S1PR1 serves as a viable drug target against pulmonary fibrosis by increasing the integrity of the endothelial barrier of the lung

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with unclear etiology and limited treatment options. The median survival time for IPF patients is approximately 2-3 years and there is no effective intervention to treat IPF other than lung transplantation. As important components of lung tissue, endothelial cells (ECs) are associated with pulmonary diseases. However, the role of endothelial dysfunction in pulmonary fibrosis (PF) is incompletely understood. Sphingosine-1-phosphate receptor 1 (S1PR1) is a G protein-coupled receptor highly expressed in lung ECs. Its expression is markedly reduced in patients with IPF. Herein, we generated an endothelial-conditional S1pr1 knockout mouse model which exhibited inflammation and fibrosis with or without bleomycin (BLM) challenge. Selective activation of S1PR1 with an S1PR1 agonist, IMMH002, exerted a potent therapeutic effect in mice with bleomycin-induced fibrosis by protecting the integrity of the endothelial barrier. These results suggest that S1PR1 might be a promising drug target for IPF therapy.

Microcápsulas y microesferas: una visión a la caracterización integral y aplicación para la liberación de medicamentos biotecnológicos / Microcapsules and microspheres: A vision to integral characterization and applications for biotechnological drugs delivery

Resumen Los microacarreadores basados en microcápsulas y microesferas han sido ampliamente estudiados y ensayados para controlar la liberación de medicamentos biotecnológicos (MB), disminuyendo la dosificación o modificando la vía de administración. Los métodos para la obtención de microacarreadores, son complejos y variados, por lo que es necesario determinar los requisitos mínimos que debe cumplir el sistema. El objetivo de este trabajo fue establecer las principales características que deben ser evaluadas en los microacarreadores para garantizar que la actividad biológica de los medicamentos biotecnológicos permanezca intacta a través del proceso de microencapsulación y, por lo tanto, que la seguridad del MB (desarrollo de reacciones inmunes) se mantenga inalterada. Las características a evaluar de un microacarreador deben describir las propiedades del material, tamaño y forma del sistema, carga de la partícula, funcionalidad, eficiencia de la microencapsulación y la cinética de liberación. Mientras que la integridad de los MB puede ser evaluada a partir de parámetros críticos de calidad: estructura y función biológica del MB, pureza del producto, presencia de agregados de alto peso molecular, estructura de orden superior y ensayos de actividad biológica. La caracterización de los microacarreadores debe enfocarse en la seguridad del biopolímero y proteínas ensayadas.

Abstract Microcarriers based on microcapsules and microspheres have been widely studied and tested to control the release of biotechnological drugs (BD), diminishing the dosage or modifying the route of administration. The methods for obtaining microcarriers are complex and varied, so it is necessary to determine the minimum characteristics with which the system must comply. The aim of this work was to establish the main characteristics that should be evaluated in the microcarriers in order to guarantee that the biological activity of biotechnological drugs remains intact through the microencapsulation process, and therefore the safety of the BD (development of immune reactions) remains unaltered. The characteristics of a microcarrier to be evaluated must describe the properties of the material, the size and shape of the system, the particle load, functionalization, the microencapsulation efficiency, and the kinetics of liberation. Whereas the integrity of BD can be evaluated by critical quality parameter such as: structure and biological function of the BD, product purity, presence of high molecular weight aggregations, higher order structure and biological activity tests. The characterization of the microcarriers must focus on the safety of the biopolymer and proteins tested.

