bluuebunny/crossref_metadata_2025 huggingface dataset:
Amelioration of Diabetic Nephropathy Using a Retinoic Acid Receptor β2 Agonist
Authors: Trasino Steven , Tang Xiao‐Han , Shevchuk Maria M. , Choi Mary , Gudas Lorraine J
Published: June 2021

Vitamin A (VA) and its derivatives, known as retinoids, play critical roles in renal development through retinoic acid receptor β2 (RARβ2). Disruptions in VA signaling pathways are associated with the onset of diabetic nephropathy (DN). Despite the known role of RARβ2 in renal development, the effects of selective agonists for RARβ2 in a high fat diet (HFD) model of DN are unknown. Here we examined whether AC261066 (AC261), a highly selective agonist for RARβ2, exhibited therapeutic effects in a HFD model of DN in C57BL/6 mice. Twelve weeks of AC261 administration to HFD mice was well tolerated, with no observable side effects. Compared to HFD mice, HFD + AC261 treated mice had improved glycemic control and reductions in proteinuria and urine albumin to creatinine ratio. A number of molecular hallmarks of DN were mitigated in HFD + AC261 treated mice, including reductions in tubule lipid droplets (LDs), podocyte (POD) effacement, endothelial cell (EC) collapse, mesangial expansion, and glomerular basement membrane (GBM) thickening., Mesangial and tubule interstitial expression of the myofibroblast markers α‐smooth muscle actin (α‐SMA) and type IV collagen (Col‐IV) was lower in HFD + AC261 treated mice compared to HFD alone. Ultrastructural and immunohistochemistry analyses showed that, compared to HFD mice, HFD + AC261 treated mice showed preservation of POD foot process and slit diaphragm morphology, and an increase in the levels of slit‐diagram protein podocin and the transcription factor WT1 in PODs. Given the need for novel DN therapies, our results warrant further studies of the therapeutic properties of AC261 in DN.

Support or Funding Information

This research was supported in part by Weill Cornell funds and by NIH R01DK113088 to LJG. SET was supported by the National Institutes of Health (T32 CA062948)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Evaluation of Cytotoxic Effect of L‐Histidine Methyl Ester Hydrochloride of Amphotericin‐B (A21) on Tumoral Cells
Authors: Escobar‐Resendiz Rubi , Reyes‐Esparza Jorge , Ortega Ivan , Rodriguez‐Fragoso Lourdes
Published: June 2021

The term cancer encompasses a hundred diseases that are caused by damage and mutations in the genome. Damage to DNA can be caused by the increase of free radicals, which when interacting with nitrogenous bases and deoxyribose generate highly mutagenic products. The alterations in the genome trigger the activation and / or suppression of proteins that cause the cell to lose the regularization of the cell cycle and its capacity to induce apoptosis, which leads to an uncontrolled proliferation. Lung cancer is one of the leading causes of death worldwide, its main treatment is chemotherapy. Previous studies have shown that amphotericin B (AmB) has antineoplastic effects and potentiates the effect of other antineoplastics. L‐Histidyl methyl ester hydrochloride of amphotericin B (A21) is a derivative of AmB developed by researchers of the UAEM and UNAM. Preclinical studies have shown that the derivative has the same antifungal pharmacological efficacy, but less toxicity than AmB. Given that the AmB derivative is equally effective, but less toxic than the AmB, it is essential to know whether said derivative has the same antineoplastic capacity as its predecessor, and thus may be considered as an equally effective alternative treatment, but with a lower degree of toxic effects for the organism. Therefor, the aim of this work was to evaluate whether the derivative A21 produces cytotoxic effects in tumor cells.

A549 cells (ATCC CCL‐185) were used: Non‐small cell lung carcinoma cells (Human). They are grown in supplemented F‐12 Ham Kainghn's Modification medium. The cells received the following treatments: cisplatin and AmB at 3, 7, 15 and 20 μg/mL and Derivative of AmB at 3, 7, 15, 30, 60 and 120 μg/mL. The evaluation of cytotoxicity was performed by an MTT assay. Cell morphology was assessed by Giemsa staining. Subsequently, a cell proliferation assay using MTT will be performed, oxidative stress will be evaluated (ROS‐GloTM H2O2), and Caspase 8 and 9 levels will be quantified by means of a calorimetric assay.

Inhibitory concentrations 50 (IC50) of each drug were obtained in which the cell viability was 50%. The IC 50 found were: cisplatin 20.6μg/mL, AmB 60 μg/mL and derivative AmB 121 μg/mL. When evaluating the morphology of the cells, it is observed that in the treatment with cisplatin at 7μg/mL increased the size of cells. The treatment with AMB and derivative A21 at the same concentration also increased the sizes of cells with more than 1 nucleus were also observed (compared with the control). Cells treated with

The treatment with AmB and the derivative of A21 produced similar alterations in cell morphology than cisplatin. However, the IC50 were different for all treatments evaluated in A549 cells.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Role of probiotics Bifidobacterium breve and Lactobacillus rhamnosus on inflammation lung in an experimental model of chronic obstructive pulmonary disease
Authors: DE SÁ FIALHO ANA KAROLINA CARVALHO , MIRANDA MUNIQUE TOSTES FERREIRA , CARVALHO JORGE LUIS COSTA , BRITO AURILEIA APARECIDA , ALBERTINI REGIANE , AIMBIRE FLÁVIO
Published: June 2021

Introduction

Chronic pulmonary obstructive disease (COPD) is defined as an abnormal inflammatory response of the lungs to noxious particles or gases, mainly cigarette smoke. Thus, new therapeutic approaches are of unquestionable relevance. Without a specific treatment for COPD patients the use of probiotics via supplementation of diet can be a promising target. This project aims to investigate the beneficial effects of Bifidobacterium breve (Bb) and Lactobacillus rhamnosus (Lr) probiotics in lung inflammatory process in mice in a model of lung emphysema.

