Estudio computacional de las interacciones moleculares entre el timol y los residuos HIS41 y CYS145 presentes en el sitio activo de la proteasa 3CLpro

La proteína proteasa 3CLpro del SARS-CoV-2 es una enzima crucial para la replicación viral, razón por la cual se convierte en un blanco terapéutico de gran importancia. El timol (2-isopropil-5-me-tilfenol), un compuesto natural que se encuentra en el tomillo (Thymus vulgaris), exhibe potencial actividad antiviral contra la proteasa 3CLpro. En este estudio, usando acoplamiento molecular con AutoDockTools-1.5.6, se evaluaron las energías de interacción molecular entre el timol y los residuos de aminoácidos en el sitio activo de la proteína proteasa 3CLpro. Luego, con la teoría cuántica de Átomos en Moléculas (QTAIM) y la de Interacciones no covalentes (NCI) se analizaron los tipos de interacciones moleculares entre los residuos de aminoácidos identificados y el timol. Los cálculos cuánticos se llevaron con el software Orca-5.0.3, utilizando el método DFT con el funcional M06-2X y el conjunto base aug-cc-pVDZ en fase gaseosa. Los resultados de acoplamiento molecular indican que el timol se une a la proteína 3CL con una energía de interacción igual a -3,784 kcal/mol. El análisis QTAIM indica la presencia de puntos críticos de enlace entre el timol y los residuos HIS41 y CYS145. Además, se observa la formación de un enlace de hidrógeno entre el grupo OH del timol y el residuo CYS145, lo cual es corroborado por los análisis ELF (Electron Localization Function) y NCI (Non Covalent Interactions). Finalmente, el método NCI confirma la presencia de interacciones de Van der Waals con el residuo HIS41. Los resultados sugieren que el mecanismo de inhibición de la actividad de la proteína 3CLpro es controlado por interacciones moleculares tipo puente de hidrógeno e interacciones débiles.

The protease 3CLpro of the SARS-CoV-2 is a crucial enzyme for viral replication, becoming a highly important therapeutic target. Thymol (2-isopropyl-5-methyl-phenol), a naturally occurring compound found in thyme, exhibits potential antiviral activity against the 3CLpro protease. In this study, using molecular docking with AutoDockTools-1.5.6, the molecular interaction energies between thymol and amino acid residues in the active site of the protein protease 3CLpro were evaluated. Then, with the Atoms in Molecules (QTAIM) and Non-covalent Interactions (NCI) theories, the types of molecular interactions between identified amino acid residues and thymol were analyzed. Quantum calculations were carried out with the Orca-5.0.3 software using the DFT method with the M06-2X functional and the aug-cc-pVDZ basis set in the gas phase. The molecular docking results indicate that thymol is linked to the 3CL protein with an interaction energy equal to -3.784 kcal/mol. QTAIM analysis indicates the presence of critical binding sites between thymol and residues HIS41 and CYS145. In addition, the formation of a hydrogen bond between the OH group of thymol and the CYS145 residue is observed, which is corroborated by the ELF and NCI analyses. Finally, the NCI method confirms the presence of Van der Waals interactions with the HIS41 residue. The results suggest that the mechanism of inhibition of the activity of the 3CLpro protein is controlled by molecular interactions such as hydrogen bonding and weak interactions.

A protease 3CLpro do SARS-CoV-2 é uma enzima crucial para a replicação viral, tornando-se um alvo terapêutico de grande importÅncia. O timol (2-isopropil-5-me-tilfenol), um composto natural encontrado no tomilho, exibe potencial atividade antiviral contra a protease 3CLpro. Neste estudo, utilizando o docking molecular com o AutoDockTools-1.5.6, foram avaliadas as energias de interação molecular entre o timol e os residuos de aminoácidos no sítio ativo da proteína protease 3CLpro. Em seguida, com a teoria quantica de atomos em moleculas (QTAIM) e da interacões no-covalentes (NCI), foram analisados os tipos de interações moleculares entre os resíduos de aminoácidos identificados e o timol. Os cálculos quÅnticos foram realizados com o software Orca-5.0.3 usando o método DFT com o funcional M06-2X e a base aug-cc-pVDZ definida na fase gasosa. Os resultados do docking molecular indicam que o ti-mol está ligado à proteína 3CL com uma energia de interação igual a -3.784 kcal/ mol. A análise QTAIM indica a presença de sítios de ligação críticos entre o timol e os resíduos HIS41 e CYS145. Além disso, observa-se a formação de uma ponte de hidrogênio entre o grupo OH do timol e o resíduo CYS145, o que é corroborado pelas análises ELF e NCI. Finalmente, o método NCI confirma a presença das interações de Van der Waals com o resíduo HIS41. Os resultados sugerem que o mecanismo de inibição da atividade da proteína 3CLpro é controlado por interações moleculares como ligações de hidrogênio e interações fracas.

