bluuebunny/crossref_metadata_2025_split huggingface dataset:
Corticosterone at physiological dose accelerates the healing of experimental gastric erosions in rats
Authors: Filaretova Ludmila , Komkova Olga , Morozova Olga 
Published: April 2020

The data of literature about the action of glucocorticoids on the gastric ulcer/erosion healing mainly concern the effects of lasting glucocorticoid therapy or single injection of glucocorticoids at pharmacological doses. These data clearly indicate that glucocorticoids delay the natural healing of experimental gastric injury. However, the role of endogenous glucocorticoids in the gastric mucosal healing processes remained unknown for a long time. In our previous studies we tested this question and the results obtained argue the contribution of endogenous glucocorticoids to the healing of injured gastric mucosa. In the present study we verified whether natural exogenous glucocorticoids (such as corticosterone in rodents) injected at physiological doses similar to endogenous ones may contribute to the healing of gastric erosions accelerating the healing process. For this, in experiments in male SD rats we studied the effects of corticosterone injected at physiological dose 4 mg/kg or dexamethasone injected at the dose 1 mg/kg on the healing of injured gastric mucosa. The glucocorticoid receptor antagonist RU‐38486 (20 mg/kg) was injected to one half of each group 2 h before the glucocorticoid administration. Glucocorticoid or RU‐38486 vehicle (propylene glycol) was injected as a control. Indomethacin (IM) at the dose 35 mg/kg and 3.5 h gastric ischemia‐reperfusion (IR, 30 min occlusion of celiac artery followed by 3 h of reperfusion) were used as ulcerogenic stimuli in preliminary fasted rats. To estimate IM‐ or IR‐induced gastric erosion formation (erosion area) two groups of rats were sacrificed in 4 h after IM injection or 3.5 h after IR. Corticosterone or dexamethasone as well as their vehicle were injected 4 h after IM administration or 3.5 h after IR (0 time point of healing) to other groups to estimate their effects on the healing of injured gastric mucosa in 6 h and 24 h after the hormonal or vehicle administration. IM‐ and IR‐induced erosions healed with time. In control (vehicle treated rats) an average area of erosions in 6 h time point did not differ from that in 0 time point. At the same time an average area of erosions in 24 h time point was significantly lower than that in 0 time point (healing). Corticosterone but not dexamethasone injection accelerated the healing: in corticosterone treated rats significant decrease in an average area of erosions was already observed in 6 h time point. The preliminary glucocorticoid receptor antagonist RU‐38486 injection prevented accelerating effect of corticosterone on the healing process. The findings suggest that natural glucocorticoid corticosterone injected at physiological dose may accelerate the healing of experimental gastric erosions in rats.Support or Funding InformationThe study was supported by grant of Russian Science Foundation (RSF) N 19‐15‐00430.
SPARC: Spinal cord epidural stimulation and microstimulation of dorsal root ganglion with penetrating microelectrode arrays enables selective activation of micturition and continence reflexes.
Authors: Gopinath Chaitanya , Jantz Maria K. , Kumar Ritesh , Nanivadekar Ameya C. , Ogren John I. , Chitnis Girish , Wong Liane , McLaughlin Bryan L. , Fisher Lee E. , Gaunt Robert A. 
Published: April 2020

