bluuebunny/crossref_metadata_2025 huggingface dataset:
Renin gene expression is regulated by Chicken Ovalbumin Upstream Promoter Transcription Factor II (COUP‐TF II)
Authors: Lachmann Peter , Mayer Sandra , Roeser Marc , Ishii Sumiyashi , Suh Jae Mi , Harlander Sabine , Desch Michael , Brunßen Coy , Morawietz Henning , Tsai Sophia Y. , Tsai Ming‐Jer , Hohenstein Bernd , Hugo Christian , Todorov Vladimir T.
Published: June 2021

We aimed to investigate the involvement of the nuclear receptor COUP‐TFII in the regulation of renin gene expression.

Protein‐DNA binding studies demonstrated that COUP‐TFII binds to the proxDR sequence in the proximal renin promoter. Knockdown of COUP‐TFII in the renin‐producing cell lines As4.1 and Calu‐6 reduced the stimulation of renin mRNA expression by cAMP agonists. The mutation of the proxDR element in renin promoter reporter gene constructs abrogated the inducibility by cAMP. The proxDR sequence was essential for the function of a renin promoter cAMP‐response element. Knockdown of COUP‐TFII or cAMP‐binding protein (CREB) decreased the basal renin gene expression. When CREB was knocked down, the deficiency of COUP‐TFII did not further diminish the renin expression. Mice deficient in COUP‐TFII have lower renin expression than their control strain. Surprisingly, there was no significant difference in both plasma renin concentration and blood pressure between wildtype and COUP‐TFII‐deficient mice. Altogether our data show that COUP‐TFII is involved in the control of renin gene expression. To better characterize the role of COUP‐TFII for the renin production in vivo we are generating mice with selective COUP‐TFII deletion in the renin‐producing cells of the kidney.
Discovery of new renal Ang II processing enzyme activity using mass spectrometry and gene deletion mouse models
Authors: Grobe Nadja , Elased Khalid M , Salem Esam SB , Gurley Susan B , Ong Frank S , Bernstein Kenneth E , Schmaier Alvin H , Morris Mariana
Published: June 2021

Angiotensin (Ang) converting enzyme 2 (ACE2) is expressed in the kidney and exerts its renoprotection via conversion of the vasoconstrictor Ang II to the vasodilator Ang‐(1–7). To better characterize the tissue distribution and activity of enzymes involved in Ang II processing novel in situ and in vitro mass spectrometric methods were used. Mouse kidney sections (12 μm) or kidney homogenates (20 μg protein) were incubated with 0.1–10 nmol Ang II at pH 4–10 for 5–30 min at 37 ºC. Ang (1–7) was predominantly formed in renal cortex and dependent on amount of Ang II and pH. Further, the contribution of alternative renal peptidases to ACE2 independent formation of Ang‐(1–7) was explored using gene deletion mouse models deficient of ACE2, prolyl carboxypeptidase (PCP) or prolyl endopeptidase. Results suggest that ACE2 processes renal Ang II under neutral and basic conditions (pH>;6), while PCP catalyzes this reaction at acidic pH (pH<6). Using type 1 and type 2 diabetic animals, renal ACE2 was increased while renal PCP was decreased. This is the first report to demonstrate that renal Ang II processing to Ang‐(1–7) is independent of ACE2. Elucidation of renal Ang II processing pathways should be clinically important in patients with metabolic and renal disease.
Complementation of juxtaglomerular cell granulation in Ren‐ 1d null mice by human renin
Authors: Buckley Charlotte , Nelson Robert , Sharp Matthew , Flemming Stewart , Kenyon Christopher , Mullins Linda , Steppan Dominik , Mullins John
Published: June 2021

Mice null for the Ren‐1d gene lack renin storage granules in their juxtaglomerular cells and exhibit altered macula densa morphology. Three lines of transgenic mice carrying a 55kbp transgene encompassing the human renin (hRen) locus were generated and crossed onto a Ren1d‐null background. Expression of hRen was seen to restore granulation in juxtaglomerular (JG) cells in a transgene expression level‐dependent manner, suggesting that a threshold level of renin expression is required for the formation of dense renin‐containing granules. Complementation of the phenotype by the human enzyme suggests that hRen and mouse Ren1d share conserved epitopes required for trafficking renin into the regulated secretion pathway and hence for granulopoiesis. To dissect the granulation phenotype in detail, 2D electron microscopic (EM) images were taken of kidney sections, which were then reconstructed in 3D to show the full extent of renin granular structure. As expected, the expression of hRen, which does not effectively cleave mouse angiotensinogen, was unable to restore macula densa morphology, indicating that a locally active RAS is required for normal macular densa structure and function.
Capsaicin: a novel dietary therapeutic agent in human small cell lung cancers
Authors: Stover Cody A , Crabtree Clayton M , Dom Aaron M , Lau Jamie K , Brown Kathleen C , Shiflett Brandon , Witte Theodore R , Hardman W Elaine , Dasgupta Piyali
Published: June 2021

Capsaicin, spicy ingredient of chili peppers, is used to topically treat pain and inflammation associated with a variety of diseases. However, emerging evidence shows that it can induce apoptosis in different transformed cell types in vitro and in animal models. The present study examines the apoptotic activity of capsaicin in human small cell lung cancer (SCLC). Here we show that capsaicin induced apoptosis in a panel of human SCLC in a concentration‐dependent and time‐dependent manner. Most importantly, capsaicin caused robust apoptosis in a panel of human SCLC cell lines, but did not affect normal human lung epithelial cells. The dietary administration of capsaicin decreased the growth H69 and DMS53 human SCLC tumors xenotransplanted in nude mice. The apoptotic activity of capsaicin was reversed with the generalized TRPV antagonist ruthenium red, indicating that TRPV receptors are involved in capsaicin induced apoptosis. However, antagonists to TRPV1, namely capsazepine and SB‐366791, did not affect the apoptotic activity of capsaicin, suggesting the involvement of TRPV1‐independent mechanism. In contrast, depletion of TRPV6 by siRNA ablated the apoptotic activity of capsaicin. Our findings suggest that capsaicin may have potential applications as a novel agent for management and therapy of human SCLCs.
Wound healing activity of (−)‐borneol complexed to chitosan bioactive film in rodents
Authors: de Souza Siqueira Barreto Rosana , da Silva Prado Douglas , Galvão Juliana Gouveia , da Cunha Gonsalves Joyce Kelly Marinheiro , de Souza Nunes Rogéria , Albuquerque‐Júnior Ricardo Luiz Cavalcanti , Soares Rosilene Calazans , de Lucca Waldecy , Quintans‐Junior Lucindo
Published: June 2021

The aim of this study was to investigate the wound healing activity of (−)‐borneol complexed to chitosan film on excision wound model in rats.

