Adenosine and adenosine receptor-mediated action in coronary microcirculation

Network pharmacology integrated with experimental validation to elucidate the mechanisms of action of the Guizhi-Gancao Decoction in the treatment of phenylephrine-induced cardiac hypertrophy

CONTEXT

The mechanisms of Traditional Chinese Medicine (TCM) Guizhi-Gancao Decoction (GGD) remain unknown.

OBJECTIVE

This study explores the mechanisms of GGD against cardiac hypertrophy.

MATERIALS AND METHODS

Network pharmacology analysis was carried out to identify the potential targets of GGD. In vivo experiments, C57BL/6J mice were divided into Con, phenylephrine (PE, 10 mg/kg/d), 2-chloroadenosine (CADO, the stable analogue of adenosine, 2 mg/kg/d), GGD (5.4 g/kg/d) and GGD (5.4 g/kg/d) + CGS15943 (a nonselective adenosine receptor antagonist, 4 mg/kg/d). In vitro experiments, primary neonatal rat cardiomyocytes (NRCM) were divided into Con, PE (100 µM), CADO (5 µM), GGD (10-5 g/mL) and GGD (10-5 g/mL) + CGS15943 (5 µM). Ultrasound, H&E and Masson staining, hypertrophic genes expression and cell surface area were conducted to verify the GGD efficacy. Adenosine receptors (ADORs) expression were tested via real-time polymerase chain reaction (PCR), western blotting and immunofluorescence analysis.

RESULTS

Network pharmacology identified ADORs among those of the core targets of GGD. In vitro experiments demonstrated that GGD attenuated PE-induced increased surface area (with an EC50 of 5.484 × 10-6 g/mL). In vivo data shown that GGD attenuated PE-induced ventricular wall thickening. In vitro and in vivo data indicated that GGD alleviated PE-induced hypertrophic gene expression (e.g., ANP, BNP and MYH7/MYH6), A1AR over-expression and A2aAR down-expression. Moreover, CADO exerts effects similar to GGD, whereas CGS15943 eliminated most effects of GGD.

DISCUSSION AND CONCLUSIONS

Our findings suggest the mechanism by which GGD inhibits cardiac hypertrophy, highlighting regulation of ADORs as a potential therapeutic strategy for HF.

Pd/Pa fluctuation with continuous ATP administration indicates inaccurate FFR measurement caused by insufficient hyperemia

Continuous intravenous adenosine triphosphate (ATP) administration is the standard method for inducing maximal hyperemia in fractional flow reserve (FFR) measurements. Several cases have demonstrated fluctuations in the ratio of mean distal coronary pressure to mean arterial pressure (Pd/Pa) value during ATP infusion, which raised our suspicions of FFR value inaccuracy. This study aimed to investigate our hypothesis that Pd/Pa fluctuations may indicate inaccurate FFR measurements caused by insufficient hyperemia. We examined 57 consecutive patients with angiographically intermediate coronary lesions who underwent fractional flow reverse (FFR) measurements in our hospital between November 2016 and September 2018. Pd/Pa was measured after continuous ATP administration (150 μg/kg/min) via a peripheral forearm vein for 5 min (FFRA); and we analyzed the FFR value variation in the final 20 s of the 5 min, defining 'Fluctuation' as variation range > 0.03. Then, 2 mg of nicorandil was administered into the coronary artery during continued ATP infusion, and the Pd/Pa was remeasured (FFRA+N). Fluctuations were observed in 23 of 57 patients. The cases demonstrating discrepancies of > 0.05 between FFRA and FFRA+N were observed more frequently in the fluctuation group than in the non-fluctuation group (12/23 vs. 1/34; p < 0.0001). The discrepancy between FFRA and FFRA+N values was smaller in the non-fluctuation group (mean difference ± SD; -0.00026 ± 0.04636 vs. 0.02608 ± 0.1316). Pd/Pa fluctuation with continuous ATP administration could indicate inaccurate FFR measurements caused by incomplete hyperemia. Additional vasodilator administration may achieve further hyperemia when Pd/Pa fluctuations are observed.

