BACKGROUND: Epoxyeicosatrienoic acids (EETs), which are metabolites of arachidonic acid catalyzed by cytochrome P450 epoxygenase, are degraded into inactive dihydroxyeicosatrienoic acids by soluble epoxide hydrolase (sEH). Many studies have revealed that sEH gene deletion exerts protective effects against diabetes. Vascular calcification is a common complication of diabetes, but the potential effects of sEH on diabetic vascular calcification are still unknown. METHODS: The level of aortic calcification in wild-type and Ephx2-/- C57BL/6 diabetic mice induced with streptozotocin was evaluated by measuring the aortic calcium content through alizarin red staining, immunohistochemistry staining, and immunofluorescence staining. Mouse vascular smooth muscle cell lines (MOVAS cells) treated with β-glycerol phosphate (0.01 mol/L) plus advanced glycation end products (50 mg/L) were used to investigate the effects of sEH inhibitors or sEH knockdown and EETs on the calcification of vascular smooth muscle cells, which was detected by Western blotting, alizarin red staining, and Von Kossa staining. RESULTS: sEH gene deletion significantly inhibited diabetic vascular calcification by increasing levels of EETs in the aortas of mice. EETs (especially 11,12-EET and 14,15-EET) efficiently prevented the osteogenic transdifferentiation of MOVAS cells by decreasing nidogen-2 (NID2) expression. Interestingly, suppressing sEH activity by small interfering ribonucleic acid or specific inhibitors did not block osteogenic transdifferentiation of MOVAS cells induced by β-glycerol phosphate and advanced glycation end products. NID2 overexpression significantly abolished the inhibitory effect of sEH gene deletion on diabetic vascular calcification. Moreover, NID2 overexpression mediated by adeno-associated virus 9 vectors markedly increased insulin-like growth factor 2 (IGF2) and phospho-ERK1/2 expression in MOVAS cells. Overall, sEH gene knockout inhibited diabetic vascular calcification by decreasing aortic NID2 expression and, then, inactivating the downstream IGF2-ERK1/2 signaling pathway. CONCLUSIONS sEH gene deletion markedly inhibited diabetic vascular calcification through repressed osteogenic transdifferentiation of vascular smooth muscle cells mediated by increased aortic EET levels, which was associated with decreased NID2 expression and inactivation of the downstream IGF2-ERK1/2 signaling pathway.
Animals ; Mice ; Vascular Calcification/metabolism* ; Mice, Inbred C57BL ; Epoxide Hydrolases/metabolism* ; Diabetes Mellitus, Experimental/genetics* ; Male ; Gene Deletion ; MAP Kinase Signaling System/genetics* ; Cell Line ; Immunohistochemistry ; Muscle, Smooth, Vascular/metabolism* ; Signal Transduction/genetics* ; Mice, Knockout

Objective To investigate the expression of blood basophil activation markers in patients with allergic rhinitis (AR) and the effects of allergens on their expression. Methods The blood samples were collected from the following four groups: healthy control (HC), AR patients with negative skin prick test (nAR), seasonal AR patients (sAR) and perennial AR patients (pAR). Flow cytometry was employed to analyze the expression of basophil activation markers Immunoglobulin E receptor I alpha(FcepsilonRIα), CD63 and CD203c in AR patients. Plasma levels of interleukin 4 (IL-4) and IL-8 were measured by liquid-phase chip technology, and their correlations with the percentages of activated basophils were further analyzed. An ovalbumin-induced AR mouse model was established, and the expression levels of FcepsilonRIα and CD63 on blood basophils were detected. Results The expression of FcepsilonRIα, CD203c and CD63 on basophils were increased in nAR, sAR and pAR patients. Allergens enhanced the mean florescence intensity expression of CD63 and CD203c on basophils of sAR and pAR patients. The plasma levels of IL-4 and IL-8 were elevated in nAR, sAR and pAR patients, showing moderate to high correlations with the expression levels of basophil activation markers. The FcepsilonRIαand CD63 expression on basophils of AR mice were increased. Conclusion Allergens may contribute to AR pathogenesis by upregulating the expression of FcepsilonRIα, CD63 and CD203c, as well as promoting the secretion of IL-4 and IL-8.
Basophils/metabolism* ; Humans ; Allergens/immunology* ; Animals ; Rhinitis, Allergic/blood* ; Female ; Male ; Adult ; Mice ; Biomarkers/blood* ; Tetraspanin 30/blood* ; Interleukin-4/blood* ; Interleukin-8/blood* ; Receptors, IgE/blood* ; Phosphoric Diester Hydrolases ; Young Adult ; Pyrophosphatases ; Middle Aged ; Mice, Inbred BALB C

