bluuebunny/crossref_metadata_2025 huggingface dataset:
Endothelial TRPV4 Channel Function is Impaired in Pulmonary Arterial Hypertension
Authors: Marziano Corina , Hong Kwangseok , Cope Eric Lee , Sonkusare Swapnil K.
Published: June 2021

Endothelial dysfunction contributes to the pathogenesis of pulmonary arterial hypertension (PAH) by reducing arterial vasodilation. Endothelium‐dependent vasodilation is an important regulator of pulmonary vascular resistance (PVR) and overall pulmonary arterial pressure (PAP). We recently identified endothelial TRPV4 (transient receptor potential vanilloid 4) channels as important regulators of vasodilation in pulmonary arteries (PAs), and showed that unitary Ca2+ influx events through TRPV4 channels, termed TRPV4 sparklets, activate endothelial nitric oxide synthase (eNOS) to cause vasodilation. Reduced NO bioavailability is a hallmark of endothelial dysfunction in PAH. However, the mechanisms underlying reduced NO bioavailability in PAH are not well understood. We hypothesized that impairment of TRPV4 channel function attenuates NO release in PAH. PAH was induced in mice using three‐week chronic hypoxia (CH) and Sugen 5416 + CH models. Mouse right ventricular pressures (RVP) were measured as an indicator of PAP. RVP was significantly higher in TRPV4−/− mice when compared to the control mice after three weeks of CH. High‐speed Ca2+ imaging was used to analyze TRPV4 sparklets in the native endothelium from resistance‐sized, fourth‐order PAs. Vascular diameter studies were performed on isolated, pressurized (15 mmHg), small PAs. Ca2+ imaging studies were also performed in PAs obtained from control and PAH patients. In CH and Sugen 5416 + CH models, TRPV4 sparklet activity and TRPV4 channel‐dependent vasodilation were significantly lower compared to normoxic control mice. However, TRPV4 mRNA expression and immunofluorescence were not altered in both mouse models of PAH, suggesting an impairment in the regulation of channel function rather than channel expression. TRPV4 sparklet activity was also consistently lower in PAs from PAH patients, when compared to control patients. Elevated levels of superoxide radicals have been shown to contribute to the development of PAH. Superoxides can react with NO to form peroxynitrite (PN). A PN scavenger, uric acid, restored TRPV4 channel activity in CH mice. We, therefore, hypothesized that PN‐induced impairment of TRPV4‐dependent Ca2+ signaling inhibits endothelial function in PAH. Indeed, PN attenuated TRPV4 sparklet activity in a reversible manner. Our results support the concept that PN‐induced regulation of TRPV4‐dependent Ca2+ signaling may contribute to the development of PAH. Moreover, altered TRPV4 channel activity may contribute to the reduced NO bioavailability in PAH.

Support or Funding Information

1R56HL138496, 5R00HL121484, 17PRE33660762

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Endothelial SIRT1 prevents age‐induced impairment of vasodilator responses by enhancing the expression and activity of soluble guanylyl cyclase
Authors: Wang Yu , Guo Yumeng , Xu Cheng , Man Andy WC. , Vanhoutte Paul M.
Published: June 2021

Rationale

Aged arteries are characterized by attenuated vasodilator and enhanced vasoconstrictor responses, which contribute to endothelial dysfunction in vascular diseases such as arterial hypertension, atherosclerosis and heart failure. SIRT1 is a longevity regulator exerting protective functions against vascular ageing, although the underlying mechanisms remain largely unknown.

Objective

The present study was designed to elucidate the signaling pathways involved in endothelial SIRT1‐mediated vasodilator responses during arterial aging. In particular, the contributions of nitric oxide (NO), endothelial NO synthase (eNOS), cyclooxygenase (COX) and/or soluble guanylyl cyclase (sGC) were examined.

Methods and Results

Wild type (WT) or endothelial NO synthase knockout (eKO) mice were cross‐bred with those overexpressing human SIRT1 selectively in the vascular endothelium (EC‐SIRT1). Arteries were collected from the four groups of mice (WT, EC‐SIRT1, eKO and eKO‐SIRT1) to measure isometric relaxations/contractions in response to various pharmacological agents. In arteries of WT animals, decreased NO bioavailability, hyper‐activated COX signaling and downregulated sGC expression/activity collectively contributed to the increased vasoconstrictor and decreased vasodilator responses during ageing. Arteries of EC‐SIRT1 mice were protected from ageing‐induced alterations in smooth muscle relaxation/contraction and the vasodilator responses. Overexpression of endothelial SIRT1 did not block the reduction in NO bioavailability, but attenuated the hyper‐activation of COX‐2; the latter effect resulted in an inhibition of endothelium‐dependent contractions in arteries of EC‐SIRT1 and eKO‐SIRT1 mice. The sGC β1 subunit was significantly upregulated by endothelial overexpression of SIRT1 and the expression remained higher in arteries of old EC‐SIRT1 than those of age‐matched WT mice. Disruption of endothelial SIRT1 function downregulated sGC β1 expression. Moreover, overexpression of endothelial SIRT1 enhanced the relaxations to NO‐independent sGC stimulators in arteries of EC‐SIRT1 and eKO‐SIRT1 mice.

Conclusions

Endothelial SIRT1 prevents age‐induced impairment of vasodilatation largely by inhibiting COX‐2‐mediated endothelium‐dependent contractions and enhancing sGC‐mediated smooth muscle relaxation, independently of eNOS and NO signaling.

