bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased basal and adenosine‐mediated coronary flow in ex vivo hearts from type I diabetic mice (1051.16)
Authors: Labazi Hicham , Zhou Xueping , Teng Bunyen , Mustafa S. Jamal 
Published: June 2021

Diabetes is known to cause morphological and functional changes in the cardiovascular system, resulting in abnormal responses to various stimuli such as adenosine. Our aim was to examine the functional changes in coronary flow (CF) to adenosine receptor (AR) agonists resulting from type I diabetes. Diabetes was induced in mice using streptozotocin (STZ, 10mg/Kg; 8 weeks) and concentration response curves to the non‐selective AR agonist NECA and to the A2A AR selective agonist (CGS‐21680; CGS) were performed in isolated perfused hearts from STZ and vehicle (C) group. Diabetes resulted in a decrease in heart weight (0.093g ± 0.002 in STZ vs. 0.117g ± 0.004 in C; p<0.05), an increase in blood glucose level (510.8mg/dL ± 22.2 in STZ vs. 140.9mg/dL ± 9.4 in C; p<0.05) and an increase in the basal coronary flow (21.6 ± 1.5 in STZ vs. 16.1 ± 0.6 in C; p<0.05). Both NECA and CGS induced a concentration‐dependent increase in CF (ml.min‐1.mg‐1) which was significantly increased in STZ compared to C (NECA: Emax 39.8 ± 1.8 in STZ vs. 28.2 ± 0.7 in C; p<0.05) (CGS; Emax 38.8 ± 1 in STZ vs. 28.3 ± 1.8 in C; p<0.05). No significant differences were observed between the groups for changes in both heart rate and left ventricular diastolic pressure to both agonists. Our data suggest that STZ‐induced diabetes resulted in an increase in basal CF as well as increased vasodilatory response to adenosine agonists, probably by upregulating A2A receptor signaling.Grant Funding Source: Supported by HL 094447 and HL 027339
Protein and gene expression of angiotensin II receptors (AT1 and AT2) in aorta of diabetic and hypertensive rats (1051.6)
Authors: Romero Rodrigo , Reséndiz‐Albor Aldo , Rodriguez Jessica , Sanchez‐Muñoz Fausto , Hong Enrique , Villafaña Santiago 
Published: June 2021

Diabetes and hypertension have been associated with cardiovascular disease and stroke. Some reports have been related the coexistence of hypertension and diabetes with increases in the risk of developing vascular complications. Recently some studies have shown contradictory results suggesting that in early stages of diabetes and hypertension exist a reduced functional response to vasoconstrictor agents like angiotensin II (Ang II) which plays an important role in blood pressure regulation mechanism through the activation of its AT1 and AT2 receptors. For that reason, the aim of this work was to study the gene and protein expression of receptors AT1 and AT2 in aorta of diabetic SHR and WKY rats. Diabetes was induced by the administration of streptozotocin (60 mg/kg i.p.). After 4 weeks of the onset of diabetes the protein expression was obtained by western blot and the mRNA expression by RT‐PCR. Our results showed that the hypertensive rats have a higher mRNA and protein expression of AT1receptors than normotensive rats while the AT2 expression was unchanged. On the other hand, the combination of diabetes and hypertension increased the mRNA and protein expression of AT1 and AT2 receptors significantly. In conclusion our results suggest that diabetes with hypertension modifies the mRNA and protein expression of AT2 receptors and these changes could be associated with the reduction in the response to Ang II in early stage of diabetes.Grant Funding Source: CONACYT CB‐2012‐01‐183660/COFAA
Expression of the orphan receptors GPR22, GPR162, GPR27 and GPR17 in cardiovascular tissues of diabetic rats (1051.7)
Authors: Ruiz H Armando , Hong Enrique , Sanchez‐Muñoz Fausto , Villafaña Santiago 
Published: June 2021

