bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methylphenidate Does Not Hypersensitize the Rat Heart to Ischemic Injury
Authors: Rorabaugh Boyd R. , Seeley Sarah L. , Stoop Thorne S. , D'Souza Manoranjan S. 
Published: April 2020

BackgroundMethylphenidate is commonly used for the treatment of attention deficit hyperactivity disorder. The cardiovascular safety of methylphenidate has been a subject of debate with some studies indicating that methylphenidate increases the likelihood of experiencing a myocardial infarction. However, it is unknown whether methylphenidate alters the extent of myocardial injury during an ischemic insult. Previous work demonstrated that a history of methamphetamine exposure increases infarct size and postischemic recovery of contractile function in the ischemic heart in a sex‐dependent manner. Methylphenidate and methamphetamine both increase synaptic concentrations of dopamine and norepinephrine, resulting in enhanced adrenergic and dopaminergic signaling. However, it is unknown whether methylphenidate also hypersensitizes the heart to ischemia. The purpose of this study was to determine whether methylphenidate increases the extent of myocardial injury during an ischemic insult.MethodsMale and female rats were treated with methylphenidate (5 mg/kg/day) or saline for 10 days. Hearts were subjected to a 20 min ischemic insult and 2 hours of reperfusion on a Langendorff isolated heart apparatus on day 11. Cardiac contractile function was monitored via an intraventricular balloon, and myocardial injury was assessed by triphenyltetrazolium chloride staining.ResultsMethylphenidate significantly increased locomotor activity in male and female rats. Male hearts had significantly larger infarcts than female hearts, but methylphenidate had no impact on infarct size or postischemic recovery of contractile function in hearts of either sex.ConclusionThese data indicate that methylphenidate does not increase myocardial sensitivity to ischemic injury.Support or Funding InformationThis work was supported by 1R15HL145546 to BRR.
Scarring and Arrhythmia in the Aged Infarcted Heart: The Role of Senescent Fibroblasts
Authors: Baggett Brett , Murphy Kevin , Cao Yueming , Turan Nilufer N. , Lu Yichun , Schofield Lorraine , Kim Tae Yun , Terentyev Dmitry , Sedivy John , Choi Bum-Rak , Koren Gideon 
Published: April 2020

Arrhythmogenic tissue remodeling after myocardial infarction (MI) has been well described in young animals, but how this wound healing process changes with age and leads to increased risk of sudden cardiac death (SCD) post‐MI is not well understood. Cellular senescence is an irreversible cell cycle arrest process which regulates tumor suppression and wound healing, however accumulation of senescent cells in various tissues is thought to drive aging pathology. We hypothesize that with age, persistent cardiac myofibroblast (CMF) senescence promotes persistent inflammation in the scar and thereby facilitating arrhythmogenesis. Using the New Zealand White Rabbit as a model of the aging heart, we show that aged infarcted rabbits display increased peri‐procedural arrhythmic death. Optical mapping studies at 3‐ and 12‐weeks post MI revealed prolonged action potential duration (APD) in the infarct border zone (IBZ) as compared to the remote zone (RZ) in aged rabbits while in young rabbits IBZ’s APD was shorter than RZ’s APD. We also observed slowed conduction and APD alternans at the IBZ which correlated with anchoring of higher frequency ventricular fibrillation in the IBZ of aged rabbits. We show no change in scar size or geometry between young and aged rabbits over the first 12 weeks post‐MI. However, we observed delayed and persistent CMF senescence in the aged scar, even until 12 weeks post‐MI. Using immunohistochemistry and immunofluorescence, we show most senescent cells in the scar are myofibroblasts. We also demonstrate increased expression of senescence‐associated markers in the aged IBZ and scar compared to young, and colocalization of senescent CMFs and inflammatory macrophages in the aged scar and IBZ. Finally, we observe an increase in circulating inflammatory factors from aged rabbit blood samples compared to young, some of which further increased post‐MI. In conclusion, we demonstrate the infarcted aged heart heals differently than young, including delayed and persistent scar CMF senescence, increased VT/VF, and electrophysiological remodeling. Our data support our hypothesis that altered CMF senescence with age induces pathological tissue remodeling post‐MI, underlying the increased risk of SCD.Support or Funding InformationThe authors would like to acknowledge our supporting NIH funding sources, R21 grant 1R21AG049608‐01 and R01 grant R01HL139467
Consumption Pattern of Fruits and Vegetables among solar market garden women’s groups of Kalalé district of Northern Benin
Authors: Valenti Michelle , Alaofè Halimatou 
Published: April 2020

