Biomedical subjects

Wei Wang

Publications and source records attributed to Wei Wang.

At least 55 records · Page 3Linked to original sources

PubMed2025

Exploring the causal role of plasma metabolites in pediatric asthma: a Mendelian randomization study.

BACKGROUND: Pediatric asthma (PA) is the prevailing chronic respiratory ailment in childhood. A better understanding of plasma metabolites is the goal for elucidating the molecular pathological mechanisms of PA and investigating novel therapeutic approaches. METHODS: Data for PA from Genome-Wide Association Studies (GWAS) was derived from the IEU-OpenGWAS project, featuring a collection of 1400 plasma metabolites. The inverse-variance weighting (IVW) method assessed causal relationships between plasma metabolites and PA, with measures taken to mitigate horizontal pleiotropy and heterogeneity. To select instrumental variables, a genome-wide significance threshold (p < 5 × 10-8) was applied to ensure robust genetic instruments. A Bonferroni correction controlled for multiple testing, with statistical significance defined as p < 3.57 × 10-5) (0.05/1400). To further substantiate outcomes, a reverse Mendelian randomization analysis was conducted. RESULTS: Research found 91 plasma metabolites linked to PA, ten of which showed significant associations. Of note, 20:4n6 levels (IVW: OR (95% CI) = 1.062 (1.030 to 1.094) and G/C16 (IVW: OR (95% CI) = 0.886 (0.832 to 0.943) were identified as pivotal exposure factors for PA. CONCLUSIONS: This study highlights 10 plasma metabolites that may have significant associations with PA incidence, with 20:4n6 levels and G/C16 potentially serving as valuable biomarkers for the early detection and management of PA.

Humans↗

PubMed2025

Tumors hijack macrophages for iron supply to promote bone metastasis and anemia.

Bone marrow is both a primary site for hematopoiesis and a fertile niche for metastasis. The mechanism of the common occurrence of anemia among patients with bone metastasis remains poorly understood. Here, we show that a specialized population of VCAM1+CD163+CCR3+ macrophages, normally essential for erythropoiesis by transporting iron to erythroblasts, are highly enriched in the bone metastatic niche in mouse models. Tumor cells hijack these macrophages for iron supply, reducing iron availability for erythroblasts, impairing erythropoiesis, and contributing to anemia. Increased iron supply enables tumor cells to produce hemoglobin in response to hypoxia, mimicking erythroblasts. We identify macrophages with similar iron-transporting features in human bone metastases and show that elevated HBB expression correlates with increased risk of bone metastasis. These findings establish iron-transporting macrophages as an essential component of the metastatic bone niche, revealing a critical interplay between immune cells, metal metabolism, and tumor cell plasticity in driving metastasis and anemia.

Animals↗

PubMed2025

Endogenous fine-mapping and prioritization of functional regulatory elements in complex genetic loci.

Most genetic loci linked to polygenic traits are in non-coding regions, with complex regulation and linkage disequilibrium (LD), complicating causal variant and gene prioritization. We used multiplexed single-cell CRISPR interference and activation perturbations to investigate cis-regulatory element (CRE) and gene expression relationships within tight LD in the endogenous chromatin context. We demonstrated the prevalence of multiple causality in perfect LD (pLD) for independent expression quantitative trait loci (eQTLs) and uncovered fine-grained genetic effects on gene expression within pLD, which are difficult to decipher using traditional eQTL fine-mapping or existing computational methods. We found that over one-third of the causal CREs lack classical epigenetic markers prior to perturbation, and we functionally validated one of these hidden regulatory mechanisms. Leveraging Multiome single-cell epigenetic and sequence perturbations, we highlighted the regulatory plasticity of the human genome. Our study will guide the exploration of missing causal mechanisms underlying molecular trait regulation and disease development.

Humans↗

PubMed2025

LncRNA Profiling and ceRNA Network Construction of Intrauterine Exosomes in Goats During Embryo Implantation.

