bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temporally distributed mechanisms for skeletal muscle microvascular rarefaction in metabolic syndrome (674.9)
Authors: DeVallance Evan , Chantler Paul , Goodwill Adam , Butcher Joshua , Olfert I. , Brock Robert , Frisbee Jefferson 
Published: June 2021

Evolution of metabolic syndrome (MetSyn) and its constituent pathologies is associated with a gradual reduction in skeletal muscle microvessel density (MVD), known as rarefaction. While contributing to elevated vascular resistance at high metabolic demand and impairing mass transport/exchange, the temporal development of rarefaction and the contributing mechanisms which lead to the progressive microvessel loss are critical areas for investigation. Our studies demonstrate that overall reductions to MVD in skeletal muscle of obese Zucker rats (OZR) are well predicted by a chronic loss in vascular nitric oxide (NO) bioavailability. However, prior to any loss in NO, skeletal muscle arterioles from OZR exhibit an early shift in ROS, inflammatory biomarkers and arachidonic acid metabolism, resulting in increased production of TxA2. This increases venular leukocyte adhesion and causes a second, localized oxidant pulse, which initiates microvascular degradation in post‐capillary venules that is strongly associated with plasma MCP‐1 levels. If NO bioavailability is maintained (TEMPOL) after the initial increase in TxA2 and microvessel loss, the total rarefaction magnitude is blunted. Alternately, if actions of TxA2 are chronically inhibited, the initial rarefaction never develops and the subsequent secondary pulse (from NO reductions) is strongly muted. A similar muting of the initial and secondary pulse of rarefaction is manifested if TNF‐α production is inhibited (pentoxifyllene). These results suggest that microvessel rarefaction in OZR represents the integration of an early mild vessel loss that is dependent on TxA2, which creates an environment for the extensive rarefaction that is dependent on low NO bioavailability.Grant Funding Source: Supported by National Institutes of Health and American Heart Association
The effects of different types of adipose tissue on vascular function in carotid artery from mouse (677.7)
Authors: Laskowski Marta , Golubinskaya Veronika , Johansson Maria , Nilsson Holger 
Published: June 2021

Perivascular adipose tissue (PVAT) secretes the dilator substance “adipocyte‐derived‐relaxing‐factor” (ADRF) that has been shown to act mainly through voltage‐dependent (KV) and ATP‐dependent (KATP) potassium channels (K). Malfunction in ADRF may contribute to the metabolic syndrome. A recently suggested ADRF candidate is hydrogen sulfide (H2S) generated by the enzymes CSE, CBS and 3MST.We have here investigated the effect of ADRF and H2S from three different kinds of adipose tissues (AT) on mouse carotid arteries, and probed the mechanisms involved using specific blockers.Mesenteric, subcutaneous and brown AT were placed on vessel segments. Myography was used to investigate contractile responses to the α1‐receptor agonist phenylephrine with and without blockers of KV7 (XE991), KATP (glibenclamide), KV (4‐AP) or generally reducing K+ currents by elevated K+ concentration (KPSS). Na2S was used as H2S donor. DL propargylglycine (PAG) was used as CSE blocker. H2S measurements were performed by a selective electrode.Subcutaneous AT, but not mesenteric or brown AT, had an anti‐contractile effect that was not affected by XE991, 4‐AP or KPSS, but slightly attenuated by glibenclamide. Na2S caused dilatation that was reduced by XE991 but not by PAG. No H2S could be detected in any of the AT supernatants.These results give novel insight into the differences in ADRF pathways in different vascular beds and species, which makes other pathways, such as Ca2+‐channels, an interesting target for further examination. Excluding H2S as the dilator substance also makes it necessary to investigate other ADRF candidates.
Two‐dimensional model for prediction of arteriolar NO/O2 modulation by spatiotemporal variations in cell‐free layer (678.13)
Authors: Kim Sangho , Ng Yan Cheng , Namgung Bumseok 
Published: June 2021