Soybean meal (SBM) prepared by soybean crushing is the most popular protein source in the poultry and livestock industries (Cai et al., 2015) due to its economic manufacture, high protein content, and good nutritional value. Despite these benefits, SBM contains various antigen proteins such as glycinin and β-conglycinin, which account for approximately 70% of the total proteins of the SBM and reduce digestibility and damage intestinal function (Peng et al., 2018). Treating SBM with proteases (neutrase, alcalase, and trypsin) or fermentation can eliminate these antigen proteins (Contesini et al., 2018). Because of its safety and rapid growth cycle, Bacillus strains are considered ideal for the fermentation industry (Yao et al., 2021). SBM fermented by Bacillus yields products with high nutritional value and low levels of antinutritional factors (ANFs), stimulating research in this area (Yuan et al., 2017). Kumari et al. (2023) demonstrated that fermentation with Bacillus species effectively degrades antigen proteins and increases crude protein content. The degradation of antigen proteins relies on protease hydrolysis. Low protease production is the major obstacle hindering the widespread use of microbial fermentation techniques.
Bacillus amyloliquefaciens/metabolism* ; Fermentation ; Glycine max/metabolism* ; Soybean Proteins/metabolism* ; Peptide Hydrolases/metabolism* ; Ribosomes/metabolism* ; Globulins ; Antigens, Plant ; Seed Storage Proteins

To screen and identify a chitosanase with high stability, we cloned the chitosanase gene from Bacillus atrophaeus with a high protease yield from the barren saline-alkali soil and expressed this gene in Escherichia coli. The expressed chitosanase of B. atrophaeus (BA-CSN) was purified by nickel-affinity column chromatography. The properties including optimal temperature, optimal pH, substrate specificity, and kinetic parameters of BA-CSN were characterized. The results showed that BA-CSN had the molecular weight of 31.13 kDa, the optimal temperature of 55 ℃, the optimal pH 5.5, and good stability at temperatures below 45 ℃ and pH 4.0-9.0. BA-CSN also had good stability within 4 h of pH 3.0 and 10.0, be activated by K⁺, Na⁺, Mn²⁺, Ca²⁺, Mg²⁺, and Co²⁺, (especially by Mn²⁺), and be inhibited by Fe³⁺, Cu²⁺, and Ag⁺. BA-CSN showcased the highest relative activity in the hydrolysis of colloidal chitosan, and it had good hydrolysis ability for colloidal chitin. Under the optimal catalytic conditions, BA-CSN demonstrated the Michaelis constant K_m and maximum reaction rate V_max of 9.94 mg/mL and 26.624 μmoL/(mL·min), respectively, for colloidal chitosan. In short, BA-CSN has strong tolerance to acids and alkali, possessing broad industrial application prospects.
Bacillus/genetics* ; Hydrogen-Ion Concentration ; Escherichia coli/metabolism* ; Glycoside Hydrolases/biosynthesis* ; Substrate Specificity ; Enzyme Stability ; Chitosan/metabolism* ; Temperature ; Kinetics ; Cloning, Molecular ; Bacterial Proteins/biosynthesis* ; Recombinant Proteins/genetics*

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.
Antimicrobial Peptides/pharmacology* ; Humans ; Peptide Hydrolases/metabolism* ; Protein Stability ; Antimicrobial Cationic Peptides/chemistry* ; Anti-Infective Agents/chemistry*

