Evaluation of an in-house IgM/IgG lateral flow assay for serodiagnosis of human brucellosis

This study aimed to evaluate the diagnostic efficacy of an in-house lateral flow assay (LFA) for the detection of IgM/IgG anti-Brucella antibodies for rapid serodiagnosis of human brucellosis. Three groups of sera samples including 476 from high-risk individuals, 27 from culture-confirmed patients, and 43 from healthy blood donors were used for evaluation of LFA. In comparison with iELISA, the sensitivity, specificity, and accuracy of LFA were >95%, >99%, and 99% respectively. Considering the very good agreement, accuracy, simplicity, and rapidity, LFAs might be useful as a point of care test for the diagnosis of human brucellosis in resource-limited laboratories.

Inhibitory effect of Salvia coccinea on inflammatory responses through NF-κB signaling pathways in THP-1 cells and acute rat diabetes mellitus

Hyperglycemia-induced oxidative stress has been implicated in diabetes and its complications. Medicinal plants possessing antioxidant activity may decrease oxidative stress by scavenging radicals and reducing power activity and would be a promising strategy for the treatment of inflammatory disorders like diabetes. This study was designed to evaluate the antioxidant effect of Aqueous Extract of  S.coccinea leaf (AESL) in HG treated THP-1 cells and streptozotocin (STZ)-induced diabetic Wistar rats. AESL and the standard antidiabetic drug glibenclamide were administered orally by intragastric tube for 14 days and pre-treated HG grown THP-1 cells. AESL treatment reduced HG induced increase in ROS production, NF-κB dependent proinflammatory gene expression by influencing NF-κB nuclear translocation in THP-1 cells. Oral administration of AESL inhibited STZ-induced increase in serum lipid peroxidation, aspartate transaminase, alanine transaminase, and Lactate dehydrogenase of diabetic rats. Significant increase in activity of superoxide dismutase, catalase and glutathione peroxidase, and a reduced level of glutathione, were observed in AESL treatment. The results demonstrate that AESL is useful in controlling blood glucose and also has antioxidant potential to influence the translocation of NF-κB, protect damage caused by hyperglycemia-induced inflammation.

Abstract 539: Buthionine Sulfoximine (BSO) Prevents Reductive Stress-induced Pathological Hypertrophic Cardiomyopathy

Background: Chronic reductive stress (RS) induces pathological cardiac remodeling and diastolic dysfunction. Here, we hypothesized that preventing RS via glutathione (GSH) depletion, through selective inhibition of γ-glutamyl cysteine ligase (γGCL), mitigates cardiac pathology in cRS mice.

Methods: Cardiac-specific constitutively active Nrf2 TG-mice (α-MHc-caNrf2-TG), at 6 weeks of age, were administered with buthionine sulfoximine (BSO; 5.0 mM/Kg; daily for 16-weeks). At the end of 22 weeks, cardiac structure and function (systole & diastole using echocardiography), myocardial redox state, levels of ROS (using dihydroethidium (DHE) fluorescence), and antioxidant proteome were assessed in TG mice treated with PBS or BSO and compared with the age matched NTG littermates (n=6/group).

Results: While the TG mice experiencing RS (GSH; 426.3±22.55 vs. 141.8±3.9 & GSH/GSSG; 61.04±5.4 vs. 23.27±1.3 in TG vs. NTG), this was significantly curtailed in BSO-treated TG mice (GSH 161.8±12.6 & GSH/GSSG; 25.1±4.3). This was coupled with the normal cardiac functions (EF; ~53% & MV E/A; 1.57) in the BSO-treated TG when compared to TG mice experiencing a hyper systolic function (>80% ejection fraction) with decreased cardiac volume and diastolic dysfunction with restricted filling (MV E/A ratio; >3.0), Of note, BSO treatment did not alter the protein levels of antioxidants (i.e. GCLC, GCLM, NQO1 and CAT), but only depleted the GSH pool (via inhibiting GCL activity) and restored the basal ROS signaling in the myocardium. Moreover, the BSO-treated TG mice did not develop cardiac hypertrophy, which was assessed by heart weight/body weight ratio, qPCR-based gene expression for hypertrophy ( Anf, Bnf, α-MHc and β-Mhc ).

Conclusion: Our results suggest that pharmacological manipulation of myocardial redox and repletion of basal ROS signaling prevented RS-mediated pathological processes and rescued the cardiac structure and function.

Abstract 551: Distinct Transcriptional Roles for Wildtype vs. Truncated Nrf2 in the Heart of Transgenic Mice

Background: Nuclear erythroid-2 like factor-2 (Nrf2), a redox-sensitive transcriptional regulator of cytoprotective and antioxidant genes. Despite the basal transcription of antioxidants/redox genes, forced activation of Nrf2 may lead to “reductive stress” (RS). In this study, we hypothesized that controlled vs. sustained activation of Nrf2 differentially regulates the myocardial transcriptome, which elucidates the transition of a physiological adaptation to pathological process.

Methods: Cardiac specific Nrf2 transgenic mice expressing full length Nrf2 (FL-TG) and truncated Nrf2 (TR-TG), and their non-transgenic littermates (NTG) in the C57/BL6J backround at the age of 6-8 months were used for this study. Next generation RNA sequencing was performed using the myocardial mRNA obtained from FL-TG, TR-TG and NTG mice (n=3/group). Validation of the NGS data was carried out by qPCR analysis using specific primers for the targeted genes(n=4 to 6/group).

Results: Analysis of the NGS data uncovered eccentric genomic profiles in the myocardium of mice with a 310 differentially regulated genes (DEGs) in FL-TG ( vs. NTG) and 472 DEGs in TR-TG ( vs. NTG). A closer evaluation reveals 397 and 237 DEGs commonly shared between FL-TG and TR-TG, respectively. STRING analysis revealed genomic networks involve in oxidoreductase, antioxidant and glutathione transferase were differentially altered between TL-TG vs. TR-TG groups. For instance, within the glutathione synthesis pathway, Gclm transcript was upregulated 6.0 fold (FL-TG) and 8.0 fold (TR-TG) when compared to NTG. Indeed, a significant douwnregulation of stress response genes Hspa1b (5.0 & 2.0 fold) and Hsph1 (2.0 & 2.2 fold) was apparent in between the groups. An eccentric cytoskeletal disarrangement ( Efnb3, Map1a, Acta ), an impaired protein quality control ( Bin1,Myl4 ) and a reduced cardiac function ( Timp4) were significantly downregulated in both the groups.

Conclusion: These findings conclude that transgenic expression of wild-type vs. mutant forms of Nrf2 in the heart uniquely regulate the myocardial transcriptome, which might result in independent pathological processes.

Reductive Stress Causes Pathological Cardiac Remodeling and Diastolic Dysfunction

Aims: Redox homeostasis is tightly controlled and regulates key cellular signaling pathways. The cell's antioxidant response provides a natural defense against oxidative stress, but excessive antioxidant generation leads to reductive stress (RS). This study elucidated how chronic RS, caused by constitutive activation of nuclear erythroid related factor-2 (caNrf2)-dependent antioxidant system, drives pathological myocardial remodeling. Results: Upregulation of antioxidant transcripts and proteins in caNrf2-TG hearts (TGL and TGH; transgenic-low and -high) dose dependently increased glutathione (GSH) redox potential and resulted in RS, which over time caused pathological cardiac remodeling identified as hypertrophic cardiomyopathy (HCM) with abnormally increased ejection fraction and diastolic dysfunction in TGH mice at 6 months of age. While the TGH mice exhibited 60% mortality at 18 months of age, the rate of survival in TGL was comparable with nontransgenic (NTG) littermates. Moreover, TGH mice had severe cardiac remodeling at ∼6 months of age, while TGL mice did not develop comparable phenotypes until 15 months, suggesting that even moderate RS may lead to irreversible damages of the heart over time. Pharmacologically blocking GSH biosynthesis using BSO (l-buthionine-SR-sulfoximine) at an early age (∼1.5 months) prevented RS and rescued the TGH mice from pathological cardiac remodeling. Here we demonstrate that chronic RS causes pathological cardiomyopathy with diastolic dysfunction in mice due to sustained activation of antioxidant signaling. Innovation and Conclusion: Our findings demonstrate that chronic RS is intolerable and adequate to induce heart failure (HF). Antioxidant-based therapeutic approaches for human HF should consider a thorough evaluation of redox state before the treatment.