Excision wound:

Sixty rats, Wistar, 250–300 g were anesthetized and an excisional wound was performed. The animals was treated with placebo (inert chitosan bioactive film), (−)‐borneol 0.5% and (−)‐borneol 1%, for 3 and 7 days. The residual wounds were analyzed and removed. The activity of the enzyme myeloperoxidase was analyzed at 3 days. Serial histological sections were obtained and stained by histochemical techniques (Hematoxilin‐Eosin – HE and Sirius red) and immunohistochemical techniques. Experimental protocols were approved by the Animal Care and Use Committee at the Federal University of Sergipe (CEPA#01/2011). The results suggest that the chitosan bioactive film with (−)‐borneol reduced (p < 0.05) wound areas, induced earlier granulation tissue formation and increased cell proliferation when compared to the control group. And the chitosan bioactive film with (−)‐borneol 0.5% and (−)‐ borneol 1% decreased (p < 0.05) the activity of the enzyme myeloperoxidase. It is suggested that (−)‐borneol modulates the wound healing process.
Gastroprotective effects of latex from Himatanthus drasticus in models of acute gastric lesion.
Authors: Pinheiro Rachel Sindeaux Paiva , Marques Larisse Mota , Freitas Lyara Barbosa Nogueira , Luz Patrícia Bastos , de Figueiredo Ingrid Samantha Tavares , Matos Mayara , Souza Tamires , Rangel Gisele , Ramos Márcio Viana , de Alencar Alencar Nylane Maria Nunes
Published: June 2021

Himatanthus drasticus (Apocynaceae), a laticifer plant, is popularly known as janaguba. This latex has been widely used in traditional folk medicine to treat diseases such cancer and ulcer. This study was performed to investigate the gastroprotective activity of proteins isolated from latex Himatanthus drasticus (HdPL) in gastric ulcer model. Experimental protocols were registered on the Institutional Ethics Committee under number 43/2011. Swiss male mice were treated with PrLP at doses 0.5; 5 and 50 mg/kg (i.v.; n=8). After 30 min they received 0.2 ml of absolute ethanol per oral, after 60 min, the animals were sacrificed, stomachs removed and analyzed the lesion index and dosage of GSH (reduced glutathione) and nitrite. To study the gastroprotective mechanism, its relations to capsaicin‐sensitive fibers, endogenous prostaglandins, nitric oxide, ATP‐sensitive potassium channels and cGMP were analyzed. HdPL gastroprotective effect was observed only at dose of 5mg/kg. HdPL also restored the GSH levels and nitrite in mucosa and only L‐NAME, Glibenclamide and ODQ were able to reverse the protective effect of PrLP. We can conclude that the HdLP has pharmacological activity with gastroprotetor effect in the gastric mucosa. This protection appears to be mediated in part by modulation of NO/cGMP/KATP pathway, which has been related to mucosal defense and maintenance of stomach's blood flow. Support: CNPQ ans CAPES.
Role of AKAP79 in â1‐Adrenergic receptor resensitization and recycling
Authors: Li xin , Bahouth Suleiman W.
Published: June 2021

AKAPs (A‐kinase anchoring proteins) have been shown to participate in macromolecular signaling complexes that include protein kinases, phosphodiesterases, ion channels, and also GPCRs. In this study, we examine the role of AKAP79 (also known as AKAP79/150) in the trafficking of β1‐Adrenergic Receptor in vitro in HEK‐293 cells and in neonatal cardiac myocytes derived from AKAP150 homozygous knock out mice.

Selective down regulation of AKAP79 in HEK‐293 cells and in rat neonatal cardiac myocytes, inhibited the recycling of the WT β1‐AR in HEK‐293 cells and the reintroduction of siRNA‐resistant AKAP79 rescued the recycling of the agonist‐internalized β1‐AR. Furthermore, in neonatal ventricular myocytes derived from AKAP150−/− mice or from AKAP150+/+ the β1‐AR was internalized, but did not recycle in myocytes from AKAP150−/− mice. The recycling of the β1‐AR was rescued by AKAP79, indicating that AKAP79 was required for the recycling of the β1‐AR to occur and shows that these studies across a spectrum of different cells yielded the same result. In addition we tested the effect of three different truncated mutants of AKAP79, namely AKAP79 [1–360] (ΔPKA‐binding site), AKAP79 [115–412] (Δmembrane and PKC binding domains] and AKAP79 [ΔPIX] (Δcalcineurin‐binding domain] their ability to recapitulate the effect of full‐length AKAP79 on recycling of the β1‐AR in AKAP79‐knock down cells. Immunopricipitation data showed that the interaction between the mutants and β1‐AR remained unchanged. However, none of these AKAP79 mutants was capable of rescuing the recycling of the β1‐AR in HEK‐cells, indicating the entire molecule of AKAP79/150 was required for this effect. Funded by NIH HL‐085848.
Mouse Flower‐like (mFl), a membrane protein involved in endocytosis?
Authors: Mannebach‐Götz Stefanie , Frohnweiler Katja , Wissenbach Ulrich , Flockerzi Veit
Published: June 2021

Recently, a novel membrane protein in Drosophila melanogaster was shown to be localized in presynaptic vesicles. It appears to mediate a Ca influx after vesicle fusion with the plasma membrane. Disruption of the corresponding gene leads to endocytic defects in flies. Apparently, this protein could serve as a Ca channel required for endocytosis. In addition it may determine clonal selection by forcing cells to undergo apoptosis.

