bluuebunny/crossref_metadata_2025_split huggingface dataset:
GPR183 and GPR19 Activation Improves Pancreatic Alpha Cell‐Induced Glucose Homeostasis
Authors: Rossiter Jackie L. , Yosten Gina L.C. , Kolar Grant R. 
Published: April 2020

Diabetes mellitus (DM) is characterised by pancreatic islet failure and dysregulation. The pancreatic islet is comprised of three primary cell types: alpha, beta and delta cells. Pancreatic beta cell destruction is responsible for the onset of classical symptoms of DM consequent to loss of endogenous insulin production and has been the subject of decades of research effort. The mechanisms underlying alpha cell dysfunction are less well understood, but no less important. Alpha cell dysfunction contributes to counter regulatory failure and predisposes to severe hypoglycemia, a disabling and potentially fatal diabetic complication. Thus, it is critical to identify new targets for the treatment of alpha cell dysfunction. Using a PCR‐based screen of AlphaTC1‐9 cells, we identified G‐protein coupled receptors 183 and 19 as highly expressed in alpha cells. G‐protein coupled receptor 183 (GPR183, also known as EB12) is the receptor for the potent GPR183 agonist 7alpha 25‐dihydroxycholesterol. GPR183 expression is increased in human pancreatic beta cells and GPR183 activation by 7alpha 25‐dihydroxycholesterol promotes both insulin transcription and release in these beta cells. G‐protein coupled receptor 19 (GPR19) is the receptor for adropin, a small peptide which plays roles in metabolism and energy homeostasis. Circulating adropin acts on the liver to enhance Insulin receptor substrate (IRS) sensitivity and reduce hepatic glucose release. Adropin levels are reduced in obesity, and adropin administration to diet‐induced‐obese mice reduces insulin resistance and lowers fasting blood glucose. The effect of adropin on pancreatic alpha cell function had not been examined prior to this study. We hypothesize that GPR183 and GPR19 act in the pancreatic alpha cell to facilitate glucose homeostasis. To test this hypothesis, Alpha TC1‐9 cells were treated with GPR183 agonist, 7alpha 25‐dihydroxycholesterol, at 1nM, 10nM, and 100nM, or GPR19 agonist, adropin, at 1nM, 3nM, or 9nM. AlphaTC1‐9 were treated with agonists unstimulated, stimulated for 1 hour at 25mM glucose (HG) and treated at 5.5mM glucose (NG), or stimulated for 1 hour at 25mM glucose and treated at 2.2mM glucose (LG). Treatment with the GPR183 agonist 7alpha 25‐dihydroxycholesterol increased proglucagon transcript and reduced GPR183 and GPPR19 transcript in alphaTC1‐9 cells. Treatment with adropin had no effect on proglucagon transcript and robustly increased GPR183 transcript. These results suggest GPR183 and GPR19 as novel therapeutic targets to reduce the incidence of hypoglycemia in DM.Support or Funding InformationNIDDK
BCL6 is Upregulated in Perivascular Adipose Tissue (PVAT) in Western Diet‐Induced Obesity‐Related Hypertension in Female Rats
Authors: Maddie Nicole Marie , Persand Dhandevi , Carrillo-Sepulveda Maria Alicia 
Published: April 2020