Diabetes mellitus is a chronic degenerative disease characterized by high blood glucose levels as a result of problems in the action or secretion of insulin. Although there exist treatments for this pathology, it has been associated with a high mortality. For this reason, it is important to try to identify new pathways that could be involved in the diabetes. Recently, a new class of receptors has been reported, called orphan receptors because the associated ligand and signaling pathways are unknown, these receptors have been associated with certain pathologies. Therefore, the aim of this work was to study the expression of the orphan receptor GPR22, GPR162, GPR27 and GPR17 in heart, aorta, brain and kidney of diabetic rats. We used male rats of Wistar strain with 10‐12 weeks of age. Diabetes was induced by a single dose of streptozotocin (60 mg/kg i.p.). After 4 weeks, the tissue was obtained and the expression of the mRNA was measured by RT‐PCR. Our results showed that the orphan receptors are expressed in a different way in heart, kidney, brain and aorta of diabetic and non‐diabetic rats. In conclusion, we suggest that orphan receptors could be involved in the development of diabetes.Grant Funding Source: CONACYT CB‐2012‐01‐183660/COFAA
A corneal penetrating drug delivery system based on elastin‐like polypeptide (1053.4)
Authors: Bidwell Gene , Liu Huiling , Robinson Grant , Marquart Mary , George Eric 
Published: June 2021

The corneal epithelium is connected by tight junctions and serves as a protective layer, but its resistance to penetration also presents a challenge to drug delivery. Upon injury, the cornea is susceptible to infection and/or neovascularization (NV), both of which can threaten sight. In the case of corneal bacterial infection, delivery of antibiotics and the development of antibiotic resistance are significant hurdles to effective therapy. In the case of corneal NV, there are no good treatments beyond removal of the insulting agent and resting of the eye. The goal of this study was to generate an effective and non‐toxic protein‐based delivery system for targeting therapeutic agents through the corneal epithelium. This drug delivery system utilized a biopolymer called elastin‐like polypeptide (ELP), an engineered protein that is easily purified and easily modified to carry drugs or therapeutic proteins. To facilitate delivery to the corneal stroma, we fused cell penetrating peptides (CPPs) to ELP. Addition of CPPs enhanced the total uptake and retention of ELP as much as 3‐fold in healthy rabbit corneas and in a rabbit burn model of corneal NV. The CPP also mediated penetration of ELP beyond the epithelium and basal lamina into the stromal layer. Our results demonstrate that CPP‐ELPs are a powerful platform for corneal drug delivery, and we describe their use for delivery of antibacterial and antiangiogenic agents.Grant Funding Source: Supported by an Intramural grant to GLB from U of MS Med Center and NIH grant 1K99HL116774‐01 to EMG
Evaluation of functional activity and aggregation properties of hemopressin (1054.2)
Authors: Nayak Surendra , Song Benben , Kibler Patrick , Adem Amina , Endsley Aaron , Jambunathan Kalyani , Galande Amit 
Published: June 2021

Hemopressin is a naturally occurring nonapeptide derived from the α‐chain of hemoglobin that acts as an inverse agonist for the type‐1 cannabinoid (CB1) receptor. Based on its in vivo activity, hemopressin is considered to have potential therapeutic applications in hypertension, pain, and obesity. We tested the hemopressin peptide for CB1 receptor agonist and antagonist activity in cAMP and β‐arrestin recruitment assay and found it to be inactive. The lack of reproducibility of CB1 receptor antagonist/ inverse agonist activity of hemopressin has been attributed to formation of aggregates. Hemopressin was previously reported to convert into amyloid‐like fibrils under aqueous conditions. However, the amino acid residues that modulate the aggregation propensity of hemopressin are not known. We have synthesized 25 different analogs of hemopressin and analyzed their aggregation properties using the principle of dynamic light scattering. We identified four conservative changes in the peptide sequence (Val2→DVal2, Asn3→Gln3, Leu7→Npg7, and C‐OH→C‐NH2) that lower the aggregation propensity of hemopressin. The results indicate that hemopressin aggregation is cooperative in nature and involves contribution from multiple amino acids within the peptide chain. The analogs are being evaluated for their functional activity in CB1 receptor assays. The structure‐function studies of hemopressin would further help understand its aggregation property and explore its potential therapeutic applications.Grant Funding Source: Supported by the National Institute on Drug Abuse of the NIH under Award Number R21 DA034422.
The impact of immune modulators from the group of substituted thiadiazines on the severity of stress reaction (1054.7)
Authors: Sarapultsev Alexey , Chupakhin Oleg , Sarapultsev Petr , Mukhlynina Elena , Sarapultsev German , Medvedeva Svetlana , Danilova Irina 
Published: June 2021

