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Biomedical subjects

Jie Wen

Publications and source records attributed to Jie Wen.

At least 19 recordsLinked to original sources

A Novel Homozygous Mutation in ARL2BP Causes Multiple Morphological Abnormalities of the Flagella and Primary Ciliary Dyskinesia.

Primary ciliary dyskinesia (PCD) and multiple morphological abnormalities of the sperm flagella (MMAF) frequently co-occur in male infertility. However, the genetic basis of this syndromic presentation remains unclear. Using whole-exome sequencing, we identified a novel homozygous ARL2BP splice-site mutation (c.294-2A>G) in a 23-year-old infertile male from a consanguineous family who presented with syndromic PCD and MMAF. This variant causes aberrant pre-mRNA splicing and triggers nonsense-mediated mRNA decay, resulting in the complete absence of ARL2BP protein expression. Transmission electron microscopy revealed extensive disorganization of flagellar axonemes with consistent central pair (CP) microtubule depletion and disorganization of peripheral doublets. Immunofluorescence confirmed a severe deficiency of the CP protein SPAG6 in the sperm flagella. Notably, the patient presented without retinal symptoms. Given that ARL2BP-related retinitis pigmentosa generally emerges during the third decade, long-term ophthalmological follow-up is essential to detect delayed-onset retinal degeneration. In conclusion, these findings confirm ARL2BP as a causative gene for both PCD and MMAF, expanding the genotypic and phenotypic spectrum of ciliopathies.

Humans↗

Genetic evidence that advanced COVID-19 accelerates longitudinal brain atrophy: A Mendelian randomization study.

Coronavirus disease 2019 (COVID-19) was reported to persist long-term in the brain and leave several long-term neurologic sequelae. However, the causal relationship between COVID-19 and brain aging is still unknown. The genome-wide association study (GWAS) data on COVID-19 phenotypes (susceptibility, hospitalization, and severity), involving a total of 5,779,391 participants, were collected from the COVID-19 Host Genetics Initiative. In addition, GWAS data on longitudinal changes in 15 brain structures, assessed via magnetic resonance imaging across the lifespan, were sourced from the ENIGMA Consortium and involved 15,640 participants. Two-sample Mendelian randomization was conducted to infer the causal relationship between COVID-19 and longitudinal brain changes. Multi-trait GWAS meta-analysis, colocalization, and fine-mapping analyses were performed to identify shared genetic etiologies. H3K27me3 ChIP-seq was used to evaluate the regulatory effect of colocalized loci. Two-step Mendelian randomization was applied to explore potential mediating mechanisms across multi-omics layers, including proteomics, metabolomics, and immunomics. Our results showed that COVID-19 hospitalization (β = -262.405, P = .041) and severity (β = -177.676, P = .049) were genetically associated with atrophied volume of total brain during longitudinal change. This suggests that individuals with advanced COVID-19 may be more susceptible to accelerated global brain aging. Caudate was genetically affected by all COVID-19 phenotypes. Seven variants were shared between advanced COVID-19 and global brain aging. rs117169628 was colocalized between advanced COVID-19 and global brain aging, and exerted an inhibitory effect on CDH15 expression, further strengthening the causality. Six metabolites, 1 protein, and 1 immune trait were identified as potential mediators. Our study indicates that advanced COVID-19 might be genetically associated with accelerated brain aging. Brain health should be paid more attention in long COVID-19.

Humans↗

Analysis and validation of abnormal signaling pathways and immune cell infiltration characteristics in digestive system cancers based on peroxisome-related genes.

