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Biomedical subjects

Yao Hu

Publications and source records attributed to Yao Hu.

3 recordsLinked to original sources

Halorubrum marinum sp. nov., Halorubrum rarum sp. nov., Halorubrum wangae sp. nov., Halorubrum shenae sp. nov., and Halorubrum zhoui sp. nov., halophilic archaea from coastal tidal flats, a saline lake, and a marine solar saltern.

Five novel halophilic archaeal strains, designated DTA46T, DTA98T, HHNYT27T, N11T, and SY-15T, were isolated from diverse saline environments across various regions of China. Amplicon and metagenome analyses revealed that three amplicon reads were affiliated with strains DTA46T, HHNYT27T, and N11T while two MAGs related to strains N11T and SY-15T. The sequence similarities among these five strains and current species of the genus Halorubrum were 93.1%-99.1% and 86.0%-95.9% judged by 16S rRNA and rpoB' genes, respectively. Phylogenomic and comparative genomic analyses revealed their close affiliation with Halorubrum. The average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), and average amino acid identity (AAI) values between these strains and existing Halorubrum species ranged from 74.9%-93.6%, 22.3%-58.3%, and 68.3%-93.7%, respectively. All are below the recommended thresholds for species delineation, which supports their classification as novel taxa. The growth characteristics of strains DTA46T, DTA98T, HHNYT27T, N11T, and SY-15T were determined as follows: temperature range 20-60 °C (optima: 35, 37-42, 37, 35, and 42 °C), NaCl concentration 1.4-5.5 M (optima: 2.6, 3.1, 3.1, 3.1, and 5.1 M), and pH range 5.5-9.5 (optima: 8.0, 8.0, 7.0, 7.5, and 7.0). Based on the polyphasic characterization integrating phenotypic, chemotaxonomic, phylogenetic, and phylogenomic evidence, strains DTA46T, DTA98T, HHNYT27T, N11T, and SY-15T are proposed to represent five novel species of the genus Halorubrum, for which the names Halorubrum marinum sp. nov., Halorubrum rarum sp. nov., Halorubrum wangae sp. nov., Halorubrum shenae sp. nov., and Halorubrum zhoui sp. nov. are designated, respectively.

Phylogeny

Epigenetic mechanisms underlying variation of IL-6, a well-established inflammation biomarker and risk factor for cardiovascular disease.

BACKGROUND AND AIMS: Cardiovascular disease (CVD) is one of the leading causes of morbidity and mortality worldwide, yet the underlying molecular mechanisms remain less understood. Chronic low-grade inflammation is a complex immune response contributing to the pathophysiology of cardiovascular disease. This response is signaled in part by interleukin-6 (IL-6), a pleiotropic, pro-inflammatory cytokine. Phenotypic variance in circulating IL-6 level may be explained in part by DNA methylation which is increasingly being associated with cardiovascular effects. METHODS: In this study we evaluated methylated DNA (CpG sites) associated with blood IL-6 levels across &#x223c;4,400 ancestrally diverse individuals (81&#xa0;% self-reported White; 9&#xa0;% Black or African American, 8&#xa0;% Hispanic or Latino/a, and 2&#xa0;% Chinese American). RESULTS: We identified 178 CpG sites associated with IL-6 (p<0.05/&#x223c;395,000). Among the sites, cg04437762 is located within the transcription unit of IL6R, a current therapeutic target for inflammatory disease, and cg26692003 and cg00464927 were significant for IL6 and IL6ST trans-CpG-gene transcripts. Functional gene expression downstream of methylation identified cellular response to IL-6 and B-cell regulation and activation pathways. Four genes were linked with both a genetic component of cardiovascular disease and an IL-6 associated CpG site. Three CpG sites identified through Mendelian randomization analyses supported inference of a causal effect on IL-6 levels, including the LYN gene that regulates immune cell signaling and has been previously associated with atherosclerosis. CONCLUSIONS: Overall, we identified several novel IL-6-CpG sites and downstream pathways affected by methylation. Follow-up functional studies including the regulation of IL-6 would complement current knowledge of CVD pathophysiology and potential therapeutic targets.

Humans

Rare damaging CCR2 variants are associated with lower lifetime cardiovascular risk.

BACKGROUND: Previous work has shown a role of CCL2, a key chemokine governing monocyte trafficking, in atherosclerosis. However, it remains unknown whether targeting CCR2, the cognate receptor of CCL2, provides protection against human atherosclerotic cardiovascular disease. METHODS: Computationally predicted damaging or loss-of-function (REVEL&#x2009;>&#x2009;0.5) variants within CCR2 were detected in whole-exome-sequencing data from 454,775 UK Biobank participants and tested for association with cardiovascular endpoints in gene-burden tests. Given the key role of CCR2 in monocyte mobilization, variants associated with lower monocyte count were prioritized for experimental validation. The response to CCL2 of human cells transfected with these variants was tested in migration and cAMP assays. Validated damaging variants were tested for association with cardiovascular endpoints, atherosclerosis burden, and vascular risk factors. Significant associations were replicated in six independent datasets (n&#x2009;=&#x2009;1,062,595). RESULTS: Carriers of 45 predicted damaging or loss-of-function CCR2 variants (n&#x2009;=&#x2009;787 individuals) were at lower risk of myocardial infarction and coronary artery disease. One of these variants (M249K, n&#x2009;=&#x2009;585, 0.15% of European ancestry individuals) was associated with lower monocyte count and with both decreased downstream signaling and chemoattraction in response to CCL2. While M249K showed no association with conventional vascular risk factors, it was consistently associated with a lower risk of myocardial infarction (odds ratio [OR]: 0.66, 95% confidence interval [CI]: 0.54-0.81, p&#x2009;=&#x2009;6.1&#x2009;&#xd7;&#x2009;10-5) and coronary artery disease (OR: 0.74, 95%CI: 0.63-0.87, p&#x2009;=&#x2009;2.9&#x2009;&#xd7;&#x2009;10-4) in the UK Biobank and in six replication cohorts. In a phenome-wide association study, there was no evidence of a higher risk of infections among M249K carriers. CONCLUSIONS: Carriers of an experimentally confirmed damaging CCR2 variant are at a lower lifetime risk of myocardial infarction and coronary artery disease without carrying a higher risk of infections. Our findings provide genetic support for the translational potential of CCR2-targeting as an atheroprotective approach.

Humans