In silico analysis of the effects of disease-associated mutations of b-hexosaminidase A in Tay–Sachs disease

Tay–Sachs disease (TSD), a deficiency of b-hexosaminidase A (Hex A), is a rare but debilitating hereditary metabolic disorder. Symptoms include extensive neurodegeneration and often result in death in infancy. We report an in silico study of 42 Hex A variants associated with the disease. Variants were separated into three groups according to the age of onset: infantile (n=28), juvenile (n=9) and adult (n=5). Protein stability, aggregation potential and the degree of conservation of residues were predicted using a range of in silico tools. We explored the relationship between these properties and the age of onset of TSD. There was no significant relationship between protein stability and disease severity or between protein aggregation and disease severity. Infantile TSD had a significantly higher mean conservation score than nondisease associated variants. This was not seen in either juvenile or adult TSD. This study has established that the degree of residue conservation may be predictive of infantile TSD. It is possible that these more highly conserved residues are involved in trafficking of the protein to the lysosome. In addition, we developed and validated software tools to automate the process of in silico analysis of proteins involved in inherited metabolic diseases. Further work is required to identify the function of well-conserved residues to establish an in silico predictive model of TSD severity

Improving proteolytic stability of Npu DnaE C-fragment in Escherichia coli expression system / 中国药科大学学报

@#Naturally split Npu DnaE intein can mediate rapid trans-splicing and C-cleavage, which is of great use in many aspects of protein engineering. However, the degradation of NpuC during expression and purification reduces the yield and purity of recombinant protein. N2C, an extended NpuN2-containing N-terminal NpuC fragment, was constructed to improve NpuC stability. N2C was expressed in BL21(DE3) and purified by affinity chromatography. The degradation ratio was calculated by ImageJ, and the factors affecting the C-terminal cleavage reaction of intein, such as temperature, DTT concentration and N/C ratio, were also investigated. The results showed that N2C lowered the proportion of degradation to 2.7%-7.2% and the yield of C-terminal cleavage reached 90% in 30 min at 37 °C with an N/C ratio of 5∶1 catalyzed by 1 mmol/L DTT. N2C can not only improve the stability of NpuC in Escherichia coli expression system, but also retain the activity of C-terminal cleavage reaction, which is of great significance for its application in protein purification.

The insertion of bioactive peptides at the C-terminal end of an 11S globulin changes the structural stability and improves the antihypertensive activity

BACKGROUND: The 11S globulin from amaranth is the most abundant storage protein in mature seeds and is well recognized for its nutritional value. We used this globulin to engineer a new protein by adding a four valinetyrosine antihypertensive peptide at its C-terminal end to improve its functionality. The new protein was named AMR5 and expressed in the Escherichia coli BL21-CodonPlus(DE3)-RIL strain using a custom medium (F8PW) designed for this work. RESULTS: The alternative medium allowed for the production of 652 mg/L expressed protein at the flask level, mostly in an insoluble form, and this protein was subjected to in vitro refolding. The spectrometric analysis suggests that the protein adopts a ß/α structure with a small increment of α-helix conformation relative to the native amaranth 11S globulin. Thermal and urea denaturation experiments determined apparent Tm and C1/2 values of 50.4°C and 3.04 M, respectively, thus indicating that the antihypertensive peptide insertion destabilized the modified protein relative to the native one. AMR5 hydrolyzed by trypsin and chymotrypsin showed 14- and 1.3-fold stronger inhibitory activity against angiotensin I-converting enzyme (IC50 of 0.034 mg/mL) than the unmodified protein and the previously reported amaranth acidic subunit modified with antihypertensive peptides, respectively. CONCLUSION: The inserted peptide decreases the structural stability of amaranth 11S globulin and improves its antihypertensive activity.

TRIM25 enhances EGFR stability and signaling activity to promote lung cancer progression / 药学学报