Parents of Very Young Children with Congenital Heart Defects Report Good Quality of Life for Their Children and Families Regardless of Defect Severity

The purpose of this study was to investigate parent reports of quality of life for their very young children with congenital heart defects (CHD) and to compare their scores to previously published data. Parents of children 1-3 years old with CHD or innocent heart murmurs completed the Pediatric Quality of Life Inventory (PedsQL) core, cardiac, and family impact modules. Multivariable regression analyses assessed the impact of age, sex, family income, and CHD treatment history (study group) on PedsQL scores. Correlations between family impact and core/cardiac modules were examined. PedsQL scores were compared to healthy norms. 140 parents of young children participated within four study groups: CHD no treatment (n = 44), CHD treatment without bypass (n = 26), CHD treatment with bypass (n = 42) ,and innocent heart murmurs (n = 28). Male sex was associated with higher core (F = 4.16, p = 0.04, σ² = .03) and cardiac quality of life (F = 4.41, p = .04, σ² = 0.04). Higher family income was associated with higher family quality of life (F = 8.89, p < .01, σ² = 0.13). Parents of children with innocent heart murmurs and children with CHD not requiring treatment had higher core quality of life compared to young healthy children. Cardiac-related quality of life scores were associated with family impact (r = 0.68) and core module (r = 0.63) quality of life scores. Parents of very young children with CHD report good quality of life for their children and families. Quality of life exceeds in children with innocent murmurs or CHD not requiring repair. Parents report a lower quality of life among girls, and lower family quality of life is associated with lower family income.

Exercise Mediated Nrf2 Signaling Protects the Myocardium From Isoproterenol-Induced Pathological Remodeling

Although exercise derived activation of Nrf2 signaling augments myocardial antioxidant signaling, the molecular mechanisms underlying the benefits of moderate exercise training (MET) in the heart remain elusive. Here we hypothesized that exercise training stabilizes Nrf2-dependent antioxidant signaling, which then protects the myocardium from isoproterenol-induced damage. The present study assessed the effects of 6 weeks of MET on the Nrf2/antioxidant function, glutathione redox state, and injury in the myocardium of C57/BL6J mice that received isoproterenol (ISO; 50 mg/kg/day for 7 days). ISO administration significantly reduced the Nrf2 promoter activity (p < 0.05) and downregulated the expression of cardiac antioxidant genes (Gclc, Nqo1, Cat, Gsr, and Gst-μ) in the untrained (UNT) mice. Furthermore, increased oxidative stress with severe myocardial injury was evident in UNT+ISO when compared to UNT mice receiving PBS under basal condition. Of note, MET stabilized the Nrf2-promoter activity and upheld the expression of Nrf2-dependent antioxidant genes in animals receiving ISO, and attenuated the oxidative stress-induced myocardial damage. Echocardiography analysis revealed impaired diastolic ventricular function in UNT+ISO mice, but this was partially normalized in the MET animals. Interestingly, while there was a marginal reduction in ubiquitinated proteins in MET mice that received ISO, the pathological signs were attenuated along with near normal cardiac function in response to exercise training. Thus, moderate intensity exercise training conferred protection against ISO-induced myocardial injury by augmentation of Nrf2-antioxidant signaling and attenuation of isoproterenol-induced oxidative stress.

Organoruthenium(II) complexes attenuate stress in Caenorhabditis elegans through regulating antioxidant machinery

The 1:1 stoichiometric reactions of 3-methoxy salicylaldehyde-4(N)-substituted thiosemicarbazones (H₂L^1-4) with [RuCpCl(PPh₃)₂] was carried out in methanol. The obtained complexes (1-4) were characterized by analytical, IR, absorption and ¹H NMR spectroscopic studies. The structures of ligand [H₂-3MSal-etsc] (H₂L³) and complex [RuCp(Msal-etsc) (PPh₃)] (3), were characterized by single crystal X-ray diffraction studies. The interaction of the ruthenium(II) complexes (1-4) with calfthymus DNA (CT-DNA) has been explored by absorption and emission titration methods. Based on the observations, an intercalative binding mode of DNA has been proposed. The protein binding abilities of the new complexes were monitored by quenching the tryptophan and tyrosine residues of BSA, as model protein. From the studies, it was found that the new ruthenium metallacycles exhibited better affinity than their precursors. The free radical scavenging assay suggests that all complexes effectively scavenged the DPPH radicals as compared to that of standard control ascorbic acid and scavenging activities of complexes are in the order of 4 > 2 > 3 > 1. In addition, ruthenium(II) complexes (2-4) also exhibited an excellent in vivo antioxidant activity as it was able to increase the survival of worms exposed to lethal oxidative and thermal stresses possibly through reducing the intracellular ROS levels. It was interesting to note that complexes 2-4 failed to increase the lifespan of mev-1 mutant worms having shortened lifespan due to the over production of free radicals. This data confirmed that complexes 2-4 conferred stress resistance in C. elegans, but they also require an endogenous detoxification mechanism for doing so. The genetic and reporter gene expression analysis revealed that complexes 2-4 maintained the intracellular redox status and offered stress protection through transactivation of antioxidant defence machinery genes gst-4 and sod-3 which are directly regulated by SKN-1 and DAF-16 transcription factors, respectively. Altogether, our results suggested that complexes 2-4 might play a crucial role in stress modulation and they perhaps exert almost similar effects in higher models, which is an important issue to be validated in future.

East Indian sandalwood (Santalum album L.) oil confers neuroprotection and geroprotection in Caenorhabditis elegans via activating SKN-1/Nrf2 signaling pathway

East Indian Sandalwood Oil (EISO) has diverse beneficial effects and has been used for thousands of years in traditional folk-medicine for treatment of different human ailments. However, there has been no in-depth scientific investigation to decipher the neuroprotective and geroprotective mechanism of EISO and its principle components, α- and β-santalol. Hence the current study was undertaken to assess the protective effects of EISO, and α- and β-santalol against neurotoxic (6-OHDA/6-hydroxydopamine) and proteotoxic (α-synuclein) stresses in a Caenorhabditis elegans model. Initially, we found that EISO and its principle components exerted an excellent antioxidant and antiapoptotic activity as it was able to extend the lifespan, and inhibit the ROS generation, and germline cell apoptosis in 6-OHDA-intoxicated C. elegans. Further, we showed that supplementation of EISO, and α- and β-santalol reduced the 6-OHDA and α-synuclein-induced Parkinson's disease associated pathologies and improved the physiological functions. The genetic and reporter gene expression analysis revealed that an EISO, or α- and β-santalol-mediated protective effect does not appear to rely on DAF-2/DAF-16, but selectively regulates SKN-1 and its downstream targets involved in antioxidant defense and geroprotective processes. Together, our findings indicated that EISO and its principle components are worth exploring further as a candidate redox-based neuroprotectant for the prevention and management of age-related neurological disorders.

