Adenosine kinase inhibition protects mice from abdominal aortic aneurysm via epigenetic modulation of VSMC inflammation.

AIM: Abdominal aortic aneurysm (AAA) is a common, serious vascular disease with no effective pharmacological treatment. The nucleoside adenosine plays an important role in modulating vascular homeostasis, which prompted us to determine whether adenosine kinase (ADK), an adenosine metabolizing enzyme, modulates AAA formation via control of intracellular adenosine level, and to investigate the underlying mechanisms. METHODS AND RESULTS: We used a combination of genetic and pharmacological approaches in murine models of AAA induced by calcium chloride (CaCl2) application or angiotensin II (Ang II) infusion to study the role of ADK in the development of AAA. In vitro functional assays were performed by knocking down ADK with adenovirus-short hairpin RNA in human vascular smooth muscle cells (VSMCs), and the molecular mechanisms underlying ADK function were investigated using RNA-sequencing, isotope tracing and chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR). Heterozygous deficiency of Adk protected mice from CaCl2- and Ang II-induced AAA formation. Moreover, specific knockout of Adk in VSMCs prevented Ang II-induced AAA formation, as evidenced by reduced aortic extracellular elastin fragmentation, neovascularization and aortic inflammation. Mechanistically, ADK knockdown in VSMCs markedly suppressed the expression of inflammatory genes associated with AAA formation, and these effects were independent of adenosine receptors. Metabolic flux and ChIP-qPCR results showed that ADK knockdown in VSMCs decreased S-adenosylmethionine (SAM)-dependent transmethylation, thereby reducing H3K4me3 binding to the promoter regions of the genes that are associated with inflammation, angiogenesis and extracellular elastin fragmentation. Furthermore, the ADK inhibitor ABT702 protected mice from CaCl2-induced aortic inflammation, extracellular elastin fragmentation and AAA formation. CONCLUSION: Our findings reveal a novel role for ADK inhibition in attenuating AAA via epigenetic modulation of key inflammatory genes linked to AAA pathogenesis.

Blockade of endothelial adenosine receptor 2 A suppresses atherosclerosis in vivo through inhibiting CREB-ALK5-mediated endothelial to mesenchymal transition.

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, and morbidity and mortality rates continue to rise. Atherosclerosis constitutes the principal etiology of CVDs. Endothelial injury, inflammation, and dysfunction are the initiating factors of atherosclerosis. Recently, we reported that endothelial adenosine receptor 2 A (ADORA2A), a G protein-coupled receptor (GPCR), plays critical roles in neovascularization disease and cerebrovascular disease. However, the precise role of endothelial ADORA2A in atherosclerosis is still not fully understood. Here, we showed that ADORA2A expression was markedly increased in the aortic endothelium of humans with atherosclerosis or Apoe-/- mice fed a high-cholesterol diet. In vivo studies unraveled that endothelial-specific Adora2a deficiency alleviated endothelial-to-mesenchymal transition (EndMT) and prevented the formation and instability of atherosclerotic plaque in Apoe-/- mice. Moreover, pharmacologic inhibition of ADORA2A with KW6002 recapitulated the anti-atherogenic phenotypes observed in genetically Adora2a-deficient mice. In cultured human aortic endothelial cells (HAECs), siRNA knockdown of ADORA2A or KW6002 inhibition of ADORA2A decreased EndMT, whereas adenoviral overexpression of ADORA2A induced EndMT. Mechanistically, ADORA2A upregulated ALK5 expression via a cAMP/PKA/CREB axis, leading to TGFß-Smad2/3 signaling activation, thereby promoting EndMT. In conclusion, these findings, for the first time, demonstrate that blockade of ADORA2A attenuated atherosclerosis via inhibition of EndMT induced by the CREB1-ALK5 axis. This study discloses a new link between endothelial ADORA2A and EndMT and indicates that inhibiting endothelial ADORA2A could be an effective novel strategy for the prevention and treatment of atherosclerotic CVDs.

Inactivation of adenosine receptor 2A suppresses endothelial-to-mesenchymal transition and inhibits subretinal fibrosis in mice.

