bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of pre‐ and postnatal diets on body compositions of diet‐induced obesity prone Sprague‐Dawley rats
Authors: Uthus Eric O , Claycombe Kate J , Johnson William Thomas
Published: June 2021

Increasing numbers of studies have shown that growth retardation due to malnutrition during the fetal growth period followed by postnatal catch‐up growth results in obesity. To determine whether a prenatal low‐protein diet followed by postnatal high‐fat diet increase offspring's propensity to obesity, we fed obese‐prone Sprague‐Dawley females a diet containing 10% fat and either 8% (LP) or 20% (NP) protein for 3 wk prior to breeding and through pregnancy and lactation. At weaning, male offspring were placed on a 20% protein diet containing either 10% (NF) or 45% (HF) fat, thus, giving 4 groups (LP‐NF, NP‐NF, LP‐HF, NP‐HF). Results indicated that birth weights of offspring born of LP or NP fed dams were not different. However, at weaning, body weights of offspring born of NP diet fed dams were 2‐fold greater than that of LP fed dams. After 12 weeks of postnatal NF or HF diet, offspring of LP dams compared to that of NP dams had greater rates of body weight increase (fold‐increase, 11.0 vs. 6.3). Similarly, the rate increases in adipose tissue (23.4 vs. 12.6) and lean body (12.9 vs. 7.7) mass were greater in the offspring of LP dams compared to offspring of NP dams. In both LP and NP groups, postnatal NF and HF diets had no effects on body weight, adipose tissue and lean mass. These data suggest that low protein intake during pregnancy and lactation predisposes offspring to greater rates for body weight, adipose tissue and lean mass increase.
Dietary zinc intake is inversely associated with stunting among adolescent girls in Tanzania
Authors: Chen Shanshan , Ronnenberg Alayne , Cordeiro Lorraine
Published: June 2021

Stunting is a highly prevalent public health problem in developing countries, particularly among populations exposed to food insecurity and chronic malnutrition. Empirical research has shown that early childhood malnutrition is a strong predictor of stunting. Zinc is essential to growth and development, deficiency in this micronutrient may further contribute to stunting in childhood and adolescence. This cross‐sectional study examined the associations between stunting and dietary intake of zinc among a sample of never‐married adolescent girls (n=296) living in Kilosa District, Tanzania. Dietary, anthropometric, physical activity, morbidity and demographic data were collected. The associations between stunting (determined as height by age less than 3rd percentile of WHO reference) and dietary intake of zinc were tested using logistic regression, adjusting for age, socioeconomic status, BMI, energy intake, physical activity and individual dietary diversity. The prevalence of stunting was 62.2%. Adolescent diets were generally deficient in zinc, with a mean intake of 3.4 mg/day compared to the RDA value of zinc intake as 8–9 mg/day for adolescent girls. Higher intake of zinc was found to be associated with lower risk of stunting (OR, 0.872; 95%CI, 0.763–0.998, p<0.05). These findings suggest that dietary intake of zinc may play a significant role in the chronic nutritional status of adolescent girls. Longitudinal studies examining these associations in developing countries settings are needed.

Grant Funding Source : ASN
The effect of agricultural strategies to improve household food production on the health and nutrition outcomes of women and young children: a systematic review
Authors: Girard Amy Webb , Self Julie , McAuliffe Corey , Olude Olafunke
Published: June 2021

Increasing household food production (HHFP) is a common strategy to improve household food security and nutrition in resource‐poor settings. We systematically reviewed the effects of HHFP interventions on the nutrition and health outcomes of women and young children using a modified version of the Child Health Epidemiology Reference Group (CHERG) adaptation of the GRADE technique; 35 studies met inclusion criteria. HHFP interventions improved women's and children's diet diversity, intakes of micronutrient‐rich fruits and vegetables, and intakes of animal‐source foods. HHFP strategies improved vitamin A (VA), protein, energy, and/or iron intakes among women; effects on BMI, VA status and/or anemia were inconclusive. Among children, HHFP consistently improved VA intakes and nonsignificantly reduced stunting by 7%, underweight by 28%, and wasting by 6%; effects on anemia and VA status were mixed. The evidence base for HHFP strategies is limited because most studies are nonrandomized, lack adequate controls, have limited power, and do not use appropriate analytic methods. In conclusion, while strategies to improve HHFP positively impact dietary practices and increase vitamin A intakes, effects on biological and anthropometric indicators of nutrition are unclear. Additional, well designed studies are needed that examine a diverse array of nutrition indicators.
New Therapeutics Targeting Heart Failure: Development of GRK2 Selective Inhibitors
Authors: Homan Kristoff T , Thal David M , Wu Emily , Chen Jun , Sklar Larry , Tesmer John JG
Published: June 2021

Heart failure is a leading cause of death in adults throughout the world. One of the defining characteristics of heart failure is dysregulation of G protein‐coupled receptor (GPCR) signaling, namely that mediated by the β‐adrenergic receptors (βARs). Prolonged stimulation of βARs results in receptor desensitization, which is initiated through phosphorylation by G protein‐coupled receptor kinases (GRKs). It has been demonstrated that inhibition of one of these GRKs, GRK2, improves prognosis in heart failure through increased cardiac performance. Given the therapeutic potential of inhibiting GRK2, considerable effort has been devoted towards developing selective inhibitors. In this work, high‐throughput screening methods were used to identify potential GRK2 inhibitors. One set of related compounds has been identified as potent inhibitors of GRK2 for which structure‐activity relationships are being elucidated. Another inhibitor is a previously approved FDA drug which demonstrated high selectivity for GRK2 in vitro and was efficacious in vivo.

