bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disruption of Gravin's Scaffolding Protects against Isoproterenol Induced Heart Failure
Authors: McConnell Bradley , Suryavanshi Santosh , Fa'ak Faisal , Diaz Andrea Diaz , Singh Sonal 
Published: November 2023

β‐adrenergic receptor (β‐AR) signaling is the primary mechanism to increase cardiac contractility. However, chronic β‐AR stimulation, which occurs in HF, results in impairment of the β‐adrenergic pathway, leading to reduced contractility due in part by desensitization of these receptors. To induce contractility, β‐ARs signal through protein kinase A (PKA)‐dependent phosphorylation, which affects calcium homeostasis. PKA binds to A‐kinase anchoring proteins (AKAPs), which localize PKA and its substrates to defined intracellular locations. Gravin, an AKAP that targets PKA, protein kinase C (PKC) and protein phosphatase 2B (PP2B) to β2‐ARs, is involved in the modulation of the desensitization / resensitization cycle of β2‐ARs by facilitating PKA‐dependent phosphorylation and scaffolding of the β2‐AR complex. Thus, disruption of gravin's scaffolding action might prove beneficial to restore cardiac contractility during heart failure. In our studies, we used isoproterenol to chronically stimulate the β‐ARs to induce heart failure. We found that gravin‐t/t mice, harboring the truncated non‐functional gravin, leads to restriction of receptor desensitization during chronic β‐AR stimulation, due to loss in the assembly of the desensitization complex mediated by gravin's scaffolding. The β‐AR density is significantly higher in gravin‐t/t mice than wild‐type animals after 2 weeks of isoproterenol treatment. This decrease in the desensitization leads to the availability of more receptors on the heart to mediate chronotropy, ionotropy and lusitropy. Together, gravin‐t/t mice exhibited enhanced cardiac function in the presence of chronic β‐AR stimulation. PKA‐dependent substrates including cardiac troponin I (cTnI), phospholamban (PLB), and cardiac myosin binding protein C (cMyBPC), which show aberration activation patterns during heart failure, had normal phosphorylation levels in the gravin‐t/t mice, compared to the wild‐type mice. Gravin‐t/t mice also displayed enhanced myofilaments sensitivity to calcium compared to the wild‐type mice. Our results indicate that gravin plays an important role in regulating the β‐ AR pathway and disruption of its scaffolding augments cardiac function. Thus, blocking of gravin's scaffolding can be further explored as a potential therapeutic target for heart failure.Support or Funding InformationResearch reported in this poster was supported by the NHLBI institute of NIH under Award Number R01HL085487 (to B.K.M.) and R15HL124458 (to B.K.M.). This project was also supported by the Mouse Phenotyping Core at Baylor College of Medicine with funding from the NIH (U54 HG006348).
Pericyte Recruitment in a Diabetic Mouse Model of Corneal Neovascularization
Authors: Tavakol Daniel Naveed , Kelly‐Goss Molly , Yates Paul , Peirce‐Cottler Shayn 
Published: November 2023

Angiogenesis, the generation of new blood vessels from a previously existing vasculature, is reinforced by the dynamic migration and signaling of wrapping support cells, termed pericytes, covering the capillary endothelium. Understanding pericyte‐endothelial cell interactions involved in angiogenesis is essential for developing therapies targeted at improving blood vessel growth and stabilization during disease, such as in diabetic wound healing. Previous work has established a connection between diminished pericyte coverage and delayed angiogenesis in diabetic wound healing models. To date, the location and identity of pericytes in healthy versus diabetic angiogenic networks has yet to be explored. Therefore, the objective of this study is to compare the extent of pericyte coverage in angiogenic networks of diabetic versus healthy mice.Adult female heterozygous Ins2(Akita) diabetic mice and wild type mice (n=6 per group) underwent a silver nitrate chemical burn on the surface of the eye to induce corneal angiogenesis. Angiogenic sprouting into the previously avascular tissue was imaged daily using bright field microscopy. Three and seven‐days after injury, corneas were harvested and stained with CD31 (endothelial cell marker), NG2 (pericyte marker), and myosin heavy‐chain 11 (Myh11, pericyte and smooth muscle cell marker).Using whole‐mount confocal imaging, Myh11+, NG2+ perivascular coverage over CD31+ endothelial cells was quantified in the vascular areas of the mouse models. There was a negative correlation between overlapping coverage of the two pericyte markers and glucose concentration (mg/dL) at days three and seven post‐stimulation (r‐square= 0.888 and 0.893, respectively). Subconjuctival hemorrhages per tissue in diabetic models were increased by 3.64‐fold and 4.00‐fold after three and seven days between glucose level and number of hemorrhages (r‐square= 0.787 and 0.831, respectively).Diabetic neovessels in this injury model have diminished pericyte coverage relative to healthy mice, which is consistent with the presence of abundant subconjuctival hemorrhages in diabetic corneas. The comparison between data collected and glucose concentration in the blood is essential to understanding the relationship between these readings with the severity of diabetic effects, with an increase in glucose concentration equating to a decrease in pericyte‐supported vasculature. Together, these data suggest that reduced pericyte coverage on neovessels may contribute to the impaired angiogenesis that occurs during diabetic wound healing.Support or Funding InformationUniversity of Virginia Vice President for Research, Harrison Foundation, and the Arnold and Mabel Beckman Foundation
Deficiency for Smooth Muscle‐specific Insulin‐like Growth Factor I (IGF‐1) Receptor Increases Atherosclerotic Plaque Size and Promotes Plaque Destabilization
Authors: Sukhanov Sergiy , Higashi Yusuke , Snarski Patricia , Delafontaine Patrick 
Published: November 2023

