bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic variation in the sucrase‐isomaltase (SI) gene is associated with dietary intake in a young adult population
Authors: Sorkin Riva , Wolever Thomas , El‐Sohemy Ahmed 
Published: November 2023

BackgroundGenetic variation contributes to individual differences in energy and nutrient intake and may be a contributing factor to the selection of certain foods and macronutrient preference. Sucrase‐isomaltase is a brush border enzyme encoded by the SI gene and plays an important role in starch digestion. Research on genetic variation in SI has mostly focused on rare mutations that result in congenital sucrase‐isomaltase deficiency, a severe digestive disorder. The objective of this study was to determine whether common variants in the SI gene are associated with habitual dietary intake.MethodsFasting blood samples were drawn from a total of 1,400 ethno‐culturally diverse participants aged 20–29 years from the Toronto Nutrigenomics and Health Study for genotyping of 5 single nucleotide polymorphisms (SNPs) in the SI gene: rs4557160 (C > T), rs7649108 (C >T), rs9756306 (G >A), rs12496714 (A >T) and rs13069478 (C >T). Dietary intake was assessed using a one‐month, 196‐item Toronto‐modified Willett food frequency questionnaire. The prevalence of the SI gene variants was compared using χ2. An analysis of covariance adjusted for age, sex, ethnicity, BMI, and physical activity was used to determine the association between SI genotypes and dietary intake.ResultsAmong Caucasians rs9756306 and rs12496714 were associated with total energy intake. Carriers of the minor allele had significantly higher energy intakes 2112 vs. 1194 kcal/day, p = 0.02 and 2011 vs. 1990 kcal/day, p = 0.03 respectively). The rs7649108 SNP was associated with starch consumption, whereby carriers of the minor allele had a significantly lower starch intake (115.8 vs. 120.9 g starch/day, p = 0.02). No associations were observed between rs4557160, rs13069479 and dietary intake.ConclusionPolymorphisms in the SI gene are associated with dietary intake patterns. Identifying the genetic determinants of dietary intake and food preference may enhance our understanding of excessive caloric intake and obesity, a common risk factor of many chronic conditions.Support or Funding InformationResearch support from Mitacs, Prof. Ahmed El‐Sohemy
Netrin‐1 is a Novel Regulator of Endothelial Function in Diabetes
Authors: Toque Haroldo A. , Fernandez‐Flores Aracely , Mohamed Riyaz , Vilapakkam Punithavathi , Caldwell Ruth B. , Ramesh Ganesan , Caldwell R. William 
Published: November 2023

Netrin‐1, a secreted laminin‐like protein and axon guidance molecule, has been shown to be critically important within the cardiovascular system. Recent studies have revealed it to be pro‐angiogenic, anti‐apoptotic and anti‐inflammatory as well as cardioprotective against myocardial injury in diabetic mice. We examined the role of netrin‐1 in diabetes‐ and high glucose (HG)‐induced vascular endothelial dysfunction using netrin‐1 transgenic (Tg3) and WT mice and bovine aortic endothelial cells (BAECs). Mice rendered diabetic with streptozotocin (STZ) and BAECs were treated with HG (25 mM). Levels of netrin‐1 and its receptor DCC, markers of inflammation, senescence, apoptosis and vascular function were assessed in aortas. Vascular netrin‐1 in WT mice was reduced under diabetic conditions. Aortas from non‐diabetic Tg3 and WT mice showed similar maximum endothelium‐dependent relaxation (MEDR) (83% and 87%, respectively). MEDR was markedly impaired in aorta from diabetic WT mice (51%). This impairment was largely prevented in Tg3 diabetic aorta (MEDR, 70%). Improved vasorelaxation in diabetic Tg3 mice were associated with increased levels of phospho‐ERK1/2 and reduced levels of reactive oxidative species (ROS), mediators of inflammation (NFkβ, COX‐2), cellular senescence (p16INK4A) and apoptosis (cleaved caspase‐3) in comparison to diabetic WT mice. In BAEC, netrin‐1 treatment prevented the HG‐induced decrease in nitric oxide (NO) production and elevation of ROS and apoptosis. In conclusion, overexpression of netrin‐1 prevents diabetes‐induced impairment of vascular endothelium‐dependent relaxation and reduces markers of oxidative stress, senescence, and apopotosis. Netrin‐1 treatment of endothelial cells attenuates HG‐induced impairment of NO synthase function, and elevation of ROS and apoptosis. Enhancement of netrin‐1 levels may be a useful therapeutic means for restoring vascular function in diabetes.Support or Funding InformationSupported by Scientist Development Grant from AHA (13SDG17410007)
H2S‐RELEASING ASPIRIN EXERTS PROTECTIVE EFFECT IN ESOPHAGEAL AND GASTRIC MUCOSAL STRESS‐ASSOCIATED INJURY
Authors: Zayachkivska Oksana , Bula Nazar , Pavlovsky Yaroslav , Gavriluk Elena , Wallace John 
Published: November 2023