Central mode stress relieving effect of immune modulators from the group of substituted thiadiazines.Stress reaction is characterized by a number of changes on the part of immune system in the form of high concentration of neutrophils, decreasing aggregate amount of lymphocytes, as well as appearance of catecholamine block of pancreas α‐receptors, which at the early stages of stress causes the so‐called «strain diabetes», and at its final stage (stage of exhaustion), progress of typical «steroid diabetes».Previous studies demonstrated that the main effect mechanism of compounds from the group of substituted thiadiazines is their capability to modulate inflammation process. The goal of the present research was the evaluation of their effect on the course of stress reaction. The experiment was conducted by the pattern of 6‐hour and 48‐hour immobilization stress with rats. The animals got injection of the compounds, dozed 40 mg/kg. Histological study and biochemical analysis has been carried out at the 6 and 48 hours of the experiment.On the background of compounds introduction, we detected lowering level of corticosterone, changes in the histomorphology of lymphopoiesis organs, as well as increase in the number of lymphocyte and monocyte series in the setting of decreasing number of eosinophils in the blood. The conducted research allowed to assume the existence of central effect mechanism of immune modulators from the group of substituted thiadiazines.Grant Funding Source: Supported by grant 12‐M‐34‐2064
Fyn kinase regulates microglial neuroinflammatory responses in cell culture and animal models of Parkinson’s disease (1055.7)
Authors: Panicker Nikhil , Jin Huajun , Saminathan Hariharan , Kanthasamy Kavin , Anantram Vellareddy , Kanthasamy Anumantha , Kanthasamy Arthi 
Published: June 2021

Sustained neuroinflammation is recognized as a key pathophysiological contributor to many neurodegenerative diseases, including Parkinson’s disease (PD). Resident brain microglia mediate chronic neuroinflammation through the production of proinflammatory cytokines and chemokines. Identifying the key molecular signaling events perpetuating microglial activation could unravel novel mechanisms underlying glial‐neuronal interactions that contribute to persistent inflammation and progressive neurodegeneration in PD. In the present study, we examined the role that Fyn, a non‐receptor tyrosine kinase, plays in microglial activation in cell culture and animal models of PD. First, we show that the known inflammogen LPS (lipopolysaccharide) rapidly activated Fyn kinase, as measured by Fyn‐Y416 phosphorylation and Fyn kinase assays in the BV2 microglial cell line as well as in primary microglia. Notably, immunocytochemical studies revealed that activated Fyn is preferentially localized to the microglial membrane periphery. Furthermore, stimulation of microglia with LPS induced phosphorylation of PKCδ at tyrosine 311. PKCδ Y311 phosphorylation was diminished in Fyn Knockout (Fyn KO) microglia, indicating that Fyn mediates this event. Functional studies revealed that the LPS‐induced production of cytokines, chemokines and nitrite were significantly attenuated in microglia isolated from Fyn KO and PKCδ KO primary microglia, when compared to wild type microglia. Furthermore, Fyn was found to be essential for LPS‐induced MAP kinase phosphorylation and activation of the NFκB pathway. Next, we extended our studies to LPS and MPTP‐induced animal models of neuroinflammation. We observed attenuated microglial proliferation and reduced production of the striatal TNFα, IL‐6 and IL‐12 in Fyn knockout mice. Collectively, these findings suggest that Fyn‐PKCδ signaling plays a critical role in mediating neuroinflammatory responses in PDGrant Funding Source: Supported by NIH grants NS65167 and NS078247
Evaluation of anti‐inflammatory effect of analogs of L‐carnitine in a model of chronic inflammation in vivo (1056.1)
Authors: Mendoza‐Rivera Brissa , Reyes‐Esparza Jorge , De La Cruz Cordero Ricardo , Rodriguez‐Fragoso Lourdes 
Published: June 2021

