bluuebunny/crossref_metadata_2025_split huggingface dataset:
Roles for neutrophils and monocytes in murine cytomegalovirus‐induced microvascular dysfunction (678.16)
Authors: Khoretonenko Mikhail , Leskov Igor , Stokes Karen 
Published: June 2021

One of the first responses of the vasculature to cardiovascular disease (CVD) risk factors, such as hypercholesterolemia (HC), is endothelial dysfunction, characterized by impaired arteriolar dilation and venular inflammation and platelet recruitment. Pathogens have been implicated in CVD, and we have recently shown murine cytomegalovirus (mCMV), also impairs endothelium‐dependent vasodilation. Although mCMV did not significantly increase blood cell recruitment, mCMV extended the first wave of inflammation (neutrophils) due to HC. Here we used spinning disk intravital microscopy to determine the identity of these recruited leukocytes, and light intravital microscopy to determine if these leukocyte subpopulations contributed to arteriolar dysfunction in mCMV‐infected mice on normal diet (ND) or high cholesterol diet (HC). We demonstrated that mCMV shifted populations of adherent leukocytes in microvasculature of HC mice from predominantly neutrophils towards ~1:1 GR‐1+ monocytes:neutrophils. Depletion of neutrophils using an anti‐Ly‐6G Ab restored arteriolar vasodilation in the mCMV‐HC, but not mCMV‐ND mice. It was also effective at abrogating leukocyte and platelet adhesion. Depletion of GR‐1+ cells (neutrophils and monocytes) protected against the arteriolar dysfunction in both mCMV‐ND and mCMV‐HC mice. These results suggest that mCMV causes a phenotypic shift in the inflammatory leukocytes recruited to venules during HC towards a larger monocyte component, although neutrophils remain key players in the arteriolar dysfunction. Furthermore, our data implicate a role for inflammatory GR‐1+ monocytes in the arteriolar dysfunction associated with mCMV infection.Grant Funding Source: Supported by COBRE GM103433‐NIGMS & Malcolm Feist Cardiovascular Research Endowment Fellowship, LSU
NOS uncoupling in oxidative stress‐associated neurogenic hypertension induced by the high fructose diet (682.2)
Authors: Chan Julie , Wu Kay 
Published: June 2021

The reactive oxygen species (ROS) produced from uncoupled nitric oxide synthase (NOS) leads to oxidative stress. In the rostral ventrolateral medulla (RVLM), where sympathetic premotor neurons located, oxidative stress is involved in neural mechanism of hypertension. We investigate in this study the significance of NOS uncoupling in oxidative stress‐associated neurogenic hypertension induced by the high fructose diet (HFD). In normotensive Wistar‐Kyoto rats, oral ingestion of the HFD for 8 weeks resulted in insulin resistance, hyperglycemia, hypertriglyceridemia, sympathoexcitation and hypertension, accompanied by an increase in tissue level of superoxide but a decrease in NO level in the RVLM. Protein expression of the neuronal NOS (nNOS) and protein inhibitor of nNOS (PIN) was increased, but NOS activity and ratio of dimer over monomer of nNOS were decreased. Gene knocking down of PIN in the RVLM by the small interfering RNA (siRNA) or intracisternal infusion of L‐arginine increased NOS activity, maintained tissue NO level and ameliorated the heightened tissue ROS level in the RVLM of the HFD‐fed animals. The same treatments also significantly reduced the high blood pressure and sympathoexcitation induced by the HFD. In addition, intracisternal infusion of ROS scavenger, tempol, notably blunted sympathoexcitation and hypertension but not hyperglycemia induced by the HFD. Together these results indicate that NOS uncoupling because of an increase in PIN activity may contribute to oxidative stress in the RVLM, resulting in sympathoexcitation and neurogenic hypertension induced by the HFD.Grant Funding Source: Supported by NSC102‐2321‐B182A‐003, National Science Council, Taiwan
Obesity related hypertension: an altered downstream regulation of leptin signaling (682.5)
Authors: Lim Kyungjoon 
Published: June 2021

