bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of ezrin in a novel 3D in vitro model for ADPKD as a new target in cystogenesis
Authors: Dixon Eryn E , Woodward Owen M 
Published: November 2023

The ciliopathy autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cystogenesis mediated by two ciliary proteins, polcystin‐1 (PC1) and polycystin‐2 (PC2/TRPP2). While the mechanism of cystogenesis in ADPKD is undefined, loss of function mutations in PKD1 or PKD2, which encode for transmembrane proteins PC1 and PC2/TRPP2, have been identified as initiators in cyst formation. Polycystins have been implicated in apical signal transduction facilitated by the primary cilium. Therefore, it is critical for understanding the downstream mechanism of cyst formation, including effects of aberrant proliferation, mislocalization of growth signals, and alterations in fluid secretion machinery. Our novel three dimensional (3D) cystogenesis model cultures primary renal cells from Pkd2fl/fl Pax8rtTA TetOCre +mTmG mice in Matrigel to investigate the effects of Pkd2 inactivation on tubulogenesis. Tubule formation in this 3D culture method is promoted by seeding cells between two layers of Matrigel and the manipulation of glial derived neurotrophic factor (GDNF) exposure. Following the induction of Cre, we observe a strong correlation between the mosaic mTmG reporter, the reduction in PC2 protein abundance, and the increase of cystic structures, strongly supporting the successful inactivation of Pkd2. Using this model, we explored possible disruption of the apical compartment and inappropriate recruitment of secretory machinery by looking closely at the critical scaffold and ERM family protein, ezrin. We found there is a significant decrease in apically localized ezrin in cells with inactivated Pkd2, a finding consistent with a disruption in the structure of the apical compartment. In nephrectomized human ADPKD cystic epithelia, ezrin localization is altered along the apical compartment of small cysts, where total ezrin and the phospho‐ezrin/radixin/moesin (p‐ERM) complex colocalize with basolateral markers. Interestingly, appropriate apical localization of ezrin is present in larger cysts, indicating that ezrin may be a critical player in the initiation of cystogenesis. Our 3D cystogenesis model for ADPKD demonstrates characteristics consistent with human ADPKD cysts and identifies important defects in membrane sorting mechanisms.Support or Funding InformationNIDDK 5P30DK090868 Baltimore PKD Core Center and NIH/NIGMS T32 GM008181 Training Program in Integrative Membrane Biology
Effects of endothelial‐specific interference with PPARγ activity in offspring born from AVP‐induced preeclamptic pregnancies
Authors: Nair Anand R , Mukohda Masashi , Agbor Larry N , Wu Jing , Sandgren Jeremy A , Grobe Justin L , Sigmund Curt D 
Published: November 2023

PPARγ is a ligand‐activated transcription factor known to regulate metabolic and vascular function. Dominant‐negative (DN) mutations in PPARγ result in hypertension, and synthetic agonists of PPARγ have been shown to reduce blood pressure. Previously we found that mice expressing DN PPARγ driven by an endothelium‐specific promoter (E‐DN) exhibit vascular dysfunction. Preeclampsia (PE) is a hypertensive disorder of pregnancy which programs cardio/metabolic disease in offspring. PE is associated with vascular dysfunction, and we therefore hypothesized a role for endothelial PPARγ in the pathogenesis of PE and its sequelae. To test this, C57BL/6J dams were bred with E‐DN sires, and symptoms of PE were induced by the infusion of vasopressin (AVP, 24 ng/hr, sc) throughout gestation. We assessed phenotypes of PE first in pregnant dams, and then in offspring as adults. Compared to saline infusion (SAL), AVP induced significant elevations in maternal blood pressure (SBP in SAL 107±3 vs AVP 116±3, p<0.05) at gestational day 14–15 and urine protein (SAL 27±4 vs AVP 70±6 mg/mL, p<0.05) at gestational day 18. Offspring to these pregnancies were then genotyped and allowed to grow to adulthood to assess cardio‐metabolic function across three factors (offspring sex, offspring genotype, and maternal exposure to AVP vs SAL). A few notable findings of this ongoing, longitudinal study include: at 9 weeks of age, male NT mice born to AVP‐infused pregnancies had increased body mass compared to mice born from SAL‐infused pregnancies (21.3±0.1g in AVP‐WT vs 18.7±1.1 in SAL‐WT, p<0.05). In utero exposure to AVP significantly increased urinary protein levels in E‐DN (41±2.7 in AVP‐E‐DN vs 28±3.6 in SAL‐E‐DN, p<0.05) but not in NT mice (39±3.0 in AVP‐NT vs 29±2.0 in SAL‐WT). Exposure to AVP in utero significantly decreased proportional body fat in female NT (5.6±0.3% in AVP‐NT vs 8.6±1.5% in SAL‐NT, p<0.05) but not in E‐DN (5.6±0.4% in AVP‐E‐DN vs 7.3±0.6% in Sal‐E‐DN). E‐DN, but not WT, females born to pregnancies complicated by AVP infusion had increased proportional body fluid mass compared to E‐DN born to SAL pregnancies (6.8±0.1% in AVP‐E‐DN vs 6.0±0.0% in SAL‐E‐DN, p<0.05 and 6.5±0.1% in AVP‐NT vs 5.9±0.0% in SAL‐NT, n.s). These data highlight the impact of in utero exposure to elevated AVP upon cardiovascular function in the mother, and some of the consequences of this manipulation upon offspring. In addition, the data highlight the complex interactions that endothelial‐specific loss of PPARγ may have upon offspring health.Support or Funding InformationNIH and AHA funding
Obese Melanocortin‐4 Receptor (MC4R)‐Deficient Pregnant Rats Have Increased Blood Pressure With Reduced Circulating Placental Growth Factor Levels
Authors: Spradley Frank Travis , Granger Joey P 
Published: November 2023

Preeclampsia is a pregnancy‐specific disorder of hypertension, which significantly increases the immediate and long‐term morbidity of mother and offspring. Obesity is a major risk factor for preeclampsia, but the mechanisms linking obesity to this maternal disorder are unknown. Studies in humans have suggested that a greater angiogenic imbalance mediates this increased risk. Preeclampsia is thought to result from placental ischemia and release of anti‐angiogenic factors, such as sFlt‐1, into the maternal circulation where it reduces bioavailability of vascular protective and angiogenic factors, like placental growth factor (PlGF). We have shown previously, in two separate studies, the PlGF prevents placental ischemia‐induced hypertension in rats and that obese MC4R‐deficient rats have increased sFlt‐1 levels and blood pressure during pregnancy. Therefore, we tested the hypothesis that MC4R‐deficient pregnant rats have increased blood pressure with reduced circulating levels of PlGF. MC4R+/+ and MC4R+/− rats were maintained on a standard chow diet and timed‐pregnancies generated at 15 weeks of age using genotyped‐matched males. Carotid catheters were implanted on gestational day 18 for conscious mean arterial pressure (MAP) measurements and plasma collection on day 19. At day 19, absolute body weights were greater in MC4R+/− (n=13) over MC4R+/+ (n=10) pregnant rats (371±9 vs. 340±6 g, P<0.05), as was retroperitoneal adipose tissue mass (13±1 vs. 9±1 g, P<0.05). Circulating levels of leptin (6.7±1.0 vs. 3.5±0.4 ng/mL, P<0.05) were also greater in the obese pregnant rats. MAP was greater in the obese pregnant rats (108±2 vs. 101±1, P<0.05). In addition, circulating sFlt‐1 levels were doubled in the obese pregnant rats (440±128 vs. 252±106 ng/mL) but not in placental tissue (136±10 vs. 143±7 ng/mL). In contrast, the obese MC4R+/− pregnant rats had significantly reduced plasma levels of PlGF (45±10 vs. 121±34 pg/mL, P<0.05) but not in the placenta (496±152 vs. 508±183). In conclusion, these data suggest that the increased blood pressure found in obese MC4R‐deficient pregnant rats is associated with reduced circulating PlGF, and that therapeutic strategies to restore PlGF levels may be a way to reduce the increased incidence of preeclampsia in obese pregnancies.Support or Funding InformationK99HL130577, HL51971, P20GM104357
