Single extracellular vesicle research: From cell population to a single cell.

Extracellular vesicles (EVs) are secreted by cells with a membrane structure and complex components such as DNA, RNA and proteins. These biomolecules play an important role in cell communication, cell proliferation, cell migration, vascularization, immune response and other physiological and pathological processes. Most current research on EVs focused on populations of EVs. Heterogeneity of EVs is neglected. Considering the heterogeneity of single EVs may offer critical molecular insights into cell-cell interactions, it is necessary to enhance our understanding about molecular characteristics from EVs derived from cell population to a single EV of derived from a single cell. This transformation is expected to provide a new insight into the understanding of cellular biology and the accurate description of the law of disease progress. In this article, we review the current research progress of single EV analysis technology for single EVs derived from cell population (SECP) and discuss its main applications in biological and clinical medicine research. After that, we propose the development direction, main difficulties and application prospect of single EV analysis technology for single EVs derived from single cells (SESC) according to our own research work, to provide new perspectives for the field of EV research.

Discovery of LH10, a novel fexaramine-based FXR agonist for the treatment of liver disease.

Farnesoid X receptor (FXR) was considered as a promising drug target in the treatment of cholestasis, drug-induced liver injury, and non-alcoholic steatohepatitis (NASH). However, the existing FXR agonists have shown different degrees of side effects in clinical trials without clear interpretation. MET-409 in clinical phase Ⅲ, has been proven significantly fewer side effects than that of other FXR agonists. This may be due to the completely different structure of FEX and other non-steroidal FXR agonists. Herein, the structure-based drug design was carried out based on FEX, and the more active FXR agonist LH10 (FEX EC50 = 0,3 µM; LH10 EC50 = 0.14 µM)) was screened out by the comprehensive SAR studies. Furthermore, LH10 exhibited robust hepatoprotective activity on the ANIT-induced cholestatic model and APAP-induced acute liver injury model, which was even better than positive control OCA. In the nonalcoholic steatohepatitis (NASH) model, LH10 significantly improved the pathological characteristics of NASH by regulating several major pathways including lipid metabolism, inflammation, oxidative stress, and fibrosis. With the above attractive results, LH10 is worthy of further evaluation as a novel agent for the treatment of liver disorders.

Genome-resolved metagenomics using environmental and clinical samples.

Recent advances in high-throughput sequencing technologies and computational methods have added a new dimension to metagenomic data analysis i.e. genome-resolved metagenomics. In general terms, it refers to the recovery of draft or high-quality microbial genomes and their taxonomic classification and functional annotation. In recent years, several studies have utilized the genome-resolved metagenome analysis approach and identified previously unknown microbial species from human and environmental metagenomes. In this review, we describe genome-resolved metagenome analysis as a series of four necessary steps: (i) preprocessing of the sequencing reads, (ii) de novo metagenome assembly, (iii) genome binning and (iv) taxonomic and functional analysis of the recovered genomes. For each of these four steps, we discuss the most commonly used tools and the currently available pipelines to guide the scientific community in the recovery and subsequent analyses of genomes from any metagenome sample. Furthermore, we also discuss the tools required for validation of assembly quality as well as for improving quality of the recovered genomes. We also highlight the currently available pipelines that can be used to automate the whole analysis without having advanced bioinformatics knowledge. Finally, we will highlight the most widely adapted and actively maintained tools and pipelines that can be helpful to the scientific community in decision making before they commence the analysis.

Design, synthesis, and biological evaluation studies of novel carboxylesterase 2 inhibitors for the treatment of irinotecan-induced delayed diarrhea.

