA level in clinical treatment of hyperuricemia (HUA). However, because Uox is a heterogenous protein to the human body, the immune rejections typically occur after intravenous administration, which greatly hampers the application of Uox-based agents. In this study, we used Lactococcus lactis NZ9000, a food-grade bacterium, as a host to express exogenous Uox genes, to generate the Uox-expressing engineered strains to treat HUA. Aspergillus flavus-derived Uox (aUox) and the “resurrected” human-derived Uox (hUox) were cloned into vector and expressed in NZ9000, to generate engineered strains, respectively. The engineered NZ9000 strains were confirmed to express Uox and showed UA-lowering activity in a time-dependent manner in vitro. Next, in an HUA mice model established by oral gavage of yeast paste, the UA levels were increased by 85.4% and 106.2% at day 7 and day 14. By contrast, in mice fed with NZ9000-aUox, the UA levels were increased by 39.5% and 48.3% while in mice fed with NZ9000-hUox were increased by 57.0% and 82.9%, suggesting a UA-lowering activity of both engineered strains. Furthermore, compared with allopurinol, the first-line agent for HUA treatment, mice fed with NZ9000-aUox exhibited comparable liver safety but better kidney safety than allopurinol, indicating that the use of engineered NZ9000 strains not only alleviated kidney injury caused by HUA, but could also avoided the risk of kidney injury elicited by using allopurinol. Collectively, our study offers an effective and safe therapeutic approach for HUA long-term treatment and controlling.

Abstract:By targeting the key gene csgD involved in the biofilm formation of Escherichia coli, we employed molecular docking and molecular dynamics simulation to screen the active components of Chinese medicine with inhibitory effects on the biofilm formation from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). After the anti-biofilm properties of the active components were validated in vitro, data-independent acquisition (DIA) proteomics was employed to further identify the differential proteins involved in interfering with the biofilm formation of Escherichia coli. The mechanisms of inhibition were explored with consideration to the phenotype. Through virtual screening, we identified four candidate active components, including tannic acid, narirutin, salvianolic acid B, and rosmarinic acid. Among them, tannic acid demonstrated significant inhibitory effect on the biofilm formation of E. coli. The analysis of differential proteins, combined with relevant phenotype validation, suggested that tannic acid primarily affected E. coli by intervening in pilus assembly, succinic acid metabolism, and the quorum sensing system. This study provided a lead compound for the development of new drugs against biofilm-associated infections in the future.

Abstract:To investigate the mechanism of the major capsid protein VP5 (encoded by the UL19 gene) of oncolytic herpes simplex virus type II (oHSV2) in regulating the antitumor function of immune cells, we constructed a mouse breast cancer cell line 4T1-iRFP-VP5-GFP stably expressing VP5 protein, near-infrared fluorescent protein (iRFP), and green fluorescent protein (GFP) by using the PiggyBac transposon system. Flow cytometry and Western blotting were employed to screen the monoclonal cell lines expressing both GFP and VP5 and examine the expression stability of UL19 in the constructed cell line. The results of SYBR Green I real-time PCR and Western blotting showed that the copies of UL19 and the expression level of VP5 protein in the 15th passage of 4T1-iRFP-VP5-GFP cells were significantly higher than those in the 4T1 cells transiently transfected with UL19, demonstrating the stable insertion of UL19 into the 4T1 cell genome. The real-time cell analysis (RTCA) was employed to monitor the proliferation of 4T1-iRFP-VP5-GFP cells, which showed similar proliferation activity to their parental 4T1 cells. Further studies confirmed that NK92 cells exhibited stronger cytotoxicity against 4T1-iRFP-VP5-GFP cells than against 4T1 cells. This study layed a foundation for elucidating the role of VP5 protein in regulating immune cells, including T cells and NK cells, via HLA-E in 4T1 cells to exert the anti-tumor function.

