Association of HIV Infection and Incident Abdominal Aortic Aneurysm Among 143 001 Veterans.

BACKGROUND: People with HIV (PWH) have an increased risk of cardiovascular disease. Previous cross-sectional data suggest there is a higher prevalence of abdominal aortic aneurysm (AAA) in PWH than in those without HIV. Whether PWH have an increased risk of incident AAA compared with those without HIV is unknown. METHODS: We analyzed data among participants without prevalent AAA from the Veterans Aging Cohort Study, a prospective, observational, longitudinal cohort of veterans with HIV matched 1:2 with veterans without HIV infection. We calculated AAA rates by HIV status and assessed the association between HIV infection and incident AAA using Cox proportional hazards models. We defined AAA using the International Classification of Diseases, 9th or 10th revision, or Current Procedural Terminology codes and adjusted all models for demographic characteristics, cardiovascular disease risk factors, and substance use. Secondary analyses examined the association between time-varying CD4+ T-cell count or HIV viral load and incident AAA. RESULTS: Among 143 001 participants (43 766 with HIV), over a median follow-up of 8.7 years, there were 2431 incident AAA events (26.4% among PWH). Rates of incident AAA per 1000 person-years were similar among PWH (2.0 [95% CI, 1.9-2.2]) and people without HIV (2.2 [95% CI, 2.1-2.3]). There was no evidence that HIV infection increased the risk of incident AAA compared with no HIV infection (adjusted hazard ratio, 1.02 [95% CI, 0.92-1.13]). In adjusted analyses with time-varying CD4+ T-cell counts or HIV viral load, PWH with CD4+ T-cell counts <200 cells/mm3 (adjusted hazard ratio, 1.29 [95% CI, 1.02-1.65]) or HIV viral load ≥500 copies/mL (adjusted hazard ratio, 1.29 [95% CI, 1.09-1.52]) had an increased risk of AAA compared with those without HIV. CONCLUSIONS: HIV infection is associated with an increased risk of AAA among those with low CD4+ T-cell counts or elevated HIV viral load over time.

Runx3 Regulates CD8+ T Cell Local Expansion and CD43 Glycosylation in Mice by H1N1 Influenza A Virus Infection.

We have recently reported that transcription factor Runx3 is required for pulmonary generation of CD8+ cytotoxic T lymphocytes (CTLs) that play a crucial role in the clearance of influenza A virus (IAV). To understand the underlying mechanisms, we determined the effects of Runx3 knockout (KO) on CD8+ T cell local expansion and phenotypes using an inducible general Runx3 KO mouse model. We found that in contrast to the lungs, Runx3 general KO promoted enlargement of lung-draining mediastinal lymph node (mLN) and enhanced CD8+ and CD4+ T cell expansion during H1N1 IAV infection. We further found that Runx3 deficiency greatly inhibited core 2 O-glycosylation of selectin ligand CD43 on activated CD8+ T cells but minimally affected the cell surface expression of CD43, activation markers (CD44 and CD69) and cell adhesion molecules (CD11a and CD54). Runx3 KO had a minor effect on lung effector CD8+ T cell death by IAV infection. Our findings indicate that Runx3 differently regulates CD8+ T cell expansion in mLNs and lungs by H1N1 IAV infection. Runx3 is required for CD43 core 2 O-glycosylation on activated CD8+ T cells, and the involved Runx3 signal pathway may mediate CD8+ T cell phenotype for pulmonary generation of CTLs.

Mitochondrial Acyl Carrier Protein of Leishmania major Displays Features Distinct from the Canonical Type II ACP.

