bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of HRas signaling by Rabex‐5‐mediated ubiquitination
Authors: Xu Lizhong , Lubkov Veronica , Taylor Laura , Bar‐Sagi Dafna 
Published: June 2021

Mammalian cells express three isoforms of Ras proteins, HRas, NRas and KRas4B (referred to as KRas hereafter). Each isoform plays an important role in controlling a wide spectrum of fundamental cellular processes. We have recently shown that the location‐specific signaling activity of HRas and NRas but not KRas is regulated by ubiquitination. The objective of this study is to identify the molecular mechanism by which Ras ubiquitination is regulated. Using the in vivo and in vitro ubiquitination assays along with RNA interference technology, we have found that the E3 ligase Rabex‐5 (also known as RabGEF1), but not its ligase‐deficient counterpart (Y25A/Y26A), is necessary and sufficient to catalyze Ras ubiquitination. Rabex‐5‐mediated HRas ubiquitination promotes its endosomal localization and leads to the suppression of ERK activation. Furthermore, the Ras effector RIN1 enhances HRas ubiquitination through its Rab5 GEF activity in a Rabex‐5 dependent manner. Thus RIN1 and Rabex‐5‐dependent Ras ubiquitination represents a new modality for the regulation of Ras compartmentalization and signaling.This work was supported by research grants from National Institutes of Health to D.B.‐S. (CA55360 and GM078266).
Glutamatergic Receptor Activation in the Rostral Ventrolateral Medulla Contributes to the Sympathoexcitatory Response of Hyperinsulinemia
Authors: Bardgett Megan Elyse , Stocker Sean D 
Published: June 2021

Hyperinsulinemia increases sympathetic nerve activity (SNA) and has been linked to cardiovascular morbidity in obesity. Many sympathoexcitatory responses are mediated by glutamatergic receptor activation of spinally projecting neurons in the RVLM. Therefore, we hypothesized that ionotropic glutamate receptors in the RVLM contribute to elevated SNA during hyperinsulinemia. Hyperinsulinemic‐euglycemic clamps were performed in urethane‐anesthetized, male Sprague‐Dawley rats (270‐350g, n=8) by IV infusion of insulin (7.5 mU/kg/min) and 50% dextrose (.25‐.75 ml/hr) for 120 min. After 90 min, hyperinsulinemic clamps significantly increased plasma insulin (2.5±0.9 to 12.2±3.9 ng/ml, P<0.05), elevated lumbar (125±18%, P<0.01) and renal SNA (48±17%, P<0.05) without any significant change in arterial blood pressure (0 min: 125±3 vs 90 min: 118±4 mmHg) or plasma glucose levels (0 min: 107±9 vs 90 min: 111±10 mg/dl). RVLM injection of the glutamate receptor antagonist kynurenic acid (5 nmol/60 nL/ side, n=4) vs saline (n=4) significantly reduced lumbar SNA (‐41±1% vs 3±1%, P<0.01) but did not significantly alter renal SNA (27±14% vs 0±3%) or arterial blood pressure (1±2 vs ‐1±1 mmHg). These findings indicate that hyperinsulinemia increases lumbar SNA, in part, through glutamatergic receptor activation in the RVLM.Supported by NIH HL090826, AHA 0630202N & 0815372D
Survivin is a key factor in the differential susceptibility of gastric endothelial and epithelial cells to alcohol‐induced injury
Authors: Jones Michael K. , Padilla Oscar R. , Zhu Ercheng , Ngov Melisa 
Published: June 2021