We have identified a protein in mouse which shares 26,3% amino acid sequence identity with the fly protein and which we call mouse Flower‐like or mFl. The mFl protein is encoded by a gene on chromosome 2. In addition to the “full length” mFl protein (mFlA), 3 shorter variants were identified (mFlB, D, E). After expression of the His‐SUMO‐mFlA‐fusion protein in E. coli and removal of the tag the purified protein was used for immunization of rabbits. The anti‐mFl antibody recognizes mFl variants in brain, pancreas, kidney, thymus, liver, lung and colon. Using RT‐PCR mFlA transcripts could be identified additionally in heart, spleen and mast cells.

To analyze mFl functions we are generating mFl deficient mouse lines. The targeting strategy for conditional inactivation of the gene offers the option to study the cellular localization of mFl. Currently we have 11 heterozygous mFl transgenic mice; they will be crossed with Cre or Flp expressing mice to get mFl deficient animals.
Pregnanolone Hemisuccinate Inhibits NMDA Receptors with Selectivity for the NR1A/2A Subtype
Authors: Sugunan Kavitha , Downing Scott , Gibbs Terrell T. , Farb David H.
Published: June 2021

Glutamate receptors play a major role in relapse of cocaine addiction. Effective treatments for prevention of relapse are still lacking. Previously, our laboratory has shown that pregnanolone hemisuccinate (3α5βHS or PAHS), the synthetic analogue of pregnanolone sulfate, inhibits reinstatement of cocaine seeking behavior in rats. In order to determine the mechanism of action of 3α5βHS, recombinant NMDA, AMPA and GABAA receptors were expressed in Xenopus laevis oocytes and two electrode voltage‐clamp recordings were performed. We observed that 3α5βHS inhibits all four subtypes of the NMDA receptor with similar efficacies (about −20%). However, the potency at the NR1A/2A subunit combination is 10 to 30 fold higher as compared with the NR1A/2B, 2C, and 2D subtypes. The EC50 for NR1A/2A is 0.32μM, whereas the EC50's for the NR1A/2B, 2C, and 2D subtypes are 4.3μM, 12.3μM and 9.8μM, respectively. Four subtypes of the GABA‐A receptor (α1β2γ2s, α2β2γ2s, α3β2γ2s, and α5β2γ2s) are inhibited by 3α5βHS with potencies ranging from 6–9μM and maximum efficacy of −18%. The AMPA receptor subtype GluR1 is slightly inhibited by 3α5βHS, however, 3α5βHS has no effect on GluR3 and the heteromeric GluR1/R2 receptor. The use of a multifunction compound acting on multiple receptor subtypes such as 3α5βHS may be effective in the treatment of cocaine seeking.
Alternative polyadenylation mediated shortening of the Hsp70.3 3′UTR increases polyribosome loading of the mRNA transcript
Authors: Gabanic Andrew , Paulding Waltke , Roessler Anne , Luther Kristin , Smith Leah , McGuinness Michael , Tranter Michael
Published: June 2021

Introduction

Heat shock protein 70.3 (Hsp70.3) expression is increased in response to cellular stress and plays a cytoprotective role, including a cardioprotective role in the heart against ischemia/reperfusion (I/R) injury. Recent work from our lab shows that Hsp70.3 expression following I/R is controlled through alternative polyadenylation (APA). Truncation of the 3′UTR removes potential regulatory sequences and is observed concomitant with upregulation of Hsp70.3 expression. Herein, we investigated the hypothesis that APA truncation of the 3′UTR enhances polysome loading of the Hsp70.3 transcript.

Methods

Sucrose gradient ultracentrifugation was used to isolate polysome bound mRNA from HL‐1 cardiac myocyte cells subjected to control (long 3′UTR) or a 1 hr heat shock (HS; short 3′UTR).

Results

Cells subjected to HS for one hour showed a decrease in the total amount of polysome loaded mRNA. The Hsp70.3 transcript found in the polysome dense fractions existed as a higher ratio of the APA truncated short 3′UTR, thus supporting our hypothesis that APA truncation of the Hsp70.3 3′UTR increases polysome loading.

Our results provide an enhanced understanding of APA on the regulation of Hsp70.3 and will have a significant impact in understating the regulation of cardiac gene regulation after I/R injury.

This work was partially funded by a University of Cincinnati Provost Pilot Research Project grant (MT).
A novel redox‐based epigenetic signaling mechanism for opioids
Authors: TRIVEDI MALAV , Hodgson Nate , Shah Jayni , Deth Richard
Published: June 2021

Objective

To study the involvement of different opioid receptors and downstream signaling pathways for maintaining redox homeostasis via epigenetic regulation of gene expression.

Methods and Results

We investigated acute and long‐term effects of selected opioid drugs on EAAT3‐mediated transport of cysteine, a precursor for glutathione (GSH) synthesis. Subsequent changes in GSH/GSSG and methylation capacity were measured. Mechanistic investigations suggested temporal involvement of different G‐proteins and downstream signaling protein‐kinases. 5‐Methyl cytosine levels and global DNA methylation levels were also measured. Genome‐wide mRNA expression microarray analysis revealed temporal effects of morphine on transcription. qRT‐PCR analysis showed changes in mRNA levels of enzymes and transporters involved in GSH synthesis, methylation and transulfuration pathways. Redox and methylation responses upon removal of opioids after a prolonged exposure (in‐vitro washout) was also observed.

Our findings suggest a novel mechanism for opioid drugs, involving changes in redox status and global DNA methylation mediated by multiple downstream signaling pathways. This mechanism may contribute to opioid drug abuse, tolerance, withdrawal phenomenon and may lead to development of therapeutic interventions.