We have previously shown that systemic insulin‐like growth factor I (IGF‐1) infusion reduces atherosclerosis in Apoe‐null mice. We generated smooth muscle cells (SMC)‐specific IGF‐1 receptor (IGF‐1R)/Apoe‐double‐null mice (22KI) by crossing floxed IGF‐1R mice (FIR, control) with SM22a‐promoter‐driven Cre mice to study role of SMC IGF‐1R in atherogenesis. 22KI mice had >80% reduction in aortic IGF‐1R levels, 15±3% decrease in body weight (P<0.05) and 23±3% reduction in size of individual aortic SMC (P<0.05) suggesting that marked growth retardation seen in 22KI mice was mediated by SMC hypotrophy. 22KI mice had increase in aortic atherosclerotic plaque surface area (en face analysis, 22KI: 26±5% vs. FIR: 7±4%, P<0.001) and plaque cross‐sectional area (H&E staining, 22KI: 39±5% vs. FIR: 24±3%, P<0.05). Atherosclerotic plaque in 22KI mice had significantly reduced SMC levels (aSMA IHC: 70±3% decrease; calponin IHC: 76±3% decrease vs FIR) and increased SMC apoptosis (TUNEL assay: 2.5‐fold increase, P<0.01). 22KI's plaque had marked reduction in collagen levels (Trichrome staining, 22KI: 7±2% vs. FIR: 31±4%, P<0.05) and 4‐fold decrease in levels of collagen RNA‐binding protein LARP6. Aortic SMC isolated from 22KI mice had reduced proliferation (Edu assay), suppressed cell migration (wound healing assay) and increased sensitivity to oxidant‐induced apoptosis (TUNEL assay) and these effects were associated with inhibition of IGF‐1‐induced PI3 kinase/Akt‐dependent signaling.We quantified features of former plaque disruption in brachiocephalic artery from 22KI and FIR mice. We found that 22KI's plaque has increased number of fibrous cap breaks; elevated intraplaque hemorrhage and increased fibrin deposition suggesting reduced plaque stability. In summary, SMC‐specific IGF‐1R deficiency increased atherosclerosis and reduced atherosclerotic plaque stability. Suppression of IGF‐1‐dependent and Akt‐mediated signaling may mediate pro‐atherogenic SMC phenotype in 22KI mice. These data established importance of SMC IGF‐1 signaling for atheroprotection.Support or Funding InformationNIH/NHLBI
Nrf2 deficiency exacerbates obesity‐induced neurovascular uncoupling in mice, mimicking the aging phenotype
Authors: Hertelendy Peter , Valcarcel‐Ares Marta Noa , Tarantini Stefano , Tucsek Zsuzsanna , Gautam Tripti , Farkas Eszter , Ungvari Zoltan , Csiszar Anna 
Published: November 2023