We previously demonstrated that the anti‐apoptosis protein, survivin, plays a protective role against alcohol‐induced gastric injury. Since the endothelia is a primary target of alcohol‐induced gastric damage, we investigated whether survivin expression is a key factor in the greater susceptibility of gastric endothelial vs. epithelial cells to alcohol‐induced injury. Here, we demonstrate that rat gastric epithelial cells expressed 8‐fold (P<0.01) greater survivin levels vs. rat gastric endothelial cells. Survivin expression correlated (r=0.84, P<0.05) with resistance of gastric epithelial vs. endothelial cells to both alcohol‐induced cell damage (20 ± 3% vs. 65 ± 7%, P<0.05) and alcohol‐induced apoptosis (14 ± 2% vs. 32 ± 4%, P<0.05). Forced overexpression of survivin in gastric endothelial cells significantly increased resistance to both alcohol‐induced damage and apoptosis. Moreover, overexpression of a threonine‐34 to glutamate mutant survivin construct rendered gastric endothelial cells significantly more resistant to alcohol‐induced damage and apoptosis vs. non‐transfected gastric epithelial cells (P<0.05). These findings indicate that disparate survivin expression levels can explain the discrepancy between gastric epithelial and endothelial cell susceptibility to alcohol‐induced injury; and, survivin phosphorylation is important in mediating gastric mucosal protection.NIH R01AA14946
Estrogen Receptor β in Female Adipose Tissue: Impact on Metabolic Dysregulation in a Model of Senescence and Estrogen Deficiency
Authors: Tomicek Nanette J. , Lancaster Timothy S. , Korzick Donna H. 
Published: June 2021

BackgroundObesity and associated metabolic risk are increased following menopause and may be associated with disturbances in estrogen receptor (ER) signaling in adipose depots. However, the role of ER subtypes on increasing adiposity with aging remains uninvestigated.PurposeTo determine the singular and combined effects of aging and estrogen deficiency on ER levels and to identify dysregulated downstream signaling in adipose tissue of female rats.MethodsVisceral adipose tissue was isolated from adult and aged female F344 rats (n = 5‐6/group) with ovaries intact or removed (OVX). Protein levels were assessed with western blotting and circulating estradiol through radioimmunoassay.ResultsRat weight increased significantly with both age and OVX and was greatest in aged OVX. ER β levels increased two‐fold in both aged and aged OVX, while ERα decreased in adult OVX only. PPARγ2 levels were also reduced in aged OVX, in conjunction with a non‐significant increase in adiponectin receptor 1 levels (p = 0.098).SummaryThese data suggest, for the first time, that alterations in adipose ERβ levels may contribute to obesity and altered metabolic risk with age‐associated estrogen deficiency. ERβ‐mediated suppression of PPARγ2 may also represent a potential downstream signaling mechanism to exacerbate metabolic risk with post‐menopausal estrogen deficiency via alterations in adiponectin signaling.
HMGB1/TLR4 axis contributes to A/R‐induced cardiomyocyte apoptosis through potentiating TNFα/JNK pathway
Authors: Xu Xuemei , Yao Yongwei , Kao Raymond , Martin Claudio M , Rui Tao 
Published: June 2021

The present study is to explore the role of HMGB1/TLR4 axis in the myocyte apoptosis‐induced by A/R (an in vitro counterpart to I/R).Methodscardiomyocytes derived from wild type or TLR4 deficient mice were challenged with an A/R. HMGB1, TNFα expression (Western blot and ELISA), myocyte apoptosis (caspase 3 activity and cell death ELISA) and JNK and NFκB activation (p65 phosphorylation) (Western blot) assessed.ResultsA/R challenge to myocytes resulted in an increase in HMGB1 expression and extracellular release. Inhibition of HMGB1 attenuated the apoptosis and A/R‐induced TNFα production. Treatment of cardiomyocytes with recombinant HMGB1 (1–5 μg/ml) did not lead to myocyte apoptosis and TNFα production. Exogenous TNFα induced a moderate pro‐apoptotic effect on the myocytes; an effect substantially potentiated by HMGB1. TNFα activated both JNK and NFκB. However, degree of TNFα–induced JNK activation was greater than NFκB in the presence of HMGB1. Inhibition of JNK diminished the myocytes apoptosis‐induced by either TNFα or TNFα/HMGB1 cocktail. A/R‐challenge to TLR4 deficient myocytes increased HMGB1 but not apoptosis, TNFα production and JNK activation.Conclusionsour results indicate myocyte HMGB1/TLR4 axis and TNFα work in concert to promote A/R‐induced myocyte apoptosis via JNK activation. (HSFO NA‐6316).
Histomorphometric characterization of thyroid follicles' areas on experimental hyperthyroidism and acupuncture treatment
Authors: Farinha Rodrigo , Cabral António , Machado Vanessa , Nolasco Varão , Cabrita A.M. Silvério 
Published: June 2021