Funding Agency: National Institute of Drug Abuse.
Identifying the Role of Vascular Adaptation in the Genesis of Isolated Systolic Hypertension
Authors: Ostgaard Alexander K. , Renfro Audrey L. , Parizek Kurt A. , Nguyen Phuc H. , Quick Christopher M.
Published: June 2021

Isolated systolic hypertension (ISH) is a chronic human disease characterized by an increase in mean and pulse pressure. This increase is attributed to structural changes that result in an increase in the arterial modulus of elasticity (E) and wall thickness (h), both of which decrease arterial compliance. The causes of ISH have been difficult to identify in human studies because changes in pulse pressure causes a change in compliance, and a change in compliance causes a change in pulse pressure. We therefore employed a realistic human arterial system model to manipulate these processes independently and identify the role of adaptive processes in the genesis of ISH. First, we employed the classical arterial model developed by Westerhof (1968) to determine regional pulsatile pressures from arterial lengths, radii, h and E, and Laplace's law to determine circumferential wall stresses. Then, we assumed that h increases with mean wall stress, and E decreases with pulsatile wall stress. Reported values of pulse pressure, flow, h and E emerged from this complex interaction of hemodynamics and adaptation. Although increases in mean pressure yielded modest increases in pulse pressure and h, it failed to produce an increase in E. The only way to reproduce increases in pulse pressure, h, as well as E was to decrease the sensitivity of the adaptive response of E to pulsatile wall stress—simulating a failure of mechanotransduction.
Effects of the Diabetic Microenvironment on Esp expression
Authors: Fedorko Alyssa Michelle , Irwin Regina , Zhang Jing , McCabe Laura R
Published: June 2021

Type 1 (T1) diabetes is characterized by hyperglycemia, little to no insulin production and bone loss as a secondary complication. Decreased bone formation by osteoblasts is the major contributor to this outcome. Osteocalcin is a protein secreted by mature osteoblasts which deposits into bone mineral and circulates in the blood to influence insulin secretion and sensitivity in tissues. Esp is a gene that codes for the protein tyrosine phosphatase OST‐PTP. This protein suppresses osteocalcin expression by suppressing osteoblast insulin receptor activity. Little is known about what factors regulate Esp expression and if it is altered in metabolic diseases such as T1‐diabetes. Our study examined Esp mRNA level changes in osteoblasts exposed to diabetic conditions in vitro and in vivo. Esp expression was significantly decreased in the bones of T1‐diabetic mice which was similar to osteoblasts cultured under high glucose conditions or mannitol. When osteoblasts were co‐cultured with diabetic mouse bone marrow, osteoblast Esp expression was suppressed. TNFα antibody treatment blocked Esp suppression indicating that inflammation reduces Esp expression. In summary, our data suggests that the T1‐diabetetic microenvironment contributes to the suppression of Esp expression in osteoblasts which could influence bone and body metabolism.
Alterations in renal hemodynamics are associated with increased renal MMP‐2 expression during the early phase of diabetic nephropathy
Authors: Slaughter Tiffani , Kojima Naoki , Roman Richard , Williams Jan Michael
Published: June 2021

The aim of the present study was to compare the early changes in proteinuria, renal hemodynamics and matrix metalloproteinase‐2 (MMP‐2, marker of renal injury) expression in type‐1 diabetic SS rats that are susceptible to renal injury versus diabetic Sprague Dawley (SD) rats that are resistant to renal disease. Rats were fed a low salt diet (0.3% NaCl) to minimize the development of hypertension and injected with streptozotocin (STZ, 50 mg/kg, i.p.) to induce diabetes. Blood glucose levels were similar in both strains 3 weeks after diabetes (487±53 mg/dL). Proteinuria increased to 227±19 mg/day in diabetic SS rats while it only increased to 28±5 mg/day in diabetic SD rats. Mean arterial pressure was significantly increased in diabetic SS rats compared to diabetic SD rats (124±4 vs. 106±7 mmHg, respectively). Three weeks of diabetes caused a 2‐fold rise in glomerular filtration rate in both strains; however, renal blood flow was significantly higher in diabetic SS rats compared to values observed in diabetic SD rats. The expression of the active form of MMP‐2 protein was markedly increased in the renal cortex of SS rats compared to SD rats when treated with STZ for 3 weeks. These data suggest that the upregulation in renal MMP‐2 expression may be due to the hyperglycemia‐mediated elevation in hemodynamic stress to the glomeruli leading to the development of severe proteinuria in the SS strain compared to the SD strain.
Balancing Complexity and Simplicity in Mathematical Models of Fontan Circulations
Authors: Mohiuddin Mohammad W , Knezek Sarah F , Quick Christopher M
Published: June 2021

Characterizing heart‐arterial‐venous interaction in the healthy adult is quite complicated. Blood pressures and flows depend on a large number of critical parameters, including compliances and contractilities of two ventricles, as well as arterial compliances, venous compliances and resistances of both systemic and pulmonary circulations. The additional complexity of the staged Fontan to palliate single ventricle physiology has made characterization insurmountable—the single ventricle and vasculature adapt not only to large changes in pressure after each of three surgeries, but also to large changes in blood volume in a rapidly growing infant. Mathematical models promising to elucidate the physiology of Fontan circulations have been too simple, lacking adaptive responses to altered hemodynamics. They also have been too complex, requiring numerical solutions that are exquisitely sensitive to assumed parameter values and are notoriously difficult to interpret. We therefore modified standard minimal models of each of the stages of the Fontan procedure to simplify the model equations. We then added select adaptive processes that modify cardiac and vascular properties. Because the resulting model solutions are algebraic, mean pressures and volumes are expressed explicitly in terms of critical cardiovascular parameters. The result is a novel tool that is complex enough to trust, yet simple enough to use.
Expression of (pro)renin receptor and angiotensin II type 1 receptor on bone marrow‐related neurons in the central nervous system
Authors: Kimball Christie Diane , Li Wencheng , Zsombok Andrea , Derbenev Andrei , Francis Joseph , Raizada Mohan K , Feng Yumei
Published: June 2021