Support was provided by NIH grants HL086865, HL071818, and MH089378.
Applicability of Cable Theory to Vascular Conducted Responses
Authors: Hald Bjørn Olav , Jensen Lars Jørn , Sørensen Preben Graae , Holstein-Rathlou Niels-Henrik , Jacobsen Jens-Christian Brings
Published: June 2021

Conduction processes in the vasculature are usually described using cable theory, i.e. locally induced signals decay passively along the arteriolar wall. The steady state length constant, λ, derived from cable theory quantifies the decay. However, cable theory depends on assumptions not necessarily fulfilled in small arteries and arterioles. We employ a recently developed mathematical model by Kapela et. al 2010 of a rat mesenteric arteriole to investigate if the assumptions hold and whether λ adequately describes simulated conduction profiles.

We find that although many important cable theory assumptions are violated, a phenomenological use of the length constant derived from cable theory is a good measure of conduction length. Hence, λ should be interpreted as a descriptive measure and not in light of cable theory.

Determination of λ using cable theory assumes steady state conditions. In contrast, using the model it is possible to probe how conduction behaves before steady state is achieved. The time‐dependent activation of ion channels leads to changing conduction profiles during this period and may partly explain the different conduction properties of different agonists.
Subendothelial pericytes in the intima of venous bypass grafts catalyze thromboembolic and atherosclerotic processes
Authors: Nees Stephan , Gansera Brigitte , Juchem Gerd
Published: June 2021

Objective

deeper insight into the mechanisms of thrombotic and proliferative occlusion of coronary bypass grafts of venous origin and remedy. Common preparation and intraoperative storage of grafts in usual preservation solutions (such as saline) cause vast endothelial denudation (>50%) and exposure of newly detected subendothelial pericytes (P) of the intima. P express a high tissue factor concentration and form the prothrombinase complex (31±4 nmol Xa bzw. 5.7nmol ± 1.08 Prothrombin •min−1•10−6cells), thus catalysing rapid formation of fibrin thrombi. Following exposure to locally formed serum, P proliferate more rapidly (doubling time <18h). Attached platelets and leukocytes accelerate the procoagulatory and proliferative processes further, and endothelium‐dependent anticoagulatory activities are significantly abolished. In contrast, sealing venous grafts using a custom‐built injector system to prevent pressure artifacts during sealing and storage in a plasma derivative preserve graft endothelialization (>90%) with retention of typical anti‐thrombogenic endothelial activities. Given their general presence in the vascular intima, P may play a hitherto unrecognized role in many thrombotic and sclerotic illnesses. The optimized intraoperative handling techniques described can improve graft prognosis considerably. Supported by a grant of the Friedrich‐Baur‐Stiftung, Munich.
The role of KIR6.2 in mediating NOX2‐derived ROS‐dependent neovascularization in response to ischemic injury
Authors: Browning Elizabeth Anne , Yu Kevin , Hong Nankang , Fisher Aron B , Chatterjee Shampa
Published: June 2021

Acute ischemic injury results from vascular obstruction by pulmonary emboli and peripheral artery disease. Ischemia induces a burst of NADPH Oxidase 2 (NOX2)‐dependent endothelial reactive oxygen species (ROS) crucial for ischemia‐induced neovascularization. We have shown that KIR6.2 regulates NOX2‐derived ROS. An endothelial cell (EC) scratch assay indicated both NOX2‐and KIR‐null ECs migrate 50% slower than WT ECs. We hypothesize KIR6.2 is required for ROS‐mediated post‐ischemic neovascularization. KIR6.2‐and NOX2‐null, wild type (WT), Apocynin (Apo)‐ and Cromakalim (Crom)‐treated mice underwent femoral artery ligation. Doppler and fluorescent microbeads were used to detect macro‐ and microcirculation. NOX2‐and KIR6.2‐null and Crom‐and Apo‐treated mice have 65–80% fewer capillaries indicating reduced angiogenesis. KIR6.2‐null limbs are 35% less perfused at Day 5 but recover suggesting arteriogenesis is reduced less than angiogenesis. NOX2‐null mice have 30% and 25% less perfusion than WT at Days 14 and 21 suggesting that while NOX2‐derived ROS is important for angio‐and arteriogenesis, its regulation by KIR6.2 is crucial for angiogenesis. KIR6.2 contributes to the pathogenesis of diabetes‐related cardiovascular dysfunction thus the link between KIR6.2 and pro‐angiogenic ROS signaling has implications for treatment of diabetes‐related vascular complications. NHLBI‐T32‐S54932
Endoplasmic reticulum stress and diabetic nephropathy
Authors: Shevalye Hanna , Watcho Pierre , Lupachyk Sergey , Obrosova Irina G
Published: June 2021

These experiments evaluated the role for endoplasmic reticulum (ER) stress in prediabetic (PDN) and diabetic (DN) nephropathies. In study 1, control and STZ‐diabetic rats were treated with or without the chemical chaperone trimethylamine‐N‐oxide (TMAO), 110 mg kg−1d−1, for 12 wks. In study 2, C57Bl6/J mice were fed normal or high‐fat (HFD) diets for 16 wks, and then maintained with or without treatment with salubrinal, a selective inhibitor of eIF2alpha dephosphorylation. In study 1, diabetes‐induced renal ER stress was manifested by increased phospho‐PERK, total PERK, and phospho‐PERK/total PERK ratio and by decreased phospho‐eIF2alpha and phospho‐eIF2alpha/total eIF2alpha ratio. CHOP increased by 18%, but the difference with controls was not significant (p=0.073), and BiP remained unchanged. TMAO reduced diabetes‐associated albuminuria, mesangial expansion, fibronectin accumulation, and collagen deposition, without affecting podocyte loss. In the HFD study, salubrinal blunted renal cortex collagen deposition, indicative of the importance of ER stress in PDN. Salubrinal improved HFD‐induced glucose intolerance, without alleviating albuminuria. These findings implicate ER stress in the development of PDN and DN and identify a new therapeutic target.
[Nle3, D‐Phe6]‐gamma melanocyte stimulating hormone (NDP γMSH), increases glomerular filtration rate (GFR) in high salt fed rats
Authors: Healy Vincent , Flanagan Evelyn T , Cope Georgina , Johns Edward J
Published: June 2021

This study examined the cardiovascular and renal actions of the natriuretic peptide γMSH with those of a synthetic analogue, NDP‐γMSH.