Methods

This study was approved by the Ethics Committee of the UNIFESP. The COPD was induced by cigarette smoke inhalation of 14 cigarette per day, twice a day, 7 times/week during 60 days in C57Bl/6 mice. The mice were treated with Lr and Bb at the same time. The pro‐inflammatory mediators as IL‐6, TNF, IL‐1 β, CXCL1, CXCL8, CXCL10, KC, CXCL9, CXCL11 and anti‐inflammatory as IL‐10 in bronchoalveolar lavage fluid (BALF) were measured by ELISA. The expression of mRNA of the MMP9 and MMP12, NF‐κB, STAT3 and TLR 2,4 and 9 in lung were analyzed by quantitative RT‐PCR. The NF‐κB was also analyzed by immunolocalization. The lung tissue was used for histological and morphometric analyzes.

Results

Bb and Lr attenuated the cellularity in BALF and reduced the pro‐inflammatory cytokines and inversely increased the anti‐inflammatory. Also, the probiotics reduced the expression of MMP9 and 12, NF‐κB, STAT3 and TLR 2,4 and 9 in lung. Then, the probiotic also changed the airway remodeling (inflammatory infiltrate, alveolar enlargement, collagen, and elastic fibers).

Conclusion

This study points out that the probiotics decreased the cellularity on the BALF and the expression of the main transcription factors as a consequence they also reduced pro‐inflammatory cytokines and inversely increase anti‐inflammatory. These results contribute to the understanding of Bb and Lr modulator activities.

Support or Funding Information

Financial Support: Foundation for Research Support of the State of São Paulo (FAPESP)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Probiotics Improve Flora Alternation and Memory Deficits in Aged Mice
Authors: Du Junrong , Yang Xueqin , Yu Dongke , Xue Li
Published: June 2021

Probiotics, multi‐species live microorganisms, can delay the progression of some neurodegenerative diseases. However, the effects of probiotics on the gut‐brain axis remain unclear, particularly in the context of aging and neurodegenerative diseases. The senescence‐accelerated mouse prone 8 (SAMP8) mouse strain is used as an aging model. To investigate the effects of probiotics, 9‐month‐old male SAMP8 mice were treated with probiotics (four species of Lactobacillus and Bifidobacterium) for 12 weeks. The results demonstrated that probiotics treatment significantly reduced memory deficits, neuronal loss and synaptophysin. 16S RNA analysis revealed that the microbiome composition in the brain and feces was modified by probiotic treatment. In addition, probiotic treatment reduced aging‐induced intestinal barrier and blood‐brain barrier injury. Probiotic treatment also significantly reduced lipopolysaccharide concentrations both in the brain and plasma. Probiotics significantly decreased the immunoreactivity of ionized calcium binding adaptor molecule‐1 and glial fibrillary acidic protein, the expression of Toll‐like receptor 4, the nuclear translocation of nuclear factor‐κB, and mRNA expression of proinflammatory cytokines (tumor necrosis factor‐α and interleukin‐6) in the brain. These findings indicate that the cognitive‐enhancing effects of probiotics in aged SAMP8 mice may be modulated by the gut‐brain axis and the inhibition of inflammation via the LPS‐TLR4/NF‐κB signaling pathway.

Support or Funding Information

This work was supported partly by Sichuan University ‐ Luzhou Project (2016CDLZ‐S16), targeting drug delivery system of Sichuan Province Youth Science and Technology Innovation Team (2016TD0001) and 111 Project of the National Ministry of Education (B18035).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Butyric Acid, a Gut Bacteria‐Produced Metabolite, Decreases Arterial Blood Pressure via a Gut‐Vagus Nerve Signaling in Rats
Authors: Ufnal Marcin , Onyszkiewicz Maksymilian , Gawrys Marta , Huc Tomasz , Aleksandrowicz Marta , Sawicka Aneta , Kozniewska Ewa , Samborowska Emilia
Published: June 2021

Butyric acid (BA) is one of several short‐chain fatty acids (SCFAs) produced by gut microbiota. The aim of the study was to evaluate if BA may exert hemodynamic effects via an afferent gut‐nervous system signalling. Hemodynamics were recorded in male, 14‐week‐old, anesthetized, Wistar rats. A vehicle (0.9% NaCl), BA, or 3‐hydroxybutyrate, an antagonist of SCFA receptors GPR41/43 (ANT) were administered into the colon (IC) or intravenously (IV). Reactivity of mesenteric (MA) and gracilis muscle (GMA) arteries was tested in vitro. SCFAs concentration was measured using ultra performance liquid chromatograph with mass spectrometer. Physiological BA concentration in the colon content (stools) was ≈ 9mM but 1000‐fold lower in systemic venous blood. The vehicle and ANT did not affect arterial blood pressure (BP) and heart rate (HR). BA administered IC produced 2–3‐fold increase in BA colon content and a prolonged decrease in BP and HR, with no significant changes in QTc, a marker of cardiotoxicity. Intestinal blood flow was not affected. Subphrenic vagotomy and IC pretreatment with ANT significantly reduced the hypotensive effect of IC BA. The hypotensive effect was also reduced by IV administered hexamethonium but not by atropine. BA administered IV produced shorter decrease in BP than BA administered IC, and did not affect HR. The ANT reduced, whereas L‐NAME, a nitric oxide synthase inhibitor, did not affect the hypotensive effect of IV BA. In vitro, BA dilated MA and GMA at concentrations 10–20‐fold higher than physiological concentration of BA in systemic blood. In conclusion, at physiological concentration the colon appears the most likely site of BA action. An increase in colonic BA lowers BP. This seems to be mediated by vagal signaling and GPR41/43.

