bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinct Role of Endothelial Caveolae in Contraction and Relaxation Responses of Aortas from Pregnant Normotensive and Hypertensive Rats
Authors: Troiano Jéssica Antonini , Graton Murilo Eduardo , Potje Simone Regina , Gonçalves Emily Thalia , de Oliveira Fonseca Zanardo Jéssica Luiza , Benevides Priscila Scarpim , Antoniali Cristina 
Published: June 2021

We evaluated the role of endothelial caveolae in contraction and relaxation of aortas of Wistar and spontaneously hypertensive rats (SHR) at the end of pregnancy. The quantification of the endothelial caveolae number in the absence or presence of methyl‐β‐ciclodextrin (DEX,10 mM/L) in aortas from non‐pregnant (NP) and pregnant (P) Wistar and SHR with 12 weeks old (n= 5) was assessed by electronic microscopy. Aorta rings from different groups (n= 5) were stimulated with cumulative concentrations (1 nM/L to 10 μM/L) of phenylephrine (PE) or acetylcholine (Ach) in the absence or presence of DEX (10 mM/L). We performed the analysis of caveolin‐1 (cav‐1) and p‐cav‐1 expression by Western Blot in aortic homogenates (n= 5). Ethics committee FOA‐UNESP proc. 00730/2015. The results were compared among groups (ANOVA, p <0.05). Hypertensive NP rats present a reduced number of caveolae in aortas when compared to aortas from Wistar NP. Wistar P has a lower number of caveolae in aortas when compared to aortas from Wistar NP, but the number of caveolae was not altered between aortas of SHR P and SHR NP. DEX was able to reduce the number of caveolae in aortas only in the NP groups of normotensive or hypertensive rats. Vascular reactivity assays showed that in the presence of DEX the aortas of the Wistar NP and SHR NP groups had an increase in the contractile response to PE as well as a reduction in the potency of ACh. However, in aortas of the Wistar P and SHR P groups had no change in the contractile response for PE and ACh. p‐cav‐1/cav‐1 expression is decreased in aortas of SHR NP when compared to Wistar NP. Pregnancy does not alter p‐cav‐1/cav‐1 expression in aortas of Wistar rats, but it increases cav‐1 phosphorylation in SHR aortas. These results showed that pregnancy does not alter the reduced number of caveolae in aortas of hypertensive rats. Due to the reduced number of caveolae in aortas of pregnant rats, DEX would have no effect on aortic reactivity to PE or ACh. Although the reduced number of caveolae, the increased p‐cav‐1 expression in aortas of SHR P could be associated with increased eNOS activity and consequently lower NO‐dependent reactivity, from aortas to PE.Support or Funding InformationFAPESP 2015/09373‐0; 2016/22180‐9; 2018/10635‐7 and CAPES.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Acute Calcitriol‐Mediated PTH Suppression is Attenuated by High Phosphate Diet in Experimental Model of CKD
Authors: Lee Lok Hang , Turner Mandy , Ward Emilie , Laverty Kim , Pruss Cynthia , Holden Rachel , Adams Michael 
Published: June 2021

BackgroundChronic kidney disease (CKD) patients have impaired phosphate and calcium excretion as well as vitamin D deficiency, which exacerbates secondary hyperparathyroidism (SHPT). A decrease in renal CYP27B1 conversion of calcifediol leads to reduced levels of calcitriol. SHPT leads to increased bone resorption and is a risk factor for vascular calcification and cardiovascular disease in the CKD population. The effectiveness of calcitriol in managing SHPT is problematic, as significant resistance develops with chronic therapy; a condition that can lead to parathyroidectomy.AimDetermine the time course and impact of increasing dietary phosphate on calcitriol‐induced suppression of PTH in experimental CKD.MethodsIn Sprague Dawley rats (N=10), a 0.25% adenine 0.5% phosphate diet was fed for 4–5 weeks to generate stable CKD. A single oral calcitriol dose (160ng/kg) was given pre‐CKD, and at 1, 3, and 5 (off adenine) weeks of CKD induction (0.5% dietary phosphate). From 7–8 weeks rats were given increased dietary phosphate (1.0%) and the response to calcitriol was re‐assessed. Changes in circulating PTH, fibroblast growth factor 23 (FGF‐23), calcium and phosphate in response to the biweekly sham or calcitriol dosing were assessed at 0, 4, 8 and 24 hours.ResultsIn CKD rats, PTH increased from 80±25.8 pg/mL to 221±66.7 pg/mL (week 5) and FGF‐23 from 421±26.0 pg/mL to 6803±1510.2 pg/mL (week 5). The two week 1% phosphate markedly increased PTH to 1342±310 pg/mL (8 weeks) and FGF‐23 to 14490±4980.8 pg/mL (7 weeks). In CKD rats on a low phosphate diet, the biweekly calcitriol dose reduced PTH by up to 44% and raised FGF‐23 by 82% whereas in rats on high dietary phosphate PTH was no longer responsive to calcitriol suppression.ConclusionResponses to calcitriol therapy were attenuated with increasing dietary phosphate and increasing CKD severity. This study supports the importance of dietary phosphate restriction in the CKD population to limit the impact of PTH responsiveness and mineral bone disease in this population.SignificanceCharacterization of calcitriol resistance will help to develop new dosing strategies for vitamin D receptor agonists in this population and prevent SHPT and parathyroidectomies.Support or Funding InformationFunded by the Canadian Institutes of Health ResearchThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Increased sodium transporters in distal nephron segments are associated with clozapineinduced hypertension
Authors: Ren Zhiyun , Yu Yanting , Zhu Gangyi , Asico Laureano , Jose Pedro , Wang Xiaoyan 
Published: June 2021