Adenosinergic system and nucleoside transporters in attention deficit hyperactivity disorder: Current findings

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder with high heterogeneity that can affect individuals of any age. It is characterized by three main symptoms: inattention, hyperactivity, and impulsivity. These neurobehavioral alterations and neurochemical and pharmacological findings are mainly attributed to unbalanced catecholaminergic signaling, especially involving dopaminergic pathways within prefrontal and striatal areas. Dopamine receptors and transporters are not solely implicated in this imbalance, as evidence indicates that the dopaminergic signaling is modulated by adenosine activity. To this extent, alterations in adenosinergic signaling are probably involved in ADHD. Here, we review the current knowledge about adenosine's role in the modulation of chemical, behavioral and cognitive parameters of ADHD, especially regarding dopaminergic signaling. Current literature usually links adenosine receptors signaling to the dopaminergic imbalance found in ADHD, but there is evidence that equilibrative nucleoside transporters (ENTs) could also be implicated as players in dopaminergic signaling alterations seen in ADHD, since their involvement in other neurobehavioral impairments.

Cross-sectional study on the impact of adverse childhood experiences on coronary flow reserve in male physicians with and without occupational burnout

OBJECTIVE

Physicians face documented challenges to their mental and physical well-being, particularly in the forms of occupational burnout and cardiovascular disease. This study examined the previously under-researched intersection of early life stressors, prolonged occupational stress, and cardiovascular health in physicians.

METHODS

Participants were 60 practicing male physicians, 30 with clinical burnout, defined by the Maslach Burnout Inventory, and 30 non-burnout controls. They completed the Adverse Childhood Experiences (ACE) Questionnaire asking about abuse, neglect and household dysfunctions before the age of 18, and the Perceived Stress Scale to rate thoughts and feelings about stress in the past month. Endothelium-independent (adenosine challenge) coronary flow reserve (CFR) and endothelium-dependent CFR (cold pressor test) were assessed by positron emission tomography-computed tomography. The segment stenosis score was determined by coronary computed tomography angiography.

RESULTS

Twenty-six (43%) participants reported at least one ACE and five (8%) reported ≥4 ACEs. A higher ACEs sum score was associated with lower endothelium-independent CFR (r partial (rp) = -0.347, p = .01) and endothelium-dependent CFR (rp = -0.278, p = .04), adjusting for age, body mass index, perceived stress and segment stenosis score. In exploratory analyses, participants with ≥4 ACEs had lower endothelium-independent CFR (rp = -0.419, p = .001) and endothelium-dependent CFR (rp = -0.278, p = .04), than those with <4 ACEs. Endothelium-dependent CFR was higher in physicians with burnout than in controls (rp = 0.277, p = .04). No significant interaction emerged between burnout and ACEs for CFR.

CONCLUSION

The findings suggest an independent association between ACEs and CFR in male physicians and emphasize the nuanced relationship between early life stressors, professional stress, and cardiovascular health.

Pericyte Dysfunction Contributes to Vascular Cognitive Impairment Induced by Chronic Cerebral Hypoperfusion in Rats

