bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of phytoestrogens from Curcuma comosa Roxb. on rat aorta relaxation
Authors: Intapad Suttira , Saengsirisuwan Vitoon , Suksamrarn Apichart , Piyachaturawat Pawinee
Published: June 2021

The present study aims to investigate the effect of Curcuma comosa Roxb., family Zingiberaceae, containing phytoestrogens on vascular relaxation. Isolated thoracic aorta from adult female rats were incubated with C. comosa hexane extract, and an isolated diarylheptanoid, [(3R)‐1,7‐diphenyl‐(4E,6E)‐4,6‐heptadien‐3‐ol] which is the major in the extract. Both the extract and diarylheptanoid compound enhanced the endothelium‐dependent relaxation response to acetylcholine. Co‐incubation of C. comosa with ICI182,780 (ER antagonist), L‐NAME (NOS‐inhibitor) or ODQ (guanylase cyclase inhibitor) abolished the enhancing effects. C. comosa extract and the compound also increased the phosphorylation levels of serine 1177‐eNOS and serine 473‐Akt. In addition to the acute exposure, the effects of long‐term treatment (12 weeks) of C. comosa to the ovariectomized rats (OVX) were also investigated. Both C. comosa and diarylheptanoid compound treatments resumed the impairment of endothelium functions, and increased mRNA levels of both ERα and eNOS. The results suggest that the enhancing endothelium‐dependent relaxation by phytoestrogens from C. comosa is both non‐genomic and genomic effects and mediates through ER‐dependent and NO‐pathways.

Supported by TRF through RGJ Ph.D. Program (Grant PHD/0094/2547) and research grant from TRF (DBG 5180020)
Embolic potential in symptomatic patients undergoing carotid angioplasty and stenting: evaluation of plaque instability through microscopic quantification of particulate debris
Authors: Chung Christine , Shin Hyun Joo , Shah Tejas R , Faries Peter L
Published: June 2021

Objective

Preoperative patient characteristics associated with a higher degree of embolization during carotid angioplasty and stenting (CAS) have yet to be clearly defined. Our aim is to examine whether neurologic symptoms in CAS patients is associated with greater plaque instability as determined by the quantification of intraprocedural embolic debris.

Methods/Results

We analyzed 162 filters of 233 CAS cases. Particles captured in distal protection devices were visualized by stereomicroscopy along three perpendicular axes, and were subsequently quantified through video imaging software. Due to particle shape heterogeneity, individual particle sizes were determined by greatest length. 56 patients (34%) were symptomatic [transient ischemic attack (TIA): 52%, amaurosis fugax (AF): 21%, cerebrovascular accident (CVA): 34%]. Increased particle number and size were observed in symptomatic (S) vs. asymptomatic (AS) patients: number (S: 14.2 ± 13.9 vs. AS: 7.9 ± 8.8, P<0.001), maximum size (S:1127 ± 1412 μm vs. AS: 744 ± 827 μm, P=0.03), and mean size (S: 473 ± 431 μm vs. AS: 342 ± 262 μm, P=0.02). Furthermore, specific symptoms were associated with particle characteristics to varying degrees. The presence of TIA yielded a significantly greater number (P=0.03) and mean size (P<0.001) of debris, while the occurrence of AF and CVA trended towards the same outcome.

Conclusions

The presence of neurologic symptoms increases the number and size of embolized debris in CAS patients, which may place them at greater risk for perioperative embolic complications.

Grant Funding Source: National Institute of Health K08HL073313.
CC Chemokine Receptor 5 Directs Macrophage Function Following Myocardial Infarction
Authors: Zamilpa Rogelio , Kanakia Rushit , Cigarroa Joaquin , Martinez Hernan , Jimenez Fabio , Ahuja Seema S. , Lindsey Merry L.
Published: June 2021

The CC Chemokine Receptor 5 (CCR5) is a key chemokine receptor expressed on macrophages, and CCR5 ligands are highly upregulated post‐MI. However, the role of CCR5 in post‐MI remodeling of the left ventricle (LV) has not been investigated. Accordingly, we examined LV function, plasma inflammatory markers, macrophage infiltration, matrix metalloproteinase‐9 (MMP‐9), and collagen content in wild‐type mice (WT, n=25) and CCR5 null mice (Null, n=33) at 7 days post‐MI. While MI sizes were similar between the groups (44±2% in WT and 42±2% in Null), the LV remodeling index was higher in the CCR5 null mice. The higher LV remodeling index was associated with attenuated plasma IL‐6, IFN‐γ and TNFα levels and lower LV macrophage numbers (7±1% of total infarct area compared to 11±1% in WT; p<0.05). In addition, the concomitant increases of MMP‐9 and crosslinked collagen in LV infarcts were not observed in the CCR5 null mice. These results indicated that CCR5 deletion imparted a net negative effect post‐MI by decreasing macrophage numbers to impair the inflammatory response, reduce collagen content, and increase the remodeling index. NIH (R01 HL‐75360), AHA (0855119F) to M.L.L., AHA (09POST2150178) to R.Z and VA Merit to S.S.A.
A Unique Model of Compensated Severe Pressure Overload Cardiac Hypertrophy in Rats
Authors: Gao Shumin , Hong Chull , Fritzky Luke F. , Ho David , Danridge Lauren M.A , Park Misun , Gelpi Ricardo , Vatner Dorothy E. , Vatner Stephen F.
Published: June 2021