Aspirin is one of the widely prescribed antiplatelet and anti‐inflammatory drugs and last data expanded its role into complex biological processes such as cancerogenesis, tissue repair, and aging, despite that well know its effects for peptic ulcer or gastrointestinal (GI) bleeding which can develop even in an achlorhydric environment. Recent extensive research of activities of hydrogen sulfide (H2S) has proven that the addition of H2S‐releasing moiety to the classical non‐steroidal anti‐inflammatory drugs (NSAID) results with GI cytoprotective activity.The objective of this study was to evaluate the effects of novel NSAID‐H2S compound ‐ ATB 340 (Antibe Therapeutics Inc), hydrogen sulfide‐releasing derivative of aspirin (H2S‐aspirin) in esophageal and gastric mucosal defence in a rat model of stress injury.MethodsRats were treated with vehicle (control), classical aspirin (10 mg/kg), ATB‐340 (17,5 mg/kg) with or without being subjected to injury according to the University Ethical Committee Approval (21.05.2014, No 5). The damage of the esophageal mucosa (EM) and gastric mucosa (GM) was estimated via scoring lesion index by histomorphological analysis. Serological levels of VCAM‐1, IL‐6 by ELISA Kits (Cedarlane, Canada) were evaluated.ResultsTreatment by ATB‐340 resulted in protective effect and lower grade of EM & GM lesions in twice by damage index. The basal levels of VCAM‐1, IL‐6 from aspirin‐treated rats and suspected to stress‐injury were higher that of control animal. Pre‐treatment by ATB‐340 exerted an anti‐inflammatory effect by decreasing VCAM‐1 and IL‐6 vs classical aspirin.ConclusionThese results indicate that inhibiting inflammation and improving endothelial functions modulate protective effect of H2S‐aspirin.
Contractile Actions of Hydrogen Sulfide Donors on the Bovine Isolated Iris: Role of Prostaglandins
Authors: Ajelabi Evelyn , Anyikwa Christina , Ly Christine , Chua Cherie , Chua Cheryl , Robinson Jenaye , Mitchell Leah , Opere Catherine , Njie‐Mbye Ya Fatou , Ohia Sunny 
Published: November 2023