Vascular cognitive impairment (VCI) encompasses cognitive disorders associated with cerebrovascular disease, often manifesting as white matter lesions (WMLs), irrespective of precise triggers. The integrity of white matter is essential for neural communication and cognitive function maintenance. Persistent cerebral hypoperfusion-induced WMLs are now acknowledged as a key driver of VCI and dementia, though their exact formation mechanism remains unclear. Recent studies link pericyte dysfunction to diverse brain disorders like Alzheimer disease. However, the exact pathological connection between pericyte dysfunction and cognitive impairment in VCI remains unexplored. In this study, we aimed to examine whether pericyte dysfunction could impact WMLs and cognitive impairment in a rat VCI model. Using a rat model of chronic cerebral hypoperfusion-induced VCI through two-vessel occlusion (2VO), we verified that 2VO induced both WMLs and cognitive impairment. Notably, the number of pericytes in the brain was significantly altered after 2VO. Furthermore, we observed significantly increased capillary constrictions at pericyte bodies in the brains of 2VO-induced rats compared to sham-operated rats, accompanied by reduced cerebral blood flow (CBF). To tackle this issue, we administered CGS21680, a specific adenosine A2A subtype receptor agonist, intranasally twice a day for 7 days. We found that rats treated with CGS21680 exhibited a significant increase in CBF at 7 and 14 days after 2VO, compared to the vehicle group. Moreover, capillary lumens beneath pericytes also increased after the CGS21680 treatment. Importantly, the treatment led to substantial improvements in WMLs and cognitive impairment compared to the vehicle group. Our findings suggest a critical role of pericyte dysfunction in WMLs and cognitive impairment within the rat VCI model. This insight contributes to our understanding of pathogenesis and offers prospects for targeted intervention in VCI.

Association Between Global Sleep Quality and Coronary Microvascular Function in Male Physicians With Occupational Burnout

OBJECTIVE

Occupational burnout has been associated with an increased risk of coronary heart disease, although the mechanisms involved are elusive. We investigated whether poor global sleep quality is associated with impaired coronary microvascular function in male physicians, a professional group at increased risk of burnout.

METHODS

Study participants were 30 male physicians with clinical burnout and 30 controls without burnout defined by the Maslach Burnout Inventory. Global sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI). Endothelium-dependent (cold pressor test) and endothelium-independent (adenosine challenge) coronary microvascular functions were quantified with myocardial perfusion positron emission tomography. In multivariable analyses, the interaction between burnout and the PSQI global score was regressed on measures of coronary microvascular function, adjusting for age, body mass index, physical activity, alcohol consumption, and main effects of burnout and PSQI score.

RESULTS

The prevalence of poor sleepers (PSQI score >5) was 40% in the burnout group and 10% in the control group. Adjusting for covariates, burnout-by-global PSQI score interactions were observed for myocardial blood flow (MBF) at rest ( r partial = -0.30, p = .025), endothelium-dependent coronary flow reserve ( r partial = -0.26, p = .062), MBF response ( r partial = -0.30, p = .028), and hyperemic MBF ( r partial = -0.34, p = .012). The global PSQI score was inversely associated with these MBF measures in the burnout group relative to the control group. No significant interactions emerged for endothelium-independent MBF.

CONCLUSIONS

In male physicians with occupational burnout, poor global sleep quality was associated with reduced endothelium-dependent coronary microvascular function, suggesting a mechanism by which burnout may affect cardiovascular health.

Metabolites analysis and new bioactive compounds from the medicine food homology product of Cordyceps chanhua on artificial media

Cordyceps chanhua on artificial media has been approved as a medicine food homology product. However, the metabolites have not been extensively studied. HPLC-HRMS analysis showed that there were 11 main metabolites in the EtOAc extract including 4 probable unknown compounds. Fumosoroseain A with anti-aging effects is the most abundant known compound and was identified from C. chanhua for the first time. The second abundant compound is N6-(2-Hydroxyethyl) adenosine, a typical metabolite of C. chanhua. All the known compounds have consistent health function with that of the fungus. HRMS, 1D and 2D NMR analyses revealed that compounds 2, 3, and 4 are new nucleosides named as chanhuanosides A, B, and C. Compound 1 is the known compound cordyrrole B isolated from C. chanhua for the first time whose structure is firstly confirmed by single crystal X-ray analysis. Bioactivity analysis revealed that 1-4 significantly inhibited pancreatic lipase activity, and strongly promoted the proliferation of RAW264.7 and 293T cells, suggesting that they might have ant-obesity, immunoregulation, and renal protection functions. Structure-bioactivity analysis revealed that the esterification on ribose can increase their bioactivity. Present metabolites study suggests that C. chanhua cultured on the artificial medium is a promising health food.

