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Biomedical subjects

Wei Zhou

Publications and source records attributed to Wei Zhou.

At least 37 records · Page 2Linked to original sources

Multipopulation GWAS for venous thromboembolism identifies novel loci followed by experimental validation in zebrafish.

Venous thromboembolisms (VTEs) are a leading cause of morbidity and mortality. Although many genetic risk factors have been identified, a substantial portion of the heritability remains unexplained. In this study, we employed a genome-wide association study (GWAS) for VTE across 9 international cohorts of the Global Biobank Meta-Analysis Initiative to address this question, along with in vivo functional validation. In this multipopulation GWAS (VTE cases, 27 987; controls, 1 035 290), 38 genome-wide significant loci were identified, 4 of which were potentially novel. For each autosomal locus, we performed gene prioritization using 7 independent, yet converging, lines of evidence. Through prioritization, we identified genes associated with VTE through GWAS and/or functional studies (eg, F5, F11, VWF, STAB2, PLCG2, TC2N), functionally validated those that did not have evidence other than GWAS (TC2N, TSPAN15), and discovered 1 not previously associated with coagulation (RASIP1). We evaluated the function of 6 prioritized genes with strong genetic evidence, including F7 as a positive control, using laser-mediated endothelial injury to induce thrombosis in zebrafish after CRISPR/Cas9 knockdown. From this assay, we have supportive evidence for the role of RASIP1 and TC2N in the modification of human VTE and suggestive evidence for STAB2 and TSPAN15. This study expands on the currently identified genomic architecture of VTE through biobank-based, multipopulation GWASs, in silico candidate gene predictions, and in vivo functional follow-up of candidate genes.

Zebrafish↗

Suppression of LKB1-mutant lung adenocarcinoma by natural killer cells from females.

BACKGROUND: This study addressed the enigma of sex differences in smoking-related lung cancer, particularly focusing on the low LKB1 mutation frequency in female patients with lung adenocarcinoma. METHODS: Sex bias was studied with a genetically engineered mouse model and various tail-vein injection models. Immune cells were analyzed by antibody-depletion study, flow cytometry, and immunofluorescence. The relevance of our findings to human disease was validated by evaluating various lung adenocarcinoma datasets. All statistical tests are 2-sided. RESULTS: A statistically significant percentage of females are resistant to LKB1-mutant tumor formation in our models, reflecting this sex difference in humans. Natural killer (NK) cells were identified as a critical factor in this sex-biased response. This sex difference was observed primarily in LKB1-mutant lung adenocarcinoma, probably due to their low major histocompatibility complex class I level, making them the ideal target for NK cells through the missing-self recognition. Although females resistant to LKB1-mutant lung adenocarcinoma formation did not have enhancement of any specific NK subpopulation, our immunofluorescence analysis revealed high numbers of NKs in female lungs even with the presence of LKB1-mutant lung adenocarcinoma. Our gene set enrichment analysis of The Cancer Genome Atlas-lung adenocarcinoma dataset also showed that female LKB1-mutant lung adenocarcinoma patients have a stronger NK-mediated response after adjusting for other male-female differences using the LKB1 wild-type lung adenocarcinoma dataset. CONCLUSION: Females have a stronger NK-mediated response against LKB1-mutant lung adenocarcinoma, which was present in our mouse model and the human lung adenocarcinoma dataset. This study revealed a novel role of NK cells in suppressing LKB1-mutant lung adenocarcinoma in females, which should be assessed in the clinical setting in the future.

Killer Cells, Natural↗

Plasma Proteomic Profiling Reveals ITGA2B as A Key Regulator of Heart Health in High-altitude Settlers.