In this project we developed a model of chronic inflammation induced by subcutaneous implantation of cotton tassel to induce granuloma formation and evaluate drug efficacy of 3 analogs of L‐carnitine. Chronic granulomatous inflammation is a specific type of chronic inflammatory reaction, characterized by the accumulation of modified macrophages (epitheloid cells). Wistar male rats with granuloma were treated with the three analogs at a dose of 2mg/kg. Different serum interleukins were determined and histological analysis of thymus, spleen and granuloma was made. The analysis shows a reduced level of pro‐inflammatory interleukins (Il‐6 and TNF‐α) in animals treated with analogs having a greater effect the analog 2 and 3. Histological analysis showed the presence of epithelioid cells and giant cells in animals treated with L‐carnitine and analog 1, whereas animals treated with analogue 2 and 3 showed leukocyte infiltration. With regard the thymus, only was seen an increase in medulla area with the analog 2. While in the spleen was observed a reduction of medulla area with the analogs 2 and 3. In conclusion the analogs had anti‐inflammatory and anti‐granuloma activity, but they had different efficacy.Grant Funding Source: CONACYT
Arachidonic acid induced calcium signaling at acidic pH (1057.2)
Authors: Moss Nicholas , Hou Bing , Young Richard , Bruns Alexander , Wilson Lesley , Beech David 
Published: June 2021

Arachidonic acid (AA) induces calcium signalling and downstream functional responses. It is often present in pathophysiological environments where there is also acidity, as in ischaemic tissues and tumours. The aim of our study was to investigate the relevance of the acidic environment to AA‐evoked responses. In intracellular Ca2+ measurement experiments, AA induced a small Ca2+ influx at pH 7.4 in human umbilical vein endothelial cells which was potentiated by almost an order of magnitude at pH 6.8. The response at pH 6.8 was not dependent on the AA‐activated channels TRPV4 or Orai3. Unexpectedly, inhibitor antibodies targeted to TRPC4 or TRPC5 suppressed the response. Furthermore, TRPC5 channels stably expressed in HEK293 cells were activated by AA at pH 6.8 but not 7.4. The data suggest that mild acidosis strongly potentiates the contribution of TRPC channels to AA responses.Grant Funding Source: Supported by the British Heart Foundation
Mechanisms underlying behavioral tolerance following repeated 5‐HT2CR agonist administration in vivo (1059.11)
Authors: Cooper Debra , Davis‐Reyes Brionna , Bubar Marcy , Cunningham Kathryn 
Published: June 2021