Both γMSH and NDP‐γMSH were infused systemically (3–1000 nmol/kg) and intrarenally (500 fmol/min) into innervated and renally denervated normal and high salt fed rats. The effect of the infusion of these peptides on mean arterial pressure (MAP), urinary sodium excretion, urinary output, GFR and fractional sodium excretion was measured.

Both renal and systemic infusion of γMSH increased MAP by 23±2% and 54±4% respectively but no pressor effects were observed upon renal or systemic infusion of NDP‐γMSH. The analogue increased urine flow and sodium excretion by 2–3 fold in fed a normal salt (0.4% Na+) diet and by 6–7 fold in rats fed a high salt (4% Na+) diet and induced a 3.5‐fold increase in GFR in high salt fed rats compared to normal salt fed controls. These renal effects of NDP‐γMSH were not abolished by prior renal denervation.

NDP‐γMSH possessed the natriuretic but not the cardiovascular properties of γMSH. These natriuretic effects occur independently of renal innervation suggesting a direct effect of NDP‐γMSH on the kidney.
Telemetry‐based oxygen sensor to continuously monitor kidney oxygenation in conscious rats
Authors: Koeners Maarten , Ow Pei , Abdelkader Amany , Verhaar Marianne C. , Evans Roger G. , Russell David M. , Joles Jaap A. , Malpas Simon
Published: June 2021

Disturbed kidney oxygenation, i.e. renal hypoxia, may contribute to initiation and progression of both chronic kidney disease and acute kidney injury. A critical barrier to investigate this is lack of methods to chronically measure kidney tissue oxygen. We have developed a novel solution for chronic measurement of oxygen in the kidney. Using a telemetry‐based carbon paste oxygen electrode we continuously recorded kidney oxygenation for 6 weeks in rats, unhindered by anesthesia or restraint. Oxygen values were stable over time with a coefficient of variation (CV) within individual recordings of 16±6% and comparable values between animals; 90±27 μM oxygen. This was in agreement with recordings obtained under anaesthesia with spontaneous respiration; 85±19 μM oxygen and CV: 7±5%. In addition we observed a reproducible response to repeatedly applied changes in inspired oxygen, both in conscious and anesthetized rats. These experiments are the first to monitor renal oxygenation continuously in untethered conscious rats. EU, FP7, Marie Curie Actions, International Outgoing Fellowship.
Liquid medium culture effect on Eucalyptus shoots: growth and development in bioreactor
Authors: Hyodo Vivian Cristina Costa Castilho , Runho Daniela Cristina Scacci
Published: June 2021

The objective of this study was to evaluate the growth of six Eucalyptus clones cultivated in bioreactor containing two different liquid media culture: JADS (Correia et al., 1995) and new liquid medium that was formulated according to minerals nutrients contents of the six clones. The experiment was carried out on a completely randomized statistical design with 12 treatments. Shoots cultivated in semi‐solid JADS medium were transferred to bioreactor RITA containing the new formula of liquid medium and JADS liquid medium as control. After one subculture of 21 days, the fresh weight, the oven dry weight, the relative growth rate and pH value were weekly evaluated for 21 days culture period. Besides, mineral nutrients contents, total soluble non‐structural carbohydrate, total soluble protein were determined at the 21st day of culture. Data were analyzed through principal component analysis (PCA). The first results indicated that the new liquid medium culture promoted greater shoot growth than the ones cultivated in liquid JADS medium for the shoots cultivated in bioreactor, improving its productivity. More studies will be conducted using this new medium formula.
Functional insights into the activation mechanism of Ste20‐ related kinases
Authors: Gagnon Kenneth B , Rios Kerri , Delpire Eric
Published: June 2021

Heterologous expression of sea urchin (Strongylocentrotus purpuratus) OSR1 (suOSR1) cRNA with mouse WNK4 cRNA and mouse NKCC1 cRNA in Xenopus laevis oocytes activated the cotransporter indicating evolutionary conservation of the WNK4‐ OSR1‐NKCC signaling pathway. However, expression of a suOSR1 kinase mutated to confer constitutive activity did not result in stimulation of the cotransporter. Using a chimeric strategy, we determined that both the mutated catalytic and regulatory domains of the suOSR1 kinase were functional, suggesting that the tertiary structure of full‐length mutated suOSR1 must somehow adopt an inactive conformation. In order to identify the regions or residues which lock the suOSR1 kinase in an inactive conformation, we created and tested several additional chimeras. Coexpression of these chimeras identified several regions in both the catalytic and regulatory domain of suOSR1 which prevented the kinase from acquiring an active conformation. Interestingly, non‐functional suOSR1 chimeras were able to activate mouse NKCC1 when a mouse scaffolding protein, Cab39, was co‐expressed. Chimeras and kinase stabilization with mouse Cab39 has provided some novel insights into the activation mechanism of the Ste20‐related kinases.
Disease causing mutations affect ENaC gating
Authors: Kucher Volodymyr , Boiko Nina , Stockand James D.
Published: June 2021