Prokaryotes synthesize fatty acids using a type II synthesis pathway (FAS). In this process, the central player, i.e., the acyl carrier protein (ACP), sequesters the growing acyl chain in its internal hydrophobic cavity. As the acyl chain length increases, the cavity expands in size, which is reflected in the NMR chemical shift perturbations and crystal structures of the acyl-ACP intermediates. A few eukaryotic organelles, such as plastids and mitochondria, also harbor type II fatty acid synthesis machinery. Plastid FAS from spinach and Plasmodium falciparum has been characterized at the molecular level, but the mitochondrial pathway remains unexplored. Here, we report NMR studies of the mitochondrial acyl-acyl carrier protein intermediates of Leishmania major (acyl-LmACP). Our studies show that LmACP experiences remarkably small conformational changes upon acylation, with perturbations confined to helices II and III only. CastP determined that the cavity size of apo-LmACP (PDB entry 5ZWT) is less than that of Escherichia coli ACP (PDB 1T8K). Thus, the small chemical shift perturbations observed in the LmACP intermediates, coupled with CastP results, suggest an unusually small cavity when fully expanded. The faster rate of C8-LmACP chain hydrolysis compared to E. coli ACP (EcACP) also supports these convictions. Structure comparison of LmACP with other type II ACP disclosed unique differences in the helix I and loop I conformations, as well as several residues present there. Numerous hydrophobic residues in helix I and loop I (conserved in all mitochondrial ACPs) are substituted with hydrophilic residues in the bacterial/plastid type II ACP. For instance, Phe and leucine at positions 14 and 34 in LmACP are substituted with a hydrophilic residue and Ala in bacterial/plastid type II ACP. Mutation of Leu 34 to Ala (corresponding residue in EcACP) resulted in a complete loss of structure, underscoring its importance in maintaining the ACP fold. Thus, our NMR studies, combined with insights from the crystal structure, highlight several unique features of LmACP, distinct from the prokaryote and plastid type II ACP. Given the high sequence identity, the features might be conserved in all mitochondrial ACPs.

Lipoate protein ligase B primarily recognizes the C8-phosphopantetheine arm of its donor substrate and weakly binds the acyl carrier protein.

Lipoic acid is a sulfur-containing cofactor indispensable for the function of several metabolic enzymes. In microorganisms, lipoic acid can be salvaged from the surroundings by lipoate protein ligase A (LplA), an ATP-dependent enzyme. Alternatively, it can be synthesized by the sequential actions of lipoate protein ligase B (LipB) and lipoyl synthase (LipA). LipB takes up the octanoyl chain from C8-acyl carrier protein (C8-ACP), a byproduct of the type II fatty acid synthesis pathway, and transfers it to a conserved lysine of the lipoyl domain of a dehydrogenase. However, the molecular basis of its substrate recognition is still not fully understood. Using Escherichia coli LipB as a model enzyme, we show here that the octanoyl-transferase mainly recognizes the 4'-phosphopantetheine-tethered acyl-chain of its donor substrate and weakly binds the apo-acyl carrier protein. We demonstrate LipB can accept octanoate from its own ACP and noncognate ACPs, as well as C8-CoA. Furthermore, our 1H saturation transfer difference and 31P NMR studies demonstrate the binding of adenosine, as well as the phosphopantetheine arm of CoA to LipB, akin to binding to LplA. Finally, we show a conserved 71RGG73 loop, analogous to the lipoate-binding loop of LplA, is required for full LipB activity. Collectively, our studies highlight commonalities between LipB and LplA in their mechanism of substrate recognition. This knowledge could be of significance in the treatment of mitochondrial fatty acid synthesis related disorders.

Associations of HIV and Depression with Incident Diabetes Mellitus: Veterans Aging Cohort Study.

BACKGROUND: Persons with HIV (PWH) are at increasingly higher risk for metabolic complications, including diabetes mellitus (DM). Additionally, depression is highly prevalent among PWH and has been associated with increased risk for DM in the general population. However, the association of HIV and depression with incident DM has not been well established. METHODS: Using the Veterans Aging Cohort Study (VACS), we selected adults with and without HIV who did not have DM at baseline. Prevalent depression was defined as having a Patient Health Questionnaire-9 (PHQ-9) score of ≥10. Incident DM was identified using validated Kelly's criteria. Basic clinical and demographic characteristics were collected, and cox proportional hazards regression models were run to test the association between depression and incident DM stratified by HIV serostatus. RESULTS: A total of 5,722 participants were analyzed, 2,886 (53%) had HIV and 1,124 (20%) had depression at baseline. 1,235 (22%) participants developed incident DM during follow-up, with 26% of HIV-negative participants developing DM compared to 17% of participants with HIV. Depression was significantly associated with increased risk of incident DM among HIV-negative participants (adjusted HR [aHR] = 1.31; p-value 0.003), but not among participants with HIV (aHR 1.09; p-value 0.44). However, among participants with HIV with baseline viral load < 500 copies/mL, we noted a stronger association between depression and incident DM. CONCLUSIONS: Incident DM in the VACS cohort is significantly higher for HIV-negative participants compared to veterans with HIV. A significant association between depression and incident DM was noted among HIV-negative participants but not among those with HIV.

Therapeutic enzymes as non-conventional targets in cardiovascular impairments: A comprehensive review.