Hyperthyroidism is caused by excess synthesis and secretion of thyroid hormone by the thyroid, which increases the metabolic rate. The experimental model of hyperthyroidism is conducted by an administration of an high dose of levothyroxine for two weeks. The aim of this study is to contribute to the histomorphometric characterization of thyroid follicles' areas on experimental hyperthyroidism.20 Wistar male rats were used, randomly distributed in four groups: control group, kept with no manipulation (Ctrl); group II, which received an administration of 250 mg/kg of levothyroxine by gavage 3 times a week (HT); group III received levothyroxine and acupuncture treatment (HT+AC); group IV, submitted only to the acupuncture treatment. After two weeks, all the animals were sacrificed and fragments from thyroid were collected and analyzed using ImageJ®. The points used for puncture were: ST09, ST36, HC4, RM23.When compared with the control group, we observed more frequently large follicles on group IV than in control group. The animals of group II and III have more often smaller follicles than those observed in control group.The results, although without statistical significance, suggest that acupuncture may have some effect on thyroid function.
Ethanol Interferes with Gene Regulatory Networks of Embryonic Stem Cells
Authors: Sanchez‐Alvarez Rosa , Gayen Saurabh , Vadigepalli Rajanikanth , Anni Helen 
Published: June 2021

Gestational exposure to ethanol may promote abnormalities in the fetus, including growth retardation, facial dysmorphology and mental disability, under the umbrella of Fetal Alcohol Spectrum Disorders (FASD). We studied the interference of ethanol with normal embryonic development in embryonic stem (ES) cells. Mouse ES cells (E14Tg2A) were cultured in feeder‐free conditions, and converted to neural lineages in adherent monolayer in the presence or absence of ethanol. High throughput BioMark microfluidic 48.48 dynamic array chips (Fluidigm) measuring 2,304 real time quantitative PCR assays were used to assess levels of transcription factors and target genes involved in cell fate commitment during cell differentiation. Our data show that during ES cell differentiation i) genes regulating pluripotency and self‐renewal (Sox2, Nanog, Oct4, Klf4, Rex1, Dax1) were downregulated, iii) neuroectoderm and neural markers (e.g., Cxcl12, Nrip1) were upregulated, and ii) ethanol exposure delayed these changes. Network analysis points to nodes and edges of the gene regulatory networks perturbed by ethanol during early differentiation that may be responsible for aberrant neuroectodermal development in FASD.Supported by TJU Pilot Research Award, Dept Funds, and Graham Foundation.
Reduced expression of tryptophan hydroxylase in the prefrontal cortex of a parkinsonian mouse model
Authors: Nayyar Tultul , Ferguson Marcus C , Ansah Twum A 
Published: June 2021

