bluuebunny/crossref_metadata_2025_split huggingface dataset:
Claudin‐2 Confers Calcium Permeability to the Jejunum and Ileum in Early Life
Authors: Beggs Megan R , Plain Allen , Lee Justin J , Alexander R. Todd 
Published: June 2021

Infants and children must maintain a net positive calcium (Ca2+) balance in order to achieve an optimal peak bone mineral density by early adulthood. Across the small intestine, Ca2+ is absorbed via transcellular and paracellular pathways although the molecular details of these pathways in early life are not well delineated. Claudins are tight junction proteins that confer selective permeability to epithelia. Claudins‐2, −12 and −15 are expressed and have been implicated in paracellular Ca2+ permeability across intestinal epithelia. To date, the functional contribution of these claudins to the Ca2+ permeability (PCa2+) of small intestine segments has not been defined. The objective of this study was therefore to 1) determine if PCa2+ across small intestine segments changed with postnatal development 2) to asses whether claudin‐2 or −12 contribute PCa2+ to the small intestine. To this end, basolateral to apical 45Ca2+ fluxes on ex vivo intestinal segments in Ussing chambers were employed to indirectly assess permeability to Ca2+. We observed greater 45Ca2+ flux in P14 vs 2‐month mice across the duodenum (31.8 ± 2.2 vs 9.5 ± 2.0 nmol/h/cm2, P<0.0001) and jejunum (42.3 ± 3.9 vs 21.8 ± 3.5 nmol/h/cm2, P<0.01) but not ileum (40.5 ± 3.2 vs 30.1 ± 5.7 nmol/h/cm2, P=0.13). Next, we measured PCa2+ directly in Ussing chambers using diffusion potentials. PCa2+ was significantly greater in younger mice across the duodenum (1.43 ± 0.04 vs 1.13 ± 0.08 × 10−4cm/s, P<0.01), jejunum (1.64 ± 0.09 vs 0.84 ± 0.04 × 10−4cm/s, P<0.0001) and ileum (1.72 ± 0.08 vs 0.81 ± 0.05 × 10−4cm/s, P<0.0001). To determine if claudin‐2 or −12 facilitates greater PCa2+ at P14, diffusion potential experiments were repeated on Cldn2 or Cldn12 knockout (KO) mice. PCa2+ was decreased in Cldn2 KO mice at P14 across the jejunum (1.85 ± 0.09 vs 1.24 ± 0.07 × 10−4cm/s, P<0.0001) and ileum (1.92 ± 0.07 vs 1.09 ± 0.06 × 10−4cm/s, P<0.0001) to levels not different than 2‐month WT and KO mice. No differences were observed between Cldn12 knockout mice compared to wildtype littermates at either age. We conclude that the younger mice have enhanced Ca2+ permeability along the small intestine relative to older animals. Further, the increased jejunal and ileal Ca2+ permeability is mediated by claudin‐2 which likely contributes to a positive calcium balance for normal growth.Support or Funding InformationThis work was funded by grants from the Women and Children's Health Research Institute, which is supported by the Stollery Children's Hospital Foundation, and the National Sciences and Engineering Research Council to RTA, who is the Canada Research Chair in Renal Epithelial Transport Physiology. MRB is supported by a Vanier Canada Graduate Scholarship, and Alberta Innovates Clinician Fellowship.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
H89 Phosphoproteomics in PKA‐Null Cells
Authors: Kelleher Andrew , Limbutara Kavee , Yang Chin‐Rang , Raghuram Viswanathan , Knepper Mark 
Published: June 2021