Dopamine receptor subtype 4 (D4R) antagonists, such as clozapine, are used in the treatment of schizophrenia. A common side effect of clozapine is hypertension but the mechanism of the clozapine‐induced hypertension is unknown. D4R plays an important role in blood pressure (BP) regulation; deletion of the D4R gene in mice causes hypertension. To determine if renal mechanisms are involved in clozapine‐induced hypertension, we characterized the distribution of D4R in mouse kidney and measured BP, water and sodium balance, and renal protein expression of sodium transporters in clozapine‐ and vehicle‐treated mice. D4R (immunocytochemistry) was mainly located in thick ascending limb, distal convoluted tubule and cortical and medullary collecting ducts; there is slight staining of D4R in the proximal convoluted but not straight tubule. Clozapine (20mg/kg/day) or vehicle was delivered subcutaneously to adult male C57BL/6J mice for seven days via osmotic mini‐pump (n=5/group). In clozapine‐treated mice, systolic (110±0.5, mm Hg, under anesthesia) and diastolic BPs (76.6±1),) were elevated, relative to vehicle‐treated mice (SBP=97.6±1.6, DBP=69.5±2.3). Food and water intake, body weight, serum electrolytes and creatinine, urine volume, and creatinine clearance were similar in the two groups. The sodium excretion tended to decrease while sodium excretion and blood pressure plot in clozapine‐treated mice was shifted to the right of the vehicle‐treated mice. Renal protein expressions (immunoblotting) of sodium hydrogen exchanger 3 and sodium phosphate cotransporter 2 were similar in clozapine‐ and vehicle‐treated mice. However, the renal protein expressions of sodium potassium 2 chloride cotransporter (180±21, % of control) and sodium chloride cotransporter (171±22% ), and the three subunits of epithelial sodium channel, α (140±7%), β (166±21%) and γ (55 kDa=130±7%, 85kDa=114±10% ), were greater in clozapine‐than vehicle‐treated mice. Renal protein expression of a‐sodium potassium ATPase was also slightly increased (118±4%) in clozapine‐treated mice. These findings suggest that inhibition of D4R by clozapine increases sodium transporters in distal nephron segments. Furthermore, a similar increase in the protein expression of sodium chloride cotransporter was also found in the immortalized mouse renal distal convoluted tubule cells in vitro with inhibition of D4R with its siRNA and antagonists. Thus, inhibition of renal D4R may cause the impaired sodium excretion that may be responsible for the increased blood pressure in clozap‐inetreated mice.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
α7‐nAChR‐Mediated Therapeutic Angiogenesis Accounts for the Advantageous Effect of Low Nicotine Doses Against Myocardial Infarction in Rats
Authors: Youssef Mahmoud E , El‐Mas Mahmoud M , Abdelrazek Heba M , El‐Azab Mona F 
Published: June 2021