BACKGROUNDAnemia, iron deficiency (ID) and vitamin A deficiency (VAD) continue to be significant public health issues in northern Benin despite the installation of solar market gardens (SMGs), suggesting an urgent need of implementing nutrition programs to benefit the full impact of SMGs. One way to enhance the benefit is to know which fruits and vegetables (F&V) are currently consumed to determine their suitability to promote as a crop.OBJECTIVETo assess the consumption pattern of F&V in the Kalalé district of Northern Benin in order to identify which F&V could be promoted for improving anemia and micronutrients status.METHODSA cross‐sectional survey was conducted among 250 mothers/caregivers aged 19 years and above. Questionnaires were used to assess socio‐demographic characteristics and types of staples foods consumed including the types of F&V consumed and their frequency of consumption. Descriptive analyses were tabulated using STATA version 14.RESULTSSeveral F&V are eaten in the district, but their frequency of daily consumption is low. However, mangoes are abundant during the two fruiting seasons and could be easily accessed by the participating women. Likewise, Moringa oleifera leaves are available all year round and could be incorporated into selected recipes.CONCLUSIONS & IMPLICATIONSMangoes and Moringa oleifera leaves are potential sources of β‐carotene to be promoted on a sustainable basis among SMG women’s groups of Kalalé district of Northern Benin. Additionally, nutrition educational messages should include behavior change campaigns that will make the women see the need for consuming F&V on a daily basis.Support or Funding InformationUniversity of Arizona Mel and Enid Zuckerman College of Public Health Dean’s Annual Fund University of Arizona Graduate & Professional Student Council Travel Grant
Acute blood glucose and vascular endothelial responses to passive heating in individuals with type 2 diabetes
Authors: Behzadi Parya , Gravel Hugo , Ravanelli Nicholas , Gagnon Daniel 
Published: April 2020

IntroductionInsulin resistance and hyperglycemia predispose individuals with type 2 diabetes mellitus (T2DM) to endothelial dysfunction and a greater risk of cardiovascular diseases. Numerous animal studies suggest that heat exposure improves glucose control and human studies suggest that it improves markers of vascular health. However, the physiological responses to heat exposure remain understudied in individuals with T2DM, particularly within a therapeutic context.ObjectiveTo characterize blood glucose and vascular endothelial responses to heat exposure in T2DM and determine if heating acutely improves glucose control and endothelial function in this population.MethodsOn separate randomized days, six adults (2 males/4 females, 60 ± 12 years) with T2DM (≥1 year, HbA1c: 7.0 ± 0.5%, fasting glucose: 7.79 ± 1.13 mmol/L) were immersed in control (34°C, 90 minutes) or hot (40–41°C, core temperature ≥38.5°C for 60 minutes) water. Participants were fasted (12 hours) and withheld anti‐diabetic medication (≥24 hours). Blood glucose and insulin as well as brachial artery shear rates were measured at baseline, during immersion and 45–60 minutes after immersion. Brachial artery flow‐mediated dilation (FMD) was measured at baseline and 45 minutes after immersion. Blood glucose control was evaluated during an oral glucose tolerance test (OGTT, 75 g) 60 minutes after immersion. Core (Tcore, rectal) and mean skin (Tskin) temperatures, heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressures were measured throughout the protocol.ResultsCompared to control, hot water immersion increased Tcore (+1.44°C [1.05, 1.83], P<0.01), Tskin (+2.36°C [1.21, 3.51], P<0.01), HR (+35 bpm [26, 43], P<0.01), and decreased DBP (−7 mmHg [−2, −13], P<0.01) and SBP (−9 mmHg [−1, −16], P=0.03). Hot water immersion increased antegrade (+71 s−1 [35, 107], P<0.01) and decreased retrograde (−15 s−1 [0.9, 3], P=0.06) shear rates. Nonetheless, FMD was unchanged during both control (−0.74% [−4.33, 2.86], P=0.81) and hot (−1.93% [−5.53, 1.66], P=0.30) water immersion. Blood glucose decreased progressively throughout the control protocol (−1.3 mmol/L [−0.8, −1.9], P<0.01), whereas hot water immersion attenuated this decrease (+0.1 mmol/L [−0.5, +0.6], P=0.93). Hot water immersion did not alter glucose (P=0.17) and insulin (P=0.99) area under the curve during the OGTT.ConclusionThese preliminary results suggest that the physiological responses associated with heat exposure do not translate into acute improvements in blood glucose control or brachial artery endothelial function in individuals with T2DM.Support or Funding InformationCardiometabolic Health, Diabetes and Obesity Research Network and Diabetes Quebec.
Glutamine Synthetase and Cytochrome P‐4502E1 Characterize Metabolic Zonation in Human Liver: Immunohistochemical Study
Authors: Mak Ki Mark 
Published: April 2020