Human carboxylesterase 2 (hCES2A), one of the most important serine hydrolases distributed in the small intestine and colon, plays a crucial role in the hydrolysis of various prodrugs and esters. Accumulating evidence has demonstrated that the inhibition of hCES2A effectively alleviate the side effects induced by some hCES2A-substrate drugs, including delayed diarrhea caused by the anticancer drug irinotecan. Nonetheless, there is a scarcity of selective and effective inhibitors that are suitable for irinotecan-induced delayed diarrhea. Following screening of the in-house library, the lead compound 01 was identified with potent inhibition on hCES2A, which was further optimized to obtain LK-44 with potent inhibitory activity (IC50 = 5.02 ± 0.67 µM) and high selectivity on hCES2A. Molecular docking and molecular dynamics simulations indicated that LK-44 can formed stable hydrogen bonds with amino acids surrounding the active cavity of hCES2A. The results of inhibition kinetics studies unveiled that LK-44 inhibited hCES2A-mediated FD hydrolysis in a mixed inhibition manner, with a Ki value of 5.28 µM. Notably, LK-44 exhibited low toxicity towards HepG2 cells according to the MTT assay. Importantly, in vivo studies showed that LK-44 significantly reduced the side effects of irinotecan-induced diarrhea. These findings suggested that LK-44 is a potent inhibitor of hCES2A with high selectivity against hCES1A, which has potential as a lead compound for the development of more effective hCES2A inhibitors to mitigate irinotecan-induced delayed diarrhea.

Design, synthesis, and biological studies of dual URAT1 inhibitor and FXR agonist based on benzbromarone.

With increased unhealthy dietary patterns and a sedentary lifestyle, the prevalence of hyperuricemia is growing rapidly, placing a tremendous burden on the public health system. Persistent hyperuricemia in extreme cases induces gout, gouty arthritis, and other metabolic diseases. Benzbromarone is a potent human urate transporter 1 (URAT1) inhibitor that is widely used as a uric acid-lowering drug. Recent studies indicated that benzbromarone can also activate farnesoid X receptor (FXR), whereas its agonistic activity on FXR is rather poor. Mounting evidence suggested that the etiology of gout is directly related to NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasomes, and FXR suppresses the expression of NLRP3 in various ways. Therefore, the dual URAT1 inhibitor and FXR agonist may exert synergistic effects on decreasing uric acid (UA) levels and inhibiting inflammation. To obtain a better dual URAT1 inhibitor and FXR agonist, we performed the structure-based drug design (SBDD) strategy to improve the FXR activation of benzbromarone by forming strong interactions with ARG331 in FXR binding pocket. All of these efforts lead to the identification of compound 4, which exerts better activity on FXR and uric acid-lowering effect than benzbromarone.

Design, synthesis and biological evaluation studies of novel anti-fibrosis agents bearing sulfoxide moiety.

Fibrosis, a chronic disease with high morbidity and mortality, is mainly characterized by excessive accumulation of extracellular matrix (ECM). At present, pathogenesis of fibrosis is incompletely understood, and there is an urgent need to develop safe and effective drugs. In this study, we designed and synthesized a series of novel small-molecule compounds through structural modification and fragment hybridization. Among them, a potential anti-fibrosis drug compd.1 was founded to be able to dose-dependently down-regulate ACTA2 and CTGF mRNA levels in human hepatic stellate cells (LX-2) treated with TGF-ß. In addition, compd.1 significantly improved the bridging fibrosis and collagen content in the CCl4-induced liver fibrosis mice model. Moreover, compd.1 reduced lung inflammation and fibrotic area in bleomycin-induced pulmonary fibrosis mice model. These findings suggested that compd.1 is a promising candidate for further anti-fibrosis researches, and extended chemical space might help us to explore better anti-fibrosis drug.

Comprehensive genomic variation profiling of cervical intraepithelial neoplasia and cervical cancer identifies potential targets for cervical cancer early warning.

BACKGROUND: To better understand the pathogenesis of cervical cancer (CC), we systematically analysed the genomic variation and human papillomavirus (HPV) integration profiles of cervical intraepithelial neoplasia (CIN) and CC. METHODS: We performed whole-genome sequencing or whole-exome sequencing of 102 tumour-normal pairs and human papillomavirus probe capture sequencing of 45 CCs, 44 CIN samples and 25 normal cervical samples, and constructed strict integrated workflow of genomic analysis. RESULTS: Mutational analysis identified eight significantly mutated genes in CC including four genes (FAT1, MLL3, MLL2 and FADD), which have not previously been reported in CC. Targetable alterations were identified in 55.9% of patients. In addition, HPV integration breakpoints occurred in 97.8% of the CC samples, 70.5% of the CIN samples and 42.8% of the normal cervical samples with HPV infection. Integrations of high-risk HPV strains in CCs, including HPV16, 18, 33 and 58, also occurred in the CIN samples. Moreover, gene mutations were detected in 52% of the CIN specimens, and 54.8% of these mutations occurred in genes that also mutated in CCs. CONCLUSION: Our results lay the foundation for a deep understanding of the molecular mechanisms and finding new diagnostic and therapeutic targets of CC.