Gain and loss‐of‐function mutations in the epithelial Na channel (ENaC) affect renal Na+ excretion. Here, we identify five mutations in ENaC that lead to changes in single channel properties, and should be informative about structure‐function relations within the channel protein. Channels containing the PHA‐I mutation, G37S in β‐ENaC, are voltage‐dependent where Po is low at physiological potentials. This critical Gly is in a conserved HG motif in the cytosolic NH2‐terminus key to gating. Another PHA‐I mutation, the KYS106‐108‐>N substitution in γ‐ENaC, also markedly decreases current by decreasing Po in a voltage‐dependent manner. The PHA‐I mutation, S562P in γ‐ENaC, results in complete loss of function. S562 occupies a critical position in the selectivity filter of the channel pore possibly being involved in coordination of the conductive ion during permeation. The N530S Liddle's mutation in the γ‐subunit of ENaC replaces a conserved (in ENaC) Arg within the extracellular vestibule of the pore one position downstream of the Deg site. Channels containing γ‐ENaC harboring the N530S substitution have increased Po. The Liddle's mutation W493R in α‐ENaC increases channel activity and Po. W493 also is located in extracellular mouth of the pore and is believed to interact in an electrostatic manner with the key pore residue R492. Notabely, none of these mutations affected single channel conductance.
Identification, localization, and electrophysiologic characterization of small Ca2+‐sensitive K+ channels in cardiac mitochondria
Authors: Gadicherla Ashish Kumar , Camara Amadou KS , Kwok Wai-Meng , Zhou Yifan , Stowe David F
Published: June 2021

It is now well recognized that protective strategies against cardiac ischemia reperfusion (IR) injury involve not only activating cytosolic and mitochondrial factors but also attenuating deleterious mitochondrial (m) factors like excess reactive O2 species (ROS) and excess mCa2+loading. We showed previously that activation of the big Ca2+sensitive K+ channel with NS1619 improved function and decreased levels of ROS and mCa+ after IR injury; it was not known if cardiac myocyte mitochondria were targets of the drug. We also recently found that DCEBIO, a small Ca2+‐sensitive K+ channel (SKCa) agonist, exerts protective effects similar to NS1619. Here we used a multi‐modal approach to determine if the SKCa is indeed present and functional in cardiac mitochondria. After percoll gradient purification of mitochondria we used immuno‐histochemical localization of SKCa, western blot detection and isoelectric focusing (IEF) to seek to identify and localize the channel. Protein fractions from IEF identified as SKCa were then incorporated into planar lipid bilayers to measure channel activity. We found that SKCa was localized to mitochondria and exhibited functional channel activity (conductances of 230, 730 pS in 200 mM KCl) that were blocked by apamin, a blocker of SKCa channels. These studies point towards the presence of SKCa channels in mitochondria and their potential role in cardioprotection against IR injury.
Activation of nucleus tractus solitarii (nTS) neurons that project to the rostral ventrolateral medulla (RVLM) or hypothalamic paraventricular nucleus (PVN): Role of acute hypoxia (AH)
Authors: Ruyle Brian C , Heesch Cheryl M , King T Luise , Kline David D , Hasser Eileen M
Published: June 2021

The nTS integrates chemoafferent input regarding blood oxygen levels and sends projections to the RVLM and PVN. The relative activation by AH of the nTS‐RVLM versus the nTS‐PVN pathway is unknown. We hypothesized that the nTS‐PVN pathway is relatively inactive during mild‐moderate AH but increases its activity with severe AH, while the nTS‐RVLM pathway is maximally activated by mild‐moderate hypoxia. Retrograde tracers were microinjected into the PVN or RVLM to identify nTS neurons that project to these regions. Following recovery, conscious rats were subjected to Normoxia (21% O2) or AH (12 or 10% O2). We used Fos‐immunoreactivity (IR) as an index of neuronal activation and Tyrosine Hydroxylase (TH)‐IR to identify catecholaminergic neurons. AH produced an intensity‐dependent increase in ventilation and Fos‐IR in nTS cells (O2: 21%, 10±4; 12%, 54±14; 10%, 100±28 cells). Increasing AH severity (from 12% to 10% O2) increased the percentage of activated nTS‐PVN cells but not nTS‐RVLM cells. Very few nTS‐RVLM cells (4±1%) were TH‐IR. In contrast, 40±7% nTS‐PVN cells were TH‐IR; Fos‐IR in these neurons increased with AH severity. Results suggest AH progressively increases the activity of nTS‐PVN neurons; many of these cells are catecholaminergic. In contrast, nTS‐RVLM neurons are activated by mild‐moderate AH and undergo little further activation with increased severity of hypoxia. Multi‐Investigator HL98602
Peripheral Chemoreceptors Contribute Significantly to Hypertension in Spontaneously Hypertensive Rats (SHR)
Authors: Whiteis Carol A. , Post Collin E. , Morgan Donald A. , Rahmouni Kamal , Chapleau Mark W. , Abboud Francois M.
Published: June 2021

In carotid body glomus cells of young pre hypertensive SHR the overexpression of acid sensing ion channels increases their pH sensitivity and is associated with increased sympathetic nerve activity (Tan et al., Circ. Res. 2010). Here we tested the hypothesis that early resection of the carotid bodies might reduce hypertension in SHR. Under anesthesia both carotid bodies were resected (CBX) in young (<5 weeks) SHR and in their normotensive control WKY. Arterial blood pressure (BP) recorded using a tail cuff twice a week over a 5 month period was lower in SHR with CBX than in sham‐operated SHR (p<0.05 ANOVA). The 24 hour intra‐arterial BP recordings in awake rats at 23 weeks of age are below.