Over the last few decades, substantial progress has been made towards the understanding of cardiovascular diseases. In-depth mechanistic insights have also provided opportunities to explore novel therapeutic targets and to discover new treatment regimens. Therapeutic enzymes are examples of such opportunities. The enzymes protect against a variety of cardiovascular diseases, however, even minor malfunctioning of these enzymes may lead to deleterious outcomes. Owing to their great versatility, the inhibition and activation of these enzymes are key regulatory approaches to counter the onset and progression of several cardiovascular impairments. While cardiovascular remedies are already available in excess and are efficacious, a comprehensive description of novel therapeutic enzymes to combat cardiovascular diseases would still be of great benefit. In the light of this, the regulation of functional activities of these enzymes also opens a new avenue for the treatment approaches to be employed. This review describes the importance of non-conventional enzymes such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX), phosphodiesterase (PDE), arginase, superoxide dismutase (SOD), thioredoxin reductase (TXNRD) and selenoprotein T (SELENOT), cytochrome b5 reductase 3 (CYB5R3), epoxide hydrolase (EHs), xanthine oxidoreductase (XOR), matrix metalloprotease (MMPs), and dopamine beta hydroxylase (DBH), as potential candidates in several cardiovascular disorders while highlighting some of the recently targeted therapeutic enzymes in cardiovascular diseases. We also discuss the role of intrinsic antioxidant defense system involved in cardioprotection followed by addressing some of the clinical investigations considering the use of antioxidant as a preferred therapy of cardiovascular complications.

Optimization and Identification of Single Mutation in Hemoglobin Variants with 2,2,2 Trifluoroethanol Modified Digestion Method and Nano-LC Coupled MALDI MS/MS.

Background: Hemoglobin (Hb) variants arise due to point mutations in globin chains and their pathological treatments rely heavily on the identification of the nature and location of the mutation in the globin chains. Traditional methods for diagnosis such as HPLC and electrophoresis have their own limitations. Therefore, the present study aims to develop and optimize a specific method of sample processing that could lead to improved sequence coverage and analysis of Hb variants by nano LC-MALDI MS/MS. Methods: In our study, we primarily standardized various sample processing methods such as conventional digestion with trypsin followed by 10% acetonitrile treatment, digestion with multiple proteases like trypsin, Glu-C, Lys-C, and trypsin digestion subsequent to 2,2,2 trifluoroethanol (TFE) treatment. Finally, the peptides were identified by LC-MALDI MS/MS. All of these sample processing steps were primarily tested with recombinant Hb samples. After initial optimization, we found that the TFE method was the most suitable one and the efficiency of this method was applied in Hb variant identification based on high sequence coverage. Results: We developed and optimized a method using an organic solvent TFE and heat denaturation prior to digestion, resulting in 100% sequence coverage in the ß-chains and 95% sequence coverage in the α-chains, which further helped in the identification of Hb mutations. A Hb variant protein sequence database was created to specify the search and reduce the search time. Conclusion: All of the mutations were identified using a bottom-up non-target approach. Therefore, a sensitive, robust and reproducible method was developed to identify single substitution mutations in the Hb variants from the sequence of the entire globin chains. Biological Significance: Over 330,000 infants are born annually with hemoglobinopathies and it is the major cause of morbidity and mortality in early childhood. Hb variants generally arise due to point mutation in the globin chains. There is high sequence homology between normal Hb and Hb variant chains. Due to this high homology between the two forms, identification of variants by mass spectrometry is very difficult and requires the full sequence coverage of α- and ß-chains. As such, there is a need for a suitable method that provides 100% sequence coverage of globin chains for variant analysis by mass spectrometry. Our study provides a simple, robust, and reproducible method that is suitable for LC-MALDI and provides nearly complete sequence coverage in the globin chains. This method may be used in the near future in routine diagnosis for Hb variant analysis.

A mechanism for hereditary angioedema with normal C1 inhibitor: an inhibitory regulatory role for the factor XII heavy chain.