Study on the role and mechanism of osteogenesis induced by advanced platelet-rich fibrin and β-tricalcium phosphate complex / 口腔疾病防治

Objective @#To investigate the role and mechanism of bone formation caused by the ratio of advanced platelet-rich fibrin (A-PRF) and β-tricalcium phosphate (β-TCP) in rabbit femur defect model, which provides a new idea for clinical treatment of bone defect.@*Methods @#Twenty-four New Zealand white rabbits were divided into model group, 1∶1 complex group (A-PRF∶β-TCP=1∶1), 2∶1 complex group (A-PRF∶β- TCP=2∶1) and 4∶1 complex group (A-PRF∶β- TCP=4∶1）, with 6 rabbits in each group. Femoral defect models were constructed in each group. In the composite group, the bone defect was filled with composite material, while in the model group, no material was filled. After 8 weeks, the animals were euthanized and specimens were collected. Bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.SP) and trabecular number (Tb.N) in femoral defect tissue were measured by micro-CT and photographed. Hematoxylin - eosin staining was used to detect the pathological changes of new bone tissue. The morphological changes of the new bone tissue were observed by scanning electron microscopy. Determination of phospho-mitogen activated protein kinase p38 (p-p38MAPK), CCAAT/enhancer binding protein homologous protein (CHOP) and phospho-cysteine aspartic protease-3 (p-Caspase3) in newborn femur by ELISA. The mRNA expressions of osteoprotegerin (OPG), bone morphogenetic protein-2 (BMP-2), receptor activator of nuclear factor kappa-B ligand (RANKL) and p38MAPK were detected by real-time quantitative PCR. The expression of OPG, BMP-2, RANKL, p-p38MAPK and p-Caspase3 protein in the new bone tissue was observed by immunohistochemistry. @*Results @#In the model group, bone formation in the femoral defect area was slow and osteogenic quality was poor. Compared with the model group, the bone formation and neocapillaries of femoral defect area in the complex group was good, BMD, BV.TV, Tb.Th, Tb.N were increased, and Tb.Sp were decreased, the expressions of p-p38MAPK, CHOP and p-Caspase3 were decreased, and the mRNA and protein expressions of OPG and BMP-2 were increased. The mRNA expression of RANKL and p38MAPK was decreased. Apoptosis in new bone tissue of each group showed the lowest apoptosis rate in samples of the 2∶1 complex group (P<0.05); A-PRF: β-TCP=2∶1 ratio has the best osteogenic effect. @*Conclusion@#The complex composed of A-PRF and β-TCP can promote the expression of OPG, inhibit the expression of RANKL and phosphorylation of p38MAPK, reduce the apoptosis of new bone tissue cells, and promote osteogenic differentiation.

Babaodan Alleviates APAP-induced Acute Liver Injury in Mice by Inhibiting NLRP3/Caspase-1 Pathway / 中国实验方剂学杂志

ObjectiveTo explore the effect of Babaodan （BBD） on the NOD-like receptor pyrin domain containing 3/cysteine aspartate-specific protease-3 （NLRP3/Caspase-1） pathway proteins in mice with acetaminophen （APAP）-induced acute liver injury. MethodC57BL/6 mice were randomly grouped， and BBD （75， 150， 300 mg·kg-1， ig） was administered twice a day for three days. After 2 hours of the last administration， the mice were treated with APAP （400 mg·kg-1， ip）， and the eyeballs were removed to collect blood after 14 hours. Then they were sacrificed by cervical dislocation for sample collection. Hematoxylin-eosin （HE） staining was used to observe the morphological changes of liver tissue cells， and biochemical methods were used to detect the activities of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， superoxide dismutase （SOD）， malondialdehyde （MDA） and myeloperoxidase （MPO） in serum of mice in each group. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was performed to determine the mRNA expression of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β） and IL-6， and Western blot was performed to determine the protein expression of cyclooxygenase-2 （COX-2）， inducible nitric oxide synthase （iNOS）， NLRP3， Caspase-1 and IL-18 in the liver of mice. ResultCompared with the conditions in normal group， the hepatic lobule structure of mice in the model group was partially destroyed， and the hepatic sinusoids were dilated. And the expression levels of ALT and AST in serum， the protein levels of NLRP3， Caspase-1， iNOS， IL-18 and COX-2 and the mRNA levels of IL-1β， IL-6 and TNF-α were increased （P<0.05， P<0.01）. Compared with the model group， the administration groups had improvement in liver cell rupture and hepatic sinusoidal compression， and a dose-dependent decrease in the levels of ALT and AST in serum as well as the protein levels of NLRP3， Caspase-1， iNOS， IL-18 and COX-2 and the the mRNA levels of IL-1β， IL-6 and TNF-α in liver tissue （P<0.05， P<0.01）. ConclusionBBD can reduce APAP-induced acute liver injury in mice. The mechanism may be related to anti-oxidative stress， inhibition of NLRP3/Caspase-1 pathway， and decreased expression levels of IL-1β， IL-18， TNF-α and IL-6.