Systolic BP (mmHg)
Mean BP (mmHg)

Sham
CBX
Sham
CBX

WKY
149±5 (n=5)
146±6 (n=6)
120±5
119±7

SHR
239±6* (n=10)
202±8*† (n=9)
185±3*
159±6*†

p<0.05 (SHR vs. WKY)

p<0.05 (CBX vs. Sham)

Compared to WKY, the mean BP was 65±3 mmHg higher in SHR‐Sham and only 40±6 mmHg higher in SHR‐CBX. Under anesthesia ventilatory and renal nerve activity responses to chemoreceptor stimulation were measured. The left ventricular (LV) weight of SHR‐Sham (1.04±0.03 gm) was significantly greater (p<0.002) than that of SHR‐CBX (0.92±0.01) and WKY (0.91±0.01).

Conclusion

The contribution of the hypersensitive peripheral chemoreceptors to the increase in mean BP in SHR is estimated to be 38% and may account for most of the LV hypertrophy. (NIH/HL14388)
Contribution of PIN in the regulation of neuronal nitric oxide synthase in the PVN of Rats with chronic heart failure
Authors: Sharma Neeru , Llewellyn Tamra , Zheng Hong , Patel Kaushik P
Published: June 2021

Expression of neuronal nitric oxide synthase (nNOS) decreased in the paraventricular nucleus (PVN) of rats with chronic heart failure (CHF), however the molecular mechanism remains unclear. In the present study protein levels of PIN (a protein inhibitor of nNOS, known to dissociate nNOS dimers into monomers) increased (1.12±0.09 vs. Sham 0.76±0.10) with approximately 60% decrease in dimer/monomer ratio in the PVN of rats with CHF (6–8 wks. after coronary artery ligation). In vitro studies using neuronal cell line, NG108 showed that PIN protein expression is 2.3‐ fold higher in response to angiotensin II (Ang II). Silencing of PIN in NG108 cells leads to 2‐fold accumulation of nNOS suggesting a regulatory role of PIN in NO synthesis. Moreover, dimer/monomer ratio of nNOS also increased by 80% with PIN knockdown in NG108 cells. Furthermore, Ang II treatment in NG108 cells in the presence of proteasome inhibitor, lactacystin, led to decreased ubiquitination of PIN (54% decrease vs. lactacystin alone), suggesting that posttranslational processes such as protein degradation/stabilization are involved in Ang II dependent upregulation of PIN. We conclude that post‐translational accumulation of PIN, mediated by Ang II, leads to a decrease in the dimeric active form of nNOS as well as protein levels of nNOS which may lead to reduced nitric oxide mediated inhibition of sympathetic tone during CHF. Supported by NIH grant HL62222
Hepatocyte nuclear factors 1α and 1β (HNF1α and HNF1β) are powerful inducers of the enzymatic activity of angiotensin‐converting enzyme 2 (ACE2) in insulin‐secreting cells
Authors: Pedersen Kim Brint , Lazartigues Eric
Published: June 2021

Maturity onset diabetes of the young (MODY) types 3 and 5 are caused by deficiency of hepatocyte nuclear factor 1α (HNF1α) and hepatocyte nuclear factor 1β (HNF1β) which bind to similar DNA motifs. Our laboratory has previously shown that: 1) pancreatic angiotensin‐converting enzyme 2 (ACE2) is reduced in diabetes, 2) pancreatic ACE2 gene therapy improves glucose control in diabetic mice, and 3) HNF1β induces expression of ACE2 mRNA in insulinoma cells. However, discordance between ACE2 expression at the mRNA and enzyme activity level is often reported. Furthermore, HNF1α is more prevalent and thought to be more important than HNF1β in differentiated beta cells. Hypothesis: Both HNF1α and HNF1β lead to increased ACE2 mRNA expression as well as elevated ACE2 enzymatic activity in insulin‐secreting cells. Transfection of rat 832/13 insulinoma cells with expression plasmids for HNF1α and HNF1β led to marked (25‐ and 95‐fold, respectively, p < 0.001) induction of ACE2 mRNA and a strong increase (12‐ and 41‐fold, p < 0.001) in ACE2 enzymatic activity. Furthermore, HNF1α and HNF1β induced expression from both of the two known ACE2 promoter regions in mouse βTC‐3 insulinoma cells. The data demonstrate a link between HNF1α/HNF1β, ACE2 activity, and glucose homeostasis. These observations could lead to new therapeutic strategies for the treatment of MODY and type 2 diabetes. Support: NIH/NIDDK (DK084466).
Non‐peptide Agonist of the Receptor MAS, AVE 0991, Increases PPARα Expression in Muscle of Rats Fed Fructose‐ Rich Diet
Authors: Mario Érica Guilhen , Santos Robson , Botion Leida Maria
Published: June 2021

The aim of the present study was to evaluate the role of AVE 0991, agonist non‐peptide of Angiotensin‐(1–7), in lipidic profile of Sprague‐Dawley male rats. Animals were randomly distributed into fed commercial diet plus 10% fructose in drinking water during 3 weeks, after animals were treated with (FA) or without (F) 1 mg/Kg AVE0991 during 2 weeks. To evaluate the effects of AVE, it was analyzed: serum biochemical parameters, activity of lipoprotein lipase (LPL) in muscle and gene expression of PPARγ, SREBP‐1c and PPARα by real time PCR. Treatment with AVE0991 promoted reduction in serum levels of free fatty acids (F 0.707±0.02mmol/L vs. FA 0.558±0.06mmol/L) and triacylglycerol (F 163.9±18.18mg/dL vs. FA 108.7±11.65mg/dL) without altering the levels of total cholesterol in animals fed with fructose. The activity of LPL in muscle was increased (F 0.014±0.005mU vs. FA 0.04±0.01mU) without changing gene expression of PPARγ and SREBP‐1c. However, there was an increase in gene expression of PPARα (F1.1±0.14 unit arbitrary vs. FA 5.4±1.8 unit arbitrary). These data suggest that treatment with AVE0991 increased the consumption of lipids by muscle, and this can contribute to the reduction of free fatty acids and triacylglycerol found in serum of rats fed a fructose‐rich diet.