BACKGROUND: Although emerging evidence suggests a role for peroxisomes in tumorigenesis, their functions in digestive cancers remain unclear. This study aims to investigate the association between peroxisomes and digestive tract tumors. METHODS: To systematically investigate peroxisomal functions in digestive cancers, we first constructed and validated tumor-specific prognostic signatures based on peroxisome-related genes (PRGs) through univariate Cox, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analyses. We then characterized the tumor immune microenvironment (TIME) with CIBERSORT, X-CELL, and EPIC algorithms, and identified tumor-specific and common signalings via Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA). Focusing on hepatocellular carcinoma (HCC), we experimentally validated peroxisome-related therapeutic responses by profiling signature genes in radioresistant cells and an orthotopic transarterial chemoembolization (TACE) rat model. PEX13 knockdown further assessed peroxisomal role in radiosensitivity and targeted therapy response. Clinical relevance of PEX13 was evaluated in HCC cohort. Single-cell RNA sequencing dataset and lipidomics further revealed peroxisomal mechanisms in HCC progression. Finally, peroxisomal function in colorectal cancer (CRC) was validated in vitro. RESULTS: Novel peroxisome-related prognostic signatures demonstrated strong predictive power in HCC, colon adenocarcinoma, rectal adenocarcinoma, pancreatic adenocarcinoma, gastric adenocarcinoma, esophageal adenocarcinoma, esophageal squamous cell carcinoma, and cholangiocarcinoma. High-risk patients displayed an immunosuppressive microenvironment, characterized by increased infiltration of regulatory T cells, M2 macrophages, Th2 cells, or cancer-associated fibroblasts, or Th1 cells' reduction. Peroxisomes engaged in several distinct yet convergent pathways, most notably "positive regulation of response to stimuli". HCC prognostic genes were dynamically regulated in response to therapeutic stimuli, including radiotherapy, targeted therapy, and TACE. Clinically, the expression of PEX13 was markedly upregulated in tumor tissues from therapy-resistant HCC patients. Mechanistically, peroxisomal dysfunction induced by silencing PEX13 in HCC or UBE2D2 in CRC may overcome therapeutic resistance (radiotherapy/ lenvatinib resistance in HCC, radioresistance in CRC) through reprogramming lipid metabolism. CONCLUSIONS: Peroxisomes act as pivotal regulators of digestive cancer progression by modulating signaling pathways, the TIME, therapeutic resistance, and lipid metabolism. Targeting peroxisomal function, particularly in high-risk subgroups of HCC and CRC, warrants further exploration as a promising therapeutic strategy.

Peroxisomes↗

Causal relationships between somatic movement, brain structures, and mental well-being: A multi-stage Mendelian randomization study.

BACKGROUND: While the relationships between somatic movement, mental well-being, and brain health have been well established, the causal nature and underlying mechanisms of such associations remain incompletely understood. METHODS: By applying multi-stage Mendelian randomization to multi-source summary data derived from genome-wide association studies, we examined the causal effects of 4 somatic movement measures on 2 mental well-being indices and 13 types of brain structures, followed by testing the mediating roles of brain structures in accounting for the causal associations between somatic movement and mental well-being. RESULTS: Two-sample Mendelian randomization revealed that more physical activity was causally associated with greater mental well-being (life satisfaction and positive affect), while more sedentary behavior (longer leisure screen time and more sedentary behavior at work) with lower mental well-being. With respect to brain structures, sedentary behavior was causally linked to decreased volume, surface area, and local gyrification index in distributed cortical regions. Remarkably, decreased surface area of the piriform cortex was found to mediate the causal associations between sedentary behavior and lower mental well-being. CONCLUSIONS: Our findings not only complement and extend earlier reports on the associations of somatic movement with mental well-being and brain health by further resolving the causality but also help elucidate the neural mechanisms by which sedentary behavior adversely affects mental well-being.

Humans↗

Physical and functional interactions between Cas and c-Src induce tamoxifen resistance of breast cancer cells through pathways involving epidermal growth factor receptor and signal transducer and activator of transcription 5b.

High expression of the adaptor molecule Cas has been linked to resistance to the antiestrogen tamoxifen, both in tissue culture and in human tumors. The aim of this study was to elucidate the mechanism(s) by which overexpression of Cas confers resistance to tamoxifen. Cas overexpression in MCF-7 breast cancer cells was shown to alleviate both tamoxifen-mediated growth inhibition and induction of apoptosis. This enhancement of cell proliferation/survival occurred in the absence of detectable effects on estrogen receptor (ER) transcriptional activity under conditions where tamoxifen was present, indicating that Cas-dependent tamoxifen resistance is not the result of a switch to an ER-negative phenotype or enhanced responses to the partial agonist activity of tamoxifen. Instead, we present evidence, suggesting that Cas promotes tamoxifen resistance by deregulation of alternative cell proliferation pathways, particularly those mediated through enhanced c-Src protein tyrosine kinase activity arising from Cas/c-Src interactions. Overexpression of Cas was found to drive endogenous c-Src into complex with Cas, a process that has been shown previously to cause up-regulation of c-Src tyrosine kinase activity. MCF-7 cells overexpressing Cas exhibited increased phosphorylation of two c-Src substrates, Tyr845 in the kinase domain of the epidermal growth factor receptor (EGFR) and signal transducer and activator of transcription (STAT) 5b. Importantly, Cas-dependent protection from the antiproliferative effects of tamoxifen was reversed by the expression of dominant inhibitory variants of these substrates (Y845F EGFR and COOH-terminally truncated STAT5b). Based on these findings, we suggest that the Cas/c-Src/EGFR/STAT5 signaling axis is a major regulator of tamoxifen-resistant breast cancer cell growth and survival.