Support or Funding Information

This work was financially supported by the grants from Research Grant Council of Hong Kong (780613M and 17121714), Hong Kong Health and Medical Research Fund (13142651 and 13142641), Collaborative Research Fund of Hong Kong (C7055‐14G) and the National Basic Research Program of China (973 Program 2015CB553603).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Inhibition of acid sphingomyelinase‐mediated autophagic flux contributes to amitriptyline‐induced perturbation of tube formation in murine endothelial cells
Authors: Guan Yinglu , Li Xiang , Koka Saisudha , Zhang Yang
Published: June 2021

Amitriptyline is an inhibitor of lysosomal acid sphingomyelinase (gene symbol Smpd1) and a well‐known tricyclic anti‐depressant with cardiovascular side effects. We previously reported that loss of acid sphingomyelinase function leads to defective autophagic flux and enhanced dedifferentiation in vascular smooth muscle cells. However, it remains unknown whether amitriptyline has any cardiovascular side effects on the angiogenic capability of vascular endothelial cells and whether such effect is associated with impaired autophagy signaling pathways. Using an aortic ring assay, we demonstrated that the wild‐type aortas treated with amitriptyline or Smpd1+/− aortas exhibited decreased endothelial tube outgrowth from small slices of aorta embedded in Matrigel indicating attenuated ex vivo angiogenesis. Similarly, amitriptyline or Smpd1 gene silencing perturbed the tube formation capability of cultured mouse microvascular endothelial cells (MVECs). The inhibitory effect of amitriptyline on angiogenesis in MVECs was correlated with decreased activation of angiogenic signaling (phosphorylation of eNOS, Akt, and Erk1/2) and reduced endothelial cell proliferation. Mechanistically, amitriptyline alone had no effect on autophagy induction in MVECs but inhibited autophagic flux as shown by increased expression of LC3B and p62. Blockade of autophagic flux by lysosome function inhibitor bafilomycin or chloroquine mimics the effects of amitriptyline on angiogenic signaling, proliferation, and tube formation in MVECs. Collectively, these data suggest that defective acid sphingomyelinase‐mediated autophagic flux contributes to the cardiovascular side effects and toxicity of amitriptyline on proliferation and angiogenic capability of vascular endothelial cells.

Support or Funding Information

National Heart, Lung, and Blood Institute grants (HL122769, HL122937)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Biphasic Electrical Stimulation Promotes Insulin Release
Authors: Siegel David , Thompson David , Mower Morton , Ross David
Published: June 2021

Biphasic (anodal pulse followed immediately by a cathodal pulse) electrical stimulation (10Hz, 5 ms duration) of rat insulinoma (Ins‐1) cells resulted in a 2–3‐fold increase in insulin release over 30 min that was stimulation period‐ and voltage‐dependent. Electrical stimulation of tissue culture medium (in the absence of cells) did not increase insulin release when subsequently added to cells, confirming that the insulin released by electrical stimulation was not due to substances generated by the culture medium. Electrical stimulation‐induced insulin release occurred in the absence or presence of glucose. Calcium channel blockade (using nifedipine or verapamil) inhibited basal insulin secretion and insulin secretion evoked by electrical stimulation, demonstrating that electrical stimulation‐induced insulin release involved activation of voltage‐dependent calcium channels and was not a non‐specific effect of stimulation on the plasma membrane. Basal insulin secretion and the increase in insulin release induced by electrical stimulation were also inhibited by the mitochondrial poisons antimycin A or oligomycin A, suggesting a role for mitochondrial function in insulin secretion. Electrical stimulation of cells also resulted in a more pronounced uptake of MitoTracker Red by mitochondria, indicating a more negative inner mitochondrial membrane potential. The failure of cells to accumulate the fluorogenic dye Cytotox green confirmed that electrical stimulation was not significantly disrupting the plasma membrane or inducing overt toxicity to the cells during the period of stimulation. These results provide further evidence that biphasic electrical stimulation can exert significant biological effects and elicit insulin release in a manner that is dependent upon mitochondrial activity and calcium channel activation but independent of glucose.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Multi‐Omic Approach to Identifying Altered Metabolic and Signaling Pathways in the Mouse Heart with Chronic Exposure to Atypical Antipsychotic Medications
Authors: Beauchemin Megan , Nevola Kathleen , Guntur Anyonya R. , Barlow Deborah , Le Phuong T. , Vary Calvin , Motyl Katherine J. , Duarte Christine , Houseknecht Karen L.
Published: June 2021