Myocardial injury is a common disease in the plateau, especially in the lowlanders who have migrated to the plateau, in which the pathogenesis is not well understood. Here, we established a cohort of lowlanders comprising individuals from both low-altitude and high-altitude areas and conducted plasma proteomic profiling. Proteomic data showed that there was a significant shift in energy metabolism and inflammatory response in individuals with myocardial abnormalities at high altitude. Notably, integrin alpha-Ⅱb (ITGA2B) emerged as a potential key player in this context. Functional studies demonstrated that ITGA2B upregulated the transcription and secretion of interleukin-6 (IL-6) through the integrin-linked kinase (ILK)/nuclear factor-κB (NF-κB) signaling axis under hypoxic conditions. Moreover, ITGA2B disrupted mitochondrial structure and function, increased glycolytic capacity, and aggravated energy reprogramming from oxidative phosphorylation to glycolysis. Leveraging the therapeutic potential of traditional Chinese medicine in cardiac diseases, we discovered that tanshinone ⅡA (TanⅡA) effectively alleviated the myocardial injury caused by the abnormally elevated expression of ITGA2B and hypobaric hypoxia exposure in mice, thus providing a novel candidate therapeutic strategy for the prevention and treatment of high-altitude myocardial injury.

Animals↗

Exome-wide evidence of compound heterozygous effects across common phenotypes in the UK Biobank.

The phenotypic impact of compound heterozygous (CH) variation has not been investigated at the population scale. We phased rare variants (MAF &#x223c;0.001%) in the UK Biobank (UKBB) exome-sequencing data to characterize recessive effects in 175,587 individuals across 311 common diseases. A total of 6.5% of individuals carry putatively damaging CH variants, 90% of which are only identifiable upon phasing rare variants (MAF&#xa0;<&#xa0;0.38%). We identify six recessive gene-trait associations (p&#xa0;<&#xa0;1.68&#xa0;&#xd7;&#xa0;10-7) after accounting for relatedness, polygenicity, nearby common variants, and rare variant burden. Of these, just one is discovered when considering homozygosity alone. Using longitudinal health records, we additionally identify and replicate a novel association between bi-allelic variation in ATP2C2 and an earlier age at onset of chronic obstructive pulmonary disease (COPD) (p&#xa0;<&#xa0;3.58&#xa0;&#xd7;&#xa0;10-8). Genetic phase contributes to disease risk for gene-trait pairs: ATP2C2-COPD (p&#xa0;= 0.000238), FLG-asthma (p&#xa0;= 0.00205), and USH2A-visual impairment (p&#xa0;= 0.0084). We demonstrate the power of phasing large-scale genetic cohorts to discover phenome-wide consequences of compound heterozygosity.

Humans↗

Exome-wide evidence of compound heterozygous effects across common phenotypes in the UK Biobank.

Exome-sequencing association studies have successfully linked rare protein-coding variation to risk of thousands of diseases. However, the relationship between rare deleterious compound heterozygous (CH) variation and their phenotypic impact has not been fully investigated. Here, we leverage advances in statistical phasing to accurately phase rare variants (MAF ~ 0.001%) in exome sequencing data from 175,587 UK Biobank (UKBB) participants, which we then systematically annotate to identify putatively deleterious CH coding variation. We show that 6.5% of individuals carry such damaging variants in the CH state, with 90% of variants occurring at MAF < 0.34%. Using a logistic mixed model framework, systematically accounting for relatedness, polygenic risk, nearby common variants, and rare variant burden, we investigate recessive effects in common complex diseases. We find six exome-wide significant () and 17 nominally significant () gene-trait associations. Among these, only four would have been identified without accounting for CH variation in the gene. We further incorporate age-at-diagnosis information from primary care electronic health records, to show that genetic phase influences lifetime risk of disease across 20 gene-trait combinations (FDR < 5%). Using a permutation approach, we find evidence for genetic phase contributing to disease susceptibility for a collection of gene-trait pairs, including FLG-asthma () and USH2A-visual impairment (). Taken together, we demonstrate the utility of phasing large-scale genetic sequencing cohorts for robust identification of the phenome-wide consequences of compound heterozygosity.

Preprint↗

Plasma-controlled nanocrystallinity and phase composition of TiO2: a smart way to enhance biomimetic response.