The aim of this study was to prepare tandem multimeric proteins of BmSPI38, a silkworm protease inhibitor, with better structural homogeneity, higher activity and stronger antifungal ability by protein engineering. The tandem multimeric proteins of BmSPI38 were prepared by prokaryotic expression technology. The effects of tandem multimerization on the structural homogeneity, inhibitory activity and antifungal ability of BmSPI38 were explored by in-gel activity staining of protease inhibitor, protease inhibition assays and fungal growth inhibition experiments. Activity staining showed that the tandem expression based on the peptide flexible linker greatly improved the structural homogeneity of BmSPI38 protein. Protease inhibition experiments showed that the tandem trimerization and tetramerization based on the linker improved the inhibitory ability of BmSPI38 to microbial proteases. Conidial germination assays showed that His₆-SPI38L-tetramer had stronger inhibition on conidial germination of Beauveria bassiana than that of His₆-SPI38-monomer. Fungal growth inhibition assay showed that the inhibitory ability of BmSPI38 against Saccharomyces cerevisiae and Candida albicans could be enhanced by tandem multimerization. The present study successfully achieved the heterologous active expression of the silkworm protease inhibitor BmSPI38 in Escherichia coli, and confirmed that the structural homogeneity and antifungal ability of BmSPI38 could be enhanced by tandem multimerization. This study provides important theoretical basis and new strategies for cultivating antifungal transgenic silkworm. Moreover, it may promote the exogenous production of BmSPI38 and its application in the medical field.
Animals ; Antifungal Agents/pharmacology* ; Escherichia coli/metabolism* ; Proteins/metabolism* ; Protease Inhibitors/chemistry* ; Bombyx/chemistry* ; Saccharomyces cerevisiae/metabolism* ; Peptide Hydrolases

The purpose of this study was to investigate the effect of aqueous extract of Corni Fructus on β-amyloid protein 25-35(Aβ_(25-35))-induced brain injury and neuroinflammation in Alzheimer's disease(AD) mice to provide an experimental basis for the treatment of AD by aqueous extract of Corni Fructus. Sixty C57BL/6J male mice were randomly divided into a sham group, a model group, a positive control group(huperizine A, 0.2 mg·kg~(-1)), a low-dose aqueous extract of Corni Fructus group(1.3 g·kg~(-1)), a medium-dose aqueous extract of Corni Fructus group(2.6 g·kg~(-1)), and a high-dose aqueous extract of Corni Fructus group(5.2 g·kg~(-1)). The AD model was induced by lateral ventricular injection of Aβ_(25-35) in mice except for those in the sham group, and AD model mice were treated with corresponding drugs by gavage for 24 days. The behavioral test was performed one week before animal dissection. Hematoxylin-eosin(HE) staining was performed to observe the morphology of neurons in the hippocampal region. Flow cytometry was used to detect the apoptosis level of primary hippocampal cells in mice. ELISA kits were used to detect the levels of β-amyloid protein 1-42(Aβ_(1-42)) and phosphorylated microtubule-associated protein Tau(p-Tau) in mouse brain tissues. Immunofluorescence and Western blot were used to detect the expression of related proteins in mouse brain tissues. MTT assay was used to detect the effect of compounds in aqueous extract of Corni Fructus on Aβ_(25-35)-induced N9 cell injury. Molecular docking was employed to analyze the interactions of caffeic acid, trans-p-hydroxy cinnamic acid, isolariciresinol-9'-O-β-D-glucopyranoside, esculetin, and(+)-lyoniresinol with β-amyloid precursor protein(APP), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α). Aqueous extract of Corni Fructus could improve the learning and memory abilities of Aβ_(25-35)-induced mice by increasing the duration of the autonomous activity, the rate of autonomous alternation, the preference coefficient, and the discrimination coefficient, and reduce Aβ_(25-35)-induced brain injury and neuroinflammation in mice by increasing the expression levels of interleukin-10(IL-10) and B-cell lymphoma-2(Bcl-2) in brain tissues, decreasing the expression levels of Aβ_(1-42), p-Tau, IL-6, TNF-α, cysteine aspartate-specific protease 3(caspase-3), cysteine aspartate-specific protease 9(caspase-9), and Bcl-2-associated X protein(Bax), and decreasing the number of activated glial cells in brain tissues. The results of cell experiments showed that esculetin and(+)-lyoniresinol could improve Aβ_(25-35)-induced N9 cell injury. Molecular docking results showed that caffeic acid, trans-p-hydroxy cinnamic acid, isolariciresinol-9'-O-β-D-glucopyranoside, esculetin, and(+)-lyoniresinol had good binding affinity with APP and weak binding affinity with IL-6 and TNF-α. Aqueous extract of Corni Fructus could ameliorate cognitive dysfunction and brain damage in Aβ_(25-35)-induced mice by reducing the number of apoptotic cells and activated glial cells in the brain and decreasing the expression level of inflammatory factors. Caffeic acid, trans-p-hydroxy cinnamic acid, isolariciresinol-9'-O-β-D-glucopyranoside, esculetin, and(+)-lyoniresinol may be the material basis for the anti-AD effect of aqueous extract of Corni Fructus.
Mice ; Male ; Animals ; Alzheimer Disease/drug therapy* ; Amyloid beta-Peptides/metabolism* ; Cornus/metabolism* ; Neuroinflammatory Diseases ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6 ; Aspartic Acid ; Cysteine/therapeutic use* ; Molecular Docking Simulation ; Mice, Inbred C57BL ; Brain Injuries ; Peptide Hydrolases ; Disease Models, Animal ; Mice, Transgenic