The role of cell‐free layer (CFL) in modulating nitric oxide (NO) and oxygen (O2) transport has been of particular interest in many microcirculatory studies. Despite the significant roles of CFL in balancing NO/O2 bioavailability in arteriolar tissue, many of previous numerical approaches have relied on a one‐dimensional steady‐state model for simplicity. However, these models are incapable of providing information on the influence of spatiotemporal variations in CFL on the NO/O2 transport under dynamic flow conditions. Therefore, the present study proposes a new two‐dimensional transient model capable of predicting NO/O2 transport modulated by dynamic changes in the CFL width. The CFL width data were obtained from an in vivo experiment performed in the rat cremaster muscle. Our new model revealed that the NO bioavailability could be inversely related to the CFL width. The enhancement of NO production by greater wall shear stress with a thinner CFL could dominate the diffusion barrier role of the CFL preventing NO scavenging by RBCs. In addition, the NO/O2 availability along the vascular wall was not homogeneous and highly regulated by dynamic changes of the local CFL width variation. The time‐averaged spatial variations of the CFL widths on opposite sides of the arteriole exhibited a significant inverse relation. This asymmetric formation of CFL resulted in signifcantly imbalanced NO/O2 bioavailability in the tissues on opposite sides of the arteriole. This work was supported by NMRC/CBRG/0019/2012.Grant Funding Source: Supported by NMRC/CBRG/0019/2012.
Effect of chronic fish oil supplementation on renal function parameters of mice fed with a high fat or a high carbohydrate diet (689.9)
Authors: Fernandez Ricardo , Pequito Danielle , Coelho Isabela 
Published: June 2021

Fish oil (FO) supplementation, rich in n‐3 PUFA, has a positive effect on various diseases, including cancer, kidney diseases and diabetes. High fat (HFD) and/or high carbohydrate (HC) diets promote obesogenic effects and induce insulin resistance.The objective of this study was evaluate the effect of chronic fish oil supplementation on renal function parameters of mice fed with a HFD or a HC diets. Six weeks male mice were divided in three groups and fed with different diets during eight weeks: regular rodent chow (S), HC or HFD. After this, they were supplemented orally for 30 days with FO, 1g/kg body weight. Renal function parameters, urinary excretion of TXB2 and PGE2, immunolocalization of vimentin, desmin, α‐SMA and PCNA, and intraperitoneal glucose tolerance test were measured in all groups. Fasting glucose levels was significant higher in HFD vs S (139.6±6.2 mg/dL vs 104.5±5.5) (n=13).The HFD group present glucose intolerance, an effect that was not modified by fish oil supplementation. Plasma insulin levels were similar between the groups. Glomerular filtration (creatinine clearance) was lower in HC (0.63±0.10ml/min/kg) and HFD (0.78±0.1) groups if compared to S group (1.58±0.4) (p<0.01, n=10). FO supplementation did not induced significant changes in this parameter. Urinary excretion of TXB2 was also significantly lower in HC (2.0±0.4pg/min) and HFD (2.3±0.6) than S (11.3±3.3). The mean microalbuminuria level (expressed as urine albumin‐creatinine ratio) in the C group was 11.06±2.16ng/mg, a value that increased to 18.24±2.74 in HC and 35.65±7.32 in HFD. Fish oil supplementation in HFD partially reverted the increase in microalbumin excretion (21.33±1.33).The intrarenal expression of vimentin was significantly higher in the interstitium of HC and HFD groups, and in HFD tubules, an effect reverted by FO supplementation. In summary, FO supplementation partially reverted renal alterations induced by HC and HFD diets.Grant Funding Source: Supported by CAPES (Brazil)
Steviol retards renal cyst growth through reduction of CFTR expression and inhibition of epithelial cell proliferation in a mouse model of polycystic kidney disease (690.2)
Authors: Chatsudthipong Varanuj , Yuajit Chaowalit , Muanprasat Chatchai , Kittayaruksakul Suticha , Fedeles Sorin , Gallagher Anna‐Rachel , Somlo Stefan 
Published: June 2021