Atypical (AA) antipsychotic drugs, including Risperidone (RIS) and Olanzapine (OLAN), cause cardiac arrhythmia and significant endocrine and metabolic risk factors for cardiovascular disease, including obesity, insulin resistance, hyperglycemia, and dyslipidemia. AA drugs have complex pharmacology, antagonizing G‐protein coupled receptors including: dopamine, serotonin, α‐adrenergic and muscarinic receptors. However, the underlying pharmacology linking cardiovascular morbidities to AA therapy is unknown. We hypothesize that AAs may alter cardiac energy metabolism and present early gene expression markers in the pathogenesis to cardiovascular disease. In this study we aim to investigate the mechanisms by which AAs may promote cardiometabolic dysfunction. Male B6 mice were dosed daily with either 5 mg/kg OLAN or 1 mg/kg RIS or vehicle control (V) for 4 weeks and chronic effects of AAs were assessed in whole heart ventricles by RNAseq, miRNAseq and Proteomic analysis. Results suggest changes in transcriptomic and proteomic profiles and in the mouse heart with chronic exposure to AAs relating to mitochondrial dysfunction, lipid oxidation and metabolism, contractility, cardiac hypertrophy and PPAR signaling. Further pathway analysis of these data sets using Ingenuity Pathway Analysis revealed altered canonical pathways and disease and function that are consistent between the RIS and OLAN treated groups compared to V. To further investigate the effect of AA treatment on cardiac mitochondrial function, cardiac mitochondria were isolated from female B6 mice dosed 4 weeks daily with V or 0.75 mg/kg RIS and oxygen consumption studies were performed on the XF24 extracellular flux analyzer (Agilent) to measure various respiratory states. Isolated mitochondria were well coupled and showed a RCR (OCRADP/OCROligo) of ~ 3. RIS treatment led to an increase in State II (Succinate) and State III (phosphorylating) respiration compared to V. In conclusion, our data demonstrate chronic effects of AAs on cardiac mitochondrial function and bioenergetics and indicators of cardiac function.

Support or Funding Information

This work was funded in part by NIH grant DK095413 awarded to KH and NIH grant AR067858 awarded to KJM.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Protective RhoA Signaling Regulates Drp1 and Mitochondrial Fission in Cardiomyocytes
Authors: Brand Cameron S. , Tan Valerie P. , Brown Joan Heller , Miyamoto Shigeki
Published: June 2021

Cardiac ischemia/reperfusion injury occurs due to oxidative stress resulting from loss of blood flow and its subsequent restoration. Oxidative stress leads to dysfunction and death of cardiomyocytes, increasing risk of progression to heart failure. We have shown previously that signaling through activation of the small G‐protein RhoA protects against ischemia/reperfusion injury by blocking pro‐apoptotic mitochondrial signals in cardiomyocytes. Alterations in mitochondrial dynamics, in particular mitochondrial fission, have been suggested to play a role in cardioprotection. We tested the hypothesis that activated RhoA signaling also regulates mitochondrial fission in cardiomyocytes. The protein Drp1 translocates from the cytosol to the mitochondria to promote fission. Our studies show that adenoviral expression of active RhoA in cardiomyocytes stimulates phosphorylation of Drp1 at serine‐616, a phosphorylation residue associated with increased translocation of Drp1 to the mitochondria. Accordingly, active RhoA also increases Drp1 protein levels in mitochondrial fractions. Both responses are blocked by inhibition of ROCK, a kinase downstream of active RhoA. Endogenous RhoA activation by the GPCR agonist sphingosine‐1‐phosphate (S1P), a lysophospholipid signaling ligand associated with cardioprotection, also increases Drp1 phosphorylation and mitochondrial Drp1 through the S1P3 receptor subtype. Consistent with the role of mitochondrial Drp1 in fission, expression of active RhoA in cardiomyocytes promotes accumulation of smaller mitochondria through ROCK and Drp1, as assessed by fluorescence confocal microscopy. A Drp1 S616A mutant is not phosphorylated and, when expressed in cardiomyocytes, did not increase in mitochondrial fractions in response to active RhoA. In addition, expression of mutant Drp1 inhibits mitochondrial fission in response to active RhoA. Oxidative stress, induced by hydrogen peroxide, leads to cardiomyocyte cell death which is attenuated by activated RhoA. This protective effect of RhoA activation is blocked by siRNA knockdown of Drp1. Taken together, our findings demonstrate that RhoA activation can regulate Drp1 to induce mitochondrial fission, and that this response is involved in cardioprotection due to RhoA. We propose regulation of Drp1 by RhoA activation as a novel mechanism to provide protection in response to acute cardiomyocyte injury.

Support or Funding Information

This research was funded by NIH grants T32HL007444 (CSB) and R37HL028143 (JHB).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Reprogramming Human Cardiac Progenitor Cells into Pacemaker Cells for Heart Repair
Authors: Raghunathan Suchi , Iyer Dinakar , Potaman Vladimir , Schwartz Robert J. , McConnell Bradley K.
Published: June 2021

Heart Failure (HF) accounts for 5.7 million deaths annually, which often are the result of acute or chronic ischemic injury due to myocardial infarction (MI). MI is associated with cardiomyocyte death succeeded by scar tissue formation. This scar tissue serves as a mechanical barrier and prevents normal electrical conductivity through the ventricles, thus contributing to the development of arrhythmias. Various stem cell therapies for cardiac repair are directed towards replacing injured myocardium with healthy cardiomyocytes. However, a primary concern with these therapies is their inability to synchronize electromechanically with the recipient myocardium, leading to arrhythmia and aggravating HF symptoms. Our study objective was to use a novel reprogramming strategy to convert human adipogenic mesenchymal stem cells (hADMSCs) first into cardiac progenitor cells (CPCs) and then into conducting Pacemaker‐like cells. Previously, we have shown successful reprogramming of hADMSCs to form CPCs using human transcription factors ETS2 and MESP1. We demonstrated cardiomyocyte phenotype based on gene expression, calcium transients, histology, and polarization wave conduction maps. Interestingly in our current studies, we have optimized a unique cocktail of transcription factors for reprogramming of CPCs into Pacemaker‐like cells using lentiviral vectors. The CPCs treated with transcription factor combinations were initially screened for Pacemaker‐like cells by FACS sorting for mcherry reporter gene specific for pacemaker cells. Following which we assayed these cells for pacemaker marker genes. We observed a robust induction of Pacemaker marker genes, by qPCR gene expression assays. We then validated the functional efficiency of Pacemaker‐like cells in‐vitro through voltage patch clamp recording. Interestingly, the patch clamp recording of the Pacemaker‐like cells exhibited “funny currents” demonstrating the functional characteristic of pacemaker cells. The characteristic of these conduction cells will be further validated by optical mapping in ex‐vivo studies. These studies will facilitate the development of an optimal Pacemaker‐like cell‐based therapy within failing hearts through the recovery of lost contractile and electrical function between cardiomyocytes.