We previously reported an anatomical connection from cardiovascular (CV)‐related brain nuclei to the bone marrow (BM) and an alteration of mesenchymal stem cell (MSC) colony‐forming ability during Ang II‐induced neurogenic hypertension. This study was conducted to determine if renin‐angiotensin system (RAS) components exist in BM‐related neurons, which will lay a foundation for study of the role of brain RAS in MSC regulation during hypertension. A retrograde pseudorabies virus (PRV) with a green fluorescent protein (GFP) tag was injected into the femoral bone marrow of mice (n=3). Six days post‐inoculation, mice were perfused with 4% paraformaldehyde and brains were harvested for immunostaining for GFP, angiotensin II type 1 receptor (AT1R), and (pro)renin receptor (PRR). PRR and AT1R were localized in BM‐related neurons in several CV regulatory brain regions, including the nucleus of the solitary tract, the rostral ventrolateral medulla, and most notably in the paraventricular nucleus (PVN) of the hypothalamus. The data suggests that key receptors of brain RAS are present in the BM‐related neurons and might play a role in the regulation of MSCs during the development of neurogenic hypertension.
Prenatal hypoxia programs adult cardiac contractile dysfunction through changes in beta‐adrenergic signaling
Authors: Lindgren Isa , Holm Ann‐Charlotte B Svensson , Altimiras Jordi
Published: June 2021

Prenatal hypoxia leads to fetal growth restriction and increased risk of adult cardiovascular disease. We have previously shown that adult cardiac beta‐adrenergic receptor (βAR) desensitization is programmed by prenatal hypoxia. Our objective was to determine how the observed βAR desensitization affects cardiac contractility in vivo and whether it is linked to changes in cAMP accumulation, β1AR/β2AR ratio or G‐protein expression. Eggs were incubated in normoxia (N, 20.95% O2) or hypoxia from day 0 (H, 14% O2), hatched and raised to 5wks of age. Echocardiograms were recorded in anesthetized birds before and after isoproterenol stimulation. cAMP accumulation in isolated cells after stimulation with isoproterenol, β1AR/β2AR ratio and Gs and Gi expression in tissue was also assessed. Prenatal hypoxia caused contractile dysfunction as shown by a decrease in systolic diameter. cAMP levels after βAR stimulation and β1AR/β2AR ratio were lower in hypoxic incubated birds. Gi expression was unchanged while Gs was increased. Our results resemble those reported in early human heart failure. We conclude that prenatal hypoxia has a programming effect on adult βAR function and speculate that the 5 week chicken exposed to prenatal hypoxia is displaying early signs of heart failure. Supported by FORMAS Centre of Excellence in Animal Welfare Science and career grant from Linköpings universitet to JA.
Ski inhibits Scleraxis function: Effect on collagen expression in cardiac myofibroblasts
Authors: Zeglinski Matthew , Cunnington Ryan , Davies Jared , Kavosh Morvarid , Gupta Shivika , Bathe Krista , Rattan Sunil , Czubryt Micheal , Dixon Ian
Published: June 2021

Elevated collagen deposition and increased tissue stiffness is the primary contributor to cardiac dysfunction following MI. Ski acts as a cellular brake to modulate phenoconversion of cardiac fibroblasts to myofibroblasts. Ski is associated with reduced collagen and removal of myofibroblasts from damaged heart tissues. Conversely, Scleraxis accelerates expression of collagens in cardiac myofibroblasts. We suggest that a balance exists between pro‐ and anti‐fibrotic pathways in the healthy heart and that Ski and Scleraxis are key mediators.

Determine the role that Ski has on Scleraxis expression and the deposition of collagens by cardiac myofibroblasts during cardiac fibrosis.

Cardiac fibroblasts were isolated from rat hearts and P1 cardiac myofibroblasts were infected at varying MOI's (10, 25, 50) with sh‐Ski or sh‐EGFP (50) control virus for 6 days. Cells were harvested for cell phenotyping and analysis of fibrillar collagens.

A progressive increase in Scleraxis protein expression was noted with increasing sh‐Ski MOI from 10 to 50. This corresponded with a significant increase in mature collagen protein expression suggesting that Ski regulates Scleraxis ability to induce collagen synthesis by cardiac myofibroblasts in vitro.

Ski inhibits Scleraxis function eg, to stimulate expression of collagens in cardiac myofibroblasts indicating the existence of a feedback loop between Ski and Scleraxis.
Adenosine A2A and A2B receptors differentially modulate signal transduction and collagen production in murine cardiac firboblasts
Authors: Zhan Enbo , McIntosh Victoria , Wang Fangfei , Maruthi Rohit , Kadi Bassel , DeMerle Matthew , Lasley Robert
Published: June 2021

Both A2A and A2B adenosine receptors (AR) can modulate organ fibrosis, but their role in cardiac remodeling remains unclear. The aim of this study was to assess the functional expression of A2A and A2BR on cardiac fibroblasts (CF), cells that play a crucial role in collagen deposition in the post‐MI heart. CF were isolated from hearts of C57BL/6 mice and cultured for one passage. AR expression was measured by real time quantitative PCR. CF were treated for 10 min with 500 nM of A2A agonist (CGS‐21680, CGS) or A2B agonist (BAY 60–6583, BAY) to assess ERK and AKT phosphorylation. Additional CF were treated for 24 hr with 500 nM CGS, 500 nM BAY or non‐selective AR agonist NECA (5 μM) to assess collagen production. Western blotting was used to assess phosphorylation and total expression of ERK and AKT, as well as procollagen 1A (Pro‐1A) expression. The expression level of A2BR was double A2AR (in % GAPDH, 1.3 vs 0.6). CGS and BAY increased ERK phosphorylation (359±85% and 263±45% respectively, p<0.05). BAY reduced AKT phosphorylation by 73±4% (p<0.05), while CGS had no effect. A2BR stimulation with BAY (157±46%) and NECA (107±31%) increased Pro‐1A (p<0.05 vs vehicle), more‐so than A2AR stimulation with CGS (87±21%, p>;0.05). In conclusion, both A2AR and A2BR stimulation increased ERK phosphorylation, but only A2BR increased collagen production. These findings indicate that CF A2BR may contribute to post‐MI cardiac remodeling.
Functional characterization of KLK 8 in cardiomyocytes: cardioprotection and induction of hypertrophy
Authors: Ni Xin , Cao Buqing , Zhu Xiaoyan , Zhao Wei , Tang Zhiping
Published: June 2021