UHRF1/DNMT1-MZF1 axis-modulated intragenic site-specific CpGI methylation confers divergent expression and opposing functions of PRSS3 isoforms in lung cancer

As confusion mounts over RNA isoforms involved in phenotypic plasticity, aberrant CpG methylation-mediated disruption of alternative splicing is increasingly recognized as a driver of intratumor heterogeneity (ITH). Protease serine 3 (PRSS3), possessing four splice variants (PRSS3-SVs; PRSS3-V1-V4), is an indispensable trypsin that shows paradoxical effects on cancer development. Here, we found that PRSS3 transcripts and their isoforms were divergently expressed in lung cancer, exhibiting opposing functions and clinical outcomes, namely, oncogenic PRSS3-V1 and PRSS3-V2 versus tumor-suppressive PRSS3-V3, by targeting different downstream genes. We identified an intragenic CpG island (iCpGI) in PRSS3. Hypermethylation of iCpGI was mediated by UHRF1/DNMT1 complex interference with the binding of myeloid zinc finger 1 (MZF1) to regulate PRSS3 transcription. The garlic-derived compound diallyl trisulfide cooperated with 5-aza-2'-deoxycytidine to exert antitumor effects in lung adenocarcinoma cells through site-specific iCpGI demethylation specifically allowing MZF1 to upregulate PRSS3-V3 expression. Epigenetic silencing of PRSS3-V3 via iCpGI methylation (iCpGIm) in BALF and tumor tissues was associated with early clinical progression in patients with lung cancer but not in those with squamous cell carcinoma or inflammatory disease. Thus, UHRF1/DNMT1-MZF1 axis-modulated site-specific iCpGIm regulates divergent expression of PRSS3-SVs, conferring nongenetic functional ITH, with implications for early detection of lung cancer and targeted therapies.

Hypoxia-induced ROS aggravate tumor progression through HIF-1α-SERPINE1 signaling in glioblastoma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Hypoxia, as an important hallmark of the tumor microenvironment, is a major cause of oxidative stress and plays a central role in various malignant tumors, including glioblastoma. Elevated reactive oxygen species (ROS) in a hypoxic microenvironment promote glioblastoma progression; however, the underlying mechanism has not been clarified. Herein, we found that hypoxia promoted ROS production, and the proliferation, migration, and invasion of glioblastoma cells, while this promotion was restrained by ROS scavengers N-acetyl-L-cysteine (NAC) and diphenyleneiodonium chloride (DPI). Hypoxia-induced ROS activated hypoxia-inducible factor-1α (HIF-1α) signaling, which enhanced cell migration and invasion by epithelial-mesenchymal transition (EMT). Furthermore, the induction of serine protease inhibitor family E member 1 (SERPINE1) was ROS-dependent under hypoxia, and HIF-1α mediated SERPINE1 increase induced by ROS via binding to the SERPINE1 promoter region, thereby facilitating glioblastoma migration and invasion. Taken together, our data revealed that hypoxia-induced ROS reinforce the hypoxic adaptation of glioblastoma by driving the HIF-1α-SERPINE1 signaling pathway, and that targeting ROS may be a promising therapeutic strategy for glioblastoma.

The expression and significance of protease activated receptor 2 in ovarian epithelial carcinoma / 中华肿瘤杂志