We have previously reported that hydrogen sulfide (H2S) donors can relax pre‐contracted, porcine isolated irides, an effect that was dependent upon endogenous production of H2S and prostaglandins, and on the activity of KATP channels (Ohia et al. Curr. Eye Res. 35: 402, 2010). In the present study, we examined the pharmacological actions of H2S donors (NaHS and L‐cysteine) on basal tone in bovine isolated irides. Furthermore, we studied the effect of inhibition of cyclo‐oxygenase (COX) on this response.MethodsIsolated bovine iris muscle strips were set up in an organ bath containing oxygenated Krebs buffer solution maintained at 37°C and gassed with 95% O2: 5% CO2. The muscle strips were set to a resting tension of 0.3 g and longitudinal isometric tension was recorded via a Grass FT03 force‐displacement transducer and analyzed using PolyView Computer Software.ResultsNaHS (1 nM – 10 μM) and L‐cysteine (100 nM – 1 mM) caused a concentration‐dependent contraction of isolated bovine irides yielding EC50 values of 10 nM and 30 μM, respectively. Both COX inhibitors, flurbiprofen (10 μM) and indomethacin (10 μM) abolished the contractile actions of NaHS and L‐cysteine on this tissue.ConclusionsWe conclude that H2S donors can elicit contraction of isolated bovine irides, an effect that is dependent upon the production of endogenous prostaglandins. Based on data reported previously in the porcine isolated irides in which L‐cysteine had no direct contractile action on this tissue, the present finding that L‐cysteine can elicit contractions of bovine isolated irides indicates that a species difference exists in the response of mammalian irides to exogenously applied H2S donors.
NEUROPROTECTIVE ACTIONS OF L‐CYSTEINE AND METH‐ANADAMIDE IN THE BOVINE ISOLATED NEURAL RETINA
Authors: Mitchell‐Bush Leah , Robinson Jenaye , Opere Catherine , Ohia Sunny , Njie‐Mbye Ya Fatou 
Published: November 2023

Evidence from literature suggests that hydrogen sulfide (H2S) and endocannabinoids can protect the central nervous system against glutamate‐induced excitotoxicity and oxidative stress. In the present study, we compared the neuroprotective actions of H2S (using L‐cysteine as a substrate) with that elicited by a cannabinoid (meth‐anandamide) against H2O2‐induced oxidative stress in the isolated bovine retinae.MethodsIsolated neural retinae were pretreated with the H2S substrate L‐cysteine (10 nM ‐ 1 μM) or meth‐anandamide (1 nM–100 nM) for 30 minutes prior to the application of oxidative insult with H2O2 (100 μM) for 10 minutes. Lipid peroxidation was assessed by measuring the levels of 8‐isoprostane in tissues via enzyme immunoassay.ResultsIn the presence of H2O2 (100 μM), there was a 20% increase in 8‐isoprostane levels in isolated retinal slices when compared to untreated controls. Pretreatment of tissues with L‐cysteine or meth‐anandamide blocked the H2O2‐induced increase in 8‐isoprostane levels. For instance, L‐cysteine (10 nM) significantly (P<0.001) reversed H2O2 (100 μM)‐induced elevation of 8‐isoprostane levels in the neural retina. Furthermore, meth‐anandamide (1 nM) completely prevented the H2O2 (100 μM)‐induced increase in the level of the lipid peroxidation product.ConclusionsBoth H2S producing compounds and cannabinoids can protect the bovine neural retina from H2O2‐induced oxidative stress with cannabinoids displaying a higher degree of potency.
Sodium hydrosulfide alleviates cecal ligation and puncture (CLP) ‐ induced sepsis and elevates the regional blood flow in septic shock
Authors: Ahmad Akbar , Szabo Csaba 
Published: November 2023