Abstract 425: A Pro-reductive Redox State Protects the Myocardium From Isoproterenol-Induced Pathological Remodeling in Nrf2 Transgenic Mouse

Background: Nuclear factor (erythroid-derived 2)-like 2 (NEFL2/Nrf2) is an inducible transcription factor that is crucial to fight against stress caused by various means (i.e. oxidative or xenobiotic stresses). While the Nrf2 has a negligible role on regulating the basal transcription of antioxidant and cytoprotective genes, its activation in response to stress is indispensable. Here, we hypothesize that augmentation of myocardial Nrf2, through transgene expression, will protect the myocardium from isoproterenol-induced pathological remodeling.

Methods: Cardiac specific Nrf2 transgenic (Nrf2-Tg) and non-transgenic (NTg) litter mates in the C57/BL6 background were subjected to isoproterenol (ISO) treatment (50 mg/kg bw/day, for 7 days), and assessed the myocardial structure, function (Echocardiography) and Nrf2-dependent defense mechanisms.

Results: Severe infarction and fibrosis along with increased inflammation leading to myocardial dysfunction in NTg mice exposed to ISO, but the Nrf2-TG hearts were found to be resistant to ISO insult. Suppression of infarction and protection of myocardial structure and function in the Nrf2-Tg mice could be attributed to a pro-reductive condition displayed in these hearts. In particular, ISO administration resulted in an excessive generation of reactive oxygen species and oxidation of proteins along with significant downregulation of antioxidant genes (p<0.05)and their proteins lead to myocardial damage in NTg mice. Of note, myocardium of ISO-treated TG mice displayed significantly reduced protein oxidation and comparable levels of antioxidant genes and proteins (p<0.05) in relation to PBS-treated NTg mice. Taken together, it is suggested that a pre-existing pro-reductive redox milieu is likely to combat ISO-induced oxidative stress, thereby protecting the myocardium from pathological remodeling.

Conclusion: Thus, we conclude that a modest trans-activation of the global antioxidant defense system might have therapeutic potential than either targeting single antioxidant (i.e. SOD or catalase or GPX) or supplementation of antioxidant combos to protect the myocardium in response to stress.

Recurrent heat shock impairs the proliferation and differentiation of C2C12 myoblasts

Heat-related illness and injury are becoming a growing safety concern for the farmers, construction workers, miners, firefighters, manufacturing workers, and other outdoor workforces who are exposed to heat stress in their routine lives. A primary response by a cell to an acute heat shock (HS) exposure is the induction of heat-shock proteins (HSPs), which chaperone and facilitate cellular protein folding and remodeling processes. While acute HS is well studied, the effect of repeated bouts of hyperthermia and the sustained production of HSPs in the myoblast-myotube model system of C2C12 cells are poorly characterized. In C2C12 myoblasts, we found that robust HS (43 °C, dose/time) significantly decreased the proliferation by 50% as early as on day 1 and maintained at the same level on days 2 and 3 of HS. This was accompanied by an accumulation of cells at G2 phase with reduced cell number in G1 phase indicating cell cycle arrest. FACS analysis indicates that there was no apparent change in apoptosis (markers) and cell death upon repeated HS. Immunoblot analysis and qPCR demonstrated a significant increase in the baseline expression of HSP25, 70, and 90 (among others) in cells after a single HS (43 °C) for 60 min as a typical HS response. Importantly, the repeated HS for 60 min each on days 2 and 3 maintained the elevated levels of HSPs compared to the control cells. Further, the continuous HS exposure resulted in significant inhibition of the differentiation of C2C12 myocytes to myotubes and only 1/10th of the cells underwent differentiation in HS relative to control. This was associated with significantly higher levels of HSPs and reduced expression of myogenin and Myh2 (P < 0.05), the genes involved in the differentiation process. Finally, the cell migration (scratch) assay indicated that the wound closure was significantly delayed in HS cells relative to the control cells. Overall, these results suggest that a repeated HS may perturb the active process of proliferation, motility, and differentiation processes in an in vitro murine myoblast-myotube model.

Excess ω-6 fatty acids influx in aging drives metabolic dysregulation, electrocardiographic alterations, and low-grade chronic inflammation

Maintaining a balance of ω-6 and ω-3 fatty acids is essential for cardiac health. Current ω-6 and ω-3 fatty acids in the American diet have shifted from the ideal ratio of 2:1 to almost 20:1; while there is a body of evidence that suggests the negative impact of such a shift in younger organisms, the underlying age-related metabolic signaling in response to the excess influx of ω-6 fatty acids is incompletely understood. In the present study, young (6 mo old) and aging (≥18 mo old) mice were fed for 2 mo with a ω-6-enriched diet. Excess intake of ω-6 enrichment decreased the total lean mass and increased nighttime carbohydrate utilization, with higher levels of cardiac cytokines indicating low-grade chronic inflammation. Dobutamine-induced stress tests displayed an increase in PR interval, a sign of an atrioventricular defect in ω-6-fed aging mice. Excess ω-6 fatty acid intake in aging mice showed decreased 12-lipoxygenase with a concomitant increase in 15-lipoxygenase levels, resulting in the generation of 15( S)-hydroxyeicosatetraenoic acid, whereas cyclooxygenase-1 and -2 generated prostaglandin E₂, leukotriene B_4, and thromboxane B₂. Furthermore, excessive ω-6 fatty acids led to dysregulated nuclear erythroid 2-related factor 2/antioxidant-responsive element in aging mice. Moreover, ω-6 fatty acid-mediated changes were profound in aging mice with respect to the eicosanoid profile while minimal changes were observed in the size and shape of cardiomyocytes. These findings provide compelling evidence that surplus consumption of ω-6 fatty acids, coupled with insufficient intake of ω-3 fatty acids, is linked to abnormal changes in ECG. These manifestations contribute to functional deficiencies and expansion of the inflammatory mediator milieu during later stages of aging. NEW & NOTEWORTHY Aging has a profound impact on the metabolism of fatty acids to maintain heart function. The excess influx of ω-6 fatty acids in aging perturbed electrocardiography with marked signs of inflammation and a dysregulated oxidative-redox balance. Thus, the quality and quantity of fatty acids determine the cardiac pathology and energy utilization in aging.

Identification of transcriptome signature for myocardial reductive stress

The nuclear factor erythroid 2 like 2 (Nfe2l2/Nrf2) is a master regulator of antioxidant gene transcription. We recently identified that constitutive activation of Nrf2 (CaNrf2) caused reductive stress (RS) in the myocardium. Here we investigate how chronic Nrf2 activation alters myocardial mRNA transcriptome in the hearts of CaNrf2 transgenic (TG-low and TG-high) mice using an unbiased integrated systems approach and next generation RNA sequencing followed by qRT-PCR methods. A total of 246 and 1031 differentially expressed genes (DEGs) were identified in the heart of TGL and TGH in relation to NTG littermates at ~ 6 months of age. Notably, the expression and validation of the transcripts were gene-dosage dependent and statistically significant. Ingenuity Pathway Analysis identified enriched biological processes and canonical pathways associated with myocardial RS in the CaNrf2-TG mice. In addition, an overrepresentation of xenobiotic metabolic signaling, glutathione-mediated detoxification, unfolded protein response, and protein ubiquitination was observed. Other, non-canonical signaling pathways identified include: eNOS, integrin-linked kinase, glucocorticoid receptor, PI3/AKT, actin cytoskeleton, cardiac hypertrophy, and the endoplasmic reticulum stress response. In conclusion, this mRNA profiling identified a "biosignature" for pro-reductive (TGL) and reductive stress (TGH) that can predict the onset, rate of progression, and clinical outcome of Nrf2-dependent myocardial complications. We anticipate that this global sequencing analysis will illuminate the undesirable effect of chronic Nrf2 signaling leading to RS-mediated pathogenesis besides providing important guidance for the application of Nrf2 activation-based cytoprotective strategies.