Support or Funding Information

Supported by the National Science Centre, Poland grant no. UMO‐2016/22/E/NZ5/00647

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Neovascularization and functional assessment of human pancreatic islets encapsulated with immuno‐modulatory stem cells
Authors: Azimi Mohammad Sadegh , He Yi , Wang Yong , Peirce‐Cottler Shayn , Pollok Brian
Published: June 2021

Background & Objective

Developing successful therapies based on re‐introduction of healthy pancreatic islets in diabetic patients requires new strategies to combat the immune response caused by implantation, as well as improving neovascularization and engraftment of the implant. Human amniotic epithelial cells (AECs) are immuno‐modulatory stem cells that can confer a local immune‐privileged environment in vivo, and block grafted tissue rejection [1]. The objective of this study was to develop a protocol for encapsulating islets with AECs, and examine the effects of encapsulation on islet function, and neovascularization.

Methods

Human pancreatic islets were individually placed in ultra‐low attachment round bottom wells with human islet medium, and were divided into three experimental groups: 1) islet‐only, 2) adipose‐derived stem cells (ASCs)+islet, and 3) AECs+islet. For groups 2 and 3, each islet was assumed to have ~2000 beta cells, and the stem cells were added to each well to encapsulate individual islets at 2:1 cell ratio. The temporal c‐peptide secretion level was measured after 3 and 6 days by perfusing the islets with basal and high glucose solutions using dynamic readout assay, and confirmed the functionality of the encapsulated islets. To assess the angiogenic properties of encapsulation, cell culture supernates were collected after 6 days of culture, and used for an angiogenesis array kit, to identify and compare the level of 52 angiogenic factors present in each group. The same test was repeated for ASC‐ and AEC‐only cultures to identify any effects caused by the cell encapsulation.

Results & Conclusions

The level of pro‐angiogenic factors increased in encapsulated groups compared to the islet‐only group (Fig. 1). A larger increase in angiogenic factors in encapsulated islets compared to stem cell‐only groups demonstrated a synergetic angiogenic effect caused by encapsulation of islets with ASCs and AECs. To test the angiogenic response in a physiological scenario, the islets were seeded on rat mesentery tissues, and cultured for 6 days, and the level of angiogenic response was compared between different groups. Our results highlight the effect of encapsulating human islets with ASCs and AECs on engraftment and neovascularization, and showcase the potential of the islet cell encapsulation method for a successful long‐term implantation in patients with diabetes.

Support or Funding Information

The Virginia Catalyst and UVA Center for Advanced Biomanufacturing

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Interaction of obesity and Nrf2 deficiency exacerbates vascular aging: potential role of endothelial senescence
Authors: Balasubramanian Priya , Kiss Tamas , Tarantini Stefano , Yabluchanskiy Andriy , Csipo Tamas , Lipecz Agnes , Farkas Eszter , Ungvari Zoltan , Csiszar Anna
Published: June 2021

Previous studies demonstrate that obesity promotes cognitive impairment due to, at least in part, its deleterious effects on the cerebral microvasculature. Importantly, the effects of obesity are exacerbated in aging, but the underlying mechanisms remain elusive. Nuclear factor erythroid 2‐related factor (Nrf2) is a master transcriptional factor that regulates the expression of anti‐oxidant and anti‐inflammatory genes. 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 vascular oxidative stress. The present study was designed to test the hypothesis that Nrf2 deficiency exacerbates endothelial senescence and cerebromicrovascular dysfunction induced by obesity. To test this hypothesis, we developed a transgenic animal model to investigate senescence induced by Nrf2 deficiency by crossing Nrf2 knock out mice (Nrf2−/−) with a senescence reporter mice. In the senescence reporter mice, p16‐positive senescent cells can be detected in tissues by red fluorescent protein (mRFP) expression. Nrf2+/+ and Nrf2−/− senescence reporter mice were fed a standard diet or an adipogenic high fat diet (HFD) for 5 months. At the end of the dietary treatment, blood‐brain barrier (BBB) integrity was assessed by the permeability of the fluorescent tracer, Cadaverine Alexa‐fluor‐555 (Cad‐555) into the brain parenchyma. Endothelium‐dependent increases in cerebral blood flow (CBF) in response to contralateral whisker stimulation were measured by laser speckle contrast imaging. Finally, we assessed senescence in the hippocampus and cortex by quantifying mRFP positive endothelial cells and through gene expression analysis related to senescence pathways. HFD treatment in Nrf2+/+ mice for 6 months significantly increased the accumulation of Cad‐555 in the brain parenchyma, suggesting impaired BBB integrity. In addition, HFD treatment impaired endothelial function and significantly increased the expression of senescence related genes and number of RFP positive cells in the hippocampus of Nrf2+/+ animals. Nrf2 deficiency significantly exacerbated HFD‐induced BBB damage, endothelial senescence and worsened endothelial dysfunction, mimicking the aging phenotype. Together, these results provide additional evidence that intact Nrf2 signaling importantly contributes to cerebromicrovascular health, protecting against endothelial senescence and preserving endothelium‐dependent regulation of blood flow.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Targeting Plasminogen Activator Inhibitor‐1 Alleviates Inflammatory Responses Invoked by Sepsis or Chlorinated Lipid
Authors: Yu Hong , Wang Meifang , Wang Derek Z. , Kalogeris Theodore J. , Restrepo Ricardo J. , Fay William P. , Ford David A. , Korthuis Ronald J.
Published: June 2021