Angiogenesis accelerates tissue regeneration in a variety of ischemic conditions including myocardial infarction (MI) and constitutes a valuable approach for post‐MI repair. Here we investigated whether angiogenesis promotion induced by α7‐nicotinic acetylcholine receptors (α7‐nAChRs) mitigates histopathological, electrocardiographic, and molecular consequences of MI in rats. These profiles were evaluated in rats with isoprenaline (85 mg/kg/day i.p. for 2 days)‐induced MI and co‐treated subcutaneously with nicotine (20 μg/kg/day s.c.), PHA‐543613 (PHA, selective α7‐nAChR agonist, 20 μg/kg/day), methyllycaconitine (MLA, selective α7‐nAChR antagonist, 40 μg/kg/day) plus nicotine, or the vehicle for 16 consecutive days. Isoprenaline‐insulted rats showed (i) ECG signs of MI such as significant ST‐segment elevations and prolonged QT‐intervals, (ii) deteriorated left ventricular histopathological scoring and elevated inflammatory cell infiltration, (iii) reduced immunohistochemical expression of cardiac CD34, a biomarker of capillary density, (iv) decreased cardiac expression of iNOS and α7‐nAChRs, and (v) adaptive increases in cardiac HO‐1 expression and plasma angiogenic markers such as vascular endothelial growth factor (VEGF) and nitric oxide (NO). These effects of isoprenaline, except cardiac iNOS and α7‐nAChRs downregulation, were ameliorated in rats co‐treated with nicotine or the selective α7‐nAChR agonist PHA for 16 consecutive days. We also show that concurrent α7‐nAChR blockade by MLA reversed the ECG, histopathological, and capillary density effects of nicotine, thereby reinforcing the advantageous cardioprotective and anti‐ischemic roles of α7‐nAChRs in this setting. In conclusion, the activation of α7‐nAChRs with PHA or doses of nicotine in the microgram scale promotes neovascularization and offers a promising therapeutic strategy for MI.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Contribution of Ceramide Signaling to Activation of the mTORC1 Pathway and Calcification Nidus Formation in Coronary Arterial Smooth Muscle Cells
Authors: Bhat Owais M , Huang Dan‐Dan , Yuan Xinxu , Kukreja Rakesh C , Li Pin‐Lan 
Published: June 2021

The mammalian target of rapamycin complex 1 (mTORC1) signaling on late endosomes (LE)/lysosomes may control cargo selection, membrane biogenesis, exosome secretion and lysosome trafficking, which is fine controlled by lysosomal sphingolipids such as ceramide. This lysosomal sphingolipid‐regulated mTOR signaling may be a crucial molecular mechanism responsible for development of the arterial medial calcification (AMC) given the crucial role of exosome secretion from vascular smooth muscle cells (SMCs). In the present study, we used coronary artery SMCs (CASMCs) from Asah1fl/fl/SMcre mice with SMC‐specific deletion of lysosomal acid ceramidase (mouse gene code: Asah1) to demonstrate the role of lysosomal ceramide in mTOR signaling and arterial calcification. First, we demonstrated that mTORC1, a 289 kD cytoplasm protein is enriched in CASMCs by Western blot analysis and treatment of CASMCs isolated from Asah1fl/fl/SMcre mice with high Pi increased more calcium deposition compared to WT/WT cells as shown by the presence of Alizarin Red‐stained nodules. This calcium deposition was significantly decreased by specific mTOR inhibitor (Torin‐1) and by acid sphingomyelinase (Asm) inhibitor (Imipramine). Correspondingly, Asah1 gene deletion induced phenotypic change in Pi‐treated CASMCs, as depicted by decreased SM22‐α (SMC marker) expression in Western blot analysis, which was reversed by Torin‐1 or Imipramine. Using confocal microscopy, we further found that Pi markedly increased colocalization of mTORC1 with Lamp‐1, a lysosome targeting of mTORC1, but decreased colocalization of VPS16 with Lamp‐1, an indicative of multivesicular bodies (MVBs) interaction with lysosomes in CASMCs from Asah1fl/fl/SMcre mice, suggesting that activation of mTOR signaling inhibits lysosome trafficking or fusion with MVBs if AC was deficient. However, mTOR and Asm inhibition produced opposite effects on lysosome trafficking and interaction with MVBs compared to CASMCs treated with AC deficiency, further suggesting the role of ceramide‐mTOR signaling in lysosome trafficking or interactions with MVBs. Using nanoparticle tracking analysis, Pi‐induced excretion of exosomes (100–150 nm in size) were found to be significantly increased in CASMCs of Asah1fl/fl/SMcre mice compared to CASMCs from their control littermates. These results suggest that lysosomal ceramide‐mTOR signaling critically controls MVB fate and exosome release and that AC deficiency may lead to increased mTOR activation, thereby increasing exosome release and leading to calcification nidus formation in CASMCs.Support or Funding Information(Supported by NIH grants HL057244, HL075316 and DK120491)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Carbon Nanotubes and Crystalline Silica Stimulate Matrix Remodeling and Contraction by Inducing Myofibroblast Transformation in a Three‐Dimensional Culture of Human Pulmonary Fibroblasts: Role of Dimension and Rigidity
Authors: Ma Qiang , Hindman Bridget 
Published: June 2021

