bluuebunny/crossref_metadata_2025_split huggingface dataset:
DCD Donor Heart Pathophysiology and Preconditioning
Authors: Kearns Mark J , Cheung Anson , Bashir Jamil , Seidman Michael A , Boyd John H 
Published: November 2023

PurposeOrgan donation after circulatory death (DCD) is increasingly proposed as a means of addressing organ supply/demand mismatch in cardiac transplantation. We previously demonstrated in a rat DCD protocol that there is no detectable myocardial necrosis in DCD hearts up to a warm ischemic time (WIT) of 16 minutes, but that left ventricular function is impaired. Furthermore, we identified several discriminatory biomarkers in DCD hearts in response to ischemia and reperfusion. The goal of the present study is to investigate the impact of increasing WIT doses, and the ability of a preconditioning agent (CpG, a toll‐like receptor 9 agonist) to mitigate injury in DCD hearts.MethodsDCD hearts exposed to 5, 10, and 20 minutes of acirculatory arrest (with and without pre‐withdrawal CpG administration), beating heart controls, and positive ischemic controls were studied in rats. Left ventricular (LV) functional analyses were conducted in a normothermic, volume‐loaded mode using an ex‐vivo heart perfusion (EVHP) rig. Blinded histologic assessment was performed on trichrome‐stained LV cross‐sections. The relative expression of 4 mRNA transcripts (Myc, Jun, HMOX1, and HSP90aa1) was determined by QPCR in each group.ResultsDCD hearts demonstrated LV functional impairment, which increased with WIT dose. Short WITs weren't associated with irreversible injury, whereas longer WITs (e.g. 20min) were. An aggregate score using donor physiology correlated with the extent of LV dysfunction on EVHP. Furthermore, 4 mRNA biomarkers demonstrated expression profiles that correlated with structural injury and LV dysfunction across WIT groups. CpG oligonucleotides mitigated both functional and structural injury in DCD hearts compared with untreated groups.ConclusionsDCD hearts exposed to short WITs incur functional impairment that is likely reversible, but the extent irreversibility increases with WIT dose. Donor withdrawal variables and mRNA biomarkers were helpful in predicting reversibility of cardiac injury. Critically, a simple pharmacologic agent (CpG) mitigated the degree of structural and functional injury in DCD hearts. This information will improve our ability to accurately determine clinical cutoffs for graft viability. Furthermore, our preconditioning approach raises the possibility of mitigating DCD‐related cardiac injury both prior to donor withdrawal and as a component of machine reperfusion ex‐vivo.Support or Funding InformationMark J. Kearns is supported by a CIHR Frederick Banting and Charles Best Doctoral Research Award, and a Heart & Stroke Robert Hayden Research Fellowship.
Effect of aging on the CO2 reactivity and blowout time in ocular vessels
Authors: Miyaji Akane , Ikemura Tsukasa , Hayashi Naoyuki 
Published: November 2023

Ocular vessels are sensitive to changes in the partial pressure of arterial CO2 (PaCO2). It is well known that the resting blood flow in the ophthalmic artery decreases with age. However, no previous studies have investigated the existence of an age‐related change in the ocular CO2 reactivity; that is, the relative response of the blood flow to a given increase in PaCO2. It has been reported that a possible age‐related decline in the cerebral CO2 reactivity could be associated with vascular function including the blood supply and vessel stiffness, whereas the presence of an age‐related change in the cerebral CO2 reactivity is controversial. The objective of this study was to determine whether the CO2 reactivity in ocular and cerebral vessels changes with aging, and whether there is a relationship between the CO2 reactivity and vascular function in these vessels. We compared the CO2 reactivity responses in the middle cerebral artery (MCA) and optic nerve head (ONH) to a 3‐min inhalation of CO2‐rich air (5%) between 14 young (age 23±0 yr, mean±SD) and 11 middle‐aged (age 48±2 yr) healthy subjects. We examined the relationship in these vessels between the CO2 reactivity and blowout time (BOT), which is an index for assessing the ocular vascular function calculated from flow velocity waveform analysis and is reportedly correlated with aging. The CO2 reactivity in the ONH was significantly greater in the young group (1.0±0.1%/mmHg) than the middle‐aged group (0.6±0.1%/mmHg), but it did not differ in the MCA between the two groups (2.2±0.2%/mmHg and 2.7±0.4%/mmHg, respectively). In the ONH there was no correlation between the CO2 reactivity and BOT, while the CO2 reactivity and BOT were both significantly correlated with age (r=−0.45, p<0.05, and r=−0.54, p<0.05, respectively). In the MCA the BOT was not correlated with either age or CO2 reactivity. These results suggest that there are regional differences in the effect of aging on the CO2 reactivity, and that this reactivity is independent of the vascular function.Support or Funding InformationJSPS KAKENHI grants: number 15J11556 to A.M. and number 26560396 to N.H.