Plasminogen activator inhibitor‐1 (PAI‐1) promotes leukocyte‐endothelium interactions and transmigration secondary to ischemia/reperfusion (I/R). Our previous work demonstrated that 2‐chlorohexadecanal (2‐ClHDA), derived from myeloperoxidase (MPO) produced hypochlorous acid (HOCL) targeting of plasmalogen phospholipids, may serve as a mediator of the inflammatory responses to sepsis. Given the fact that the septic inflammatory responses invoked by cecal ligation and puncture (CLP) can be reversed by an MPO inhibitor, we have postulated that sepsis‐induced inflammation may be mediated through MPO/HOCL/2‐ClHDA axis. However, the utility of drug targeting of PAI‐1 to inhibit inflammatory responses induced by CLP or 2‐ClHDA superfusion remains to be evaluated. We have begun to explore this issue by pretreating rats with PAI‐1 inhibitor, PAI‐039 (tiplaxtinin, 44 ug/kg) one hour prior to CLP or Sham surgery and then again one hour before beginning to take measurements. Six hours after surgery, inflammatory responses in four groups of Sprague‐Dawley rats (n=6) were quantified and compared on leukocyte‐endothelial cell interactions and mast cell degranulation in rat mesenteries using intravital microscopy. In other groups of rats pretreated with PAI‐039 one hour beforehand, the exposed mesenteries were superfused with 2‐ClHDA at 10 mM (a dose within the range of plasma concentrations reported for septic patients or rats) for ninety minutes, with inflammatory responses recorded at baseline, thirty, sixty and ninety minutes. The data showed that CLP or mesenteric superfusion with 2‐ClHDA induced marked increases in the numbers of rolling and firmly adherent leukocytes, and significant mast cell activation that were similar in magnitude in both models, and were prevented by pretreatment with the PAI‐1 inhibitor PAI‐039. Our results indicate that the increases in leukocyte rolling, leukocyte adhesion, and mast cell degranulation invoked by 2‐ClHDA superfusion mimicked the responses to CLP. Moreover, these proinflammatory responses appear to be dependent on PAI‐1.

Support or Funding Information

Supported by NIH grant GM‐115553.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Vascular Dysfunction in Chronic Obstructive Pulmonary Disease (COPD): The Role of Mitochondrial‐derived Oxidative Stress
Authors: Kwon Oh Sung , Layec Gwenael , Broxterman Ryan M , Gifford Jayson R , Park Soung Hun , Shields Katherine L , Richardson Russell S
Published: June 2021

Background

This study sought to determine the contribution of mitochondrial‐derived oxidative stress in the vascular dysfunction exhibited by patients with COPD.

Methods

Vascular function was assessed with brachial artery flow‐mediated vasodilation (FMD) and the hyperemic response to both single and continuous passive leg movement (PLM) in 10 patients with COPD (55–70 years) before and after both the acute and chronic ingestion (4 weeks) of a mitochondrial‐targeted antioxidant (MitoQ) (20mg/day).

Results

Baseline % FMD (2.5 ± 0.9 %) in the patients with COPD was significantly enhanced by both the acute (3.3 ± 0.8 %) and 4 week (5.3 ± 1.2 %) MitoQ consumption. Acute MitoQ had no effect on the single PLM‐induced change in peak LBF (ΔPeak) or the area under the leg blood flow (LBF) response curve (AUC), but the 4 week MitoQ consumption significantly augmented both the single PLM ΔPeak (190±184 vs. 300±96 ml/min) and LBF AUC (20±14 vs. 50±16 ml). Compared to baseline (ΔPeak = 300±84 ml/min; LBF AUC = 80±34 ml), both ΔPeak and LBF AUC during continuous PLM‐were significantly enhanced with both the acute (ΔPeak: 435±96 ml/min; LBF AUC: 105±56 ml) and 4 week (ΔPeak: 622±106 ml/min; LBF AUC: 300±120 ml) MitoQ consumption.

Conclusions

This study reveals that, in patients with COPD, mitochondrial‐derived oxidative stress contributes significantly to the vascular dysfunction exhibited by this population. Therefore, targeting mitochondrial‐derived oxidative stress may, through an improvement in vascular function, be an efficacious approach to combat cardiovascular disease in patients with COPD.

Support or Funding Information

This work was funded, in part, by the National Heart, Lung, and Blood Institute at the National Institute of Health (PO1 HL1091830, K99HL 125756 and T32 HL139451), the Flight Attendant Medical Research Institute (FAMRI), and the Veteran's Administration Rehabilitation Research and Development Service (E6910‐R, E1697‐R, E1433‐P, E9275‐L and E1572‐P).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Xanthine Oxidase Mediates Cerebrovascular Function Impairment in Chronically Stressed Mice
Authors: Burrage Emily Nicole , Marshall Kent L. , Parsley Matthew C. , Tice Abigail L. , Aboaziza Eiman A. , Clay Allison , Frisbee Jefferson C , Kelley Eric E. , Chantler Paul D
Published: June 2021

Chronic stress‐induced depression is a major cerebrovascular risk factor, and the link between obesity and depression is strong. We have previously shown that chronic stress in obese rats significantly reduces cerebrovascular function, mediated by an increase in oxidative stress. Xanthine oxidase (XO) is a major source of oxidative stress, thus, we examined the effects of Febuxostat (XO inhibitor) on improving cerebrovascular function after the development of depressive like symptoms.