Support or Funding Information

The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes ofHealth (NIH);Center for the Advancement of Science in Space (CASIS)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Tiger nut extracts inhibit cell migration, RhoA, and RhoC GTPases, but induce Rac1/2/3 in MCF7 and MDA‐MB231 cancer‐origin cell lines
Authors: Achoribo Seyram Elom , ONG Ming Thong
Published: June 2021

Background/Aims

Breast cancer is the most common female cancer worldwide. The high mortality of breast cancer patients is increasing over the years due to the late stage discovery of the cancer when the cancer cells may have already metastasized. In many developing and underdeveloped countries such as Ghana, the delay in cancer detection is partly due to the cost of the various treatments available which forced the women to first fall on orthodox medicine or herbal products. A proper investigation and mechanism of action of known medicinal plants to help alleviate this burden is therefore needed. Tiger nut is an underutilized crop in Ghana, with high nutritional values, but consumed raw as snack or blended for its milk. A study on its antioxidant and cytotoxicity effects showed that it has an anti‐proliferative effect on MCF7 and MDA‐MB‐231 breast cancer‐origin cell lines. This work investigated the effects of Tiger nut extracts on the migration and invasion of the mentioned cell lines, and on the Rho GTPase pathways.

Methodology

Cell lines were cultured in DMEM (Low glucose) supplemented with 10 % FBS, and 1 % penicillin. The migration effect was studied by the scratching assay where plated cells were wounded, treated, incubated and pictures taken at 0 h, 12 h, and 24 hours time points. The invasion assay was performed using Matrigel invasion kits on MDA‐MB‐231. Finally, cytoplasmic proteins were extracted by lysing the cells with Thermo‐Fisher mper lysis buffer and Western blotted for Rho A, Rho C, and rac1/2/3.

Results

Aqueous and Ethanol extracts have been found to inhibit the migration of the investigated cell lines. However, only ethanolic extract was found to reduce the invasiveness of MDA‐MB‐231 at almost 50 %. Rho A, and Rho C were down‐regulated by all extracts whereas Rac1/2/3 was up‐regulated in MCF7.

Conclusion

Rho A and Rho C are known to positively contribute to tumour progression. Their down‐regulation might therefore be responsible for the inhibition in cell migration observed. Even though the over expression of Rac may assemble lamellipodia at the leading edge of the cell, the down regulation of the Rho A, and C could not generate the contractile force needed to migrate. Thus, the cell will be static or round up in case of absence of Rho B, which may be the reason of the anti‐proliferative behaviour observed from previous studies.

Support or Funding Information

The work was supported by Universiti Sains Malaysia. Seyram Elom Achoribo is recipient of The World Academic of Sciences‐Universiti Sains Malaysia (TWAS‐USM) fellowship.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Omega‐3 polyunsaturated fatty acids protect monocytes adhesion to endothelial cells induced by Mac‐1 expression through FFA4 in monocytes
Authors: Lee Seung‐Jin , Im Dong‐Soon
Published: June 2021

A G protein‐coupled receptor (GPCR) named free fatty acid receptor 4 (FFA4, also known as GPR120) was found to act as a GPCR for omega‐3 polyunsaturated fatty acids (n‐3 PUFA). Recently, FFA4 is known to participate in the progression of atherosclerosis, however, the underlying mechanisms are unclear. Thus, this study investigated the molecular mechanisms responsible for monocyte adhesion to the vascular endothelium, which is a key early event in macrophage foam cell formation. In ex vivo study, LPS‐induced the primary monocyte adhesion to the vascular endothelial cells were significantly attenuated by pretreatment of EPA and DHA, a representative n‐3 PUFA. This EPA and DHA‐induced inhibition were blunted by primary monocytes isolated from FFA4 (−/−) mice. In in vitro study, The LPS‐induced monocyte adhesion to the endothelial cells and adhesion molecule, Mac‐1 expression were significantly attenuated by pretreatment of EPA and DHA in monocytes. This EPA and DHA‐induced inhibition was blunted by pretreatment of AH7614 (a FFA4 antagonist) and by transfection of FFA4 siRNA, suggesting a pivotal role of FFA4 on LPS‐induced monocyte adhesion to the endothelial cells and Mac‐1 expression. In addition, in promoter activity analysis and chromatin immunoprecipitation assays to identify transcription factors involved in EPA and DHA inhibited LPS‐induced Mac‐1 expression, both AP‐1 and NF‐κB played central roles to increase Mac‐1 transcription in LPS‐treated monocytes. The results of this study suggest that n‐3 PUFA protect monocyte adhesion to vascular endothelial cells and Mac‐1 expression via signaling pathways involving AP‐1 and NF‐κB by activating FFA4 in monocytes, leading to increased foam cell formation in the development of atherosclerosis.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Diuretic Effect of Cassia occidentalis Leaf and Seed Extracts in Sprague Dawley Rats
Authors: Blair Trisha Alexandria , Thomas Everton , Lindo Lisa , McGrowder Donovon , Singh Paul
Published: June 2021

Objective

To evaluate the diuretic activity of Cassia occidentalis leaf and seed extracts, and to determine their effects on AST and ALP levels in Sprague Dawley rats.