Abstract:Sepsis is a leading life-threatening problem in intensive care medicine. The recent studies have given insights into the transition from inflammation to long-term immunosuppression in sepsis. This condition might cause physiological changes that comprise the lipopolysaccharide (LPS) tolerance. Most studies about the LPS tolerance focus on the reduced ability of macrophages to secrete pro-inflammatory cytokines. Although this method has identified various molecular changes, it remains ambiguous since changes in the whole cell population are measured as an average and markers are required for cell recognition. A fast and label-free method is in demand to detect cell tolerance and screen therapeutic agents that might reverse the process. In this study, direct current insulator-based dielectrophoresis (DC-iDEP) was used to characterize the biophysical properties (EKMr) of inflamed cells, LPS-tolerant cells, and cells treated with therapeutic agents. The results showed that the EKMr of these cells was 4.28×10⁸, 3.13×10⁸, and 4.25×10⁸ V/m², respectively, suggesting that the established method was useful in distinguishing LPS-tolerant cells. The device holds the promise to be applied in medical diagnosis and medicine screening.

Abstract:Peptide-based hydrogel, the polymer materials with a special network structure, are widely used in various fields of biomedicine due to their stable properties and biocompatibility. Environment-responsive self-assembled peptide aqueous solutions can respond to environment changes by the self-assembly of peptides into nanofiber networks. Peptide-based hydrogels well simulate the extracellular matrix and cell growth microenvironment, being suitable for 3D cell culture and organoid culture. To establish a tumor organoid culture system with peptide-based hydrogels, we cultured Panc-1, U87, and H358 cells in a 3D spherical manner using CulX Ⅱ peptide-based hydrogels in 24-well plates for 15 days. The organoids showed a 3D spherical shape, and their sizes increased with the extension of the culture time, with a final diameter ranging from 150 to 300 μm. The organoids had a large number, varying sizes, good cell viability, clear edges, and a good shape, which indicated successful organoid construction. The tumor organoid culture system established in this study with CulX Ⅱ peptide-based hydrogels provides a model for studying tumor pathogenesis, drug development, and tumor suppression.

Abstract:The transcription factors (TFs) in the NAC family are involved in regulating multiple biological processes, playing an important role in plant growth, development, and stress adaptation. Our previous studies have demonstrated that TaNAC14, a member of the NAC family in wheat (Triticum aestivum L.), positively regulates root growth and development and enhances the drought tolerance of wheat seedlings. In this study, we analyzed the physicochemical properties and structure and verified the subcellular localization and transcriptional activation activity of TaNAC14. The prokaryotic expression vector pET21a-HMT-TaNAC14 was constructed and transformed into Escherichia coli BL21 CodonPlus (DE3)-RIPL. The conditions for inducing the expression of the recombinant protein HMT-TaNAC14 were optimized. The solubility of the recombinant protein was analyzed, and the protein was purified by affinity chromatography on a Ni-nitrilotriacetic acid column. The results indicated that TaNAC14 had a conserved domain of the NAM family. It was located in the nucleus and had transcriptional activation activity. The optimal conditions for expression of the recombinant protein in E. coli were induction with 0.2mmol/L IPTG for 4 h. The recombinant protein mainly existed in the soluble form, and the target protein was obtained after purification. This study lays a foundation for the identification of target genes regulated by TaNAC14.

Abstract:The dehydration responsive element binding (DREB) transcription factors play an important role in plant growth and development and are extensively involved in plant responses to abiotic stress. The DREB family contains six subfamilies, and TINY belongs to the DREB-A4 subfamily. The Arabidopsis thaliana TINY gene, AtTINY, plays a role in regulating plant growth and responses to stress. In order to investigate the evolutionary characterization of the DREB-A4 subfamily and the biological function of the MdTINY gene in apple (Malus domestica), in this study, we used the databases GDDH13 and TAIR and online tools (Expasy and WoLF PSORT) to study the biological information of the DREB-A4 subfamily in apple. In addition, the tertiary structures of the proteins were predicted. The apple DREB-A4 subfamily contained 22 genes, all of which had a conserved AP2 domain, and subcellular localization predictions showed that DREB-A4 subfamily proteins were mainly located in the nucleus. The transgenic calli of MdTINY were obtained by the Agrobacterium-mediated transformation method, and the main biological functions of MdTINY were explored by quantitative real-time PCR (qRT-PCR) combined with anthocyanin content determination. MdTINY shared the highest amino acid sequence similarity with AtTINY. The coding region of MdTINY had a full length of 759 bp, encoding 252 amino acid residues. Analysis of the promoter elements and expression patterns indicated that MdTINY was responsive to light and multiple stress conditions. MdTINY was localized in the nucleus and had transcriptional autoactivation activity. The overexpression of MdTINY in calli inhibited normal growth and promoted anthocyanoside accumulation. These results indicated that MdTINY negatively regulated apple plant growth and promoted fruit coloring, providing a candidate gene for the breeding of apple varieties with high quality of fruit color.

