An SN1-Approach to Cross-Coupling: Deoxygenative Arylation Facilitated by the ß-Silicon Effect.

We report a dual metal-catalyzed method for the cross-coupling of unprotected alcohols by exploiting the ß-Si effect. This deoxygenative Suzuki-Miyaura reaction tolerates a range of primary, secondary, and tertiary alcohol substrates along with diverse functional groups and heterocycles. Mechanistic experiments including KIE, VTNA, and Eyring analyses suggest the existence of a carbocation intermediate on the reaction pathway, consistent with a rare SN1 pathway for the activation of an electrophile in cross-coupling reactions. A novel bis-imidazolium N-heterocyclic carbene (NHC) ligand was found to be optimal for reactivity, and nickel(0)-, nickel(I)- and nickel(II)- complexes of this ligand were isolated and characterized. In contrast to more well-established shorter chain ligands, these long-chain NHCs are found to have characteristically large bite angles, which may be critical for enabling the deoxygenative arylation of aliphatic alcohols.

Effect of once-weekly exenatide on hospitalization for acute coronary syndrome or coronary revascularization in patients with type 2 diabetes mellitus.

Cardiovascular (CV) outcome studies of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have shifted the paradigm of type 2 diabetes management given their benefits regarding a reduction in major adverse CV events. However, the relationship between GLP-1 RAs and coronary revascularization remains poorly understood. In this EXSCEL post-hoc analysis, we used univariate Cox proportional models and Kaplan Meier survival analysis to evaluate the effect of once-weekly exenatide (EQW) on a composite outcome of hospitalization for acute coronary syndrome (ACS) or coronary revascularization. Similar models were utilized to evaluate the relationship between significant participant characteristics within the entire study population and the composite outcome. Of the 14,736 participants in EXSCEL with complete follow-up data, 1642 (11.1%) experienced an ACS or coronary revascularization event during a median follow-up of 3.3 years (interquartile range, 2.3-4.4). EQW had no effect on hospitalization for ACS or coronary revascularization (HR 1.00, 95% CI 0.91-1.10). Among EXSCEL participants, enrollment in Latin America (HR 0.51, 95% CI 0.43-0.60) and a history of peripheral artery disease (HR 0.79, 95% CI 0.70-0.90) were associated with a reduced risk for coronary revascularization, whereas enrollment in North America (HR 1.92, 95% CI 1.74-2.12), a history of CV disease (HR 3.24, 95% CI 2.78-3.78), and a previous myocardial infarction (HR 1.54, 95% CI 1.39-1.71) were associated with increased risk for study end points. EQW had no association with hospitalization for ACS or coronary revascularization. Participant enrollment location and CV disease burden may play a role in the variable CV efficacy of GLP-1 RAs that has been observed in trials thus far.

Inflammatory Serine Proteases Play a Critical Role in the Early Pathogenesis of Diabetic Cardiomyopathy.

BACKGROUND/AIMS: Diabetic cardiomyopathy (DCM) is characterized by structural and functional alterations that can lead to heart failure. Several mechanisms are known to be involved in the pathogenesis of DCM, however, the molecular mechanism that links inflammation to DCM is incompletely understood. To learn about this mechanism, we investigated the role of inflammatory serine proteases (ISPs) during the development of DCM. METHODS: Eight weeks old mice with deletion of dipeptidyl peptidase I (DPPI), an enzyme involved in the maturation of major ISPs, and wild type (WT) mice controls were injected with streptozotocin (50 mg/kg for 5 days intraperitoneally) and studied after 4, 8, 16, and 20 week after induction of type 1 diabetes mellitus (T1DM). Induction of diabetes was followed by echocardiographic measurements, glycemic and hemoglobulin A1c profiling, immunoblot, qPCR, enzyme activity assays, and immunohistochemistry (IHC) analysis of DPPI, ISPs, and inflammatory markers. Fibrosis was determined from left ventricular heart by Serius Red staining and qPCR. Apoptosis was determined by TUNEL assay and immunoblot analysis. RESULTS: In the diabetic WT mice, DPPI expression increased along with ISP activation, and DPPI accumulated abundantly in the left ventricle mainly from infiltrating neutrophils. In diabetic DPPI-knockout (DPPI-KO) mice, significantly decreased activation of ISPs, myocyte apoptosis, fibrosis, and cardiac function was improved compared to diabetic WT mice. In addition, DPPI-KO mice showed a decrease in overall inflammatory status mediated by diabetes induction which was manifested by decreased production of pro-inflammatory cytokines like TNF-α, IL-1ß and IL-6. CONCLUSION: This study elucidates a novel role of ISPs in potentiating the immunological responses that lead to the pathogenesis of DCM in T1DM. To the best of our knowledge, this is the first study to report that DPPI expression and activation promotes the inflammation that enhances myocyte apoptosis and contributes to the adverse cardiac remodeling that subsequently leads to DCM.