One limitation to most rodent models of severe pressure overload is the inability to maintain normal left ventricular (LV) function chronically. We compared the effects of 4 wks transverse aortic constriction (TAC) in rats (Sprague‐Dawley, SD) and mice (FVB and C57BL6J). Interestingly, the pressure gradients from LV to aorta achieved in TAC rats averaged 145±13 mmHg, a level not feasible in mice. In FVB and C57 mice, pressure gradients were less than 105 mmHg, p<0.05, averaging 100 mmHg. Even with these lower pressure gradients the C57 mice all went into heart failure and died by 3 weeks after TAC, whereas LV ejection fraction (EF) in FVB mice, measured by echo, declined from 73±0.4% to 65±1% (n=11) after 4 wks. In contrast, SD rats responded to TAC with enhanced, p<0.05, LVEF (78±1%) compared with shams (72±2%). This occurred with an increase in LV/body wt of 61±0.1% (2.9±0.1 vs 1.8±0.1 mg/g), and no increase in either LV end‐diastolic pressure (5±1 vs 6±1 mmHg) or LV systolic wall stress (62.6±4.4 vs 65.3±0.9 dyn/cm2) compared to shams. LV diastolic function was also preserved in SD rats with TAC. In contrast, as expected, both LV end‐diastolic pressure and LV systolic wall stress increased, p<0.05, in both mouse models. Thus, the rat TAC model is unique for studying compensated, chronic pressure overload; rats tolerated a pressure gradient of roughly 150 mmHg and exhibited either normal or enhanced LV function.
Cardiac Manifestations in Hyaluronidase 2 KnockOut (KO) Mice
Authors: Chowdhury Biswajit , Hemming Richard , Jassal Davinder S , Flamion Bruno , Hombach‐Klonisch Sabine , Triggs‐Raine Barbara
Published: June 2021

Hyaluronidase 2 (Hyal2) is a GPI‐linked endoglycosidase thought to initiate the degradation of hyaluronan (HA). HA is an abundant component of the extracellular matrix where it has an important role in matrix assembly, wound healing and embryonic development. Our objective was to characterize the cardiac abnormalities detected in Hyal2 knock‐out (KO) mice. Although cardiac anomalies were not initially described in these mice, they may have been the cause of unexplained pre‐weaning lethality of Hyal2 KOs. We observed a severe cardiac phenotype in approximately 55% (n=22) of the KO mice on a C129;CD1 background. Mice exhibiting this phenotype displayed weight loss and shortness of breath ultimately leading to euthanasia between 1 and 9 months of age. Dissection of the mice exhibiting this phenotype consistently revealed a gross enlargement of either the right or left atrial chamber. Histological examination of the cardiac tissue in three of these mice revealed profound thickening of the aortic and pulmonic valves, and in one case the mitral valve, and also demonstrated increased levels of HA in the valves. Murine echocardiography confirmed that the pulmonic valve was thickened. In conclusion, Hyal2 deficiency leads to elevated HA in the heart valves and early lethality, possibly due to diastolic dysfunction. This work is supported by a grant from the Canadian Institutes of Health Research to BTR.
Fabry and fmf diseases: more that eyes can see
Authors: Vasto Sonya , Castiglia Laura , Nuzzo Domenico , Rizzo Claudia , Duro Giovanni , Caruso Calogero
Published: June 2021

Fabry disease is an X‐linked disorder resulting from a deficiency of the lysosomal enzyme alpha‐galactosidase leading to the accumulation of glycolipids in the cells. It has been demonstrated that polymorphisms of alfa‐galactosidase might influence the onset and development of inflammatory cardiovascular age related disease.

Familiar Mediterranean fever (FMF) is a autosomal recessive inflammatory based disease, characterized by recurrent fever, peritonitis, arthritis, pleuritis, and cardiac problems. MEFV encodes the pyrin protein it has been suggested to play a role in the innate immunity regulating the inflammatory response. Several data suggest a role of FMF polymorphisms in worsening recurrent inflammatory diseases. The aim of this study is to analyze the interaction between polymorphisms of this two diseases in order to find possible association. We have analyzed 46 patients with cardiac and neurological diseases holding Fabry's disease polymorphisms. Surprisingly, we have found that out of the 46 patients 9 individuals were bearing also Pyrin allelic mutations (more that 19.6%). Since the percentage of Pyrin mutation in a healthy population is more or less 5%, we can conclude that the presence of these mutations might load of further inflammatory burden the status on Fabry's patients.
Salmonella effector protein AvrA influences bacterial dissemination and persistence within the host
Authors: Jones Rheinallt , Wu Huixia , Luo Liping , Neish Andrew
Published: June 2021

Certain pathogens stably establish themselves within host cells because they have evolved mechanisms to evade elimination. For example, the intracellular enteric pathogen Salmonella secretes the AvrA acyltransferase which has suppressive effects on innate immunity and apoptosis. To determine the mechanism by which AvrA mediates these effects, we created transgenic Drosophila harboring avrA. We show that AvrA has potent and specific inhibitory activity against the JNK pathway in Drosophila and in mammalian epithelial cells. Intriguingly, we also found that AvrA expression in a background of proinflammatory stimulation resulted in increased cellular proliferation. Mechanistic assays in cultured cells showed AvrA mediated inhibition of the JNK pathway and concurrent TNF stimulation resulted in elevated ERK pathway signaling. Polarized T84 cultured cells, or primary murine bone marrow cells infected with an adenovirus expressing AvrA and stimulated with TNF also exhibited elevated proliferation compared to unstimulated or uninfected cells. Finally, elevated BrdU positive splenocytes were observed in mice infected with wild type Salmonella compared to mice infected with mutant Salmonella avrA‐. Together, these data show Salmonella has evolved a protein that influences MAPK pathways with the effect of facilitating Salmonella persistence and growth by forcing cellular proliferation.
Epigenetic regulation of high glucose‐induced proinflammatory cytokine production in monocytes by curcumin
Authors: Yun Jung‐Mi , Jialal Ishwarlal , Devaraj Sridevi
Published: June 2021

Diabetes is a pro‐inflammatory state. We have shown increased monocyte proinflammatory cytokines in patients with diabetes. High glucose (HG) induces inflammatory cytokines via epigenetic changes. Curcumin is anti‐inflammatory and may regulate chromatin remodeling by inhibiting histone acetylation. In this study, we tested the effect of curcumin on histone acetylation and inflammatory cytokine secretion under HG conditions in monocytes. THP‐1 cells were cultured in presence of normal glucose (NG, 5.5 mmol/L) or HG(25 mmol/L) conditions in absence or presence of curcumin (1.5–12.5μM) for 72h. Cytokine level, NFκB transactivation, histone deacetylases (HDACs) activity, and histone acetylases (HATs) activity were measured by immunoblotting, ELISA and immunofluorescence. HG activates HAT which in turn acetylates p65 and suppresses HDAC2 resulting in NFκB activation and increased transcription of IL‐6 and TNF‐α in monocytes. Curcumin induces HDAC2 and decreases HAT (p300) activity, thereby resulting in decreased NFκB activation and decreased inflammatory cytokine release (p<0.001) in HG conditions. These results indicate that curcumin decreases HG‐induced cytokine production in monocytes via epigenetic changes involving NFκB. In conclusion, curcumin supplementation by reducing vascular inflammation may prevent diabetic complications.