Hepatic metabolic zonation endows metabolic homeostasis and proper functioning of the liver under various physiological conditions. The zonation reflects the heterogeneity of gene expression and functions of hepatocytes along the centro‐portal axis of the liver lobule. The Wnt/ß‐catenin signaling pathway is the master regulator of hepatic zonation. The pathway maintains the metabolic zonation of glutamine synthetase (GS) and cytochrome P‐4502E1 (2E1) —among others—in the centrilobular parenchyma. GS detoxifies ammonia entering the liver as well as serves as an immunohistological marker of perivenous hepatocytes that make up the first three cell layers around the central vein. 2E1 mediates metabolism of xenobiotics and has a broader centrilobular expression than that of GS. While the zonation of GS and 2E1 has been documented in animal models, the phenomenon remains to be evaluated in human liver. This study assessed expression of GS and 2E1 in human cadaveric livers by immunohistochemistry. Ten livers of cadavers (mean age, 79.9 years) with minimal fibrotic changes were studied. Consecutive paraffin liver sections were stained with a polyclonal GS antibody or 2E1 antibody using an immunoperoxidase method. The central vein was defined as a hepatic vein located at the center of the classic liver lobule and showed a cross‐sectional diameter not exceeding 150 μm. In each liver, five to six veins were examined for the distribution of GS+ hepatocytes in the centrilobular area. In most cases, GS+ hepatocytes were arranged in a band of 1 to 3 cells wide in the perivenous area around the central veins (perivenous cells). In some instances, GS staining was observed in hepatocytes beyond the perivenous area (recorded as non‐perivenous cells). Midlobular and periportal hepatocytes lacked GS staining. Expressed as per central vein, counts of perivenous GS+ cells were 14.9 ± 2.2 and non‐perivenous cells were 5.6 ± 1.8. The mean 2E1 zonal score was 1.35 ± 0.35. Total GS+ cell numbers (perivenous plus non‐perivenous) were found to correlate with 2E1 zonal scores (P > 0.05, N = 10).ConclusionsExpression of GS and 2E1 characterizes the metabolic zonation in the liver of aged cadavers, in accordance with the findings of animal studies. The correlation of GS with 2E1 expression suggests a link between the hepatic zonation of GS and 2E1, which is consistent with the notion that the zonation is mediated by the Wnt/ß‐catenin signaling pathway.
Cadherin‐3 and Catenin‐α2 are novel MMP‐12 substrates
Authors: Chalise Upendra , Lindsey Merry L. 
Published: April 2020

Adverse cardiac remodeling after myocardial infarction (MI) is a major cause of heart failure. Degradation of the existing extracellular matrix (ECM) and subsequent formation of a new ECM scar are prominent components of cardiac remodeling. Matrix metalloproteinases (MMPs) increase after MI to dictate the degradation component. MMP‐12 inhibition after MI worsens dilation of the left ventricle by increasing its wall thinning, suggesting a possible protective role for MMP‐12 in MI remodeling. We hypothesized that identifying MMP‐12 substrates could provide mechanistic insight into MI roles. We used the Mouse Heart Attack Research Tool 1.0 (mHART 1.0) database and performed regression analysis to identify ECM genes that correlated with MMP‐12 expression. Of the 83 ECM genes compared to MMP‐12, 41 showed significant regressions (all p<0.05). This indicates a strong relationship between ECM breakdown after MI and MMP‐12. Synaptotagmin‐1, Contactin‐1, MMP‐10, MMP‐13, and Catenin‐α2 were the top 5 genes with significant positive correlation (Pearson coefficient r>0.99 and p<0.0001 for all). By Enrichr analysis for transcription factor pathway exploration, Yap1 signaling had a top combined score of 9.37 and p‐value 0.0033, indicating the upregulation of HIPPO signaling as the most enriched pathway. Catenin‐α2(Ctnna2), Cadherin‐1 (Cdh1), and Cadherin‐3 (Cdh3) were the three genes linked to Yap1‐ Hippo signaling. By substrate cleavage assay using 0.1 μg MMP‐12 enzyme to 0.5 μg substrate, Cdh3 and Ctnna2 but not Cdh1 were identified as novel MMP‐12 substrates. Cdh3 and Ctnna2 showed robust cleavage at 15 min, and Ctnna2 was completely processed by 3h. Our combined results reveal that MMP‐12 actions in MI remodeling could be attributed in part to Cdh3 and Ctnna2 proteolytic processing.Support or Funding InformationWe acknowledge funding from the National Institutes of Health under Award Numbers HL075360, HL129823, and HL137319, and the Biomedical Laboratory Research and Development Service of the Veterans Affairs Office of Research and Development under Award Numbers 5I01BX000505.
a‐arrestin ARRDC3 is a Multifunctional Adaptor That Regulates G Protein‐Coupled Receptor Signaling and Breast Cancer Invasion
Authors: Pan Wen-An , Arakaki Aleena , Wedegaertner Helen , Kufareva Irina , Trejo JoAnn 
Published: April 2020