Computed tomography myocardial perfusion imaging of patients with left ventricular hypertrophy in hypertension: A retrospective study

OBJECTIVE

Left ventricular hypertrophy (LVH) is a strong predictor of adverse cardiovascular outcomes including heart failure. This study evaluated characteristics and the influencing factors of computed tomography myocardial perfusion imaging (CT-MPI) of patients with LVH in hypertension.

METHODS

A total of 65 patients with stable chest pain and confirmed coronary stenosis <50% by coronary computed tomography angiography (cCTA) from September 2019 to February 2021 were recruited. According to the results of echocardiography, patients were divided into the LVH group (n = 33) and control group (patients without LVH, n = 32). The general data of all study subjects were collected, and the body mass index (BMI) and body surface area (BSA) were calculated. Myocardial blood flow (MBF), myocardial blood volume (MBV), and echocardiographic parameters were recorded. Spearman correlation analyses were conducted to analyze the relationship between MBF, MBV, and echocardiographic parameters.

RESULTS

The LVH group had significantly higher left ventricular end diastolic distance (LVEDd), septal wall thickness diastole (SWTd), and post wall thickness diastole (PWTd) than the control group, resulting in higher left ventricular mass index (LVMI) (P < .05). The LVH group showed significantly lower MBF than the control group (P < .05), but there was no significant difference in MBV between two groups (P > .05). Spearman correlation analysis demonstrated that MBF was negatively correlated with SWTd and LVMI (P < .05).

CONCLUSIONS

CT-MPI, as a new noninvasive modality to evaluate myocardial perfusion in hypertensive patients, revealed that MBF is reduced in patients with LVH, while MBV remains unchanged. In hypertensive patients, decreased MBF is significantly correlated with increased LVMI.

Accumulation of endogenous adenosine improves cardiomyocyte metabolism via epigenetic reprogramming in an ischemia-reperfusion model

Adenosine kinase (ADK) plays the major role in cardiac adenosine metabolism, so that inhibition of ADK increases myocardial adenosine levels. While the cardioprotective actions of extracellular adenosine against ischemia/reperfusion (I/R) are well-established, the role of cellular adenosine in protection against I/R remains unknown. Here we investigated the role of cellular adenosine in epigenetic regulation on cardiomyocyte gene expression, glucose metabolism and tolerance to I/R. Evans blue/TTC staining and echocardiography were used to assess the extent of I/R injury in mice. Glucose metabolism was evaluated by positron emission tomography and computed tomography (PET/CT). Methylated DNA immunoprecipitation (MeDIP) and bisulfite sequencing PCR (BSP) were used to evaluate DNA methylation. Lentiviral/adenovirus transduction was used to overexpress DNMT1, and the OSI-906 was administered to inhibit IGF-1. Cardiomyocyte-specific ADK/IGF-1-knockout mice were used for mechanistic experiments.Cardiomyocyte-specific ADK knockout enhanced glucose metabolism and ameliorated myocardial I/R injury in vivo. Mechanistically, ADK deletion caused cellular adenosine accumulation, decreased DNA methyltransferase 1 (DNMT1) expression and caused hypomethylation of multiple metabolic genes, including insulin growth factor 1 (IGF-1). DNMT1 overexpression abrogated these beneficial effects by enhancing apoptosis and decreasing IGF-1 expression. Inhibition of IGF-1 signaling with OSI-906 or genetic knocking down of IGF-1 also abrogated the cardioprotective effects of ADK knockout, revealing the therapeutic potential of increasing IGF-1 expression in attenuating myocardial I/R injury. In conclusion, the present study demonstrated that cardiomyocyte ADK deletion ameliorates myocardial I/R injury via epigenetic upregulation of IGF-1 expression via the cardiomyocyte adenosine/DNMT1/IGF-1 axis.