Protein phosphorylation, mediated by protein kinases, plays a crucial role in cellular regulation. One of the most important protein kinases is protein kinase A (PKA). N‐[2‐p‐bromocinnamylaminoethyl]‐5‐isoquinolinesulphonamide (H89) is often used as a “PKA specific inhibitor” to study the involvement of PKA in signaling pathways. However, evidence from cell‐free experiments has suggested that H89 can also inhibit other protein kinases. In this study, previously generated PKA‐null and PKA‐intact mouse cell lines were treated with H89 over a range of concentrations commonly used in the literature, followed by mass spectrometry‐based phosphoproteomics to globally assess changes in phosphorylation. From a total of 14,507 phosphorylation sites quantified, we found that 578 and 267 phosphorylation sites with significant changes in abundance in PKA‐intact and PKA‐null cells, respectively. Analyses of sequence logos generated from significantly decreased phosphorylation sites in PKA‐intact and PKA‐null cells both revealed a preference for basic amino acids at position −3 and −2. Thus, H89 appears to inhibit basophilic kinases, even in the absence of PKA. We conclude that, in intact cells, H89 can affect activities of protein kinases other than PKA, and therefore responses to H89 should not be regarded as a sufficient evidence for PKA involvement in a signaling process.Support or Funding InformationThis work was funded by the Division of Intramural Research, National Heart, Lung, and Blood Institute (projects ZIA‐HL001285 and ZIA‐HL006129, MAK). Andrew Kelleher was a member of the Biomedical Engineering Student Internship Program (BESIP, Robert Lutz, Director) supported by the National Institute for Biomedical Imaging and Bioengineering (June–August 2018). All mass spectrometry measurements were performed by the NHLBI Proteomics Core Facility (M. Gucek, Director).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Systemic Maternal Inflammation and Postnatal Hyperoxia Induces Early Life Cardiovascular Abnormalities in Mice
Authors: Pavlek Leeann R , Rogers Lynette 
Published: June 2021

BackgroundPremature infants have a higher incidence of heart failure, cardiac hypertrophy, and ventricular systolic dysfunction as young adults. The mechanism underlying these abnormalities likely include changes in proteins related to the structure and function of the heart including connexin 43, α myosin heavy chain (αMHC), and β myosin heavy chain (βMHC). microRNAs, including miR‐208a and miR‐208b, play a role in the regulation of myosin heavy chain expression. In adult mice, abnormalities in these proteins and microRNAs are triggered by perinatal inflammation and postnatal hyperoxia. These investigations test our hypothesis that systemic maternal inflammation and neonatal hyperoxia induce changes in the structural and conduction proteins of the mouse heart and are present in embryonic and newborn mice.MethodsPregnant C3H/HeN mice were injected on embryonic day 16 (E16) with intraperitoneal LPS (80 μg/kg) to induce perinatal inflammation or saline. Offspring were euthanized on E18 or day of life 1. Another group of offspring were placed into room air (RA) or 85% O2 for 7 days after birth prior to euthanizing. Total RNAs were isolated from frozen whole heart samples. RT‐PCR was used to examine mRNA expression of connexin 43, αMHC, and βMHC. RT‐PCR was also used to assess expression of miR‐208a and miR‐208b. Data were analyzed using an unpaired t‐test.ResultsMaternal LPS induces decreases in miR‐208b that are present at E18 (10‐fold, P<0.05) and persist at day of life 1 (15‐fold, P<0.05). At day of life 7, oxygen exposure induces a downregulation of miR‐208b (1.8‐fold, P<0.05) compared to room air. The inflammation‐exposed mice have significant decreases in miR‐208a (9‐fold, P<0.05) and αMHC mRNA (30,000‐fold, P<0.05) on day of life 1. By day of life 7, mice exposed to the combination of inflammation and hyperoxia have less (1.6‐fold, P<0.05) connexin 43 mRNA compared to the control mice; no changes in connexin 43 are seen at day of life 1 or at day of life 7 with exposure to inflammation without hyperoxia.ConclusionsMice exposed to perinatal inflammation and postnatal hyperoxia demonstrate changes in structural and conduction components of the heart that are evident at the time of birth.Support or Funding InformationNIH NICHD R01HD088033This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
CC chemokine ligand 2 (CCL2) stimulates local aromatase expression in mammary adipose tissue via MAPK/ERK signaling pathway
Authors: Martínez‐Chacón Gabriela , Saarinen Niina , Mäkelä Sari 
Published: June 2021