Moment‐to‐moment adjustment of cerebral blood flow (CBF) via neurovascular coupling has a critical role in maintenance of healthy cognitive function. Previous studies demonstrate that obesity promotes cognitive impairment due to, at least in part, its deleterious effects on neurovascular coupling. Importantly, the effects of obesity are exacerbated in aging, but the underlying mechanisms remain elusive. There is increasing evidence that Nrf2/ARE signaling plays a critical role in vascular resilience to obesity and the metabolic syndrome and that aging is associated with progressive Nrf2 dysfunction, promoting microvascular oxidative stress. The present study was designed to test the hypothesis that Nrf2 deficiency contributes to neurovascular uncoupling and exacerbate cerebromicrovascular dysfunction induced by obesity. To test this hypothesis Nrf2+/+ and Nrf2−/− mice were fed a standard diet or an adipogenic high fat diet (HFD) and cortical neurovascular coupling responses were assessed. In control mice feeding HFD for 6 months significantly increased vascular oxidative stress and decreased endothelium‐mediated CBF responses (laser Doppler flowmetry) in the somatosensory cortex evoked by contralateral whisker stimulation. Nrf2 deficiency significantly exacerbated HFD‐induced neurovascular uncoupling, mimicking the aging phenotype. Together, these results provide additional evidence that intact Nrf2 signaling importantly contributes to cerebromicrovascular health, preserving neurovascular coupling mechanisms. Further studies are needed to elucidate the endothelial and astrocytic mechanisms impacted by Nrf2 deficiency and HFD‐induced obesity, determining the potential roles of oxidative stress and chronic low‐grade neuroinflammation.Support or Funding InformationThis work was supported by grants from the American Heart Association and the National Institute on Aging.
Western Diet Increases Inflammatory Responses and Atherosclerosis Progression via IGF‐1 Receptor in ApoE‐Deficient Mice
Authors: Wang Meifang , Higashi Yusuke , Wang Derek , Korthuis Ronald , Delafontaine Patrice 
Published: November 2023

Atherosclerosis is the principal underlying cause of most cardiovascular disease‐related deaths, the leading cause of mortality in the US. Insulin‐like growth factor‐1 (IGF‐1) is the primary mediator of the effect of growth hormone on developmental growth which is expressed in vascular cells and monocytes/macrophages. But its role in atherosclerosis is unknown. Our previous studies show that lowered circulating IGF‐1 increases atherosclerosis progression in atherosclerosis‐prone apolipoprotein E‐deficient mice (ApoE−/−) while increased circulating IGF‐1 downregulates vascular pro‐inflammatory cytokine gene expression, reduces systemic and vascular oxidant stress, vascular cytokine expression, and decreases atherosclerosis progression. These findings led us to investigate whether the pro‐inflammatory phenotypes became more noticeable in ApoE−/− mice, in which IGF1R‐expression is deleted selectively in monocytes/macrophage (ApoE−/− LC), and whether consumption of a Western diet would change the interaction between monocytes and endothelium cells in these mice and IGF‐1R ApoE−/−‐flox mice (ApoE−/−‐FIR). To test these hypotheses, we compared baseline Monocyte Rolling (MR) and Monocyte Adhesion (MA) in both these mice fed with either normal mouse chow (NC) or Western diet (WD). There was no significant change in the pro‐inflammatory phenotype in mice with deficient IGF1R‐expression on macrophages in ApoE−/− mice. However, ingestion of a Western diet markedly increased MR and MA on ApoE−/− LC animals (ApoE−/− LC WD) compared to ApoE−/− LC NC mice, although there was no significant effect on ApoE−/−‐FIR mice. These findings indicate that the pro‐inflammatory phenotype that is enhanced by WD in ApoE−/− mice is further enhanced by specific IGF1R deficiency in monocytes/macrophages, and may consequently increase atherosclerosis progression.Support or Funding InformationR01‐HL59976, P01‐HL ‐095486 & R01‐AA22108, RO1 HL070241 and HL 080682.
N‐acetylcysteine reverses established cardiac and renal fibrosis in a mouse model of heart failure
Authors: Rajapakse Niwanthi , Giam Beverly , Chu Po‐Yin , Kiriazis Helen , Du Xiao‐Jun , Kaye David M 
Published: November 2023