Cyst growth in ADPKD is associated with cAMP‐activated proliferation of cyst‐lining epithelial cells and transepithelial fluid secretion into the cyst lumen via CFTR chloride channel. It will eventually lead to renal insufficiency and renal failure for which no effective treatment is currently available. We previously reported that steviol retards MDCK cyst growth by inhibiting CFTR channel activity and promoting proteasomal‐mediated CFTR degradation. However, the MDCK cells do not carry the mutated PKD genes and do not recapitulate the complexity of PKD pathogenesis. Therefore, it is imperative to examine the effect of steviol in animal model that closely resembles PKD. In this study, we determined the effect of steviol on renal cyst growth in an orthologous mouse model of human ADPKD (Pkd1flox/flox :Pkhd1‐Cre). The results showed that daily treatment with both 200 mg/kg BW of steviol and 1,000 mg/kg BW of stevioside for 14 days markedly decreased kidney weight and cystic index in these mice. Surprisingly, only steviol markedly reduced blood urea nitrogen and creatinine values. It also reduced cell proliferation but had no effect on cell apoptosis. In addition, steviol suppressed CFTR and mTOR/S6K expressions but stimulated AMP‐activated protein kinase (AMPK) in renal cyst‐lining epithelial cells. These findings indicate that steviol slows cyst progression in PKD mouse model, in part, through the activation of AMPK which subsequently inhibits both CFTR expression and renal epithelial cell proliferation via mTOR/S6K pathway. Most importantly, steviol could markedly improve kidney function in a mouse model of PKD. Steviol thus has potential application for further development as therapeutic compound for the treatment of polycystic kidney disease.Grant Funding Source: Supported by Thailand Research Fund and Faculty of Science, Mahidol University, Bangkok, Thailand
Adventitial NADPH oxidase‐4 in vascular oxidative stress (693.12)
Authors: Deng Arlinda , Nguyen Huy , Adams Michael , Wang Hui Di 
Published: June 2021

BACKGROUND: Many types of hypertension are associated with increased level of angiotensin II and vascular oxidative stress. Previously, we have shown that NOX2, an adventitial NADPH oxidase (NOX) isoform, generates reactive oxygen species in cardiac vascular system. Although NOX4, as another major isoform of NOX, has been reported to generate reactive oxygen species and play a detrimental role, current publications allude to the possibility that NOX4 may play a beneficial role in the blood vessels. The current project examined this aspect by investigating the expression of adventitial NOX4 and reactive oxygen species.OBJECTIVE: The objective of this study is to test our hypothesis that the expression of adventitial NOX4 would not increase vascular ROS in Angiotensin II‐induced hypertension.METHOD: Four C57BL and NOX2 knockout mice, sixteen to eighteen weeks of age, were separated into two groups, a normotensive and Angiotensin II infused group. Angiotensin II infused animals developed hypertension. Thoracic aortas were sterilely removed, embedded in paraffin and then fixed on glass slides as 5µm thick sections. Expression of 3’‐nitrotyrosine, a reactive oxygen species indicator, NOX2, and NOX4 were determined by immunoflorescence method.RESULTS AND CONCLUSION: Similar to NOX2, NOX4 is expressed in both endothelium and adventitia of the aorta. The level of NOX4 in the Angiotensin II‐infused hypertensive is greatly increased about seven times in comparison to normotensive group. 3’‐Nitrotyrosin levels are increased in Angiotensin II infused mouse aorta segments. However, Angiotensin II induced hypertension and NT is not increased in NOX2 knockout mouse while there is significant amount of NOX4 is still expressed. In conclusion, our data indicate that NOX2 but not NOX4 contributes to vascular production of reactive oxygen species and hypertension.Grant Funding Source: Brock University
The role of amiloride‐insensitive sodium transport in alveolar fluid homeostasis (695.2)
Authors: Chupin Cécile , Rozowsky Simon , Kuebler Wolfgang 
Published: June 2021