Genetic disruption of the cardiomyocyte circadian clock differentially influences insulin-mediated processes in the heart

Cardiovascular physiology exhibits time-of-day-dependent oscillations, which are mediated by both extrinsic (e.g., environment/behavior) and intrinsic (e.g., circadian clock) factors. Disruption of circadian rhythms negatively affects multiple cardiometabolic parameters. Recent studies suggest that the cardiomyocyte circadian clock directly modulates responsiveness of the heart to metabolic stimuli (e.g., fatty acids) and stresses (e.g., ischemia/reperfusion). The aim of this study was to determine whether genetic disruption of the cardiomyocyte circadian clock impacts insulin-regulated pathways in the heart. Genetic disruption of the circadian clock in cardiomyocyte-specific Bmal1 knockout (CBK) and cardiomyocyte-specific Clock mutant (CCM) mice altered expression (gene and protein) of multiple insulin signaling components in the heart, including p85α and Akt. Both baseline and insulin-mediated Akt activation was augmented in CBK and CCM hearts (relative to littermate controls). However, insulin-mediated glucose utilization (both oxidative and non-oxidative) and AS160 phosphorylation were attenuated in CBK hearts, potentially secondary to decreased Inhibitor-1. Consistent with increased Akt activation in CBK hearts, mTOR signaling was persistently increased, which was associated with attenuation of autophagy, augmented rates of protein synthesis, and hypertrophy. Importantly, pharmacological inhibition of mTOR (rapamycin; 10days) normalized cardiac size in CBK mice. These data suggest that disruption of cardiomyocyte circadian clock differentially influences insulin-regulated processes, and provide new insights into potential pathologic mediators following circadian disruption.

Constitutive activation of Nrf2 induces a stable reductive state in the mouse myocardium

Redox homeostasis regulates key cellular signaling pathways in both physiology and pathology. The cell's antioxidant response provides a defense against oxidative stress and establishes a redox tone permissive for cell signaling. The molecular regulation of the well-known Keap1/Nrf2 system acts as sensor responding to changes in redox homeostasis and is poorly studied in the heart. Importantly, it is not yet known whether Nrf2 alone can serve as a master regulator of cellular redox homeostasis without compensation of the transcriptional regulation of antioxidant response element (ARE) genes through alternate mechanisms. Here, we addressed this question using cardiac-specific transgenic expression at two different levels of constitutively active nuclear erythroid related factor 2 (caNrf2) functioning independently of Keap1. The caNrf2 mice showed augmentation of glutathione (GSH), the key regulator of the cellular thiol redox state. The Trans-AM assay for Nrf2-binding to the antioxidant response element (ARE) showed a dose-dependent increase associated with upregulation of several major antioxidant genes and proteins. This was accompanied by a significant decrease in dihydroethidium staining and malondialdehyde (MDA) in the caNrf2-TG mice myocardium. Interestingly, caNrf2 gene-dosage dependent redox changes were noted resulting in generation of a multi-stage model of pro-reductive and reductive conditions in the myocardium of TG-low and TG-high mice, respectively. These data clearly show that Nrf2 levels alone are capable of serving as the master regulator of the ARE. These models provide an important platform to investigate the impact of the Nrf2 system independent of the need to regulate the activity of Keap1 and the consequent exposure to pro-oxidants or electrophiles, which have numerous off-target effects.

Abstract 458: Moderate Exercise Training Attenuates Isoproterenol-Induced Myocardial Injury by Activating Nrf2-Signaling

Background: Nuclear erythroid-2 like factor-2 (Nrf2), a master transcriptional regulator of antioxidants, is critical to maintain cellular redox homeostasis. We recently reported that exercise training activates Nrf2/antioxidant signaling in the heart. Isoproterenol (ISO) mediated structural, and functional changes in the heart involve oxidative stress. Here, we tested a hypothesis that moderate exercise training will protect the myocardium from isoproterenol-induced injury by augmenting Nrf2-dependent antioxidant defense system.

Methods: Age- and sex-matched WT (C57/BL6) mice (6-8 months old) were subjected to moderate exercise training (MET) on a treadmill for 6 weeks (60 min/day; 10m/min; 0% grade). Randomly assigned untrained (UNT) and trained (MET) animals were intraperitoneally injected (at the start of 6 th week) with 50 mg of isoproterenol/kg.bw./day for 7 consecutive days. MET was continued during ISO administration and the animals (UNT + PBS, UNT + ISO; MET + ISO) underwent echocardiography analysis. Heart tissues were collected for histopathology, Nrf2-ARE promoter binding assay (Active-motif TransAM kit), antioxidant gene (qPCR) and protein (Immunoblotting) levels, and glutathione redox status.

Results: ISO administration significantly reduced the Nrf2 promoter activity (p<0.05) and downregulated the expression of cardiac antioxidant genes ( Gclc, Nqo1, Cat, Gsr and Gst-μ ) in UNT mice. Further, increased oxidative stress with severe myocardial injury was evident in UNT+ISO when compared to UNT mice receiving PBS under basal condition. Interestingly, MET stabilized the Nrf2-promoter activity and promoted the expression of Nrf2-dependent antioxidant genes and proteins animals receiving ISO, and thereby attenuated the oxidative stress-induced myocardial damage. Echocardiography analysis showed impaired systolic/diastolic ventricular volumes coupled with decreased cardiac output in UNT+ISO mice, but this was normalized in exercise-trained animals.

Conclusion: Thus moderate exercise training conferred protection against ISO-induced myocardial injury by augmentation of Nrf2-antioxidant signaling and attenuation of redox perturbations.

Abstract 112: Cardiac-specific Constitutive Activation of Nrf2 Induces Reductive Stress and Pathological Cardiac Remodeling

Background: Heart failure is a growing cause of human morbidity and mortality. Supplementations of free radical scavenging antioxidants have largely failed to protect the myocardium from oxidative stress diseases. While endogenous transcriptional activation of antioxidants appears to be promising, their chronic effects are unknown. Here, we tested a hypothesis that chronic activation of antioxidant system will result in reductive stress (RS) and lead to pathological cardiac hypertrophy.

Methods: Novel transgenic (TG) mice expressing constitutively active Nrf2 in the heart (α-MHC-caNrf2-TG) and their littermates were used to study the effects on structure and function of the myocardium. Myocardial glutathione redox state (GSH/GSSG), transcript levels (qPCR), and protein (immunoblotting) for Nrf2-related antioxidants and structure and function analysis (echocardiography - Vevo2100 Imager) in Non-transgenic (NTg), TG-low and TG-high mice (n=6-12/gp.) were performed at 6-8 months of age. Further, changes in cardiomyocytes and rate of survival in TG mice were analyzed.

Results: Kaplan-Meier survival plots demonstrated 10 and 40% mortality in TG-low and TG-high, respectively, compared to NTG by 60 weeks of age. The myocardial glutathione and its redox ratio (GSH/GSSG) were significantly increased (p<0.05) in the TG-low and TG-high compared with NTg mice indicates development of RS. A significant increase in Nrf2-ARE (promoter) binding with increased expression of antioxidant genes and proteins (p<0.05) were noted in TG vs. NTg mice. Increased heart-to-body weight and heart weight to tibia length ratios were prominent in TG-high relative to NTg or TG-low mice. Histological analyses (WGA, H&E staining) showed increased cardiomyocyte size, ventricular wall thickening and decreased chamber volume in TG mice. Echocardiography analyses revealed significant hypertrophic cardiomyopathy with abnormally increased ejection fraction (HCM i EF) due to chronic reductive stress.