Objective: To investigate the expression and significance of protease activated receptor 2 (PAR2) in ovarian epithelial carcinoma. Methods: PAR2 mRNA expression levels in 410 cases of epithelial ovarian carcinoma and 88 cases of human normal ovary were analyzed from cancer Genome Atlas (TCGA) database and tissue genotypic expression database (GTEx). Immunohistochemical (IHC) staining of PAR2 protein was performed in 149 patients with ovarian cancer who underwent primary surgical treatment at Cancer Hospital of Chinese Academy of Medical Sciences. Then the relationship between mRNA/protein expression of PAR2 and clinicopathological features and prognosis was analyzed. Gene functions and related signaling pathways involved in PAR2 were studied by enrichment analysis. Results: The mRNA expression of PAR2 in epithelial ovarian carcinoma was significantly higher than that in normal ovarian tissue (3.05±0.72 vs. 0.33±0.16, P=0.004). There were 77 cases showing positive and 19 showing strong positive of PAR2 IHC staining among the 149 patients, accounting for 64.4% in total. PAR2 mRNA/protein expression was closely correlated with tumor reduction effect and initial therapeutic effect (P<0.05). Survival analysis showed that the progression free survival time (P=0.033) and overall survival time (P=0.011) in the group with high PAR2 mRNA expression was significantly lower than that in the low PAR2 mRNA group. Multivariate analysis showed tumor reduction effect, initial therapeutic effect were independent prognostic factors on both progression-free survival and overall survival (P<0.05). The progression-free survival (P=0.016) and overall survival (P=0.038) of the PAR2 protein high expression group was significantly lower than that of the low group. Multivariate analysis showed PAR2 expression, initial treatment effect and chemotherapy resistance were independent prognostic factors on both progression-free survival and overall survival (P<0.05). Based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), PAR2 target genes were mainly enriched in function related to intercellular connection, accounting for 40%. Gene enrichment analysis (GSEA) showed that the Wnt/β-catenin signaling pathway (P=0.023), the MAPK signaling pathway (P=0.029) and glycolysis related pathway (P=0.018) were enriched in ovarian cancer patients with high PAR2 mRNA expression. Conclusions: PAR2 expression is closely related to tumor reduction effect, initial treatment effect and survival of ovarian cancer patients. PAR2 may be involved in Wnt/β-catenin signaling pathway and intercellular connection promoting ovarian cancer invasion and metastasis.

Effect of phenylmethylsulfonyl fluoride, a protease inhibitor, on enamel surface remineralization

Phenylmethylsulfonyl fluoride (PMSF) is a protease inhibitor widely used in research, but fluoride is released during its action and this knowledge has been neglected in dental research. Aim: to evaluate if fluoride released by salivary protease action on PMSF affects enamel remineralization and fluoride uptake. Methods: Groups of 10 enamel slabs, with caries-like lesions and known surface hardness (SH), were subjected to one of the following treatment groups: Stimulated human saliva (SHS), negative control; SHS containing 1.0 µg F/mL (NaF), positive control; and SHS containing 10, 50 or 100 µM PMSF. The slabs were subjected to a pH-cycling regimen consisting of 22 h/day in each treatment solution and 2 h/day in a demineralizing solution. After 12 days, SH was again measured to calculate the percentage of surface hardness recovery (%SHR), followed by enamel fluoride uptake determination. The time-related fluoride release from 100.0 µM PMSF by SHS action was also determined. Data were analyzed by ANOVA followed by Newman-Keuls test. Results: The release of fluoride from PMSF by SHS was rapid, reaching a maximum value after 10 min. Fluoride released from PMSF was more effective in enhancing %SHR and increasing fluoride uptake in enamel compared with SHS alone (p < 0.05); furthermore, it was equivalent to the positive control (p > 0.05). Conclusion: In conclusion, fluoride released by saliva from PMSF is available to react with enamel and needs to be taken into account in research using this protease inhibitor

Which are the best murine models to study Eosinophilic Chronic Rhinosinusitis? A contemporary review

Abstract Objective: Mechanisms that lead to Eosinophilic Chronic Rhinosinusitis (ECRS) are not fully established in the literature. It is desirable to assess ECRS in a model that embraces most of the related events. This article reviewed the murine models for ECRS and compared them regarding eosinophilic polypoid formation. Methods: The authors reviewed the articles that included the terms "chronic rhinosinusitis" OR "chronic sinusitis" AND "animal model". We analyzed articles in English that evaluated both the number of polyps and the number of eosinophils in the sinus mucosa of mouse models. Results: We identified a total of 15 articles describing different models of ECRS that used BALB/c or C57BL/6 mice, and different triggers/stimulants such as Staphylococcus aureus Enterotoxin B (SEB) + Ovalbumin (OVA); House Dust Mite (HDM) ± Ovalbumin (OVA); and Aspergillus oryzae Protease (AP) + Ovalbumin (OVA). OVA associated with SEB was the commonest protocol to induce ECRS in both BALB/c and C57BL/6 mice, and it produced a robust response of eosinophilic nasal polyps in both. AP + OVA protocol also led to a good ECRS response. The other models were not considered adequate to produce eosinophilic polyps in mice. Conclusion: In conclusion, OVA associated with SEB seems to produce the most robust eosinophilic sinonasal inflammation.