The plasma proteins factor XII (FXII) and prekallikrein (PK) undergo reciprocal activation to the proteases FXIIa and kallikrein by a process that is enhanced by surfaces (contact activation) and regulated by the serpin C1 inhibitor. Kallikrein cleaves high-molecular-weight kininogen (HK), releasing the vasoactive peptide bradykinin. Patients with hereditary angioedema (HAE) experience episodes of soft tissue swelling as a consequence of unregulated kallikrein activity or increased prekallikrein activation. Although most HAE cases are caused by reduced plasma C1-inhibitor activity, HAE has been linked to lysine/arginine substitutions for Thr309 in FXII (FXII-Lys/Arg309). Here, we show that FXII-Lys/Arg309 is susceptible to cleavage after residue 309 by coagulation proteases (thrombin and FXIa), resulting in generation of a truncated form of FXII (δFXII). The catalytic efficiency of δFXII activation by kallikrein is 15-fold greater than for full-length FXII. The enhanced rate of reciprocal activation of PK and δFXII in human plasma and in mice appears to overwhelm the normal inhibitory function of C1 inhibitor, leading to increased HK cleavage. In mice given human FXII-Lys/Arg309, induction of thrombin generation by infusion of tissue factor results in enhanced HK cleavage as a consequence of δFXII formation. The effects of δFXII in vitro and in vivo are reproduced when wild-type FXII is bound by an antibody to the FXII heavy chain (HC; 15H8). The results contribute to our understanding of the predisposition of patients carrying FXII-Lys/Arg309 to angioedema after trauma, and reveal a regulatory function for the FXII HC that normally limits PK activation in plasma.

Advances in mass spectrometric methods for detection of hemoglobin disorders.

Hemoglobin disorders are caused due to alterations in the hemoglobin molecules. These disorders are categorized in two broad classes - hemoglobin variants and thalassemias. The hemoglobin variants arise due to point mutations in the alpha (α), beta (ß), gamma (γ), delta (δ), or epsilon (ε) globin chains of these proteins, while thalassemias are caused due to the under-production of α or ß globin chain. Hemoglobin disorders account for 7 % of the major health issues globally. Mass Spectrometry is an extensively used analytical tool in the field of protein identification, protein-protein interaction, biomarker discovery and diagnosis of several impairments including hemoglobin related disorders. The remarkable advancements in the technology and method development have enormously augmented the clinical significance of mass spectrometry in these fields. The present review describes hemoglobin disorders and the recent advancements in mass spectrometry in the detection of such disorders, including its advantages, lacunae, and future directions. The literature evidence concludes that mass spectrometry can be potentially used as a 'First Line Screening Assay' for the detection of hemoglobin disorders in the near future.

Association of Syndemic Unhealthy Alcohol Use, Smoking, and Depressive Symptoms on Incident Cardiovascular Disease among Veterans With and Without HIV-Infection.

Unhealthy alcohol use, smoking, and depressive symptoms are risk factors for cardiovascular disease (CVD). Little is known about their co-occurrence - termed a syndemic, defined as the synergistic effect of two or more conditions-on CVD risk in people with HIV (PWH). We used data from 5621 CVD-free participants (51% PWH) in the Veteran's Aging Cohort Study-8, a prospective, observational study of veterans followed from 2002 to 2014 to assess the association between this syndemic and incident CVD by HIV status. Diagnostic codes identified cases of CVD (acute myocardial infarction, stroke, heart failure, peripheral artery disease, and coronary revascularization). Validated measures of alcohol use, smoking, and depressive symptoms were used. Baseline number of syndemic conditions was categorized (0, 1, ≥ 2 conditions). Multivariable Cox Proportional Hazards regressions estimated risk of the syndemic (≥ 2 conditions) on incident CVD by HIV-status. There were 1149 cases of incident CVD (52% PWH) during the follow-up (median 10.1 years). Of the total sample, 64% met our syndemic definition. The syndemic was associated with greater risk for incident CVD among PWH (Hazard Ratio [HR] 1.87 [1.47-2.38], p < 0.001) and HIV-negative veterans (HR 1.70 [1.35-2.13], p < 0.001), compared to HIV-negative with zero conditions. Among those with the syndemic, CVD risk was not statistically significantly higher among PWH vs. HIV-negative (HR 1.10 [0.89, 1.37], p = .38). Given the high prevalence of this syndemic combined with excess risk of CVD, these findings support linked-screening and treatment efforts.

Associations of Total, Cognitive/Affective, and Somatic Depressive Symptoms and Antidepressant Use With Cardiovascular Disease-Relevant Biomarkers in HIV: Veterans Aging Cohort Study.