Lower urinary tract (LUT) dysfunction arising from injury and disease remain a clinical challenge due to unavailability of pharmacological treatments. Neuromodulation devices developed to tackle these disorders, such as sacral stimulators, are non‐selective for a single nerve with numerous off‐target effects while also stimulating the afferent and efferent population in a nerve. Here, we investigate whether epidural spinal cord stimulation (SCS) and microstimulation of dorsal root ganglion (DRG) through penetrating microarrays, can selectively activate and control reflexes relevant to LUT function. We demonstrate that custom high‐density epidural arrays and Utah arrays in the DRG can selectively access pelvic and pudendal innervation, and can modulate LUT function.To determine the effects of stimulation on peripheral nerve recruitment, α‐chloralose anesthetized male cats (SCS: n=6, DRG: n=4) were instrumented with nerve cuffs on the pelvic nerve as well as the pudendal nerve and its branches. High‐density epidural electrodes were placed corresponding to the lumbosacral (L6 and L7 laminae) and sacral (S1 laminae) spinous processes. In separate DRG experiments, 32‐channel high‐density penetrating Utah arrays were implanted in the S1, S2 and S3 DRG. We stimulated epidurally and within the DRG while recording compound action potentials in nerve cuffs. Functional effects of stimulation were measured using intravesical and transurethral catheters to measure bladder and urethral pressures respectively across various stimulus amplitudes and frequencies.All the instrumented nerves could be selectively recruited with both DRG and SCS stimulation, although not every nerve was selectivity recruited in every animal. The stimulation amplitude to evoke functional responses was higher (SCS: 600–1000 μA, DRG: 20–45 μA) than the minimum threshold to evoke antidromic activity in nerve cuffs. SCS and DRG stimulation both evoked bladder parasympathetic contractions similar to direct stimulation of the pelvic nerve. In several trials, stimulation through the same epidural electrode during cystometry, low frequency (3 Hz) stimulation evoked a continence reflex resulting in a suppression of detrusor activity, while high frequency (33 Hz) stimulation evoked a micturition reflex resulting in high intravesical pressures. Isovolumetric and filling cystometry was performed to confirm the action of these reflexes.SCS and DRG stimulation can selectively activate pelvic and pudendal innervation, and elicit micturition and continence reflexes.Support or Funding InformationR01 NS088184 and OT2OD024908. Craig H. Neilsen Foundation Award 476681
Age‐Related Sympathetic Dysregulation is Associated with Glial Senescence in the Brainstem
Authors: Herron Angela , Stansbury Samantha , Balasubramanian Priya , Subramanian Madhan 
Published: April 2020

Aging is an independent risk factor for cardiovascular diseases such as hypertension, myocardial infarction, stroke and heart diseases. Although the specific mechanisms for age‐related increase in the incidence of cardiovascular diseases are not yet known, accumulating evidence suggests that sympathetic nervous system (SNS) dysregulation plays a crucial role. Senescent cells accumulate in the brain with age and are implicated in the pathogenesis of neurodegenerative diseases, possibly through secretion of pro‐inflammatory cytokines, growth factors, and proteases through acquisition of senescence associated secretory phenotype (SASP). Our laboratory studies previously established that aging causes cellular senescence in the key brainstem regions important for sympathetic nervous system activity. In our current study, we investigated which cell type undergoes senescence in the brainstem of aged mice. Neurons are post‐mitotic and do not undergo senescence, whereas glial cells can undergo senescence. Hence, we hypothesized that aging induces glial senescence in the brainstem. To address this hypothesis, we used 28‐month old (n=4) and 4‐month old (n=5) C57BL/6J mice. The animals were sacrificed, and the brainstems were collected. The freshly isolated brainstem was enzymatically digested (45 minutes, 37°C) and filtered through a 30μm mesh to form a cell suspension. Neuron isolation kit from Miltenyi Biotec was used to isolate glial and neuronal enriched cell population from the brainstem cell suspension. RNA was extracted from these sorted cells and used for RT‐PCR analysis. Senescence was assessed using gene expression of cell cycle inhibitors and SASP factors. Data was analyzed by unpaired student’s t‐test and a p‐value less than 0.05 was considered statistically significant. We observed an increase in the gene expression of cell cycle inhibitors, p16, p21 and p53 in the glial cell fraction isolated from the brainstem of aged mice compared to its young counterparts. In addition, there was an increase in the mRNA levels of SASP factors such as the MCP1, TNF‐α, and IL‐1β suggesting that aging induces senescence in the glial cells of the brainstem. We were not able to obtain viable neurons for senescence analysis. Glial cells are known to play a supporting role in neuronal function through regulation of neurotransmission. Future studies will address glial cell specific mechanisms and understand how glia‐neuron crosstalk contributes to SNS dysregulation in aging.Support or Funding InformationNIH‐HL148844 and RED account funds
Optimized Protocol for Robust Differentiation of SH‐SY5Y Cells into Neuronal‐like Cells: An in vitro Model of Human Neuronal Cultures
Authors: Jun Jinwoo , Meyer Madeline R. , Cowles Landry E. , Hall Emma M. , Arnold Benjamin W. , Ambegaokar Surendra S. 
Published: April 2020