Animals↗

Enhanced extracellular matrix production and differentiation of human embryonic germ cell derivatives in biodegradable poly(epsilon-caprolactone-co-ethyl ethylene phosphate) scaffold.

Extracellular environment regulates cell behavior and also influences the differentiation of stem cells. Two cell lines of pluriopotent human embryonic germ cell derivatives (EBD cells) were cultured on a biodegradable poly(epsilon-caprolactone-co-ethyl ethylene phosphate) (PCLEEP) and non-degradable cellulose acetate scaffold. Their cell behaviors including proliferation, differentiation, cell distribution and extracellular matrix production were studied for 4 weeks and 10 months. The proliferation of the EBD cells was enhanced in both of the three-dimensional scaffolds in the first 5 weeks of culture, regardless of the material difference, compared to monolayer culture. While the gene expression profile remained multilineage for the EBD cells cultured in the cellulose acetate fibrous scaffold, much of the neuronal lineage markers were down-regulated in EBD cells cultured in the PCLEEP scaffold. On the other hand, extracellular matrix production was significantly enhanced in the PCLEEP scaffold. The study showed that the polymer substrate could influence the differentiation and growth of pluripotent stem cells in the absence of exogenous biochemical signals.

Biocompatible Materials↗

Severe acute respiratory syndrome diagnostics using a coronavirus protein microarray.

To monitor severe acute respiratory syndrome (SARS) infection, a coronavirus protein microarray that harbors proteins from SARS coronavirus (SARS-CoV) and five additional coronaviruses was constructed. These microarrays were used to screen approximately 400 Canadian sera from the SARS outbreak, including samples from confirmed SARS-CoV cases, respiratory illness patients, and healthcare professionals. A computer algorithm that uses multiple classifiers to predict samples from SARS patients was developed and used to predict 206 sera from Chinese fever patients. The test assigned patients into two distinct groups: those with antibodies to SARS-CoV and those without. The microarray also identified patients with sera reactive against other coronavirus proteins. Our results correlated well with an indirect immunofluorescence test and demonstrated that viral infection can be monitored for many months after infection. We show that protein microarrays can serve as a rapid, sensitive, and simple tool for large-scale identification of viral-specific antibodies in sera.

Algorithms↗

The kiss of death: interrupted by NK-cell close encounters of another kind.

An intimate but deadly encounter between natural killer (NK) cells and transformed cells results in the delivery of cytotoxic molecules into tumor cells. New evidence reveals another intimate association, this time between NK cells and regulatory T cells, but this encounter opposes NK-cell tumoricidal activity. Through a contact-dependent mechanism involving transforming growth factor-beta, regulatory T cells provide an escape mechanism from NK-cell-mediated tumor surveillance.

Animals↗

TGF-beta: a mobile purveyor of immune privilege.

Functionally barricaded immune responses or sites of immune privilege are no longer considered dependent on specific anatomical considerations, but rather, they can develop in any location where immunoregulatory cells congregate and express or release products capable of deviating the host response to foreign antigens. Among the pivotal molecules involved in orchestrating these ectopic sites of immune suppression is transforming growth factor-beta (TGF-beta), a secreted and cell-associated polypeptide with a multiplicity of actions in innate and adaptive immunity. While beneficial in initiating and controlling immune responses and maintaining immune homeostasis, immunosuppressive pathways mediated by TGF-beta may obscure immune surveillance mechanisms, resulting in failure to recognize or respond adequately to self, foreign, or tumor-associated antigens. CD4+CD25+Foxp3+ regulatory T cells represent a dominant purveyor of TGF-beta-mediated suppression and are found in infiltrating tumors and other sites of immune privilege, where they influence CD8+ T cells; CD4+ T-helper (Th)1, Th2, and Th17 cells; natural killer cells; and cells of myeloid lineage to choreograph and/or muck up host defense. Defining the cellular sources, mechanisms of action, and networking that distinguish the dynamic establishment of localized immune privilege is vital for developing strategic approaches to diminish or to embellish these tolerogenic events for therapeutic benefit.