Diet induced obesity (60 kcal% fat) started at 6 weeks of age in C57BL/6 mice (n=12) lasting for a total of twenty weeks. During the final eight weeks, 6 mice underwent the unpredictable chronic mild stress (UCMS; 5 days/week for 7 Hrs/day) model to elicit a depressive phenotype. On week twenty, the mice were euthanized and the middle cerebral arteries (MCA) were removed and positioned in a pressurize myobath. To test for vessel health, the MCA was exposed it to increasing concentrations of acetylcholine (Ach; 10−9M to 10−4M) in the presence or absence of Febuxostat (40μM), XO (40μM), and L‐NAME (10−4M).

MCA dilation to Ach was impaired in obese mice that underwent UCMS compared to obese control mice (7±1% vs. 23±3%, p<0.05). Incubating the MCA with Febuxostat for 30 minutes in the chamber did not improve MCA dilation to Ach in the obese control mice but restored MCA dilation in the UCMS obese mice (26±2% vs. 25±3%, p<0.05, respectively). Incubating the MCA with XO or L‐NAME had the same affect and reduced MCA dilation to Ach to 6% and 5%, respectively, in the obese control mice. Further, in the UCMS obese mice, max Ach dilation did not differ to the Ach dilation in the presence of L‐NAME. These data suggest that a depressive phenotype generates an increased production of reactive oxygen species possibly via increased activity of xanthine oxidase.

Support or Funding Information

NIH Cobra Grant 5P20GM109098

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Dynamic cerebral carbon dioxide reactivity at rest and during exercise
Authors: Ogoh Shigehiko , Shigeki Shibata , Nakahara Hidehiro , Miyamoto Tadayoshi
Published: June 2021

The cerebral vasculature is highly sensitive to direct arterial carbon dioxide tension (PaCO2) changes. Hypocapnia causes cerebral vasoconstriction, while hypercapnia causes cerebral vasodilation to maintain the brain tissue PCO2 within narrow limits. The cerebral blood flow (CBF) responses to PaCO2 changes should be quick, but the cerebral vasculature sensitivity as cerebral CO2 is measured during steady‐state vascular responses. Therefore, the CBF time response to PaCO2 changes remains unknown. The purpose of this study was to examine dynamic cerebral CO2 reactivity at rest and during exercise using the frequency domain analysis.

Seven healthy young subjects participated in the study. At rest and during exercise (30% VO2max and cycling exercise), the dynamic CO2 reactivity was calculated based on the transfer function analysis between the end‐tidal CO2 (PETCO2) and the middle cerebral artery mean blood velocity (MCAvm), using a binary white‐noise sequence (0%–7% inspired CO2 fraction). Dynamic characteristics of the respiratory controller showed a low‐pass filter characteristic for regulating ventilation, and the dynamic gain was decreased gradually to 0.7 at 0.02 Hz. However, the gain from PETCO2 to MCAvm (dynamic CO2 reactivity) remained reasonably constant up to 0.02 Hz. Moreover, it did not change during exercise.

These findings suggest that the dynamic cerebral CO2 reactivity is reflected in slow to fast PaCO2 changes, and does not change during exercise. In terms of CO2 homeostasis, the cerebral CO2 reactivity may be a more important physiological mechanism to adapt to fast CO2 changes than the ventilatory response to PaCO2 changes.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Examination of hemodynamic environments of carotid stenosis with computational fluid dynamics
Authors: Fukuda Shunichi , Shimogonya Yuji
Published: June 2021

Introduction

Carotid arterial geometry is an independent risk factor for carotid stenosis, in which hemodynamics, classically low oscillatory shear stress, is thought to be involved. However, there are few reports indicating quantitative analyses of hemodynamic environments in carotid stenosis. Thus, we are conducting a prospective clinical study with computational fluid dynamic techniques, and 454 cases of carotid stenosis have been registered to date. Here, we focused on unilateral stenotic cases among them and compared hemodynamic distributions between stenotic and non‐stenotic sides. We also examined hemodynamic distributions of carotid arteries after releasing stenosis by carotid endarterectomy.

Methods

Hemodynamic distributions were examined using ANSYS‐CFX software. Patient‐specific arterial geometries and inflow velocities were obtained from 3‐dimensional computed tomographic angiography and carotid ultrasound Doppler examinations, respectively.

Results

In both the stenotic area and the area proximal to the stenotic area, hemodynamic metrics indicating the magnitude of time‐averaged wall shear stress (TAWSS) were significantly higher compared with the non‐stenotic side (p=0.0027 and 0.0007, rspectively), whereas WSS disturbance‐based metrics, i.e. oscillating shear index (OSI, p=0.0006 and 0.0008) and normalized transverse WSS (NtransWSS, p<0.0001 and p=0.0029), were rather lower. However, in the region distal to the stenotic area, OSI (p=0.0009) and NtransWSS (p=0.0021), but not TAWSS (p=0.4564), were significantly higher as compared with the same area of non‐stenotic side (Figure). WSS gradient on carotid bulb after carotid endarterectomy was significantly higher compared with controls (p=0.037), suggesting that the carotid arteries may primarily have geometric risks for stronger hemodynamic stress.