Metabolomics-driven identification of adenosine deaminase as therapeutic target in a mouse model of Parkinson's disease.

Neuroinflammation is one of the driving forces of progressive neurodegeneration in Parkinson's disease (PD). The metabolomics approach has been proved highly useful in identifying potential therapeutic targets. Here, to identify inflammation-relevant treatment targets for PD, mass spectrometry-based untargeted metabolomics was applied to characterize metabolic changes in the striatum of mice with double-hit PD induced by lipopolysaccharide plus 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Seven days after the final MPTP administration, metabolites from the purine metabolism pathway, including adenosine, 1-methyladenosine, adenine, inosine, hypoxanthine, xanthine, xanthosine, and guanosine, were found to be significantly dysregulated. The metabolite-protein interaction network and changes in the concentration ratio of these metabolites indicated that adenosine and adenosine deaminase (ADA; EC 3.5.4.4) were the most promising therapeutic targets and adenosine augmentation might be a rational approach to slow PD progression. These findings were then verified in a subacute MPTP-induced PD mouse model treated with ADA inhibition alone or in conjunction with antagonism of adenosine A2A receptors (A2A R). Behavioral, biochemical, and immunohistochemical analysis demonstrated that ADA inhibition significantly ameliorated the MPTP-mediated motor disabilities, dopamine depletion, and dopaminergic cell death. Significantly enhanced neuroprotective effects were further observed when the ADA inhibitor was utilized in conjunction with an A2A R antagonist. Together, our study indicated for the first time that ADA inhibitors protected against neurodegeneration induced by the neurotoxin MPTP, and ADA inhibitors in combination with A2A R antagonists showed additive antiparkinsonian effects.

[Mechanism of Danzhi Jiangtang Capsules in treatment of diabetic macrovascular disease in GK rats based on correlation between microRNAs and inflammatory factors].

This study was aimed to investigate the mechanism of Danzhi Jiangtang Capsules( DJC) in the treatment of diabetic macrovascular disease in Goto-Kakizaki( GK) rats. The diabetic macrovascular disease rat model was induced by feeding high-fat and high-sugar combined with endothelial nitric oxide synthase( NOS) inhibitor N-nitro-L-arginine methyl ester( L-NAME)( 0. 1 g·L-1·d-1). According to the random array table,the model rats were randomly divided into the model group,DJC groups( 1 260,630,320 mg·kg-1),atorvastatin group( 105 mg·kg-1) and metformin group( 10 mg·kg-1),with 12 rats in each group. The rats received gavage administration for 8 weeks. Twelve Wistar rats were selected as the normal control group. The changes of body weight,water intake,blood glucose,plasma total cholesterol( TC),triglyceride( TG),high density lipoprotein( HDL-C),low density lipoprotein( LDL-C),interleukin( IL-1ß),IL-6,tumor necrosis factor( TNF-α),nitric oxide( NO),endothelin( ET-1) were observed in these rats. Aortic tissue was taken and the pathological changes were observed by HE staining. RT-PCR was used to detect the mRNA levels of IL-1ß,IL-6,and TNF-α in rat aorta. RT-PCR of the stem loop was used to detect the levels of miRNA-126,miRNA-155,miRNA-146 a,and miRNA-21 in rat plasma and aortic tissue. The canonical correlation between miRNAs and inflammatory factors was then analyzed. The results showed that DJC increased the rat body weight,lowered water intake,reduced the random blood glucose,reversed the rat aorta tissue damage,reduced serum TC,TG,LDL-C,ET-1,IL-1ß,IL-6,TNF-α,as well as miRNA-155,miRNA-146 a and miRNA-21 levels in serum,elevated plasma HDL-C,NO content,reduced the aorta mRNA of IL-1ß,IL-6,TNF-α,and the miRNA-155,miRNA-146 a and miRNA-21,elevated miRNA-126 expression in aorta. Aortic miRNA-126,miRNA-155,miRNA-146 a and miRNA-21 expression levels were typically correlated with the expression of inflammatory factors,among which miRNA-126 was negatively correlated,miRNA-155,miRNA-146 a and miRNA-21 were positively correlated with the factors. These results suggested that DJC had therapeutic effects on diabetic macrovascular diseases,and the mechanism of action may be related to the regulation of miRNA-126,miRNA-155,miRNA-146 a and miRNA-21 levels,as well as the reduction of inflammatory factors and vascular inflammatory response.