Alterations in microRNA expression in a murine model of diet-induced vasculogenic erectile dysfunction.

INTRODUCTION: MicroRNAs (miRs) are noncoding, endogenous RNA molecules that regulate gene expression and play roles in response to vascular injury. AIM: The aim of this study was to identify miRs expressed in corporal tissue (CT) and to determine whether miRs demonstrate differential expression in a mouse model of diet-induced erectile dysfunction (ED). METHODS: RNA was isolated from the CT from control mice and mice with diet-induced ED. A quantifiable miR profiling technique (NanoString) was used to determine the expression of over 600 miRs. MAIN OUTCOME MEASURES: Differential expression analysis was performed using a negative binomial regression model for count-based data. Mean expression levels, fold change, and false discovery-corrected P values were determined. Candidate miRs were validated via quantitative polymerase chain reaction (Q-PCR). RESULTS: In control mice, NanoString analysis revealed that 181 miRs were expressed above background levels and 5 miRs were expressed at high levels. Diet-induced ED resulted in the up-regulation of 6 miRs and the down-regulation of 65 miRs in the CT compared with mice on control diet. Focusing on the upregulated miRs, we chose five for Q-PCR validation. Of these five, two (miR-151-5p and miR-1937c) demonstrated significance via Q-PCR, whereas the other three (miR-720, miR-1937a, miR-205) trended in the correct direction. CONCLUSIONS: MiRs may play a significant role in mRNA regulation in CT and specific miRs may be involved in diet-induced vasculogenic ED. Future studies are aimed at determining the mRNA targets of these miRs.

Adenosine 2A receptor modulates inflammation and phenotype in experimental abdominal aortic aneurysms.

Activation of the adenosine 2A receptor (A2AR) reduces inflammation in models of acute injury but contribution in development of chronic abdominal aortic aneurysms (AAAs) is unknown. Elastase perfusion to induce AAA formation in A2AR-knockout (A2ARKO) and C57BL6/J wild-type (WT) mice resulted in nearly 100% larger aneurysms in A2ARKO compared to WT at d 14 (P<0.05), with evidence of greater elastin fragmentation, more immune cell infiltration, and increased matrix metallatoproteinase (MMP) 9 expression (P<0.05). Separately, exogenous A2AR antagonism in elastase-perfused WT mice also resulted in larger aneurysms (P<0.05), while A2AR agonism limited aortic dilatation (P<0.05). Activated Thy-1.2(+) T lymphocytes from WT mice treated in vitro with A2AR antagonist increased cytokine production, and treatment with A2AR agonist decreased cytokine production (P<0.05 for all). Primary activated CD4(+) T lymphocytes from A2ARKO mice exhibited greater chemotaxis (P<0.05). A2AR antagonist increased chemotaxis of activated CD4(+) cells from WT mice in vitro, and A2AR agonist reduced this effect (P<0.05). A2AR activation attenuates AAA formation partly by inhibiting immune cell recruitment and reducing elastin fragmentation. These findings support augmenting A2AR signaling as a putative target for limiting aneurysm formation.

Association of race and in-hospital outcomes following acute pulmonary embolism: A retrospective cohort study.

BACKGROUND: Racial disparities in health care are well established, with Black patients frequently experiencing the most significant consequences of this inequality. Acute pulmonary embolism (PE) is increasing in incidence and an important cause of morbidity and mortality in the United States, but little is known about racial disparities in the inpatient setting. HYPOTHESIS: Black and White patients admitted with acute PE will have different in-hospital outcomes. METHODS: All PE patients from January 1, 2016 to June 30, 2017 were retrospectively identified using ICD-10 codes. Data were abstracted by manual chart review for all image-confirmed PEs. RESULTS: A total of 782 patients with acute PE were identified, of which 319 (40.8%) were Black and 463 (59.2%) were White. Black patients had higher BMI (median [Q1-Q3]: 30.3 [25.4-36.6] vs. 29.3 [24.5-33.8] kg/m2 , p = .017), were younger (61 [48-74] vs. 67 [54-75] years, p = .001), and were more likely to have a history of heart failure (16.0 vs. 7.1%, p < .001), while White patients had higher rates of malignancy (46.9 vs. 34.5%, p = .001) and recent surgery (29.6 vs. 18.2%, p < .001). Black patients were more likely to receive systemic thrombolysis (3.1% vs. 1.1%, p = .040), while White patients had numerically higher rates of surgical embolectomy (0.3% vs. 1.1%, p = .41). No difference in inpatient mortality was observed; however, Black patients had longer hospital length of stay (5.0 [3-9] vs. 4.0 [2-9] days, p = .007) and were more likely to receive warfarin (23.5 vs. 12.1%, p < .001). CONCLUSIONS: Similar in-hospital mortality rates were observed in Black and White patients following acute PE. However, Black patients had longer hospital stays, higher warfarin prescription, and fewer traditional PE-related risk factors.