Under both normal and pathological conditions, the lung fluid balance across the alveolar epithelial barrier is mainly regulated by active sodium transporters. Previous work has largely focused on the critical role of ENaC, yet ~60% of alveolar fluid clearance in rats or humans is amiloride insensitive. We decided to explore the role of the amiloride‐insensitive sodium cotransporters SGLT1 (Na+‐glucose co‐transporter 1) and SNATs (Na+‐coupled neutral amino acid transporters) in the intact lung. In isolated perfused rat lungs, we determined alveolar fluid clearance (AFC) using a double indicator dilution technique and probed for the role of SGLT1 and SNATs by addition of appropriate cotransporter substrates or inhibitors. While addition of the SNAT substrate L‐alanine did not affect basal AFC, it rescued AFC in lungs pre‐treated with amiloride, and this response was blocked by the SNAT inhibitor HgCl2. Analysis of bronchoalveolar lavage fluid revealed > 2‐fold of L‐alanine in the epithelial lining fluid compared to plasma level. RT‐PCR identified mRNAs for all 6 SNAT isoforms in whole lung, yet in alveolar epithelial cells, only SNAT 2 and 5 mRNA and protein were detected. In contrast, no functional involvement of SGLT1 in AFC was detected. These results indicate a new role for SNATs in AFC which becomes unmasked when ENaC is inhibited. SNAT2 and SNAT5 may represent novel targets for the resolution of pulmonary edema.Grant Funding Source: Funded by CIHR MOP # 245251
Cell confluency modulates cortical stiffness of human bone marrow endothelial cells (696.3)
Authors: Xie Leike , Sun Zhe , Hong Zhongkui , Brown Nicola , Glinskii Olga , Glinsky Vladislav , Meininger Gerald 
Published: June 2021

Little is known about mechanical properties of human bone marrow endothelial cells (HBMEC) as culture conditions change. Here, we used atomic force microscopy (AFM) to test the hypothesis that the degree of confluency modifies HBMEC stiffness. Individual cells were compared in non‐confluent and confluent phases. Two HBMEC lines HBME‐1 and HBMEC‐60 immortalized by different methods were cultured until reaching a desired growth phase. Primary HBMEC were used as a reference. Cell stiffness was calculated as Young’s Moduli using a modified Hertz model from AFM cell‐surface force curves. Actin expression was analyzed by immunofluorescence and western blotting (WB). Young’s Moduli were significantly increased in confluent vs non‐confluent HBME‐1 (6.79±2.58 vs 4.73±1.78 kPa, p<0.01) and HBMEC‐60 (4.25±1.14 vs 2.03±1.09 kPa, p<0.01) cells. Non‐confluent HBME‐1 exhibited similar stiffness to the primary HBME (5.49±2.06 kPa). Topographical images revealed denser networks of actin stress fibers in confluent cells. F‐actin labeling confirmed these results. WB data indicated elevated pan‐actin levels in confluent HBMEC. Thus, HBMEC stiffness is influenced by cell confluency in culture and enhanced stiffness is associated with increased actin expression, a major cytoskeletal component contributing to cell mechanical properties.Grant Funding Source: Supported by NIH Grants HL095486 (GAM), CA160461 (VVG), VA BLR&D Service Award 1I01BX000609 (VVG)
Upregulation of translational machinery in hypertrophied urinary bladder in rat with partial bladder outlet obstruction (704.4)
Authors: Shen Shanwei , Xia Chunmei , Lee Seong Ho , Kim Misong , Lysiak Jeffrey , Liu Miao , Zakari Madaniah , Steers William , Qiao Liya 
Published: June 2021