BackgroundOverconsumption of a Western Diet (WD), characterized by high‐fat and high sugar, frequently results in obesity‐related hypertension. During obesity, PVAT switches from a vasculo‐protective to an inflammatory phenotype contributing to vascular dysfunction and hypertension. The transcriptional repressor B‐Cell Lymphoma 6 (BCL6) has recently emerged as a negative regulator of adiposity. However, whether obesity alters BCL6 levels in the PVAT remains unknown. We hypothesized that WD upregulates BCL6 in PVAT resulting in dysfunctional PVAT‐induced hypertension.MethodsRecently, our lab established a model of WD‐induced obesity in female rats. Eight‐week‐old female Wistar rats were randomized into two experimental groups: Control group (n=6) received a regular chow diet (5% fat, 48.7% carbohydrate [3.2% sucrose], 24.1% protein) while the WD group (n=7) received a WD (21% fat, 50% carbohydrate [34% sucrose], 20% protein), for 20 weeks. Cardiovascular parameters, including direct blood pressure and endothelium‐independent vasodilation measurements, were assessed by carotid catheterization and cumulative concentration curve for sodium nitroprusside (SNP) by using a wire myography, respectively. Metabolic parameters were obtained by biochemical assays and homeostatic model of insulin resistance (HOMA‐IR) calculation. At terminal experiments, thoracic aorta and PVAT were collected for molecular and histological analysis.ResultsAs expected, the WD group exhibited exacerbated cardiometabolic alterations including increased body weight (412 ± 22 vs. 299 ± 5 g, p<0.01), serum triglycerides (184.2±7.44 vs. 51.5±4.9 mg/dl, p<0.001), nonesterified free fatty acid (0.98±0.05 vs. 0.05±0.02 mM, p<0.05) and insulin resistance (HOMA‐IR: 10.22 ± 1.45 vs. 1.43 ± 0.03 a.u, p<0.05), compared to controls. WD caused an increase in systolic blood pressure (147.3±7 vs. 122.7±5.29 mmHg controls, p<0.01), along with increased heart rate (381.91±11 vs. 334.26±22 bpm controls, p<0.05). SNP‐induced relaxation in aortas was reduced in the WD group (Emax: 78.55±4% vs. 96.88±6% controls, p<0.01), indicating that the decreased vasodilation caused by a WD involves vascular smooth muscle cell dysfunction. More importantly, these vascular complications were directly associated with robust phenotypic changes in aortic PVAT, which included switches from a brown‐like to a white‐like adipose tissue as evidenced by enlarged adipocytes, 60% reduction on mitochondrial density (p<0.01) and increased expression of inflammatory marker MCP‐1 (2.5‐fold increased, p<0.001) compared to controls. Strikingly, BCL6 expression was markedly elevated in PVAT from the WD group (2.1‐fold increased, p<0.05).ConclusionOur results show for the first time that BCL6 is upregulated in the aortic PVAT under obesogenic conditions. BCL6 has the potential to be a therapeutic target for obesity‐associated vascular dysfunction and hypertension.Support or Funding InformationNIH
Aortic Banding and Low‐Intensity Exercise Training do not Alter Autophagy in a Yucatan Mini‐Swine Model of Pressure Overload‐Induced Heart Failure
Authors: Silva Kleiton Augusto Santos , Thorne Pamela , Ivey Jan , Emter Craig A. 
Published: April 2020

The autophagy‐lysosome system is an essential intracellular proteolytic process mediating recycling of dysfunctional proteins and organelles. This process is important to cellular renovation, and activation of autophagy by exercise training (ET) is considered essential to the maintenance of cellular vitality. However, the implications of chronic low‐intensity ET on autophagic function in an experimental setting of heart failure (HF) remains unclear. The purpose of this study was to determine if autophagy contributes to cardiovascular dysfunction that is treatable by ET in a pre‐clinical model of pressure overload‐induced HF. We hypothesized ET would prevent aortic banding‐induced decreases in autophagy in the heart, coronary vasculature, and skeletal muscle. Male Yucatan mini‐swine (29–32 kg; 8 mo‐old) were assigned to the following groups (6–7 pigs/groups): control (CON), heart failure (HF), heart failure low‐intensity continuous ET (HF‐CT), and heart failure low‐intensity interval ET (HF‐IT). Chronic pressure overload was induced by an aortic band placed on the ascending aorta proximal to the brachiocephalic artery. Two months post‐surgery and after the development of pathological hypertrophic remodeling, animals began treadmill ET 3 times/week at 55 minutes/session for 17 weeks. Autophagic markers measured by protein level of LC3B (a marker of autophagosome formation), p62 (autophagosome cargo receptor) and Beclin 1 (regulation of autophagy initiation), were assessed in the left ventricle (LV), right ventricle (RV), left circumflex artery (LCX), right coronary artery (RCA), deltoid, and long head of the triceps (TLH). We found no changes in autophagic markers (LC3B‐I, LC3B‐II, LC3B‐II/I ratio, p62, and Beclin 1) in LV, RV, LCX, RCA, deltoid, and TLH when comparing HF group with CON group (p>0.05). Similarly, ET of any intensity did not alter autophagic markers in LV, RV, LCX, RCA, deltoid, and TLH compared to CON and HF groups (p>0.05). Contrary to our hypothesis, protein levels of a number of different well‐established markers of autophagy were not decreased in the HF group. Further, our results do not demonstrate any change in this important cellular recycling mechanism following chronic low‐intensity ET. Although activation of autophagy is considered a positive adaptation of ET in a setting of physiological health, these data suggest autophagy may not be a mechanism by which ET of an intensity tolerable to a heart failure patient improves cardiovascular and skeletal muscle health in a pre‐clinical model of pressure overload‐induced HF.Support or Funding InformationCraig A. Emter – NIH/NHLBI R01 HL112998, and Kleiton A. S. Silva – AHA: 18POST33960472
Transmural Variation of Collagen Orientation and Structure Distributions in the Right Pulmonary Arterial Wall
Authors: Pursell Erica , Valdez-Jasso Daniela 
Published: April 2020