Conclusion: Thus, basal attenuation of the obligatory oxidative signaling with chronic activation of Nrf2-antioxidants could shift the redox equilibrium to “reductive” side and thereby causing pathological cardiac remodeling.

Abstract 170: Differential Regulation of miRNA and mRNA Expression in the Myocardium of Nrf2 Knockout Mice

Background: Preclinical studies indicate that disruption of the transcription factor nuclear factor, erythroid 2 like 2 (Nrf2) leads to pathological oxidative stress in several tissues. However, the transcriptional role of Nrf2 in the heart, a highly aerobic organ sensitive to redox disturbances and aberrant microRNA (miRNA) activity, remains elusive. Here, we tested the hypothesis that Nrf2 ablation disrupts cardiac miRNA abundance leading to impaired transcriptional regulation of the myocardial defense system.

Methods: Age-matched wild-type (WT) and Nrf2 knockout (Nrf2 -/- ) mice (n=3-6/group) were used in this study. Independent next-generation sequencing experiments were conducted to evaluate differential expression of mRNA and miRNA in the heart. Real-time qPCR was used to validate RNA sequencing (RNAseq) data.

Results: RNAseq for mRNA uncovered 152 differentially expressed genes (DEGs) in Nrf2 -/- hearts, of which 129 were downregulated relative to WT. Novel DEGs previously unreported as Nrf2 targets were detected and Gene Ontology analysis revealed the enrichment (p<0.05) of several biological processes distinct from canonical Nrf2 function including; wound healing, protein folding, cytokine response, cell migration and adhesion. In line with previous reports, altered regulation of apoptosis, stress response and oxidative metabolism was also implicated in Nrf2 -/- DEG signatures. Next, small RNAseq detected a total of 27 miRNAs (11 up and 16 downregulated) altered in Nrf2 -/- mice. Validation by qPCR revealed a significant (p<0.05) decrease in miR-10b-5p, miR-674-3p, miR-3535, and miR-378c while miR-30b-5p, miR-208a-5p, miR-350-3p, miR-582-5p, and miR-1249-3p were increased. In silico integration of RNAseq data discovered complementarity between 39 repressed mRNAs and 4 upregulated miRNAs; miR-30b-5p, miR-208a-5p, miR-350-3p, and miR-582-5p. These miRNAs may cooperatively regulate expression in Nrf2 -/- hearts as 22 DEGs matched with 2 or more miRNAs.

Conclusion: Our results highlight novel mRNA targets and indicate that Nrf2 regulates a subset of cardiac miRNAs. Biological changes distinct from canonical Nrf2 function suggest that regulatory cross-talk with miRNAs contribute to unique roles for Nrf2 in the myocardium.

Abstract 374: Evidence for Hyper-reductive and Hyper-oxidative Conditions in Heart Failure Patients

Background: Oxidative stress has been linked to heart failure (HF) in humans. Antioxidant-based treatments are not always effective. Hence, we tested a hypothesis that some patients with heart failure may have a hyper-reductive state. Identifying this condition may lead to personalized optimization and better outcomes.

Methods: Blood samples were collected from age and sex matched healthy control (n=50) and HF patients (n=55). Serum was separated and stored immediately in -80°C until analysis. Reduced glutathione (GSH) and its redox ratio (GSH/GSSG) using sigma GSH kit (38185) and malondialdehyde (MDA) levels by HPLC in the serum of HF patients were quantified. Further, the activities of key antioxidant enzymes including catalase, SOD, glutathione peroxidase and glutathione reductase were analyzed using a kinetic spectrophotometer.

Results: While majority of the HF patients had significantly decreased the glutathione redox status (GSH/GSSG) and increased MDA levels (lipid peroxidation index) indicating a hyper-oxidative state, a subset of HF patients (n=8) displayed a significantly increased GSH/GSSG ratio along with decreased MDA levels in the serum, suggesting a strong association for a hyper-reductive state in the development of HF. Moreover, closer analyses of echocardiography revealed a lower ejection fraction (EF) with substantial diastolic dysfunction (MV E/A) in the HF patients with hyper-reductive state.

Conclusion: These results suggest that hyper-reductive condition may indicate a worsening clinical course for HF patients. Thus a thorough diagnosis of redox state and personalized approach for antioxidant treatment is warranted.

Chronic Endurance Exercise Impairs Cardiac Structure and Function in Middle-Aged Mice with Impaired Nrf2 Signaling

Nuclear factor erythroid 2 related factor 2 (Nrf2) signaling maintains the redox homeostasis and its activation is shown to suppress cardiac maladaptation. Earlier we reported that acute endurance exercise (2 days) evoked antioxidant cytoprotection in young WT animals but not in aged WT animals. However, the effect of repeated endurance exercise during biologic aging (WT) characterized by an inherent deterioration in Nrf2 signaling and pathological aging (pronounced oxidative susceptibility-Nrf2 absence) in the myocardium remains elusive. Thus, the purpose of our study was to determine the effect of chronic endurance exercise-induced cardiac adaptation in aged mice with and without Nrf2. Age-matched WT and Nrf2-null mice (Nrf2-/-) (>22 months) were subjected to 6 weeks chronic endurance exercise (25 meter/min, 12% grade). The myocardial redox status was assessed by expression of antioxidant defense genes and proteins along with immunochemical detection of DMPO-radical adduct, GSH-NEM, and total ubiquitination. Cardiac functions were assessed by echocardiography and electrocardiogram. At sedentary state, loss of Nrf2 resulted in significant downregulation of antioxidant gene expression (Nqo1, Ho1, Gclm, Cat, and Gst-α) with decreased GSH-NEM immuno-fluorescence signals. While Nrf2-/- mice subjected to CEE showed an either similar or more pronounced reduction in the transcript levels of Gclc, Nqo1, Gsr, and Gst-α in relation to WT littermates. In addition, the hearts of Nrf2-/- on CEE showed a substantial reduction in specific antioxidant proteins, G6PD and CAT along with decreased GSH, a pronounced increase in DMPO-adduct and the total ubiquitination levels. Further, CEE resulted in a significant upregulation of hypertrophy genes (Anf, Bnf, and β-Mhc) (p < 0.05) in the Nrf2-/- hearts in relation to WT mice. Moreover, the aged Nrf2-/- mice exhibited a higher degree of cardiac remodeling in association with a significant decrease in fractional shortening, pronounced ST segment, and J wave elevation upon CEE compared to age-matched WT littermates. In conclusion, our findings indicate that while the aged WT and Nrf2 knockout animals both exhibit hypertrophy after CEE, the older Nrf2 knockouts showed ventricular remodeling coupled with profound cardiac functional abnormalities and diastolic dysfunction.

Abstract 562: Impaired Transcriptional Regulation of Nrf2 and Antioxidant Signaling in Vascular Tissue of Aging Mice

Background: Chronic oxidative stress and dysregulation of vascular system are tightly linked to cardiac structure-function anomalies. We hypothesized that nuclear erythroid-2 like factor-2 (Nrf2), a redox-sensitive transcriptional regulator, distinctly regulate antioxidant transcription in aortic vessels on aging versus high intensity exercise stress (HIES).