OBJECTIVE: To explore the clinical phenotype and genetic features of two children with MEGDEL syndrome due to variants of the SERAC1 gene. METHODS: Two children who had presented at the Fujian Medical University Union Hospital respectively on July 14, 2020 and July 28, 2018 were selected as the study subjects. Clinical features and results of genetic testing were retrospectively analyzed. RESULTS: Both children had featured developmental delay, dystonia and sensorineural deafness, along with increased urine 3-methylglutaric acid levels. Magnetic resonance imaging revealed changes similar to Leigh-like syndrome. Gene sequencing revealed that both children have harbored pathogenic compound heterozygous variants of the SERAC1 gene, including c.1159C>T and c.442C>T in child 1, and c.1168C>T and exons 4~9 deletion in child 2. CONCLUSION Children with MEGDEL syndrome due to SERAC1 gene variants have variable clinical genotypes. Delineation of its clinical characteristics and typical imaging changes can facilitate early diagnosis and treatment. Discovery of the novel variants has also enriched the spectrum of SERAC1 gene variants.
Humans ; Retrospective Studies ; Metabolism, Inborn Errors ; Hearing Loss, Sensorineural/genetics* ; Dystonia ; Carboxylic Ester Hydrolases

Plastics have brought invaluable convenience to human life since it was firstly synthesized in the last century. However, the stable polymer structure of plastics led to the continuous accumulation of plastic wastes, which poses serious threats to the ecological environment and human health. Poly(ethylene terephthalate) (PET) is the most widely produced polyester plastics. Recent researches on PET hydrolases have shown great potential of enzymatic degradation and recycling of plastics. Meanwhile, the biodegradation pathway of PET has become a reference model for the biodegradation of other plastics. This review summarizes the sources of PET hydrolases and their degradation capacity, degradation mechanism of PET by the most representative PET hydrolase-IsPETase, and recently reported highly efficient degrading enzymes through enzyme engineering. The advances of PET hydrolases may facilitate the research on the degradation mechanism of PET and further exploration and engineering of efficient PET degradation enzymes.
Humans ; Hydrolases/metabolism* ; Polyethylene Terephthalates/metabolism* ; Plastics/metabolism* ; Ethylenes

PET (polyethylene terephthalate) is one of the most important petrochemicals that is widely used in mineral water bottles, food and beverage packaging and textile industry. Because of its stability under environmental conditions, the massive amount of PET wastes caused serious environmental pollution. The use of enzymes to depolymerize PET wastes and upcycling is one of the important directions for plastics pollution control, among which the key is the depolymerization efficiency of PET by PET hydrolase. BHET (bis(hydroxyethyl) terephthalate) is the main intermediate of PET hydrolysis, its accumulation can hinder the degradation efficiency of PET hydrolase significantly, and the synergistic use of PET hydrolase and BHET hydrolase can improve the PET hydrolysis efficiency. In this study, a dienolactone hydrolase from Hydrogenobacter thermophilus which can degrade BHET (HtBHETase) was identified. After heterologous expression in Escherichia coli and purification, the enzymatic properties of HtBHETase were studied. HtBHETase shows higher catalytic activity towards esters with short carbon chains such as p-nitrophenol acetate. The optimal pH and temperature of the reaction with BHET were 5.0 and 55 ℃, respectively. HtBHETase exhibited excellent thermostability, and retained over 80% residual activity after treatment at 80 ℃ for 1 hour. These results indicate that HtBHETase has potential in biological PET depolymerization, which may facilitate the enzymatic degradation of PET.
Hydrolases/metabolism* ; Bacteria/metabolism* ; Hydrolysis ; Polyethylene Terephthalates/metabolism*