Background: Short term (3weeks) high fat diet (HFD) consumption leads to an increase in blood pressure (BP) and renal sympathetic nerve activity (RSNA) in rabbits. We suggest there is an altered down‐stream sensitivity of leptin in the hypothalamus which involves altered responses to α‐melanocyte stimulating hormone (α‐MSH) and neuropeptide Y (NPY) when rabbits are fed a HFD.Aim: To investigate the role of α‐MSH and NPY in the hypothalamus in HFD‐fed rabbits.Methods: New Zealand White Rabbits were fed with a normal or a 13.3% HFD for 3 weeks. A bilateral guide cannula into the dorsomedial (DMH) or ventromedial hypothalamus (VMH) and an RSNA recording electrode was implanted. After 3 weeks on the diet, α‐MSH (0.1, 0.3nmol), NPY (0.1, 0.5nmol) or Ringer’s were injected directly into the DMH or VMH.Results: Rabbits exhibited higher BP, HR and RSNA when fed a HFD compared to controls (n=6‐8). α‐MSH injection into the DMH increased BP (5.7%, P<0.05 and 8.3%, P<0.01 with 0.1nmol and 0.3nmol respectively) and RSNA (40%, P<0.05 with 0.3nmol) in HFD rabbits. When α‐MSH was injected into the VMH, BP was unchanged but RSNA was increased (28%, P=0.01 and 38%, P<0.01) in HFD rabbits. NPY injection had no effect in both control and HFD rabbits.Conclusion: Elevated blood pressure and sympatho‐excitation in HFD rabbits are due to increased sensitivity of the leptin signalling pathway which involves a dorsal and ventral hypothalamic projection of α‐MSH activated second order neurons.
Kappa opioid receptor therapy post pressure overload induced hypertrophy preserved cardiac function (682.6)
Authors: Zemljic‐Harpf Alice , Deussen Daniel , Vaishnav Yash , Headrick John Headrick , Peart Jason , Niesman Ingrid , Roth David , Patel Hemal 
Published: June 2021

Introduction: The loss of contractility and myocardial function are major aspects of heart failure. Obesity is an independent risk factor for developing hypertensive heart disease. The incidence of heart failure is currently increasing and novel therapeutics are needed. Opioid receptor stimulation is protective against myocardial ischemic‐reperfusion‐injury; whether this protection can be translated to heart failure is unclear. Hypothesizing that stimulation of κ‐opioid receptors preserves cardiac function during left ventricular hypertrophy, we performed the first study of OR‐stimulation in mice exposed to left ventricular pressure overload.Methods: Transverse aortic constriction (TAC) was performed on male, 8‐10 week old, C57Bl/6J mice. Two weeks after TAC, treatment was started with either an irreversible δ‐opioid receptor agonist (ORA) FIT, the selective κ‐ORA U50488H or a vehicle control. Drugs were administered intraperitoneally, FIT (10μg/kg) every 72h and U50488H (1.25mg/kg) daily. Echocardiography was performed before TAC and consecutively at weeks 2, 4, 6, 8 and 10 to determine cardiac function and left ventricular dimensions.Results: The physiological hypertrophic response post TAC was not altered in δ‐ and κ‐ORA treated TAC animals. Heart weight/tibia length ratios were significantly higher in TAC (TAC > 9.74 to Sham < 7.01, p<0.037), with no difference between the three groups. In the vehicle TAC group cardiac function started to diminish from 4 weeks onward. Cardiac function was preserved in TAC mice treated with U50488H, when compared to vehicle TAC. The ejection fraction and fractional shortening were significantly (p<0.04) higher in U50488H group from the six week time point onward, when compared to vehicle TAC and showed no significant difference when compared to U50488H treated Sham group.Conclusions: κ‐ORA (U50488H) stimulation may offer a novel treatment option to preserve heart function in pressure overload induced left ventricular hypertrophy.
The functional changes in the basilar artery due to overpressure blast injury (685.1)
Authors: Toklu Hale , Muller‐Delp Judy , Yang Zhihui , Ghosh Payal , Strang Kevin , Scarpace Philip , Wang Kevin , Tumer Nihal 
Published: June 2021