Exosomes have been shown to play an important role in embryo implantation, but the mechanism is still unclear. This study aimed to investigate the functional roles of lncRNAs in intrauterine exosomes in goat pregnancy. We used RNA-seq to identify the lncRNA profiles of exosomes obtained from goat uterine rinsing fluid at 5, 15, and 18 days of gestation. In addition, we performed weighted gene co-expression network analysis based on differentially expressed mRNAs (DEMs) and lncRNAs (DELs). Functional enrichment analyses of gene modules were conducted using Gene Ontology classification (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. A lncRNA-miRNA-mRNA competing endogenous RNA (ceRNA) regulatory network was constructed based on predictive interaction derived from miRTarBase, miRDB and RNAhybrid databases. Altogether, 831 DELs were identified. GO and KEGG analysis showed that the target genes were enriched in processes associated with embryo implantation, such as signaling receptor activity, binding and immune response. Nine functional co-expression modules were enriched in various biological processes, such as metabolic pathways, protein transport, cell cycle and VEGF signaling pathway. Additionally, 12 lncRNA-mediated ceRNA networks were constructed. Our results demonstrate that exosomal lncRNAs in uterine flushing fluid exhibit dynamic changes across gestational stages and play an important role in regulating the uterine microenvironment during embryo implantation. These findings provide a foundational basis for screening exosome-derived lncRNAs that influence embryo implantation and contribute to elucidating the mechanistic roles of lncRNAs in exosome-mediated processes during early pregnancy.

embryo implantation↗

PubMed2025

ChemPerturb-seq screen identifies a small molecule cocktail enhancing human beta cell survival after subcutaneous transplantation.

Traditional chemical screens have focused on a single assay per screen, making them labor intensive and costly. Here, we combined a chemical screen with single-cell RNA sequencing (scRNA-seq) to perform Chemical Perturb-seq (ChemPerturb-seq), enabling a systematic analysis of the molecular changes of human beta cells upon individual small molecule treatments. Using this platform, we performed an in vivo barcoded screen and discovered a small molecule cocktail, including beta-lipotropin 61-91, insulin growth factor-1, and prostaglandin E2, with which preconditioning human beta cells and primary islets significantly enhanced function and survival when transplanted subcutaneously to female, but not to male, mice. We identified two additional molecules, serotonin and histamine, that promote islet function when transplanted subcutaneously to male mice using ChemPerturb-seq. Such small molecule cocktails could be applied to improve the current FDA-approved islet transplantation procedure. Finally, we developed an artificial intelligence (AI)-powered website, ChemPerturbDB, which provides user-friendly open access analysis of the extensive ChemPerturb-seq dataset.

Humans↗

PubMed2025

ALDOC and PGK1 coordinately induce glucose metabolism reprogramming and promote development of colorectal cancer.

Colorectal cancer (CRC) remains a significant health challenge globally, demanding a comprehensive understanding of its molecular underpinnings for effective management. In this study, we investigated the role of Aldolase C (ALDOC), a glycolytic enzyme, in CRC pathogenesis. Transcriptomic analysis of CRC tissues from The Cancer Genome Atlas (TCGA) revealed a substantial upregulation of ALDOC, correlating with adverse clinical outcomes. Immunohistochemical (IHC) staining of locally collected patient-derived tissues corroborated these findings, demonstrating elevated ALDOC expression in tumor tissues, particularly in advanced stages. Functional studies elucidated the regulatory role of ALDOC in CRC cell phenotypes. ALDOC knockdown significantly inhibited cell proliferation, induced apoptosis, arrested cell cycle progression, and suppressed cell migration in vitro. Moreover, in vivo studies using xenograft models confirmed that ALDOC knockdown attenuated tumor growth. Mechanistically, ALDOC was found to interact with hypoxia-inducible factor 1 alpha (HIF1A) and enhance its transcriptional activity on phosphoglycerate kinase 1 (PGK1), a key glycolytic enzyme. Dual-luciferase reporter assays and chromatin immunoprecipitation experiments validated the ALDOC-mediated transcriptional activation of PGK1. Further functional rescue experiments revealed a synergistic interplay between ALDOC and PGK1 in regulating CRC cell phenotypes. Additionally, ALDOC was implicated in promoting aerobic glycolysis in CRC cells, potentially through PGK1 regulation. Collectively, our findings unveil ALDOC as a critical regulator of CRC pathogenesis, offering insights into its potential as a therapeutic target and highlighting the ALDOC/PGK1 axis as a promising avenue for further investigation in CRC.