Grant Funding Source: N/A
15(S)‐Hydroxyeicosatetraenoic acid‐induced angiogenesis requires Src‐mediated Egr‐1‐dependent rapid induction of FGF‐2 expression
Authors: Kundumani‐Sridharan Venkatesh , Niu Jixiao , Wang Dong , Van Quyen Dong , Zhang Qiuhua , Subramani Jaganathan , Karri Saradasri , Rao Gadiparthi N
Published: June 2021

To understand the mechanisms underlying 15(S)‐hydroxyeicosatetraenoic acid (15(S)‐HETE)‐induced angiogenesis, we have studied the role of Egr‐1. 15(S)‐HETE induced Egr‐1 expression in a time dependent manner in HDMVECs. Blockade of Egr‐1 via forced expression of its dominant negative mutant attenuated 15(S)‐HETE‐induced HDMVEC migration and tube formation as well as Matrigel plug angiogenesis. 15(S)‐HETE‐induced Egr‐1 expression requires Src activation. In addition, adenovirus‐mediated expression of dominant negative mutant of Src blocked 15(S)‐HETE's effects on migration and tube formation of HDMVECs and Matrigel plug angiogenesis. 15(S)‐HETE induced FGF‐2 expression rapidly via Src‐mediated production of Egr‐1. Cloning and mutational analysis of FGF‐2 promoter revealed that Egr‐1 binding site proximal to transcription start site is required for 15(S)‐HETE‐induced FGF‐2 expression. Neutralizing antibody‐mediated suppression of FGF‐2 function also attenuated the effects of 15(S)‐HETE on HDMVEC migration and tube formation as well as Matrigel plug angiogenesis. Furthermore, in contrast to WT mice, 12/15‐LOX−/− mice exhibited decreased Matrigel plug angiogenesis in response to AA. Based on these observations, we conclude that 15(S)‐HETE‐induced angiogenesis requires Src‐mediated Egr‐1‐dependent rapid induction of FGF‐2.
Sympathetic Preganglionic Neurons Modulation by Nitric Oxide in The Spinal Cord
Authors: Sabino Joao Paulo J , Bombarda Gabriela , Silva Carlos Alberto Aguiar , Fazan Rubens , Salgado Maria Cristina Oliveira , Salgado Helio Cesar
Published: June 2021

The role played by the nitric oxide/cyclic guanosine monophosphate pathway (NO/cGMP) on sympathetic preganglionic neuron (SPN) modulation still deserves a thorough investigation. Therefore, the role played by NO/cGMP pathway of the spinal cord in the control of mean arterial pressure (MAP) and heart rate (HR) was examined in conscious rats (N= 56) equipped with catheters into the subarachnoid space (intrathecal) and femoral artery. Intrathecal administration of L‐NAME (an inhibitor of NO synthase) caused an increase in MAP but did not affect HR. Intrathecal ODQ (an inhibitor of soluble guanylyl cyclase) did not change MAP and HR. Intrathecal L‐arginine (a precursor of the synthesis of NO) decreased both MAP and HR, while ODQ given before L‐arginine prevented these effects. AP5 (an antagonist of NMDA receptor) did not attenuate the increase in MAP promoted by L‐NAME. Although the hypotensive and bradycardic responses induced by Intrathecal administration of L‐arginine was dependent of cGMP, our results indicate that NO acts as a tonic inhibitory neuromodulator of SPN, independent of either cGMP or NMDA receptors.

Research support: CAPES, CNPQ e FAPESP.
Relationship between birth weight and the autonomic nervous system
Authors: Chiba Haruka , Nagai Mizuki , Haga Mayu , Sasaki Konosuke , Maruyama Ryoko
Published: June 2021

Background

Epidemiological studies have suggested that low or high birth weight is a risk factor for hypertension in later life. Generally, blood pressure is regulated by several factors, including the number of nephrons, hypothalamic pituitary adrenal function, and the autonomic nervous system (ANS). However, the mechanism by which low or high birth weight leads to hypertension has barely been elucidated. To address this lack of research, we studied the relationship between birth weight and ANS.

Purpose

The aim of this study was to investigate the effect of birth weight on heart rate variability (HRV) and cardiovascular responses.

Methods

In nonsmoking, healthy volunteers aged 20 to 30 years, we measured ECG and blood pressure (BP) in the right arm by autonomic sphygmomanometer after stabilization for 5 min throughout the experiment. We allocated participants to a low‐birth‐weight group, normal‐birth‐weight group, and high‐birth‐weight group.

Result

Birth weight was inversely correlated with systolic BP and the ratio of low‐frequency to high‐frequency (LF/HF) power, an index of sympathetic nerve activity. There was a positive relationship between systolic BP and LF/HF.