Abstract:Gelsemium elegans, a vine plant of Loganiaceae, has both medicinal and forage values. However, it is susceptible to low temperatures during growth. Exploring low temperature response genes is of great significance for cold resistance breeding of G. elegans. Ethylene response factors (ERFs) are the transcription factors of the AP2/ERF superfamily and play a crucial role in plant stress response. In this study, based on the unigene GeERF involved in the response to low temperature stress in the transcriptome of G. elegans, a full-length cDNA sequence of the transcription factor GeERF4B-1 was cloned from the leaves of G. elegans by reverse transcription-polymerase chain reaction (RT-PCR). Bioinformatics analysis showed that GeERF4B-1 had an open reading frame of 759 bp, encoding a protein composed of 252 amino acid residues and with a relative molecular weight of 27 kDa. The deduced protein was predicted to be an unstable, alkaline, and hydrophilic protein. The phylogenetic tree showed that GeERF4B-1 was in the same clade as the B-4 subfamily of the ERF family. The results of the subcellular localization experiment revealed that GeERF4B-1 was located in the nucleus. Real time quantitative PCR (RT-qPCR) analysis indicated that GeERF4B-1 was expressed in the root, stem, and leaf of G. elegans, with the highest expression level in the root. Compared with the control, the treatments with a low temperature (4 ℃), methyl jasmonate (MeJA), and abscisic acid (ABA) up-regulated the expression level of GeERF4B-1, which reached the peak at 24–48 h. This result revealed that GeERF4B-1 actively responded to low temperature, MeJA, and ABA stresses. However, both sodium chloride (NaCl) and drought treatments down-regulated the expression of GeERF4B-1. In addition, a prokaryotic expression vector of GeERF4B-1 was constructed, and a fusion protein of approximately 52 kDa was yielded after induced expression. The results of the plate stress assay showed that compared with the control, the prokaryotic strain expressing GeERF4B-1 demonstrated enhanced tolerance to low temperatures and sensitivity to salt and mannitol stresses. This study provides theoretical references and potential genetic resources for breeding G. elegans varieties with stress resistance.

Abstract:Human epidermal growth factor (hEGF) can be applied in the treatment of surgical trauma (burns, scalds), tissue repair, skin moisturizing, beauty, skincare, etc. However, the low expression and high cost limit the application of hEGF. In order to improve the expression level of hEGF and reduce the production cost, considering the high expression of polyhedrin, this study fused a partial sequence of polyhedrin with hEGF and expressed the fused sequence by using a silkworm baculovirus expression vector system. In view of the small molecular weight of hEGF, we connected hEGF genes in series and optimized the codons to construct multiple fusion expression vectors by fusing different partial sequences of polyhedrin at the N-terminus. The results showed that through the above strategy, the protein expression level of hEGF was significantly increased. The expression vector containing three concatenated hEGF genes with optimized codons and fused with the sequence encoding 25 or 35 residues at the N-terminus of polyhedrin showed the highest expression level.