Circulating Cell‐free DNA and Maternal Cardiovascular Responses In Healthy Pregnancy And Postpartum
Authors: Goulopoulou Styliani , Sprouse Marc , Phillips Nicole R , Jarvis Sara J , Okada Yoshiyuki , Fu Qi 
Published: November 2023

BackgroundPregnancy is an inflammatory state that is characterized by vast adaptations of the maternal cardiovascular system. Changes in maternal cardiovascular function ensure adequate blood flow to the fetoplacental unit and inflammation promotes embryo implantation, pregnancy maintenance, and delivery. Cell‐free nucleic acids are increased in various inflammatory conditions and cardiovascular diseases as well as in normal pregnant women. The temporal changes of cell‐free DNA (mitochondrial and nuclear) during normal pregnancy and their effects on maternal cardiovascular adaptations to pregnancy are unknown.ObjectivesTo determine the levels of cell‐free DNA in the circulation of pregnant women at different gestational ages and postpartum, and to examine the relationship between circulating cell‐free nucleic acids and maternal cardiovascular parameters.MethodsMaternal blood samples were collected at early (≤ 8 weeks of gestation) and late (32–36 weeks) pregnancy, and post‐partum (6–10 weeks after delivery) in healthy, normotensive, pregnant women (N=21). All participants were non‐smokers and had no overt history of gestational hypertensive disorders or chronic diseases. Absolute real‐time PCR quantification of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) was performed on whole genomic extracts from maternal serum using TaqMan® probes and chemistry.ResultsCirculating levels of mtDNA in late pregnancy were greater compared to early pregnancy (0.022 ± 1.2 pg/μL vs. 0.04 ± 1.2 pg/μL, p=0.04) and remained elevated post‐partum (0.031 ± 1.2 pg/μL). Circulating levels of nDNA did not significantly change from early to late pregnancy (p=0.14) but they were lower postpartum compared to late pregnancy (31.1 ± 1.2 ng/μL vs. 14.7 ± 1.2 ng/μL, p=0.007). There were no differences between nulliparous (n=10) and multiparous women (n=11) in concentrations of circulating cell‐free nucleic acids (reproductive stage × parity interaction, p=0.27). There were significant correlations between mtDNA and nDNA for each gestational age and postpartum (early pregnancy, r=0.64; late pregnancy, r=0.72; postpartum, r=0.67; p≤0.004). Both blood pressure and heart rate increased from early to late pregnancy and decreased postpartum (p<0.05). MtDNA and nDNA correlated neither with maternal cardiovascular parameters (systolic and diastolic blood pressure, heart rate) nor with neonatal parameters (neonatal length and weight).ConclusionCirculating levels of mtDNA and nDNA change with advancing gestational age and may reflect rates of placental cell apoptosis. It is unknown whether cell‐free DNA acts as a signaling molecule and if it plays a role in maintenance of pregnancy.Support or Funding InformationAHA Scientist Development Grant (13SDG17050056); NIH R21 grant (HL088184); AHA Grant‐in‐Aid (13GRNT16990064); The Harry S. Moss Heart Foundation
20‐HETE Impedes Trophoblast Migration and Contributes to Hypertension in the RUPP Rat Model of Placental Ischemia
Authors: Murphy Sydney , Lee Nicole , Faulkner Jessica , Spencer Shauna‐Kay , Wallace Kedra , LaMarca Babbette 
Published: November 2023