Obesity is an important risk factor for the most common type of breast cancer, i.e., estrogen‐dependent postmenopausal breast cancer. Obesity‐related inflammation, defined by enhanced tissue macrophage infiltration and increased levels of proinflammatory factors, stimulates estrogen production and, in turn, promotes tumor formation and progression. The augmented inflammatory milieu activating aromatase expression, the rate‐limiting enzyme for estrogen synthesis, is suggested to be the major mechanism behind the increased risk for breast cancer. The regulation of aromatase (CYP19A1) gene expression in breast tissue is complex and not fully understood. This study focuses on the role of CCL2, a macrophage recruiter often overexpressed in the obese and cancerous breast tissue, on the aromatase expression in mammary adipose tissue. We utilized mammary adipose tissue explants obtained from female hARO‐Luc aromatase reporter mice and cultured primary human breast adipose stromal cells (hASCs). In tissue explants, aromatase expression was measured by quantification of luciferase reporter activity, while in cultured hASCs, qPCR was used to examine expression of CYP19A1 and its specific promoter I.4 and II transcripts. Both, in mammary adipose tissue and in hASCs, CCL2 induced aromatase expression via the distal promoter I.4. Moreover, inhibitors of CCL2 receptor and MAPKs pathway, ERK1/2, blocked CCL2–induced CYP19A1 and PI.4 mRNA expression. In conclusion, these findings indicate that CCL2, an intrinsic pro‐inflammatory chemokine in adipose tissue, may stimulate aromatase expression and play an important role in controlling estrogen biosynthesis in the breast adipose stroma.Support or Funding InformationThis research is supported by the University of Turku Graduate School, the Finnish Cultural Foundation, the Turun yliopistosäätiö and the Institute of Biomedicine, University of TurkuThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Single Prolonged Stress as a Prospective Model for Posttraumatic Stress Disorder in Females
Authors: Nwokafor Chiso , Navhi Roxanna J , Serova Lidia , Sabban Esther 
Published: June 2021

BackgroundSex plays an important role in susceptibility to stress triggered disorders. Posttraumatic Stress disorder (PTSD), a debilitating psychiatric disorder developed after exposure to a traumatic event, is two times more prevalent in women than men. However, the vast majority of animal models of PTSD, including single prolonged stress (SPS), were performed mostly with males.Objectives(1) Evaluate SPS as an appropriate model for PTSD in female rodents in terms of anxiety, depressive symptoms and changes of gene expression in the locus coeruleus; (2) Asses sex differences in SPS‐triggered changes in these measures; (3) Examine intranasal NPY as a potential early intervention for females.MethodsFemale rats were subjected to SPS and given either intranasal NPY or vehicle. Twelve and seven days later they were compared to unstressed controls on forced swim test (FST) and elevated plus maze (EPM) respectively. Changes in gene expression in the locus coeruleus (LC) were determined by quantitative RT‐PCR.Results and InterpretationSPS led to increased anxiety‐like behavior on EPM, and tended to raise depressive‐like behavior on FST. Following FST rats displayed elevated TH, CRHR1 and Y1R mRNA levels in the LC, consistent with increased activation of the noradrenergic system.The expression level of these mRNAs were unchanged following EPM. Intranasal NPY at the doses shown to be effective in males, did not prevent development of depressive or anxiety‐like behavior or molecular changes in the LC. SPS may be milder for females when compared to males, as they did not show despair or immobility as readily as males on the forced swim component of the SPS protocols. In addition, after SPS stressors females exhibited less immobility on FST than males, however there were little overall sex differences in anxiety‐like behavior on EPM.ConclusionsThe results indicate that while SPS could be an appropriate PTSD model for females, there are important sex differences, such as response to NPY, that need to be taken into account.Support or Funding InformationThis work was supported by the Office of the Assistant Secretary of Defense for Health Affairs through the DOD Department of Defense Broad Agency Announcement for Extramural Medical Research under Award No W81XWH‐16‐1‐0016 and by funds from the NYMC/Touro Bridge Funding Program.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Endothelin B Receptor Blockade Lowers Fasting Blood Glucose and Improves Insulin Sensitivity in Rats
Authors: Williams London J , Jenkins Haley N , Speed Joshua S 
Published: June 2021