Endothelin‐1 Receptor Responses during the Menstrual Cycle
Authors: Sebzda Kelly N , Wenner Megan M 
Published: November 2023

Endothelin‐1 (ET‐1) is involved in regulating vascular function through two receptor subtypes: endothelin A (ET‐A) and endothelin B (ET‐B). Studies in animal and cell models suggest that ovarian hormones, such as estradiol (E2) and progesterone (P4), modulate differences in ET‐1 mediated vasomotor function. However, these mechanisms have not been comprehensively examined in humans. Therefore, the purpose of this study was to test the hypothesis that ovarian hormones would mediate microvascular vasodilation through an ET‐B receptor mechanism. We measured microvascular vasodilatory responses (% CVCmax) during local skin warming via laser Doppler flowmetry coupled with intradermal microdialysis perfusions of lactated Ringers (control), ET‐B (BQ‐788, 300nM), and ET‐A (BQ‐123, 500nM) receptor antagonists in ten young women (21±1 years, 23±1 kg/m2, 85±2 mmHg resting mean blood pressure) during the mid‐luteal (ML; days 20–25) and early follicular (EF; days 2–6) phases of the menstrual cycle. As expected, serum E2 (ML: 132.9±19.7 vs. EF: 51.1±10.6 pg/ml, P < 0.05) and P4 (ML: 6.8±1.5 vs. EF: 0.9±0.2 ng/ml, P < 0.05) levels were higher in women during the ML compared to the EF visit. ET‐B receptor blockade decreased vasodilatory responses during the ML phase (control: 91.0±1.9 vs. BQ‐788: 84.4±2.1% CVCmax, P < 0.05) but not during the EF phase (control: 88.5±2.4 vs. BQ‐788: 88.9±1.2% CVCmax, P = 0.88). ET‐A receptor blockade tended to decreased vasodilatory responses during the ML phase (control: 91.0±1.9 vs. BQ‐123: 87.7±1.8% CVCmax, P = 0.09) but not during the EF phase (control: 88.5±2.4 vs. BQ‐123: 92.2±2.4% CVCmax, P = 0.20). These data suggest that ET‐B receptors mediate vasodilation during the ML phase of the menstrual cycle, when both E2 and P4 are elevated. Additional studies are needed to determine the direct influence of E2 and P4 on ET‐B receptor function.Support or Funding InformationSupported by NIH Grant U54 GM 104941 01A1 and University of Delaware Research Foundation
Low‐dose Aspirin During Gestation Promotes Vascular Dysfunction and Does Not Ameliorate Maternal Hypertension in Rats Exposed to Innate Immune System Activation
Authors: Jaini Paresh Atu , Nguyen An , Valdes Melissa , Osikoya Oluwatobiloba , Goulopoulou Styliani 
Published: November 2023

BackgroundDaily low‐dose aspirin after 12 weeks of gestation is recommended as a preventive intervention for women at high risk for preeclampsia, a hypertensive disorder of pregnancy with high rates of maternal and fetal mortality and morbidity. Activation of the innate immune system during pregnancy is implicated in the development of preeclampsia. Maternal exposure to synthetic CpG oligonucleotides (CpG ODN, specific ligand of the innate immune receptor Toll‐like receptor 9) induces maternal hypertension, vascular dysfunction, and upregulation of cyclooxygenase enzymes in pregnant rats.HypothesisWe hypothesized that maternal treatment with low‐dose aspirin during gestation would ameliorate TLR9‐induced hypertension and vascular dysfunction in pregnant rats.MethodsPregnant Sprague‐Dawley rats were treated with a synthetic CpG ODN (ODN2395) or vehicle on gestational day (GD) 14, 16, and 18. Aspirin treatment (or control) started on GD10 and continued throughout gestation for all groups [control (no treatment), ODN2395 (300 μg), aspirin (1.5 mg/kgBW), aspirin+ODN2395]. Blood pressure was measured on GD19 using the tail cuff method and mesenteric resistance artery (MES) function