This contribution sheds light on the role of crystal size and phase composition in inducing biomimetic apatite growth on the surface of nanostructured titania films synthesized by reactive magnetron sputtering of Ti targets in Ar+O(2) plasmas. Unlike most existing techniques, this method enables one to deposit highly crystalline titania films with a wide range of phase composition and nanocrystal size, without any substrate heating or postannealing. Moreover, by using this dry plasma-based method one can avoid surface hydroxylation at the deposition stage, almost inevitable in wet chemical processes. Results of this work show that high phase purity and optimum crystal size appear to be the essential requirement for efficient apatite formation on magnetron plasma-fabricated bioactive titania coatings.

Apatites↗

Polymorphisms in the mannose binding lectin-2 gene and acute respiratory distress syndrome.

OBJECTIVE: The variant alleles in the mannose binding lectin-2 (MBL-2) gene have been associated with MBL deficiency and increased susceptibility to sepsis. We postulate that the variant MBL-2 genotypes are associated with increased susceptibility to and mortality in acute respiratory distress syndrome (ARDS). DESIGN: Nested case-control study. SETTING: Tertiary academic medical center. PATIENTS: Two hundred and twelve Caucasians with ARDS and 442 controls genotyped for the variant X, D, B, and C alleles of codon -221, 52, 54, and 57, respectively. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients homozygous for the variant codon 54B allele (54BB) had worse severity of illness on admission (p = .007), greater likelihood of septic shock (p = .04), and increased odds of ARDS (adjusted odds ratio, 6.7; 95% confidence interval, 1.5-31) when compared with heterozygotes and homozygotes for the wild-type allele. This association with ARDS was especially strong among the 311 patients with septic shock (adjusted odds ratio, 12.0; 95% confidence interval, 1.9-74). Among the patients with ARDS, the 54BB genotype was associated with more daily organ dysfunction (p = .01) and higher mortality (adjusted hazard rate, 4.0; 95% confidence interval, 1.6-10). Development of ARDS and outcomes in ARDS did not vary significantly with variant alleles of codon -221, 52, and 57, but the power to detect an effect was limited secondary to the low allele frequencies. CONCLUSIONS: The MBL-2 codon 54BB genotype may be important in ARDS susceptibility and outcome. Additional studies are needed to confirm these findings in other populations.

Adolescent↗

Role of glutamate in the rostral ventrolateral medulla in acupuncture-related modulation of visceral reflex sympathoexcitation.

Visceral sympathoexcitatory reflexes induced by stimulation of the gallbladder with bradykinin (BK) are attenuated by electroacupuncture (EA) at Neiguan-Jianshi (P5-6) acupoints located over the median nerve. Previous studies have shown that neurons in the rostral ventrolateral medulla (rVLM) receive convergent input from visceral organs and somatic nerves (activated by EA). Glutamate (Glu), an important excitatory neurotransmitter in the rVLM, processes visceral sympathoexcitatory cardiovascular reflexes. In the present study, we determined the relation between EA-mediated opioidergic modulation of visceral cardiovascular responses and Glu. Reflex cardiovascular responses were evoked by application of BK to the gallbladder before and after EA in anesthetized cats. Glu concentrations ([Glu]) were measured by HPLC from samples collected by microdialysis probe(s) inserted unilaterally or bilaterally into the rVLM. BK-induced reflex responses and [Glu] were attenuated by 45% and 70%, respectively, after 30 min of EA (n = 6). EA alone did not change [Glu] in the rVLM (n = 6, P > 0.05). However, microdialysis of naloxone (100 mM) into the rVLM reversed EA-related inhibition of blood pressure and [Glu] (n = 5). Immunohistochemical visualization showed that delta-opioid receptors colocalized with, and were in close apposition to, vesicular Glu transporter 3- and c-Fos-double-labeled perikarya and processes of rVLM neurons after gallbladder stimulation with BK. These data suggest that EA attenuates BK-induced visceral sympathoexcitatory reflexes through opioid-mediated inhibition of Glu's action in the rVLM.

Acupuncture↗

The microtubule plus-end tracking protein EB1 is required for Kv1 voltage-gated K+ channel axonal targeting.