dECM based dusal-responsive vascular graft with enzyme-controlled adenine release for long-term patency

Rapid occlusion is the culprit leading to implantation failure of biological blood vessels. Although adenosine is a clinical-proven drug to overcome the problem, its short half-life and turbulent burst-release limit its direct application. Thus, a pH/temperature dual-responsive blood vessel possessed controllable long-term adenosine secretion was constructed based on acellular matrix via compact crosslinking by oxidized chondroitin sulfate (OCSA) and functionalized with apyrase and acid phosphatase. These enzymes, as adenosine micro-generators, controlled the adenosine release amount by "real-time-responding" to acidity and temperature of vascular inflammation sites. Additionally, the macrophage phenotype was switched from M1 to M2, and related factors expression proved that adenosine release was effectively regulated with the severity of inflammation. What's more, the ultra-structure for degradation resisting and endothelialization accelerating was also preserved by their "double-crosslinking". Therefore, this work suggested a new feasible strategy providing a bright future of long-term patency for transplanted blood vessels.

Protection against Ischemic Heart Disease: A Joint Role for eNOS and the KATP Channel

Genetic susceptibility may influence ischemic heart disease (IHD) predisposition and affect coronary blood flow (CBF) regulation mechanisms. The aim of this study was to investigate the association among single nucleotide polymorphisms (SNPs) of genes encoding for proteins involved in CBF regulation and IHD. A total of 468 consecutive patients were enrolled and divided into three groups according to coronary angiography and intracoronary functional tests results: G1, patients with coronary artery disease (CAD); G2, patients with coronary microvascular dysfunction (CMD); and G3, patients with angiographic and functionally normal coronary arteries. A genetic analysis of the SNPs rs5215 of the potassium inwardly rectifying channel subfamily J member 11 (KCNJ11) gene and rs1799983 of the nitric oxide synthase 3 (NOS3) gene, respectively encoding for the Kir6.2 subunit of ATP sensitive potassium (K_ATP) channels and nitric oxide synthase (eNOS), was performed on peripheral whole blood samples. A significant association of rs5215_G/G of KCNJ11 and rs1799983_T/T of NOS3 genes was detected in healthy controls compared with CAD and CMD patients. Based on univariable and multivariable analyses, the co-presence of rs5215_G/G of KCNJ11 and rs1799983_T/T of NOS3 may represent an independent protective factor against IHD, regardless of cardiovascular risk factors. This study supports the hypothesis that SNP association may influence the crosstalk between eNOS and the K_ATP channel that provides a potential protective effect against IHD.

Purinergic signaling in myocardial ischemia-reperfusion injury

Purines and their derivatives, extensively distributed in the body, act as a class of extracellular signaling molecules via a rich array of receptors, also known as purinoceptors (P1, P2X, and P2Y). They mediate multiple intracellular signal transduction pathways and participate in various physiological and pathological cell behaviors. Since the function in myocardial ischemia-reperfusion injury (MIRI), this review summarized the involvement of purinergic signal transduction in diversified pathological processes, including energy metabolism disorder, oxidative stress injury, calcium overload, inflammatory immune response, platelet aggregation, coronary vascular dysfunction, and cell necrosis and apoptosis. Moreover, increasing evidence suggests that purinergic signaling also mediates the prevention and treatment of MIRI, such as ischemic conditioning, pharmacological intervention, and some other therapies. In conclusion, this review exhibited that purinergic signaling mediates the complex processes of MIRI which shows its promising application and prospecting in the future.