Method

Diuretic activity of hexane, ethyl acetate, methanol and aqueous extracts from the leaves and seeds of Cassia occidentalis (100 mg/kg) were evaluated using the Lipschitz model in Sprague Dawley rats. (n=6). Frusemide (20 mg/kg) was used as the positive control. All substances were administered orally. Animals were placed in metabolism cages and urine collected over a 24 hrs period. Results were represented as urine volume per body weight (mL/kg). Sodium, potassium and chloride ion concentrations in urine were also determined. Blood was collected before and 24 hrs after administration of extracts to obtain AST and ALP levels using an auto analyser system.

Results

The mean urine volume collected from groups administered methanol and aqueous extracts from leaves of Cassia occidentalis were 19.02 mL/kg (p=0.009) and 18.81 mL/kg (p=0.017) respectively. Aqueous extract from the seeds of Cassia occidentalis was the only extract from the seeds that produced an increase in mean urine volume (20.78 mL/kg; p=0.003). Urine volume produce by all three extracts were significantly higher when compared to control (9.80 mL/kg). Sodium, potassium and chloride ion urine concentrations significantly increased after the administration of methanol and aqueous extract from the leaves of Cassia occidentalis. Frusemide produced a mean urine volume of 39.48 mL/kg (p<0.001) and an increase in sodium, potassium and chloride ions concentration.

All groups were observed to have a reduction in AST and ALP levels.

Conclusion

The study revealed that methanol and aqueous extracts from the leaves of Cassia occidentalis have diuretic effects. These extracts also significantly increased urine levels of sodium, potassium and chloride and reduced AST and ALP levels.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Attenuation of Diabetic Retinopathy by Momordica chochinchinensis through Inhibition of AGEs and PCO in Streptozotocin Diabetic Rats
Authors: Putta Swathi , Kilari Eswar Kumar
Published: June 2021

The aim of the present study was to investigate the effect of hydroalcoholic pericarp extract of Momordica chochinchinensis (HAPMC) on diabetes, oxidative stress, protein glycation and formation of advanced glycated end products (AGE) and obtain comparison with gliclazide. Albino Wistar rats were induced for diabetes by streptozotocin and divided into five groups as vehicle control (group I), disease control (group II), standard gliclazide (Group III), group IV, and V received 150, 300 mg/kg of HAPMC respectively, for a period of 12 weeks. Blood glucose levels were estimated and Cataract progression due to hyperglycemia was monitored by slit lamp biomicroscope and fundoscope at the end of every 4 weeks, the animals were sacrificed and the biochemical pathways involved in the pathogenesis of cataract such as oxidative stress by protein content, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and aldose reductase (AR) in lens homogenates, protein carbonyl content (PCO) and advanced glycation end products (AGEs) in both serum and lens of HAPMC treated diabetic rats were compared to diabetic rats. The HAPMC was shown to have significant (p<0.05) reduction of blood glucose levels compared to STZ induced diabetic rats. Slit lamp observations indicated cataract due to hyperglycemia. Progression and maturation were delayed significantly with HAPMC treatment. Photographs of fundus shows marked thickness of retina and dilated blood vessels in diabetic rats compared to control. Normal thickness of fundus and blood vessels was observed with HAPMC treatment. A significant improvement in antioxidant enzymes as SOD, CAT, GSH levels and inhibiting AR levels, and inhibition of PCO and AGE levels in lens homogenate. The histopathology of retina reveals that HAPMC treatment showed marked amelioration of all retinal cell layers damaged with STZ induction. These results suggest that the HAPMC is effective against STZ induced cataract and is beneficial in inhibition of formation of AGEs in the progression of diabetic retinopathy due to the presence of flavonoids like rutin, quercitin and kaempiferol.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Muscadine Grape Extract Improves Arterial Stiffness in Hypertensive (mRen2)27 Female Rats
Authors: Ryalat Fatima , Yamaleyeva Liliya M. , Cruz‐Diaz Nildris , Varagic Jasmina , Gallagher Patricia E. , Tallant E. Ann , Diz Debra I.
Published: June 2021

Increased arterial stiffness is an important risk factor for cardiovascular disease and target‐organ damage and is more prevalent in female subjects, as well as in the elderly. The rate of development of arterial stiffness is associated with wide pulse pressure and can be accelerated by hypertension. Grape polyphenols are known for antioxidant effects that could be protective against cardiovascular disease, especially during aging. We investigated the effects of chronic muscadine grape extract (MGE; Piedmont Research & Development Corp.) intake on aortic arch pulse wave velocity (PWV) in transgenic hypertensive (mRen2)27 female rats. The extract was administered in the drinking water (0.2 mg of total phenolics/mL) to 14‐week‐old (mRen2)27 female rats (body weight at baseline (g), MGE: 274 vs Control: 261, p > 0.05; systolic blood pressure at baseline (mm Hg), MGE: 174 ± 5 vs Control: 166 ± 4, p > 0.05). After 15 weeks of treatment, PWV was measured after acquiring the images using a preclinical ultrasound and photoacoustic system (Vevo LAZR 2100, Fujifilm, Visual Sonics). Our data show that rats treated with MGE have 16% lower PWV compared to Control (MGE: 2.40 ± 0.05 vs Control: 2.85 ± 0.09 mm/s; p < 0.01, n = 4 in each group). However, preliminary data indicate no significant treatment differences at this time point in cardiac function parameters (cardiac output, heart rate, stroke volume, ejection fraction, fractional shortening or left ventricular filling pressure). Since lower PWV is an index of less arterial stiffness, we conclude that chronic MGE treatment improves aortic stiffness in female hypertensive rats providing a potential beneficial effect on overall cardiovascular health.

