bluuebunny/crossref_metadata_2025 huggingface dataset:
Common Laboratory Chow Diets Differentially Affect Energy Homeostasis and Modify Metabolic and Electrolyte Balance Effects of DOCA‐salt in Wildtype Mice
Authors: Patil Chetan N. , Oliveira Vanessa , Balapattabi Kirthikaa , Hei Megan Vande , Saravia Fatima , Wackman Kelsey , Reho John J. , Kirby John R. , Sigmund Curt D. , Grobe Justin L.
Published: April 2020

Roughly 27% of humans with essential hypertension (HTN) exhibit low circulating renin, and this condition is experimentally modeled by subcutaneous administration of deoxycorticosterone acetate (DOCA) and high dietary sodium (the DOCA‐salt model). The quantitative effects of DOCA‐salt upon blood pressure, renal function, and energy homeostasis differ in literature reports, due to methodological differences including varied use of uninephrectomy or limiting animals to only saline drinks, with or without potassium supplementation. Here, we examined the hypothesis that the effects of DOCA‐salt on metabolic and electrolyte endpoints would be modified by diet. Male C57BL/6J mice (Jackson Labs; weaned onto LabDiet 5K52) arrived at 6 weeks of age and were immediately randomly placed onto either LabDiet 5L0D (24.1% protein, 5.2% fiber, 0.17 mEq Na/g, 2.89 kcal/g), Teklad 2920 (19.1% protein, 2.7% fiber, 0.043 mEq Na/g, 3.10 kcal/g), or Teklad 7913 (18.0% protein, 4.0% fiber, 0.130 mEq Na/g, 3.10 kcal/g), and offered autoclaved, deionized water to drink in single‐housing conditions (n=16 each). After 3 weeks, body mass differed by diet (5L0D: 3.13±0.31, 2920: 3.61±0.28, 7913: 2.48±0.16 g (mean±sem); p<0.05 by ANOVA) despite the observation that total daily caloric absorption rates (by bomb calorimetry) were similar across groups (14.6±0.3, 14.9±0.6, 14.7±0.2 kcal/d). Mice then underwent sham surgery and were maintained on assigned chow and water (n=8/diet), or were implanted with a subcutaneous 50 mg pellet of DOCA (Sigma) and offered 0.15 M NaCl drink in addition to assigned chow and water (n=8/diet). Expected major effects of DOCA‐salt (eg – to increase Na & fluid intake, urine volume, plasma Na & BUN, and renal mass while decreasing plasma K & Cl, all p<0.05) were observed in all diet groups. As hypothesized, diet significantly modified many effects of 3 weeks of DOCA‐salt (2‐way ANOVA, followed by Sidak multiple‐comparisons procedure), including: body mass (decreased (p<0.05) with DOCA‐salt on 5L0D, vs no change on 2920 or 7913), adipose masses (eg; interscapular “brown” fat mass increased (p<0.05) with DOCA‐salt on 7913, vs no change on 5L0D or 2920), total daily Na intake and urine volume (larger increases with DOCA‐salt on 5L0D vs 5L0D or 2920). We conclude that various common laboratory chow diets have significantly different effects upon aspects of energy balance and electrolyte homeostasis, and that maintenance on these different diets can quantitatively modify the effects of DOCA‐salt in mice.

Support or Funding Information

HL134850, HL084207
Exercise training prevents obesity/diabetes‐induced activation of inflammatory signaling in rat brown adipose tissue
Authors: Tsuzuki Takamasa , Yoshihara Toshinori , Iwawaki Mayu , Murai Katsuyuki , Tamashiro Asuka , Nakai Natsumi , Negishi Takayuki , Yukawa Kazunori , Naito Hisashi
Published: April 2020

Brown adipose tissue (BAT) plays a crucial role in energy expenditure and is recognized as a therapeutic target in metabolic diseases. Chronic inflammation is a common etiology of obesity and type 2 diabetes. A previous study reported increased inflammation in BAT from obese animals. Regular exercise is an effective tool for improving obesity; however, it remains unclear whether exercise training affects the inflammation in BAT from obese animals.

Purpose

To examine the effects of exercise training on the activation of inflammation‐related signaling in BAT from obese/diabetic rats.