Cecal ligation and puncture (CLP) induced sepsis is a serious medical condition, caused by a severe systemic infection resulting in a systemic inflammatory response. The aim of the present study was to assess the effect of hydrogen sulfide in sepsis, with special reference to its effect on the modulation of regional blood flow. To this purpose, we infused sodium hydrosulfide (NaHS) (1 mg/kg/h, 3 mg/kg/h or 10 mg/kg/h through the carotid artery) in control rats or rats 24 hours after CLP measured blood flow using fluorescent microspheres. We have also evaluated the effect of hydrogen sulfide on survival and organ function by injecting NaSH (3 mg/kg) intraperitoneally (i.p) after 24 hrs of CLP. We found that in normal control animals, NaHS induced a characteristic redistribution of blood flow, and reduced cardiac, hepatic and renal blood flow in a dose‐dependent fashion. In contrast, we found that, in rats suffering from CLP‐induced septic shock, the regional blood flow was significantly reduced, and infusion of NaSH (1 mg/kg/h and 3 mg/kg/h) significantly increased the blood flow. In other words, the effect of H2S on regional blood flow was dependent on the status of the animals (i.e. a decrease in blood flow in normal controls, but an increase in blood flow in septic animals). After 24 h of CLP, the glomerular function was significantly impaired, as evidenced by markedly increased (over 4‐fold over sham control baseline) blood urea nitrogen and creatinine levels; this increase was also significantly reduced by treatment with NaSH (3 mg/kg i.p). Treatment of the animals with NaSH reduced myeloperoxidase levels (an index of neutrophil infiltration) in heart as well as in lung and malondialdehyde levels (an index of oxidative stress) in heart as well as in liver. Plasma levels of TNF‐alpha and IL‐1beta were increased in septic shock animals, which were attenuated by NaSH. Treatment of NaSH (3 mg/kg i.p) every 6 h after 12 h of CLP improved the survival rate in CLP animals. In summary, delayed treatment with H2S (treatment starting after the CLP‐induced organ injury, inflammation and blood flow redistribution has already ensued) dose‐dependently maintains regional blood flow and exerts protective effects in rat model of CLP induced sepsis.Support or Funding InformationThis work was supported by the National Institutes of Health (R01GM107846) to C.S.
Effect of lipopolysaccharide (LPS)‐induced endotoxemia in mice genetically deficient in either one of the three major hydrogen‐sulfide producing enzymes
Authors: Ahmad Akbar , Gero Domokos , Olah Gabor , Szabo Csaba 
Published: November 2023

Various strategies, targeting the pro‐inflammatory response associated with sepsis have been proposed, without clinical success. We examined the impact of LPS‐induced changes in systemic inflammation, and sulfide expression, metabolism in mice deficient in either one of the three H2S producing enzymes. We injected LPS (10 mg/kg) intraperitoneally (i.p) to wild type (WT) mice, cystathionine‐β‐synthase heterozygous (CBS+/−) mice, cystathionine‐γ‐lyase homozygous (CSE−/−) deficient mice or 3‐mercaptopyruvate sulfurtransferase (3‐MST) mutant mice. After 6 h animals were sacrificed, blood and organs were collected and the following parameters were evaluated: blood urea nitrogen (BUN) and creatinine levels in blood samples, myeloperoxidase (MPO) and malon dialdehyde (MDA) in lung samples, cytokines levels in plasma samples and the expression of the three H2S producing enzymes (CBS, CSE and 3‐MST) in various tissue samples (spleen, lung, liver and kidney) from vehicle and LPS treated CBS+/−, CSE−/−, 3MST mutant mice. We found that LPS markedly impaired the glomerular function, as evidenced by increased (over 4‐fold over baseline) blood urea nitrogen (BUN) and creatinine levels in wild‐type LPS treated mice and CSE & 3MST LPS treated mice. However, CBS+/− LPS treated mice exhibited significantly less BUN levels. Both MPO levels (an index of neutrophil infiltration) and MDA levels (an index of oxidative stress) in lung samples were significantly increased in LPS treated wild‐type mice; these effects were similar in CBS+/−, CSE−/− and 3MST mutant mice. LPS‐induced a significant upregulation of inflammatory cytokines (TNF‐alpha, IL‐1beta, IL‐12 and IFN‐gamma) in the plasma; these effects were comparable in all four animal groups. Finally, the effect of LPS on expression of the three H2S producing enzymes (CBS, CSE and 3MST) in various tissue samples (spleen, lung, liver and kidney) from vehicle and LPS treated WT, CBS+/−, CSE−/− and 3MST mutant mice, in order to test for any compensatory upregulation. We found that CBS expression in liver and kidney samples and 3MST expression in lung samples were significantly high from LPS treated CSE−/− mice compared to wild‐type LPS treated mice. In summary, the observations suggest that deficiency of any single one hydrogen sulfide producing enzymes only modestly affects the outcome of LPS induced endotoxemia, perhaps due to the fact that the H2S production by the remaining other enzymes can compensate for the lack of any single one enzyme.Support or Funding InformationThis work was supported by the National Institutes of Health (R01GM107846) to C.S.
Targeting the sphingosine‐1‐phosphate receptor using virtual screening methods
Authors: Caliman Alisha D , Miao Yinglong , McCammon J Andrew 
Published: November 2023