Methods: Age and sex matched wild-type (WT) and Nrf2 -/- mice at young (3 months) and old (>20 months) ages were used in this study. Effect of loss of function for Nrf2 on transcription and translation of targets involve in antioxidant signaling was studied in response to HIES on aging.

Results: Under basal setting, Nrf2 abrogation resulted in moderate downregulation of a subset of antioxidant gene expression ( G6pd, catalase, Gclc, Gclm, Gstα, Gstμ, and Nqo1 ) in aortic vessel in relation to age-matched wild-type (WT) mice. Interestingly, some of the antioxidant genes ( G6pd, Sod1, Sod2, Ho1, Gclc, Gclm, Gstα and Gstμ ) were significantly downregulated in old-WT when compared to young-WT mice, suggesting age-associated impairment of Nrf2-dependent antioxidant signaling. On the other hand, the expression of certain antioxidant genes ( Gclm, Catalase, Gsr, Nqo1, Gpx1 and Gstμ ) were similar in HIES-subjected WT and Nrf2 -/- mice in relation to sedentary controls at old age. These observations suggest that the response to HIES is blunted on aging due to either impairment or ablation of Nrf2 in WT versus knockout mice. In addition, we observed a significant increase in mRNA levels of Keap1, G6pd, Sod1 and Sod2 in aorta of Nrf2 -/- mice when compared to its WT counterparts. These results indicate that either abrogation (in Nrf2 -/- mice) or age-associated decline (in old WT mice) of Nrf2 describes a distinctive molecular phenotype related to transcriptional regulation of redox signaling on aging.

Conclusion: Thus, our findings direct that dysregulation and/or absence of Nrf2 could impair the physiological adaptive events of aortic vessel to intense exercise stress tending to pathologic vascular remodeling and may therefore result in cardiovascular complications.

Abrogation of Nrf2 impairs antioxidant signaling and promotes atrial hypertrophy in response to high-intensity exercise stress

BACKGROUND

Anomalies in myocardial structure involving myocyte growth, hypertrophy, differentiation, apoptosis, necrosis etc. affects its function and render cardiac tissue more vulnerable to the development of heart failure. Although oxidative stress has a well-established role in cardiac remodeling and dysfunction, the mechanisms linking redox state to atrial cardiomyocyte hypertrophic changes are poorly understood. Here, we investigated the role of nuclear erythroid-2 like factor-2 (Nrf2), a central transcriptional mediator, in redox signaling under high intensity exercise stress (HIES) in atria.

METHODS

Age and sex-matched wild-type (WT) and Nrf2(-/-) mice at >20 months of age were subjected to HIES for 6 weeks. Gene markers of hypertrophy and antioxidant enzymes were determined in the atria of WT and Nrf2(-/-) mice by real-time qPCR analyses. Detection and quantification of antioxidants, 4-hydroxy-nonenal (4-HNE), poly-ubiquitination and autophagy proteins in WT and Nrf2(-/-) mice were performed by immunofluorescence analysis. The level of oxidative stress was measured by microscopical examination of di-hydro-ethidium (DHE) fluorescence.

RESULTS

Under the sedentary state, Nrf2 abrogation resulted in a moderate down regulation of some of the atrial antioxidant gene expression (Gsr, Gclc, Gstα and Gstµ) despite having a normal redox state. In response to HIES, enlarged atrial myocytes along with significantly increased gene expression of cardiomyocyte hypertrophy markers (Anf, Bnf and β-Mhc) were observed in Nrf2(-/-) when compared to WT mice. Further, the transcript levels of Gclc, Gsr and Gstµ and protein levels of NQO1, catalase, GPX1 were profoundly downregulated along with GSH depletion and increased oxidative stress in Nrf2(-/-) mice when compared to its WT counterparts after HIES. Impaired antioxidant state and profound oxidative stress were associated with enhanced atrial expression of LC3 and ATG7 along with increased ubiquitination of ATG7 in Nrf2(-/-) mice subjected to HIES.

CONCLUSIONS

Loss of Nrf2 describes an altered biochemical phenotype associated with dysregulation in genes related to redox state, ubiquitination and autophagy in HIES that result in atrial hypertrophy. Therefore, our findings direct that preserving Nrf2-related antioxidant function would be one of the effective strategies to safeguard atrial health.

Disruption of nuclear factor (erythroid-derived-2)-like 2 antioxidant signaling: a mechanism for impaired activation of stem cells and delayed regeneration of skeletal muscle

Recently we have reported that age-dependent decline in antioxidant levels accelerated apoptosis and skeletal muscle degeneration. Here, we demonstrate genetic ablation of the master cytoprotective transcription factor, nuclear factor (erythroid-derived-2)-like 2 (Nrf2), aggravates cardiotoxin (CTX)-induced tibialis anterior (TA) muscle damage. Disruption of Nrf2 signaling sustained the CTX-induced burden of reactive oxygen species together with compromised expression of antioxidant genes and proteins. Transcript/protein expression of phenotypic markers of muscle differentiation, namely paired box 7 (satellite cell) and early myogenic differentiation and terminal differentiation (myogenin and myosin heavy chain 2) were increased on d 2 and 4 postinjury but later returned to baseline levels on d 8 and 15 in wild-type (WT) mice. In contrast, these responses were persistently augmented in Nrf2-null mice suggesting that regulation of the regeneration-related signaling mechanisms require Nrf2 for normal functioning. Furthermore, Nrf2-null mice displayed slower regeneration marked by dysregulation of embryonic myosin heavy chain temporal expression. Histologic observations illustrated that Nrf2-null mice displayed smaller, immature TA muscle fibers compared with WT counterparts on d 15 after CTX injury. Improvement in TA muscle morphology and gain in muscle mass evident in the WT mice was not noticeable in the Nrf2-null animals. Taken together these data show that the satellite cell activation, proliferation, and differentiation requires a functional Nrf2 system for effective healing following injury.-Shelar, S. B., Narasimhan, M., Shanmugam, G., Litovsky, S. H., Gounder, S. S., Karan, G., Arulvasu, C., Kensler, T. W., Hoidal, J. R., Darley-Usmar, V. M., Rajasekaran, N. S. Disruption of nuclear factor (erythroid-derived-2)-like 2 antioxidant signaling: a mechanism for impaired activation of stem cells and delayed regeneration of skeletal muscle.

Abstract 133: Impaired TNFα Signaling Deregulates Basal Nrf2-Antioxidant System in Myocardium

Antagonizing TNF-α and its signaling is proven to be a successful therapeutic strategy in various disease processes. Although blocking TNF-α signaling attenuated the disease activity, the overarching clinical contraindications remains to be a greater concern and reasons for the adverse effects are largely unknown. TNF-α induces ROS and as ROS is pivotal for activation of antioxidant transcription factor, Nrf2, we posit that any impairment in TNF-α signaling could affect Nrf2-dependent basal redox homeostasis. HL-1 cardiomyocytes, TNFR1/2 double knockout mice (DKO) that shows hampered TNF-α signaling were used as experimental models. Electron Paramagnetic Resonance Spectroscopy (EPR) measurements revealed that as low as 2 ng TNF-α/ml, ROS was induced significantly (p10ng/ml in HL-1 cells. TNF-α (2-5 ng /ml, for 2 h) evoked robust (p<0.05, n=3) nuclear translocation of Nrf2 and increased nuclear binding (Trans AM DNA binding analysis) along with significant (p<0.05) induction in trans-activation of Nrf2 targets. Additionally, this was associated with 2-fold increase (p<0.05) in intracellular glutathione (GSH) that is associated with significant cell death only at higher (>10 - 50 ng/ml) and later time points (12 h and 24 h). These results suggest that TNF-α mediated ROS induction activates Nrf2 dependent antioxidant system in cardiomyocytes. In vivo experiments with TNFR1/2 DKO demonstrates that the expression of Nrf2-regulated genes were significantly downregulated indicating a weakened antioxidant system. Also, the acute exercise stress (AES) induced Nrf2 trans-activation observed in WT mice was significantly blunted in TNFR1/2 DKO suggesting a need for TNF signaling in stress induced Nrf2 activation. These results support the concept that complete and/or sustained blockade of TNF signaling may result in compromised Nrf2-dependent antioxidant defense in the myocardium. This further necessitates that during chronic anti-TNF-α treatment, a finely tuned and maintenance of specific threshold of TNF-α signaling is essential to avoid oxidant stress based complications in cardiovascular system.