Anti-vascular endothelial growth factor therapy has had a substantial impact on the treatment of choroidal neovascularization (CNV) in patients with neovascular age-related macular degeneration (nAMD), the leading cause of vision loss in older adults. Despite treatment, many patients with nAMD still develop severe and irreversible visual impairment because of the development of subretinal fibrosis. We recently reported the anti-inflammatory and antiangiogenic effects of inhibiting the gene encoding adenosine receptor 2A (Adora2a), which has been implicated in cardiovascular disease. Here, using two mouse models of subretinal fibrosis (mice with laser injury-induced CNV or mice with a deficiency in the very low-density lipoprotein receptor), we found that deletion of Adora2a either globally or specifically in endothelial cells reduced subretinal fibrosis independently of angiogenesis. We showed that Adora2a-dependent endothelial-to-mesenchymal transition contributed to the development of subretinal fibrosis in mice with laser injury-induced CNV. Deficiency of Adora2a in cultured mouse and human choroidal endothelial cells suppressed induction of the endothelial-to-mesenchymal transition. A metabolomics analysis of cultured human choroidal endothelial cells showed that ADORA2A knockdown with an siRNA reversed the increase in succinate because of decreased succinate dehydrogenase B expression under fibrotic conditions. Pharmacological inhibition of ADORA2A with a small-molecule KW6002 in both mouse models recapitulated the reduction in subretinal fibrosis observed in mice with genetic deletion of Adora2a. ADORA2A inhibition may be a therapeutic approach to treat subretinal fibrosis associated with nAMD.

Purine synthesis suppression reduces the development and progression of pulmonary hypertension in rodent models.

AIMS: Proliferation of vascular smooth muscle cells (VSMCs) is a hallmark of pulmonary hypertension (PH). Proliferative cells utilize purine bases from the de novo purine synthesis (DNPS) pathways for nucleotide synthesis; however, it is unclear whether DNPS plays a critical role in VSMC proliferation during development of PH. The last two steps of DNPS are catalysed by the enzyme 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase (ATIC). This study investigated whether ATIC-driven DNPS affects the proliferation of pulmonary artery smooth muscle cells (PASMCs) and the development of PH. METHODS AND RESULTS: Metabolites of DNPS in proliferative PASMCs were measured by liquid chromatography-tandem mass spectrometry. ATIC expression was assessed in platelet-derived growth factor-treated PASMCs and in the lungs of PH rodents and patients with pulmonary arterial hypertension. Mice with global and VSMC-specific knockout of Atic were utilized to investigate the role of ATIC in both hypoxia- and lung interleukin-6/hypoxia-induced murine PH. ATIC-mediated DNPS at the mRNA, protein, and enzymatic activity levels were increased in platelet-derived growth factor-treated PASMCs or PASMCs from PH rodents and patients with pulmonary arterial hypertension. In cultured PASMCs, ATIC knockdown decreased DNPS and nucleic acid DNA/RNA synthesis, and reduced cell proliferation. Global or VSMC-specific knockout of Atic attenuated vascular remodelling and inhibited the development and progression of both hypoxia- and lung IL-6/hypoxia-induced PH in mice. CONCLUSION: Targeting ATIC-mediated DNPS compromises the availability of purine nucleotides for incorporation into DNA/RNA, reducing PASMC proliferation and pulmonary vascular remodelling and ameliorating the development and progression of PH.

Identification and Validation of a Ferroptosis-Related Signature for Predicting Prognosis and Immune Microenvironment in Papillary Renal Cell Carcinoma.