Humans↗

PubMed2025

Intraocular pressure is a promising target for myopia control.

BACKGROUND: Myopia presents a noteworthy global health concern, urging exploration of innovative treatments. The role of intraocular pressure (IOP) in regulating the progression of myopia has been controversial. METHODS: To investigate the impact of reducing IOP to varying extents on myopia progression, three groups receiving distinct IOP-lowering medications (Brinzolamide, Latanoprost, and a combination of Brinzolamide and Latanoprost) were designed in a form-deprived myopic guinea pig model. Additionally, proteomics analyses were conducted to identify differentially expressed proteins in the sclera. RESULTS: Based on 24-h and 4-week IOP monitoring, the group receiving both Brinzolamide and Latanoprost exhibited the greatest magnitude of IOP reduction and the most significant inhibition of axial length (AL) growth. Moreover, the administration of IOP-lowering medications increased choroidal thickness and induced alterations in the structure of scleral collagen fibrils. Notably, scleral proteomics revealed remodeling processes associated with key mechanisms, including proteolysis, fibrinolysis, and metal ion binding. CONCLUSIONS: Our findings highlight that pressure-dependent scleral remodeling contributes to the deceleration of AL elongation. These results underscore the efficacy of IOP reduction in mitigating the progression of myopia, providing a promising alternative strategy for myopia management.

Myopia↗

PubMed2025

Antiviral Activity of the MEK1/2 Inhibitor Trametinib Against Lymphocytic Choriomeningitis Virus.

The lymphocytic choriomeningitis virus (LCMV) is a widespread pathogen that causes mild-to-severe infections to severe outcomes. In this study, we explored the potential of trametinib, a mitogen-activated protein kinase (MAPK) inhibitor, as an antiviral agent against LCMV. Trametinib demonstrated significant antiviral activity against two distinct LCMV strains, Armstrong and Cl13, with promising half-maximal inhibitory concentrations (IC50) and selectivity indices (SI) indicating its potency and safety profile. Mechanistic investigations revealed that trametinib interfered with multiple stages of the LCMV life cycle, including membrane fusion and genomic replication, leading to the robust inhibition of viral proliferation. Furthermore, trametinib disrupted the MEK/ERK signaling pathway, which is crucial for LCMV infection. In both in vitro and in vivo experiments, trametinib effectively reduced viral loads and mitigated pathological damage to the spleen and liver tissues. Overall, our findings suggest that trametinib is a promising novel therapeutic option for combating LCMV infection by targeting key stages of the viral life cycle and disrupting host cellular signaling pathways. Further exploration of the antiviral properties of trametinib is likely to pave the way for its clinical development as a treatment for LCMV infections.

Pyridones↗

PubMed2025

Bergamottin, A Natural Bioactive Compound, Inhibits Dabie Bandavirus Infection In Vitro and In Vivo.

Severe fever with thrombocytopenia syndrome (SFTS) is a novel, highly fatal disease caused by Dabie bandavirus (DBV), also referred to as severe fever with thrombocytopenia syndrome virus (SFTSV). DBV is endemic to many Asian countries, and its incidence has recently increased. However, there are currently no specific therapies for combating DBV infection. Here we verified whether the natural bioactive compound, bergamottin, effectively inhibits DBV in vitro and in vivo. A primary in vitro study suggested that bergamottin suppressed DBV infection both in Vero E6 and Huh-7 cells in a dose-dependent manner. Time-of-addition assay revealed that bergamottin interferes with DBV infection at multiple stages of the viral life cycle. Moreover, bergamottin inhibits viral internalization and effectively reduces viral genome replication. The efficacy of bergamottin at doses of 75 and 120 mg/kg/d against DBV infection in an IFNAR-/- mouse infection model was investigated. Oral delivery at a dose of 120 mg/kg/d significantly reduced the number of the viral RNA copies in the kidneys, spleen, and lungs. These findings highlight that bergamottin is a promising agent that could be further developed as a therapeutic agent against DBV infection.