Conclusions

The results suggested that hemodynamic environments in carotid stenosis are more complex than previously thought. High WSS in the stenotic area and enhanced WSS disturbance downstream of the stenotic area may be associated with progression of stenosis and plaque rupture.

Support or Funding Information

This study is supported by the Grant‐in‐Aid for the Japanese National Hospital Organization Multi‐Center Clinical Research, AMED under Grant Number JP15gm0810006h0301, and JSPS KAKENHI Grant Number 15K10323.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A novel role for the transplantation of adipose tissue in ischemia‐neovasculature
Authors: Wu Jianbo , Li Rong , Chen Liyuan , Wang Lin
Published: June 2021

Background

Fat deposition is associated with peripheral arterial disease. Adipose tissue has recently been implicated in vascular remodeling and angiogenic activity.

We hypothesized that the transplantation of adipose tissues from normal mice improves blood flow perfusion and neovascularization in high‐fat diet fed mice.

Methods

After 14 weeks of high‐fat diet (HFD)‐fed mice, unilateral hind limb ischemia was performed. Subcutaneous white adipose tissue (WAT) and brown adipose tissue (BAT) fat pads were harvested from normal EGFP mice, and subcutaneously transplanted over the region of the adductor muscles of HFD mice. Blood flow was measured using Laser Doppler Scanner. Vascular density, macrophages infiltration, and macrophage polarization were examined by RT‐qPCR, and immunohistochemistry.

Results

We found that the transplantation of WAT derived from normal mice improved functional blood flow in HFD‐fed mice compared to mice transplanted with BAT and sham‐treated mice. WAT transplantation increased the recruitment of pericytes associated with nascent blood vessels, but did not affect capillary formation. Furthermore, transplantation of WAT prevented HFD‐induced insulin resistance, M2 macrophage predominance and the release of arteriogenic factors in ischemic muscles. Mice receiving WAT also displayed a marked reduction in several proinflammatory cytokines. In contrast, mice transplanted with BAT were glucose intolerant and demonstrated increased IL‐6 levels in ischemic muscles.

Conclusion

These results indicate that transplantation of adipose tissue elicits improvements in blood perfusion and beneficial effects on systemic glucose homeostasis and could be a promising therapeutic option for the treatment of diabetic peripheral arterial disease.

Support or Funding Information

This work was supported by the National Natural Science Foundation of China Grant (81172050, 81570263, and 81402431), Grant of Sichuan Province Science and Technology Agency Grant (2014FZ0104).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Extracellular matrix components isolated from diabetic mice alters cardiac fibroblast function through the AGE/RAGE signaling cascade
Authors: Burr Stephanie , Stewart James A
Published: June 2021

Roughly 30 million Americans suffer from diabetes and these individuals are at an increased risk of developing cardiovascular complications. The most common type of cardiovascular complication is heart failure, where the heart is unable to adequately pump blood throughout the body. Heart failure can be a result of the stiffening of the left ventricle which occurs when cardiac fibroblasts become “active” and begin to remodel the extracellular matrix (ECM). Fibroblast “activation” can be triggered by the AGE/RAGE signaling cascade. Advanced Glycated End products (AGEs) are produced and accumulate in the ECM overtime in a healthy individual, but under hyperglycemic conditions, this process is accelerated. We aim to investigate how the presence of AGEs in the either diabetic or non‐diabetic ECM can affect fibroblast ECM remodeling as well as determine the role of AGE/RAGE signaling during this process. In order to assess this question diabetic and non‐diabetic fibroblasts were embedded in 3D matrices composed of collagen isolated from either diabetic or non‐diabetic mice. Fibroblast function was assessed using gel contraction, migration, proliferation, and protein expression. The role of AGE/RAGE signaling during the 3D matrix experiment was determined by either activating the signaling pathway using AGE‐BSA or inhibiting specific signaling components through drug treatments. Non‐diabetic fibroblasts displayed similar gel contraction to diabetic cells when embedded in diabetic collagen. Thus, suggesting the diabetic ECM can alter fibroblast function from “inactive” to “active” states. In addition, increasing the AGE/RAGE cascade leads to increase gel contraction whereas inhibiting the cascade leads to little or no gel contraction. These results indicate 1) the ECM from diabetic and non‐diabetic mice differ from one another, 2) diabetic ECM can impact fibroblast function and shift them towards an “active” state, and 3) that fibroblasts can modify the ECM through activation of the AGE/RAGE signaling cascade. These results suggest the importance of understanding the impact diabetes has on the ECM and fibroblast function, more specially how these two components are intertwined with one another. Unraveling this issue will provide better insight into the impact of diabetic and cardiovascular complications.

Support or Funding Information

US Army Medical Research Award #81XWH‐16‐1‐0710

University of Mississippi School of Pharmacy; Department of BioMolecular Sciences

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Safety of Continuous Postextrasystolic Pacing in the Human
Authors: Stein Paul M.
Published: June 2021

Continuous postextrasystolic pacing is a potential positive inotropic treatment for several depressed myocardial states. The safety of this pacing, however, has been questioned since the mid‐1960's because the pacing markedly raises the myocardial oxygen consumption, thereby increasing the potential for proarrhythmia. To understand the actual safety of continuous postextrasystolic pacing, six clinical studies and case reports were reviewed involving a wide range of cardiovascular maladies (atrial or ventricular septal defect, congestive cardiomyopathy, heart failure, mitral or pulmonary stenosis, mitral, tricuspid, or aortic regurgitation, patent ductus arteriosis, mitral valve prolapse, coronary arterial‐arteriosclerotic heart disease, and pulmonary arterial hypertension):

Braunwald E., et al. Amer. J. Med. 37: 700–711, 1964.