Few studies exist on cytochrome P450 (CYP450) metabolites of arachidonic acid (AA) pertaining to the pathophysiological events in pregnancy. Therefore, the goal of this study was to determine a role for 20‐Hydroxyeicosatrienoic acid (20‐HETE), a metabolite of the CYP450 enzyme, in trophoblast proliferation, migration, and hypertension during preeclampsia. Placental vascular CYP450 enzymatic activity and circulating eicosanoids were measured in normal pregnant (NP) and preeclamptic (PreE) patients. To determine a role for 20‐HETE on blood pressure we evaluated the effect of a 20‐HETE synthesis inhibitor, HET0016, on mean arterial pressure (MAP) in NP rats and the reduced uterine perfusion pressure (RUPP) rat model of PreE. PreE women displayed increased placenta 20‐HETE (0.1914 ± 0.025 pmol/min/mg, n=5, p<0.05) compared to NP women (0.1192 ± 0.017 pmol/min/mg, n=7) and increased ratio of circulating 20‐HETE:EETs compared to NP women (p<0.05). Importantly the increase in MAP in response to RUPP in rats (122 ± 3 mmHg) was attenuated with 20‐HETE blockade (112 ± 2 mmHg, p<0.05). To examine the role for CYP450 metabolites in trophoblast function, proliferation and migration assays were performed in the presence of exogenous 20‐HETE and HET0016. Trophoblast proliferation was increased with 20‐HETE (46%, p<0.05) and reduced with 20‐HETE blockade by HET0016 (75%, p<0.05). However, administration of exogenous 20‐HETE decreased trophoblast migration evaluated by scratch assay (p<0.05). In conclusion, alterations in the metabolism of AA, specifically increases in 20‐HETE, may contribute to pathophysiology of Pre by reducing trophoblast cell migration and causing hypertension in response to placental ischemia.Support or Funding Information14SDG20160020, 2RO1HD067541
βENaC is Required for Placental Vascular Remodeling in Mice
Authors: Warrington Junie Paula , Spradley Frank T , Chade Alejandro R , Ryan Michael J , Granger Joey P , Drummond Heather A 
Published: November 2023

During normal pregnancy, spiral arteries of the maternal uterus remodel into large, low‐resistance vessels to accommodate increasing blood flow to the developing utero‐placental unit. During spiral artery remodeling, endothelial and vascular smooth muscle cells (VSMCs) are replaced by fetal‐derived cytotrophoblasts. We and others have shown that beta Epithelial Na+ Channel protein (βENaC) is required for normal trophoblast migration in vitro. However, whether βENaC mechanistically contributes to trophoblast migration underlying placental vascular remodeling is unknown. In this study, we tested the hypothesis that bENaC is required for normal placental vascular remodeling. To address this, we examined placental vascular morphology and trophoblast/VSMC localization in mice with reduced βENaC expression (βENaCm/m). Mutant and wild‐type (βENaC+/+) controls were mated to generate age‐matched, timed‐pregnant mice. Micro‐computed tomography analysis of gestational day 14.5 placental vascular casts (n = 7–8 placentas) showed reduced spiral artery density (0.4 ± 0.1 vs. 0.7 ± 0.1 per mm2) and mean diameters (185.1 ± 6.9 μm vs. 225.0 ± 8.3 μm; p<0.01) in βENaCm/m mice compared to wild‐type mice respectively. Additionally, the central canal vessel diameter was also reduced in βENaCm/m mice (318.6 ± 11.8 vs. 373.0 ± 19.6 μm). There was no difference in the intervillous space. On gestational day 18.5, another group of placentas were collected for immunofluorescent detection of trophoblast (cytokeratin‐13, CK‐13) and smooth muscle cell (desmin) presence in spiral arteries. In βENaC+/+ mice, we detected cytotrophoblast, but not VSMC marker expression. However, CK‐13 expression was reduced and desmin increased in βENaCm/m placentas. Although pup (0.82 ± 0.04 vs. 0.85 ± 0.06 g) and placenta weights (110 ± 5 vs. 110 ± 3 mg) were similar in mutant and wild‐type mice, respectively, βENaCm/m mice had fewer live pups (5 ± 1 vs. 9 ± 1, p=0.002) on gestational day 18.5. Taken together, these findings suggest that βENaC is required for normal utero‐placental vascular remodeling during pregnancy and mice with reduced βENaC may compensate by having smaller litter size.Support or Funding InformationFunding: NIH grants P20GM104357, P01HL051971, K99HL129192, and the American Heart Association grant: 13POST16240000.