was assessed on GD21 using wire myography.ResultsODN2395‐treated rats had higher blood pressure on GD19 compared to vehicle‐treated dams and aspirin did not ameliorate ODN2395‐induced hypertension (control: 97 ± 0.4 mmHg, ODN2395: 121 ± 7 mmHg, aspirin: 101 ± 5 mmHg, aspirin+ODN2395: 121 ± 7 mmHg, p<0.05). Aspirin treatment increased MES sensitivity to PE (pEC50, ODN2395: 5.6 ± 0.1 vs. aspirin+ODN2395: 5.9 ± 0.1, p<0.05) and reduced sensitivity to acetylcholine (ACh) in ODN2395‐treated rats (pEC50, ODN2395: 7.6 ± 0.1 vs. aspirin+ODN2395: 7.0 ± 0.1, p<0.05). Fetal and placental weights did not change in response to any treatment.ConclusionTreatment with low‐dose aspirin throughout gestation did not prevent the development of TLR9‐induced maternal hypertension, augmented vascular sensitivity to α1‐adrenergic receptor activation, and attenuated endothelium‐dependent dilation in rats exposed to innate immune system activation. The use of aspirin during gestation should be considered with caution in clinical cases associated with innate immune system‐induced pregnancy complications.Support or Funding InformationAmerican Heart Association, University of North Texas Health Science Center, Texas College of Osteopathic Medicine Summer Research Fellowship
Sexual dimorphism in mesenteric arterial function of a novel rat model of type 2 diabetes, UC Davis‐Type 2 Diabetes Mellitus (UCD‐T2DM)
Authors: Shaligram Sonali , Akther Farjana , Karimi Mujibullah D , Graham James L , Stanhope Kimber J , Havel Peter , Rahimian Roshanak 
Published: November 2023

This is the first study to characterize the vascular functions in a well characterized and validated polygenic rat model of type 2 diabetes (UC Davis‐Type 2 Diabetes Mellitus, UCD‐T2DM), exhibiting etiology more similar to clinical T2DM in humans than other rodent models. The objectives of this study were to investigate whether 1) the endothelium‐dependent and ‐independent vasodilation in mesenteric arteries (MA) are impaired, 2) sex differences exist in the development of abnormal vascular responses, and 3) the relative contributions of endothelium derived relaxing factors in modulating vascular reactivity of MA is altered in UCD‐T2DM Rats.Endothelium‐dependent vasodilation to acetylcholine (ACh, 10−8 to 10−5 M) in pre‐contracted arteries with phenylephrine (PE, 2 μM) was measured before and after pre‐treatment with indomethacin (cyclooxygenase inhibitor, 10 μM), L‐NAME (nitric oxide synthase inhibitor, 200 μM), or barium chloride (KIR blocker, 100 μM) plus ouabain (Na+‐K+‐ATPase inhibitor, 10 μM). Vascular responses to sodium nitroprusside (SNP) (endothelium‐independent vasodilator, 10−9 to 10−5 M) and contractile agents such as PE (10−7 to 3×10−5 M) or endothelin‐1 (ET‐1, 10−10 to 10−7 M) were also determined.Both ACh‐ and SNP‐induced relaxation were significantly impaired in MA of diabetic rats, regardless of sex. However, the extent of impairment was greater in female diabetic rats compared to male diabetic animals. Diabetes also significantly increased sensitivity to PE or ET‐1 in females compared to males. Finally, the relative importance of endothelium‐derived hyperpolarizing factor (EDHF) to vascular regulation was lost in diabetic rats, regardless of sex.These data, for the first time, show that the endothelial function in MA of UCD‐T2DM Rats is impaired in both sexes, possibly due to the loss of EDHF, initially a major vasodilatory factor. Furthermore, we showed a greater predisposition of MA to injury in diabetic female rats, in part due to a higher sensitivity of female arteries to contractile agents.