Conclusion

Low birth weight probably has an influence on autonomic nervous system regulation.
Interactions between purinergic receptors and Kir channels in neurovascular coupling
Authors: Xu Haoliang , Vetri Francesco , Mao Lizhen , Pelligrino Dale A.
Published: June 2021

We previously noted a large overlap in the contributions from adenosine (ADO) and K+‐ channels in the process of neurovascular coupling (NVC), implying the presence of interactive mechanisms. In this study, we assessed whether neural activation‐related pial arteriolar dilation (PAD) involved interactions among A2A receptors, large‐conductance Ca2+‐operated K+ (BKCa) channels, and inward rectifier K+ channels (Kir). In rats with closed cranial windows, we monitored sciatic nerve stimulation (SNS)‐induced PAD in the absence or presence of an A2A blocker (ZM 241385, 10 μM), BKCa blocker (paxilline [PAX], 10 μM), and Kir blocker (BaCl2, 100 μM). Each of these interventions led to a substantial (60–67%) suppression of SNS‐induced PADs, confirming the involvement of A2A receptors and BKCa and Kir channels in NVC. Furthermore, cortical suffusion of ADO, NS1619 and KCl evoked dose‐dependent PADs, which were subsequent blunted (by 56–70%) in the presence of 100 μM BaCl2. On the other hand, the presence of PAX abolished NS1619‐induced PAD, without affecting ADO or KCl‐related PAD. Results suggest that enhancing Kir function via the increased activities of both A2A and BK pathways represents an important mechanism of NVC. We speculate that the Kir‐dependence of the ADO response may involve A2A‐mediated cAMP generation and subsequent phosphorylation‐related potentiation of Kir channel function.
Potential Role of TRPC1 and TRPP2 Channels in Mediating Calcium Signaling Response of Brain Microvessel Endothelial Cells to Mechanically‐Induced Injury
Authors: Berrout Jonathan , Jin Min , O'Neil Roger G
Published: June 2021

Traumatic brain injury can lead to the breakdown of the blood brain barrier (BBB). Since elevation of cytosolic calcium levels, [Ca]i, can compromise the BBB integrity, we assessed the effects of mechanical injury on [Ca]i in brain endothelial cells. Mouse brain microvessel endothelial cells (bEnd3) were grown on elasticized membranes and [Ca]i monitored using Fura 2 fluorescence imaging. Application of a “moderate” injury, using a pressure/stretch pulse of 50 ms (~35% stretch; Cell Injury Controller II module), induced a rapid transient increase in [Ca]i by 129 +/− 27 nM. In the absence of extracellular Ca, the injury‐induced [Ca]i transient was greatly reduced, but not eliminated, implicating both Ca release from intracellular stores and Ca influx across the cell membrane. Unloading of Ca stores by treatment with thapsagargin (10uM) did not abolish the injury transient. Addition of LOE‐908 (10uM) and Amiloride (10uM), TRPC and TRPP2 channel blockers respectively, both reduce the transient [Ca]i increase. In addition, siRNA knockdown assays have implicated the involvement of TRPC1 and TRPP2 in mediating the injury‐induced [Ca]i response. It is concluded that mechanical injury of brain endothelial cells induces calcium influx, implicating [Ca]i transients in injury‐induced barrier breakdown. Further, the induced Ca influx appears to be associated with injury‐induced TRPC1 and TRPP2 channel activation.
Functional expression of P2Y1 purinergic receptors in the coronary circulation
Authors: Bender Shawn B , Berwick Zachary C , Laughlin M. Harold , Tune Johnathan D
Published: June 2021

Accumulating evidence suggests that P2 purinergic receptor activation by ATP and ADP contributes to the control of skeletal muscle blood flow. Whether there is a role for this mechanism in regulating coronary blood flow (CBF), however, remains unclear. We examined the hypothesis that activation of P2Y1 receptors contributes to the regulation of CBF. Specifically, experiments examined the expression and functional role of the P2Y1 receptor both in vivo and in vitro in the canine coronary vasculature. Real‐time PCR demonstrated mRNA expression for P2Y1 receptors in canine coronary vessels. ATP, a nonselective P2 agonist, dose‐dependently increased CBF from 0.4 ± 0.03 to 3.6 ± 0.4 ml/min/g in vivo and dilated isolated coronary arterioles 83 ± 7% in vitro. Selective blockade of P2Y1 receptors with MRS‐2179 reduced maximal ATP dilation to 2.8 ± 0.4 ml/min/g in vivo and by 51% in vitro. Selective activation of P2Y1 receptors with 2MeS‐ADP induced 61 ± 12% dilation in isolated coronary arterioles. P2Y1 receptor blockade had no effect on CBF at rest, in response to changes in coronary pressure (30–100 mmHg) or following a 15 sec coronary artery occlusion. These findings indicate that although P2Y1 receptors are functionally expressed in the coronary microcirculation they do not significantly contribute to pressure‐flow autoregulation or dilation in response to cardiac ischemia. Supported by NIH HL092245 and PO‐1 52490.
Acute glutathione supplementation enhances endothelial‐mediated coronary artery dilation
Authors: Levy Andrew S , Smith Christopher S , Rush James WE
Published: June 2021

Reports from both human and animal studies demonstrate that acute thiol manipulation influences both vascular function and nitric oxide (NO) production. To this end acute glutathione (GSH) administration has been used to enhance coronary vasodilation; however, the mechanisms have not been fully resolved. The purpose of this investigation was to determine how acute GSH administration alters NO‐mediated coronary artery dilation. Endothelial function was assessed in isolated, perfused hearts using a Langendorff apparatus. GSH was administered at concentrations of 0 (CON), 1 or 10 μM and dose‐response curves to bradykinin (BK) were constructed. The sensitivity to BK was enhanced at the 10 μM concentration (p<0.01) and no differences were seen in maximal dilation. In the presence of LNAME (0.1 mM) and/or sGC inhibition (ODQ, 3 μM) the sensitivity to BK remained enhanced in the presence of GSH (10 μM) (p<0.05). Treatment with TEMPOL (0.1 mM) enhanced the sensitivity to BK in CON similar to the effect of GSH (10 μM) and GSH (10 μM)+TEMPOL (0.1 mM). TEMPOL enhanced the sensitivity to exogenous NO (SNP), whereas GSH slightly reduced maximal dilation to SNP. Collectively, these results suggest GSH enhances BK mediated dilation through an antioxidant‐dependent mechanism unrelated to NO production or utilization.