Axonal Kv1 channels regulate action potential propagation-an evolutionarily conserved function important for the control of motor behavior as evidenced from the linkage of human Kv1 channel mutations to myokymia/episodic ataxia type 1 (EA1) and the Shaker mutant phenotype in Drosophila. To search for the machinery that mediates axonal targeting of Kv1 channels composed of both alpha and beta subunits, we first demonstrate that Kvbeta2 is responsible for targeting Kv1 channels to the axon. Next, we show that Kvbeta2 axonal targeting depends on its ability to associate with the microtubule (MT) plus-end tracking protein (+TIP) EB1. Not only do Kvbeta2 and EB1 move in unison down the axon, Brefeldin A-sensitive Kv1-containing vesicles can also be found at microtubule ends near the cell membrane. In addition, we found that Kvbeta2 associates with KIF3/kinesin II as well. Indeed, Kv1 channels rely on both KIF3/kinesin II and EB1 for their axonal targeting.

Animals↗

PtRu nanoparticle electrocatalyst with bulk alloy properties prepared through a sonochemical method.

Properties of PtRu nanoparticles prepared using high-intensity sonochemistry are reported. Syntheses were carried out in tetrahydrofuran (THF) containing Ru3+ and Pt4+ in a fixed mole ratio of either 1:10 or 1:1. X-ray diffraction measurements confirmed sonocation produces an alloy phase and showed that the composition of the nanometer scale metal particles is close to the mole fraction of Ru3+ and Pt4+ in solution with deviations that tend toward Ru enrichment in the alloy phase. The materials gave responses that are similar in terms of peak potential and current density, referenced to the catalyst active surface area, to those of bulk alloys in voltammetry experiments involving CO stripping and CH3OH electrochemical oxidation in 0.1 M H2SO4. The results show that sonochemical methods have the potential to produce nanometer scale bimetallic electrocatalysts that possess alloy properties. The materials have application in mechanistic studies of fuel cell reactions and as platforms for the development of CO tolerant fuel cell catalyst.

Journal Article↗

Second hand smoke exposure and survival in early-stage non-small-cell lung cancer patients.

PURPOSE: Second hand smoke (SHS) exposure is associated with higher risk of lung cancer. However, the role of SHS in lung cancer survival is not clear. EXPERIMENTAL DESIGN: We examined the association between self-reported SHS exposure before diagnosis and overall survival and recurrence-free survival in 393 early-stage non-small-cell lung cancer patients. SHS exposure was analyzed by both duration and location of exposure using log-rank test and Cox proportional hazard models, adjusting for covariates including pack-years of smoking. RESULTS: The median follow-up time was 66 months (range, 0.2-140 months). There were 135 recurrences and 213 deaths. The 5-year overall survival rates were 71% [95% confidence interval (95% CI), 62-81%], 61% (51-72%), 49% (38-60%), and 47% (37-58%), respectively, for patients with the lowest to highest quartile of SHS exposure durations (P < 0.001, log-rank test), with the adjusted hazard ratio (AHR) of 1.57 (95% CI, 1.02-2.41) for the highest versus lowest quartile of SHS exposure durations (P(trend) = 0.04). For different SHS exposure locations, a stronger association was found for SHS exposure at work (AHR of the highest versus lowest quartile, 1.71; 95% CI, 1.12-2.61; P(trend) = 0.03) than for exposure at home (AHR, 1.26; 95% CI, 0.86-1.86; P(trend) = 0.20) or leisure places (AHR, 1.28; 95% CI, 0.83-1.95; P(trend) = 0.16). Similar associations were observed when SHS exposure durations were dichotomized into two or three groups and between SHS exposure and recurrence-free survival. CONCLUSIONS: SHS exposure is associated with worse survival in early-stage non-small-cell lung cancer patients, especially for SHS exposure at the work.

Adult↗

Medium optimization by combination of response surface methodology and desirability function: an application in glutamine production.