Animals↗

PubMed2025

CRISPR-Cas9-mediated knockout of OsKCS11 in rice reveals potential crosstalk between very-long-chain fatty acids and cytokinin.

Very-long-chain fatty acids (VLCFAs) play crucial roles in various physiological processes in plants. Through our investigation using a CRISPR-Cas9 knockout mutant library in rice, we identified a semi-dwarf rice mutant named CRISPR-Cas-based dwarf-1 (csd-1). This mutant displayed multiple developmental defects, such as decreased plant height, panicle length, seed size, and seed-setting rate. Whole-genome resequencing analysis revealed that a T-nucleotide insertion in β-ketoacyl-CoA synthase 11 (KCS11), responsible for the initial step in fatty acid elongation, was responsible for the observed defects in csd-1. The identity of csd-1 was confirmed through genetic complementation and CRISPR-Cas9-mediated knockout. Expression analysis indicated that OsKCS11 was present in various tissues, with differential abundance observed through RT-qPCR and promoter GUS staining, and strong localization at the node position by RNA in situ hybridization; furthermore, OsKCS11 protein was confirmed to be in the endoplasmic reticulum. Furthermore, csd-1 exhibited significantly reduced levels of linolenic acid (18:3), C24:0-OH, C28:0-alkanes, C29:0-alkanes, alpha-tocopherol, and C33:0-alkanes, while trans-nonadecenoic acid and behenic acid levels were increased. Cytokinin analysis revealed significant increases in isopentenyladenine (IPA) and cis-zeatin (cZ) levels in csd-1. Molecular investigations indicated upregulation of genes involved in cytokinin biosynthesis or signaling, suggesting a potential link between VLCFAs and cytokinin synthesis through acetyl-CoA. This study not only proposed an alternative gene mapping method based on whole-genome resequencing but also elucidated the mechanism by which VLCFAs influence cytokinin synthesis and signaling.

Oryza↗

PubMed2024

Acute MeCP2 loss in adult mice reveals transcriptional and chromatin changes that precede neurological dysfunction and inform pathogenesis.

Mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene cause Rett syndrome, a severe childhood neurological disorder. MeCP2 is a well-established transcriptional repressor, yet upon its loss, hundreds of genes are dysregulated in both directions. To understand what drives such dysregulation, we deleted Mecp2 in adult mice, circumventing developmental contributions and secondary pathogenesis. We performed time series transcriptional, chromatin, and phenotypic analyses of the hippocampus to determine the immediate consequences of MeCP2 loss and the cascade of pathogenesis. We find that loss of MeCP2 causes immediate and bidirectional progressive dysregulation of the transcriptome. To understand what drives gene downregulation, we profiled genome-wide histone modifications and found that a decrease in histone H3 acetylation (ac) at downregulated genes is among the earliest molecular changes occurring well before any measurable deficiencies in electrophysiology and neurological function. These data reveal a molecular cascade that drives disease independent of any developmental contributions or secondary pathogenesis.

Animals↗

PubMed2024

Inhibiting the expression of spindle appendix cooled coil protein 1 can suppress tumor cell growth and metastasis and is associated with cancer immune cells in esophageal squamous cell carcinoma.