The SH‐SY5Y cell line, derived from a human glioblastoma, grow and divide indefinitely under normal conditions, but have the potential to differentiate into neuronal‐like cells when treated with retinoic acid (RA). However, the extent of differentiation has been contested, leading to a variety of protocols to induce differentiation. We took a systematic approach to test the various conditions and treatments used in previously published studies to develop an optimized protocol that yields robust differentiation in an efficient manner. In morphological assays, robust and extensive processes from cell bodies and network development between cells in culture were established when brain‐derived neurotrophic factor (BDNF), B‐27, and potassium (K+) were supplemented to RA, that survived up to 10 days in culture. One‐day treatment of RA and BDNF during differentiation was as effective as prolonged post‐differentiation treatment of BDNF, thus reducing the amount of BDNF required. Conversely, supplements of vitamin B12, AraC, and dB‐cAMP did not provide any significant difference in differentiation. In RT‐qPCR analyses, our optimized protocol led to significant increased expression of microtubule associated protein tau (MAPT) and microtubule associated protein 2 (MAP2), both of which are markers of neuronal cells. We are validating the sub‐cellular localization of these proteins via immunohistochemistry. This optimized protocol thus differentiates SH‐SY5Y cells into robust and reliable neuronal‐like cells, which can be used as a model of human neuronal cells and neurodevelopment in a reproducible in vitro system, without the ethical concerns or practical limitations of using fetal cells for human neuronal cultures.Support or Funding InformationOhio Wesleyan University: Department of Botany and Microbiology, Neuroscience Program, Summer Science Research Program, and Theory‐to‐Practice Grant.
ACTIVATION OF ALC1 (CHD1L) NUCLEOSOME REMODELING BY PARP‐1‐DEPENDENT POLY(ADP‐RIBOSYL)ATION
Authors: Ooi Soon-Keat , Sato Shigeo , Tomomori-Sato Chieri , Conaway Ronald C. , Conaway Joan W. 
Published: April 2020

ALC1, also known as CHD1L, is a macrodomain‐containing SNF2‐family ATPase that has been implicated in various cancers and has apparent roles in DNA repair. ALC1 displays robust ATP‐dependent nucleosome remodeling activity only in the presence of PARP‐1 and NAD+. However, the mechanism by which PARP‐1 stimulates ALC1 nucleosome remodeling activity through NAD+‐dependent poly(ADP‐ribosyl)ation (‘PARylation’) remains less well understood. PARP‐1 is a multi‐domain enzyme that catalyzes most protein PARylation in cells. PARP‐1 consists of an N‐terminal region that includes three zinc finger domains (Zn1, Zn2 and Zn3), a BRCA1 C‐terminal domain (BRCT), a tryptophan‐glycine‐arginine‐rich domain (WGR) and a C‐terminal catalytic domain (CAT) that is responsible for protein PARylation. Previous studies have shown that DNA or nucleosome binding by domains within the PARP‐1 N‐terminal region allosterically activates CAT for poly(ADP‐ribose) (‘PAR’) synthesis.To explore the functions of PARP‐1 domains in stimulating ALC1 nucleosome remodeling activity, we performed a structure‐function analysis of PARP‐1. As expected, the PARP‐1 CAT domain, which is essential for PAR synthesis, is also needed for ALC1‐dependent nucleosome remodeling. To determine whether CAT is sufficient to stimulate nucleosome remodeling by ALC1, we took advantage of a gain‐of‐function mutation in the PARP‐1 CAT domain that renders PARP‐1 PARylation activity independent of DNA binding. CAT with this gain‐of‐function mutation exhibits robust PARylation activity but is unable to activate ALC1 nucleosome remodeling activity, arguing that one or more PARP‐1 N‐terminal domains are needed in addition to CAT for maximal ALC1‐dependent nucleosome remodeling. In further experiments, we tested the abilities of PARP‐1 mutants lacking individual domains within the PARP‐1 N‐terminus to activate ALC1. Consistent with previous studies indicating that the Zn2 and BRCT domains of PARP‐1 are dispensable for protein PARylation, we found that these domains are also dispensable for ALC1 nucleosome remodeling activity. In addition, results of experiments performed with constitutively active PARP‐1 mutants lacking Zn1, Zn3 or WGR domains suggest that each of these domains contribute to ALC1‐dependent nucleosome remodeling. Studies exploring the mechanism(s) by which Zn1, Zn3, and WGR domains contribute to nucleosome remodeling are underway.
SPARC: Different MicroRNA Regulatory Networks Are Active In The Nucleus Of The Solitary Tract During The Development Of Hypertension In Male And Female Spontaneously Hypertensive Rats
Authors: Moss Alison , Kuttippurathu Lakshmi , Achanta Sirisha , Schwaber James S. , Vadigepalli Rajanikanth 
Published: April 2020