Racial Differences in Presentation and Outcomes After Peripheral Arterial Interventions: Insights From the NCDR-PVI Registry.

BACKGROUND: We assess the rates of device use and outcomes by race among patients undergoing lower extremity peripheral arterial intervention using the American College of Cardiology National Cardiovascular Data Registry-Peripheral Vascular Intervention (PVI) registry. METHODS: Patients who underwent PVI between April 2014 and March 2019 were included. Socioeconomic status was evaluated using the Distressed Community Index score for patients' zip codes. Multivariable logistic regression was used to assess factors associated with utilization of drug-eluting technologies, intravascular imaging, and atherectomy. Among patients with Centers for Medicare and Medicaid Services data, we compared 1-year mortality, rates of amputation, and repeat revascularizations. RESULTS: Of 63 150 study cases, 55 719 (88.2%) were performed in White patients and 7431 (11.8%) in Black patients. Black patients were younger (67.9 versus 70.0 years), had higher rates of hypertension (94.4% versus 89.5%), diabetes (63.0% versus 46.2%), less likely to be able to walk 200 m (29.1% versus 24.8%), and higher Distressed Community Index scores (65.1 versus 50.6). Black patients were provided drug-eluting technologies at a higher rate (adjusted odds ratio, 1.14 [95% CI, 1.06-1.23]) with no difference in atherectomy (adjusted odds ratio, 0.98 [95% CI, 0.91-1.05]) or intravascular imaging (adjusted odds ratio, 1.03 [95% CI, 0.88-1.22]) use. Black patients experienced a lower rate of acute kidney injury (adjusted odds ratio, 0.79 [95% CI, 0.72-0.88]). In Centers for Medicare and Medicaid Services-linked analyses of 7429 cases (11.8%), Black patients were significantly less likely to have surgical (adjusted hazard ratio, 0.40 [95% CI, 0.17-0.96]) or repeat PVI revascularization (adjusted hazard ratio, 0.42 [95% CI, 0.30-0.59]) at 1 year compared with White patients. There was no difference in mortality (adjusted hazard ratio [0.8-1.4]) or major amputation (adjusted hazard ratio, 2.5 [95% CI, 0.8-7.6]) between Black and White patients. CONCLUSIONS: Black patients presenting for PVI were younger, had higher prevalence of comorbidities and lower socioeconomic status. After adjustment, Black patients were less likely to have surgical or repeat PVI revascularization after the index PVI procedure.

Development of a novel murine model of aortic aneurysms using peri-adventitial elastase.

BACKGROUND: Our aim was to establish a novel model of abdominal aortic aneurysms (AAA) in mice using application of peri-adventitial elastase. METHODS: C57BL/6J male mice underwent infrarenal peri-adventitial application of either (1) sodium chloride (control; n = 7), (2) porcine pancreatic elastase (PPE; n = 14), or (3) PPE and doxycycline (PPE + doxycycline 200 mg/kg; n = 11) for 14 days. Aortas were analyzed by video micrometry, immunohistochemistry, qualitative polymerase chain reaction, and zymography. Groups underwent Mann-Whitney U comparisons. RESULTS: At day 14 compared with baseline, control animals had minimal aortic dilation, whereas fusiform aneurysms were seen in PPE (control, 20 ± 3%; PPE, 82 ± 15%; P ≤ .003). Doxycycline abrogated aneurysm formation (PPE, 82 ± 15%; PPE + doxycycline, 37 ± 10%; P ≤ .03). Compared with control and PPE + doxycycline, immunohistochemistry demonstrated greater elastin fiber degradation, macrophage infiltration, and matrix metalloproteinase-9 expression in PPE. Ki-67 and cleaved caspase-3 were lower in control versus PPE. The loss of smooth muscle marker expression seen with PPE was preserved in PPE + doxycycline. Zymography confirmed that both MMP-2 and -9 were more active in PPE than PPE + doxycycline. CONCLUSION: Peri-adventitial application of elastase is a simple, reproducible in vivo model of aneurysm formation leading to consistent infrarenal aortic aneurysm development by day 14, with inflammatory cell infiltration and MMP upregulation. Doxycycline inhibits AAA progression in this model via limiting matrix degradation and preserving differentiated smooth muscle cells.