Knock‐down of ADAM17 in glutamatergic or pre‐autonomic neurons attenuates development of neurogenic hypertension
Authors: Basting Tyler M , Xu Jiaxi , Sriramula Srinivas , Murkerjee Snigdha , Lazartigues Eric 
Published: November 2023

Rationale and objectivesWe have previously reported that DOCA‐salt‐induced neurogenic hypertension is associated with a reduction of Angiotensin Converting Enzyme 2 (ACE2) and an increase in A Disintegrin And Metalloprotease 17 (ADAM17) activity in the hypothalamus. Blocking Angiotensin‐II type 1 receptors or silencing ADAM17 in the CNS prevented hypertension. Since ADAM17 is known to be expressed on different cell types in several brain regions and can be activated in multiple ways, we generated several specific knockout mice targeting ADAM17 in neurons, astrocytes and microglia. In one of these models, we tested the hypothesis that glutamatergic neurons expressing ADAM17 mediate ACE2 shedding from the cell membrane in neurogenic hypertension. Secondly, through selective knock‐down of ADAM17 in Sim1‐positive neurons we examined its role in pre‐autonomic neurons.MethodsPrimary neuronal cultures were used to substantiate glutamate's role in up‐regulating ADAM17 activity. In vivo, ADAM17 knock‐down mice (ADAM17 floxed crossed with either Vesicular Glutamate Transporter 2 ‐ cre or Sim1 – cre recombinase mice), and control littermates were implanted with telemetry probes for continuous recording of blood pressure (BP) and heart rate (HR) (N = 26 control; N = 3/group experimental). After baseline data were collected the mice underwent DOCA‐salt treatment (DOCA 1 mg/g body weight sc + 1% saline po) for 18–20 days.ResultsPrimary neurons exposed to glutamate showed increased expression of ADAM17 activity on the cell membrane (24.5±5%). Glutamatergic ADAM17 knock‐down animals, Sim1 ADAM17 knock‐down animals, and their control littermates showed increased BP after DOCA‐salt treatment (Control: +30 ±3 mmHg; ADAM17fl/flvGlut2: +10 ±4 mmHg; ADAM17fl/flSim1: +21.4 ±5). Importantly, mean arterial pressure and HR were significantly lower in mice with ADAM17 knocked‐down from glutamatergic neurons or Sim1 neurons after DOCA‐salt treatment compared to the controls (p<0.01 for all comparisons).ConclusionsADAM17 expression on glutamatergic neurons or Sim1 positive neurons does not influence BP and HR during normal resting conditions. However, this is the first evidence showing that these neuronal populations of ADAM17 positive cells are playing a critical role in mediating hypertension. Under DOCA‐salt‐induced neurogenic hypertension BP and HR both increase via pathways involving glutamatergic and Sim1 neurons with ADAM17.Support or Funding InformationNIH: HL093178 and GM106392; AHA: 12EIA8030004
Whey Protein Improves Glucose Uptake Following Exercise via DPP‐IV and IL‐6
Authors: Neidert Leslie E , Kluess Heidi A 
Published: November 2023

Following a bout of exercise, glucose is taken up from the blood by the muscle as a fuel to provide energy. This occurs via translocation of GLUT4 to the muscle membrane. Interleukin 6 (IL‐6) is a modulator of GLUT4 translocation, but this can be altered by the myokine, dipeptidyl peptidase IV (DPP‐IV). The purpose of this study was to investigate glucose uptake following exercise with supplementation and the role of DPP‐IV and IL‐6 in its modulation.Twenty‐three college‐aged participants were randomly assigned to one of three supplementation conditions (CTL: water, WPI: whey protein isolate, and CHO: fructose beverage; WPI and CHO beverages were isocaloric). On the Baseline Visit, participants completed an Oral Glucose Tolerance Test (OGTT) with no exercise or supplementation. Their Blood Glucose was monitored every 10 minutes until they “cleared” the glucose (Blood glucose<140, ADA). On their second and third visits, participants were asked to consume their supplement beverage then complete a maximal treadmill protocol until volitional fatigue. A second OGTT was completed on the second visit, and blood samples were collected via venipuncture on the third visit for IL‐6, Insulin and DPP‐IV. IL‐6 and insulin were determined via ELISAs, and DPP‐IV activity was