Support or Funding Information

Chronic Disease Fund Research

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Antihyperglycemic Activity of Asparagus gonoclados Root Tubers in Streptozotocininduced Diabetic Rats
Authors: Chippada Apparao , Kotha Peddanna , Allagadda Rajasekhar , Badri Kameswara R.
Published: June 2021

Diabetes mellitus is the most common metabolic disorder affecting more than 422 million people worldwide. The available pharmacological approaches for the prevention and treatment of diabetes are not adequate due to associated side effects and higher costs. For centuries, ancient cultures across the globe emphasized the critical role of natural remedies in managing the diabetes by using them. Asparagus gonoclados is a traditional folk remedy used for diabetes mellitus in India. The present investigation was taken up to evaluate the anti‐diabetic activity of the A. gonoclados (Liliaceae) root tubers. Different solvent extracts (aqueous, ethanol, ethyl acetate and hexane) were prepared from A. gonoclados root tubers and were tested for anti‐hyperglycemic activity in streptozotocin induced diabetic rats and, anti‐α‐glucosidase and anti‐α‐amylase activity in vitro. Among the different solvent extracts, oral administration of ethanol extract (AGEE) of A. gonoclados, at a dose 500 mg/kg b.w, has produced maximum (67%) reduction in fasting blood glucose levels in diabetic treated rats after 6 hrs when compared to the glibenclamide (20 mg/kg b.w.) treated group. AGEE also has revealed the dose‐dependent inhibitory effect on α‐glucosidase and α‐amylase activities that is comparable to α‐glucosidase inhibitor drug, Acarbose. Phytochemical analysis of AGEE revealed the presence of steroidal saponins, sapogenins, phenols, flavonoids, phytosterols, tannins, triterpenes, carbohydrates, alkaloids and proteins. AGEE has the richest quantity of total phenolics (138.4±0.39 μg/mg gallic acid equivalents), flavonoids (64.8±0.54 μg/mg quercetin equivalents) and steroidal saponins (12.9±0.11 μg/mg sarasapogenin eqivalents). Further characterization of ethanol extract was carried out by LC‐ESI‐MS/MS analysis and fifteen compounds were identified. Our studies are the first to report anti‐diabetic activity of A. gonoclados root tubers. We conclude that A. gonoclados has potential therapeutic importance in the management of diabetes mellitus.

Support or Funding Information

This study is funded by Indian Council of Medical Research (ICMR, India) through major research project (No.45/18/2012).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Maternal and Embryo‐Fetal Historical Background Control Data in the Hsd:Sprague Dawley®SD® Rat
Authors: Horn Mandy , Williams Denita , Parker Robert
Published: June 2021

Maternal and embryo‐fetal historical background control data supports improved interpretation of lesions in reproductive toxicity studies. A maternal and embryo‐fetal toxicity study was performed to generate historical background control data in the Hsd:Sprague Dawley®SD® rat model. One hundred previously nulliparous and virgin time‐mated female Sprague Dawley rats, allotted in four subsets of 25 rats each, were housed under standard housing and husbandry conditions with ad libitum access to a standard diet (18% protein, 6% fat) and water. Rats were administered tap water (10 mL/kg body weight) by oral gavage once daily from gestational day 6 to 17. Body weight, food consumption, and clinical observations were monitored throughout the in‐life phase of the study. On gestational day 20, animals were euthanized and submitted for Cesarean section and necropsy. A macroscopic postmortem evaluation was performed on all animals, including counts of corpora lutea and implantations and uterine weights. Fetuses were removed, weighed, sexed, and examined externally for defects as well as soft tissue abnormalities and skeletal abnormalities. Placentas were examined and weighed. One hundred dams were pregnant and 100 litters were evaluated. There were 1,488 fetuses examined externally; 698 had fixed visceral evaluations and 790 fetuses had skeletal evaluations. A detailed analysis of maternal data, including body weight, food consumption, and pregnancy outcome will be presented. Fetal data including uterine and placental weights, in addition to fetal examinations, including external, soft tissue (visceral), and skeletal will also be presented. These data support the use of the Hsd:Sprague Dawley®SD® rat as a valuable toxicology model and will assist in interpretation of lesion data in future studies with this model.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Bone‐like Particles Circulate in the Peripheral Blood of 6‐ and 18‐Month‐Old Male Fischer‐344 Rats
Authors: Lee Seungyong , Guderian Sophie , Prisby Rhonda
Published: June 2021