Abstract:The variable domain of heavy-chain antibody (VHH) has been developed widely in drug therapy, diagnosis, and research. Escherichia coli is the most popular expression system for VHH production, whereas low bioactivity occurs sometimes. Mammalian cells are one of the most ideal hosts for VHH expression at present. To improve the yield of VHH in Expi293F cells, we optimized the signal peptide (SP) and codons of VHH. Firstly, the fusion protein VHH1-Fc was used to screen SPs. The SP IFN-α2 showed the highest secretion as quantified by enzyme-linked immunosorbent assay (ELISA). Subsequently, codon optimization by improving GC3 and GC content doubled the yield of VHH1 and kept its binding activity to Senecavirus A (SVA). Finally, the mean yields of other 5 VHHs that fused with SP IFN-α2 and codon-optimized were over 191.6 mg/L, and these VHHs had high recovery and high purity in the culture supernatant. This study confirms that SP IFN-α2 and codon optimization could produce VHHs in Expi293F cells efficiently, which provides a reference for the large-scale production of VHHs.

Abstract:Ghrelin, a hormone mainly produced and released by the stomach, has numerous functions, including releasing growth hormones, regulating appetite, and processing sugar and lipids. Researchers have made great efforts to study the relationship between ghrelin and metabolic diseases. It is believed that human butyrylcholinesterase (hBChE) could hydrolyze ghrelin to the inactive form (desacyl-ghrelin). However, the low catalytic activity of wild hBChE against ghrelin hinders the clinical application. Recently, a soluble catalytically active hBChE mutant was successfully expressed in Escherichia coli for the first time. We then adopted HotSpot Wizard 3.0 to analyze the mutant structure and rationally selected 10 mutants. Furthermore, we determined the catalytic activities of the mutants against several substrates and the thermostability of these mutants. The results showed that the mutants E197D and A199S improved catalytic activity against ghrelin by 4.6 times and 3.5 times, respectively. The findings provide clues for treating endocrine diseases with the agents for regulating ghrelin.

Abstract:Metallothionein (MT) plays a significant role in heavy metal removal, antioxidant defense, and immune regulation. The current predominant approach for obtaining natural MT is extraction from tissue, which often entails complex procedures resulting in limited yields. In recent years, researchers have adopted the strategy of fusing labels such as GST or His for the heterologous expression of MT. However, a challenge in industrial production arises from the subsequent removal of these labels, which often leads to a significant reduction in the yield. The fusion with elastin-like polypeptides (ELPs) offers a promising solution for achieving soluble expression of the target protein, while providing a simple and fast purification process. In this study, ELP was fused with MT, which significantly up-regulated the soluble expression of MT. The fusion protein ELP-MT with the purity above 97% was obtained efficiently and simply by inverse transition cycling (ITC). ELP-MT exhibited a remarkable 2,2ʹ-azinobis(3-ethylbenzothiazoline-6- sulfonic acid) ammonium salt (ABTS) scavenging activity, with the half maximal inhibitory concentration (IC₅₀) of 0.77 μmol/L, which was 53.7 times that of the vitamin E derivative Trolox. In addition, the fusion protein demonstrated strong 1,1-diphenyl-2-trinitrohydrazine (DPPH) scavenging ability. Furthermore, ELP-MT had no toxicity to the proliferation and promoted the adhesion and migration of NIH/3T3 cells. All these results indicated that ELP-MT had good biocompatibility. We constructed the fusion protein ELP-MT combining the unique properties of MT and elastin, laying a technical foundation for the large-scale production of recombinant MT and facilitating the applications in food, health supplement, and cosmetic industries.