BackgroundPatients with heart failure (HF) often develop secondary renal dysfunction and fibrosis plays a major pathological role in the development of both cardiac and renal dysfunction in these patients. We aimed to determine whether the antioxidant N‐acetylcysteine (NAC) can reverse cardiac and renal fibrosis in a transgenic mouse model of HF. These mice develop cardiomyopathy secondary to cardiac specific overexpression of mammalian sterile 20–like kinase 1 (MST‐1).1 Overexpression of MST‐1 in cardiomyocytes induces apoptosis1 which is relevant to human HF and we have previously demonstrated that mice with cardiac specific overexpression of MST‐1 (MST‐1 mice) develop extensive cardiac fibrosis by 13 weeks of age.2 The aim of the current study was to determine whether NAC can reverse cardiac and renal fibrosis in the setting of HF.MethodsMinipumps were implanted subcutaneously in 18 week old male wild type (WT; n=6–20) and MST‐1 mice (n=6–10) to administer NAC (40 mg/kg/day) or saline for a period of 8 weeks. At the end of this treatment period, cardiac remodelling and function was assessed via echocardiography. Fibrosis in the heart and kidney tissues was quantified using Masson Trichrome staining.ResultsCardiac perivascular and interstitial fibrosis were 2‐ and 19‐fold greater, respectively, in saline treated MST‐1 mice compared to saline treated WT (P ≤ 0.01). In NAC treated MST‐1 mice, perivascular and interstitial fibrosis were 37% and 68% less, respectively, compared to those treated with saline (P ≤ 0.05). Fractional shortening was 61% less in saline treated MST‐1 mice compared to saline treated WT. Fractional shortening was not significantly different between NAC treated MST‐1 mice and those treated with saline. Heart weight:body weight ratio was 27% greater in saline treated MST‐1 mice compared to saline treated WT (P < 0.05). This ratio was not significantly different between NAC treated MST‐1 mice and saline treated MST‐1 mice.Renal tubulointerstitial and glomerular fibrosis were 23‐ and 2‐fold greater, respectively, in saline treated MST‐1 mice compared to saline treated WT (P ≤ 0.01). Of interest, renal tubulointerstitial and glomerular fibrosis were 99% and 67% less, respectively, in NAC treated MST‐1 mice compared to those treated with saline (P ≤ 0.01).ConclusionsThese data indicate that NAC can reverse cardiac and renal fibrosis in the setting of HF potentially by reducing oxidative stress.Support or Funding InformationThis work was supported by a NHMRC (Australia) program grant.
Individual fluid therapy vs. standardized high volume fluid infusion during kidney transplantation – evaluation of oedema development, oxidative stress and inflammation levels, using a porcine model
Authors: Nielsen Lise Have 
Published: November 2023

The objective of the study is to evaluate the current fluid therapy distributed to kidney transplant patients, as to avoid overhydration.BackgroundMany kidney transplant patients are severely overhydrated after the operation, which can cause prolonged hospital stays, higher risk of infection and delayed graft function of the kidney. To avoid overhydrated patients, fluid strategies have been undergoing evaluation and validation, and it is now generally agreed that a restrictive fluid regiment is healthier. In this study we will try to access the consequences of overhydration using tissue markers of oxidative stress and inflammation in the kidney, as to quantify the risks of the above mentioned negative results.MethodsUsing a brain dead porcine model on day one, two kidneys from a single pig is taken out, stored at 4°C for 18 hours (in a cold storage solution; “Bridge of life”™/Custodiol)and then transplanted into two different pigs (after removal of the native kidneys).After reperfusion, the pigs are surveilled for 10 hours, during which blood and urine samples are collected. At the end of the experiment, the kidneys are removed and tissue samples are collected.The individual fluid therapy is 2 mL/kg/hour (with added bolus of 500 mL if the stroke volume changes more than 12% when challenged), the standardized high volume infusion is 10 mL/kg/hour, and both regimes are supplemented by bolus infusion if MAP should drop below 60 mmHg.The recipient pigs are randomly divided into 4 groups: 1) Individual Goal Directed Fluid Therapy w/o noradrenaline infusion, 2) Individual Goal Directed Fluid Therapy with noradrenaline infusion, 3) Standardized High Volume Fluid Infusion w/o noradrenaline infusion and 4) Individual Goal Directed Fluid Therapy with noradrenaline infusion.The blood, urine and tissue samples will be tested for markers of oxidative stress and inflammation; ex. glutathione, NGAL, COX‐2, TBARS.Results/discussionAs the experiment is still ongoing, no results have been obtained yet.However, every transplanted kidney has developed oedema after reperfusion, no matter what fluid treatment was given – statistics will prove whether or not the kidneys receiving standardized fluid therapy is developing more distinct oedema.We hope to discuss the effect of the infusion of low dose noradrenaline and evaluate the exact dose recommended. We would also discuss whether or not it is the difference in fluid amount that makes a difference, or rather the distribution of the fluids.ConclusionThe results are expected to influence the clinical protocol used to direct the treatment of kidney transplant patients, hereby eliminating overhydration as a delaying factor in the curative process.
Effect of db‐cAMP on Renal Interstitial Hydrostatic Pressure (RIHP) Response to Renal Medullary Direct Interstitial Volume Expansion (DIVE) in rats
Authors: Flores‐Sandoval Omar , López‐Rodríguez Juan Francisco , Sánchez‐Briones María Eugenia , Calvo‐Turrubiartes Miriam Zarahí , Rodríguez‐Martínez Manuel 
Published: November 2023