OBJECTIVE: We sought to determine the associations of total, cognitive/affective, and somatic depressive symptoms and antidepressant use with biomarkers of processes implicated in cardiovascular disease in HIV (HIV-CVD). METHODS: We examined data from 1546 HIV-positive and 843 HIV-negative veterans. Depressive symptoms were assessed using the Patient Health Questionnaire-9, and past-year antidepressant use was determined from Veterans Affair pharmacy records. Monocyte (soluble CD14 [sCD14]), inflammatory (interleukin-6 [IL-6]), and coagulation (D-dimer) marker levels were determined from previously banked blood specimens. Linear regression models with multiple imputation were run to estimate the associations between depression-related factors and CVD-relevant biomarkers. RESULTS: Among HIV-positive participants, greater somatic depressive symptoms were associated with higher sCD14 (exp[b] = 1.02, 95% confidence interval [CI] = 1.00-1.03) and D-dimer (exp[b] = 1.06, 95% CI = 1.00-1.11) after adjustment for demographics and potential confounders. Further adjustment for antidepressant use and HIV factors slightly attenuated these relationships. Associations were also detected for antidepressant use, as selective serotonin reuptake inhibitor use was related to lower sCD14 (exp[b] = 0.95, 95% CI = 0.91-1.00) and IL-6 (exp[b] = 0.86, 95% CI = 0.76-0.96), and tricyclic antidepressant use was related to higher sCD14 (exp[b] = 1.07, 95% CI = 1.03-1.12) and IL-6 (exp[b] = 1.14, 95% CI = 1.02-1.28). Among HIV-negative participants, total, cognitive/affective, and somatic depressive symptoms were associated with higher IL-6, and tricyclic antidepressant use was related to higher sCD14. CONCLUSIONS: Our novel findings suggest that a) monocyte activation and altered coagulation may represent two pathways through which depression increases HIV-CVD risk and that b) tricyclic antidepressants may elevate and selective serotonin reuptake inhibitors may attenuate HIV-CVD risk by influencing monocyte and inflammatory activation.

Predictive Accuracy of a Polygenic Risk Score Compared With a Clinical Risk Score for Incident Coronary Heart Disease.

Importance: Polygenic risk scores comprising millions of single-nucleotide polymorphisms (SNPs) could be useful for population-wide coronary heart disease (CHD) screening. Objective: To determine whether a polygenic risk score improves prediction of CHD compared with a guideline-recommended clinical risk equation. Design, Setting, and Participants: A retrospective cohort study of the predictive accuracy of a previously validated polygenic risk score was assessed among 4847 adults of white European ancestry, aged 45 through 79 years, participating in the Atherosclerosis Risk in Communities (ARIC) study and 2390 participating in the Multi-Ethnic Study of Atherosclerosis (MESA) from 1996 through December 31, 2015, the final day of follow-up. The performance of the polygenic risk score was compared with that of the 2013 American College of Cardiology and American Heart Association pooled cohort equations. Exposures: Genetic risk was computed for each participant by summing the product of the weights and allele dosage across 6 630 149 SNPs. Weights were based on an international genome-wide association study. Main Outcomes and Measures: Prediction of 10-year first CHD events (including myocardial infarctions, fatal coronary events, silent infarctions, revascularization procedures, or resuscitated cardiac arrest) assessed using measures of model discrimination, calibration, and net reclassification improvement (NRI). Results: The study population included 4847 adults from the ARIC study (mean [SD] age, 62.9 [5.6] years; 56.4% women) and 2390 adults from the MESA cohort (mean [SD] age, 61.8 [9.6] years; 52.2% women). Incident CHD events occurred in 696 participants (14.4%) and 227 participants (9.5%), respectively, over median follow-up of 15.5 years (interquartile range [IQR], 6.3 years) and 14.2 (IQR, 2.5 years) years. The polygenic risk score was significantly associated with 10-year CHD incidence in ARIC with hazard ratios per SD increment of 1.24 (95% CI, 1.15 to 1.34) and in MESA, 1.38 (95% CI, 1.21 to 1.58). Addition of the polygenic risk score to the pooled cohort equations did not significantly increase the C statistic in either cohort (ARIC, change in C statistic, -0.001; 95% CI, -0.009 to 0.006; MESA, 0.021; 95% CI, -0.0004 to 0.043). At the 10-year risk threshold of 7.5%, the addition of the polygenic risk score to the pooled cohort equations did not provide significant improvement in reclassification in either ARIC (NRI, 0.018, 95% CI, -0.012 to 0.036) or MESA (NRI, 0.001, 95% CI, -0.038 to 0.076). The polygenic risk score did not significantly improve calibration in either cohort. Conclusions and Relevance: In this analysis of 2 cohorts of US adults, the polygenic risk score was associated with incident coronary heart disease events but did not significantly improve discrimination, calibration, or risk reclassification compared with conventional predictors. These findings suggest that a polygenic risk score may not enhance risk prediction in a general, white middle-aged population.