Integration of multienzyme co-immobilization and biomimetic catalysis in magnetic metal-organic framework nanoflowers for α-amylase detection in fermentation samples.

Multiple enzymes induce biological cascade catalysis is essential in nature and industrial production. However, the shortcomings of enzymes, including unsatisfactory stability, reusability, and sensitivity in harsh microenvironment, have restricted their broader use. Here, we report a facile method for fabricating a cascade system by combining the benefits of immobilized enzymes and biomimetic catalysis based on magnetic metal-organic framework nanoflowers (mMOFNFs). mMOFNFs prepared through the layered double hydroxide-derived strategy exhibited remarkable peroxidase-like activity and accessible amino interface, enabling it to serve not only as a reliable carrier for α-glucosidase and glucose oxidase fixation, but also as a nanozyme participating in cascade. On this basis, a colorimetric biosensor of excellent sensitivity and selectivity for α-amylase detection was constructed with a wide range (2-225 U L-1), low detection limit (2.48 U L-1), and rapid operation (30 min). This work provides a versatile strategy for establishing multi-enzyme cascade systems and rapid analysis of α-amylase.

CAPZB mRNA is a novel biomarker for cervical high-grade squamous lesions.

This study aimed to evaluate the potential of capping protein (actin filament) muscle Z-line subunit ß (CAPZB) messenger ribonucleic acid (mRNA) levels as a biomarker for distinguishing low-grade squamous intraepithelial lesions of the cervix (LSIL) from high-grade squamous intraepithelial lesions of the cervix (HSIL). We collected a total of 166 cervical exfoliated cells and divided them into five groups based on histopathological results. Each sample was divided into two portions, one for fluorescence in situ hybridization (FISH) detection and the other for bisulfite sequencing polymerase chain reaction (BSP) detection. We found that FISH detection of CAPZB mRNA mean fluorescence intensity (MFI) and BSP detection of CAPZB deoxyribonucleic acid (DNA) percentage of methylation rate (PMR) performed as biomarkers for distinguishing HSIL from LSIL, with an area under the receiver operating characteristic curve (AUC), sensitivity, specificity and cut-off value of 0.893, 81.25%, 80.39% and 0.616, 0.794, 64.06%, 81.37% and 0.454, respectively. Furthermore, FISH detection of CAPZB mRNA exhibited a greater AUC (0.893) for the detection of HSIL than the CAPZB DNA methylation method (0.794), indicating the CAPZB mRNA levels can be used as a biomarker for assessing cervical lesions.

Enzyme-integrated metal-organic framework platform for cascade detection of α-amylase.

As one of the most important industrial enzymes, α-amylase is widely used in food processing, such as starch sugar and fermentation, bringing high added value to industry of more than a trillion dollars. We developed a multi-enzyme system (Glu&Gox@Cu-MOF-74) prepared by embedding α-glucosidase (Glu) and glucose oxidase (Gox) into the biomimetic metal-organic framework Cu-MOF-74 using in situ encapsulation within 15 min at room temperature for efficient and sensitive detection of α-amylase activity. Benefitting from the remarkable peroxidase-mimicking property and rigid skeleton of Cu-MOF-74, the biocatalytic platform exhibited excellent cascade activity and tolerance in various extremely harsh environments compared to natural enzymes. On this basis, a cascade biocatalytic platform was constructed for the detection of α-amylase activity with wide linear range (5-100 U/L) and low limit of detection (1.45 U/L). The colorimetric cascade scheme is important for the sensitive and selective determination of α-amylase in complex fermentation samples, and the detection time is short (∼0.5 h). This work provides new ideas for the detection of α-amylase based on the cascade amplification method.