Abstract 218: Chemical Induced Reductive Stress Causes Cardiomyocyte Hypertrophy

Background: Progressive accumulation of misfolded or unfolded proteins is a symbol of impaired proteostasis and proteotoxicity. Such a chronic proteotoxicity is amenable to cell types that are post mitotically matured with lack of further differentiation or proliferation. Our recent discovery using a mouse model of familial human cardiac disease displayed protuberant shift in the redox state towards reductive stress (RS) in association with accumulation of toxic protein aggregates. Further, sustained trans-activation of Nrf2/antioxidant signaling caused RS in the myopathy hearts. Accordingly, we hypothesized that whether profound activation of Nrf2/antioxidant signaling and subsequent RS may cause pathological remodeling in cardiomyocyte. The aim of this study was to investigate the effect of sustained pharmacological activation of Nrf2 on cardiac remodeling. Methods: HL1 cardiomyocytes were used as an in vitro model to study the RS-mediated cardiac remodeling. They were treated with 2-10 μM of potential Nrf2-inducers; sulforaphane (SF), di-methyl fumarate (DMF) and novel small molecules (C-38, C-50, C-63 and C-66) to establish RS by sustained activation of Nrf2/antioxidant signaling. Next, we investigated the implications of RS in cardiomyocyte remodeling by analyzing transcriptional and translational mechanisms using immunoblotting, qPCR, immunofluorescence, GSH and NADPH redox measurements in HL1 cells. Results: Dose dependent effects for individual small molecules including known Nrf2 inducers (SF and DMF) revealed distinct pro-reductive and reductive intracellular (i.e. reductive stress) environments. In fact, the obligatory activation of Nrf2 signaling was associated with significant upregulation of antioxidant enzymes and small molecular thiols including glutathione (GSH). Surprisingly, while pro-reductive condition in HL1 cells was subdued, the RS induced cardiomyocyte hypertrophy was evident from microscopic examination and molecular signature (increased expression of ANF and BNF) after 24-48 hrs of Nrf2 activation. Conclusion: In summary, the chemical induced sustained activation of Nrf2 leading to formation of reductive stress showed hypertrophic remodeling in HL1 cardiomyocytes.

Spectroscopic, nonlinear optical and quantum chemical studies on Pyrrolidinium p-Hydroxybenzoate--a phase matchable organic NLO crystal

Good quality and bulk single crystals of Pyrrolidinium p-Hydroxybenzoate (PYPHB), a newly identified nonlinear optical material, were grown for the first time. It crystallizes in monoclinic system with an acentric space group Cc. The molecular structure including carbon, proton positions and functional groups has been confirmed through nuclear magnetic resonance and Fourier transform infrared spectra. Its transmission window has been observed for UV-VIS-NIR region along with its theoretical limit. The photoluminescence behavior has been observed by exciting the crystal at 310 nm. The principal refractive indices and second order NLO coefficient of PYPHB are determined by Mach-Zehnder interferometer and Maker-Fringe experiments respectively. The coherence length and phase-matchablility of PYPHB crystals are measured to explore its efficacy towards device fabrications. The dipole moment, polarizability and molecular orbital energy of an isolated PYPHB molecule have also been calculated theoretically and the results are found to corroborate the experimental values.

Ligation of RAGE with ligand S100B attenuates ABCA1 expression in monocytes

HYPOTHESIS

ATP Binding Cassette Transporter (ABC) A1 is one of the key regulators of HDL synthesis and reverse cholesterol transport. Activation of Receptors for Advanced Glycation End products (RAGE) is involved in the pathogenesis of diabetes, and its complications. The aim of the present study is to examine the effect of RAGE ligand S100B on ABCA1 expression.

METHODS

S100B mediated regulation of LXR target genes like ABCA1, ABCG1, ABCG8, LXR-α and LXR-β in THP-1 cells was analyzed by real-time PCR, RT-PCR and western blots. ABCA1 mRNA expression in monocytes from diabetic patients was studied. Effect of LXR ligand on S100B induced changes in LXR target genes was also studied. Luciferase reporter assay was used for S100B induced ABCA1 promoter regulation.

RESULTS

S100B treatment resulted in a significant 2-3 fold reduction (p<0.01) in ABCA1 and ABCG1 mRNA in dose and time dependent manner in THP1 cells. ABCA1 protein level was also significantly (p<0.01) reduced. S100B-induced reduction on ABCA1 mRNA expression was blocked by treating THP-1 cell with anti-RAGE antibody. Reduced ABCA1 mRNA levels seen in peripheral blood monocytes from diabetes patients showed the in-vivo relevance of our in-vitro results. Effect of S100B on ABCA1 and ABCG1 expression was reversed by LXR ligand treatment. S100B treatment showed significant 2 fold (p<0.01) decrease in T1317 induced ABCA1 promoter activation.

CONCLUSIONS

These results show for the first time that ligation of RAGE with S100B can attenuate the expression of ABCA1 and ABCG1 through the LXRs. This could reduce ApoA-I-mediated cholesterol efflux from monocytes.

Spectroscopic, quantum-chemical and X-ray diffraction studies of Piperidinium p-Hydroxybenzoate-combined experimental and theoretical studies on a novel NLO crystal

Large size and high quality single crystals of organic nonlinear optical material Piperidinium p-Hydroxybenzoate (PDPHB) have been grown by solution growth method. This crystal belongs to monoclinic system with a noncentrosymmetric space group of Cc. To confirm its structure and compositions this material was subjected to single and powder X-ray diffraction and microanalysis studies. Fourier transform infrared (FTIR), UV-VIS-NIR, photoluminescence and nuclear magnetic resonance spectra have been recorded and extensive spectroscopic investigations have been carried out. Frequency conversion property of the crystal was tested by using Kurtz and Perry powder technique and the relative conversion efficiency was about 19 times greater than that of KDP. Static and dynamic hyperpolarizability values were calculated to confirm the suitability of the crystal for nonlinear optical applications. In addition, frontier molecular orbital (FMO), Mulliken charge and molecular electrostatic potential (MEP) analyses were performed by density functional theory (DFT) at the B3LYP/6-31G (d) basis set.

Spectroscopic, thermal and mechanical studies on 4-methylanilinium p-toluenesulfonate - a new organic NLO single crystal

Bulk crystals of newly identified organic nonlinear optical material 4-methylanilinium p-toluenesulfonate (PMPT) were grown by slow evaporation solution growth method using ethanol as a solvent. It crystallizes in monoclinic system with a noncentrosymmetric space group P2(1). The formation of the title compound was confirmed through microanalysis, X-ray diffraction and density measurements. The proton positions and functional groups have been identified and confirmed through nuclear magnetic resonance and Fourier transform infrared spectrums respectively. Optical properties are determined by UV-Visible and photoluminescence spectroscopic studies to explore its efficacy towards device fabrications. Thermal studies exhibited that the newly obtained PMPT crystals are stable up to 199 °C. Its mechanical strength was studied by Vickers micro hardness studies.