Aberrant G protein‐coupled receptor (GPCR) signaling drives cancer initiation and progression, but the mechanism underlying dysregulated GPCR signaling is unknown and represents a major gap in knowledge. Protease‐activated receptor‐1 (PAR1) is proteolytically activated and requires lysosomal degradation for signal termination. PAR1 overexpression correlates with high tumor grade and poor prognosis in breast cancer patients. Increased PAR1 expression results from altered receptor trafficking, which causes persistent signaling and increased invasiveness. We recently discovered that loss of the tumor suppressor α‐arrestin domain‐containing protein‐3 (ARRDC3) is responsible for dysregulated PAR1 trafficking, persistent signaling and breast cancer invasion. This work establishes for the first time a link between ARRDC3 and GPCR dysfunction in cancer. However, it is not known how ARRDC3 alters the dynamics of PAR1 signaling via receptor trafficking or if other determinants are important. We found that ARRDC3 regulates PAR1‐induced non‐canonical endosomal p38α MAPK signaling, but not PAR1‐rapid initiation of Gα12/13‐RhoA signaling from the plasma membrane. Interestingly, ARRDC3 interacts with NEDD4 ubiquitin E3 ligases via C‐terminal PPXY motifs, which is required for agonist‐induced PAR1 degradation, but not essential for regulation of p38α MAPK signaling. However, deletion of the C‐terminus tail abrogated both processes, suggesting that an additional determinant within the C‐terminustail distinct from the PPxY motifs is also important for mediating ARRDC3 function. In addition, PAR1‐stimulated invasion is dependent on p38a MAPK and regulated by ARRDC3, which requires the C‐terminal domain but is only partially suppressed by ARRDC3 PPXY mutant. We further discovered a novel phosphorylated Ser/Thr cluster in the C‐terminus that is critical for ARRDC3 function including modulation of ARRDC3 homo‐oligomerization and basal conformation. Meta‐analysis of breast cancer patients indicates that ARRDC3 and genes involved in PAR1‐activated p38α MAPK are associated with poor prognosis in the aggressive subtype of breast cancer patients. Currently, we are determining the molecular mechanisms by which phospho‐Ser/Thr cluster effects ARRDC3 conformation and function. In conclusion, this work has provided critical insight that improves our understanding of ARRDC3 function in spatiotemporal regulation of GPCRs signaling in invasive breast carcinoma, which may provide new therapeutic options for treating metastatic breast cancer.Support or Funding InformationNIH/NIGMS R35 GM127121
Myeloid mineralocorticoid receptor activation alters metabolism in HFD‐salt fed mice
Authors: Lefranc Clara , Gabarre Paul , Genty Marie , Ramirez Roberto Palacios , Feraco Alessandra , Caprio Massimiliano , Jaisser Frederic 
Published: April 2020