Coronary Microvascular Dysfunction in Patients with Congenital Heart Disease

Congenital heart diseases represent a wide range of cardiac malformations. Medical and surgical advances have dramatically increased the survival of patients with congenital heart disease, leading to a continuously growing number of children, adolescents, and adults with congenital heart disease. Nevertheless, congenital heart disease patients have a worse prognosis compared to healthy individuals of similar age. There is substantial overlap in the pathophysiology of congenital heart disease and heart failure induced by other etiologies. Among the pathophysiological changes in heart failure, coronary microvascular dysfunction has recently emerged as a crucial modulator of disease initiation and progression. Similarly, coronary microvascular dysfunction could be important in the pathophysiology of congenital heart diseases as well. For this systematic review, studies on maximal vasodilatory capacity in the coronary microvascular bed in patients with congenital heart disease were searched using the PubMed database. To date, coronary microvascular dysfunction in congenital heart disease patients is incompletely understood because studies on this topic are rare and heterogeneous. The prevalence, extent, and pathophysiological relevance of coronary microvascular dysfunction in congenital heart diseases remain to be elucidated. Herein, we discuss what is currently known about coronary microvascular dysfunction in congenital heart disease and future directions.

Purinergic Signaling in Oral Tissues

The role of the purinergic signal has been extensively investigated in many tissues and related organs, including the central and peripheral nervous systems as well as the gastrointestinal, cardiovascular, respiratory, renal, and immune systems. Less attention has been paid to the influence of purines in the oral cavity, which is the first part of the digestive apparatus and also acts as the body’s first antimicrobial barrier. In this review, evidence is provided of the presence and possible physiological role of the purinergic system in the different structures forming the oral cavity including teeth, tongue, hard palate, and soft palate with their annexes such as taste buds, salivary glands, and nervous fibers innervating the oral structures. We also report findings on the involvement of the purinergic signal in pathological conditions affecting the oral apparatus such as Sjögren’s syndrome or following irradiation for the treatment of head and neck cancer, and the use of experimental drugs interfering with the purine system to improve bone healing after damage. Further investigations are required to translate the results obtained so far into the clinical setting in order to pave the way for a wider application of purine-based treatments in oral diseases.

Adenosine A2a Receptor Regulates Autophagy Flux and Apoptosis to Alleviate Ischemia-Reperfusion Injury via the cAMP/PKA Signaling Pathway

Exploring effective methods to lessen myocardial ischemia-reperfusion injury still has positive significance. The adenosine A2a receptor (A2aR) has played a crucial part in cardiac ischemia-reperfusion injury. Previous studies revealed that the adenosine A2a receptor regulated autophagy, but the specific mechanism in myocardial ischemia-reperfusion injury was still unclear. We established an ischemia-reperfusion model (30 min of ischemia and 2 h of reperfusion) in vivo and a model with oxygen-glucose deprivation for 6 h and reoxygenation for 18 h (OGDR) in vitro. The ischemia-reperfusion injury resulted in prolonged QTc interval, left ventricular systolic dysfunction, and myocardial infarction. In vitro model, we found that the OGDR-induced autophagosomes and apoptosis caused myocardial cell death, as evidenced by a significant increase in the generation of lactate dehydrogenase and creatine kinase-MB. Furthermore, overactivated autophagy with rapamycin showed an anti-apoptotic effect. The interaction between autophagy and apoptosis in myocardial ischemia-reperfusion injury was complex and variable. We discovered that the activation of adenosine A2a receptor could promote the expression of Bcl-2 to inhibit the levels of Beclin-1 and LC3II. The number of autophagosomes exceeded that of autolysosomes under OGDR, but the result reversed after A2aR activation. Activated A2aR with its agonist CGS21680 before reperfusion saved cellular survival through anti-apoptosis and anti-autophagy effect, thus improving ventricular contraction disorders, and visibly reducing myocardial infarction size. The myocardial protection of adenosine A2a receptor after ischemia may involve the cAMP-PKA signaling pathway and the interaction of Bcl-2-Beclin-1.