Overpressure blast‐wave induced brain injury (OBI) leads to progressive pathophysiological changes resulting in a reduction in brain blood flow, blood brain barrier breakdown, edema and ischemia. The aim was to evaluate cerebral vascular function after single and repeated OBI. Male Sprague Dawley rats (250‐300 g) were divided into 3 groups: Control (Naive), single OBI [30 psi peak pressure, 1‐2 msec duration], and repeated (every three days) OBI (r‐OBI). Rats were sacrificed 24 h post injury (8th day) and the basilar artery was cannulised in the pressurized system (90cm H2O). Vascular responses to KCl (30‐50‐100 mM) endothelin (10‐11‐10‐7 M), acetylcholine (ACh) (10‐9‐10‐4 M) and diethylamine (DEA)‐NONO‐ate (10‐9‐10‐4 M) were evaluated.OBI resulted in an increase in the contractile responses to endothelin and a decrease in the relaxant responses to ACh in both single and repeated injury groups. However, impaired DEA‐induced dilation and increased wall thickness to lumen ratio were observed only in the r‐OBI group.These findings indicate that single OBI causes endothelium‐dependent and ‐independent alterations in cerebral vascular function and repeated injury results in increased arterial wall thickness.Grant Funding Source: This work was supported by the Medical Research Service of the Department of Veterans Affairs, McKni
Characterization of a novel transgenic rat model for imaging brain vascular dynamics in vivo using confocal endomicroscopy (686.27)
Authors: Mayorov Dmitry , Roloff Eva , Alenina Natalia , Bader Michael , Teschemacher Anja , Paton Julian , Kasparov Sergey 
Published: June 2021

We evaluated the feasibility of imaging brain vasculature in a transgenic rat model (L7543) which expressed a construct carrying the eGFP under the control of CAG promoter (Popova et al., Transgen. Res. 2008) using fiber endomicroscopy (CellVizio, Mauna Kea Technologies). eGFP expression were first evaluated in cortical and brainstem slices from L7543 rat using confocal microscopy (Leica SP5). Expression of eGFP in the cortex and brainstem was largely restricted to endothelial cells, although astrocytes in younger rats (up to P35) were also fluorescent. Next, the brainstem and cortex were imaged, without a contrasting agent, in anaesthetized P21‐P40 rats using a fiber probe‐based confocal laser endomicroscopy. Pial microvessels of the ventral or dorsal brainstem, or cortex were imaged using S‐1500 and Mini‐Z probes (1.5 and 0.94 mm tip diameter, respectively). The vascular contractility was visualized after application of a thromboxane agonist U46619 and sodium nitroprusside. Arterioles and veins were identified based on the eGFP expression profile. In addition, beveled probes S‐300/B and S‐650/B (0.3 and 0.65 mm tip diameter, respectively) were used to visualize vascular tree in Z‐dimension. Currently we are working to adapt this method for imaging in unanaesthetized rats. This approach should be useful to investigate changes in cerebral microcirculation in hypertension and other vascular pathologies.Grant Funding Source: Supported by British Heart Foundation
Brain‐derived neurotrophic factor overexpression in the paraventricular nucleus increases blood pressure via angiotensin type‐1 receptor‐mediated mechanisms (686.3)
Authors: Erdos Benedek , Backes Iara , Hayward Linda , Sumners Colin , Scheuer Deborah 
Published: June 2021