Inhibiting the expression of spindle appendix cooled coil protein 1 (SPDL1) can slow down disease progression and is related to poor prognosis in patients with esophageal cancer. However, the specific roles and molecular mechanisms of SPDL1 in esophageal squamous cell carcinoma (ESCC) have not been explored yet. The current study aimed to investigate the expression levels of SPDL1 in ESCC via transcriptome analysis using data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus databases. Moreover, the biological roles, molecular mechanisms, and protein networks involved in SPDL1 were identified using machine learning and bioinformatics. The cell counting kit-8 assay, EdU staining, and transwell assay were used to investigate the effects of inhibiting SPDL1 expression on ESCC cell proliferation, migration, and invasion. Finally, the correlation between the SPDL1 expression and cancer immune infiltrating cells was evaluated by analyzing data from the TCGA database. Results showed that SPDL1 was overexpressed in the ESCC tissues. The SPDL1 expression was related to age in patients with ESCC. The SPDL1 co-expressed genes included those involved in cell division, cell cycle, DNA repair and replication, cell aging, and other processes. The high-risk scores of SPDL1-related long non-coding RNAs were significantly correlated with overall survival and cancer progression in patients with ESCC (P < 0.05). Inhibiting the SPDL1 expression was effective in suppressing the proliferation, migration, and invasion of ESCC TE-1 cells (P < 0.05). The overexpression of SPDL1 was positively correlated with the levels of Th2 and T-helper cells, and was negatively correlated with the levels of plasmacytoid dendritic cells and mast cells. In conclusion, SPDL1 was overexpressed in ESCC and was associated with immune cells. Further, inhibiting the SPDL1 expression could effectively slow down cancer cell growth and migration. SPDL1 is a promising biomarker for treating patients with ESCC.

Humans↗

PubMed2024

Identification of key immune-related genes and potential therapeutic drugs in diabetic nephropathy based on machine learning algorithms.

BACKGROUND: Diabetic nephropathy (DN) is a major contributor to chronic kidney disease. This study aims to identify immune biomarkers and potential therapeutic drugs in DN. METHODS: We analyzed two DN microarray datasets (GSE96804 and GSE30528) for differentially expressed genes (DEGs) using the Limma package, overlapping them with immune-related genes from ImmPort and InnateDB. LASSO regression, SVM-RFE, and random forest analysis identified four hub genes (EGF, PLTP, RGS2, PTGDS) as proficient predictors of DN. The model achieved an AUC of 0.995 and was validated on GSE142025. Single-cell RNA data (GSE183276) revealed increased hub gene expression in epithelial cells. CIBERSORT analysis showed differences in immune cell proportions between DN patients and controls, with the hub genes correlating positively with neutrophil infiltration. Molecular docking identified potential drugs: cysteamine, eltrombopag, and DMSO. And qPCR and western blot assays were used to confirm the expressions of the four hub genes. RESULTS: Analysis found 95 and 88 distinctively expressed immune genes in the two DN datasets, with 14 consistently differentially expressed immune-related genes. After machine learning algorithms, EGF, PLTP, RGS2, PTGDS were identified as the immune-related hub genes associated with DN. In addition, the mRNA and protein levels of them were obviously elevated in HK-2 cells treated with glucose for 24 h, as well as their mRNA expressions in kidney tissues of mice with DN. CONCLUSION: This study identified 4 hub immune-related genes (EGF, PLTP, RGS2, PTGDS), as well as their expression profiles and the correlation with immune cell infiltration in DN.

Diabetic Nephropathies↗

PubMed2024

Multiple sclerosis and abnormal spermatozoa: A bidirectional two-sample mendelian randomization study.