Pulmonary fibrosis is a poorlyunderstood pathologic condition. Carbon nanotubes (CNTs) are nanomaterials withpotentials for broad applications. CNTs can induce pulmonary fibrosis inanimals, a cause for concern for exposed workers and consumers. Giventhe large number of CNTs available on the market and the seemingly infinitenumber of ways these particles can be modified in ways that may affecttoxicity, in vitro models that can be used to quickly and effectively investigatethe relative fibrogenicity of CNTs are much needed. Here we analyzed thefibrogenic potentials of six CNTs of varying physical properties, as well ascrystalline silica, using two and three‐dimensional (2D and 3D, respectively) in vitro models. WI38‐VA13 human pulmonary fibroblasts were treated with CNTs orsilica, with TGF‐β1, a known inducer of fibroblastdifferentiation, as positive control. The cells were examined for fibroticmatrix alterations, including myofibroblast transformation, matrix remodeling, and matrix contraction. While all tested CNTs induced myofibroblastdifferentiation in 2D and 3D cultures, the 3D culture allowed the examinationof myofibroblast clustering, collagen deposition and rearrangement, celldivision, and matrix contraction in response to fibrogenic exposures, processescritical for fibrosis in vivo. At 1 μg/ml, multi‐walled carbon nanotubes (MWCNTs) elicit higherinduction of myofibroblast differentiation and matrix remodeling than single‐walledcarbon nanotubes (SWCNTs). Among MWCNTs, those with the highest and lowestaspect ratios produced the largest effects, which were comparable to those byTGF‐β1 and higher than those by silica. Thus, the 3D collagen‐based modelenables the study of matrix fibrotic processes induced by CNTs and silicaparticles directly and effectively. This in vitro approach to analyzingfibrogenic activities of inducers is applicable to a variety of fibrogenicagents including particles, fibers, nanomaterials, and soluble inducers.Support or Funding InformationSupported by a grant for Q.M. from the Health Effects Laboratory Division and the Nanotechnology Research Center at National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, USA.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Exercise training‐induced enhancement of coronary vasodilatory function is absent in rats lacking the transcription factor, Nrf2
Authors: Ballehr Kelsey Lynn , Park Hyerim , Restrepo Alexis , Dewell Isabella , Wahl John , Wahl Jake , Vega‐Figueroa Leilanie , McKinley‐Caspanello Carly , Maraj Joshua , Peterson William , Reid‐Foley Emily , Bedwell Kristin , Schwartz Kaley , Sadowsky Dylan , Delp Michael , Geurts Aron , Medarev Steven , Muller‐Delp Judy 
Published: June 2021

Nuclear factor (erythroid‐derived 2)‐like 2 (Nrf2) is a transcription factor that is crucial in maintaining cellular redox homeostasis. Aerobic exercise training has been reported to enhance vasodilatory responses of coronary arterioles through signaling that involves reactive oxygen species. We hypothesized that deletion of Nrf2 would alter vasodilatory responses of coronary arterioles and limit exercise training‐induced adaptations of coronary vasodilatory function. We exercise trained wild type (WT) Sprague‐Dawley rats, and their littermates that were lacking the Nrf2 gene (Nrf2KO). Rats were either exercise trained (EX) on a motor‐driven treadmill 5 days/wk or remained sedentary (SED) in their cages for 10–12 weeks. A mixed moderate aerobic and high‐intensity interval training protocol was utilized. At the end of the training period, coronary arterioles were isolated and vasodilatory responses to intraluminal flow (pressure differences from 2–60 cm H2O) and the exogenous nitric oxide donor, Dea‐NONO‐ate (1×10−9–1×10−4M), were evaluated. Endothelium‐dependent vasodilation to intraluminal flow was not altered by either deletion of Nrf2 or by exercise training. In contrast, endotheliumin‐dependent vasodilation to Dea‐NONO‐ate, was reduced in coronary arterioles from Nrf2 rats as compared to arterioles from WT rats (WT vs Nrf2 KO; P=0.054). Exercise training increased responsiveness to Dea‐NONO‐ate in arterioles from WT rats (WT EX vs WT SED; P<0.05), but not in arterioles from Nrf2KO rats. These data suggest that deficiency of Nrf2 alters the function of vascular smooth muscle, but not the function of the vascular endothelium in coronary arterioles. Exercise training increases the vasodilatory responsiveness of coronary arteriolar smooth muscle to nitric oxide, but not in the absence of Nrf2, suggesting that mechanisms of redox homeostasis and nitric oxide signaling interact in the smooth muscle of coronary arterioles.Support or Funding InformationNIH R15AG055029This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Selective disruption of IGF‐1 signaling in astrocytes up‐regulates soluble epoxide hydrolase and impairs EET‐mediated vasodilation
Authors: Kiss Tamas , Balasubramanian Priya , Tarantini Stefano , Fulop Gabor A , Yabluchanskiy Andriy , Csipo Tamas , Lipecz Agnes , Farkas Eszter , Sonntag William E , Csiszar Anna , Ungvari Zoltan 
Published: June 2021