Objective: We aimed to explore the prognostic patterns of ferroptosis-related genes in papillary renal cell carcinoma (PRCC) and investigate the relationship between ferroptosis-related genes and PRCC tumor immune microenvironment. Methods: We obtained the mRNA expression and corresponding clinical data of PRCC from the public tumor cancer genome atlas database (TCGA). The PRCC patients were randomly divided into two cohort, training cohort and verification cohort, respectively. Univariate Cox regression, LASSO Cox regression, multivariate Cox regression analysis were utilized to construct ferroptosis signature for PRCC patients. And then, risk prognostic model was established and verified. The correlation of ferroptosis-related signature with survival and immune microenvironment was systematically analyzed. Results: A 4-genes ferroptosis signature (CDKN1A, MIOX, PSAT1, and RRM2) was constructed. Multivariate Cox regression assay indicates that the risk score of ferroptosis signature was an independent prognostic indicator (HR=1.391, p<0.001). The survival curve shows that the high-risk group has a poorer prognosis than the low-risk group (p<0.001). The risk prognostic model was established based on prognostic factors of clinical-stage, hemoglobin, and risk score. The time-dependent receiver operating characteristic curve (ROC) analysis proves the predictive capacity of the ferroptosis signature, the 3 years area under the curve (AUC) is 0.890, and the 5 years AUC is 0.733. Further analysis suggested that cell cycle, pentose phosphate pathway, P53 signaling pathway were significantly enriched in the high-risk group. The significantly different fractions of dendritic cells resting, macrophage cells, and T cells follicular helper were observed in risk groups. Conclusion: This study implicates a ferroptosis signature which has a good predict capacity of the prognosis in PRCC patients. Ferroptosis-related genes may have a key role in the process of anti-tumor and serve as therapeutic targets for PRCC.

Effects of insoluble dietary fiber from kiwi fruit pomace on the physicochemical properties and sensory characteristics of low-fat pork meatballs.

ABSTRACT: As beverage industry by product, kiwi fruit pomace is potential but underutilized. In this study, insoluble dietary fiber from kiwi fruit pomace was modified via ultra-fine pulverization. The physicochemical and functional properties of kiwi fruit insoluble dietary fiber (KWIDF) superfine powder and its application in pork meatballs as a fat substitute were investigated. The SEM and droplet size measurement results revealed that the specific surface area of KWIDF increased from 44.4 to 192.9 m2 kg-1. The swelling capacity, water-, oil- and fat-holding capacities increased by 51.61%, 40.21%, 46.09% and 47.01%, respectively. The poisonous substances adsorbing abilities and the inhibition of enzyme activities were also improved. Similarly, KWIDF adsorbed cholesterol and glucose preferably. In addition, KWIDF revealed significant dose-response effects on the nutritional within a meat matrix, quality and sensory characteristics in meatballs (P < 0.05). The addition of 3% KWIDF superfine powder was found most suitable with high acceptability overall.

Facile synthesis of self-healing and layered sodium alginate/polyacrylamide hydrogel promoted by dynamic hydrogen bond.

Hydrogels are widely used in many fields but generally suffer from low mechanical strength and poor self-healing performance. Here, a novel and facile method was developed to prepare a semi-interpenetrating polymer network (semi-IPN) hydrogel with layered structure and improved properties based on sodium alginate (SA) and polyacrylamide (PAM). Systematic characterizations revealed a formation mechanism of layered structure via hydrogen bonds (HBs) promoted self-assembly of SA in the porous PAM matrix. Also, HBs can also display a key role in enhancing self-healing of the hydrogel, by which the hydrogel possesses a self-healing capacity of 99 % with sprayed by a few of water. Moreover, the layered semi-IPN structure makes the tensile strength of PAMSA hydrogel reach 266 kPa. The fabricated PAMSA hydrogel with layered microstructure containing SA provides a protocol to broaden the functionality and variety of the hydrogels.

The developmental difference of inattentional blindness in 3-to-5-year-old preschoolers and its relationship with fluid intelligence.

Preschoolers can focus on the events that they are interested in and shield other information that may still be obvious and important, and this phenomenon is termed as inattentional blindness (IB). The present study investigated the developmental differences in IB and explored its relationship with fluid intelligence in 3-to-5-year-old preschoolers. With the involvement of one hundred and thirty-five preschoolers, it was found that the IB rates decreased with age during 3-to-5-year-olds. Fluid intelligence could significantly predict the incidence of IB in 4-year-olds, which means that those with higher fluid intelligence scores experience less IB. It implied that the ability to detect unintentional stimuli increased from 3-to-5-year-olds, whereas age was an impact factor to the relationship between fluid intelligence and IB.