OBJECTIVEIn 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐treated mouse model of Parkinson's disease (PD), we have shown a significant decrease in the density of beaded type serotonin (5‐HT) axons and concentrations of 5‐HT in the prefrontal cortex (PFC). Here we studied the protein level of tryptophan hydroxylase (TPH) and beta arrestin (βAR) 1 and 2 in the PFC in MPTP treated mice.DESIGN AND METHODSMale C57BL/6J mice were treated with 4 doses of MPTP 20 mg/kg (i.p.) at every 2 hours and sacrificed after 3 and 16 weeks. The protein expression for TPH, βAR‐1 and ‐2 in the PFC and TPH in the raphe was studied by Western blot. 5‐HT cell bodies in the raphe were studied by immunohistochemistry.RESULTSMPTP‐treated mice have shown a significant decrease in TPH protein level in PFC and a significant increase in the raphe nucleus. Protein expression for β‐AR1 and β‐AR2 were also significantly decreased in PFC. Immunohistochemistry of 5‐HT neurons in the raphe nuclei with TPH antibodies showed reduced intensity of staining for 5‐HT cell bodies in medial raphe (MR) and slightly increased in dorsal raphe (DR) after MPTP treatment. The reduced density of TPH‐labeled 5‐HT neurons in the MR correlated well with our earlier report of preferential decrease in the density of thick beaded 5‐HT axons in the PFC which originate from MR.CONCLUSIONThese results suggest that TPH is a major target of MPTP‐induced alterations of serotonergic function in PFC with a possible link to depression. Targeting TPH and related signaling events may afford therapeutic advantages for the management of depression in PD. Supported by NIH SNRP/NINDS grant NS041071.
EFFECT OF PROPOLIS WITH TOPICAL ADMINISTRATION ON ACID‐INDUCED COLITIS IN RATS
Authors: Ozturk Haluk , Surer Ilhami , Surer Hatice , Demirbag Suzi , Guven Ahmet , Atabek Cuneyt , Caliskan Bahadir 
Published: June 2021

PURPOSEPropolis, which is a specific product of honeybee hive exhibits potential antioxidant and anti‐inflammatory properties. This study was designed to determine the effects of propolis on acid‐induced experimental colitis model in rats.METHODSThe experimental acid induced colitis was performed in 56 Wistar‐Albino rats according to Mann and Demers. Then rats were divided into two equal groups (Sl‐saline irrigation and Pl‐propolis irrigation). After preliminary saline irrigation in all rats either propolis (1.5 ml–100 mg/kg) or saline enema (1.5 ml) was administered by rectal route after acetic acid induction/In both groups irrigation procedure was performed in every 12 hours until colonic resection time. At 3rd &#8211; 7th &#8211; 10th and 14th post operative days rats were killed and distal colonic segments were harvested to determine the histopathological changes and tissue levels of malondialdehyde (MDA).RESULTSSeverity of the mucosal injury in Pl group was significantly lower when compared with the Sl group. Additionally MDA levels in Sl group was higher statistically significant than Pl group.COCLUSIONTopical administration of propolis as a rectal enema has significantly improved rectal mucosal restoration rate and both histopathological parameters and MDA levels on acid‐induced colitis model.
Critical role of Paneth cell‐derived IL‐17A in hepatic ischemia and reperfusion injury
Authors: Lee H Thomas , Kim Mihwa , D'Agati Vivette D , Park Sang Won 
Published: June 2021

Hepatic ischemia and reperfusion (IR) injury is a major clinical problem with frequent extra‐hepatic complications including intestinal dysfunction and acute kidney injury (AKI). We aimed to determine the mechanisms of hepatic IR‐induced systemic complications. Mice subjected to 60 min of hepatic IR not only developed severe hepatic injury but also developed significant AKI and small intestinal injury. Hepatic IR induced small intestinal Paneth cell degranulation and increased IL‐17A levels in portal plasma and small intestine. IL‐17A neutralizing antibody treatment or genetic deletion of either IL‐17A or IL‐17A receptors significantly protected against hepatic IR‐induced acute liver, kidney and intestinal injury. Leukocyte IL‐17A does not contribute to organ injury as wild type splenocytes infused into IL‐17A deficient failed to exacerbate liver and kidney injury after hepatic IR. Laser capture micro‐dissection of Paneth cells showed significant IL‐17A mRNA induction after hepatic IR. Finally, wild type mice treated with dithizone to deplete Paneth cells or Paneth cell deficient (Sox9flox/flox;VilCre) mice were protected against hepatic, renal and intestinal injury following liver IR. Taken together, the results show that Paneth cell derived IL‐17A plays a critical role in hepatic IR injury and extra‐hepatic organ dysfunction. Modulation of Paneth cell dysregulation may have therapeutic implications by reducing systemic complications arising from hepatic IR.Supported by Department of Anesthesiology, Columbia University.
Age‐related differences in cerebrovascular reactivity in response to COX inhibition
Authors: Barnes Jill N , Hines Casey N , Nicholson Wayne T , Schmidt John E , Katusic Zvonimir S , Joyner Michael J 
Published: June 2021