Animals↗

[Research on relationship between gene polymorphisms of interleukin-1 family and endometriosis].

OBJECTIVE: To investigate whether interleukin-1 beta (IL-1beta ) and interleukin-1 receptor antagonist (IL-1RA) gene polymorphisms are associated with endometriosis (EMs) in Chinese women. METHODS: One hundred and thirty-eight patients with EMs and 100 women without EMs were enrolled in the study. Polymorphisms for IL-1 beta-511 promoter, IL-1 beta exon 5, and IL-1RA were detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULT: There were no significant differences about the distribution of the genotypes and alleles of IL-1 beta -511 promoter and IL-1 beta exon 5 in two groups (P > 0.05). The frequencies of A1/A1, A1/A2, A1/A4 and A2/A2 of IL-1RA gene were 84.1 %, 12.3 %, 2.9 % and 0.7 % in EMs and 95 % , 4 % ,1 % and 0 % in controls, respectively (P=0.042). The A1, A2 and A4 alleles were 91.7 % , 6.9 % and 1.4 % in EMs and 97.5 % , 2 % and 0.5 % in controls (P=0.019). In comparison with the reference genotype, the wild A1/A1 homozygote, the odds ratio for A1/A2 was 3.48 (95 % CI: 1.13 - 10.69). Compared with the A1 allele, the odds ratio for the A2 allele was 3.66 (95 % CI: 1.23 - 10.94). CONCLUSION: Association between the IL-1 beta-511 promoter,IL-1 beta exon 5 polymorphisms and EMs in China is not found. However, the A2 allele of IL-1RA gene may be one of the risk factors for the Chinese women in Zhejiang Province to suffer EMs.

Adult↗

[Study of single nucleotide polymorphism of A-FABP gene and its association with fatness traits in chicken].

In this experiment, Beijing-You chicken was used to detect single nucleotide polymorphisms (SNPs) in A-FBAP gene and to study the correlation between its genotype and the trait of fat accumulation. The first exon of the gene was amplified by one pair of primers, and SNPs were detected by the technique of single strand conformation polymorphism (SSCP) and finally confirmed by sequencing. Results of analysis of variance showed that a significant difference existed among abdominal fat percentage, subcutaneous fat thickness and intramuscular fat contents in breast musculature with different genotypes (P<0.01). It implied that A-FABP gene could be a major effector gene or could be linked to gene(s) which significantly affect fat metabolism in chicken.

Adipocytes↗

[Review of bioactivities of natural cycloartane triterpenoids].

Cycloartane triterpenoids, which exist widely in nature, are mainly distributed in Astragalus (Leguminosae) species, Trib. Cimicifuga (Ranunculaceae) and Thalictrium (Ranunculaceae) species and possess various bioactivities. Along with the development of isolation techniques of phytochemistry, more and more this kind of compounds are isolated and identified. However, bioactivity researches on the compounds are relatively lagged behind. Most researches are still in screening level, deficient in mechanism elucidation, short of action proven in vivo and SAR analysis. The author summarized the bioactivity of this kind of compounds from all aspects: anti-tumor, anti-virus, antibacterial, anti-inflammation, immune-regulatory, cardiovascular system, hepatic protection and so forth. This will be benefit for the further research and development of the compounds.

Animals↗

Tal1/SCL binding to pericentromeric DNA represses transcription.

Tal1/SCL is a basic helix-loop-helix transcription factor critical for normal hematopoiesis. To understand the mechanisms underlying transcriptional regulation by Tal1/SCL, we combined an in vitro DNA binding strategy and an in vivo chromatin immunoprecipitation analysis to search for Tal1/SCL target regions in K562 erythroleukemia cells. A 0.4-kb genomic DNA clone containing two Tal1/SCL binding E-boxes and GATA- and SATB1-binding motifs (EEGS) was identified that localized to the pericentromeric region with high homology to satellite 2 DNA. Pericentric DNA is related to heterochromatin and gene inactivation. We found that Tal1/SCL could complex with the histone H3 lysine 9 (H3K9)-specific methyltransferase Suv39H1. Binding of Tal1/SCL to EEGS chromatin correlated with hypermethylation of H3K9 and the association of heterochromatin protein HP1 to this region. In Rep4 reporter gene assays, EEGS affected repression in a manner dependent on the expression level of Tal1/SCL that was accompanied by increased H3K9 methylation in chromatin associated with EEGS and a linked promoter. A specific histone deacetylase inhibitor, trichostatin A, relieved Tal1/SCL-mediated repression by EEGS. In addition, SATB1 bound EEGS chromatin and promoted Tal1/SCL EEGS-dependent repression. We expand the list of potential interacting partners for Tal1/SCL by demonstrating direct associations of Tal1/SCL with SATB1 and with Suv39H1. These results reveal a novel mechanism of action for Tal1/SCL and implicate heterochromatin-like silencing via a cis-acting binding motif for transcriptional repression.