Sex Differences in the Gene Expression Profile of LOX‐1 in Mouse Tissues
Authors: Kim Seong Chul , Hamblin Milton H. 
Published: November 2023

Lectin‐like oxidized low‐density lipoprotein receptor‐1 (LOX‐1) is recognized as an important cardiovascular cell scavenger receptor for oxidized low‐density lipoproteins (oxLDL). LOX‐1 activation mediates several oxLDL‐stimulated intracellular signaling pathways and tissue processes that lead to oxidative stress, inflammatory cell infiltration in the vessel wall, endothelial dysfunction, and cardiovascular pathophysiology. In the current study, we analyzed the gene expression profiles of LOX‐1 in the aortas, hearts, liver, lungs, and kidneys of male and female C57BL/6J mice. Significant sex differences were observed in LOX‐1 mRNA expression. LOX‐1 mRNA levels were higher in male mouse aortas and hearts compared with female tissues. Conversely, LOX‐1 gene expression was elevated in female versus male kidneys. In mouse liver and lungs, we found LOX‐1 mRNA levels were comparable in males and females. These results clearly suggest that significant sex differences exist in the gene expression profiles of LOX‐1 in mouse tissues, and given the data supporting the tissue‐specific differences in LOX‐1 gene expression between males and females, we speculate these studies will provide new insights into the cellular mechanisms directly responsible for the critical, sex‐linked roles of LOX‐1 in both vascular dysfunction and other disease complications.Support or Funding Information(Supported by 5K12HD043451).
Components of the Innate Immune System Induce an Increase in Mitochondrial Membrane Potential, Reactive Oxygen Species and Necrotic Cells in Renal Medulla
Authors: Robertson Kirsti , Wildman Scott , Peppiatt‐Wildman Claire 
Published: November 2023

The innate immune system is thought to play a role in the pathogenesis of kidney diseases, such as acute kidney injury (AKI), and yet the precise mechanisms involved are unknown [1]. Mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS) and necrosis are thought to be involved in the injury process of AKI [2] and dysregulation of pericyte function has been associated with ischemic injury, AKI and progression to chronic kidney disease [3].Here we use a rat live kidney slice model [4] in combination with multiphoton microscopy, to investigate whether various components of the innate immune system alter ΔΨm and/or induce production of mitochondrial ROS and cell death in the renal medulla, to assess their effect on cell function. Kidney slices were loaded with the appropriate fluorescent dye; tetramethylrhodamine methyl ester (TMRM), mitoSOX and propidium iodide (PI), respectively. Tissue was then superfused with complement component 5a (C5a), interleukin‐33 (IL‐33) and tumour necrosis factor alpha (TNF‐α), and changes in fluorescent signal were recorded via imaging techniques.C5a evoked a significant increase (34.73% ± 4.56%, 40.87% ± 8.34%, 34.40% ± 7.12%) in TMRM signal in endothelial (E), pericyte (P) and tubule cells (T), respectively, indicating membrane hyperpolarisation. Similar increases in TMRM signal were measured in response to IL‐33 (E: 26.25% ± 2.68%, P: 29.27% ± 8.82, T: 20.79% ± 2.61%) and TNF‐α (E: 44.72% ± 3.72%, P: 52.64% ± 4.29%, T: 54.75% ± 6.14%). C5a also evoked an increase (24.96% ± 5.87%, 31.41% ± 7.70%, 50.14% ± 7.69%) in mitoSOX signal in E, P and T cells, respectively, indicating an increase in mitochondrial ROS, associated with membrane hyperpolarization. Both C5a and TNF‐α evoked