Sphingosine‐1‐phoshate receptor (S1PR1) is a G protein coupled receptor that regulates the egress of T cells and B cells from secondary lymphoid tissues to the periphery. Given this role, identifying modulators that inhibit the function of S1PR1 and promote retention of T cells is an active area of drug discovery for diseases that are perpetuated by an over‐active immune response. In this study, I used trajectories from conventional and accelerated molecular dynamic simulations to screen S1PR1 for allosteric sites. Afterwards, I screened the allosteric sites and the orthosteric site for potential modulators using high throughput virtual screening (HTVS) and induced fit docking (IFD) algorithms. Top ranking compounds for each site will be tested in vitro.Support or Funding InformationNIH: T32GM007752
Do CHT Inhibitors Constitute a Possible Therapeutic Strategy for Dystonia? Studies with the Novel CHT Inhibitor ML352
Authors: Ennis Elizabeth A , Gresch Paul , Blobaum Anna L , Lindsley Craig W , Dauer William T , Blakely Randy D 
Published: November 2023

Dystonias are a group of disorders characterized by abnormal involuntary contracting of musculature that causes twisting and turning of a patient's body. Though the etiology of each type of dystonia varies, many forms are treated with anticholinergic medications ranging from the use of botulinum toxin to muscarinic receptor antagonists. Although the efficacy of cholinergic treatments is limited by side effects, mechanistic evidence for cholinergic dysfunction along with efficacy of current cholinergic treatments encouraged us to pursue the development of inhibitors of the high affinity choline transporter (CHT, SLC5A7) as a potential treatment of dystonia. CHT transports choline at cholinergic presynaptic terminals, is the rate‐limiting determinate of acetylcholine synthesis, and is subject to activity‐dependent regulation. In vitro brain slice studies demonstrate efficacy of CHT inhibition by the competitive, but highly toxic agent, hemicholinium‐3, in reversing maladaptive plasticities in dystonic mice (Martella et al, 2009; Sciamanna et al, 2012). Through a high‐throughput screen and subsequent chemical diversification effort (Ennis et al, 2015), we identified ML352 as a potent and, specific noncompetitive inhibitor of CHT. Our in vivo studies with CHT heterozygous knock out and overexpressing CHT BAC mice demonstrate that ML352 lethality is dependent on CHT gene dosage, consistent with the transporter as a major site of drug action in vivo. Ongoing studies using microdialysis and behavioral experiments seek to elucidate further in vivo effects of ML352 and its analogs in wild‐type and dystonia mouse models. ML352 provides a novel opportunity to evaluate CHT as a treatment for hypercholinergic disorders.Support or Funding InformationSupported by the Dystonia Medical Research Foundation and the National Institute of Neurological Disorders and Stroke (5R01NS077730 to W.T. Dauer).
Deletion of Endothelial SIRT3 Causes Coronary Microvascular Dysfunction and HFpEF
Authors: He Xiaochen , Zeng Heng , Chen Jian‐xiong 
Published: November 2023