NADPH oxidase 4 contributes to TRPV4-mediated endothelium-dependent vasodilation in human arterioles by regulating protein phosphorylation of TRPV4 channels

Impaired endothelium-dependent vasodilation has been suggested to be a key component of coronary microvascular dysfunction (CMD). A better understanding of endothelial pathways involved in vasodilation in human arterioles may provide new insight into the mechanisms of CMD. The goal of this study is to investigate the role of TRPV4, NOX4, and their interaction in human arterioles and examine the underlying mechanisms. Arterioles were freshly isolated from adipose and heart tissues obtained from 71 patients without coronary artery disease, and vascular reactivity was studied by videomicroscopy. In human adipose arterioles (HAA), ACh-induced dilation was significantly reduced by TRPV4 inhibitor HC067047 and by NOX 1/4 inhibitor GKT137831, but GKT137831 did not further affect the dilation in the presence of TRPV4 inhibitors. GKT137831 also inhibited TRPV4 agonist GSK1016790A-induced dilation in HAA and human coronary arterioles (HCA). NOX4 transcripts and proteins were detected in endothelial cells of HAA and HCA. Using fura-2 imaging, GKT137831 significantly reduced GSK1016790A-induced Ca²⁺ influx in the primary culture of endothelial cells and TRPV4-WT-overexpressing human coronary artery endothelial cells (HCAEC). However, GKT137831 did not affect TRPV4-mediated Ca²⁺ influx in non-phosphorylatable TRPV4-S823A/S824A-overexpressing HCAEC. In addition, treatment of HCAEC with GKT137831 decreased the phosphorylation level of Ser824 in TRPV4. Finally, proximity ligation assay (PLA) revealed co-localization of NOX4 and TRPV4 proteins. In conclusion, both TRPV4 and NOX4 contribute to ACh-induced dilation in human arterioles from patients without coronary artery disease. NOX4 increases TRPV4 phosphorylation in endothelial cells, which in turn enhances TRPV4-mediated Ca²⁺ entry and subsequent endothelium-dependent dilation in human arterioles.

Correlation Between Retinopathy and Coronary Microcirculation Dysfunction in Patients with Type 2 Diabetes Mellitus

Purpose

The aim of this study is to evaluate the correlation between retinopathy and coronary microcirculation dysfunction (CMD) in type 2 diabetes mellitus (T2DM) patients.

Methods

198 T2DM patients with left ventricular ejection fraction (LVEF)>50%, no epicardial coronary artery stenosis diagnosis by coronary angiography (CAG) and successfully completed coronary blood flow reserve (CFR) test and laboratory examination were enrolled, and fundus examination was performed on all participants. Two groups were divided according to CFR value, including 86 patients with CMD (CFR≤2.5) in study group and 112 patients without CMD (CFR>2.5) in control group. The composition of various retinopathy in two groups was observed, and the correlation between retinopathy and CMD was analyzed using ordered logistic regression.

Results

There were 13 cases with arteriovenous (A/V) nicking, 4 cases with proliferative diabetic retinopathy (PDR), 14 cases with non-proliferative diabetic retinopathy (NPDR), 17 cases with diabetic retinopathy (DR) with A/V nicking, 38 cases without retinopathy in study group, and 18 cases, 7 cases, 20 cases, 4 cases and 63 cases for each in control group. After adjustment for age, gender, hypertension, diabetes duration, dyslipidemia, glycosylated hemoglobin (HbA1c), body mass index (BMI), A/V nicking, PDR and NPDR, the diference of DR with A/V nicking between study and control group remained statistically signifcant (OR 2.0, 95% CI 0.79 to 3.21, p = 0.001).

Conclusion

DR with A/V nicking could be used as an independent predictor of T2DM patients with CMD. CFR testing should be performed on patients with this kind of eye sign, even if they do not have any symptoms of heart disease. Meanwhile, DR with A/V nicking might be served as a reference indicator of CMD in T2DM patients with chest pain who were unable to be tested for CFR.