Insulin‐like growth factor 1 (IGF‐1) exerts multifaceted protective effects on the cerebral microcirculation and age‐related reduction of circulating IGF‐1 levels is known to promote cognitive decline. Astrocyte‐mediated neurovascular coupling (NVC), which adjusts cerebral blood flow to increased energy requirements of activated neurons, plays a critical role in the maintenance of normal neuronal function. Although previous studies demonstrate that circulating IGF‐1 deficiency significantly impairs NVC, the role of astrocyte‐specific effects of IGF‐1 in regulation of NVC is not completely understood. To test the hypothesis, that disruption of IGF‐1 signaling specifically in astrocytes impairs pathways involved in regulation of cerebral blood flow regulation we assessed changes in local cerebral blood flow elicited by contralateral whisker stimulation in mice with astrocyte‐specific knock‐down of IGF‐1 receptor 1 (Igfr1f/fGfap‐Cre), and respective controls using laser speckle contrast imaging. We found that NVC responses were significantly impaired in Igfr1f/fGfap‐Cre mice (4±1%) as compared to that in control mice (10±1%). In control mice NVC responses were significantly decreased by pharmacological inhibition of epoxyeicosatrienoic acid (EET) synthesis (MS‐PPOH) (4±1%). In contrast, NVC responses in Igfr1f/fGfap‐Cre were unaffected by MS‐PPOH. Analysis of expression of genes enriched in astrocytes that have function al relevance for CBF regulation revealed that in Igfr1f/fGfap‐Cre mice expression of soluble epoxy hydrolase was up‐regulated both at the mRNA and protein level. Pharmacological inhibition of soluble epoxy hydrolase improved NVC responses in Igfr1f/fGfap‐Cre mice. Collectively, our findings support the concept that normal astrocyte function is essential for the adequate NVC responses and provide evidence that decreased IGF‐1 input to astrocytes results in increased degradation of EETs. impairing functional hyperemia. We propose that these findings have relevance for the pathogenesis of cognitive decline associated with age‐related IGF‐1 deficiency.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
An Ex Vivo Model for Investigating Transplanted Pancreatic Islet Vascular Integration
Authors: Dolan Robert M , Hodges Nicholas A , Phelps Edward A , Murfee Walter L 
Published: June 2021

Vascular integration of transplanted pancreatic islets is imperative for islet graft survival and treatment of type 1 diabetes. Despite only comprising 1–4% of the pancreas mass, islets receive 15% of the pancreatic blood flow, because the microvascular network within the islet is much denser than the surrounding exocrine tissue. We were motivated to better understand how islets influence local microvascular networks and how networks form connections with islets in experimental models that mimic the complex environment of real tissue. Recently, our laboratory established the rat mesentery culture model as a tool to investigate real‐time cell dynamics involved in microvascular growth. An advantage of the model is the ability to observe blood vessel, lymphatics and immune cells. The objective of this study is to establish the rat mesentery tissue culture model as a tool to investigate islet tissue integration. Islets harvested from Sprague Dawley rats were DiI labelled and seeded onto adult male Wistar rat mesentery tissue at an approximate density of 20 islets per tissue and then cultured in MEM with 1% PenStrep and 10% fetal bovine serum for 3 days. After culture, DiI positive islets remained intact. In avascular regions, radial lectin positive capillary sprouts with DiI labeling were observed to be forming from islets. In pre‐vascularized regions, lectin positive capillary sprouts around islets connected with capillaries from pre‐existing networks. Our results establish the rat mesentery culture model as a platform for tracking cell dynamics associated with islet transplantation.Support or Funding InformationNIH R01AG049821This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.