Amino Acid Motifs↗

Stable immobilization of rat hepatocyte spheroids on galactosylated nanofiber scaffold.

Primary rat hepatocytes self-assemble into multi-cellular spheroids and maintain differentiated functions when cultured on a two-dimensional (2-D) substrate conjugated with galactose ligand. The aim of this study is to investigate how a functional nanofiber scaffold with surface-galactose ligand influences the attachment, spheroid formation and functional maintenance of rat hepatocytes in culture, as compared with the functional 2-D substrate. Highly porous nanofiber scaffolds comprising of fibers with an average diameter of 760 nm were prepared by electrospinning of poly(epsilon-caprolactone-co-ethyl ethylene phosphate) (PCLEEP), a novel biodegradable copolymer. Galactose ligand with a density of 66 nmol/cm(2) was achieved on the nanofiber scaffold via covalent conjugation to a poly(acrylic acid) spacer UV-grafted onto the fiber surface. Hepatocytes cultured on the galactosylated PCLEEP nanofiber scaffold exhibited similar functional profiles in terms of cell attachment, ammonia metabolism, albumin secretion and cytochrome P450 enzymatic activity as those on the functional 2-D substrate, although their morphologies are different. Hepatocytes cultured on galactosylated PCLEEP film formed 50-300 microm spheroids that easily detached from surface upon agitation, whereas hepatocytes cultured on galactosylated nanofiber scaffold formed smaller aggregates of 20-100 microm that engulfed the functional nanofibers, resulting in an integrated spheroid-nanofiber construct.

Adsorption↗

Use of the COOH portion of the nucleocapsid protein in an antigen-capturing enzyme-linked immunosorbent assay for specific and sensitive detection of severe acute respiratory syndrome coronavirus.

Antibody detection with a recombinant COOH portion of the severe acute respiratory syndrome (SARS) coronavirus nucleocapsid (N) protein, N13 (amino acids 221 to 422), was demonstrated to be more specific and sensitive than that with the full-length N protein, and an N13-based antigen-capturing enzyme-linked immunosorbent assay providing a convenient and specific test for serodiagnosis and epidemiological study of SARS was developed.

Antibodies, Viral↗

Retrospective serological investigation of severe acute respiratory syndrome coronavirus antibodies in recruits from mainland China.

Different assays were used to analyze 1,621 serum specimens collected from military recruits from the People's Republic of China in 2002 for severe acute respiratory syndrome (SARS) coronavirus antibodies. The results demonstrated that the subjects either had rarely been exposed to the virus before the 2003 SARS outbreak or had not been exposed but the nucleocapsid protein cross-reacted with other antibodies in humans.

Adolescent↗

SARS-associated coronavirus transmitted from human to pig.

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) was isolated from a pig during a survey for possible routes of viral transmission after a SARS epidemic. Sequence and epidemiology analyses suggested that the pig was infected by a SARS-CoV of human origin.

Animal Feed↗

[Study on the dynamics of IgG antibody in 311 patients with severe acute respiratory syndrome].

OBJECTIVE: To detect the level and dynamic change of severe acute respiratory syndrome (SARS)-coronavirus-specific IgG antibody in conavalescent SARS patients, and to provide information for prevention and vaccine development. METHODS: IgG antibody against coronavirus was detected by ELISA in the blood of 311 convalescent SARS patients for every 2 - 4 weeks. Stata 7.0 statistics software was used to analyse the results. RESULTS: IgG antibody was detected positive on each testing of all the convalescent patients and its peak appeared 35 days after recovery. IgG antibody level showed a 35.8% decrease within one year. CONCLUSION: Data showed that all the SARS convalescent patients had generated high level of specific IgG antibody against coronavirus in the early stage of recovery, but the antibody level declined along with the progress of convalescence, suggesting that the detection of the IgG antibody should go on until it disappeared.

Adolescent↗