Abstract:We knocked out the retinoic acid-inducible gene I (RIG-I) in HEK293 cells via CRISPR/Cas9 to reveal the effects of RIG-I knockout on the key factors in the type I interferon signaling pathway. Three single guide RNAs (sgRNAs) targeting RIG-I were designed, and the recombination vectors were constructed on the basis of the pX459 vector and used to transfect HEK293 cells, which were screened by puromycin subsequently. Furthermore, a mimic of virus, poly I:C, was used to transfect the cells screened out. RIG-I knockout was checked by sequencing, real-time quantitative PCR, Western blotting, and immunofluorescence assay. Meanwhile, the expression levels of key factors of type I interferon signaling pathway such as melanoma differentiation-associated gene 5 (MDA5), interferonβ1 (IFNβ1), and nuclear factor-kappa B p65 [NF-κB(p65)], as well as cell viability, were determined. The results showed that two HEK293 cell lines (S1 and S3) with RIG-I knockout were obtained, which exhibited lower mRNA and protein levels of RIG-I than the wild type HEK293 cells (P<0.05). The mRNA levels of MDA5 and IFNβ1 in S1 and S3 cells and the protein level of NF-κB(p65) in S3 cells were lower than those in the wild type (P<0.05). More extranuclear NF-κB(p65) protein was detected in S1 cells than in the wild type after transfection with poly I:C. Plus, the wild-type and S1 cells transfected with poly I:C for 48 h showcased reduced viability (P<0.05), while S3 cells did not display the reduction in cell viability. In summary, the present study obtained two HEK293 cell lines with RIG-I knockout via CRISPR/Cas9, which provided a stable cell model for exploring the mechanism of type I interferon signaling pathway.

Abstract:This study aims to establish a time-resolved fluorescence immunochromatography method for simultaneous determination of human papillomavirus (HPV) type 16 E6 and L1 protein concentrations. The amount of lanthanide microsphere-labeled antibodies, the concentration of coated antibodies, and the reaction time were optimized, and then a test strip for the simultaneous determination of the protein concentrations was prepared. The performance of the detection method was evaluated based on the concordance of the results from clinical practice. The optimal conditions were 8 μg and 10 μg of HPV16 L1 and E6-labeled antibodies, respectively, 1.5 mg/mL coated antibodies, and reaction for 10 min. The detection with the established method for L1 and E6 proteins showed the linear ranges of 5–320 ng/mL and 2–64 ng/mL and the lowest limits of detection of 1.78 ng/mL and 1.09 ng/mL, respectively. There was no cross reaction with human immunodeficiency virus (HIV), treponema pallidum (TP), or HPV18 E6 and L1 proteins. The average recovery rate of the established method was between 97% and 107%. The test strip prepared in this study showed the sensitivity, specificity, and diagnostic accuracy of 97.46%, 90.57%, and 95.32%, respectively, in distinguishing patients with cervical cancer and precancerous lesions from healthy subjects, with the area under the curve (AUC) of 0.980 1 and 95% Confidence Interval (CI) of 0.956 5 to 1.000 0. The time-resolved fluorescence immunochromatography combined with the test strips prepared in this study showed high sensitivity, high accuracy, simple operation, and rapid reaction in the quantitation of HPV16 E6 and L1 proteins. It thus can be used as an auxiliary method for the diagnosis and early screening of cervical cancer and precancerous lesions and the assessment of disease course.

Abstract:The emerging biomedical industry has an increasing demand for the professional talents and puts forward higher requirements for the quality, especially the innovation ability of the talents. Exploring a new model for fostering the innovation ability of postgraduates majoring in biological and medical sciences based on the principle of integrating production, education and research is of practical significance for improving the quality of professional talents and empowering the bio-economic development. Taking the training of innovation ability of postgraduates majoring in biological and medical sciences at Jiangnan University as an example, this paper introduced a new training system of “six integration and six optimizations”. This system included ideological guidance, discipline system, training program, faculty, research innovation platform, and communication and cooperation. Satisfactory cultivation results were achieved with this new system. This paper is expected to provide reference for the training of innovative talents in the biological and medical industry.

Abstract:The Principle of Biotechnology is a compulsory course for undergraduates majoring in bioengineering at Zhejiang University of Technology. In response to the “Double First-Class” initiative and in order to improve the teaching effect of this course and the quality of talent training, we reformed the teaching of Principle of Biotechnology, the core course in bioengineering. Specifically, we reorganized the teaching contents, improved the process management of teaching and learning, and implemented multi-dimensional teaching practice. These measures improved teaching quality and promoted the achievement of training goals, which was of great significance for developing “First-Class” disciplines.