Methods

Male Otsuka Long‐Evans Tokushima Fatty (OLETF) rats, a rodent model for obesity/diabetes, were randomly assigned to either sedentary (n = 11) or exercise training (n = 8) groups. Long‐Evans Tokushima Otsuka (LETO; n = 9) rats were used as the non‐diabetic sedentary control. Exercise training on the treadmill was conducted 4 days/week for 20 weeks from 5 weeks of age. An intraperitoneal glucose tolerance test was performed and interscapular BAT was dissected, and phosphorylation levels of inflammatory‐related proteins, as well as the expression levels of mitochondrial proteins, were determined by western blot analysis.

Results

The phosphorylation levels of p65 (a subunit of NF‐κB) and mitogen‐activated protein kinases (MAPK; p38, ERK1/2, and SAPK/JNK) in the BAT were significantly higher in the sedentary OLETF rats when compared to those in the LETO rats. Exercise training attenuated the increase in the phosphorylation levels of NF‐κB and MAPKs in the BAT from the OLETF rats. Moreover, the expression levels of UCP‐1 and ‐3 and oxidative phosphorylation‐related proteins (NDUFB8, SDHB, UQCRC2, MTCO1 and ATP5A) in the BAT were significantly lower in the sedentary OLETF rats than the LETO rats, but exercise training did not alter this.

Conclusion

Exercise training prevents obesity‐induced activation of NF‐κB and MAPK signaling in BAT from obese/diabetic rats.

Support or Funding Information

This work was supported by grants from the MEXT‐Supported Program for the Strategic Research Foundation at Private Universities (S1101008) and a Grant‐in‐Aid for JSPS Fellows (13J10819).
Maternal Glyphosate Exposure Causes Autism‐like Behaviors in Offspring through Increased Expression of Soluble Epoxide Hydrolase
Authors: Pu Yaoyu , Yang Jun , Chang Lijia , Qu Youge , Wang Siming , Zhang Kai , Xiong Zhongwei , Zhang Jiancheng , Tan Yunfei , Wang Xingming , Fujita Yuko , Ishima Tamaki , Hwang Sung Hee , Hammock Bruce D. , Hashimoto Kenji
Published: April 2020

The number of children with autism spectrum disorder (ASD) has increased dramatically since the 1980s. Epidemiological studies suggest that exposure to pesticides (i.e., glyphosate) during pregnancy might increase the risk for ASD in offspring. Recently, we demonstrated that soluble epoxide hydrolase (sEH) in the metabolism of polyunsaturated fatty acids plays a key role in the development of ASD in offspring after maternal immune activation. In the present study, we found ASD‐like behavioral abnormalities in juvenile offspring after maternal glyphosate exposure. Furthermore, we found higher levels of sEH in the prefrontal cortex (PFC), hippocampus, and striatum of juvenile offspring after maternal glyphosate exposure. Oxylipin analysis showed decreased levels of epoxy‐fatty acids
(i.e., 8(9)‐EpETrE [8,9‐epoxy‐5Z,11Z,14Z‐eicosatrienoic acid] in the blood, PFC, hippocampus, and striatum of juvenile offspring after maternal glyphosate exposure, supporting increased activity of sEH in juvenile offspring. The 16S rRNA analysis demonstrated abnormal composition of gut microbiota in fecal samples of juvenile offspring after maternal glyphosate exposure. Interestingly, oral administration of TPPU to pregnant mothers from E5 to P21 could prevent social interaction deficits, increased grooming time in the juvenile offspring after maternal glyphosate exposure. These findings suggest that maternal glyphosate exposure causes ASD‐like behavioral abnormalities and abnormal composition of gut microbiota in juvenile offspring, and that increased activity of sEH plays a key role in ASD‐like behaviors in offspring after maternal glyphosate exposure. Therefore, sEH would represent a promising prophylactic target for ASD in offspring after maternal glyphosate exposure.

Support or Funding Information

This study was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (to K.H., 17H04243), AMED (to K.H., JP19dm0107119), the National Institute of Environmental Health Sciences (NIEHS) R01 ES002710 (to B.D.H.), NIEHS Superfund Program P42 ES004699 (to B.D.H.).
Neuritogenic signal pathway of tPA mediated by the multimolecular complex containing PrPC and LRP1 is dependent on lipid rafts
Authors: Martellucci Stefano , Manganelli Valeria , Santilli Francesca , Mei Cecilia , Ferri Alberto , Mantuano Elisabetta , Garofalo Tina , Sorice Maurizio , Misasi Roberta , Mattei Vincenzo
Published: April 2020