Protease inhibitors as a potential agent against visceral Leishmaniasis: A review to inspire future study

Abstract Leishmaniasis is transmitted by sandfly which carries the intracellular protozoa in their midgut. Among visceral, cutaneous and mucocutaneous leishmaniasis, visceral type that is caused by Leishmania donovani is the most lethal one. Findings of leishmanial structure and species took place in 19th century and was initiated by Donovan. Leishmaniasis is still a major concern of health issues in many endemic countries in Asia, Africa, the Americas, and the Mediterranean region. Worldwide1.5-2 million new cases of cutaneous leishmaniasis and 500,000 cases of visceral leishmaniasis are reported each year. Leishmaniasis is endemic in nearly 90 countries worldwide and close to 12 million new cases of leishmaniasis are reported worldwide annually. Studies on antileishmanial drug development is of major concern as leishmaniasis are the second largest parasitic killer in the world and the available drugs are either toxic or costly. The major surface GP63 protease, also known as Zinc- metalloproteases present on the surface of leishmanial promastigotes, can be targeted for drug development. Protease inhibitors targeting such surface proteases show promising results. Different protease inhibitors have been isolated from marine actinobacteria against many infectious diseases. Metabolites produced by these actinobacteria may have greater importance for the discovery and development of new antileishmanial drugs. Hence, this review discusses the background, current situation, treatment, and protease inhibitors from marine actinobacteria for drug development against GP63 molecules.

Discovery of new Schistosoma mansoni aspartyl protease inhibitors by structure-based virtual screening

BACKGROUND Schistosomiasis is a neglected tropical disease caused by trematodes of the genus Schistosoma, with a limited treatment, mainly based on the use of praziquantel (PZQ). Currently, several aspartic proteases genes have already been identified within the genome of Schistosoma species. At least one enzyme encoded from this gene family (SmAP), named SmCD1, has been validated for the development of schistosomicidal drugs, since it has a key role in haemoglobin digestion by worms. OBJECTIVE In this work, we integrated a structure-based virtual screening campaign, enzymatic assays and adult worms ex vivo experiments aiming to discover the first classes of SmCD1 inhibitors. METHODS Initially, the 3D-structures of SmCD1, SmCD2 and SmCD3 were generated using homology modelling approach. Using these models, we prioritised 50 compounds from 20,000 compounds from ChemBridge database for further testing in adult worm aqueous extract (AWAE) and recombinant SmCD1 using enzymatic assays. FINDINGS Seven compounds were confirmed as hits and among them, two compounds representing new chemical scaffolds, named 5 and 19, had IC50 values against SmCD1 close to 100 μM while presenting binding efficiency indexes comparable to or even higher than pepstatin, a classical tight-binding peptide inhibitor of aspartyl proteases. Upon activity comparison against mammalian enzymes, compound 50 was selective and the most potent against the AWAE aspartic protease activity (IC50 = 77.7 μM). Combination of computational and experimental results indicate that compound 50 is a selective inhibitor of SmCD2. Compounds 5, 19 and 50 tested at low concentrations (10 uM) were neither cytotoxic against WSS-1 cells (48 h) nor could kill adult worms ex-vivo, although compounds 5 and 50 presented a slight decrease on female worms motility on late incubations times (48 or 72 h). MAIN CONCLUSION Overall, the inhibitors identified in this work represent promising hits for further hit-to-lead optimisation.

Progresses and analysis in fibrinolytic drugs induced hemorrhage / 药学学报

At present, most clinical thrombolytic drugs are plasminogen activators, which are highly dependent on the plasminogen level of the patient. Therefore, the efficacy of those drugs is restricted. Unlike the conventional thrombolytic plasminogen activator drugs, fibrinolytic drugs have direct fibrinolytic activity. Thus, fibrinolytic drugs can directly dissolve the thrombus, and its thromlysis efficacy is not restricted by the patients' plasminogen. This is a new type of thrombolytic drug with higher thrombolytic efficiency and safety, and has become one of the research hotspots at present. Although more and more agents that can be used as fibrinolytic drugs have been discovered, only a few of them can successfully be applied in clinical practice. The mainly underlying reason is the risk of bleeding. In this paper, based on the latest research progress of fibrinolytic drugs, the bleeding mechanisms and coping strategies of fibrinolytic drugs were systematically reviewed, five types of bleeding mechanisms of fibrinolytic drugs were summarized, and three types of coping strategies were proposed. We hope our work can provide theoretical basis for the development of safer and more efficient fibrinolytic drugs.

Screening methods of SARS-CoV-2 main protease inhibitors and current applications / 药学学报

COVID-19 epidemic continues to spread around the world till these days, and it is urgent to develop more safe and effective new drugs. Due to the limited P3 biosafety laboratories for directly screening inhibitors of virulent viruses with high infectivity, it is necessary to develop rapid and efficient screening methods for viral proteases and other related targets. The main protease (Mpro), which plays a key role in the replication cycle of SARS-CoV-2, is highly conserved and has no homologous proteases in humans, making it an ideal target for drug development. From two different levels, namely, molecular level and cellular level, this paper summarizes the reported screening methods of SARS-CoV-2 Mpro inhibitors through a variety of representative examples, expecting to provide references for further development of SARS-CoV-2 Mpro inhibitors.