increases in mitoSOX fluorescence (E: 44.59% ± 8.59%, P: 30.92% ± 9.07%, T: 26.25% ± 3.37% and E: 61.10% ± 9.72%, P: 51.51% ± 12.08%, T: 70.41% ± 9.25% respectively). Furthermore, C5a also evoked a significant increase (22.74% ± 4.80%) in propidium iodide fluorescent cells across the tissue slice, as did C5a (15.58% ± 3.81%) and TNF‐α (17.02% ± 4.78%) when compared to PSS control experiments (1.58% ± 0.35%), indicating an increase in necrotic cells.We conclude that the innate immune system components C5a, IL‐33 and TNF‐α act at medullary endothelial, pericyte and tubule cells causing membrane hyperpolarisation, and increases in mitochondrial ROS resulting in an increase in necrotic cells. These initial observations provide preliminary evidence that suggests C5a, IL‐33 and TNF‐α may mediate some of the pathophysiological changes thought to underlie AKI.Support or Funding InformationKidney Research UK
Prostamide‐Mediated Protective Action of Anandamide on Nlrp3 Inflammasome Activation in Glomeruli of Mice with Hyperhomocysteinemia
Authors: Xia Min , Li Guangbi , Conley Sabena M , Meng Nan , Boini Krishna M , Ritter Joseph K , Li Pin‐Lan 
Published: November 2023

Recent studies have shown anandamide (AEA), endogenous cannabinoids, and its major renal cyclooxygenase‐2 (Cox‐2) metabolite, prostamide E2 (PGE2‐EA), attenuate Hcys‐induced Nlrp3 inflammasome activation and injury in podocytes. The present study was designed to further test whether in vivo treatment of AEA suppresses Nlrp3 inflammasome activation and thereby prevents glomerular injury in mice with hHcys. Uninephrectomized C57BL/6J wild type mice were fed either normal chow (ND) or a folate free (FF) diet for 4 weeks to produce hHcys. By confocal microscopy we demonstrated that hHcys increased the colocalization of inflammasome proteins Nlrp3 with ASC or with caspase‐1 in glomeruli compared to them in ND fed mice. Correspondingly, IL‐1β production in these glomeruli of mice with hHcys was markedly increased. In vivo administration of AEA substantially inhibited Nlrp3 inflammasome formation and IL‐1β increases in glomeruli of hHcys mice. However, if these mice received Cox‐2 inhibitor, celecoxib, the inhibitory effect of AEA on Nlrp3 inflammasome activation was significantly reduced in glomeruli of mice with hHcys. Correspondingly, hHcys‐induced decrease in podocin and increase of desmin in glomeruli were also reversed by treatment of AEA. Proteinuria and glomerular sclerotic alterations as shown by increases in glomerular damage index (GDI) in mice with hHcys were also attenuated by AEA (GDI decreased from 1.5 in FF mice back to 0.5 in AEA treated hHcys mice). Although celecoxib itself had no effect on hHcys‐induced podocyte dysfunction and glomerular injury, it blocked the protective action of AEA. In Nlrp3 KO mice, hHcys failed to induce Nlrp3 inflammasome activation and glomerular injury and AEA also had no effect on glomerular inflammasomes and glomerular injury in these mice. From these results, we conclude that AEA protects glomeruli from hHcys‐induced Nlrp3 inflammasome activation and consequent glomerular injury through its metabolites such as prostamides via Cox‐2 pathway.Support or Funding InformationSupported by NIH grants HL057244, HL075316, HL091464 and HL122937
Adiponectin Protects Mouse Podocytes from Acid Ceramidase Inhibition‐Induced Injury
Authors: Koka Saisudha , Xia Min , Conley Sabena M , Gehr Todd W , Li Ningjun , Li Pin‐Lan , Boini Krishna M 
Published: November 2023