Kallikrein‐related peptidase 8 (KLK8), a member of the tissue KLK family, has been identified in various tissues. The roles of KLK8 in cardiac pathologies remain unknown. In the present study, we found that KLK8 expression was upregulated in both hypertrophic hearts and hearts subjected to ischemia‐reperfusion injury. KLK8 overexpression attenuated whereas KLK8 knockdown exacerbated hypoxia/reoxygenation‐induced injury in primary cardiomyocytes of neonatal rat. The protective effects of KLK8 were abolished by kinin B2 receptor antagonist and in kinin B2 knockdown cells. Knockdown of KLK8 attenuated phenylephrine‐induced cardiomyocyte hypertrophy. Overexpression of KLK8 induced cardiomyocyte hypertrophy, which was reversed by serine protease inhibitors, but not by kinin receptor antagonists. KLK8 overexpression resulted in a significant increase in epidermal growth factor (EGF) level in the culture media, which was abolished by serine protease inhibitors. EGF receptor antagonist AG1478 and siRNA targeting EGF receptor blocked the hypertrophic effects of KLK8 in cardiomyocytes. In conclusion, KLK8 initiates anti‐apoptotic effect cardiomycytes via kinin B2 receptor, whereas it induces hypertrophy through EGF/EGFR signaling.

This work is supported by NSFC (No. 31000516) and Science and Technology Commission of Shanghai Municipals (09XD1405600).
Relationship Between Dyslipidemia and Hypertension (HBP) in Male ZDSD, a New Rat Model of Metabolic Syndrome (MetS)
Authors: Eaton David M , Rogers Ashley N , Rice Ami E , Coy Kathy , Peterson Richard G , Packer C Subah
Published: June 2021

MetS is epidemic and a leading cause of cardiovascular disease. The current study addressed the hypothesis that HBP develops as a consequence of dyslipidemia in a new leptin‐intact rat model, ZDSD. Cholesterol, triglyceride (TG) and BP were recorded weekly in ZDSD and CD obese controls from 6–23 weeks. Hypercholesterolemia and hypertriglyceridemia preceded HBP while diabetes was delayed. Scatter plots and linear regression were used to identify potential correlations. Student's t‐test and ANOVA followed by Neuman‐Keul's were used to determine differences between mean values for two groups or multiple groups, respectively. CD cholesterol levels were lower than in ZDSD throughout the study. However, rate of increase with aging was ~2× greater in CD than ZDSD. ZDSD had higher TGs than CD throughout the 17 weeks. While TG levels declined in both groups as cholesterol levels rose with aging, TG rate of change was 1.3× greater for ZDSD. ZDSD BP was higher than CD BP at all life stages. ZDSD became hypertensive by 9 weeks and BP rate of change was 1.9× greater for ZDSD. Interestingly, both TG levels and BP peak at about the same time in ZDSD when rats are 12–16 weeks with rise in BP slightly lagging rise in TGs. A surprising finding is the concomitant resistance of obese CD to develop hypercholesterolemia and hypertension.

(D Eaton was a NSF LSAMP Scholar)
Sympathetic and metabolic changes induced by hyperglycemia in myocardial infarction
Authors: Malfitano Christiane , Carbonaro Mariana , de Souza Alcione Lescano , Lopes Andressa B , Casarini Dulce Elena , Curi Rui , De Angelis Katia , Irigoyen Maria Claudia
Published: June 2021

This study was designed to evaluate the beneficial effects of hyperglycemic metabolism after myocardial infarction as well as changes in sympathetic marker.

Male Wistar rats were divided into control (C), diabetic (D), myocardial infarction (MI) and diabetic myocardial infarction (DMI). Left coronary artery occlusion was performed after 15 or 30 days of diabetes (STZ) an accompanied by 2 or 15 days, respectively. The ventricular function, glycerol and norepinephrine levels were evaluated by echocardiography, biochemical kit and HPLC, respectively. The lipolysis was assessed by enzymes extracted from periepididymal adipose tissue. The area of infarction was 36% lower in DMI vs MI and the ejection (DMI: 82 ± 3 vs MI: 55 ± 3%) and shortening fraction (DMI: 48 ± 2 vs MI: 25 ± 2%) were preserved in DMI in comparison with MI. The glycerol was kept in 2 (2261 ± 180 mg/dl) and 15 (2756 ± 402 mg/dl) days after coronary occlusion in DMI, with 70% and 20% reduction in the weight of the adipose and adipocyte diameter as compared with D. The glycerol was decreased in MI after 2 (6245 ± 998) vs 15 (4355.45 ± 341mg/dl) days of MI vs C (7166 ± 1001mg/dl). Moreover, norepinephrine levels were decreased the MI group (5 ± 0.5 pg/ml) compared to the DMI (13 ± 1pg/ml). The results suggest an enhanced lipolysis in the MI group. Furthermore, diabetic animals had reduced infarcted area and improved ventricular function. These findings may be related to the increase in norepinephrine levels at the heart and the maintenance of lipolysis in this group, keeping thermogenesis in similar state as compared to normoglycemic animals.
Effect of oligomerized polyphenol supplementation on lipid metabolism during exercise in healthy men
Authors: Miyake Tatsuki , Sato Koji , Matsutani Kenji , Iemitsu Motoyuki , Nishizawa Mikio , Miura Takehito , Isaka Tadao , Fujita Satoshi
Published: June 2021