Financial support: CNPq, CAPES, FAPEMIG.
Perceptions of second year medical students to interactive tools, games, and audience response systems incorporated to teach pharmacology
Authors: Gorman A. Laurel , Berry Andrea
Published: June 2021

Second year medical students were surveyed to determine perceptions of the effectiveness of innovative, interactive methods employed to teach pharmacology in clinically integrated, systems‐based modules.

METHODS

Interactive techniques included clicker audience‐response questions, game‐based competitions, and interactive automated slides completed with audience participation. An anonymous survey was distributed to students assessing perceptions of the techniques in encouraging engagement, knowledge acquisition, and critical thinking. Observations of student participation were made comparing traditional sessions with more interactive sessions.

RESULTS

Students had very positive perceptions of interactive techniques, consistently agreeing or strongly agreeing that they promoted classroom engagement, encouraged critical thinking/group discussion, and increased interest in learning pharmacology. Observations included an increase in the number of student‐generated questions as well as a wider distribution of students participating in the interactive sessions.

CONCLUSIONS

Second year medical students perceived that incorporation of interactive exercises and clicker‐style games into pharmacology sessions were effective learning tools that promoted engagement, interest, and critical thinking about pharmacology concepts.
A Virtual Pharmacology Course in a PBL Curriculum
Authors: Karpa Kelly
Published: June 2021

Providing medical students with a solid foundation in pharmacology (pharm) can be challenging within the confines of an intensive problem‐based learning (PBL) curricula. To address deficits uncovered at our medical school, a pharm educator was hired in 2002 and a variety of methodologies were used to fill curricular gaps. We evaluated the curricular enhancements and outcomes that have resulted. To accomplish this goal, we reviewed course syllabi, learning objectives from lectures, course examinations, and United States Medical Licensing Examination (USMLE) Step 1 scores for academic years 2002–2003 and 2009–2010. Our analysis revealed a non‐significant increase in didactic pharm lectures in most courses, albeit a more structured learning environment with more pharm learning objectives (P<0.001). Additionally, students are incentivized to study PBL‐based pharm as the number of pharm questions on course examinations has increased (P<0.001). Analysis indicates that students who regularly attend recently‐implemented voluntary pharm review sessions score higher on USMLE Step 1 (P=0.038); of, course, this may reflect self‐selection bias. Our balanced, thoughtful and deliberate attention to pharm education is particularly important in an integrated, organ‐based, and significantly PBL‐driven curriculum.
Building and Sustaining Interdisciplinary STEM: What Works from the Keck/PKAL Facilitating Interdisciplinary Learning in Science and Mathematics Project
Authors: Schlegel Whitney M , Stewart Mark T , Ridgway Judith S , Roth Mary JS , Elrod Susan
Published: June 2021

Interdisciplinary learning (IDL) supports student motivation to learn science by providing a rich context for understanding and encouraging opportunities for the application of abstract concepts from multiple fields. IDL enhances student general knowledge of science and its intersections and relevance to society while also improving the ability of students to engage with complexity (NRC, 2011). Implementing interdisciplinary courses and curricula has proven hard work and can be daunting within institutional cultures that are deeply entrenched in disciplinary traditions. The Keck/Project Kaleidoscope (PKAL) Facilitating Interdisciplinary Learning Project [FIDL] began in 2007 and engaged 28 campus teams in sharing the experience of building and sustaining interdisciplinary programs in science and mathematics. The shared campus experiences during the three years of the project provided for five recommendations and offered strategies for successful mobilization, implementation, and institutionalization of interdisciplinary programs (AAC&U/PKAL, 2011). Campus case studies will illustrate the process and recommendations for facilitating interdisciplinary undergraduate science at different institutional types.
MATTERS OF TASTE: BLENDING MOLECULAR PHYSIOLOGY AND THE HUMANITIES
Authors: Rangachari Patangi K , Rangachari Usha
Published: June 2021

Taste perception was the focus of an undergraduate course in the health sciences that bridged the sciences and the humanities. A problem‐based learning (PBL) approach was used to deal with the biological issues whereas the cultural transmutations of these molecular mechanisms were explored using a variety of sources (novels, cook‐books, films). Multiple evaluation procedures were used; problem summaries and problem‐solving exercises (TRIPSEs) for the PBL component and group tasks and individual exercises for the cultural issues. Self‐selected groups chose specific tasks from a prescribed list (setting up a journal in molecular gastronomy, developing an electronic tongue, organizing a farmer's market or a culinary tour, framing hedonic scales etc). Individual tasks were selected from a menu of options (book reviews, films reviews, conversations, creative writing). A few guest lecturers (wine making, cultural anthropology) added more flavor. The course was rated highly for its learning value (8.95 ±1.02, n=36) and helped students relate biological mechanisms to cultural issues (8.3 ± 1.38, n=35).
Sex and Racial Population Differences in the Arthro‐kinematics of the Carrying Angle: Potential Clinical Implications
Authors: Baral Sumit , Elnekaveh Brandon M. , Adar Tony , Pagano Anthony S. , Marquez Samuel
Published: June 2021