Renal medullary (rm) DIVE (100 μl infusion in 30 s) with either 0.9% saline solution (SS) or 2% albumin in SS rises slow, progressive and indistinctly the RIHP (FASEB J 27:1110.2,2013). Given the sui generis conformation and architecture of renal medullary interstitium, we assessed if dibutyryl‐cAMP (db‐cAMP, a collagen gel contraction inhibitor) modifies the time curse of RIHP response to rm DIVE with SS. Subcapsular RIHP was continuously measured in anesthetized rats with right nephrectomy, acute left renal denervation, hormonal clamp and control of renal perfusion pressure (100 mmHg) before (Pre: 30 min), during (30 s) and after (Post: 60 min) sham rm DIVE (time CTR group n = 9) and real rm DIVE with either SS (SS group, n = 8) or SS + 5mM db‐cAMP (db‐cAMP group, n = 8). There were no differences among groups in body weight, hematocrit nor plasma protein concentration at any time. The table below shows the absolute values of RIHP (mean ± SEM) before rm DIVE, in the last 10 s of rm DIVE and 20, 40 and 60 min after rm DIVE. 1WANOVA + Tukey test: ¨ P<0.05 vs. CTR group at any time point. 1WRMANOVA: · P<0.008 vs. Before. ANCOVA: there were effect of both RIHP before rm DIVE (as covariate) at any time point (P<0.001) and of group (P<0.02 in the last 10 s of rm DIVE and P<0.0001 60 min after rm DIVE). MANOVA of overall ΔRIHP (after RIHP − before RIHP) data showed time (P<0.0001), group (P<0.0023) and time * group interaction effects (P<0.0013). Continuous measurements of renal medullary blood flow (RMBF, L‐D) in two groups (SS and db‐cAMP) of an independent series showed that for the 60 min after rm DIVE the %ΔRMBF had fallen 34 ± 9 % in SS group while this variable did not change in db‐cAMP group (10 ± 9 %).CONCLUSIONSThe results suggest that db‐cAMP abolished the RIHP response to rm DIVE with SS by maintaining the baseline RMBF and/or by inhibiting the renal interstitial reactive response to rm DIVE with SS.Support or Funding InformationC13‐FAI‐03‐36.36/UASLP

Subcapsular RIHP (mmHg)

Group
Before
last 10 s
20'After
40'After
60'After

CTR
1.8 ± 0.1
1.4 ± 0.1
1.8 ± 0.3
1.9 ± 0.3
2.1 ± 0.4

SS
1.5 ± 0.2
2.4 ± 0.6
3.7 ± 0.9•
5.3 ± 1.1◆•
5.7 ± 1.2◆•

db‐cAMP
2.2 ± 0.4
2.5 ± 0.6
2.7 ± 0.5
3.0 ± 0.6♦
2.8 ± 0.5
Effect of Hypoxia on Fibroblast Proliferation in Idiopathic Pulmonary Fibrosis
Authors: Senavirathna Lakmini Kumari , Huang Chaoqun , Liu Lin 
Published: November 2023

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and usually lethal lung disease, categorized under idiopathic interstitial pneumonias. The survival rate of this disease is very low because of poor prognosis and limited effective therapies. Excess accumulation of fibroblasts, myofibroblasts and extracellular matrix proteins creates a hypoxic condition within the lungs, causing asphyxiation. Therefore, hypoxia is one of the prominent features of IPF. However, the effects of hypoxia on pulmonary fibroblasts are less studied. In this study, we evaluated the effects of hypoxia on pulmonary fibroblast proliferation and associated molecular mechanisms in vitro. Human pulmonary fibroblasts were exposed to normoxia (21% O2) and hypoxia (1% and 5% O2) for 3 and 6 days. Intracellular calcium channels, HIF 1α and HIF 2α were inhibited by specific inhibitors. Cell viability and proliferation were determined. The mRNA expression of Nuclear Factor T cell Activator (NFAT)c1, c2, c3, c4 and 5 were measured by real‐time PCR. Hypoxic conditions did not affect the cell viability. Fibroblast proliferation increased significantly at day 3 and day 6 under both hypoxic conditions compared to normoxic conditions. Calcium channel blocker and HIF 2α inhibitor inhibited hypoxia‐mediated fibroblast proliferation. Hypoxic conditions increased the mRNA expression of NFATc2 and NFATc4. In conclusion, hypoxia induces fibroblast proliferation through calcium channel, HIF 2α and NFATc2/4.Support or Funding InformationNIH R01 HL116876 and P20GM103648