Supported by Heart and Stroke Foundation & Natural Science and Engineering Research Council
Enhanced coronary ET‐1 responsiveness and altered K+ channel Ca2+ sensitivity in aortic‐banded miniature swine is attenuated by aerobic interval training
Authors: Emter Craig A. , Tharp Darla L. , Ivey Jan R. , Bowles Douglas K.
Published: June 2021

Altered responsiveness to mediators of vascular tone is observed in several models of congestive heart failure (HF). Recent evidence indicates exercise training is beneficial for patients with HF but the precise intensity and underlying mechanisms are unknown. The purpose of this study was to examine coronary vascular function (CVF) in aortic‐banded (AB) sedentary (HFSED, n=6), AB exercise trained (HFTR, n=5) and control sedentary (SED, n=5) male Yucatan miniature swine. In vivo coronary blood flow (CBF) responses to intracoronary infusion of ET‐1 (1–20 ng/kg/min) and adenosine (ADO; 0.5–5 ug/kg) were measured in the left anterior descending coronary artery (LAD) under anesthesia. Resting CBF was reduced and coronary vascular resistance (CVR) increased (p<0.05) in HFSED animals. The diminished CBF response to ADO in HFSED was attenuated with exercise training and occurred despite unaltered capillarization. ET‐1 induced reductions in conductance (p≤0.05) and increases in resistance (p=0.056) were greater in HFSED vs. SED and HFTR groups. A shift from 200 to 500 nM internal Ca2+ increased total K+ current (whole‐cell voltage clamp) in HFTR and SED but not HFSED LAD smooth muscle cells. In conclusion, interval exercise training attenuates increased basal CVR in AB miniature swine. Increased in vivo ET‐1 and altered K+ channel Ca2+ sensitivity potentially underlie altered CVF. NIH HL093982 & HL52490
Perfusion Territory of Embolized Coronary Artery Vasa Vasorum
Authors: Moritz Regina , Eaker Diane R. , Anderson Jill L. , Kline Timothy L. , Jorgensen Steven M. , Ritman Erik L.
Published: June 2021

Occlusion of coronary vasa vasorum (VV) leads to hypoperfusion of the arterial vessel wall (AVW) possibly resulting in impaired solute transport. We hypothesize that high cholesterol (HC) facilitates development of atherogenesis in hypoperfused areas.

Swine (40) underwent injection of gold‐coated μspheres (100μm) in left coronary artery. After the procedure 13 swine were studied immediately, 13 were fed a standard (C) and 14 a HC diet for 3 months prior to study. The LADs were harvested and snap‐frozen (cryo micro‐CT scanning). Hypoperfused areas in the AVW were defined by local reduction of CT‐values. The distance of μsphere to lumen (x) was measured, and foam/fat cells/mm2 (f/fc) in hypoperfused and perfused areas were counted using histology.

Linear relationship between x and hypoperfused AVW.

In HC the f/fc # in media of hypoperfused areas is higher than in C (p=0.001).

In HC f/fc # is higher in hypoperfused AVW areas compared to adjacent perfused areas (p<0.05).

In C there is no difference in f/fc # between hypoperfused and perfused areas (p=0.92).

In C and HC the f/fc # in intima of perfused, as well as in hypoperfused, areas is not different (p=0.9/0.5).

Occlusion of VV leads to increased susceptibility of hypoperfused AVW areas for precursors of atherosclerosis with HC diet. The linear relationship of hypoperfused area to μsphere distance suggests that VV function as a plexus rather than a vascular tree.

This study was supported by NIH grant HL065342.
12/15‐LIPOXYGENASE: ROLES IN LARGE AND SMALL FIBER PERIPHERAL DIABETIC NEUROPATHY
Authors: Stavniichuk Roman , Drel Viktor R , Shevalye Hanna , Vareniuk Igor , Nadler Jerry L , Obrosova Irina G
Published: June 2021

Upregulation of 12/15‐lipoxygenase (12/15‐LO), responsible for the formation of 12(S)‐HETE, 15(S)‐HETE and their derivatives from arachidonic acid, causes oxidative stress, MAPK activation, and inflammation. We evaluated the role for 12/15‐LO in peripheral diabetic neuropathy (PDN). Wild‐type (WT) and 12/15‐LO−/− mice were made diabetic with streptozotocin and maintained for 14 wks. 12/15‐LO deficiency did not affect glycemia. Diabetic WT mice displayed increased 12/15‐LO expressions and 12(S)‐HETE levels in sciatic nerve and spinal cord. Thermal hypoalgesia, tactile allodynia, and nerve conduction slowing were clearly manifest in diabetic WT mice, and were prevented or alleviated in diabetic 12/15‐LO−/− mice. Diabetic WT mice displayed reductions in myelinated fiber diameter and myelin thickness, indicative of axonal atrophy of large myelinated fibers, as well as in intraepidermal nerve fiber density (INFD), a sign of small sensory nerve fiber degeneration. 12/15‐LO deficiency prevented diabetes‐induced axonal atrophy, but not a reduction in INFD. In conclusion, the 12/15‐LO mechanism provides an important contribution to peripheral nerve dysfunction and axonal atrophy of large myelinated fibers, whereas its role in small sensory nerve fiber degeneration is minor. The latter should be considered in selection of endpoints for future clinical trials of 12/15‐LO inhibitors.
Akt Plays an Important Role in Lipopolysaccharide‐Induced Myocardial Injury and Protection
Authors: Zhang Yingmei , Ge Wei , Ren Jun
Published: June 2021