Bioinformatics analysis and prokaryotic expression of Strongyloides stercoralis serine protease inhibitor 1 / 中国血吸虫病防治杂志

Objective To predict the structure and antigenic epitope of the Strongyloides stercoralis serine protease inhibitor 1 (Ss-SRPN-1) protein using bioinformatics tools, and to construct prokaryotic expression plasmids for expression of recombinant Ss-SRPN-1 protein, so as to provide the basis for unraveling the function of the Ss-SRPN-1 protein. Methods The amino acid sequence of the Ss-SRPN-1 protein was downloaded from the NCBI database, and the physicochemical properties, structure and antigenic epitopes of the Ss-SRPN-1 protein were predicted using bioinformatics tools, including ExPASy, SWISS-MODEL and Protean. Primers were designed according to the nucleotide sequences of Ss-SRPN-1, and the Ss-SRPN-1 gene was amplified, cloned and sequenced with genomic DNA extracted from the infective third-stage larvae of S. stercoralis as a template. The Ss-SRPN-1 protein sequence was cloned into the pET28a (+) expression vector and transformed into Escherichia coli BL21 (DE) cells for induction of the recombinant Ss-SRPN-1 protein expression. The recombinant Ss-SRPN-1 protein was then purified and identified using Western blotting and mass spectrometry. Results Bioinformatics analysis showed that the Ss-SRPN-1 protein, which was composed of 372 amino acids and had a molecular formula of C1948H3046N488O575S16, was a stable hydrophilic protein, and the subcellular localization of the protein was predicted to be extracellular. The Ss-SRPN-1 protein was predicted to contain 11 dominant B-cell antigenic epitopes and 20 T-cell antigenic epitopes. The Ss-SRPN-1 gene with a length of 1 119 bp was successfully amplified, and the recombinant plasmid pET28a (+)/Ss-SRPN-1 was constructed and transformed into E. coli BL21(DE) cells. The expressed recombinant Ss-SRPN-1 protein had a molecular weight of approximately 43 kDa, and was characterized as a Ss-SRPN-1 protein. Conclusions The recombinant Ss-SRPN-1 protein has been expressed successfully, and this recombinant protein may be a potential vaccine candidate against strongyloidiasis.

Research advance on ubiquitin-specific protease 14 as novel carcinogenesis biomarker / 环境与职业医学

Hazardous environmental factors as well as occupational factors can lead to elevated incidence of diseases including tumors, and specific molecular biomarkers are needed to guide the diagnosis and treatment of diseases. In recent years, ubiquitin-specific protease 14 (USP14) has gradually attracted the attention of researchers. USP14 is widely expressed in various organs of human body and regulates the stability and degradation of important proteins in various signaling pathways. Studies have shown that its abnormal expression is highly correlated with tumors, neurodegenerative diseases, autophagy, immune response, and viral infections, and is involved in the regulation of various classic signaling pathways. It has been shown to play a key role in the development of various human diseases and can be used as a diagnostic and prognostic molecular biomarker and therapeutic target in the development of tumors. This paper reviewed the current status of research on the structure and regulation of USP14 and its function in physiological and pathological processes, with the aim of providing a reference for research on diseases or injuries caused by environmental and occupational factors.

Research progress of SARS-CoV-2 main protease inhibitors / 药学学报

As a common protease with high similarity among coronavirus species, the main protease (Mpro) of SARS-CoV-2 is responsible for the catalytic hydrolysis of viral precursor proteins into functional proteins, which is essential for coronavirus replication and is one of the ideal targets for the development of broad-spectrum antiviral drugs. This paper reviews the main protease inhibitors of SARS-CoV-2, including their molecular structures, potencies and drug-like profiles, binding modes and structure-activity relationships, etc.

Optimization of expression conditions of dengue virus NS2B-NS3 protease in E.coli and determination of enzyme activity / 中国生物制品学杂志

@#Objective To express dengue virus(DENV)NS2B-NS3 protease in E.coli,optimize the expression conditions and determine the enzyme activity,so as to lay a foundation of screening and discovering of lead compounds targeting DENV.Methods Codon-optimized NS2B-NS3 gene was inserted into pET-28a vector to construct recombinant prokaryotic expression plasmid pET-28a-NS2B-NS3,which was transformed E.coli Rosetta(DE3)competent cells and induced by IPTG to express NS2B-NS3 protease. The optimal expression conditions of NS2B-NS3 protease in E.coli were determined by optimizing induction length,induction temperature and IPTG concentration. NS2B-NS3 protease was isolated and purified by HisTrap~(TM) affinity chromatography column and measured for the protease activity by fluorescence resonance energy transfer(FRET)assay.Results The recombinant prokaryotic expression plasmid pET-28a-NS2B-NS3 was constructed correctly as identified by restriction analysis(NheⅠ/XhoⅠ)and sequencing. The optimal expression conditions of NS2BNS3 protease in E.coli were as follows:induction temperature of 20 ℃,induction length of 10 h and IPTG concentration of0. 2 mmol/L. The purified NS2B-NS3 protease showed a purity of more than 90% with a exhibited a of 20 mg/L,which bound to mouse monoclonal antibody against His-tag specifically and had good hydrolytic activity with a specific activity of 16. 111 U/mg,a K_m of 16. 46 μmol/L and a k_(cat) of 0. 028/s.Conclusion DENV NS2B-NS3 protease with high purity and activity was successfully prepared,which laid an experimental foundation of the establishment of high-throughput screening model for inhibitors targeting NS2B-NS3 protease.