The carrying angle (CA) of the elbow is defined as the angle between the long axis of the extended forearm as it lies lateral to the long axis of the arm. It develops in response to pronation of the forearm and keeps the swinging upper extremity away from the side of the pelvis during locomotive gait. Larger CA's may be a risk factor leading to elbow instability and pain. This study compares the CA between males and females and between Euro‐Americans (EA) and African Americans (AA). 10 male (5 EA, 5 AA) and 10 female (5 EA, 5 AA) volunteers drawn from an urban population with no past history of elbow pathology had their CA's measured via goniometer. Results showed that males had an average CA of 12.32 degrees compared to an average 15.08 degrees in females. EA and AA had less discrepant angles of 13.68 degrees and 13.72 degrees, respectively. Student's t‐test revealed that the angles of females were significantly (p<0.05) larger than those of males, while no significant variation was shown in the angles between EA and AA. The cultural role of females in rearing children typically involve the carrying of their young, which generates a significant amount of stress on the proximal muscle attachments of the medial and lateral epicondyles of the elbow. Our results suggest that CA may be a predisposing factor of the female predilection to epicondylitis particularly in eccentric contraction during routine activities.

Grant Funding Source: SUNY Downstate College of Medicine Alumni Association
THE SURGICAL IMPORTANCE OF THE BLOOD SUPPLY OF THE TIBIA
Authors: Shaibah Hassan S , Altaf Faris Altaf M
Published: June 2021

The objectives were

to study the blood supply to the tibia to show its possible use as vascularized bone allograft.

Materials and Methods

20 lower limbs of both sexes and both sides. The femoral artery of each cadaver was injected with red latex in lead oxide. The tibia was dissected to show its blood vessels.

Results

The tibia was supplied by vascular circles made essentially by the periosteal branches of the anterior tibial artery which was supported by periosteal branches from the inferior genicular arteries at the upper fourth of the tibia. In the following fourth, the periosteal branches of the posterior tibial artery and the nutrient artery support the anterior tibial artery. At the next fourth (distal diaphysis), these circles were made only by the periosteal branches of the anterior tibial artery while at the distal fourth, the vascular circles were made by periosteal branches of the anterior and posterior tibial arteries and the peroneal artery. The nutrient artery of the tibia originated from the posterior tibial artery.

Conclusion

Tibia has a rich blood supply with sizable feeding vessels; the anterior and posterior tibial and the nutrient arteries. It can be used as free vascularized bone allograft. Its richly supplied periosteum can be used as vascularized periosteal allograft to treat nonunion fractures.

Grant Funding Source: N/A
Pelvic Reproductive Organ Vasculature in Boars
Authors: Freeman Larry E.
Published: June 2021

Casts of pelvic vasculature were prepared by perfusion with Batson's compound via the abdominal aorta in post mortem specimens of sexually mature male pigs to clarify patterns of vascular supply of the reproductive organs. Reported here are the features revealed for the male reproductive organs within the pelvic cavity, specifically, the accessory sex glands, and the root of the penis at the pelvic outlet. Casts revealed details including a blood supply for the vesicular glands, prostate, and much of the bulbourethral glands from branches of the prostatic arteries. Each massive, elongated bulbourethral gland received blood supply from two sources. Branches from the prostatic artery entered the cranial end of the gland and supplied approximately two thirds to three fourths of its mass. The remaining caudal portion of the bulbourethral gland received branches off the caudal extent of the internal pudendal artery, just proximal to the branching of the artery of the penis. The artery of the penis sent multiple small branches (arteries of the bulb) into the large penile bulb at the proximal end of the corpus spongiosum penis, a few small branches (deep arteries of the penis) into the crus of the penis, and a dorsal artery of the penis that coursed along the penile body.
Epicardial HIF1 regulates vascular precursor cell invasion into the myocardium through the VEGF signaling pathway
Authors: tao jiayi , Doughman Yongqiu , Yang Ke , Ramirez-Bergeron Diana , Watanabe Michiko
Published: June 2021

During cardiogenesis, a subset of epicardial cells undergoes epithelial‐mesenchymal‐transition (EMT) and the resulting epicardial derived cells (EPDC) migrate into the sub‐epicardium and myocardium and differentiate into several cell types of the coronary vasculature. Our previous data suggested a link between HIF and epicardial EMT and further coronary vasculogenesis. To better understand the autocrine role of HIF in the epicardium, we used an adenoviral system to constitutively express active HIF1a in the embryonic quail epicardium. We observed that over‐expression of HIF1a in the epicardium prevented EPDC from proper migration into the myocardium. In vitro collagen gel assays confirmed that infection with AdcaHIF1a impaired the invasiveness of epicardial cells. Results from immunostaining and real‐time PCR revealed that epicardial EMT and differentiation of EPDC into endothelial cells and smooth muscle cells were not disrupted. Further investigation suggests that the increase in VEGFR1 expression caused the inhibition of EPDC invasion. In conclusion, our studies support the hypothesis that epicardial HIF is required for regulating epicardially derived mesenchyme invasion into the myocardium, a critical step in the vascularization of the myocardium. This role of HIF suggests that the differentially hypoxic microenvironment may inform epicardial cells when to stop or start migration.