Allosteric mechanism of synergistic effect in α- and ß-amylase mixtures.

Alpha-amylase and beta-amylase coexist as mixtures in industrial production, and the two amylases have active synergistic effects when they approach each other. These effects are due to enhanced enzyme binding affinity for the substrate and the rate of particle hydrolysis. Here, we report the allosteric mechanism of this synergistic effect in α- and ß-amylase mixtures. The assay showed higher activity after mixing α- and ß-amylase. Molecular docking showed that α- and ß-amylase create a stable dual-enzyme complex with high binding energy, and that complex formation does not affect the exposure of respective active sites. ß-Amylase is specifically bound to the B domain of α-amylase, and the dynamic plasticity of the B domain makes it move spatially, and this adjustment leads to a more open conformation in the active site of α-amylase. Because the enzymes binding make the complex more stable, the degree to which the relative activity of the dual-enzyme complex is inhibited is significantly reduced. After enzyme hydrolysis, the products maltose and glucose accumulate and produce competitive inhibition, which explains the relative activity decrease of the later-stage dual-enzyme cooperation. Structural characterization by FT-IR and CD spectroscopy did not reveal significant changes in respective secondary structures after enzyme binding.

Dietary L-arabinose-induced gut dysbiosis exacerbates Salmonella infection outcome.

The gut microbiota is essential for providing colonization resistance against pathogens. Dietary sugars markedly shift the composition of the intestinal microbiota and alter host susceptibility to enteric infections. Here, we demonstrate the effect of L-arabinose on bacterial infection by using a mouse infection model with Salmonella enterica serovar Typhimurium (S. Tm). In the presence of microbiota, L-arabinose induces a dramatic expansion of Enterobacteriaceae, thereby decreasing the microbiota diversity and causing more severe systemic infection. However, L-arabinose supplementation does not alter the disease progression of Salmonella infection in a microbiota-depleted mouse model. More importantly, short-term supplementation of L-arabinose fails to exert anti-diabetic effects in Salmonella-infected hyperglycemia mice and still promotes infection. Overall, our work reveals that a high intake of dietary L-arabinose supports a bloom of Enterobacteriaceae in Salmonella-infected gut, further accelerating the process of systemic infection.IMPORTANCEL-arabinose is a promising natural sweetener and food additive for the regulation of hyperglycemia. Since diabetic subjects are more susceptible to infections, the safety of dietary L-arabinose in diabetic patients experiencing infection remains a concern. Our findings reveal that L-arabinose exacerbates Salmonella infection outcome by inducing gut microbiota dysbiosis in mice. High dietary intake of L-arabinose may be deleterious for diabetic individuals undergoing infection.

The metabolites of lactic acid bacteria: classification, biosynthesis and modulation of gut microbiota.

Lactic acid bacteria (LAB) are ubiquitous microorganisms that can colonize the intestine and participate in the physiological metabolism of the host. LAB can produce a variety of metabolites, including organic acids, bacteriocin, amino acids, exopolysaccharides and vitamins. These metabolites are the basis of LAB function and have a profound impact on host health. The intestine is colonized by a large number of gut microorganisms with high species diversity. Metabolites of LAB can keep the balance and stability of gut microbiota through aiding in the maintenance of the intestinal epithelial barrier, resisting to pathogens and regulating immune responses, which further influence the nutrition, metabolism and behavior of the host. In this review, we summarize the metabolites of LAB and their influence on the intestine. We also discuss the underlying regulatory mechanisms and emphasize the link between LAB and the human gut from the perspective of health promotion.

RT-nestRPA is a new technology for the rapid and sensitive detection of nucleic acid detection of pathogens used for a variety of medical application scenarios.