BDNF expression increases in the PVN during hypertensive stimuli including stress and hyperosmolarity, and we have shown previously that overexpression of BDNF in the PVN leads to significant increases in mean arterial blood pressure (MAP). Here, we tested the hypothesis that BDNF‐induced pressor responses are mediated by angiotensin signaling in the central nervous system. MAP was recorded in male Sprague‐Dawley rats using telemetry. At 11wks of age, adeno‐associated viral vectors (AAV2‐GFP or AAV2‐BDNF) were injected bilaterally into the PVN, and losartan (Los; 15µg/ 0.5µL/ hour) or saline was infused icv for 4 wks using osmotic pumps. During the 4 wks after vector injections, MAP remained unchanged in the GFP+saline (dMAP=2.5±0.4 mmHg) and GFP+Los (dMAP=2.6±1.2 mmHg) groups. MAP increased markedly in both BDNF groups, but the increase was significantly reduced in BDNF+Los (dMAP=15.0±3.2 mmHg) compared with BDNF+saline (dMAP=28.7±2.2 mmHg, p<0.05). RT‐PCR from PVN tissue samples of AAV2‐GFP and AAV2‐BDNF‐injected rats indicated that BDNF significantly upregulated AT1R mRNA (2‐ddCt was 1.1±0.2 in GFP and 2.0±0.4 in BDNF rats using 18s as internal control, p<0.05). In contrast, mRNA levels of angiotensinogen, angiotensin converting enzyme (ACE), ACE2 and AT2R were unaffected by BDNF. We conclude that the BDNF‐induced MAP increase is partially mediated by AT1R, which is upregulated by BDNF within the PVN.Grant Funding Source: Supported by AHA 11SDG7560022, an AFAR research grant, and by NIH #HL76807, #HL93186.
Exercise augments but sinoaortic denervation blocks noradrenergic signaling to PVN in trained normotensive rats (686.5)
Authors: Michelini Lisete , Santos Carla , Ruggeri Adriana , Braga Douglas , Ceroni Alexandre 
Published: June 2021

Exercise training (T) increases ascending NORergic signaling from NTS to PVN, improves baroreflex sensitivity (BrS) and reduces basal heart rate (HR). We evaluate the effects of sinoaortic denervation (SAD) and T on cardiovascular parameters and expression of PVN oxytocinergic (OTergic) and vasopressinergic (VPergic) neurons. SAD and SHAM rats were submitted to low‐intensity T or kept sedentary (S) for 3 month. After hemodynamic measurements, rats were euthanized; perfused brains were post‐fixed and cryoprotected. Sequential PVN slices (30 μm) were processed for OT, VP and dopamine β‐hydroxylase (DBH) immunoreactivity (ir); images were acquired and analyzed by Image J. In SHAM rats T reduced basal HR, increased BrS (328±8 b/min, 2.4±0.2 b/min/mmHg, ‐13% and +25% vs S controls), augmented the density of DBH terminals and OTir in ventromedial PVN and reduced VPir in the magnocelular PVN, without changing DBH signaling to this area. SAD markedly reduced basal OTir and VPir in both PVN areas and blocked functional and T‐induced effects on OTir and VPir. T‐induced afferent signaling, directed preferentially to preautonomic areas, increases the expression of OTergic neurons, contributing to the appearance of beneficial effects in intact T rats. SAD blocks these effects confirming that PVN signaling conveyed by baro‐ and chemoreceptors is essential to maintain neuronal tonicity and to mediate T‐induced effectsGrant Funding Source: Supported by FAPESP, CNPq
Anti‐inflammatory effects of Hedyotis diffusain ob/ob mice (688.2)
Authors: Kang Min‐Jung , Kim Jung‐In , Yim Jung‐Eun 
Published: June 2021

Non‐alcoholic fatty liver disease (NAFLD) is the most common liver disease and is associated with insulin resistance, oxidative stress, and inflammation. Insulin resistance might play an important role in the pathogenesis of NAFLD. Proinflammatory cytokines are thought to be associated with the development of insulin resistance. It has been reported that Hedyotis diffusa was effective at improving insulin resistance and fatty liver in an animal model. This study investigated the anti‐inflammatory effects of Hedyotis diffusa in leptin‐deficient ob/ob mice. Five week‐old ob/ob mice (C57BL/6J, n=16) were fed AIN‐93G diet or diet containing 1% fermented alcohol extract of Hedyotis diffusa for 8 weeks. The serum TNF‐α, IL‐6, and monocyte chemotactic protein‐1 (MCP‐1) levels were measured using enzyme‐linked immunosorbent assay (ELISA) kits. Body weight and food intake of the Hedyotis diffusa group were not significantly different from those of the control group. The serum TNF‐α level of the Hedyotis diffusa group was significantly lower than in the control group. Hedyotis diffusa extract supplementation reduced the serum IL‐6, as compared to the control group. The serum MCP‐1 levels were significantly reduced by the consumption of Hedyotis diffusa extract. Therefore, Hedyotis diffusa could be beneficial for alleviating NAFLD by reducing inflammation.Grant Funding Source: This research was supported by NRF in Korea (20100011980)
Effect of vitamin D3 supplementation on thyroid hormones and deiodinase 2 expression in streptozotocin‐induced diabetic rats (688.9)
Authors: Alrefaie Zienab 
Published: June 2021