An optimization strategy based on desirability function approach (DFA) together with response surface methodology (RSM) has been used to optimize production medium in L-glutamine fermentation. Fermentation problems often force to reach a compromise between different experimental variables in order to achieve the most suitable strategy applying in industrial production. The importance of the use of multi-objective optimization methods lies in the ability to cope with this kind of problems. A sequential RSM with different combinations of glucose and (NH(4))(2)SO(4) was performed to attain the optimal medium (OM-1) in glutamine production. Based on the result of RSM and the evaluation of production cost, a more economical optimal medium (OM-2) was obtained with the aid of DFA. In DFA study, glutamate, the main by-product in glutamine fermentation as another response was considered. Compared with OM-1 in validated experiment, similar amounts of glutamine were obtained in OM-2 while the concentration of glutamate and the production cost decreased by 53.6 and 7.1%, respectively.

Biotechnology↗

Identification and two-photon imaging of oligodendrocyte in CA1 region of hippocampal slices.

Oligodendrocyte (OL) plays a critical role in myelination and axon maintenance in central nervous system. Recent studies show that OL can also express NMDA receptors in development and pathological situations in white matter. There is still lack of studies about OL properties and function in gray matter of brain. Here we reported that some glial cells in CA1 region of rat hippocampal slices (P15-23) had distinct electrophysiological characteristics from the other glia cells in this region, while they displayed uniform properties with OL from white matter in previous report; therefore, they were considered as OL in hippocampus. By loading dye in recording pipette and imaging with two-photon laser scanning microscopy, we acquired the high spatial resolution, three-dimension images of these special cells in live slices. The OL in hippocampus shows a complex process-bearing shape and the distribution of several processes is parallel to Schaffer fiber in CA1 region. When stimulating Schaffer fiber, OL displays a long duration depolarization mediated by inward rectifier potassium channel. This suggested that the OL in CA1 region could sense the neuronal activity and contribute to potassium clearance.

Action Potentials↗

Promoter hypermethylation-mediated down-regulation of LATS1 and LATS2 in human astrocytoma.

LATS1 and LATS2 are tumor suppressor genes implicated in the regulation of cell cycle, but their methylation statuses are still unknown in human astrocytoma. Here, we found that the promoter hypermethylation frequencies of LATS1 and LATS1 were 63.66% (56/88) and 71.5% (63/88) in 88 astrocytomas by methylation-specific PCR. But no methylation of LATS1 and LATS2 promoter was detected in the 10 normal brain tissues. There was an increased methylation frequency of LATS1 and LATS2 with the malignant development of astrcytoma. By real-time PCR, the mRNA expression of LATS1 or LATS2 was detected significantly decreased in different pathological grade astrocytomas (P<0.05). And the mRNA levels of LATS1 and LATS2 in astrocytomas with hypermethylation were both significantly (P<0.01) lower than those without methylation. The methylation of LATS1 and LATS2 was detected in U251 and SHG-44 cell lines, and 5-aza-deoxycytidine could restore their expression to induce cell apoptosis. Our results suggested that LATS1 and LATS2 mRNA was down-regulated in astrocytoma by hypermethylation of the promoter. The methylation and mRNA expression of LATS1 and LATS2 may provide useful clues to the development of the diagnostic assays for astrocytoma. Our results also suggested that LATS1 and LATS2 may be a useful target for astrocytoma therapy.

Adult↗

Expression analyses of 27 DNA repair genes in astrocytoma by TaqMan low-density array.