determined by fluorescent assay.Glucose uptake was significantly increased following exercise in the WPI group (Glucose AUC: WPI+Rest= 10600±4589mg/dl*time and WPI+EX= 5993±1013mg/dl*time; p=0.03), but not in the CTL or CHO groups. Additionally, glucose appearance (Peak‐Baseline) was decreased in the WPI group following exercise (WPI+Rest= 79±31mg/dl and WPI+EX= 40±19mg/dl; p=0.006). IL‐6 and DPP‐IV were both significantly increased in the WPI group after exercise (IL‐6: WPI+Rest= 7.72±12.06pg/ml and WPI+EX= 8.12±12.25pg/ml; p=0.004; DPP‐IV: WPI+Rest= 42.29±9.08U/L and WPI+EX=50.40±8.61U/L; p=0.008), and only IL‐6 was significantly increased following exercise in the CTL group (CTL+Rest=1.16±0.87pg/ml and CTL+EX= 1.63±0.86pg/ml; p=0.04). Insulin increased with all groups from rest following exercise (p<0.05), but there were no condition differences.Whey protein supplementation potentiated glucose uptake possibly via IL‐6 modulated GLUT4 translocation. Because DPP‐IV was significantly increased in the WPI group only, it is possible that this was in response to the IL‐6 increase, but it did not seem to have a negative effect. This has important implications in supplementation and fuel usage during exercise, and future research should investigate the release of DPP‐IV from the muscle in response to exercise and whey protein and its interaction with IL‐6 in the interstitial space.Support or Funding InformationThis study was funded by the Auburn University College of Education Seed Grant
Changes in Osteoprotegerin and Sclerostin Across a Training Season in Olympic Female Rowers
Authors: Kurgan Nigel Kilty , Pepper Connor , Logan‐Sprenger Heather , Falk Bareket , Klentrou Panagiota 
Published: November 2023

Exercise training is generally associated with an increase bone mineral density (BMD) but this adaptation is reversed during extended periods of intense training. Furthermore, examination of serum markers of bone turnover has shown an unbalanced increase in bone resorption over bone formation during high volume training. However, the molecular events that precede these changes in bone turnover remain unclear. One pathway related to mechanical loading is the Wnt signalling pathway. Osteoprotegerin (OPG) is a transcription product of Wnt signalling leading to inhibition of bone resorption. Sclerostin (SOST) is an inhibitor of Wnt signalling leading to reduced formation. Therefore, the purpose of this project was to monitor changes in OPG and SOST at times of different training volumes during the pre‐Olympic training season in female rowers. Insulin like growth factor (IGF‐1) and leptin, two other factors that are sensitive to training and have been associated with Wnt signalling were also examined. Blood samples were drawn from female heavy‐weight rowers (n=15, 27.0 ± 0.8 y, 80.9 ± 1.3 kg, 179.4 ± 1.4 cm) at baseline (T1 – 11 months pre‐Olympic Games) and following 1 (T2), 2 (T3), 6 (T4), 7 (T5) and 9 months (T6). Serum was analyzed by Multiplex assays (EMD Millipore, Toronto, CAN). Total weekly training volume was recorded over the week prior to each time point. BMD was measured at multiple sites by dual energy X‐ray absorptiometry at T1 and T6. OPG decreased significantly from T2 to T6 (−28.7%, p<0.05) and SOST levels were increased at T5 compared to T6, T4, T3 and T2 (993.1 vs. 741.0, 709.3, 759.7 and 774.2 pg/mL respectively, p<0.05). IGF‐1 was not changed over time. Leptin increased from T1 to T6 (+84%, p<0.05). Weekly training volume prior to T1 through T6 was 1020, 730, 1270, 1135, 1165 and 1200 min/wk, respectively. No change in BMD was observed at any bone site from T1 to T6. Therefore, over the course of the training season, OPG concentrations decreased while leptin and SOST concentrations increased, suggesting an increased bone formation and decreased bone resorption. In summary, bone biochemical markers were affected during the pre‐Olympic training season in female rowers, but BMD remained unchanged. However, the pattern of changes in osteokines, reflecting dynamic deviations in bone remodelling were not sensitive to changes in training volume.Support or Funding InformationCanadian Sports Institute