Previous studies have shown that oligomerized polyphenol (OLG) supplementation reduced visceral fat in obese; however, role of OLG on lipid metabolism during exercise has not been tested. Therefore, the purpose of current study was to investigate the effect of OLG supplementation on lipid metabolism during a bout of aerobic exercise. OLG (100mg/day) and placebo (CON) were given for 14 days in 10 healthy young men by a double‐blind, randomized, cross‐over design. After an overnight fast on the 15th day, exercise test (50% VO2max for 30min on bicycle ergometer) was conducted. Blood samples were taken before, during, and up to 30min‐post exercise for analysis of hormones and metabolites. Insulin resistance as assessed by HOMA‐IR tended to be lower in OLG as compared to CON (P=0.09). Plasma glycerol as well as free fatty acid concentration increased significantly 15 to 30min post‐exercise in OLG as compared to CON (P<0.05). Moreover, % change in serum growth hormone was higher in OLG as compared to CON during exercise (P<0.05). In summary, 14 days of OLG supplementation significantly increased exercise‐induced GH response and subsequent lipolysis in response to a bout of aerobic exercise in young men.
Nox4 NADPH Oxidase‐dependent Mitochondrial Oxidative Stress Promotes Cardiovascular Disease in Aging
Authors: Runge Marschall S , Vendrov Aleksandr E , Madamanchi Nageswara R
Published: June 2021

We examined the interplay of aging, oxidative stress (OS) and cardiovascular disease (CVD) using mouse models of OS. We recently reported that prolonged mitochondrial OS in aged SOD2+/− mice causes aortic stiffness and cardiac dysfunction by inducing aortic smooth muscle cell (SMC) stiffness, apoptosis and wall remodeling. We now report that aged apoE−/−/SOD2+/− had significantly increased aortic stiffening and atherosclerosis, and vascular mitochondrial reactive oxygen species (mtROS) and aortic SMC apoptosis compared with aged apoE−/− and young apoE−/−/SOD2+/− mice. In contrast to the effect in young, Nox1/Nox2 NADPH oxidase inhibition failed to attenuate atherosclerosis in aged apoE−/−/p47phox−/− mice. The lack of protection is correlated with increase in ROS and Nox4 expression in VSMC and aortas of aged mice as well as increased mtROS in VSMC. Aged apoE−/− and apoE−/−/p47phox−/− mice also had impaired vascular and cardiac function. Increased Nox4 expression in VSMC of aged mice is associated with increased mitochondrial dysfunction and mtDNA damage and suppression of Nox4 in VSMC attenuated mtROS levels. Nox4 expression also increased with age in both human aortic SMC and carotid arteries and is correlated with human atherosclerotic lesion severity. These data indicate that Nox4‐dependent mitochondrial OS plays a critical role in age‐associated increase in mitochondrial ROS, dysfunction and CVD.
Ovariectomy (OVX) in 60 week‐old C57BL/6J mice with standard chow diet significantly increases body weight and fat mass, VEGF expression and angiogenesis in adipose tissue
Authors: Makey Kristina , Chinchar Edmund , Howie Carissa , Huang Min , Miele Lucio , Gu Jian‐Wei
Published: June 2021

The diet‐independent mechanism contributing to postmenopausal obesity remains unclear. Previous study showed that OVX in 12 week‐old mice with standard chow diet did not lead to obesity. The present study determines whether OVX in age‐relevant old mice with standard chow diet leads to obesity and increases VEGF expression and angiogenesis in adipose tissue. OVX (n=4) and shamOVX (SHM; n=4) was performed in 8 sixty week‐old C57BL/6 mice, and followed by a standard chow diet for 12 weeks. We monitored food intake and weight gain. The lean mass (LM) or fat mass (FM) composition was monitored by EchoMRI. Although food intake was similar, OVX mice gained 26% more body weight than SHM mice (P<0.05), due to increased FM (10.4±1.4 vs. 5.9±0.6 g; P<0.05), with no changes in LM. OVX mice had 70% increased visceral fat than SHM mice (P<0.01), in which there were increased VEGF expression (354±41 vs. 486±65 pg/mg; P<0.05) and an increased ratio of capillaries to adipocytes (CD31 immunohistochemistry). These findings suggest that this mouse model mimics human disease, in which postmenopausal women develop obesity even without a high fat diet. Postmenopausal obesity is associated with increased VEGF expression and angiogenesis in adipose tissue. (NIH/AA013821 and NIH/HL051971)
MMP‐9 dependent early biomarkers of cardiac aging
Authors: Yabluchanskiy Andriy , Ma Yonggang , Chiao Ying Ann , Lopez Elizabeth , Zhang Jianhua , Jin Yu‐Fang , Lindsey Merry L
Published: June 2021

Aging is a major risk factor for cardiac morbidity and mortality. Previously, we showed that cardiac aging is associated with a decreased E/A ratio, which was preserved in the matrix metalloproteinase‐9 (MMP‐9) null mice. To evaluate plasma changes that occur before cardiac dysfunction, we examined 15–18 month old wild type (WT, n=16) and MMP‐9 null (null, n=21) mice. By Doppler, the E/A ratios were similar between the 2 groups (1.42±0.05 in WT vs. 1.38±0.06 in null). Of 60 analytes evaluated in plasma, 2 were lower and 6 were higher in the null group. The percent differences were −20% for CD40, −46% for haptoglobin, 129% for immunoglobulin A, 35% for lymphotactin, 13% for macrophage colony stimulating factor−1, 28% for stem cell factor, 16% for vascular cell adhesion molecule‐1, and 50% for von Willebrand factor (all p<0.05). These results suggest that MMP‐9 deletion decreases age‐associated inflammation before cardiac function is impaired.
Flow‐mediated dilation responses to exogenous testosterone administration in healthy males
Authors: Ely Brett R , Miner Jennifer A , Miner Jonathon C , Kaplan Paul F , Minson Christopher T
Published: June 2021

Flow‐mediated dilation (FMD), a measure of shear‐induced endothelium dependent vasodilation, varies between sexes and is influenced by sex hormones. The relationships between FMD and estrogen and progesterone have been examined in women, but little is known about the effects of short‐term testosterone administration on FMD in healthy young men. The purpose of this study was to examine FMD following short‐term administration of exogenous testosterone in young men.