Our recent studies have demonstrated that acid ceramidase (AC) contributes to the regulation of podocyte function and that the defect of AC gene expression triggers podocyte injury ultimately resulting in obesity‐associated end‐stage renal disease. However, it remains unknown how the inhibition of AC leads to podocyte dysfunction and injury. The current study addressed whether adipokine, adiponectin antagonizes AC inhibition‐induced damage in cultured mouse podocytes. Western blot analysis showed that adiponectin treatment dose dependently increased the acid ceramidase expression in podocytes. Confocal and RT‐PCR analyses showed that AC inhibitor, D‐NMAPPD decreased the podocin expression compared to control cells. However, prior treatment with adiponectin attenuated the D‐NMAPPD‐induced podocin decrease. Furthermore, adiponectin treatment was found to preserve podocyte morphology by maintaining the distinct arrangement of F‐actin fibers normally lost in response to D‐NMAPPD. It also prevented podocyte dysfunction by restoring D‐NMAPD‐induced suppression of VEGF production and secretion. By electromagnetic spin resonance, AC inhibitor was shown to increase superoxide production 1.8 folds compared to control podocytes, which was inhibited by adiponectin. Functionally, AC inhibitor, D‐NMAPPD treatment significantly increased the cell permeability in podocytes compared to control cells (Control: 1 ± 0.1 vs. D‐NMAPPD: 1.6 ± 0.1), and adiponectin attenuated the D‐NMAPPD‐induced increases in cell permeability. In conclusion, our observations suggest that adiponectin may exert an antagonistic action on acid ceramidase inhibition‐induced podocyte dysfunction and injury.Support or Funding InformationSupported by NIH grants DK104031 and DK54927.
Visualizing Regional Kidney Blood Flow in the Mouse
Authors: Cabrales Pedro , Jani Vivek , Hu Vincent J 
Published: November 2023

A study of the perfusion and circulation of blood in large organs is an important interest in study for analyzing effects of various physiological conditions on organ function. The spatial distribution of blood flow in the kidney is a phenotype of interest, because derangements in blood flow may precede detectable changes in organ function. However, quantifying the regional distribution of blood flow within organs of mice is challenging because of the small organ volume and the high resolution required to observe spatial differences in flow. Traditional microsphere methods in which the numbers of microspheres per region are indirectly estimated from counts or extracted fluorescence are limited to whole organ. In order to study perfusion, a traditional microsphere method of analysis was modified to obtain spatial and temporal resolution. 15‐μm fluorescent microspheres were administered via cardiac puncture at different time points. Then, the kidneys divided in three regions: two medullar regions and one cortical region. The sections were analyzed and spatial coordinates for each color microspheres were obtained. Mathematical analysis is location and density were used to estimate local perfusion as a function of time. This method of analysis at normal physiological conditions and after infusion of nephro toxic acellular hemoglobin, in order determine reliability and sensitivity of the method. This method can be advantageous in quantitatively defining renal perfusion for normal and diseased physiological conditions, as well as applied to other tissues.Support or Funding InformationNIH grants from the Heart Lung and Blood Institute, P01‐HL110900, R01‐HL52684, and R56‐HL123015.