Lipopolysaccharide (LPS), an essential component of the outer membrane of Gram‐negative bacteria, plays a pivotal role in the pathogenesis of cardiac dysfunction in endotoxemia. Paradoxically, recent evidence also denoted a protective effect of LPS against ischemia/reperfusion injury via a PI3K/Akt pathway. This study was designed to evaluate the role of Akt in LPS‐induced cardiac dysfunction using a novel model of Akt knockout mice. Echocardiographic and cardiomyocyte function [peak shortening (PS), time‐to‐PS, time‐to‐90% relengthening (TR90)] were examined in C57 (wide‐type) and Akt2−/−mice treated with LPS (4 mg/kg, 4 hrs). Our results revealed that LPS treatment caused increased Akt phosphorylation in wide‐type mice while no change in Akt2−/−mice. Our results also revealed that either Akt2 knockout or LPS reduced fractional shortening (FS), PS and maximal velocity of shortening/relengthening as well as prolonged TR90. Interestingly, the mechanical dysfunctions seen in Akt2−/−mice were significantly improved by LPS. These data collectively suggested that Akt may be a double‐edged sword for endotoxemia‐induced cardiac contractile response.
The effect of physical deconditioning and exercise on VEGF expression and vascular function
Authors: Hopman Maria T.E. , Thijssen Dick H.J. , Horstman Astrid M.H. , de Haan Arnold , Janssen Thomas W.J. , van Duijnhoven Noortje T.L.
Published: June 2021

Vascular endothelial growth factor (VEGF) has been identified as a key growth factor that modulates vascular adaptations. The aim of our study was to assess the impact of physical deconditioning and exercise training on vascular structure and function, and to determine expression of genes involved in the VEGF‐pathway. Six healthy men underwent 3 weeks of Unilateral Lower Limb Suspension (ULLS), while eight men with a spinal cord injury performed an 8‐week Functional Electrical Stimulation (FES) exercise training. Before and after the intervention, vascular characteristics of the superficial femoral artery were measured using ultrasound, and biopsies were taken from the vastus lateralis and soleus muscles. Baseline diameter was decreased after ULLS (P<0.05), and increased after FES training (P<0.01). Flow‐mediated dilation was unaltered after ULLS and FES exercise. VEGFB, VEGF receptor Flt‐1 and co‐receptor NRP‐1 mRNA were downregulated after ULLS (P<0.05), while FES exercise upregulated VEGFB, NRP‐1 and co‐receptor HSPG‐2 mRNA (P<0.05). For the first time, human translational data is available to simultaneously evaluate adaptations in vascular health and VEGF related gene expression to physical deconditioning and exercise. Our study indicates that vascular adaptations do occur parallel to alterations in expression of VEGFB and its (co‐)receptors Flt‐1 and NRP‐1.
Transcriptional regulation of metabolic genes in the postprandial python heart: an extreme example of physiologic adaptation
Authors: Wall Christopher E , Riquelme Cecilia A , Secor Stephen , Leinwand Leslie A
Published: June 2021

In order to cope with the physiologic stresses of digesting large meals, the heart of the Burmese python undergoes significant hypertrophy in as little as 24 hours, returning to the fasted state a few days afterwards. This remarkable response has led us to investigate the molecular mechanisms utilized by python ventricular myocytes during the onset and regression of hypertrophy. We have initially focused on using quantitative PCR to examine changes in the transcripts of genes involved in metabolic processes and cardiac function between fasted and post‐fed states in the heart. We have demonstrated that genes involved in glycolysis and lipid import are downregulated during hypertrophy, while the expression of genes that control lipolytic processes are maintained in response to elevated serum lipid concentrations. Moreover, we have shown that the hypertrophic python heart favors the expression of genes that maintain a highly contractile state, and also exhibits a striking pattern of gene markers that would indicate both physiology and pathology in a mammalian system. These results implicate a novel mechanism of molecular regulation utilized by the python in order to facilitate the dynamic changes inherent to cardiac hypertrophy. This research was supported by a grant from Hiberna, Inc.
Upregulation of β1, β2 and β3 adrenergic receptor expression in the hibernating bear myocardium: A role for cardioprotection?
Authors: Nelson O. Lynne , Robbins Charles T , Bentjen Steve
Published: June 2021

Hibernating grizzly bears demonstrate evidence of low sympathetic nervous system tone but may respond to noxious stimuli. We examined the ability of the hibernating bear to respond to catecholamine administration. Four bears were used to examine the effects of isoproterenol (ISO), on cardiac function during the active and hibernating period by echocardiography. Heart rate (HR), left ventricular (LV) ejection fraction (EF), diastolic filling volume (DV) and cardiac output index (CI) were measured. LV myocardium from 8 active, 8 hibernating bears were used to quantify β1, β2 and β3 AR mRNA expression by rtPCR. HR and LVEF were more sensitive to ISO during hibernation. HR increased by 47% (active) and 230% (hibernation). LVEF and CI were not different during the active period as DV was smaller with tachycardia. During hibernation, LV EF increased by 34% and CI increased by 238% while DV was maintained with tachycardia. Increased expression of β1, β2 and especially β3 ARs were found in hibernating bear LV myocardium. β2 AR activity is thought to be antiapoptotic and may contribute to myocardial protection during hibernation. β3 AR inhibits cardiac contraction and is thought to balance excess β1 stimulation (i.e., heart failure). Taken together, βAR regulation in hibernation may provide for a balanced heart rate, contractile and relaxation responsiveness (increasing CI) without sacrificing diastolic filling (myocardial perfusion).
ACE2 over‐expression regulates oxidative stress gene expression in the brainstem
Authors: Xu Ping , Lazartigues Eric
Published: June 2021

Angiotensin (Ang) I converting enzyme type 2 (ACE2) cleaves Ang II into the vasodilator Ang‐(1–7). We previously reported that ACE2 is expressed in the brain and involved in the prevention of hypertension via regulation of autonomic function. We also showed that ACE2 KO mice have increased levels of reactive oxygen species (ROS) in the brain. To clarify the role of ACE2 in the regulation of ROS levels, we performed an oxidative stress PCR array using brainstems from SA mice, with brain‐specific ACE2 overexpression, and control littermates (NT).