Pulmonary arterial hypertension (PAH) is a disease characterized by elevated blood pressure (mean pulmonary arterial pressure above 25 mmHg. Remodeling of pulmonary arteries due to this elevated blood pressure compromises their normal physiological function. Our previous work showed that the right pulmonary artery significantly stiffens circumferentially in PAH and collagen fibers become engaged and significantly aligned in the medial layer (Pursell et al 2016). To better understand the changes in tissue mechanical response, here we explore the distributions of collagen orientation and tortuosity through the vessel wall.MethodsTo induce PAH, four male Sprague‐Dawley rats were injected with 60 mg/kg monocrotaline. Once PAH was established (4 weeks post‐injection), pulmonary arteries were harvested, and collagen imaged via multiphoton microscopy. A custom MATLAB code was then used to determine collagen fiber orientation and tortuosity.ResultsMPM images of collagen fibers from the intima, media, and adventitia of normotensive and hypertensive rat RPAs were traced with our custom MATLAB code. In the hypertensive animals, fiber direction and tortuosity varied more between vascular wall layers than those of normotensive animals.ConclusionsWhile our previous study only examined the medial layer, this study determined that fiber distribution varies throughout the vessel wall. This will significantly affect the mechanics or behavior of pulmonary vessels. Therefore, future studies will need to incorporate collagen structures from multiple vessel layers to better understand the relationship between vascular remodeling and mechanics.
Exosome‐associated ELAVL1 adversely affects cardiac macrophage‐fibroblast crosstalk in diabetes
Authors: Krishnamurthy Prasanna , Govindappa Prem , Patil Mallikarjun 
Published: April 2020

BackgroundMacrophage dysfunction, inflammation and excessive fibroblast activation has been implicated in the pathogenesis of diabetes‐associated heart disease. However, the paracrine mechanisms are not completely understood. We sought to unravel the influence of diabetes on exosome (Exo) transfer of Human antigen R (HuR or ELAVL1, an mRNA stabilizing protein) and its implications on cardiac fibrosis and dysfunction.Methods and ResultsWe evaluated the invitro and invivo effects of macrophage cellular‐ and exosome‐HuR or its deficiency on paracrine mechanisms of diabetic milieu‐induced inflammatory and fibrosis‐related signaling. Human failing hearts show higher HuR levels as compared to non‐failing hearts. Diabetic milieu (db/db mice) show increase in HuR expression in cardiac‐ and cultured bone marrow derived‐macrophages (BMMac). High glucose (HG, 30mM) stimulates HuR nuclear‐to‐cytoplasmic translocation and transfer of HuR mRNA and protein into exosomes. PKC‐delta inhibition blocks HG‐induced HuR translocation. Exosome from macrophages exposed to diabetic milieu (HG or db/db mice) significantly increases proinflammatory and profibrogenic responses in fibroblast (invitro) or cardiac fibrosis in mice. Exo‐HuR deficiency (HuR knockdown in macrophage) abrogates the above effects. In diabetic mice, macrophage depletion followed by reconstitution with HuR‐deficient‐BMMac decreases ANG II‐induced cardiac fibrosis and improves LV dysfunction as compared to BMMacWT administered mice.ConclusionsTo the best of our knowledge, this is the first study to demonstrate that diabetes‐mediated increase in BMMac‐HuR expression, its cytoplasmic translocation and exosome transfer activates fibrogenesis signaling invitro and invivo, and HuR deficiency attenuates these deleterious effects. The data suggests that HuR might be targeted to alleviate macrophage dysfunction and pathological fibrosis in diabetes mellitus.Support or Funding InformationNational Institutes of Health (NIH) grants HL116729 (to P.K.), HL138023 (to P.K. and J.Z.), and American Heart Association Grant‐in‐aid GRNT 25860041 (to P.K.) and Transformational Project Award 19TPA34850100 (to P.K.).
Identifying the Substrate Interactions of KDAC7
Authors: Mohammed Hajjia S. , Nichols Kyara A. , Toro Tasha B. , Watt Terry J. 
Published: April 2020