Aim: The present study aimed to assess the effect of vitamin D3 administration on deiodinase 2 (D2) mRNA expression in various tissues of diabetic rats.Methods: Thirty male Wistar rats (200‐250 g) were included into; control, diabetic and diabetic supplemented with vitamin D3 groups. Diabetes was induced by single intraperitoneal injection of streptozotocin 45 mg/kg. Vitamin D3 was administered orally in a dose of 500 IU/kg/day in olive oil for 10 weeks. Serum levels of free T4, free T3 and TSH were measured. Tissue homogenates from liver, kidney, muscle, femur bone, heart and brain were obtained and assessed for expression of D2 mRNA.Results: Diabetic rats demonstrated significant increase in free T4 and significant decrease in free T3 with non significant increase in TSH compared to control rats. The changes in thyroid profile were ameliorated by vitamin D3 administration to diabetic rats. D2 mRNA expression was significantly reduced in all tissue homogenates of diabetic rats, however vitamin D3 did enhance D2 mRNA expression especially in liver and brain of diabetic rats.Conclusion: Diabetes mellitus inhibited peripheral conversion of T4 into T3 secondary to reduction in the expression of D2 in almost all body tissues. Vitamin D3 greatly corrected the alterations in thyroid profile and D2 expression in diabetic rats and protected against the subclinical hypothyroid state that could associate diabetes mellitus.Grant Funding Source: No
Isoform‐specific interactions between meprin metalloproteases and the catalytic subunit of protein kinase A (690.13)
Authors: Niyitegeka Jean‐Marie , Bastidas Adam , Newman Robert , Taylor Susan , Bond Judith , Ongeri Elimelda 
Published: June 2021

Meprin metalloproteases are abundantly expressed in the brush border membranes of kidney proximal tubules. Meprins are also expressed in podocytes, skin, and leukocytes. Meprins have been implicated in the pathology of acute and chronic kidney injury. To understand how meprins impact kidney disease, it is important to characterize interactions between meprins and their substrates. This study evaluated isoform‐specific interactions between the catalytic subunit of protein kinase A (PKA C) and meprins. Kidney proteins from meprin αβ double knockout mice, as well as purified recombinant mouse PKA Cα, Cβ1, and Cβ2, were incubated with activated forms of either meprin A (α‐α) or meprin B (β‐β). Cleavage products were analyzed by Coomassie staining or Western blot analysis. To identify meprin cleavage sites on PKA C isoforms, full length PKA C and meprin cleaved fragments were trypsin digested, separated by C18 nanoflow liquid chromatography‐MALDI, and analyzed by ProteinPilot. To characterize the kinetics of meprin B cleavage of PKA Cα, the Km and kcat were determined using Michaelis‐Menten enzyme kinetics. Meprin A only cleaved PKA Cβ1 while meprin B cleaved all three PKA C isoforms. Moreover, meprin cleavage of PKA Cα and Cβ2 significantly decreased their kinase activity, suggesting that the impact of meprins on kidney injury may be due, in part, to modulation of PKA signaling pathways.Grant Funding Source: Supported by NIH grants SC3GM102049, GM19301, GM19301, F31GM099415, and DK19691
Gelsolin expression modulates TGF‐beta induced cell differentiation and epithelial to mesenchymal transition in breast cancer cells (694.3)
Authors: Liou Ying‐Ming , Chen Zhi‐Yuan , Shieh Dar‐Bin , Chiu Kung‐Ying 
Published: June 2021