BACKGROUND: The effective detection of pathogens is of great importance for the diagnosis and treatment of infectious diseases. We have proposed the novel RT-nestRPA technique for SARS-CoV-2 detection, which is a rapid RNA detection technique with ultra-high sensitivity. RESULTS: The RT-nestRPA technology has a sensitivity of 0.5 copies/uL of synthetic RNA targeting the ORF7a/7b/8 gene or 1 copy/uL synthetic RNA targeting the N gene of SARS-CoV-2. The entire detection process of RT-nestRPA only takes only 20 min, which is significantly shorter than RT-qPCR (nearly 100 min). Additionally, RT-nestRPA is capable of detecting dual genes of SARS-CoV-2 and human RPP30 simultaneously in one reaction tube. The excellent specificity of RT-nestRPA was verified by analyzing twenty-two SARS-CoV-2 unrelated pathogens. Furthermore, RT-nestRPA had great performance in detecting samples treated with cell lysis buffer without RNA extraction. The innovative double-layer reaction tube for RT-nestRPA can prevent aerosol contamination and simplify the reaction operation. Moreover, the ROC analysis revealed that RT-nestRPA had high diagnostic value (AUC = 0.98), while the AUC of RT-qPCR was 0.75. SIGNIFICANCE: Our current findings suggested that RT-nestRPA could serve as a novel technology for nucleic acid detection of pathogens with rapid and ultrahigh sensitive features used in various medical application scenarios.

Rapid and ultrasensitive activity detection of α-amylase based on γ-cyclodextrin crosslinked metal-organic framework nanozyme.

α-Amylase plays a significant part in fermentation and the food industry, as this enzyme effectively regulates the content of different sugars in brewing systems and affects the yield and quality of alcoholic beverages. Nevertheless, current strategies suffer from unsatisfactory sensitivity and are time-consuming or are indirect methods which demand the assistance of tool enzymes or inhibitors. Therefore, they are unsuitable for the low bioactivity and non-invasive detection of α-amylase in fermentation samples. Rapid, sensitive, facile, and direct detection method of this protein remains challenging in actual applications. In this work, a nanozyme-based α-amylase assay was constructed. The colorimetric assay used the interaction between α-amylase and γ-cyclodextrin (γ-CD) which crosslinks MOF-919-NH2. The determination mechanism bases on the hydrolysis of γ-CD by α-amylase, resulting in increased peroxidase-like bioactivity of the released MOF nanozyme. The detection limit was 0.12 U L-1 with a wide linear range (0-200 U L-1) and excellent selectivity. Additionally, the proposed detection method was successfully utilized in distilled yeasts to verify analytical capability in fermentation samples. The exploration of this nanozyme-based assay not only provides a convenient and effective strategy for enzyme activity determination in food industry, but also has promotion significance in clinical diagnosis and pharmaceutical production.

EPHX1 and GSTP1 polymorphisms are associated with COPD risk: a systematic review and meta-analysis.

Background: Chronic obstructive pulmonary disease (COPD) affects approximately 400 million people worldwide and is associated with high mortality and morbidity. The effect of EPHX1 and GSTP1 gene polymorphisms on COPD risk has not been fully characterized. Objective: To investigate the association of EPHX1 and GSTP1 gene polymorphisms with COPD risk. Methods: A systematic search was conducted on 9 databases to identify studies published in English and Chinese. The analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines (PRISMA). The pooled OR and 95% CI were calculated to evaluate the association of EPHX1 and GSTP1 gene polymorphisms with COPD risk. The I2 test, Q test, Egger's test, and Begg's test were conducted to determine the level of heterogeneity and publication bias of the included studies. Results: In total, 857 articles were retrieved, among which 59 met the inclusion criteria. The EPHX1 rs1051740 polymorphism (homozygote, heterozygote, dominant, recessives, and allele model) was significantly associated with high risk of COPD risk. Subgroup analysis revealed that the EPHX1 rs1051740 polymorphism was significantly associated with COPD risk among Asians (homozygote, heterozygote, dominant, and allele model) and Caucasians (homozygote, dominant, recessives, and allele model). The EPHX1 rs2234922 polymorphism (heterozygote, dominant, and allele model) was significantly associated with a low risk of COPD. Subgroup analysis showed that the EPHX1 rs2234922 polymorphism (heterozygote, dominant, and allele model) was significantly associated with COPD risk among Asians. The GSTP1 rs1695 polymorphism (homozygote and recessives model) was significantly associated with COPD risk. Subgroup analysis showed that the GSTP1 rs1695 polymorphism (homozygote and recessives model) was significantly associated with COPD risk among Caucasians. The GSTP1 rs1138272 polymorphism (heterozygote and dominant model) was significantly associated with COPD risk. Subgroup analysis suggested that the GSTP1 rs1138272 polymorphism (heterozygote, dominant, and allele model) was significantly associated with COPD risk among Caucasians. Conclusion: The C allele in EPHX1 rs1051740 among Asians and the CC genotype among Caucasians may be risk factors for COPD. However, the GA genotype in EPHX1 rs2234922 may be a protective factor against COPD in Asians. The GG genotype in GSTP1 rs1695 and the TC genotype in GSTP1 rs1138272 may be risk factors for COPD, especially among Caucasians.