Lipid rafts are signaling microdomains enriched in glycosphingolipids, cholesterol, tyrosine kinase receptors, mono‐ or heterotrimeric G proteins and GPI‐anchored proteins. This dynamic assemblage of several components dissociate and associate rapidly forming, in cell membranes, functional clusters which provide highly efficient lipid–protein modules operating in membrane trafficking and cell signaling. Indeed, lipid rafts are thought to function as platforms that sequestrate specific proteins, permanently or transiently, thus introducing and modulating cell signaling. The combinatorial possibilities offered by the wide range of lipid isoforms, glycan structures, and actin dynamics, attributes an extraordinary assortment of possibilities for receptor clustering, endocytosis and signaling at the plasma membrane. Also, considered the fluidity and plasticity of lipid rafts, some proteins are localized stably and some other are transiently recruited to these specialized membrane areas. Among the stable proteins, the cellular prion protein (PrPC) localizes stably in lipid rafts microdomains and it can act as a cell surface receptor, co‐receptor or ligand, able to recruit downstream signal transduction pathways by the interaction with promiscuous partners. Among the transient proteins, it’s interesting to highlight the presence of the low‐density lipoprotein receptor‐related protein 1 (LRP1), a receptor partner of PrPC which was found localized transiently in lipid rafts, suggesting a different function of this receptor that through lipid raft becomes able to activate a signal transduction pathway triggered by specific ligands, including tissue Plasminogen Activator (tPA). Since it has been reported that PrPC participates in the tPA‐mediated plasminogen activation, in this study, we describe the role of lipid rafts in the recruitment and activation of downstream signal transduction pathways mediated by the interaction among tPA, PrPC and LRP1 in human neuroblastoma SK‐N‐BE2 cell line. Co‐immunoprecipitation analysis reveals a consistent association between PrPC and GM1, as well as between LRP1 and GM1, indicating the existence of a glycosphingolipid‐enriched multimolecular complex. In our cell model, knocking‐down PrPC by siRNA impairs ERK phosphorylation induced by tPA. Moreover, the alteration of the lipidic milieu of lipid rafts, perturbing the physical/functional interaction between PrPC and LRP1, inhibits this response. We show that LRP1 and PrPC, following tPA stimulation, may function as a system associated with lipid rafts, involved in receptor‐mediated neuritogenic pathway. We suggest this as a multimolecular signaling complex, which activity depends strictly on the integrity of lipid raft and is involved in the neuritogenic signaling.
Chronic Nicotine Inhalation Promotes Differential Remodeling of the Right and Left Ventricles in Mice
Authors: Fried Nicholas D. , Morris Tamara M. , Woods David C. , Oakes Joshua M. , Xu Jiaxi , Ninh Van K. , Lazartigues Eric , Yue Xinping , Gardner Jason D.
Published: April 2020

Introduction

Cigarette smoking continues to decline in the United States, but a rise in e‐cigarette use poses a threat to human health. E‐cigarettes, oft marketed as a healthier alternative to traditional forms of tobacco consumption, still contain nicotine. Cigarette smoking is a major risk factor in a vast array of pathological conditions including cancer and cardiovascular disease. Despite knowledge regarding the risks of cigarettes, the effects of inhaled nicotine have been poorly characterized. In this study, we sought to investigate the effects of inhaled nicotine on cardiac function and remodeling.

Methods

Male C57BL6/J mice were exposed to air (control) or nicotine vapor (daily, 12 hours on/12 hours off) for 8 weeks. Nicotine exposure was assessed by weekly measurement of serum cotinine levels, which showed an average of 599±54 ng/ml in nicotine‐exposed mice. A subset of mice were implanted with an Angiotensin‐II (AngII) osmotic minipump (450 ng/kg/min) for 4 weeks. Cardiac structure and function were assessed using echocardiography and cardiac catheterization, followed by tissue collection for analysis.

Results

Nicotine exposure produced a significant increase in right ventricular systolic pressure (RVSP; 39.6±4.2 mmHg, n=7) compared to air‐exposed controls (22.3±1.7 mmHg, n=8, p<0.01). Nicotine‐associated RVSP elevation was similar to AngII infusion (38.0±2.0 mmHg, n=7). RVSP changes were associated with RV hypertrophy (free wall thickness of 0.50±0.02 mm in nicotine exposure versus 0.42±0.03 mm in air‐exposed control, n=8–9, p<0.05) and increased angiotensin converting enzyme expression (3.87‐fold increase in nicotine exposure versus air‐exposed control, n=5, p<0.05).