Reduced cerebral blood flow and reactivity may explain age‐related changes in cognitive function. We examined cerebrovascular reactivity, and the potential role of prostaglandins, in young and old healthy humans. Middle cerebral artery velocity (MCAv) responses to stepped hypercapnia were measured in young (26±2y; 6M/5F) and old (66±2y, 3M/4F) adults before (PRE) and 90 min after (POST) oral indomethacin (1.2mg/kg). To account for any changes in blood pressure, cerebrovascular conductance index (CVCi) was calculated as the MCAv divided by mean arterial pressure. Cerebrovascular reactivity slopes were calculated using linear regression between either MCA velocity or CVCi and end‐tidal CO2. There were no differences between young and old adults in height, weight, BMI, or brachial blood pressures. Young adults demonstrated greater MCAv (53.7±6.7 vs. 32.0±3.3), MCAv reactivity (1.62±0.21 vs. 0.94±0.10), and CVCi (0.66±0.08 vs. 0.39±0.04) compared with old adults at PRE (P<0.05 for all). In both young and old adults, MCAv, MCAv reactivity, CVCi, and CVCi reactivity decreased between PRE and POST measurements. Furthermore, any age‐related differences in these cerebrovascular variables were abolished by indomethacin. These results suggest that cerebral blood flow and cerebrovascular reactivity is attenuated in aging adults and that this reduction may be mediated by prostaglandins.NIH: AG16574‐11PP2
Role of c‐Src tyrosine kinase in airway smooth muscle contraction
Authors: Humber Brent , Tazzeo Tracy , Janssen Luke 
Published: June 2021

One component of asthma is airway hyperactivity whereby the airway smooth muscle (ASM) cells abnormally constrict (to a greater degree) in the presence of an excitatory stimulus. It is not known whether serotonin (5‐HT) and acetylcholine (ACh) differentially impact ASM contraction via c‐Src phosphorylation (activation).This study investigated the contractile responses to ACh and 5‐HT in the presence of a non‐selective tyrosine kinase inhibitor (genistein) and Src‐family kinase inhibitors (PP1 and PP2). We also examined whether these contractile agonists influenced c‐Src phosphorylation. Bovine tracheal ASM segments (0.5cm × 3cm) were dissected, mounted vertically in an organ bath and the isometric changes in tension were measured. Segments were flash frozen and subjected to western blotting. PP1 and PP2 significantly reduced the contractile response of 5‐HT by 73% and 70% respectively, but did not change the response to ACh. Genistein completely abolished responses to 5‐HT but did not affect responses to ACh. Western blotting data suggests increased c‐Src phosphorylation in response to both 5‐HT and ACh.These data suggest c‐Src tyrosine kinase activation is uniquely sensitive to 5‐HT (relative to ACh) and might be a key molecular player in ASM contraction when ASM cells are stimulated by the 5‐HT G‐protein coupled receptor.Research Support: CIHR
Acute Respiratory Distress Syndrome (ARDS): Are corticosteroids harmful in lung injury
Authors: Chupin Cecile , Lavoie Jacynthe , Privé Anik , Brochiero Emmanuelle , Berthiaume Yves 
Published: June 2021