Grant Funding Source: American Recovery and Reinvestment Act (ARRA) R01HL091171
NMD‐deficient Upf3b‐null mice display behavioral and neuropathological defects
Authors: Huang Lulu , Shum Eleen Y. , Karam Rachid , Nguyen Lam Son , Gecz Jozef , Wilkinson Miles F
Published: June 2021

To address the physiological role of nonsense‐mediated RNA decay (NMD), we generated mice with a null mutation in the Upf3b NMD gene. While these Upf3b‐null mice are viable, fertile, and grossly normal, a battery of behavioral tests revealed they exhibit a specific defect in sensorimotor gating. This defect is commonly displayed in Schizophrenia patients, a subset of whom have recently been shown by several groups to have mutations in the human UPF3B gene. Neuropathological examination of the frontal cortex, the site responsible for sensorimotor gating, revealed decreased dendritic spine density and mature dendritic spines in pyramidal cells. Intriguingly, such defects are also observed in schizophrenic and autistic patients. To understand the underlying mechanisms by which UPF3B acts in this circuit, we performed exon‐array analysis of the frontal cortex of Upf3b‐null mice. This revealed dysregulation of several mRNAs transcribed from genes mutated in intellectual disability patients, most of which encode proteins that function in sensory perception and cognition. NMD is likely to have a direct role in regulating many of these transcripts, as most have “NMD‐inducing features.” We propose that Upf3b‐null mice are a useful model system to understand the underlying mechanism of sensorimotor gating and how it is disrupted in Schizophrenia patients.

This study was supported by the NIH.
The mechanism of oxygen activation by Pea Seedling Amine Oxidase
Authors: Sommer Dayn Joseph , Choi Eunah , Bitsimis Alexandra , Chow Courtney , Mills Stephen
Published: June 2021

Copper Amine Oxidases (CAOs) are a large family of enzymes that catalyze the oxidation of primary amines to aldehydes and ammonia, with concomitant reduction of O2 to H2O2. These enzymes utilize two cofactors to accomplish this reduction, topaquinone (TPQ) and a Cu(II) ion. Catalysis occurs through ping‐pong kinetics in two half‐reactions, a reductive half‐reaction and an oxidative half‐reaction. Two mechanisms have been proposed for the oxidative half‐reaction. In one mechanism (indirect electron transfer), an electron is initially transferred from the TPQ cofactor to Cu(II), forming Cu(I). Molecular oxygen can then bind reversibly to Cu(I) for catalysis to proceed. In a second mechanism (direct electron transfer), the TPQ cofactor transfers an electron directly to a prebound oxygen molecule, with no reduction of the Cu(II). To study which of the proposed mechanisms PSAO uses, the active site Cu(II) was replaced with Co(II) and the kinetics of CoPSAO were studied. Since Co(II) cannot be reduced to Co(I) in a protein, the indirect electron transfer mechanism is blocked. If PSAO uses the indirect mechanism, it will not be active with Co(II) in the active site. If PSAO is active with Co(II) in the active site, then it likely uses the direct mechanism. CoPSAO showed a 95% decrease in kcat, indicating a strong preference for the indirect electron transfer mechanism. This work was supported by the University of San Diego.
Salt‐inducible kinase 1 links p300 phosphorylation to CREB regulated gluconeogenesis post burn
Authors: Brooks Natasha C , Smith Alexandra H , Hiyama Yaeko , Finnerty Celeste C , Herndon David N , Boehning Darren , Jeschke Marc G
Published: June 2021

Severe burn injury results in sustained catecholamine release and increased cyclic AMP (cAMP) levels. cAMP‐induced inhibition of salt‐inducible kinase 1 (SIK1) has been shown to promote recruitment of the transcriptional co‐activator p300 to cAMP response element binding protein (CREB), resulting in gluconeogenesis. Gluconeogenesis is increased and maintained post‐burn injury yet the molecular mechanism is unknown. We hypothesize that catecholamine‐induced inhibition of SIK1 resulting in increased p300 transcriptional activity sustains gluconeogenesis. The 60% total body surface area burn model on rats was employed as a model system. The catecholamine surge during burn injury led to the inhibition of SIK1, increased blood glucose levels, and increased p300 mediated transcription of CREB‐regulated gluconeogenic genes. Restoration of SIK1 activity by administration of propranolol, a non‐selective β1/2 adrenergic receptor antagonist, resulted in inhibition of p300‐ mediated transcription and decreased blood glucose levels. We conclude that catecholamine release after severe burn injury leads to inhibition of SIK1, resulting in sustained gluconeogenesis.

This work was supported by grants from Shriners Hospitals for Children and (SHG 8660 and 6840) the National Institute of Health (RO1‐ GM087285‐0182)
Phosphorylation of argininosuccinate synthase at T131 correlates with changes in NO production
Authors: Pendleton Laura C , Haines Ricci J , Corbin Karen D , Eichler Duane C
Published: June 2021

The citrulline‐nitric oxide cycle is a tightly regulated system for the production of nitric oxide (NO) in vascular endothelial cells. Argininosuccinate synthase (AS) acts as the rate‐limiting step in the cycle which converts citrulline back to arginine, providing the essential substrate for endothelial nitric oxide synthase. Previous work has demonstrated that AS is a phospho‐protein, a post‐translational modification that allows AS to support acute changes in NO production. Bioinformatic analysis identified a putative AS phosphorylation site at threonine 131, which was confirmed by LC‐MS analysis showing that phosphorylation at T131 increased upon treatment of endothelial cells with the serine/threonine phosphatase inhibitor okadaic acid. To investigate the role of phosphorylation of AS at T131, analysis was carried out comparing the overexpression of phospho‐null (T to A) and phospho‐mimetic (T to D) mutations to wild type AS. After knockdown of endogenous AS by siRNA, rescue of AS function was measured by the recovery of NO production in endothelial cells under conditions of limited arginine. Expression of the phospho‐null mutation showed similar levels of NO production to wild type AS. However, expression of the T131 phospho‐mimetic AS construct demonstrated reduced NO upon stimulation with VEGF confirming the physiological significance of T131 phosphorylation. (NIH RO1 HL083153‐01A2).