Context and ObjectivesIn obese mice and patients, mineralocorticoid receptor (MR) activation has deleterious consequences on metabolic and cardiovascular parameters. In mice, adipose tissue MR triggers mitochondrial and vascular dysfunction. Adipocyte MR activation induces metabolic and vascular dysfunction in a context of obesity, however, obese adipose tissue is also infiltrated with macrophages, which are capable of expressing MR. Thus, we hypothesised that macrophage MR could also be responsible for metabolic and cardiovascular complications in high‐fat high‐salt diet‐fed mice.MethodsWe fed myeloid cell‐specific MR knock‐out male and female mice (My‐MRKO) with a 6‐week high fat – high salt diet (60% kcal from fat, 1.2% salt in drinking water) and studied weight gain, whole body and specific organs composition by nuclear magnetic resonance and insulin sensitivity to explore the metabolic phenotype. Blood pressure measurements by plethysmography and vascular reactivity studies by wire myography were also performed to characterise the cardiovascular phenotype.ResultsMy‐MRKO male mice under high fat – high salt diet displayed reduced weight (37.8 g [interquartile range 34.1–40.8] vs 42.5 g [39.5–45.2]; P = 0.0128), preserved muscle mass (61.5 % [55.8–63.3] vs 56.8 % [54.1–58.5]; P = 0.0337) and a strong tendency to decreased fat mass (26.1 % [23.7–33.9] vs 31.7 % [27.1–35.4]; P = 0.0728). Moreover, liver fat content at sacrifice was decreased (5.8 % [2.1–9.1] vs 9.3 % [5.9–13.4]; P = 0.0491). Those effects were not observed in female mice. Fasting glycaemia was decreased in male My‐MRKO mice (9.2 mmol/L [6.4–12.8] vs 13.2 mmol/L [10.4–16.1]; P = 0.0005) and insulin resistance was decreased in both gender (area under curve 9915 [9398–10043] vs 11550 [9795–12848]; P = 0.0458 in males, 8291 [7812–8884] vs 9544 [8918–9735]; P = 0.0177 in females), as assessed by an insulin tolerance test. A clear effect was observed on blood pressure only in female mice (blood pressure 96 mmHg [94–97] vs 106 mmHg [104–109]; P = 0.0004), whereas there was no modification in mesenteric arteries vascular reactivity in both gender.ConclusionsThus, our findings show that myeloid cell‐MR regulates systemic metabolic parameters, highlighting a new role in obesity and its associated complications for MR expressed in myeloid cells.Support or Funding InformationSorbonne Université, Inserm, CARMMA‐RHU
Design of first in class bitopic ligands targeting the sodium binding pocket in opioid receptors
Authors: Faouzi Abdelfattah , Zaidi Saheem , Che Tao , Kormos Chad , Zhang Tiffany , Madasu Manish , Eans Shainnel , Simons Chloe , Pan Ying-Xian , McLaughlin Jay , Carroll Ivy , Hassani Ream Al , Roth Bryan , Katritch Vsevolod , Majumdar Susruta 
Published: April 2020

Opioid agonists have been used in the field of pain management for centuries, but are considered a major public health concern, especially in the US. One of the biggest challenges consists in understanding the ability to target specifically the different subtypes of opioid receptors and to trigger a specific functional response correlating with an in vivo analgesic response devoid of side‐effects.These opioid receptors are part of the GPCRs family, which is known to have common features across different subfamilies. One important feature of these receptors is the presence of allosteric binding pockets, which is progressively gaining momentum as a novel target for current therapeutic strategies. We hypothesized that targeting an allosteric site could potentially allow for receptor functional selectivity, helping to reduce the overall side effects profile. One site, in particular, known as the Na+ binding pocket, is known to play a key role in GPCR function and is thought to be the center of the functional mechanism, with several bias switches characterized in the pocket residues (Katritch et al., Trends Biochem Sci. 2014).Here we report structure‐based rational drug design of bitopic ligands targeting the Na+ pocket of mu (MOR) and kappa opioid receptors (KOR). Our designed bitopics show high affinity, subtype selectivity, G‐protein bias and analgesic actions in mice. Mutations in Na+ binding pocket diminished functional potency validating allosteric site targeting. Together, results suggest the possibility of achieving subtype selectivity and identification of an additional subpocket in both MOR and KOR to reduce βarrestin‐2 recruitment by targeting an allosteric pocket in the opioid receptors. The highly conserved constitution of the Na+ binding pocket opens the opportunity for rational discovery of new GPCR modulators with desired functional, and potentially therapeutic profile for opioids as well as other class A GPCRs.Support or Funding InformationWe gratefully acknowledge the financial support from Faculty Research Incentive Fund, NIDA, NIAAA and US department of defense. We also would like to thank the Philippe Foundation for their financial support.