Meijler, F. L. and D. Durrer. Bull. N. Y. Acad. Med. 41: 575–591, 1965.

Lister, J. W., et al. Am. Heart J. 73: 362–368, 1967.

Resnekov, L. Med. Clin. N. Amer. 54: 247–259, 1970.

Gerschwind, H., et al. J. Am. Coll. Cardiol. 4: 216–225, 1984.

Freudenberger, R., et al. J. Cardiac Fail. 14: 35–40, 2008.

Patients received paired or coupled atrial, ventricular, or dual‐chamber pacing. Continuous postextrasystolic pacing in 63 of 63 patients resulted in zero incidences of ventricular tachyarrhythmia induction, including in 7 with a compromised coronary circulation. Only when a seventh clinical study was reviewed, involving myocardial infarction‐associated cardiogenic shock, did any arrhythmia occur, and only in 1 of 5 cases:

Gourgon, R., et al. Paired Pulse Stimulation of the Heart. Proceedings of the Second Conference on Paired Pulse Stimulation and Postextrasystolic Potentiation in the Heart. 1968. pp. 36–51.

Hence, when coronary arterial blood flow and myocardial oxygen supply are not compromised, and in the vast majority of cases where it is, continuous postextrasystolic potentiation pacing is a safe positive inotropic technique.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Arginase exhibits negative regulation of respiration in isolated murine cardiac mitochondria independent of mitochondrial nitric oxide synthase
Authors: Mahalingam Padmini , Sakamuri Siva S. V. P. , Sperling Jared A. , Sure Venkata N. , Katakam Prasad V. G.
Published: June 2021

Objective

Mitochondrial dysfunction underlies the development of various cardiovascular diseases. Previously, we reported the presence of mitochondrial nitric oxide synthase (mtNOS) in cardiomyocytes and for the first time observed that NOS inhibitors decreased the state IIIu respiration in isolated cardiac mitochondria but had no significant effect on basal/state II or ATP production. These effects of NOS inhibitors on mitochondrial respiration in isolated mitochondria were significantly different than the effects on mitochondrial respiration in intact cells suggesting novel functional role of mtNOS. Arginase regulates the levels of arginine available for the local nitric oxide synthases, thereby regulating the NO production. Cardiomyocytes specifically express arginase II localized in mitochondria and has been shown to regulate cardiomyocyte contractility. We hypothesized that inhibition of arginase II increases respiration in isolated murine cardiac mitochondria in vitro.

Methods

Cardiac mitochondria were isolated from three‐month‐old C57bl6 (n= 4–5) mice and treated with specific arginase inhibitor, S‐(2‐boronoethyl)‐L‐cysteine hydrochloride, S‐(2‐boronoethyl)‐L‐cysteine, BEC (100μM) for 30 minutes in assay buffer containing 10 mM pyruvate and 2 mM malate. Mitochondria (5 μg/well) were plated into cell plates and oxygen consumption rate (OCR) was measured using Agilent Seahorse XFe24 analyzer after serial injections of ADP (5 mM), oligomycin (5 μM), FCCP (5 μM) and antimycin and rotenone (10 μM and 2 μM). Respiratory parameters were reported as OCR (pico moles of oxygen/minute).

Results

Arginase inhibition did not significantly alter the basal/state II respiration (106.2 ± 6.2 vs 98.8 ± 1.6) or state IVo (87.1 ± 8.0 vs 80.9 ± 7.7) or proton leak (53.2 ± 11.6 vs 41.7 ± 5.7). Interestingly, arginase inhibition increased the ADP‐induced or state III respiration by 25% (329.9 ± 18.7 vs 263.5 ± 20.2, p=0.05) and ATP production by 30% (237.5 ± 13.5 vs 182.7 ± 15.5, p=0.03) compared to untreated mitochondria. Uncoupler‐induced or state IIIu respiration (state IIIu) showed strong trend towards increase by 33% (237.5 ± 13.6 vs 182.7 ± 15.5, p=0.059) in isolated mitochondria treated with arginase inhibitor.

Conclusions

Arginase II negatively regulates the mitochondrial respiration in the heart and thus along with mtNOS it may play critical role in cardiovascular physiology and pathophysiology.

Support or Funding Information

Support: National Institute of Health: National Institute of General Medical Sciences and National Institute of Neurological Disorders and Stroke (Katakam: R01NS094834).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Estrogen mitigates leptin's effect on blood pressure through the SOCS3 signaling cascade
Authors: Kaul Sakshi , Halaharvi Harikrishna , Barnes Maria J
Published: June 2021

Estrogen has been purported to play a protective role against high blood pressure ‐ a possible explanation for the reduced prevalence of hypertension among pre‐menopausal women as compared to aged‐matched men. The loss of endogenous estrogen during menopause is correlated with a striking increase in the incidence of hypertension in women ‐ a leading risk factor of heart failure, stroke, and kidney disease. Thus, it is imperative to identify how estrogen attenuates hypertension. Our studies have demonstrated that leptin plays a significant role in augmenting blood pressure in the absence of estrogen. Bilateral ovariectomized (OVX) female rats were used to investigate the hypothesis that estrogen can mitigate leptin‐induced hypertension by increasing the expression of Suppressor of Cytokine Signaling 3 (SOCS3). SOCS3 is an inhibitor of the JAK/STAT signaling, a key pathway through which leptin increases blood pressure. OVX and control animals either received a sole intracerebroventricular injections of saline, leptin or estrogen, or a combination of saline/leptin or estrogen/leptin. Thirty minutes later, the hypothalami of animals that received a single injection were extracted and prepared for western blot analysis. Brains of the animals from the dual‐injection group were perfused and extracted for immunohistochemistry. Western blot analysis demonstrated that estrogen increases the expression of hypothalamic SOCS3 in the OVX group. Histological staining demonstrated that pretreatment with estrogen attenuated neuronal activation by leptin. Taken together, these data suggest that estrogen can attenuate leptin's effect on blood pressure by increasing the expression of SOCS3.