Comparability strategy and demonstration for post-approval production cell line change of a bevacizumab biosimilar IBI305.

High-producing cell line could improve the affordability and availability of biotherapeutic products. A post-approval production cell line change, low-titer CHO-K1S to high-titer CHO-K1SV GS-KO, was performed for a China marketed bevacizumab biosimilar IBI305. Currently, there is no regulatory guideline specifically addressing the requirements for comparability study of post-approval cell line change, which is generally regarded as the most complex process change for biological products. Following the quality by design principle and risk assessment, an extensive analytical characterization and three-way comparison was performed by using a panel of advanced analytical methods. Orthogonal and state-of-the-art techniques including nuclear magnetic resonance and high-resolution mass spectrometry were applied to mitigate the potential uncertainties of higher-order structures and to exclude any new sequence variants, scrambled disulfide bonds, glycan moiety and undesired process-related impurities such as host cell proteins. Nonclinical and clinical pharmacokinetics (PK) studies were conducted subsequently to further confirm the comparability. The results demonstrated that the post-change IBI305 was analytically comparable to the pre-change one and similar to the reference product in physicochemical and biological properties, as well as the degradation behaviors in accelerated stability and forced degradation studies. The comparability was further confirmed by comparable PK, pharmacodynamics, toxicological and immunogenicity profiles of nonclinical and clinical studies. The comparability strategy presented here might extend to cell line changes of other post-approval biological products, and particularly set a precedent in China for post-approval cell line change of commercialized biosimilars.

Discovery of novel carboxylesterase 2 inhibitors for the treatment of delayed diarrhea and ulcerative colitis.

Human carboxylesterase 2 (hCES2) is an enzyme that metabolizes irinotecan to SN-38, a toxic metabolite considered a significant source of side effects (lethal delayed diarrhea). The hCES2 inhibitors could block the hydrolysis of irinotecan in the intestine and thus reduce the exposure of intestinal SN-38, which may alleviate irinotecan-associated diarrhea. However, existing hCES2 inhibitors (except loperamide) are not used in clinical applications due to lack of validity or acceptable safety. Therefore, developing more effective and safer drugs for treating delayed diarrhea is urgently needed. This study identified a lead compound 1 with a novel scaffold by high-throughput screening in our in-house library. After a comprehensive structure-activity relationship study, the optimal compound 24 was discovered as an efficient and highly selective hCES2 inhibitor (hCES2: IC50 = 6.72 µM; hCES1: IC50 > 100 µM). Further enzyme kinetics study indicated that compound 24 is a reversible inhibitor of hCES2 with competitive inhibition mode (Ki = 6.28 µM). The cell experiments showed that compound 24 could reduce the level of hCES2 in living cells (IC50 = 6.54 µM). The modeling study suggested that compound 24 fitted very well with the binding pocket of hCES2 by forming multiple interactions. Notably, compound 24 can effectively treat irinotecan-induced delayed diarrhea and DSS-induced ulcerative colitis, and its safety has also been verified in subtoxic studies. Based on the overall pharmacological and preliminary safety profiles, compound 24 is worthy of further evaluation as a novel agent for irinotecan-induced delayed diarrhea.