The serotonin 5‐HT2C receptor (5‐HT2CR) is known to play a role in several psychiatric disorders. Repeated treatment with 5‐HT2CR agonists, however, may induce tolerance to the therapeutic effects by altering receptor responsiveness. The present study explores the molecular mechanisms underlying tolerance to 5‐HT2CR agonist‐induced hypomotility following repeated administration. Male, Sprague‐Dawley rats were treated daily for seven days with saline or the preferential 5‐HT2CR agonist MK 212 (2 mg/kg, IP, BID). Administration of MK 212 (2mg/kg, IP) 24‐hrs following the 7‐day regimen induced hypomotility in saline treated rats, which was blunted following repeated MK 212 treatment, suggesting tolerance developed to the 5‐HT2CR agonist. This loss of 5‐HT2CR responsiveness was not associated with changes in crude membrane‐bound 5‐HT2CR protein expression in the ventral tegmental area, nucleus accumbens or prefrontal cortex. More detailed assessments of 5‐HT2CR expression, subcellular localization and trafficking are being explored in a separate group of rats treated daily for seven days with the more selective 5‐HT2CR agonist lorcaserin (Belviq®), the first‐in‐class selective 5‐HT2CR agonist approved by the FDA for obesity. Mechanisms identified in this study will be important in addressing tolerance to the therapeutic effects of 5‐HT2CR agonists in clinical use.Grant Funding Source: Supported by: DA033935, DA020087, DA07287, DA13595, DA15259, GM069285
Development of novel serotonin 7‐targeting compounds based on the 2‐dimethylaminotetralin scaffold (1059.13)
Authors: Canal Clinton , Felsing Daniel , Zhu Wanying , Liu Yue , Cordova‐Sintjago Tania , Booth Raymond 
Published: June 2021

The serotonin (5‐HT) 7 G protein‐coupled receptor (GPCR) is the most recent 5‐HT receptor cloned, and is expressed in both the periphery and the CNS. Reports propose 5‐HT7 receptors are involved in a wide range of CNS functions, including modulation of circadian rhythms, sleep, pain, body temperature, and cognition. 5‐HT7 receptors couple to Gαs, leading to activation of adenylyl cyclases and production of cAMP. Due to paucity of available, selective 5‐HT7 ligands, the complexity of CNS processes and to a limited number of studies examining 5‐HT7, however, there is no consensus about 5‐HT7 receptor CNS neuropharmacological function. We have begun an iterative 5‐HT7 receptor structure‐based ligand synthesis program to develop novel 5‐HT7‐targeting phenylaminotetralin (PAT) compounds. A molecular model of the 5‐HT7 receptor was built by homology to the recently reported structure of the 5‐HT1B GPCR, and computational ligand docking studies were undertaken. Computational results were validated by experimental results of ligand affinity (Ki) at agonist‐labeled human 5‐HT7 receptors in membranes prepared from HEK cells stably expressing a high density of receptors (~7 pmol/mg protein). A number of PAT ligands had Ki 蠄 7 nM at 5‐HT7 receptors. PAT ligands with Ki less than 50 nM at 5‐HT7 receptors were assessed for 5‐HT7 receptor‐mediated cAMP formation in the 5‐HT7 stable cells; the PATs assessed behaved as inverse agonists or partial agonists with IC/EC50 values similar to their Ki values. PAT affinities were also determined at human 5‐HT2A, 2B, and 2C, histamine H1, α1A, 1B, 2A, 2B, and 2C adrenergic GPCRs. In translational studies, none of the PAT compounds tested were active in the hot‐plate analgesia assay in C57Bl/6J mice after peripheral administration, including PATs known to cross the blood‐brain barrier. Additional medicinal chemical syntheses, guided by results from molecular modeling and ligand docking studies are underway, as are in vitro and in vivo neuropharmacology studies.Grant Funding Source: Supported by NIH R01 DA030989 and MH081193
A translational approach to nicotine dependence: interrogating the Neuregulin‐ErbB4 pathway in mouse and man (1059.6)
Authors: Turner Jill 
Published: June 2021