Erratum: 6'-Amino-3'-methyl-2-oxo-1'-phenyl-1',3a',4',7a'-tetra-hydrospiro-[1H-indole-3(2H),4'-pyrano[2,3-d]pyrazole]-5'-carbonitrile. Corrigendum

The title and chemical structural diagram in Etti, Shanmugam & Perumal [Acta Cryst. (2008), E64, o341] are corrected.[This corrects the article DOI: 10.1107/S1600536807064926.].

Polymorphism in ADH and MTHFR genes in oral squamous cell carcinoma of Indians

OBJECTIVES

Alcohol consumption is known to increase the risk for several cellular disorders like oral cancer. The risk may be reinforced by polymorphism in genes like alcohol dehydrogenase. Therefore, this study is designed to asses the polymorphic status in ADH1B (formerly ADH2), ADH1C (formerly ADH3) and MTHFR genes in order to correlate the susceptibility to oral squamous cell carcinoma (OSCC).

SUBJECTS AND METHODS

DNA from 126 OSCC samples were amplified using primers for ADH1B, ADH1C and MTHFR genes. The amplicons were analyzed for ADH1B*1, ADH1C*2 and MTHFR C677T allelic polymorphism by restriction digestion using appropriate enzymes.

RESULTS

ADH1B*1/*1 genotype in cancer patients who were heavy drinkers showed a negligible risk association with an odds ratio of 1.62; 95% CI = 1.08-2.14. In OSCC patients, ADH1C*2/*2 genotypes showed a relatively higher risk (odds ratio 2.65; 95% CI = 1.78-3.53) in heavy drinkers and a less significant risk (1.6; 95% CI = 1.15-2.03) in moderate drinkers and negligible risk in light drinkers (1.23; 95% CI = 0.77-1.63). In contrast, MTHFR 677TT genotype showed a high risk association for OSCC in heavy drinkers (odds ratio 3.0; 95% CI = 2.02-4.0). Interestingly, the combination of ADH1B*1/*1/ MTHFR 677TT genotypes in alcoholic cancer patients showed a high risk (odds ratio 4.16; 95% CI = 2.78-5.53). A similar risk (odds ratio 4.16; 95% CI = 1.18-5.53) was shown by ADH1B*1/*2/*2/*2MTHFR 677TT genotype combination. The ADH1C*2/*2 /MTHFR 677TT genotype combination showed the maximum risk (odds ratio 20; 95% CI = 13.45-26.64) in the heavy drinker group. This combination showed a high risk in moderate drinkers (odds ratio 5.88; 95% CI = 4.24-7.50) and relatively lower risk in light drinkers (odds ratio 2.77; 95% CI = 1.74-3.68).

CONCLUSIONS

The ADH1C*2/*2/MTHFR 677TT genotype combination appears to be more susceptible for OSCC, since it showed a 20-fold increase in risk in heavy drinkers and a 5.9- and 2.8-fold increase in risk respectively in moderate drinkers and light drinkers. This study suggests the association of ADH1C*2/*2/MTHFR 677TT genotype combination as a risk factor for OSCC in alcoholics.

3-[3-(4-Bromophenyl)-1-phenyl-1H-pyrazol-4-yl]-5-ethoxy-2-phenylisoxazolidine

In the title compound, C₂₆H₂₄BrN₃O₂, the isoxazolidine ring adopts an envelope conformation, the ring N atom deviating from the mean plane of the other four atoms by an angle of 0.286°. The orientation of the phenyl ring is +sp and the bromophenyl ring is +sc relative to the attached pyrazole ring; the dihedral angles between the least-squares planes of the pyrazole and the attached phenyl and bromophenyl rings are 21.8 (3) and 41.8 (3)°.

Promoter hypermethylation analysis in myelodysplastic syndromes: diagnostic & prognostic implication

BACKGROUND & OBJECTIVE

Myelodysplastic syndromes (MDS) are a heterogenous group of haematopoietic stem cell disorders that are multifactorial in their aetiology. Unique genetic alterations in combinations or in isolation account for a small fraction of MDS suggesting the epigenetic hypermethylation as a possible leading cause for MDS and its transformation to acute myelocytic leukaemia (AML). Therefore, in this study, promoter hypermethylation status of key cell cycle regulators was assessed as markers in MDS patients and association of hypermethylation with clinical progression of disease was also studied.

METHODS

Promoter hypermethylation analysis of five tumour associated genes namely p16, p15, MGMT, hMLH1 and E-cadherin were done for 41 MDS patient samples with its various subtype. The hypermethylation analysis was done by using semi-nested multiplex PCR.

RESULTS

Eighty per cent of (33/41) of the MDS samples were found to be methylated in any one of the four genes (p16, p15, MGMT and E-cadherin). The p15 methylation was found to be the most frequent 61 per cent (25/41), E-cadherin was methylated in 39 per cent (16/41) and p16 in 37 per cent (15/41) of the cases. MGMT gene showed a low 5 per cent (2/41) methylation whereas hMLH1 gene was not methylated in any one of the samples analysed.

INTERPRETATION & CONCLUSION

Differential rate of methylation of the four genes (p16, p15, MGMT and E-cadherin) was observed in MDS samples. All the samples analysed showed the absence of a methylator phenotype in MDS. The methylation frequency of all these genes increased with the clinical severity of the MDS subtypes. Therefore, hypermethylation may be used as a diagnostic and prognostic tool in ascertaining the clinical severity of MDS.

Methylation of E-cadherin and hMLH1 genes in Indian sporadic breast carcinomas

Hypermethylation of promoter regions leading to inactivation of tumor suppressor genes is a common event in the progression of several tumor types. We have employed a novel restriction digestion based multiplex PCR assay to analyse the methylation status of promoter regions of tumor suppressor genes (p16, hMLH1, MGMT and E-cadherin) in sporadic breast carcinomas of Indian women. The present results indicated the absence of hypermethylation in promoter region of p16 and MGMT genes. However, 6 of the 19 (31.6%) sporadic breast carcinomas showed hypermethylation in the promoters of two of the genes analysed; three in hMLH1 and another three in E-cad. Since our earlier studies have shown lack of genetic alterations such as missense mutations and deletions in the tumor associated genes-p16, ras and p14ARF in sporadic breast tumors, the epigenetic alterations of the two genes reported in the present study could be of interest and might be among the events in the genesis/progression of sporadic breast carcinomas.

Cleistanthin B causes G1 arrest and induces apoptosis in mammalian cells

Cleistanthin B is a potential anticancer agent isolated from the tropical plant Cleistanthus collinus. We have previously shown that cleistanthin B is clastogenic and induces micronuclei formation and chromosomal aberrations. We now show that this compound inhibits DNA synthesis in Chinese hamster ovary (CHO) cells and induces apoptosis in cervical carcinoma (SiHa) cells. Flow cytometric analysis of cleistanthin treated CHO cells revealed that they were blocked in G1. Cervical carcinoma (SiHa) cells exposed to cleistanthin B shrank, rounded up and had condensed chromatin and fragmented nuclei. DNA isolated from cleistanthin treated cells exhibited the characteristic apoptotic ladder when electrophoresed in agarose gels. These results were confirmed by flow cytometry. Etoposide, a structurally similar compound also induced apoptosis in these cells although with a difference. Etoposide induced apoptosis after permitting cells to enter into S phase, while cleistanthin B stopped entry of cells into S phase and subsequently drove them to apoptosis.