OBJECTIVE: Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, and previous observational epidemiological studies have suggested an association between MS and male infertility; male infertility due to sperm abnormalities may result from a number of aetiological factors, such as genetics, autoimmune factors, etc., and there are currently no studies to assess whether MS is associated with sperm abnormalities in men. Therefore, we performed a Mendelian randomization (MR) analysis to assess the causal relationship between MS and abnormal spermatozoa. METHODS: In this study, independent single nucleotide polymorphisms (SNPs) strongly associated with multiple sclerosis (MS) were identified by mining public genome-wide association study repositories and used as instrumental variables to explore causality. The causal effect of MS on sperm abnormalities was systematically assessed using two-sample Mendelian randomization (MR) techniques, and various analytical models such as inverse variance weighting (IVW), MR-Egger and MR-PRESSO were implemented to dissect the association. In addition, a wide range of sensitivity tests, including Cochran's Q test to detect heterogeneity, MR-Egger intercept analysis to assess bias, leave-one-out to test model robustness, and funnel plot analysis to detect potential publication bias, were implemented to ensure the robustness and reliability of the causal inference results. RESULTS: There was a significant causal relationship between MS and abnormal sperm (OR 1.090, 95% CI [1.017-1.168], p = 0.014); The accuracy and robustness of the results were confirmed by sensitivity analysis. CONCLUSION: Here we show that there appears to be a causal relationship between multiple sclerosis and abnormal spermatozoa. MS as a chronic disease has a higher risk of concomitant sperm abnormalities in its male patients, and reproductive and fertility issues in men with MS should receive special attention from clinicians.

Humans↗

PubMed2024

Sulfonamide-induced DNA hypomethylation disturbed sugar metabolism in rice (Oryza sativa L.).

DNA methylation is well-accepted as a bridge to unravel the complex interplay between genome and environmental exposures, and its alteration regulated the cellular metabolic responses towards pollutants. However, the mechanism underlying site-specific aberrant DNA methylation and metabolic disorders under pollutant stresses remained elusive. Herein, the multilevel omics interferences of sulfonamides (i.e., sulfadiazine and sulfamerazine), a group of antibiotics pervasive in farmland soils, towards rice in 14 days of 1 mg/L hydroponic exposure were systematically evaluated. Metabolome and transcriptome analyses showed that 57.1-71.4 % of mono- and disaccharides were accumulated, and the differentially expressed genes were involved in the promotion of sugar hydrolysis, as well as the detoxification of sulfonamides. Most differentially methylated regions (DMRs) were hypomethylated ones (accounting for 87-95 %), and 92 % of which were located in the CHH context (H = A, C, or T base). KEGG enrichment analysis revealed that CHH-DMRs in the promoter regions were enriched in sugar metabolism. To reveal the significant hypomethylation of CHH, multi-spectroscopic and thermodynamic approaches, combined with molecular simulation were conducted to investigate the molecular interaction between sulfonamides and DNA in different sequence contexts, and the result demonstrated that sulfonamides would insert into the minor grooves of DNA, and exhibited a stronger affinity with the CHH contexts of DNA compared to CG or CHG contexts. Computational modeling of DNA 3D structures further confirmed that the binding led to a pitch increase of 0.1 Å and a 3.8° decrease in the twist angle of DNA in the CHH context. This specific interaction and the downregulation of methyltransferase CMT2 (log2FC = -4.04) inhibited the DNA methylation. These results indicated that DNA methylation-based assessment was useful for metabolic toxicity prediction and health risk assessment.

DNA Methylation↗

PubMed2007

Experimental validation of novel genes predicted in the un-annotated regions of the Arabidopsis genome.

BACKGROUND: Several lines of evidence support the existence of novel genes and other transcribed units which have not yet been annotated in the Arabidopsis genome. Two gene prediction programs which make use of comparative genomic analysis, Twinscan and EuGene, have recently been deployed on the Arabidopsis genome. The ability of these programs to make use of sequence data from other species has allowed both Twinscan and EuGene to predict over 1000 genes that are intergenic with respect to the most recent annotation release. A high throughput RACE pipeline was utilized in an attempt to verify the structure and expression of these novel genes. RESULTS: 1,071 un-annotated loci were targeted by RACE, and full length sequence coverage was obtained for 35% of the targeted genes. We have verified the structure and expression of 378 genes that were not present within the most recent release of the Arabidopsis genome annotation. These 378 genes represent a structurally diverse set of transcripts and encode a functionally diverse set of proteins. CONCLUSION: We have investigated the accuracy of the Twinscan and EuGene gene prediction programs and found them to be reliable predictors of gene structure in Arabidopsis. Several hundred previously un-annotated genes were validated by this work. Based upon this information derived from these efforts it is likely that the Arabidopsis genome annotation continues to overlook several hundred protein coding genes.