Support or Funding Information

Supported by The Iowa Osteopathic Educational Research Foundation

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Differences in Exercise‐Induced Blood Flow Patterns between Apparently Healthy Female and Male Subjects
Authors: Pena Marcelo , Pena Francisco J , Rodriguez Lisa , Morales‐Acuna Francisco J , Gurovich Alvaro N
Published: June 2021

Studies suggest that aerobic exercise (AX) induced endothelial shear stress (ESS) may be a preventive measure for atherosclerosis. However, ESS can be different based on blood flow patterns and between males and females. Therefore, the aims of the present study were to identify changes in blood flow patterns in relation to aerobic exercise (AX) intensity and identify if blood flow patterns are different between females and males. To accomplish these aims 17 young healthy subjects (9 females and 9 males) between the ages of 18–35 were recruited to perform two AX tests on a stationary bicycle. The First test was a graded exercise test (GXT) and was used to determine the exercise intensities for the second test via blood lactate (BL) levels. The second test was performed 48–72 hours later and consisted of three stages of steady‐state AX intensities based in BL (low: <2 mmol/L; medium: 2–4 mmol/L; and high: >4 mmol/L). During both test, artery diameter and blood flow patterns (i.e.: ESS, direction, and presence of turbulence) in the subject's brachial artery was recorded using Doppler and high definition ultrasound. Afterwards, exercise induced endothelial shear stress and presence of turbulence were calculated using Womersley's approximation and Reynolds number (Re) calculation, respectively. Blood flow pattern was mainly antegrade in both males and females. ESS (dynes/cm2) and Re were intensity depended in both males and females. In addition, ESS and Re were similar between sexes at baseline, low, moderate, and high workloads. Interestingly, brachial artery diameter (mm) did not change with exercise intensity in both males and females; however, baseline diameter was smaller in females than males (Table).

Blood Flow patterns between females and males are very similar. Intensity dependency for ESS and Re is seeing in both males and females. However, this study showed that there was a significant difference in arterial diameter only at baseline and that artery diameters do not change with exercise intensity. Interestingly, there was a trend for smaller artery diameters across all exercise intensities in females, which might help increasing ESS to compensate for lower systolic blood pressure.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Influence of Creatine Supplementation and High Intensity Interval Training on Glycemic Profile and Cardiac Morphology in Rats
Authors: Martinez Paula F , Morais Camila S , Ota Gabriel E , Carvalho Marianna R , Gomes Mariana J , Cruz Arthur DFC , Oliveira Jéssica ML , Oliveira Paola CS , Mendonça Maria LM , Okoshi Katashi , Okoshi Marina P , Oliveira‐Junior Silvio A
Published: June 2021

Background

Creatine supplementation may induce insulin resistance, a condition associated with cardiac remodeling and also a risk factor for cardiovascular disease. High intensity interval training (HITT) improves glucose tolerance and promotes cardiac changes. This study evaluated the influence of creatine supplementation and HITT on glycemic profile and cardiac morphology in rats.

Methods

Male Wistar rats (n=60) were allocated into four groups: sedentary control (C), control + creatine supplementation (Cr), control + physical exercise (Ex), and creatine supplementation + physical exercise (ECr). C and Ex groups were treated with standard commercial chow; Cr and ECr received the same chow supplemented with creatine 2%. Rats from Ex and ECr groups underwent into a treadmill‐HIIT protocol, 5 times per week, for 12 weeks. At the end of the experiment, glycemic profile was analyzed by glucose and insulin tolerance tests (GTT and ITT, respectively), and functional capacity was assessed by maximal exercise test on treadmill. Cardiomyocyte cross‐sectional area and myocardial collagen interstitial fraction were evaluated in left ventricle histological sections stained with hematoxylin‐eosin and Picrosirius red, respectively. Statistics: two‐way ANOVA and Tukey.

Results

Functional capacity was improved in exercised groups compared to respective controls. Considering glycemic response in GTT, the area under curve (AUC) was lower in Ex and ECr than in C and Cr. In ITT, AUC was lower in Ex than C and ECr. Atria weight and atria weight‐to‐body weight ratio were higher in ECr than Ex and atria weight‐to‐body weight ratio was higher in Cr than C. Heart weight‐to‐body weight ratio was higher in ECr than Cr and Ex. Left and right ventricle weight was similar between the groups. Myocyte cross‐sectional area (C 227±26, Cr 216±22, Ex 284±27, ECr 297±7 μm2) and left ventricle collagen interstitial fraction (C 1.96±1.79, Cr 1.98±1.28, Ex 2.36±2.00, ECr 2.49±1.80 %) were higher in Ex and ECr than C and Cr.

Conclusion

HIIT improves glucose and insulin tolerance. Creatine supplementation impairs insulin tolerance in exercised rats. HIIT promotes cardiomyocyte hypertrophy and increases myocardial collagen interstitial fraction without significant influence of creatine supplementation.

Support or Funding Information

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.