Jiedu Huoxue Prescription Regulates NF-κB/NLRP3/Caspase-1 to Promote Vascular Reendothelialization in Rat Model of Injured Thoracic Aorta / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Jiedu Huoxue prescription in promoting the reendothelialization of injured vessels by regulating the nuclear factor （NF）-κB/NOD-like receptor protein 3 （NLRP3）/cysteine-aspartic acid protease （Caspase）-1-mediated pyroptosis. MethodA rat model of injured thoracic aorta was established by balloon injury， and 36 rats were assigned into shame surgery， model， low-， medium-， and high-dose Jiedu Huoxue prescription， and atorvastatin calcium tablet groups. The injured aortic segment was collected 28 days after surgery. Hematoxylin-eosin （HE） staining and Evans blue staining were conducted to reveal the changes of vascular structural morphology and the reendothelialization of blood vessels， respectively. The enzyme-linked immunosorbent assay （ELISA） was employed to determine the levels of tumor necrosis factor-α （TNF-α）， intercellular adhesion molecule-1 （ICAM-1）， interleukin （IL）-1β， and nitric oxide （NO） in the serum. Western blotting was employed to determine the expression of endothelial nitric oxide synthase （eNOS）， NF-κB p65， phospho-NF-κB p65 （p-NF-κB p65）， NLRP3， and Caspase-1 in the vascular tissue. ResultThe model group showed thickened endovascular membrane， proliferation and disarrangement of smooth muscle cells of the artery wall， obvious inflammatory cell infiltration， and narrowed luminal area. Jiedu Huoxue prescription and atorvastatin calcium tablets mitigated the pathological changes of the thoracic aorta in different degrees. After balloon injury， the endothelial coverage rate of the model group decreased significantly， while Jiedu Huoxue prescription and atorvastatin calcium tablets increased the reendothelialization rate （P<0.05）. Compared with the shame surgery group， the model group showed elevated levels of TNF-α， ICAM-1， and IL-1β （P<0.01） and lowered NO level （P<0.01） in the serum. In addition， the model group presented down-regulated protein level of eNOS （P<0.01） and up-regulated phosphorylation of pyroptosis-associated proteins NLPR3， Caspase-1， and NF-κB p65 in the vascular tissue （P<0.05， P<0.01）. Compared with the model group， Jiedu Huoxue prescription and atorvastatin calcium tablets lowered TNF-α， ICAM-1， and IL-1β levels （P<0.05， P<0.01） and elevated the NO level in the serum （P<0.05， P<0.01）. Moreover， the drugs up-regulated the expression of eNOS （P<0.01） and down-regulated the expression of NLRP3， Caspase-1， and NF-κB p65 （P<0.05， P<0.01） in the vascular tissue. ConclusionJiedu Huoxue prescription can promote the reendothelialization and inhibit the intimal hyperplasia of vessels after balloon injury by regulating the NF-κB/NLRP3/Caspase-1 pathway to inhibit pyroptosis and reduce endothelial inflammatory injury.

Effect and mechanism of hyperthermia on cell apoptosis of laryngeal squamous cell carcinoma patients / 中华放射肿瘤学杂志

Objective:To evaluate the effect of hyperthermia on the apoptosis and the expression levels of cysteine-containing aspartate-specific protease-3 (Caspase-3) and phosphorylated protein kinase B (p-AKT) in laryngeal squamous cell carcinoma cells.Methods:A prospective study was conducted on 30 patients with laryngeal squamous cell carcinoma who were treated at the First Affiliated Hospital of Zhengzhou University from October, 2021 to October, 2022. Three times of hyperthermia were performed with a time interval of 24 h. The tumor tissue samples were collected from 30 patients before and after hyperthermia and divided into before hyperthermia group (group A ) and after hyperthermia group (group B). Self-control study mode was adopted for comrparative analysis. The cell apoptosis was detected by TUNEL assay. The expression levels of Caspase-3 and p-AKT in the tissues were detected by immunohistochemistry. Positive cell ratio and immunohistochemistry (IHC) score were recorded. Comparison between two groups was performed by paired t-test. The correlation between the degree of apoptosis and the changes of Caspase-3 and p-AKT molecules was assessed by Pearson correlation analysis. Results:No evident adverse reactions were observed in 30 patients after hyperthermia. The apoptosis index of laryngeal squamous cell carcinoma cells in group A was 2.37%±1.33%, and 4.27%±3.93% in group B ( P=0.006). In group A, the ratio of Caspase-3 positive cells in tumor tissues was 62.31%±19.49% and 80.79%±17.15% in group B ( P=0.001). The ratio of p-AKT positive cells in group A was 31.26%±19.30%, and 26.26%±15.86% in group B ( P=0.023). There was a positive correlation between the degree of apoptosis and the changes of Caspase-3 molecule ( r=0.544, P=0.002), but a negative correlation was noted between the degree of apoptosis and the changes of p-AKT molecule ( r=-0.434, P=0.017). Conclusion:Hyperthermia can promote the apoptosis of tumor cells in laryngeal squamous cell carcinoma, which may be related to Caspase-3 dependent apoptosis, and the inhibition of AKT phosphorylation is also involved in this process.