In SA mice, the main ROS‐producing enzyme, NADPH oxidase, subunits genes Nox1 (gp91phox homolog), Nox4, p22phox and p67phox were downregulated by −3.1, −1.6, −13.4 and −11 folds respectively, compared to controls. The NADPH oxidase activator 1 (Noxa1) and the dual oxidase1 (Duox1), which generates hydrogen peroxide, were also decreased by −2.6 and −1 fold, respectively. Anti oxidant stress enzymes like glutathione peroxidase 1, 3, 6, 8 subunits were downregulated by −180, −3, −2.4, −3.1 folds and so were SOD 1 (−1.2 fold) and 3 (−1.8 fold). Moreover, there was a trend to a reduction in lipid peroxidation (Tbars assay) in the brainstem of SA mice. These data show that ACE2 is regulating the expression of multiple genes involved in the formation and removal of ROS in the brainstem, which may contribute to the prevention of hypertension in this model. NIH RR018766 and HL093178
Investigation of the Association of SCN1B with Cardiac Junctional and Ion Channel Proteins at the Intercalated Disc
Authors: Gatt Jessica Lane , Isom Lori L.
Published: June 2021

Voltage‐gated Na+ channels (VGSCs), located in cardiac intercalated discs, are heterotrimeric molecules containing a central, pore‐forming α subunit and two multifunctional β subunits, associated with multiple proteins to ensure rapid, synchronous electrical transduction of action potentials through cardiac myocytes. Mutations in genes encoding VGSC α and β subunits can lead to cardiac arrhythmias, including Long‐QT and Brugada Syndromes.

We propose that VGSC β1, encoded by SCN1B, plays an integral role in forming multimolecular signaling complexes in heart. Our aim was to use the SCN1B null mouse model to investigatec interactions of Nav1.5 with junctional and ion channel proteins that are dependent on β1. This information will provide insight into how SCN1B mutations lead to cardiac arrhythmia. Using co‐immunoprecipitation, we investigated the association of Nav1.5 with Kv4.3, N‐cadherin, and connexin‐43, in solubilized SCN1B null and wildtype heart membranes.

Previous studies showed that β1 associates with Nav1.5, N‐cadherin, and connexin‐43 in transfected cells. The present in vivo results suggest that Nav1.5 and Kv4.3 form a macromolecular complex in wildtype heart. Nav1.5 and N‐cadherin associate in wildtype but not SCN1B null heart, suggesting that β1 is critical for Nav1.5‐N‐cadherin interactions. Nav1.5 and Cx‐43 remain associated in the SCN1B null heart, suggesting this interaction does not depend on β1. Our results suggest that VGSC β1 is an integral molecular adaptor, organizing and linking Nav1.5 complexes to key junctional and ion channel proteins in the intercalated disc.
Consequences of Enhanced CGRP Receptor Signaling on Cardiac Function and Mortality Post‐Myocardial Infarction
Authors: Peotta Veronica A , Weiss Robert M , Zimmerman Kathy A , Lu Yongjun , Russo Andrew F , Abboud Francois M , Chapleau Mark W
Published: June 2021

Calcitonin gene‐related peptide (CGRP) is a powerful vasodilator released from cardiac sensory nerves post‐myocardial infarction (MI). We have shown that ubiquitous overexpression of the CGRP receptor subunit Receptor Activity‐Modifying Protein 1 (RAMP1) enhances CGRP receptor signaling and attenuates angiotensin‐induced hypertension (J Neurosci 2007, Hypertension 2007). We hypothesized that transgenic expression of RAMP1 will improve cardiac function and prolong survival post‐MI. RAMP1 mice (n=28) and littermate controls (n=22) underwent left coronary ligation or sham surgery at 12–15 wks of age. Control mice with MI (15–19 wks post‐surg) exhibited left ventricular (LV) dysfunction (echocardiogram), cardiac hypertrophy, decreased wheel‐running activity (revs/hr) and 50% mortality (Table, *P<.05). RAMP1 mice were not protected post‐MI; LV ejection fraction (LVEF) was reduced, heart weight/body weight (HW/BW, mg/g) was increased, MI size was increased (64±4 vs. 44±3 %), and mortality was increased (67% vs. 50%)(†P<.05 vs. controls). Interestingly, the MI‐induced decrease in wheel‐running was abrogated in RAMP1 mice (Table).

LVEF
HW/BW
Activity

Sham (S) n=10
.76±.03
4.8±0.2
296±79

MI n=7
.49±.06*
6.1±0.3*
127±45*

RAMP1‐S n=8
.70±.03
5.8±0.2
245±121

RAMP1‐MI n=6
.27±.03*†
8.3±0.9*†
392±137†

We conclude: 1) RAMP1 mice are not protected post‐MI, but instead exhibit marked LV dysfunction and increased mortality; and 2) Despite LV dysfunction, wheel‐running activity is preserved post‐MI in RAMP1 mice. Ubiquitous RAMP1 overexpression may lead to deleterious actions of CGRP that compromise cardiac function. Thus, tissue‐selective targeting of RAMP1 may be critical for therapeutic benefit. (AHA‐0855944G, RR017369, HL14388, VA)
The role of TRPM4 in ventricular cardiomyocytes
Authors: Vennekens Rudi , Herijgers Paul , Freichel Marc , Mathar Ilka , Vandermieren Gerry , Nilius Bernd
Published: June 2021