Elevated endothelin‐1 (ET‐1) is associated with obesity, as well as insulin resistance. We previously reported that rats lacking functional endothelin type B receptors (ETB) demonstrate improved glucose control. In addition, ETB receptor deficient rats have hypertension due to overactivation of the endothelin type A receptor (ETA). In order to determine the effects of ETA receptor activation on insulin sensitivity, we tested the hypothesis that pharmacological blockade of ETB receptors and dual ETA/ETB receptor inhibition would improve glucose control in Sprague Dawley (SD) rats. SD rats were treated with Bosentan (30 mg/kg/day), Atrasentan (10 mg/kg/day), A‐192621 (10 mg/kg/day), or vehicle over a period of two weeks. At day 7, insulin tolerance testing was performed and tissues were collected at day 14 after a 6‐hour fasting period. Treatment with either the dual ETA/ETB antagonist Bosentan, or the ETB antagonist A‐192621, significantly lowered fasting blood glucose as compared to either vehicle or ETA antagonist (Atrasentan) (82.72±4.2*, 75±6.1*, 99.1±2.0, and 94.8±3.2 mg/dl respectively, *p<0.05 vs. vehicle). In addition, both Bosentan and A‐192621 improved insulin tolerance compared to vehicle treated, while Atrasentan had no effect. There were no differences in plasma cholesterol (LDL or HDL) or triglycerides. These data indicate that blockade of ETB receptors improves glucose control and may be an effective treatment for insulin resistance and pre‐diabetes.Support or Funding InformationThis work is supported by NHLBI grant R00 HL127178 to JSS.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Chronic Nicotine Worsens Blood Pressure and Renal Injury on Hyperandrogenemic Female Rats
Authors: Maranon Rodrigo Oscar , Reckelhoff Jane F. 
Published: June 2021

Polycystic ovary syndrome (PCOS) affects to 5–7% of reproductive‐age women. It is characterized by hyperandrogenemia, insulin resistance, metabolic dysfunction, and cardiovascular and renal complications. Approximately 40% of women with PCOS have current or past smoking history (vs. healthy women 13 – 17%), that is associated with worsening of insulin resistance and metabolic dysfunction. However, whether nicotine worsens renal injury and exacerbates the elevated blood pressure in PCOS women is unknown. We have a well‐characterized model of PCOS, the hyperandrogenemic female rat (HAF rat) that mimics the cardiovascular and metabolic dysfunction present in PCOS women. In the present study, we tested the hypothesis that chronic nicotine in HAF rats worsens renal injury and hypertension. Virgin female rats were implanted with dihydrotestosterone (pellets DHT: 7.5 mg/90 d pellet, sc: HAF rats) or placebo pellets (controls: Ctr) beginning at 4–5 weeks of age. Chronic nicotine (Nic: 12.5 ug/ml) or vehicle (Veh: Sweet'n Low 2%) in drinking water was given to placebo and HAF rats (n=3/gpr) for 28 days beginning at 14 weeks of age. Mean arterial pressure (MAP, by telemetry) was measured for 7 days and at the end of this period, 24h urine and plasma samples were collected. Cotinine levels were higher in both groups treated with Nic. Nic increased proteinuria and plasma creatinine in HAF rats compared to Ctr rats (Plasma Crea: Ctr+Veh: 0.23±0.04 mg/dl vs. Ctr+Nic: 0.37±0.13 mg/dl and HAF+Veh: 0.82±0.08 mg/dl vs. HAF+Nic: 1.17±0.08 mg/dl). Also, chronic Nic exacerbated MAP only in HAF rats (Ctr+Veh: 102±1 mmHg vs. Ctr+Nic: 104±1 mmHg, p=NS; HAF+Veh: 110±1 mmHg (p<0.05 vs untreated control vs. HAF+Nic: 115±2 mmHg; p<0.05, vs HAF vehicle). These data suggest that chronic Nic may contribute to increased cardiovascular and renal disease in women with PCOS. Preclinical studies into possible mechanisms by which Nic induces its effect are needed.Support or Funding InformationSupported by AHA14POST18640015 (ROM) and P20GM121334 (ROM and JFR).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Molecular mechanisms underlying the GRK4 65L‐mediated hypertension in mice
Authors: Rozyyev Selim , Konkalmatt Prasad , Villar Van Anthony M , Asico Laureano D , Kumar Megha , Hunt Jessica , Jose Pedro A , Armando Ines A 
Published: June 2021