Mutation and amplification of epidermal growth factor receptor (EGFR), one of the most important driver gene, are both reported to participate in the regulation of lung cancer development and progression. Here we investigated the effect and molecular mechanism of tripartite motif 25 (TRIM25) in the regulation of development of lung cancer. CCK-8 and Transwell assays were used to explore the tumor-promoting effect of TRIM25. Results showed that knockdown of TRIM25 significantly inhibited cell proliferation (34% inhibition rate) and invasion (42% inhibition rate). Gene set enrichment analysis (GSEA), Western blot and immunohistochemistry were adopted to detect the effect of TRIM25 on EGFR expression and its downstream signal activity. The results explained that TRIM25 not only up-regulated the expression level of EGFR, but also promoted EGFR signal activation. Co-immunoprecipitation, real-time PCR and cycloheximide (CHX) inhibit protein degradation assays were employed to explore the molecular mechanism of TRIM25 in regulating EGFR stability. Preliminary exploration results indicate that TRIM25 increases the expression level of EGFR and activates its downstream signaling activity through promoting K63-linked ubiquitination of EGFR. Restoration of EGFR expression rescues the phenotype of TRIM25 depletion. In A549 cells, overexpression of EGFR increased cell proliferation rate 1.5-fold and invasion rate 1.6-fold compared with knockdown of TRIM25 cells. Similarly, in H1975 cells, cell proliferation rate was enhanced 2-fold and invasion rate was improved 1.7-fold. These data suggest that TRIM25 promotes lung cancer development via maintaining EGFR stability and continuous EGFR signaling activation. The human lung cancer tissues were obtained from lung cancer patients at Cancer Hospital Chinese Academy of Medical Sciences. Informed consent was obtained from all participants in accordance with the Declaration of Helsinki. The study was approved by the Ethics Committee of the Cancer Hospital Chinese Academy of Medical Sciences.

The preparation and evaluation of CRP trueness verificator: homogeneity, stability and commutability / 中华检验医学杂志

Objective To prepare the trueness verification materials of C-reactive protein (CRP) and evaluate its homogeneity, stability and commutability. Methods The high and low CRP concentrations trueness verification materials were from patient leftover sera which were pooled, mixed thoroughly, filtered and aliquoted. The homogeneity, stability and commutability of these materials were evaluated according to CNAS(China National Accreditation Service for Conformity Assessment, CNAS)-GL29:2010 "Reference materials-General and statistical principles for certification (ISO Guide35:2006)"and the Clinical and Laboratory Standards Institute (CLSI) EP30A. The trueness verification materials were used to evaluate the commutability in 10 clinical CRP detection systems, using forty-five patients' leftover sera with different CRP concentration evaluated by Deming regression in EP30A of CLSI. Meanwhile, the commutability of dilution series of ERM DA-474/IFCC were evaluated using the same method. Results A total of two CRP concentration level trueness verification materials were prepared, with high and low concentration levels of 754 and 743 vials, 1 ml each, respectively. The preparation showed good homogeneity (F<F0.05(14,30);On the condition of room temperature, 2-8 ℃ and -80 ℃, these materials were stable for 7 days and 44 months respectively, the slope of the linear equation of | b1 | less than t0.95,n-2 · s(b1), there was no statistically significant difference between the slope and zero, the stability is satisfied. The materials and the dilution series of ERM-DA 474/IFCC also showed good commutability among patient sera in 10 systems. Conclusions The trueness verification materials of C-reactive protein (CRP) showed good homogeneity, stability and commutability. The dilution series ERM DA-474/IFCC also have good commutability. These provided experimental support for the value transfer and application of the trueness verification materials .

Mechanism of CCT2, a new downstream substrate of PDGFRα, on proliferation of tumor cells / 上海交通大学学报（医学版）

Objective: To study the molecular mechanism of chaperonin containing TCP1 subunit 2(CCT2), a new downstream substrate of platelet derived growth factor receptor α(PDGFRα), in tumorigenesis. Methods: Non-small cell lung cancer cell line H1703 was used. Western blotting was used to measure the phosphorylation of CCT2 upon PDGFRα inhibitor Gleevec treatment and PDGF stimulation. H1703 cells were divided into siCon group, siPDGFRα group and siCCT2 group; 48 h later, cell number counting was used to test the effect of CCT2 on cell growth after siRNA transfection. H1703 cells were divided into siCon group, siPDGFRα group, siAKT group and siCCT2 group; Western blotting was used to measure the protein level of PDGFRα and PARP. Cell fractionation was used to detect the cellular localization of CCT2 and co-immunoprecipitation was used to test the interaction between CCT2 and PDGFRα. Results: CCT2 phosphorylation was inhibited by Gleevec and induced by PDGF. Compared to the control group, the number of cells transfected by siCCT2 reduced by 30% (P=0.006). The protein level of PDGFRα was also decreased in siCCT2 transfected cells, whereas the cleavage of PARP was increased. CCT2 was localized in both cytoplasmic and membrane fractions and interacted with PDGFRα directly. Conclusion: CCT2 is a new downstream substrate of PDGFRα. CCT2 can promote tumor cells growth by interacting and stabilizing PDGFRα.