Addiction to nicotine and ability to quit smoking are influenced by genetic factors. Recently, we published data using functional genomic approaches (chromatin immunoprecipitation and whole genome sequencing) to identify novel CREB targets following chronic nicotine administration and withdrawal (Mol Psychiatry 2013). We observed in rodents that nicotine withdrawal modulates CREB binding to the gene for Neuregulin 3 (NRG3). Further studies in humans indicated that SNPs across NRG3 were significantly associated with prospective smoking cessation. NRG3 is a neural‐enriched member of the EGF family, and a specific ligand for the receptor tyrosine kinase ErbB4, which is also up‐regulated following nicotine treatment and withdrawal. Our findings, along with a recent study identifying associations of ErbB4 with smoking status (Loukola 2013), strongly implicate this pathway in the molecular mechanisms underlying nicotine dependence and smoking cessation. Interestingly, in addition to its relevance in smoking cessation, this pathway has also been described in the pathophysiology of schizophrenia, suggesting a common molecular link between these two highly co‐morbid diseases. Ongoing experiments examining molecular changes downstream of NRG3/ErbB4 signaling indicate that alterations in NMDAR signaling may be influencing both smoking behavior as well as schizophrenia.Grant Funding Source: Supported by 1‐K99‐DA032681‐01 and1‐R00‐DA032681‐02.
Hyperbaric oxygen suppresses paclitaxel‐induced cold allodynia in rats (1061.2)
Authors: Zhang Yangmiao , Nelson Jordan , Shirachi Donald , Quock Raymond 
Published: June 2021

HBO2 treatment can relieve chronic pain (Thompson et al., Neurosci Res 66:279, 2010). Previously, we reported that HBO2 suppressed PAC‐induced mechanical allodynia (Zhang et al., FASEB J 26:662.9, 2012). The aim of this study was to determine whether HBO2 treatment could also reduce PAC‐induced cold allodynia. Male Sprague Dawley rats, 250‐350 g, were injected intraperitoneally with either 1.0 mg/kg PAC or vehicle on days 0, 2, 4 and 6. On day 7, rats were treated with 60‐min HBO2 at 3.5 atmospheres absolute (ATA) or room air for either one or four days. Cold allodynia was assessed every other day by applying 50 µL acetone to each hind paw. Allodynia was scored using a 0‐3 point scale. Results showed that PAC‐treated rats developed cold allodynia in response to acetone. A single 60‐min HBO2 treatment at 3.5 ATA did not produce obvious recovery from allodynia. However, allodynia was suppressed in rats that underwent four daily 60‐min HBO2 treatments. These results indicate that, while one HBO2 treatment is not sufficient to reduce PAC‐induced cold allodynia, repeated (4×) HBO2 treatment can suppress the development of PAC‐induced cold allodynia.Grant Funding Source: Supported by NIH Grant AT‐007222 and the Allen I. White Distinguished Professorship.
A novel class of allosteric ligands modulating TRPA1: discovery of a switch in agonist‐antagonist function (1061.7)
Authors: Herz Jeffery , Zhu Yingmin , Lu Yungang , Kesicki Edward , Thomsen William , Zhu Michael 
Published: June 2021

TRPA1 functions as a ligand‐gated cation channel in sensory neurons and is an important drug discovery target for identification of novel analgesics. We report identification of a novel structural class of ligands reversibly modulating TRPA1 channel function. Using intracellular calcium measurement and whole cell patch clamp recording of HEK293 cells expressing human TRPA1, we characterized the structure‐activity relationships among a group of amino‐triarylmethane analogs. A minimal structural change switched a full agonist to antagonist and small changes in side chain substituents in the same ring greatly altered affinity among antagonists. The agonists, ALGX‐2014 and ALGX‐2015, only elicited TRPA1 currents when applied extracellularly. Their stimulatory effect was blocked by TRPA1 antagonists and unaffected by substituting the three cysteine residues of TRPA1 critical for covalent stimulation by electrophilic agonists, such as AITC and PGJ2, with alanines, suggesting channel activation occurs in a noncovalent manner. This novel class of allosteric agonists and antagonist ligands also interact with other well‐defined TRPA1 ligands and results suggest a highly conserved binding site among TRPA1 and other members of the thermo‐TRP family which may reside in the channel domain.Grant Funding Source: Supported by NIDA grant (DA031516) to JMH and NIDDK grant (DK081654) to MXZ