Partial bladder outlet obstruction (pBOO) causes considerable remodeling of the urinary bladder resulting in bladder organ hypertrophy. The serine/threonine protein kinase Akt serves as a convergent point in signaling networks and plays a critical role in cellular survival and growth. At 2 weeks after surgically induction of pBOO in rat, the phosphorylation (activation) level of the Akt isoform Akt1 was significantly increased in the urinary bladder, whereas the activity of Akt2 was not changed. In the urinary bladder with pBOO, excessive collagen deposition played a significant role in bladder hypertrophy, however, real‐time PCR showed that collagen mRNA level was not changed when compared to control. This was consistent to that the phosphorylation (activation) level of mammalian target of rapamycin (mTOR), p70S6 kinase (p70S6K), and 4E‐BP1, a protein synthesis pathway downstream of Akt1, were increased in pBOO bladder. The increases in protein synthesis also resulted in detrusor smooth muscle cellular hypertrophy examined by an increase in the relative level of α‐smooth muscle actin against nuclear protein histone H3. These results suggest that an increased protein synthesis regulated by Akt1‐mediated translational machinery may underlie pBOO‐induced bladder hypertrophy resulting from excessive collagen deposition and detrusor smooth muscle cellular hypertrophy.Grant Funding Source: DK077917
Iron supplementation at high altitude induces inflammation and oxidative injury to lung tissues in rats (708.7)
Authors: Salama Samir , Omar Hany , Maghrabi Ibrahim , AlSaeed Mohammed , EL‐Tarras Adel 
Published: June 2021

Iron supplementation is recommended at high altitudes to meet the demand for the high altitude‐associated physiological polycythemia. Iron is a major player in redox reactions and may exacerbate the high altitudes‐associated oxidative stress. The aim of this study was to explore the potential iron‐induced oxidative lung tissues injury in rats at high altitude. Using histopathological examination and spectrophotometry, our results showed that iron supplementation at 6000 feet altitude induced severe congestion, emphysema, and inflammatory cell infiltration to lung tissues. The levels of pro‐inflammatory cytokines (IL‐1β, IL‐6, TNF‐α), lipid peroxidation, and protein oxidation in lung tissues were significantly elevated. Antioxidant capacity of lung tissues was significantly reduced. Trolox alleviated the lung histological impairments, significantly decreased the pro‐inflammatory cytokines, and restored the oxidative stress markers. Together, our findings highlight the limitations of iron supplementation at high altitudes and suggest Trolox as a protective measure.Grant Funding Source: Supported by HARC grant number 8‐ط ‐1434 to SAS, Taif University
Effects of sub‐anesthetic sevoflurane on cardiorespiratory responses to severe arterial hypoxia in the rabbit (709.4)
Authors: O'Donnell Jonathan , Quail Anthony , Cottee David , White Saxon 
Published: June 2021

Volatile anesthetics may alter reflexes to hypoxia through actions at the carotid body chemoreceptors. The effects of sevoflurane (Sev) in sub‐anesthetic concentrations on integrated chemoreflex control during hypoxia are unknown. The cardiorespiratory responses to end‐tidal Sev (0.18%, 0.37% or 1.86%) were studied in 7 rabbits. Ventilation (VE), tidal volume (VT), respiratory rate (f), heart rate (HR) and arterial pressure (AP) were measured in awake rabbits breathing room air, then 5 minutes of hypoxia (PaO2 < 35 mm Hg), during Sev alone, and Sev plus hypoxia. In awake rabbits hypoxia produced an increase in VE and VT (p<0.05) while f was unchanged. HR fell and AP rose (p<0.05). During normoxia, VT increased and f decreased with all concentrations of Sev, while VE only fell at 0.37% and 1.86% (p<0.05). HR increased with at all concentrations while AP decreased at 0.37% and 1.86% (p<0.05). With hypoxia and Sev, the increase in VT was the same as awake levels at all concentrations associated with a small rise in f (p<0.05). VE increased to levels seen in the awake state at lower concentrations of Sev but was attenuated at 1.86% (p<0.05). The hypoxia induced bradycardia and rise in AP were attenuated by increasing doses of Sev and abolished at 1.86% (p<0.05). Sub‐anesthetic depressant effects of Sev on the cardiorespiratory responses to hypoxia are selective and therefore unlikely to be the result of carotid body inhibition.Grant Funding Source: Supported by John Hunter Hospital Charitable Trust
Upregulation of GPR50 in a white adipose depot of diet‐induced obese mice requires intact leptin signaling (711.11)
Authors: Faulkner Jessica , Gomolak Jessica , Hall John , Garrett Michael , Didion Sean 
Published: June 2021