The morbidity of heart failure with preserved ejection fraction (HFpEF) increases with advanced age and diabetes, and is associated with endothelial dysfunction. SIRT3, a mitochondrial NAD+‐dependent deacetylase, declines progressively with aging and in diabetes. However, the role of SIRT3 reduction in HFpEF remains to be elucidated. In the present study, we analyzed the cardiac function and coronary microvascular function in endothelial specific SIRT3 knockout (ECKO) mice and global SIRT3 KO mice, as well as endothelial glycolytic metabolism and angiogenesis in vitro. We found that SIRT3 ECKO mice developed left ventricle (LV) diastolic dysfunction, as evidenced by prolonged isovolumic relaxation time (IVRT) and reduction of coronary flow reserve. Western blot analysis revealed a significant decrease in glycolytic enzyme PFKFB3 in SIRT3 KO‐ECs, accompanied by a dramatic reduction in basal glycolysis, glycolytic reserve and glycolytic capacity. Moreover, SIRT3 KO‐ECs exhibited higher oxygen consumption rate and more prominent production of reactive oxygen species (ROS) than WT‐ECs. SIRT3 KO‐ECs exhibited less potent angiogenic capabilities as indicated by decreased network formation and migration. In contrast, global knockout of SIRT3 in mice resulted in progressive deterioration of LV function, as evidenced by a decrease in ejection fraction and fraction shortening at 12 months of age. SIRT3 KO mice also exhibited reduction of ANP and ERK‐1/2, and increased ROS production, gp91(phox), caspase‐3 and Wnt7 in the heart. In conclusion, we demonstrated that ablation of SIRT3 in ECs caused an HFpEF phenotype with impaired glucose metabolism and angiogenesis. Global SIRT3 KO mice, however, exhibited an HFrEF phenotype. Our data suggest cell‐specific effects of SIRT3 deletion on cardiac function.Support or Funding InformationThis study was supported by National Institutes of Health RO1 HL102042 (Chen).
Late Na+ Current Contributes to Arrhythmogenic Diastolic Ca2+ release in catecholaminergic polymorphic ventricular tachycardia (CPVT)
Authors: Radwanski Przemyslaw , Ho Hsiang‐Ting , Knollmann Björn , Belevych Andriy , Gyorke Sandor 
Published: November 2023

Arrhythmias caused by abnormal impulse formation including CPVT are associated with aberrant diastolic Ca2+ release (DCR) from the sarcoplasmic reticulum. Despite high response of CPVT to agents directly affecting Ca2+ cycling, the incidence of refractory cases is still significant. Surprisingly, these patients often respond to treatment with Na+ channel blockers. However, the relationship between Na+ influx and the arrhythmogenic disturbances in Ca2+ handling (aberrant Na+/Ca2+ signaling) in CPVT remains elusive. To address this issue we used a murine model of cardiac calsequestrin‐associated CPVT. We performed confocal microscopy in isolated ventricular myocytes to assess Ca2+ handling during various pharmacological interventions. Immunocytochemistry experiments were performed to determine the structural underpinnings of Na+/Ca2+ signaling. Late Na+ current (INa) was assessed in whole cell patch‐clamp mode. To monitor arrhythmic activity in vivo surface electrocardiograms were performed before and after intraperitoneal injection of epinephrine (1.5mg/kg) and caffeine (120mg/kg). Immunocytochemistry experiments revealed that neuronal Na+ channels (nNav) colocalize with the ryanodine receptors (RyR2) Ca2+ release channels on the sarcoplasmic reticulum. Isoproterenol (Iso; 100nM) induced late INa in isolated CPVT myocytes which was sensitive to 100nM tetrodotoxin (TTX). Furthermore, nNav blockade with either TTX, riluzole (10μM) or flecainide (2.5 μM) reduced DCR frequency. This antiarrhythmic effect on cellular level translated in decreased ventricular tachycardia (VT) incidence in vivo. On the other hand, nNav augmentation with β‐Pompilidotoxin (β‐PMTX, 40μM) increased both the late INa as well as DCR frequency and VT all of which were reversed by nNav blockade with riluzole or flecainide. These data suggest that Iso‐promoted, nNav‐mediated late INa contributes to the generation of arrhythmogenic DCR in CPVT and can therefore serve as an antiarrhythmic target.Support or Funding InformationThis work was supported by NIH Grants R01‐HL074045, R01‐HL063043 (to S.G.) and K99‐HL127299 (to P.B.R).