We recently identified a novel vascular pathology whereby bone marrow blood vessels progressively ossify (i.e., calcify) with advancing age. Examination of ossified and normal blood vessels revealed ossified (i.e., bone‐like) particles (OSP) at the luminal and abluminal surfaces. We theorized that OSP gain access to the peripheral circulation and hypothesized that their frequency would augment with advancing age. Whole blood samples were collected from male Fischer‐344 rats (6‐mon, n=6 and 18‐mon, n=6) and 500 μL were processed to characterize OSP. The OSP were quantified and sorted with a BD FACSAria II flow cytometer, and imaged with confocal and scanning electron microscopy (SEM). Diameter and size distribution were assessed from 3 rats per group utilizing SEM microphotographs and Image J. Data are presented as Means ± SEM. Body mass was higher (p<0.05) at 18‐ vs. 6‐mon. The number of sorted OSP did not differ between groups (i.e., 6‐mon, 2,540 ± 492 per 500 μL and 18‐mon, 3,296 ± 868 per 500 μL). OSP ranging in diameter from <1–15 μm (6‐mon, n=47 ± 5 and 18‐mon, n=52 ± 6), 15–30 μm (6‐mon, n=12 ± 4 and 18‐mon, n=5 ± 4) and 45–60 μm (6‐mon, n=2 ± 1 and 18‐mon, n=1 ± 0.7) were present at equal frequencies between groups. However, there were more (p>0.05) OSP ranging in diameter from 30–45 μm at 6‐mon (n=3 ± 0) vs. 18‐mon (n=1 ± 0.6). SEM images revealed OSP with rough and jagged edges (Figure 1). In conclusion, OSP >15 μm may serve as emboli, and their rough morphology may damage the endothelial cell lining of blood vessels. Finally, circulating OSP potentially contribute to vascular calcification.

Support or Funding Information

Supported by NIH NIGMS P20 GM103446 Core Access Award (R. Prisby) and AHA 16IRG27550003 (R. Prisby).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Dynamic blood flow control by ATP‐sensitive K+ channel in heart
Authors: Zhao Guiling , Joca Humberto C. , Lederer W. Jonathan
Published: June 2021

Blood flow within the heart itself is tightly coupled to its metabolic needs. Despite its importance, little is known about the way the local blood flow is regulated on a beat‐to‐beat basis. This study has investigated the molecular and cellular regulatory mechanisms that control blood flow in the mammalian heart using perfused mouse cardiac papillary muscle preparation as well as cultured primary ventricular myocytes and capillary endothelial cells. State‐of‐the‐art high‐speed confocal microscopes that include a combination of XY (Nipkow disk) and point‐scanner confocals have been used to monitor the functional changes of arterioles and capillaries in heart. The preparations were examined using a temperature and flow control superfusion bath and patch clamp manipulators and instrumentation. Our results suggest that hyperpolarizing current generated by ATP‐sensitive K+ channel (KATP) in cardiomyocytes may enter apposed capillary endothelial cells through gap junctions and hyperpolarize these cells. These endothelial cells may then underlie the hyperpolarization of gap‐junction‐connected arterial smooth muscle cells that relax to produce vasodilation and blood flow elevation. An additional contribution to blood flow elevation and vascular relaxation may be attributed to extracellular K+ ([K+]o) increases around the endothelial cells (from ventricular myocyte KATP and other K+ channels). The hyperpolarization of capillary endothelial cells is due to the [K+]o‐dependent activation of inward rectifier K+ channels (Kir). Thus, the activation of KATP in cardiac myocytes caused by [ATP]i drop and/or metabolite accumulation in cardiac myocytes links the metabolism of specific myocytes to the local increase in blood flow. This mechanism is a classic negative‐feedback signaling mechanism that links ventricular myocyte metabolism to locally increased blood flow.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
New insights into the role of inducible nitric oxide synthase in Marfan syndrome associated aortic aneurysm
Authors: Talley Nicholas , Hoxha Brikena , Alexander Tia , Cameron Eryn L. , Vallejo‐Elias Johana , Esfandiarei Mitra
Published: June 2021

Marfan syndrome (MFS) is an autosomal dominant inherited disease that affects the connective tissue of large vessels throughout the human body. MFS is caused by mutations in the FBN1 gene which encodes for fibrillin‐1, a major component of extracellular microfibrils and acts as a scaffolding protein for elastin deposition, and allows for the formation of elastic fibers in the extracellular matrix of large arteries. The loss of aortic wall structural integrity leads to cardiovascular manifestations of MFS, which include the dilation of the aortic root that can lead to dissection and rupture. Previous studies have shown that the activity of endothelial nitric oxide (eNOS) has decreased in the aortic wall leading to endothelial dysfunction in MFS mice. However, we have been able to show that despite an obvious decrease in eNOS activity, the basal NO level in the aortic tissue is significantly higher in MFS mice aorta. Therefore, we aim to further determine the role that inducible nitric oxide synthase (iNOS) may play in MFS aneurysm pathogenesis by creating a MFS mouse lacking iNOS expression. In this study, wild type C75BL/6, MFS (FBN +/−) and MFS mice lacking iNOS expression (FBN+/−, iNOS−/−) were subjected to high resolution, high frequency ultrasound imaging at the age of 3 and 6 months to evaluate various cardiac and aortic parameters including aortic diameter, pulse wave velocity, cardiac ejection fraction & stroke volume, left ventricular wall thickness and mass and mitral valve early and atrial velocities (E/A) ratio. Our data shows that aortic root diameters at the aortic annulus and sinus of Valsalva, aortic pulse wave velocity, and mitral valve early velocity were greater in 3‐month old MFS mice when compared to control and MFS mice lacking iNOS expression, indicating a significant increase in aortic wall stiffness in MFS mice aorta. At 6 months of age, mitral valve early and atrial velocities and E/A ration were significantly decreased in MFS mice compared to controls and MFS mice lacking iNOS expression. In addition, measurements for aortic annulus diameter, ejection fraction, fractional shortening were markedly increased in 6‐month old MFS mice as compared to control and MFS mice lacking iNOS expression. These findings indicate that inhibition of iNOS may have some protective effects in the cardiovascular system in MFS mice, and therefore, providing valuable information about the potential therapeutic value of iNOS inhibition on cardiac and aortic function and structure in the mouse model of MFS associated aortic aneurysm.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Measurement of Electrolytes, Including Acetate in Various Physiological Samples Using Ion Chromatography
Authors: Chapp Andrew D. , Schum Simeon , Behnke Jessica E. , Huber Michael J. , Jiang Enshe , Larson Robert A. , Shan Zhiying , Chen Qing‐Hui
Published: June 2021