Protein post‐translational modifications are chemical adaptations that take place in the human body to control behavior of proteins. The acetylation of lysine is one type of protein post‐translational modification. Lysine deacetylases (KDACs or HDACs), are enzymes that help regulate proteins by reversing this modification. It has been shown that KDAC7 is essential in many biological processes, but KDAC7 has no identified substrate proteins. Therefore, better understanding of KDAC7 substrate preferences could lead to the improved treatment of diseases. Using a gain‐of‐function variant of KDAC7 that significantly increases enzyme activity, we have identified several possible substrates using peptides derived from identified acetylated proteins. Molecular dynamics simulations suggest possible important interactions between these peptides and the enzyme. We are also examining the effect of the second, non‐catalytic domain of KDAC7 on substrate preferences and overall activity. Possible substrates identified by these experiments provide leads for cell‐based assays to determine in vivo substrates and/or binding partners. This work provides a greater understanding of how KDAC7 interacts with potential substrate proteins and the biological activity of the enzyme.Support or Funding InformationNIH TL4GM118968, UL1GM118967, 5G12MD007595, and R15GM129682; NSF CHE 1625993 and MCB 1817358; U. S. Army Research Laboratory and the U. S. Army Research Office W911NF1810450; and the Louisiana Cancer Research Consortium.
Non‐coding RNA modulates cardiovascular adverse effects of anthracycline chemotherapeutic agent
Authors: Krishnamurthy Prasanna , Henderson John , Patil Mallikarjun 
Published: April 2020

IntroductionNon‐coding RNA regulate numerous pathophysiological processes involved in cardiac health and disease. microRNA‐377 dysregulation has been implicated in cardiac dysfunction and remodeling.ObjectivesWe evaluated its role in chemotherapy agent (doxorubicin, DOX)‐induced cardiotoxicity, specifically in DOX‐induced cardiomyocyte (CMs) stress and endothelial dysfunction.MethodsmiR‐377 expression and its targets were evaluated in human and mouse ischemic‐myocardial tissue by qRT‐PCR and RNA‐sequencing. We determined miR‐377 effect on Dox‐induced cardiomyocyte cell death, oxidative stress gene and cardiac pathology.ResultsHuman cardiac biopsies from HF patients show significant increase in miR‐377 expression in comparison to non‐failing hearts. Cardiac ischemia‐reperfusion (I/R) injury in mice increases myocardial miR‐377 expression. Furthermore, single cell suspension of mouse ischemic heart and qPCR analysis show a robust increase (~13 fold) in miR‐377 expression specifically in the cardiomyocyte. Following DOX‐induced cellular stress, miR‐377 expression in CMs was elevated, and inhibition of miR‐377 attenuates DOX‐induced cell death and inflammatory response in CMs in vitro. RNA‐sequencing data suggests miR‐377 regulates numerous genes involved in cell survival and growth in cardiomyocytes. Furthermore, transfection of miR‐377 mimics in HUVECs significantly inhibits VEGF induced migration and vascular tube formation. In addition, proteome profile of human CD34+ cells transfected with miR‐377 mimics show significant decrease in numerous proangiogenic proteins as compared to nonspecific control transfected cells. Interestingly, anti‐miR‐377 injection in mice after doxorubicin administration shows increase in left ventricular wall thickness and reduction in LV chamber size.ConclusionsThese findings suggest that doxorubicin‐induced cardiotoxicity is associated with an increase in miR‐377 expression in the myocardium and that miR‐377 overexpression is detrimental to cardiomyocyte viability and endothelial cell function. Furthermore, in vitro, inhibition of miR‐377 was protective against DOX‐induced apoptosis, and attenuated the expression of anti‐oxidant genes. Therefore, targeting miR‐377 might protect against DOX‐induced cardiotoxicity.Support or Funding InformationNational Institutes of Health (NIH) grants HL116729 (to P.K.), HL138023 (to P.K. and J.Z.), and American Heart Association Grant‐in‐aid GRNT 25860041 (to P.K.) and Transformational Project Award 19TPA34850100 (to P.K.)
Greenhouse Gas Concentrations Driven by Microbial Community Structure in Boston Groundwater Wells
Authors: Momyer Victoria , Al-Haj Alia , Angell John , Fulweiler Robinson W. 
Published: April 2020