Gelsolin (GSN) is one of actin filament‐severing proteins that play a key role in the actin cytoskeleton rearrangement and the modification of tumor cell proliferation and metastasis. TGF‐beta has been shown to initiate the Epithelial to Mesenchymal Transition (EMT) in breast cancer cells. However, the relationship between the expression level of GSN and the TGF‐beta signaling for cell differentiation and EMT progression is not clear. In this study, MDA‐MB‐231 human breast cancer cells were treated with 2 ng/ml TGF‐beta1 for 3 days, and the population of CD44+/CD24‐ cells were sorted out by flow cytometry. These cells were found to increase the gene markers for stem cell pluripotency (i.e. Oct4, Sox2 and Nanog), associated with increased expression for mesenchymal cell markers such as N‐cadherin, and vimentin, and with a concomitant decrease for epithelial marker such as E‐cadherin. In addition, TGF‐beta1 induced an increased gene expression for GSN but decreased expressions for the two DNA methyltransferases, DNMT1and DNMT3B. Methylation specific PCR analysis also showed that TGF‐beta1 caused a 50% decrease in methylation with concomitant 3‐fold increases in unmethylation on the CpG island at the GSN promotor in the CD44+ cells. These results indicated that TGF‐beta1 induced epigenetic modification of GSN might be responsible for the cancer stem cell signaling in breast cancer cells.Grant Funding Source: Supported by NSC 102‐2320‐B‐005‐002
The effect of doxorubicin accumulation on interstitial nitric oxide production in the rat skeletal muscle (698.8)
Authors: Fabris Sergio , MacLean David 
Published: June 2021

The purpose of the present study was to examine the effect of DOX accumulation on interstitial nitric oxide (NO) following the administration of 1.5 or 4.5 mg/kg DOX after 24, 48, 72, 96, 120, 144, 168 and 192 hrs. Interstitial dialysate samples of anaesthetized rats (n=3 control, n=6 treatment) were collected via microdialysis probes (n=4 per rat) and analyzed. Following the 1.5 mg/kg dose, NO increased (P<0.05) after 24 (5.48±0.33 µM), 48 (7.06±0.17 µM), 72 (5.17±0.2 µM), 96 (10.11±0.62 µM), 120 hrs (6.77±0.26 µM) and decreased (P<0.05) at 168 hrs (1.69±0.2 µM) compared to control (2.94±0.36 µM). A dose of 4.5 mg/kg increased NO (P<0.05) after 24 (4.8±0.2 µM), 48 (4.44±0.27 µM), 96 (9.69±1.06 µM), 168 (3.95±0.2 µM) and 192 hrs (4.13±0.16 µM) compared to control. Interestingly NO was decreased (P<0.05) with the 4.5 mg/kg dose after 48 and 120 hrs compared to the 1.5 mg/kg, though NO increased (P<0.05) after 168 and 192 hrs compared to the 1.5 mg/kg dose. These data demonstrate for the first time that DOX accumulation in the SM increases interstitial NO and this increase is dependent on the administered dose, suggesting that DOX administration stimulates interstitial NO production.Grant Funding Source: Supported by NSERC
Directional dependent stretch‐induced response in neonatal mouse cardiomyocytes (699.3)
Authors: Buchholz Kyle , Zambon Alexander , McCulloch Andrew , Omens Jeffrey 
Published: June 2021

Static, mechanical stretch of neonatal cardiomyocytes induces changes in gene expression and can be used as a model to study cardiac hypertrophy. It has been hypothesized that the location of mechanosensors in relation to the cytoskeletal alignment may cause a directionally dependent response.To investigate the directionally‐dependent cellular response to stretch, neonatal mouse cardiomyocytes are cultured on a deformable silicone membrane, which is micropatterned to create parallel grooves that align the cardiomyocytes. By adjusting the groove orientation, the primary direction of stretch can be applied along or transverse to the cell alignment.RNA sequencing (RNA‐Seq) results show a more robust gene response to longitudinal than to transverse stretch. After 30 minutes of stretch, 349 and 1161 genes are considered differentially expressed (DE) from transverse and longitudinal stretch, respectively. After 4 hours, the number of DE genes increases to 962 and 3925. Pathway enrichment analysis indicates that MAPK signaling pathways are induced by both directions of stretch; whereas only longitudinal stretch induces PI3K/Akt signaling. These gene expression and signaling results provide evidence that cardiomyocytes vary in their response to stretch direction and will help identify the mechanosensors responsible for transducing the two modes of stretch.Grant Funding Source: 5P01HL46345