Accurate quantification of cations and anions remains a major diagnostic tool in understanding diseased states. The current technologies used for these analyses are either unable to quantify all ions due to sample size/volume, instrument setup/method, or are only able to measure ion concentrations from one physiological sample (liquid or solid). Herein, we adapted a common analytical chemistry technique, ion chromatography and applied it to measure the concentration of cations; sodium, potassium, calcium, magnesium and ammonium (Na+, K+, Ca2+, Mg2+, NH4+) and anions; chloride and acetate (Cl−, −OAc) from physiological samples. Specifically, cations and anions were measured in liquid samples: serum and cerebrospinal fluid, as well as tissue samples: liver, cortex, hypothalamus and amygdala. Serum concentrations of Na+, K+, Ca2+, Mg2+, Cl−, and −OAc (mM): 138.8 ± 4.56, 4.05 ± 0.21, 4.07 ± 0.26, 0.98 ± 0.05, 97.7 ± 3.42 and 0.23 ± 0.04, respectively. Cerebrospinal fluid concentrations of Na+, K+, Ca2+, Mg2+, Cl−, and −OAc (mM): 145.1 ± 2.81, 2.41 ± 0.26, 2.18 ± 0.38, 1.04 ± 0.11, 120.2 ± 3.75, 0.21 ± 0.05, respectively. Ammonium was undetectable in serum and cerebrospinal fluid. Tissue Na+, K+, Ca2+, Mg2+, NH4+, Cl− and −OAc were also measured. Validation of the ion chromatography method was established by comparing chloride concentration between ion chromatography with a known method using an ion selective chloride electrode. These results indicate that ion chromatography is a suitable method for the measurement of cations and anions, including acetate from various physiological samples.

Support or Funding Information

Funding support: AHA 16PRE27780121, Andrew Chapp, R15‐HL129213, Zhiying Shan; R15‐HL122952, Qing‐Hui Chen.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hypertensive and Pre‐Hypertensive African Green Monkeys Display Increased Proteinuria
Authors: Rhoads Megan K. , Osborn Jeffrey L.
Published: June 2021

Chlorocebus aethiops sabaeus, the African Green Monkey (AGM), is a highly translational model of spontaneous hypertension with cardiorenal pathologies and age‐dependent prevalence similar to humans with essential hypertension. Since a large majority of the patient population is diagnosed with idiopathic hypertension, the AGM represents a unique opportunity to explore the cause and consequences of elevated blood pressures in a closely related non‐human primate species that shares many physiological similarities, including diurnal rhythmicity, upright postural positioning, and complex group social dynamics. In a cohort of 40 adult male AGMs, we tested the hypothesis that hypertensive AGMs would display increased proteinuria and decreased GFR compared to normotensive controls. Animals were singly housed in metabolic pens with water ad libitum and fed non‐human primate chow twice daily. While animals were lightly sedated (ketamine, ~15 mg/kg), blood pressures were measured by forearm cuff plesythmography and whole blood was drawn. After a 1 week acclimation period, 24‐hour urine was collected for 3 consecutive days. Urine protein concentrations were measured by Pierce bicinchoninic acid assay and plasma/urine creatinine concentrations were measured by the Jaffe reaction. Animals were categorized as normotensive (NT, systolic blood pressure (SBP) < 120 mmHg), pre‐hypertensive (PHT, SBP between 120 and 140 mmHg), or hypertensive (HT, SBP >140 mmHg). Normotensive (n =11, mean SBP±SE: 109.1±4.19 mmHg), pre‐hypertensive (n=9, 129±1.61 mmHg), and hypertensive (n=20, 169.81±6.77 mmHg) animals had similar daily water intakes and urine flow rates. Glomerular filtration rate (eGFR) was similar between all three groups (NT eGFR: 1.45±0.36 mL/min; PHT eGFR: 1.34±0.17 mL/min; HT eGFR: 2.00±0.35 mL/min, p>0.05), but PHT and HT groups had significantly increased proteinuria compared to NT animals (NT: 198.47±30.71 mg/day; PHT: 492.43±68.17 mg/day, p<0.05 vs. NT; and HT: 435.22±34.59 mg/day, p<0.05 vs NT). This data suggests that in the AGM, similar to humans, renal dysfunction that may contribute to the development and/or maintenance of spontaneous hypertension, further validating the use of this species as an important and clinically relevant whole animal model for hypertension. Ongoing studies will assess glomerular and tubular morphological pathologies, albuminuria, electrolyte excretion and the contribution of sympathetic activation to blood pressure control in this novel model of spontaneous hypertension.

Support or Funding Information

Funding Sources: American Heart Association Pre‐doctoral Fellowship to MKR (16PRE30010011) and Biomedical Science Research Group, LLC

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.