Methane is a powerful greenhouse gas with a global warming potential 34 times that of carbon dioxide. Recent work has demonstrated high methane concentrations in groundwater wells. While previous research has focused on anthropogenic sources of methane in groundwater wells, it is also possible that methane is produced in situ via archaea. Here we determine the source(s) of the high methane concentrations in groundwater wells in Boston, MA. We also assess the groundwater well methanogen and methanotroph community. To do so, we collected gas, water, and DNA samples from nine groundwater wells throughout the city between 2017 and 2019. Methane, carbon dioxide, and nitrous oxide concentrations were determined using gas chromatography. DNA samples were extracted, replicated with archaeal and bacterial 16S primers, and sequenced using Illumina Mi‐Seq High Output DNA Sequencing. We found that 27.9% of our measurements could be attributed to natural gas leaks near the groundwater wells (>2.5% methane). In groundwater wells with no natural gas leaks, methane concentrations were negatively correlated with dissolved oxygen concentrations (r = −0.5480; p = 0.001416) and positively correlated with salinity (r = 0.5466; p = 0.001465). Additional data on the groundwater well microbial community is forthcoming and will also be presented. Overall, this study provides insight into how various environmental conditions such as salinity, dissolved oxygen, and distance to seawater impacts methanogen and methanotroph populations.Support or Funding InformationSupport and/or Funding provided by Boston University Undergraduate Research Opportunities Program, Boston University Kilachand Honors College, and the American Society for Biochemistry and Molecular Biology.
STAT3 is essential for proper limb skeletal development
Authors: Rigueur Diana 
Published: April 2020

The Interleukin‐6/STAT3 (IL‐6/STAT3) signaling pathway has been well investigated in the development of the immune system and in disease. From autoimmune disorders, cancers, rheumatoid, and osteoarthritis, STAT3 gain‐of‐function and loss‐of‐function studies have shown that in humans, its regulation is imperative for control of disease. However, the precise role that STAT3 and its downstream effectors play in the formation, maintenance, and disease of the skeleton, remain understudied. Our recent work shows that STAT3 is imperative for multiple aspects of limb skeletal development. Through whole‐mount skeletal preparations, X‐ray micrographs, and histology, conditional loss of STAT3 in limb, via the Prx1‐Cre driver, show that STAT3 mediates proper cartilage, bone, tendon, and ligament formation. Moreover, loss of STAT3 results in severe bending and twisting of the fore and hind limbs, as well as abnormal tendon and ligament attachments. Furthermore, loss of STAT3 shows forelimb regional specificity of ectopic bone formation. Additional investigation of STAT3 mediated downstream effectors can identify a mechanism involved in proper cartilage and bone formation, as well as tendon and ligament‐to‐bone integration. Fundamental understanding of the role STAT3‐mediated signaling plays in skeletal formation may identify future therapeutics for regenerative medicine in tendon/ligament bone repair.Support or Funding InformationNIH R01 80094
Developing an efficient ocular delivery system for the hydrogen sulfide releasing compound, diallyl trisulfide
Authors: Singh Neetu , Opere Catherine , Singh Somnath 
Published: April 2020

PurposeAlthough hydrogen sulfide (H2S) exhibits ocular hypotensive and retinal neuroprotective actions (Ohia et al., JOPT, 34:61,2018), its ocular delivery is challenging. Diallyl trisulfide (DATS) is a lipophilic, H2S‐releasing compound that rapidly degrades under aqueous conditions. Therefore, we sought to prepare a novel solid lipid nanoparticle (SLN) of DATS for ocular delivery.MethodsDATS content was determined by HPLC method using standard solutions (3.12–100 ug/ml). The HPLC parameters consisted of C18 column (Zorbax, 150 mm × 4.6 mm, 5 μm) isocratic elution with methanol and water (85:15). Following method validation, the SLN loaded with DATS were prepared using hot emulsification process, characterized and influence of process parameters on particle size were evaluated.ResultsA well resolved DATS peak was detected at 2.8 mins. The method was validated for linearity (R2 > 0.999); precision (<10%) and accuracy (>90 %). Increasing the concentration of the poloxamer 188 from 0.2% to 1% (w/v) decreased the particle size from 296.7 to 90.46nm. Increasing lipid concentration from 1% to 3% (w/v) increased particle size from 65±5 to 103.4 ± 6 nm. Without the surfactant, glyceryl behenate (GBH) elicited higher particle size (330.8 ± 8.5 nm) than glyceryl monostearate (GMS) (254.4 ± 5.5 nm). Presence of surfactant (poloxamer 1%, soy lecithin 0.2%) reduced particle size to 238.6 ± 8 nm and 85 ± 4.5 nm for GBH and GMS, respectively. Thus, GBH was selected for SLNs and particle size, polydispersity index, zeta potential, and drug loading were 124 ± 2.67 nm, 0.189 ± 0.005, −23.57 ± 3.22mV and 1.5%, respectively. FTIR studies indicated complete encapsulation of DATS.ConclusionAn accurate method for quantification of DATS was developed and validated. A biocompatible system for delivery of DATS was obtained with a particle size less than 200 nm. Studies are in progress to determine release pattern in ocular tissues.Support or Funding InformationCreighton University‐SPAHP, Pharmaceutical Sciences Graduate Program