Regulation of monoamine oxidase A (MAO-A) expression, activity, and function in IL-13-stimulated monocytes and A549 lung carcinoma cells.

Monoamine oxidase A (MAO-A) is a mitochondrial flavoenzyme implicated in the pathogenesis of atherosclerosis and inflammation and also in many neurological disorders. MAO-A also has been reported as a potential therapeutic target in prostate cancer. However, the regulatory mechanisms controlling cytokine-induced MAO-A expression in immune or cancer cells remain to be identified. Here, we show that MAO-A expression is co-induced with 15-lipoxygenase (15-LO) in interleukin 13 (IL-13)-activated primary human monocytes and A549 non-small cell lung carcinoma cells. We present evidence that MAO-A gene expression and activity are regulated by signal transducer and activator of transcription 1, 3, and 6 (STAT1, STAT3, and STAT6), early growth response 1 (EGR1), and cAMP-responsive element-binding protein (CREB), the same transcription factors that control IL-13-dependent 15-LO expression. We further established that in both primary monocytes and in A549 cells, IL-13-stimulated MAO-A expression, activity, and function are directly governed by 15-LO. In contrast, IL-13-driven expression and activity of MAO-A was 15-LO-independent in U937 promonocytic cells. Furthermore, we demonstrate that the 15-LO-dependent transcriptional regulation of MAO-A in response to IL-13 stimulation in monocytes and in A549 cells is mediated by peroxisome proliferator-activated receptor γ (PPARγ) and that signal transducer and activator of transcription 6 (STAT6) plays a crucial role in facilitating the transcriptional activity of PPARγ. We further report that the IL-13-STAT6-15-LO-PPARγ axis is critical for MAO-A expression, activity, and function, including migration and reactive oxygen species generation. Altogether, these results have major implications for the resolution of inflammation and indicate that MAO-A may promote metastatic potential in lung cancer cells.

A Diruthenium Complex of an N-Pyridyl-o-aminophenol Derivative: A Route to Mixed Valency.

An N-pyridyl-o-aminophenol derivative that stabilises mixed-valence states of ruthenium ions is disclosed. A diruthenium complex, [(LIQ 0 )Ru2 Cl5 ]⋅MeOH (1⋅MeOH) is successfully isolated, in which LIQ 0 is the o-iminobenzoquinone form of 2-[(3-nitropyridin-2-yl)amino]phenol (LAP H2 ). In 1, LIQ 0 oriented towards one ruthenium centre is a non-innocent NO-donor redox ligand, whereas another oriented towards another ruthenium centre is an innocent pyridine-donor redox ligand. Complex 1 is a diruthenium(II,III) mixed-valence complex, [RuII (LIQ 0 )(µ-Cl)2 RuIII ], with a minor contribution from the diruthenium(III,III) state. [RuIII (LISQ .- )(µ-Cl)2 RuIII ] contains LISQ .- , which is the o-iminobenzosemiquinonate anion radical form of the ligand. Complexes 1- and 1+ are diruthenium(II,II), [RuII (LIQ 0 )(µ-Cl)2 RuII ], and diruthenium(III,III), [RuIII (LIQ 0 )(µ-Cl)2 RuIII ], complexes, respectively, of LIQ 0 . Complex 12- is a diruthenium(II,II) complex of the o-iminobenzosemiquinonate anion radical (LISQ .- ), [RuII (LISQ .- )(µ-Cl)2 RuII ], with a minor contribution from the diruthenium(III,II) form, [RuIII (LAP 2- )(µ-Cl)2 RuII ]. Complex 12+ is a diruthenium(III,IV) mixed-valence complex of LIQ 0 , [RuIII (LIQ 0 )(µ-Cl)2 RuIV ]. Complexes 1 and 12+ exhibit inter-valence charge-transfer transitions at λ=1300 and 1370 nm, respectively.

Association of Smoking Cessation With Subsequent Risk of Cardiovascular Disease.