Hypertension is a chronic disease affecting millions of people, often leading to heart disease or stroke and is known to affect males and females differently. Previous work in our lab examined the microRNA networks in male Spontaneously Hypertensive Rats (SHRs) in comparison to the wild type Wistar Kyoto (WKY) rats (DeCicco et al., Physiological Genomics 2015). Our results revealed a panel of microRNAs in the nucleus of the solitary tract (NTS) that showed differential expression between the SHR and WKY. Specifically, a subset of microRNAs regulating inflammation and angiotensin pathways were found to have higher expression in the SHR than in the WKY rats at the onset of hypertension. In our present work, we have conducted a similar time series microRNA profiling analysis in female rats allowing us to compare and contrast the results with previously obtained data in males. Rats were sacrificed over the development of hypertension at 8, 12, and 16 weeks of age and brainstems were removed and stored in OCT. Brainstems were sectioned on a cryostat and the NTS was extracted using a micropunch. As previously reported in DeCicco et al. (2015), total RNA was extracted and samples were analyzed for expression of over 400 miRNAs using the Nanostring nCounter system. Our analysis revealed extensive differences in the differential expression of miRNAs in males vs. females. Consistent across both sexes is the finding that miRNA levels in SHR and WKY differ primarily at the onset of hypertension. However, differential regulation in SHR vs. WKY was opposite in direction between males and females. Male SHR showed upregulation of a subset of miRNAs at the onset of hypertension, which were not statistically significant in the female SHR vs. WKY at the same stage. By contrast, female SHR showed downregulation of a distinct set of miRNAs that were not differentially regulated in the male SHR vs. WKY, at the onset of hypertension. These results suggest that miRNA regulatory networks operate in a sex‐specific manner during the development of hypertension. Examination of these regulatory networks lends important insight into the different autonomic control mechanisms driving hypertension in males and females.Support or Funding InformationSupported by the NIH Common Fund SPARC Program award OT2 OD023848 and NIH NHLBI Multiscale Modeling award U01 HL133360.
Aerobic Exercise Training Prevents Obesity and Insulin Resistance Independent of Changes in the Skeletal Muscle ACE2/Ang 1‐7/Mas Axis.
Authors: Evangelista Fabiana S. , Vecchiatto Bruno , Américo Anna Laura V. , Martucci Luiz Felipe , Ferreira Marilia M. , Muller Cynthia R. 
Published: April 2020

Aerobic exercise training (AET) has been widely used for the prevention and treatment of obesity and insulin resistance (IR). Improvements in the oxidative capacity of skeletal muscle can mediate the protective effect of AET. Considering the role of angiotensin converting enzyme 2 (ACE2)/angiotensin 1‐7 (Ang 1‐7)/receptor Mas axis activation in reducing cardiometabolic diseases, the present study aimed to evaluate if the prevention of obesity and IR through AET is associated with changes in the ACE2/Ang (1‐7)/Mas axis in the skeletal muscle. Adult male C57BL6/J mice were assigned into groups (n=10/group): chow‐fed controls (C), chow‐fed trained (T), cafeteria diet (CAF), and cafeteria diet and trained (CAFT). AET was performed simultaneously with diet and consisted of 8‐wk running session of 60 min at 60% of maximal speed, 5 days/wk. Experimental procedures were approved by Ethics Committee from School of Arts, Science and Humanities, University of Sao Paulo, Brazil (#001/2016). The CAF group presented higher body weight gain and adiposity, glucose intolerance, IR and increased lipid deposition in the liver while AET prevented such damages in the CAFT group. Food consumption did not change among the groups. During the maximal physical exertion test, the T group increased VO2máx and both T and CAFT groups showed higher maximal speed, higher speed on the VO2máx and lower relative running cost compared to C and CAF groups. The enzymatic activity of citrate synthase and β‐hydroxyacyl‐CoA dehydrogenase (β‐HAD) in the soleus muscle increased in the T (352 ± 21.5 mmol/min/mg and 80.1 ± 6.6 mmol/min/mg) and CAFT (350 ± 22.4 mmol/min/mg and 87.9 ± 7.3 mmol/min/mg) groups compared to C (272.7 ± 9.5 mmol/min/mg and 62.7 ± 3.9 mmol/min/mg) and CAF (254.6 ± 15.7 mmol/min/mg and 46.7 ± 1.6 mmol/min/mg) groups. Protein expression of mitofusin 1, mitofusin 2 and dynamin related protein 1 (Drp1) did not change among groups. Also, no differences were observed in the ACE2 and Ang (1‐7) levels nor in the receptor Mas protein expression. In conclusion, the AET prevented the increase in body weight, adiposity and IR induced by cafeteria diet, improved the aerobic capacity and promoted the increase in oxidative enzymes activity in the soleus muscle. However, the adaptations induced by AET were not associated with changes in the ACE2/Ang (1‐7)/Mas axis in the skeletal muscle.Support or Funding InformationSão Paulo Research Foundation (FAPESP #2015/04948‐4; #2016/23783‐9; #2016/20659‐5).
Calcium Chloride Enhance Crystal Growth of an Uncharacterized GNAT Enzyme
Authors: Robles Alyssa , Arada Angelika , Baumgartner Jackson , Houseman Charles , Variot Cillian , Kuhn Misty L. 
Published: April 2020