The genetic causes of salt sensitivity andhypertension in humans are not completely understood. The kidney plays a preeminent regulatory rolein blood pressure (BP) homeostasis and water and electrolyte balance. The renaldopamine receptors, D1R and D3R, engender natriuresis viathe inhibition of renal Na+ transport, whereas the angiotensin IItype 1 receptor (AT1R) does the opposite. The renal paracrineinhibition of Na+ transport by dopamine is impaired insalt‐sensitive rats, mice, and humans. Agonist activation promotes thephosphorylation of D1R and D3R by the G protein‐coupledreceptor kinase type 4 (GRK4), whose gene variants impair D1R and D3Ractivity. The global expression of GRK4 65R>L in transgenic mice results in salt‐sensitive hypertension, in part, due toincreased endogenous GRK4 and AT1R expression. To demonstrate thespecific renal causal mechanisms in GRK4 65R>L‐mediated hypertension, weheterologously expressed the GRK4 65R>Lvs. GRK4 wild‐type (WT) transgenes in the kidneys of Grk4 knockout mice on normal salt diet. The transgenes were delivered selectively into the renal tubules by thebilateral retrograde ureteral infusion of AAV‐9 vectors. The expression anddistribution along the entire nephron of the GRK4 WT and GRK4 65R>L were similar in both groups. However, the renal tubule‐restricted expression ofGRK4 65R>L increased the BP (117±4vs. 93±1 mm Hg, P<0.05, n=4), while that of the GRK4 WT only tendedto increase the BP (105±6 vs. 96±2 mmHg, n=5), indicating that the presence of the GRK4 variant in the kidney causedthe increase in BP. We next evaluated the renal expression profiles of selectgenes. We found that the pro‐natriuretic D1R (0.81±0.01 vs. 1.28±0.04, P<0.01) and D3R(0.44±0.02 vs. 1.27±0.07, P<0.01)were decreased whereas the anti‐natriuretic Na+/K+‐ ATPase(1.14±0.024 vs. 1.0 ±0.007, P<0.05) and α‐ENaC (1.4±0.14 vs. 1.0±0.11, P<0.05) were increased, demonstrating themechanistic changes that underlie the hypertension in these mice. Interestingly, we also observed that the proximal tubule Na+transporters NaPi2 (0.81±0.02 vs. 1.04±0.02), SGLT2 (0.89±0.03 vs. 1.07±0.05), NBCe2(0.50±0.07 vs. 1.15±0.03), and the AT1R(0.82±0.02 vs 1.02±0.02) were decreased, which may represent insufficientcompensatory mechanisms against the increase in BP. Our results highlight theunderlying and compensatory renal mechanisms for the hypertension thatdeveloped in mice with either kidney‐restricted or globally expressed GRK4 65R>L.Support or Funding InformationR01DK039308, R01HL092196, and P01HL074940This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Using a Learning Progression Framework and Assessments to Improve Principle‐based Instruction in Physiology
Authors: Wenderoth Mary Pat , Scott Emily E. , Cerchiara Jack A , McFarland Jenny , Doherty Jennifer H 
Published: June 2021

Using scientific principles to reason about biological phenomena is an essential part of scientific thinking. However, students frequently view biology as a discipline full of facts to be memorized without recognizing the fundamental principles that bring coherence to biological phenomena. This can cause students to develop fragmented, superficial knowledge that is topic specific instead of developing rich reasoning frameworks that identify fundamental relationships among elements in complex systems. To address this concern, we created and implemented a principle‐based instructional approach focused on flux (flux ~ gradient/resistance) as a unifying principle that explains material movement across multiple physiological phenomena. We grounded our approach in learning progression research, which uses a cognitive framework of student thinking (i.e., the learning progression) that describes how students' ideas about a topic gain sophistication through time. Learning progressions enrich instruction by aligning three key aspects of instruction: 1) learning outcomes that describe the key behaviors students must exhibit to show proficiency in a topic, 2) formative and summative assessments that evaluate the breadth of student thinking beyond a right/wrong analysis, and 3) instructional strategies that leverage students' emerging ideas in ways that shift them towards sophisticated scientific ideas.We present our learning progression after one round of modeling student thinking about the concept of flux, deploying assessments that elicited a range of student ideas about flux in multiple physiological contexts (i.e., 29 constructed response items to 2956 undergraduate biology students at two R1 institutions and two community colleges ), and analyzing student data for reasoning patterns. We show how this process helped us: 1) better define learning outcomes that captured key reasoning hurdles students must overcome to achieve proficiency in flux topics, 2) develop and revise assessment items that could elicit sophisticated student reasoning about flux, and 3) create instructional tools that guide students towards principle‐based reasoning approaches. Learning to reason with scientific principles and recognizing fundamental patterns across biological systems is a key shift in student thinking that moves students away from novice views towards more expert‐like thinking necessary for successful biology careers in STEM fields.Support or Funding InformationNSF DUE 1661263This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.