Importance: The time course of cardiovascular disease (CVD) risk after smoking cessation is unclear. Risk calculators consider former smokers to be at risk for only 5 years. Objective: To evaluate the association between years since quitting smoking and incident CVD. Design, Setting, and Participants: Retrospective analysis of prospectively collected data from Framingham Heart Study participants without baseline CVD (original cohort: attending their fourth examination in 1954-1958; offspring cohort: attending their first examination in 1971-1975) who were followed up through December 2015. Exposures: Time-updated self-reported smoking status, years since quitting, and cumulative pack-years. Main Outcomes and Measures: Incident CVD (myocardial infarction, stroke, heart failure, or cardiovascular death). Primary analyses included both cohorts (pooled) and were restricted to heavy ever smokers (≥20 pack-years). Results: The study population included 8770 individuals (original cohort: n = 3805; offspring cohort: n = 4965) with a mean age of 42.2 (SD, 11.8) years and 45% male. There were 5308 ever smokers with a median 17.2 (interquartile range, 7-30) baseline pack-years, including 2371 heavy ever smokers (406 [17%] former and 1965 [83%] current). Over 26.4 median follow-up years, 2435 first CVD events occurred (original cohort: n = 1612 [n = 665 among heavy smokers]; offspring cohort: n = 823 [n = 430 among heavy smokers]). In the pooled cohort, compared with current smoking, quitting within 5 years was associated with significantly lower rates of incident CVD (incidence rates per 1000 person-years: current smoking, 11.56 [95% CI, 10.30-12.98]; quitting within 5 years, 6.94 [95% CI, 5.61-8.59]; difference, -4.51 [95% CI, -5.90 to -2.77]) and lower risk of incident CVD (hazard ratio, 0.61; 95% CI, 0.49-0.76). Compared with never smoking, quitting smoking ceased to be significantly associated with greater CVD risk between 10 and 15 years after cessation in the pooled cohort (incidence rates per 1000 person-years: never smoking, 5.09 [95% CI, 4.52-5.74]; quitting within 10 to <15 years, 6.31 [95% CI, 4.93-8.09]; difference, 1.27 [95% CI, -0.10 to 3.05]; hazard ratio, 1.25 [95% CI, 0.98-1.60]). Conclusions and Relevance: Among heavy smokers, smoking cessation was associated with significantly lower risk of CVD within 5 years relative to current smokers. However, relative to never smokers, former smokers' CVD risk remained significantly elevated beyond 5 years after smoking cessation.

The "Recognition Helix" of the Type II Acyl Carrier Protein (ACP) Utilizes a "Ubiquitin Interacting Motif (UIM)"-like Surface To Bind Its Partners.

Interaction interfaces comprise a finite number of sequence/structural motifs, which are often repeated in nature. Here we show how a helical motif present in the acyl carrier protein (ACP), involved in multiprotein interactions, displays a binding interface similar to that of the "ubiquitin interacting motif (UIM)". Analysis of the crystal structures of the ACP-enzyme complexes gave the first hint that helix II of the ACP ("universal recognition helix") utilizes UIM-like noncovalent interactions to associate with the type II fatty acid biosynthesis (FAS) pathway enzymes. The ACP interacting functional surface of the FAS enzymes comprises positively charged residues, flanking a central hydrophobic patch, akin to ubiquitin. Our nuclear magnetic resonance chemical shift perturbation studies, relaxation studies, and surface plasmon resonance measurements unequivocally show that helix II of ACP behaves like a UIM motif in its interactions with ubiquitin, by binding the Ile 44 functional surface of the latter. A synthetic peptide with the ACP helix II sequence showed equivalent binding to ubiquitin. The evolution of similar interaction motifs in the two systems has probably been driven by functional constraints, as both ACP and UIM participate in multiprotein interactions.

Activation of D2 Dopamine Receptors in CD133+ve Cancer Stem Cells in Non-small Cell Lung Carcinoma Inhibits Proliferation, Clonogenic Ability, and Invasiveness of These Cells.

Lung carcinoma is the leading cause of cancer-related death worldwide, and among this cancer, non-small cell lung carcinoma (NSCLC) comprises the majority of cases. Furthermore, recurrence and metastasis of NSCLC correlate well with CD133+ve tumor cells, a small population of tumor cells that have been designated as cancer stem cells (CSC). We have demonstrated for the first time high expression of D2 dopamine (DA) receptors in CD133+ve adenocarcinoma NSCLC cells. Also, activation of D2 DA receptors in these cells significantly inhibited their proliferation, clonogenic ability, and invasiveness by suppressing extracellular signal-regulated kinases 1/2 (ERK1/2) and AKT, as well as down-regulation of octamer-binding transcription factor 4 (Oct-4) expression and matrix metalloproteinase-9 (MMP-9) secretion by these cells. These results are of significance as D2 DA agonists that are already in clinical use for treatment of other diseases may be useful in combination with conventional chemotherapy and radiotherapy for better management of NSCLC patients by targeting both tumor cells and stem cell compartments in the tumor mass.