TRPM4 is a Ca2+ activated non‐selective cation channel. Together with TRPM5 it's the only molecular candidate for this class of ion channels to date. Both genes are members of the Transient Receptor Potential (TRP) family of ion channels. We have shown previously, using Trpm4−/− mice, that this channel plays a critical role in setting the membrane potential, and consequently the driving force for Ca2+ entry in mast cells, which determines ultimately the strength of an allergic reaction. The role of CAN channels in excitable cells however is unclear. In this study we tested whether TRPM4 plays a role in cardiac muscle. We used the analysis of pressure‐volume loops to determine contractility properties in vivo. These results were confirmed in isolated papillary muscle. To determine the role of TRPM4 in cardiomyocytes, we used sharp intracellular micro‐electrodes to measure membrane potential in paced LV papillary muscle. We are currently analyzing the consequences of TRPM4 ablation for cellular signaling in isolated cardiomyocytes using the patch clamp technique.
Characterizing the Cardioprotective Phenotype of Brown Norway Rats: Importance of Optimal Ischemia Duration
Authors: Nabbi Raha , Kersten Judy R. , Stowe David F. , Lazar Jozef , Aldakkak Mohammed , Riess Matthias L.
Published: June 2021

The degree of cardiac ischemia‐reperfusion (IR) injury in Brown Norway (BN) and Dahl Salt Sensitive (SS) rats is remarkably different, with BN hearts being more resistant to IR injury than SS [1]. The objective of our study was to determine the role of varying ischemic duration on genome‐dependent cardioprotection in these two inbred rat strains. Langendorff‐prepared hearts from eight week old male BN and SS rats were perfused at constant pressure (90 mmHg) at 37ºC with crystalloid buffer solution. Isovolumetric left ventricular pressure, heart rate and coronary flow were measured before, during and after 25, 30 or 35 min of global no‐flow ischemia, and infarct size was determined at 120 min reperfusion. We found that longer ischemic periods were associated with worse functional recovery and larger infarct size by the end of reperfusion in both strains. However, the genetic background differentially modified this relationship such that optimal distinction between BN and SS strongly depended on ischemia time. These data suggest that differences in IR injury with varying ischemia duration affect the ability to investigate genome‐dependent cardioprotective pathways. Therefore, the choice of an optimal ischemia time [2] plays a crucial role during investigation of myocardial IR injury using this genetic model.
Co‐enzyme Q10 mitigate oxidized LDL‐induced endothelial inflammation: Role of ROS and NF‐κB signaling
Authors: Wu Yun‐Jhen , Tsai Kun‐Ling , Ou Hsiu‐Chung
Published: June 2021

Oxidized low‐density lipoprotein (oxLDL) plays a key role in the generation and progression of atherosclerosis, which is considered as a chronic inflammatory disease. Coenzyme Q10 (CoQ) has long been utilized as a cardioprotective agent in various heart diseases. One of the most important mechanisms by which CoQ exerts cardioprotection is aerobic ATP production as a mobile electron carrier in the mitochondrial electron transfer chain. The ability of CoQ to afford myocardial protection is also attributed to its antioxidant property. The aim of this study was to examine whether CoQ could prevent oxLDL‐induced endothelial inflammation and to explore the potential mechanisms. Primary human umbilical vein endothelial cell cultures (HUVECs) were incubated with CoQ for 2 hours followed by incubated with oxLDL for additional 24 hours. We found that oxLDL‐induced ROS generation, p38 MAPK phosphorylation subsequent activation of nuclear factor κB (NF‐κB) and up‐regulated relative down stream inflammatory cytokines and adhesion molecules and the adherence of monocytic THP‐1 cells to HUVECs. These detrimental effects were ameliorated dose dependently by CoQ (P<0.05). Results from this study may provide insight into a possible molecular mechanism underlying CoQ suppression of the oxLDL‐mediated in endothelial inflammation.
Perception of food insecurity among indigenous Guarani communities in the state of São Paulo, Brazil
Authors: Segall‐Correa Ana Maria , Azevedo Marta Maria , Ferreira Beatriz , Kepple Anne W. , León‐Marin Leticia
Published: June 2021

Indigenous people in Brazil are divided among 270 ethnic groups. Many live with severe food insecurity (FI), and in some, the prevalence of child malnutrition has been estimated to be up to 50%. This study was based on the validation of the Brazilian Food Insecurity Scale (EBIA), adopted from the US HFSSM. Four Guarani communities in São Paulo were visited from 2007 to 2009 with the aim of understanding concepts of FI and hunger experiences to develop a similar FI measurement appropriate for their context. Food habits, health conditions, and food production were assessed via formal and informal interviews and participant observation. A panel of indigenous health experts provided suggestions for the interviews. Perceptions of FI were explored in group interviews with members of one community. FI is characterized by fear of hunger, not having enough food to share with others, dependence on donations, and lack of access to food that reflects their cultural traditions. Universal dimensions of FI, such as worry about having enough food and insufficient quantity and quality of food, were present, and strategies they described using in the face of FI were somehow similar to the rest of the population. However, more studies are needed in other Guarani and indigenous communities to know how transferable these results are to other indigenous groups.

Funded by the National Council for Scientific and Technological Development – Brazil.
Assessing Differences in the Psychometric Characteristics of the Latin American and Caribbean Food Security Scale in Colombia and Mexico
Authors: Quinonez Hugo Melgar , Uribe Martha C Alvarez , Paras Pablo , Perez‐Escamilla Rafael
Published: June 2021

The Latin American Food Security Scale (ELCSA) was applied to nationally representative samples of Colombia and Mexico (n= 13,611 and 1,560, respectively). This study explores differences in psychometric characteristics of ELCSA when applied in two different national settings. Rasch Modeling was used to assess infit and relative item severities for all questions in the scale separately in the countries. Differences in estimated item severities between the Colombian and the Mexican samples were assessed using Differential Item Functioning (DIF) models. The scale presented adequate fitness and most item infit values were within adequate range (0.8–1.2). Most items in ELCSA presented no DIF larger than 0.5 logit units, and only one item showed a DIF larger than 1.0 logit units (“socially unacceptable copying strategies”; DIF=1.22). Besides this item, households in both countries presented similar relative item severities for all other items, following similar patterns of increasing relative item severities with each item in the questionnaire. This research demonstrates that the psychometric properties of ELCSA are similar when applied in two different Latin American countries. The results of this study support the use of the proposed scale as a regional tool, but suggest also the revision of some of the items used in ELCSA for its better adaptation to diverse settings.