Arabidopsis↗

PubMed2007

The selective retention of lutein, meso-zeaxanthin and zeaxanthin in the retina of chicks fed a xanthophyll-free diet.

Lutein and zeaxanthin are pigmented oxygenated carotenoids, or xanthophylls, derived from plants and concentrated in the retina of primates and birds. We investigated the transport, distribution and depletion of lutein and zeaxanthin in the plasma and tissues of newly hatched chicks fed xanthophyll-free diets. One-day-old Leghorn chicks were randomly divided into two groups. A control group was fed a diet containing lutein and zeaxanthin (5.2 and 1.7 mg/kg diet, respectively) for 28 days. An experimental group was fed a diet containing no lutein and zeaxanthin for 28 days. Plasma and tissues were analyzed for lutein and zeaxanthin at 28 days (control) and on days 1, 14 and 28 (experimental). At hatching, lutein and zeaxanthin were the predominant carotenoids present in the blood and tissues. As indicated by their similar mass contents, there was complete transfer of these carotenoids from egg yolk to chick. Lutein and zeaxanthin concentrations in the plasma and tissues of chicks fed the xanthophyll-free diet decreased rapidly to almost zero (with a depletion time of seven days [t(1/2)]). In contrast, the retina retained its initial concentrations of lutein and zeaxanthin similar to the control group. meso-Zeaxanthin and cis-zeaxanthin were identified only in the retina. The retina concentrated zeaxanthin over lutein. Lutein and zeaxanthin were selectively retained in the retinas of chicks fed a xanthophyll-free diet. In contrast, the plasma and other tissues lost up to 90% of their original content of xanthophylls. These data emphasize the relative stability of lutein and zeaxanthin in the cone-rich retina where they are present as esters in oil droplets. The tissue depletion suggests the need for a regular dietary intake of lutein and zeaxanthin because of rapid depletion in the body. It is clear that these xanthophylls may have an essential role in the cone-rich retina of the chick as evidenced by their selective retention.

Animals↗

PubMed2007

Exercise training prevents arterial baroreflex dysfunction in rats treated with central angiotensin II.

Angiotensin II (Ang II)-induced arterial baroreflex dysfunction is associated with superoxide generation in the brain. Exercise training (EX) improves baroreflex function and decreases oxidative stress in cardiovascular diseases linked to elevated central Ang II. The aim of this study was to determine whether previous EX prevents baroreflex impairment caused by central administration of exogenous Ang II via an Ang II-superoxide mechanism. Four groups of rats were used: non-EX artificial cerebrospinal fluid infused, non-EX Ang II infused, EX artificial cerebrospinal fluid infused, and EX Ang II infused. Rats were treadmill trained for 3 to 4 weeks and subjected to intracerebroventricular infusion of Ang II over the last 3 days of EX. Twenty-four hours after the end of EX, the arterial baroreflex was assessed in anesthetized rats. Compared with non-EX artificial cerebrospinal fluid-infused rats, Ang II significantly decreased baroreflex sensitivity (maximum gain: 3.0+/-0.2% of maximum per millimeter of mercury versus 1.6+/-0.1% of maximum per millimeter of mercury; P<0.01), which was abolished by acute intracerebroventricular infusion of the Ang II type 1 receptor antagonist losartan and the reduced nicotinamide-adenine dinucleotide phosphate oxidase inhibitor apocynin. EX prevented the decrease in baroreflex sensitivity and downregulated Ang II type 1 receptor and NADPH oxidase subunit protein expression in the paraventricular nucleus of Ang II-infused rats. Finally, EX decreased superoxide production in the paraventricular nucleus of Ang II-infused rats. These results indicate that EX improves arterial baroreflex function in conditions of high brain Ang II, which is mediated by the central Ang II type 1 receptor and associated with a reduction in central oxidative stress.

Angiotensin II↗