Whole transcriptome analysis of white adipose from C57BL6 mice fed control (10% kcal) or high‐fat diet (HFD; 60% kcal) for 12 and 24 wks identified GPR50 as the most upregulated gene in response to a HFD (eg, 60‐fold in reproductive adipose at 12 wks). We tested the hypothesis that GPR50 upregulation occurs earlier than 12 wks of HFD in reproductive adipose of C57BL6 mice and in genetic models of obesity. GPR50 expression was assessed via qRT‐PCR in reproductive adipose from C57BL6 mice fed control or HFD for 1, 4, 12 and 24 wks and in db/db leptin receptor‐deficient and melanocortin 4 receptor‐deficient (MC4R‐/‐) mice. GPR50 adipose expression of 1 wk HFD mice trended higher than control (0.44‐fold±0.69, n=4; P=0.28). However, 4 wks HFD was associated with significantly higher GPR50 expression compared to control (2.77‐fold±0.73, n=4; P=0.01). qRT‐PCR confirmed GPR50 increase in adipose with 12 and 24 wks HFD compared to controls (26.4‐fold±0.73, n=4; P<0.0001 &amp; 221‐fold±2.8, n=4; P<0.0001, respectively). Adipose GPR50 expression was less in 12 wks HFD db/db mice than in HFD C57BL6 when both were compared to their control (0.61‐fold±0.13, n=2‐3). GPR50 in adipose of MC4R‐/‐ increased compared to control but not to the same degree as 24 wks HFD C57BL6 (4.9‐fold±2.1, n=4; P=0.03). These data indicate that intact leptin signaling may be required for GPR50 upregulation in white adipose of HFD‐induced obese mice.Grant Funding Source: Supported by NIH HL‐089884 and HL‐107632
Assessment of multivariate classification analysis methods on 3‐dimensional anatomical distribution of functionally identified cat pre‐Bötzinger complex microinjection sites (712.15)
Authors: Cordovez Juan , O'Neal Marvin , Solomon Irene 
Published: June 2021

Previous work from our laboratory has demonstrated that multiple patterns of phrenic motor output can be elicited by chemical stimulation of anatomically distinct sub‐regions of the in vivo adult cat pre‐Bötzinger complex. To gain further insight into the anatomical distribution of the microinjection sites yielding these different discharge patterns, we implemented two multivariate classification analysis methods: Fisher Linear Discriminant (FLD) and probabilistic neural network (PNN). For FLD analysis, the multivariate data were transformed into univariate observations by computing the inverse of a pooled variance‐covariance matrix, which was then translated back to the histological coordinates to predict physical sub‐region boundaries. For PNN analysis, a 3‐layered radial basis neural network was created with (1) the input vector for each discharge pattern yielding an output value according to how close the input vector was to each pattern weight vector, (2) the contributions for each class of inputs was summed to produce a net output vector of probabilities; and (3) a transfer function was applied to the outputs to identify the maximum probabilities and produce a classification decision. While each analysis method has its advantages (and disadvantages), both were able to predicte all of the observed phrenic discharge patterns based solely on the 3‐D coordinates of the microinjection sites. We suggest, however, that FLD analysis may be better suited for these data.Grant Funding Source: Supported by HL63175