Solution pH jump during antibody and Fc-fusion protein thaw leads to increased aggregation / 药物分析学报

Freeze-thaw cycles impact the amount of aggregation observed in antibodies and Fc-fusion proteins. Various formulation strategies are used to mitigate the amount of aggregation that occurs upon putting a protein solution through a freeze-thaw cycle. Additionally, low pH solutions cause native antibodies to unfold, which are prone to aggregate upon pH neutralization. There is great interest in the mechanism that causes therapeutic proteins to aggregate since aggregate species can cause unwanted im-munogenicity in patients. Herein, an increase in aggregation is reported when the pH is adjusted from pH 3 up to a pH ranging from pH 4 to pH 7 during the thaw process of a frozen antibody solution. Raising the pH during the thaw process caused a significant increase in the percent aggregation observed. Two antibodies and one Fc-fusion protein were evaluated during the pH jump thaw process and similar ef-fects were observed. The results provide a new tool to study the kinetics of therapeutic protein ag-gregation upon pH increase.

The role of ubiquitination and deubiquitination in the regulation of cell junctions

Maintenance of cell junctions plays a crucial role in the regulation of cellular functions including cell proliferation, permeability, and cell death. Disruption of cell junctions is implicated in a variety of human disorders, such as inflammatory diseases and cancers. Understanding molecular regulation of cell junctions is important for development of therapeutic strategies for intervention of human diseases. Ubiquitination is an important type of post-translational modification that primarily regulates endogenous protein stability, receptor internalization, enzyme activity, and protein-protein interactions. Ubiquitination is tightly regulated by ubiquitin E3 ligases and can be reversed by deubiquitinating enzymes. Recent studies have been focusing on investigating the effect of protein stability in the regulation of cell-cell junctions. Ubiquitination and degradation of cadherins, claudins, and their interacting proteins are implicated in epithelial and endothelial barrier disruption. Recent studies have revealed that ubiquitination is involved in regulation of Rho GTPases' biological activities. Taken together these studies, ubiquitination plays a critical role in modulating cell junctions and motility. In this review, we will discuss the effects of ubiquitination and deubiquitination on protein stability and expression of key proteins in the cell-cell junctions, including junction proteins, their interacting proteins, and small Rho GTPases. We provide an overview of protein stability in modulation of epithelial and endothelial barrier integrity and introduce potential future search directions to better understand the effects of ubiquitination on human disorders caused by dysfunction of cell junctions.

Characterizing the conformational change process of bovine serum albumin solution by fluorescence parameters / 中国药学杂志

OBJECTIVE: To study the conformational change process of bovine serum albumin (BSA) in guanidinium chloride through evaluating the fluorescence parameters, thus to elucidate the phenomenon from molecular level and to establish the relationship between the conformation of protein and the environment. METHODS: Intrinsic tryptophan fluorescence, fluorescence quenching and fluorescence probes spectrophotometry were selected to study the denaturation process of BSA in guanidinium chloride. RESULTS: An attenuation of intensity was observed both in BSA and ANS-BSA conjugates with the increasing concentration of guanidium chloride. A red shift on fluorescence emission peak occurred in the ANS-BSA conjugates, while the same result appeared in BSA only after a blue shift. The fluorescence quenching constant Ksv reduced to its minimum 3.469 × 10 L · mol-1 · s-1 in 0.5 mol · L-1 guanidium. CONCLUSION: It was shown that the denaturation process of BSA in guanidinium chloride was consistent with a three-state model, and the conformational change of the binding site on BSA of ANS was much more sensitive than that of tryptophane residue.