Methods

Five young, healthy, male volunteers underwent FMD before (Pre) and after (Post) seven days of topical testosterone administration (Androgel 1.62%, 120mg/d). FMD was assessed by occlusion and release of a forearm cuff with simultaneous brachial artery ultrasound and Doppler analysis.

Results

Testosterone administration resulted in an increase in serum testosterone (Pre: 553±198 ng/dl; Post: 780±50 ng/dl; Δ +40 to +595 ng/dl), while there was a trend toward a decreased FMD following testosterone administration (Pre: 10.7 ± 5.0%; Post: 6.9 ± 3.5%; Δ −0.03 to −10.88%; p=0.12).

Conclusions

Short‐term exogenous testosterone administration appears to attenuate FMD in healthy men, despite serum testosterone levels remaining within a normal physiologic range. Supported by NIH Grant HL081671.
The effect of fructose on risk of incident hypertension: a systematic review and meta‐analysis of 3 large U.S. prospective cohorts
Authors: de Souza Russell Jude , Jayalath Viranda H , Sievenpiper John L , Ha Vanessa , Kendall Cyril WC , Beyene Joseph , Jenkins David JA
Published: June 2021

Background

There is concern that fructose contributes to the development of hypertension.

Aims

To determine the association between fructose and incident hypertension, we performed a systematic review and meta‐analysis of prospective cohort studies.

Methods

We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library (through November 1, 2012) for relevant prospective cohort studies. We pooled relative risks (RR) using a generic inverse variance random effects model, and assessed (Q‐statistic) and quantified (I2) between‐cohort heterogeneity. The Newcastle‐Ottawa scale assessed study quality.

Results

Three prospective cohort studies (n=37,375 men & 185,855 women) were included with 58,162 confirmed cases of incident hypertension (11,192 in men; 46,970 in women) over 2,502,357 person‐years follow‐up. Median energy‐adjusted fructose intake was 13.9 to 14.3% of total calories in the highest quintiles and 5.7 to 6.0% in the lowest quintiles, assessed by validated semi‐quantitative food‐frequency questionnaires. The RR of incident hypertension (highest vs. lowest quintile) was 1.02 (95% CI: 0.99 to 1.04), with no evidence of heterogeneity (I2=0%; P=0.59).

Limitations

Only 3 cohorts from a single country (U.S.) were represented.

Conclusion

Fructose was not associated with risk of hypertension in 3 large U.S. prospective cohorts. Funding: CIHR, Calorie Control Council
Hyperthermic hyperventilation is not mitigated by cardiopulmonary baroreceptor loading
Authors: Lucas Rebekah A. I. , Pearson James , Schlader Zachary J , Crandall Craig G
Published: June 2021

This study tested the hypothesis that cardiopulmonary baroreceptor loading would reverse increases in ventilation and decreases in end‐tidal carbon dioxide (CO2) that accompany hyperthermia. Ten individuals (29±5 y; 76±12 kg) underwent passive heat stress via a water perfused suit while intestinal temperature (HQ Inc.), mean skin temperature, central venous pressure (central venous catheter, CVP, n=8), minute ventilation, tidal volume (Parvo‐Medics) and end‐tidal CO2 (capnograph, PETCO2) were monitored. After intestinal temperature was elevated 1.9 ±0.5°C, causing a sustained rise in ventilation (by 2.9 ±2.8 L/min), and reductions in PETCO2 (by 4 ±3 mm Hg) and CVP (by 4 ±1 mm Hg), 19 ±2 ml/kg of warmed saline was rapidly (over 5–10 min) infused intravenously to increase CVP and return cardiopulmonary baroreceptor loading towards normothermic levels. Saline infusion increased CVP by 5 ±1 mm Hg (P <0.01) but did not change (P >;0.05) ventilation, tidal volume or PETCO2. Intestinal and skin temperatures did not change (P >;0.05) with saline infusion. The absence of a reduction in ventilation upon returning cardiopulmonary baroreceptor loading to pre‐heat stress levels indicates that hyperthermic hyperventilation is not caused by cardiopulmonary baroreceptor unloading coincident with the heat stress. Supported by NIH Grant HL061388
The sensitivity of lowered shift of core temperature threshold for thermoregulation to insulin is associated with insulin response to glucose during passive heating in men
Authors: Suzuki Akina , Okazaki Kazunobu , Yokoyama Hisayo , Imai Daiki , Takeda Ryosuke , Naghavi Nooshin , Miyagawa Toshiaki
Published: June 2021

Esophageal temperature (Tes) threshold (ΔTH) for thermoregulation is shifted to lower temperature by hyperinsulinaemia with glucose compare to fructose intake. We assessed if the sensitivity of lowered shift of ΔTH to insulin was associated with insulin sensitivity.

Methods

Seven healthy young men performed two trials in a climate chamber (28°C of Ta, 40% of RH). After 10 min baseline (BL), subjects consumed 75 g of glucose (GLU) or fructose (FRU) with 300 ml of water. After 20 min, they were heated passively by lower legs immersion (42°C) for 60 min. Tes, sweat rate and cutaneous vascular conductance at forearm were measured, and ΔTH for sweating and cutaneous vasodilation were determined. Insulinogenic index (ISI) which has a hyperbolic relationship with insulin sensitivity was calculated as increase of plasma insulin concentration ([Ins]p) from BL to 30 min after intake divided by that of plasma glucose concentration in GLU.

Results

ΔTH for sweating and cutaneous vasodilation in GLU (0.26±0.04 °C and 0.38±0.05 °C) were lower than FRU (0.39±0.05 °C and 0.54±0.06 °C). The sensitivities of lowered shift of both ΔTH to a given increase in [Ins]p from FRU to GLU at 30 min after intake were negatively correlated with ISI (10.0±1.5 IU/mmol) (R =−0.76 and −0.62).

Conclusion

The sensitivity of lowered shift of core temperature threshold for thermoregulation to insulin is correlated with an index of insulin sensitivity.