Gcn5‐related N‐acetyltransferases (GNAT) are widespread across all domains of life and are capable of acetylating an assortment of substrates. However, many of their structures and functions remain unknown in bacteria. Our laboratory currently studies uncharacterized GNATs from Pseudomonas aeruginosa. We previously found the enzyme PA3944 acetylated polymyxin antibiotics and observed there was a duplicate GNAT gene (PA3945) with approximately 75% identity on the same operon. This protein has not been structurally or functionally characterized. Therefore, we screened this enzyme for activity using a broad‐substrate screening assay and set up crystallization screens to obtain protein crystals. Unfortunately, the PA3945 enzyme did not acetylate any substrates in the kinetic screening assay, which indicates it has a separate role compared to the PA3944 enzyme. We identified crystallization conditions that yielded microcrystals in the presence of calcium chloride. We further optimized these conditions using calcium chloride as an additive, which yielded larger crystals. Currently, we are investigating whether calcium chloride plays a role in enzyme activity and whether we can further optimize the crystallization conditions to yield suitable crystals for X‐ray diffraction and structure elucidation.Support or Funding InformationResearch reported in this work was supported by the National Science Foundation under Grant Number CHE‐1708863 (to MLK).
Connexin43 as a Therapeutic To Restore Cardiac Structure in Arrhythmogenic Heart Disease
Authors: Zhang Jing , Zanella Fabian , Lyon Robert , Mezzano Valeria , Roberts Jason , Ursell Philip , Carromeu Cassiano , Gu Yusu , Martin Jody , Muotri Alysson R. , Scheinman Melvin , Peterson Kirk L. , Sheikh Farah 
Published: April 2020

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is termed a fatal “disease of the desmosome” as 40–50% of patients harbor mutations in genes associated with the desmosome, a mechanical based cell‐cell junction structure found between cardiac muscle cells. Connexin43, the most dominant gap junction protein in ventricles, has been classically associated with electrical functions between adjacent cardiac cells, is consistently downregulated and considered an early disease hallmark of ARVD/C. However, limited efforts have focused on dissecting the role of connexin43 in ARVD/C, especially during end‐stage cardiac disease, where structural alterations are integral in facilitating ventricular failure, arrhythmias and premature death. Here we show that genetic restoration of connexin43 in human and mouse models of ARVD/C is sufficient to bypass desmosomal structural deficits as well as circumvent disease and premature death. In vitro studies demonstrated the ability of human induced pluripotent stem cell (hiPSC)‐derived cardiomyocytes to recapitulate classic variations in desmosomal structural defects and reveal connexin43 loss as a molecular predictor of physiological severity within ARVD/C hearts in a donor‐specific manner. Adenoviral restoration of connexin43 could rescue baseline and catecholamine induced electrical and contractile physiological deficits in ARVC hiPSC derived cardiomyocytes in absence or presence of desmosomal structural alterations. Furthermore, in vivo cardiac‐specific connexin43 gene therapy could prolong lifespan and restore cardiac structure (desmosomal protein expression) in a mouse model with end‐stage ARVC, in a dose‐dependent manner. Our results provide evidence for non‐canonical and independent functions for connexin43 in mechanical modulation of junctions. We anticipate that our findings will have broad implications in exploiting connexin43 as a viable therapeutic target in advanced diseases associated with underlying structural defects.Support or Funding InformationDepartment of Defense (PR170125); National Institutes of Health (NIH R01 HL142251‐A1); American Heart Association Postdoctoral Fellowship (18POST34060228)