Long-Term Stability of Selected Serum Biomarkers in Leftover Samples / 임상검사와정도관리

BACKGROUND: The purpose of this study was to assess the quality of long-term-stored leftover blood samples, and to evaluate the long-term stability of selected serum biomarkers such as proteins, enzymes, electrolytes, and tumour markers. METHODS: Stored blood samples were transferred to our biobank after being used to conduct tests for routine medical examinations in one health care institution, and were preserved at or below -70degrees C for 4 years. We analysed 24 biomarkers whose levels had been reported 4 years ago and tested them using the same analyser, reagents, and methods by utilizing an ADVIA Centaur Immunoassay System (Siemens Healthcare Diagnostics, USA) or an ADVIA 2400 Chemistry System (Siemens, USA). RESULTS: A total of 15 out of the 24 tested biomarkers showed significant differences in paired Student t-tests (P0.975). Two biomarkers, creatinine and rheumatoid arthritis factor, showed no significant differences but were poorly correlated with previously analysed data. Aspartate aminotransferase, alanine aminotransferase, hepatitis B virus (HBV) surface antigen, and insulin levels were discordant according to their reference ranges. A total of 3 biomarkers, C-reactive protein, cancer antigen 125, and HBV surface antibody, showed no significant differences and good correlations without discordant data. CONCLUSIONS: Our findings showed that long-term storage for more than 4 years can result in a considerable bias for variable biomarkers. Only 3 of the 24 biomarkers evaluated were found to be stable biomarkers. Long-term storage of leftover samples is not recommended for most chemical analyses.

Assessing protein stability of the dimeric DNA-binding domain of E2 human papillomavirus 18 with molecular dynamics

The objective of this study is to understand the structural flexibility and curvature of the E2 protein of human papillomavirus type 18 using molecular dynamics (6 ns). E2 is required for viral DNA replication and its disruption could be an anti-viral strategy. E2 is a dimer, with each monomer folding into a stable open-faced â-sandwich. We calculated the mobility of the E2 dimer and found that it was asymmetric. These different mobilities of E2 monomers suggest that drugs or vaccines could be targeted to the interface between the two monomers.

Relation of C-reactive protein to the stability of coronary artery lesions and major adverse cardiac events / 中国实用内科杂志

Objective To observe the relationship between C-reactive protein (CRP) and the stability of coronary artery lesions and major adverse cardiac events.Methods By using coronary arteriography,coronary heart disease was diagnosed in 30 stable angina patients and 45 unstable ones.serum CRP and troponin T (cTnT) levels were measured on 0hs,6hs,24hs,48hs and 7days after hospital admission.The patients were divided into two groups according to the absence or presence of major adverse cardiac events.Results There was no relationship between CRP level and the severity of coronary artery lesions,whereas the CRP level of unstable angina(3.9?0.4 mg/L)was much higher than that of stable angina(2.2?0.3 mg/L),P

Exploring the Antifungal Activity of Bacillus amyloliquefaciens NK10.BAhjaWT / 微生物学通报

Bacillus are well known antibiotic producers. In this study,dozens of Bacillus strains from different sources were screened. Among them,a strain with strong antifungal activity was found. With 16S rDNA test and Biolog assay,this strain was identified to be Bacillus amyloliquefaciens. The fermentation conditions were optimized in small conical flasks. After ammonium sulfate salting out,dialysis,freezing vacuum dehydration,the crude protein extracts were obtained. The thermal stability,pH stability,protease stability,ion stability and antifungal spectrum of this protein were studied further. Scanning electronic microscope was also used to explore the antifungal mechanism.