High spatio-temporal resolution measurement of A1 R and A2A R interactions combined with Iem-spFRET and E-FRET methods

A₁ R-A_2A R heterodimers regulate striatal glutamatergic neurotransmission. However, few researches about kinetics have been reported. Here, we combined Iem-spFRET and E-FRET to investigate the kinetics of A₁ R and A_2A R interaction. Iem-spFRET obtains the energy transfer efficiency of the whole cell. E-FRET gets energy transfer efficiency with high spatial resolution, whereas, it was prone to biases because background was easily selected due to manual operation. To study the interaction with high spatio-temporal resolution, Iem-spFRET was used to correct the deviation of E-FRET. In this paper, A₁ R and A_2A R interaction was monitored, and the changes of FRET efficiency of the whole or/and partial cell membrane were described. The results showed that activation of A₁ R or A_2A R leads to rapid aggregation, inhibition of A₁ R or A_2A R leads to slow segregation, and the interaction is reversible. These results demonstrated that combination of Iem-spFRET and E-FRET could measure A₁ R and A_2A R interaction with high spatio-temporal resolution.

Purinergic interplay between erythrocytes and platelets in diabetes-associated vascular dysfunction

Cardiovascular complications in diabetes are the leading causes for high morbidity and mortality. It has been shown that alteration of purinergic signaling contributes to diabetes-associated cardiovascular complications. Red blood cells (RBCs) and platelets play a fundamental role in regulation of oxygen transport and hemostasis, respectively. Of note, these cells undergo purinergic dysfunction in diabetes. Recent studies have established a novel function of RBCs as disease mediators for the development of endothelial dysfunction in type 2 diabetes (T2D). RBC-released ATP is defective in T2D, which has implication for induction of vascular dysfunction by dysregulating purinergic signaling. Platelets are hyperactive in diabetes. ADP-mediated P2Y₁ and P2Y₁₂ receptor activation contributes to platelet aggregation and targeting P2Y receptors particularly P2Y₁₂ receptor in platelets is effective for the treatment of cardiovascular events. In contrast to other P2Y₁₂ receptor antagonists, platelet-targeting drug ticagrelor has potential to initiate purinergic signaling in RBCs for the beneficial cardiovascular outcomes. It is increasingly clear that altered vascular purinergic signaling mediated by various nucleotides and nucleoside contributes to diabetes-associated vascular dysfunction. However, the contribution of complex purinergic networks between RBCs and platelets to the vascular dysfunction in diabetes remains unclear. This study discusses the possible interplay of RBCs and platelets via the purinergic network for diabetes-associated vascular dysfunction.

Neutrophil-to-lymphocyte ratio is associated with coronary microvascular dysfunction in type 2 diabetes mellitus patients

AIMS

Our study is aimed to investigate the relationship between neutrophil-to-lymphocyte ratio (NLR) and coronary microvascular dysfunction (CMD) in type 2 diabetes mellitus (T2DM) patients.

METHODS

We retrospect the consecutive medical files of 160 T2DM patients and recorded their clinical information and laboratory findings. Patients were divided into CMD group (n = 87) and non-CMD group (n = 73). We compared the NLR values of the two groups. Meanwhile we also observed the prevalence of CMD at different NLR levels. Then, logistic regression and ROC analysis were performed.

RESULTS

NLR value of CMD group was significantly lower than non-CMD group (2.01 ± 0.74 vs 2.53 ± 0.69, P＜0.001). Prevalence of CMD in low (NLR ≤ 1.53, n = 30), medium (1.53 < NLR ≤ 2.20, n = 53) and high (NLR > 2.20, n = 77) group were 90%, 61.1%, and 39.2% respectively. The prevalence of CMD significantly increased as NLR level decreased. After adjusting potential related factors, NLR was still significantly correlated with CMD (OR = 0.295, 95 %CI:0.162-0.539, P < 0.001). The area under ROC curve (AUC) was 0.707 (95 %CI:0.627-0.786, P < 0.001).

CONCLUSIONS

Our results showed that NLR is associated with CMD in T2DM patients, and the prevalence of CMD may increase as NLR level decrease.