Birth weight of infants born to pregnant women living with human immunodeficiency virus and its associated factors / 中华传染病杂志

Objective:To investigate the birth weight (BW) of infants born to pregnant women living with human immunodeficiency virus (HIV) and its associated factors, and to provide more evidence for the prevention of mother-to-child transmission (PMTCT) in China.Methods:This study was a retrospective cohort study. Between January 2004 and December 2021, pregnant women living with HIV and their infants in Hubei Province were recruited and followed up, and clinical data were collected through hospital medical records and HIV/acquired immunodeficiency syndrome comprehensive response information management system. The multivariable linear regression was performed on the collected data to investigate associated influencing factors of BW.Results:In total, 531 pregnant women living with HIV (581 pregnancies) and 581 infants were enrolled. Of the 581 infants, 36 were HIV-positive, with a PMTCT rate of 6.2%. The mean BW of the infants was (3 075.0±470.2) gram. Protease inhibitor (PI) based-anti-retroviral therapy (ART) ( β=-0.1, 95% confidence interval ( CI)-188.2 to -37.1, P=0.004), ART in the first trimester( β=-0.1, 95% CI -201.9 to -65.5, P<0.001), infant HIV infection ( β=-0.1, 95% CI -310.4 to -68.2, P=0.002), hepatitis C virus infection ( β=0.1, 95% CI 71.2 to 410.4, P=0.005) and gestational age ( β=0.6, 95% CI 155.9 to 191.5, P<0.001) were associated with decreased BW. Conclusions:While improving the effectiveness of PMTCT for HIV, more attention should be paid to pregnant women who received ART in the first trimester and PI-based ART for preventing lower BW and improving maternal and infantile health.

Protease Production by Submerged Fermentation in Shake Flasks Using Bacillus sp. Isolated from the Soil

Proteases are one of the most industrially important enzymes, which account for about 60% of total enzyme market. Protease production by submerged fermentation in shake flasks using Bacillus sp. isolated from the soil was studied. Soil samples were collected from different locations within Chukwuemeka Odumegwu Ojukwu University, Uli, Anambra state. The soil samples were serially diluted and inoculated on sterilized skim milk agar plates. The plates were incubated at 30oC for 72 h. A clear zone around the colonies gave an indication of protease-producing bacteria isolates. The selected protease producers were subsequently used for shake flask fermentation in 50 ml sterile medium. Optimization study was conducted to determine the effect of carbon sources, nitrogen sources, trace elements, agitation rates and pH. Twenty one bacteria isolates were found to be active protease producers and isolates RS-5 and OS-9 had the highest zone of clearance of 13.5 and 12.1 mm respectively. The result of submerged production of protease by the bacteria isolates revealed that the isolates RS-5 and OS-9 accumulated maximum protease yield of 3.23 and 2.71 U/ml respectively. The isolates were Gram positive and endospore formers, and were identified as Bacillus sp. RS-5 and OS-9.The addition of Starch and maltose stimulated optimum protease production of 3.47 and 2.77 U/ml by Bacillus sp. RS-5 and OS-9 respectively. Beef extract enhanced maximum enzyme yield of 3.35 and 2.90 U/ml for Bacillus sp. RS-5 and OS-9 respectively. Maximum protease yield of 3.28 U/ml for Bacillus sp. RS-5 and 2.85 U/ml for Bacillus sp. OS-9 was obtained by the supplementation of 0.4 g/l of FeS04 respectively. The maximum protease yield was observed at agitation rate of 200 rpm for Bacillus sp. RS-5 and 170 rpm for Bacillus sp. OS-9. At pH8, protease accumulation was highest for Bacillus sp. RS-5 and OS-9. The study revealed that the soil harbours some protease-producing bacteria strains and protease production can be greatly enhanced through optimization of process parameters.