ARDS is a rapidly evolving lung injury that is linked with permeability oedema and excessive inflammation, leading to a severe oxygenation defect. Albeit there has been significant progress in survival, ARDS mortality remains ~ 40 %. Glucocorticoids therapy has been proposed to decrease the inflammatory response, but its usage remains controversial.The objective of this study was to evaluate the impact of dexamethasone treatment (dex; 0.5 mg/kg/d) on the in vivo evolution of bleomycin‐induced (bleo; 4 U/kg) lung injury in NMRI mouse. Treatment with dex did not decrease the mortality, the weight loss, the wet/dry ratio, the severity of epithelial injuries and the inflammatory infiltrating of neutrophils induced by bleo. To better evaluate the lack of response to dex, the impact of dex on the repair process of primary epithelial cells was studied. Our results show that dex inhibits the closure of mechanical wound. This effect of dex is not related to a default of proliferation, or an activation of apoptosis. This inhibitory effect of dex on wound closure is associated with an increase in cell adhesion suggesting that its effect could be related a modulation of the cytoskeleton.Our results indicate that dex does not decrease the severity of lung injury model and might slow its recovery by preventing proper repair of the alveolar epithelium.Supported by RSR‐FRSQ, FCFK, IRSC.
Functional specialization in the forelimbs of two digging mammals: the American badger (Taxidea taxus) and groundhog (Marmota monax)
Authors: Moore Alexis Lee , Butcher Michael 
Published: June 2021

Limb muscles are often studied for their properties related to locomotion, but studies of architectural properties in limb muscles of animals specialized for other behaviors, such as digging, are less common. This study quantified muscle architectural properties in the forelimbs of badgers (Taxidea taxus) and groundhogs (Marmota monax), two digging species from phylogenetically different clades (Carnivora vs Rodentia), and estimated maximum force production and power output of their forelimb muscles. Architectural properties measured included: muscle mass, belly length, volume, physiological cross‐sectional area, fascicle length and pennation angle. Both species showed massive elbow extensors and digital flexors that together accounted for approximately 60% of intrinsic forelimb muscle mass. The elbow extensors displayed a low degree of pennation with longer fascicles, an architecture consistent with appreciable shortening capability and high power. The digital flexors showed relatively greater pennation and shorter fascicle lengths in addition to compartmentalization of muscle heads for both force production and range of contraction. These findings suggest both the elbow extensors and digital flexor muscles in badgers and groundhogs have the capacity for high force during scratch‐digging, while the elbow extensors are better suited for high power during rapid digging movements. URC #3‐11.Grant Funding Source: URC, Youngstown State University
RNA helicase Mov10 is a potent inhibitor of HIV or retrovirus infectivity and retrotransposition of endogenous mammalian retroviruses
Authors: Furtak Vyacheslav , Unutmaz Derya 
Published: June 2021

The objective of this research work is to characterize antiviral and anti‐retrotransposon activity of RNA helicase Mov10. We recently reported that ectopic expression of Mov10 restricted the production of HIV‐1 and other lentiviruses as well as the gammaretrovirus, murine leukemia virus. 293T cells were transfected with retrovirus coding plasmid and Mov10 or control plasmid followed by infectivity test. HIV produced in the presence of high levels of Mov10 is restricted at the pre‐reverse transcription stage in target cells. To determine if Mov10 can also modulate transposition of retroviral elements in human genome, we transfected HeLa cells with retrotransposon coding plasmid that contained neomycin resistance cassette with or without Mov10 expressing plasmid. We then quantitated retrotransposon integration frequency by counting G418‐resistant cellular colonies in the presence or absence of Mov10 transfection. Retrotransposition of LINE‐1, MusD and IAP was significantly reduced by Mov10 in a dose dependent manner. These retroelements also showed sensitivity to restriction by other proteins found within the mRNA processing bodies (P‐bodies) such as Ago‐2 and Rent1. These findings suggest a potentially important role for cytoplasmic RNA processing machinery in retroviral infectivity, production and control of mobile genetic elements.This work was supported by NIH Grant R21 AI078839 to D.U.