Rice phytoglobins regulate responses under low mineral nutrients and abiotic stresses in Arabidopsis thaliana.

Just like animals, plants also contain haemoglobins (known as phytoglobins in plants). Plant phytoglobins (Pgbs) have been categorized into 6 different classes, namely, Phytogb0 (Pgb0), Phytogb1 (Pgb1), Phytogb2 (Pgb2), SymPhytogb (sPgb), Leghaemoglobin (Lb), and Phytogb3 (Pgb3). Among the 6 Phytogbs, sPgb and Lb have been functionally characterized, whereas understanding of the roles of other Pgbs is still evolving. In our present study, we have explored the function of 2 rice Pgbs (OsPgb1.1 and OsPgb1.2). OsPgb1.1, OsPgb1.2, OsPgb1.3, and OsPgb1.4 displayed increased level of transcript upon salt, drought, cold, and ABA treatment. The overexpression (OX) lines of OsPgb1.2 in Arabidopsis showed a tolerant phenotype in terms of better root growth in low potassium (K+ ) conditions. The expression of the known K+ gene markers such as LOX2, HAK5, and CAX3 was much higher in the OsPgb1.2 OX as compared to wild type. Furthermore, the OsPgb1.2 OX lines showed a decrease in reactive oxygen species (ROS) production and conversely an increase in the K+ content, both in root and shoot, as compared to wild type in K+ limiting condition. Our results indicated the potential involvement of OsPgb1.2 in signalling networks triggered by the nutrient deficiency stresses.

Proton-Coupled Oxidation of a Diarylamine: Amido and Aminyl Radical Complexes of Ruthenium(II).

Diarylamido, Q-N--Py (L-), complexes of ruthenium(II), trans-[(L-H+)RuII(PPh3)2Cl2] (1-H+) and trans-[(L-)RuII(PPh3)2(CO)Cl] (2), using N-(5-nitropyridin-2-yl)quinolin-8-amine (HL) as a ligand are disclosed (Q and Py refer to quinoline and 5-nitropyridine fragments). 1-H+ contains a zwitterionic amido ligand (Q-N--PyH+) that undergoes a concerted proton electron transfer (CPET) reaction in air, generating trans-[(L)Ru(PPh3)2Cl2] (1·CH2Cl2). The ground electronic state of 1 is delocalized as [(L-)RuIII ↔ (L•)RuII] (L• is an aminyl radical of type Q-N•-Py). The 1-H+/1 redox potential depends on the electrolytes, and the potentials are -1.57 and -1.40 V, respectively, in the presence of [N( n-Bu)4]PF6 and [N( n-Bu)4]Cl. The rate of 1-H+ → 1 conversion depends also on the medium and follows the order kD2O-CH2Cl2 > kH2O-CH2Cl2 > kCH2Cl2. In contrast, 2 containing the corresponding amido (L-) is stable and endures oxidation at 0.14 V, affording trans-[(L•)RuII(PPh3)2(CO)Cl] (2+). The electronic structures of the complexes were authenticated by single-crystal X-ray diffraction studies of HL, 1·CH2Cl2, and 2·(toluene), EPR spectroscopy, and density functional theory (DFT) calculations. Notably, the CQ-N (1.401(2) Å) and CPy-N (1.394(2) Å) lengths in 1·CH2Cl2 are relatively longer than the CQ-Namido (1.396(4) Å)and CPy-Namido (1.372(4) Å) lengths in 2·(toluene). Spin density obtained from DFT calculations scatters on both N and ruthenium atoms, revealing a delocalized state of 1. The notion was further confirmed by variable-temperature EPR spectra of a powder sample and CH2Cl2 solution, where the contributions of both [(L-)RuIII] and [(L•)RuII] components were detected. In contrast, 2+ is an aminyl radical complex of ruthenium(II), where the spin is dominantly localized on the ligand backbone (64%), particularly on N (27%). 2+ exhibits a strong EPR signal at g = 2.003. 1 and 2+ exhibit absorption bands at 560-630 and 830-840 nm, and the origins of these excitations were elucidated by TDDFT calculations on 1 and 2 in CH2Cl2.