DNA repair systems act to maintain genome integrity in the face of replication errors, environmental insults, and the cumulative effects of age. The mRNA expressions of 27 genes of the DNA repair system as well as their correlation with the clinical characteristics were studied in human astrocytoma. We applied TaqMan low-density array to investigate the mRNA expressions of 27 DNA repair genes in 40 astrocytoma tissues (10 of grade II, 10 of grade III, and 20 of grade IV, according to the WHO Grading System). And the normal brain tissues from 10 non-astrocytoma patients were collected as the control. In addition, correlation of their mRNA levels with clinical characteristics was also analyzed. We found that the expression of the 13 genes were significantly (P<0.01) down-regulated in grade II, III, IV of astrocytoma compared to normal brain tissues, including ERCC1, ERCC2, ERCC3, ERCC4, MGMT, MLH1, MLH3, NTHL1, OGG1, RAD50, SMUG1, XRCC4 and XRCC5. Meanwhile, we found that the expression of MSH2, MSH6, NUDT1 and XRCC3 were only significantly lower in grade II and III of astrocytoma, and the expression of MRE11A and MUS81 were only significantly lower in grade III and IV. But the expression of MPG, MSH3, MUTHY and RAD51 were not changed in any grade of astrocytoma. Furthermore, we found that the decrease expression of eight genes was significantly (P<0.05) associated with a poor prognosis, including ERCC3, ERCC4, MLH3, MRE11A, NTHL1, RAD50, XRCC4 and XRCC5. We suggest that TaqMan low-density array is an effective multivariate technique to examine the expression of DNA repair genes in astrocytomas, which can be applied to identify tumor-specific genes. We also suggest that the down-regulation of some DNA repair genes may be associated with pathogenesis and poor prognosis of astrocytoma.

Adolescent↗

Synthesis and immunobiological activity of an original series of acyclic lipid a mimics based on a pseudodipeptide backbone.

Ndelta-L-Homoserinyl-D-ornithinol pseudodipeptides N-acylated with typical Escherichia coli lipid A fatty acid residues and mono-O- or bis-O-phosphorylated have been prepared and their properties investigated. The derivatives carrying two phosphate groups were found to be inducers of NO production. In addition, while they were unable to induce significantly the production of interleukin-6 (IL-6) by human PBMC cells, these compounds behaved also as potent antagonists of LPS-induced IL-6 production in the same human cells system. In conclusion, the molecules described here are the first members of an original class of immunobiologically active lipid A mimics based on an acyclic pseudodipeptide backbone carrying only the essential functionalities of the parent lipid A structure (OM-174). As the products exhibit very low endotoxicity and pyrogenicity, this class of lipid A mimics therefore opens a new generation of immunoadjuvants that possibly could reach clinical applications.

Adjuvants, Immunologic↗

Getting more from digital SNP data.

The digital SNP method has been proposed for identifying loss of heterozygosity (LOH) in tumour tissue and correlating it with patients' clinical characteristics. The method evaluates a tumour's allelic count at a single nucleotide polymorphism (SNP) for which the patient's normal tissue is heterozygous. The count is used to classify the tumour as positive or negative for LOH, using the sequential probability ratio test (SPRT). However, the SPRT was not developed for analysing digital SNP experiments. When applied to digital SNP data, the SPRT has several anomalies that can result in both loss of data and tumour misclassification. The anomalies are caused by discrepancies between the design of digital SNP experiments and the setting for which SPRT was developed. We propose an alternative classification scheme based on the false discovery rate, and show that it outperforms the SPRT when applied to Digital SNP data.

Allelic Imbalance↗

ADAM: another database of abbreviations in MEDLINE.

MOTIVATION: Abbreviations are an important type of terminology in the biomedical domain. Although several groups have already created databases of biomedical abbreviations, these are either not public, or are not comprehensive, or focus exclusively on acronym-type abbreviations. We have created another abbreviation database, ADAM, which covers commonly used abbreviations and their definitions (or long-forms) within MEDLINE titles and abstracts, including both acronym and non-acronym abbreviations. RESULTS: A model of recognizing abbreviations and their long-forms from titles and abstracts of MEDLINE (2006 baseline) was employed. After grouping morphological variants, 59 405 abbreviation/long-form pairs were identified. ADAM shows high precision (97.4%) and includes most of the frequently used abbreviations contained in the Unified Medical Language System (UMLS) Lexicon and the Stanford Abbreviation Database. Conversely, one-third of abbreviations in ADAM are novel insofar as they are not included in either database. About 19% of the novel abbreviations are non-acronym-type and these cover at least seven different types of short-form/long-form pairs. AVAILABILITY: A free, public query interface to ADAM is available at http://arrowsmith.psych.uic.edu, and the entire database can be downloaded as a text file.

Animals↗