Nicotine exposure alone produced no significant changes in left ventricular (LV) structure or angiotensin converting enzyme expression. Interestingly, co‐administeration of nicotine and AngII resulted in blunting of AngII‐mediated LV hypertrophy (posterior wall thickness; 0.83±0.03 mm versus 0.93±0.02 mm for AngII alone, n=19–23, p<0.01). Furthermore, we have found preliminary evidence of blunted LV hypertrophic signaling in nicotine‐exposed, AngII‐infused mice which exhibited reduced phosphorylated mTOR/mTOR compared to AngII alone (n=5, p=0.076).

Discussion

Taken together, these findings led us to conclude that chronic nicotine inhalation promotes differential remodeling of the right and left heart. Nicotine inhalation alone promotes hypertrophic remodeling of the RV, but produces no significant changes in the LV. Nicotine inhalation does, however, abrogate AngII‐induced hypertrophic LV remodeling. Ongoing experiments within our laboratory are exploring the mechanisms underlying this differential remodeling and anti‐hypertrophic effect.

Support or Funding Information

National Institutes of Health R01HL135635 (JG/EL/XY).
Student Perceptions and Learning Outcomes of a Dissection Handoff Procedure in the Gross Anatomy Laboratory
Authors: Walker Paul , Kupser Elizabeth , Donohue Laura , Tran Hanna , Qadeer Afreen , Swantek Alexander , Levine Diane
Published: April 2020

Background

Dissection of the human body takes considerable time and effort, but also provides opportunities for the introduction of clinical skills. One skill is the safe transfer (handoff) of a patient between healthcare teams, a process dependent on the accurate exchange of information. In order to provide medical students with opportunities to practice skills in teamwork and communication while also reducing time spent in the dissection process, a handoff procedure was piloted for use in the gross anatomy laboratory. This study reports initial findings on student perceptions of time usage, wellness, teamwork & communication skills, and relevance to patient handoff, as well as impact on learning and performance through analysis of assessment data.

Methods

First‐year medical students (n=296) at Wayne State University were briefed on how to complete handoffs and their fundamental role in care of future patients. Each anatomy group was divided into two groups, which alternated between roles as the “dissecting‐team” and “receiving‐team.” A handoff tool was developed and included written and verbal components. The written component included a standardized checklist, designed as a lab chart to ensure dissection as well as mimic a handoff document. During the verbal component, the dissecting‐team demonstrated structures to the receiving‐team and shared anticipated problems. The handoff trial took place during 10‐dissection labs covering the head and neck region. Students were asked to complete a presurvey prior to starting and a postsurvey after completing the handoff curriculum. Responses to the pre‐ and post‐ surveys were 59% and 61% of the class, respectively.

Results

On the presurvey, 71.6% of students agreed/strongly agreed that dissection was too time consuming compared to 64.8% on the postsurvey. 82.9% agreed/strongly agreed in the postsurvey that handoffs provided students with more time to study. On the practical exam students performed better on questions covering content when they were on the dissecting‐team 69.4% correct compared to receiver‐team 65.1% (P<0.0001). 61.3% said that handoffs positively affected their overall wellness in the postsurvey (up from 51.1% in the presurvey). 42.0% felt that the handoff process facilitated development of teamwork within their group while 58.0% felt neutral (28.2%) or disagreed (29.8%). 41.4% agreed participating in the handoff process helped them develop handoff skills necessary for patient handoffs while 58.6% were neutral (29.8%) or disagreed (28.7%).

Conclusion

Students scored significantly lower on exam questions regarding structures they did not dissect, but perceived they had more time to study and felt a positive effect on wellness. Improvements in the handoff procedure are needed to more directly address teamwork and communication skills pertinent to success with future patient handoffs.
The effect of switching the mediator of coronary endothelial dilation on coronary blood flow in metabolic syndrome
Authors: Wang Zhiyuan , Juguilon Cody , Gadd James , Enrick Molly , Jamaiyar Anurag , Wang Tao , Ohanyan Vahagn , Chilian William M. , Yin Liya
Published: April 2020

Diabetes mellitus is a leading risk factor for cardiovascular disease. One consequence of diabetes is microvascular dysfunction, which is speculated as an initial step in diabetic cardiomyopathy. However, the mechanisms of impaired coronary microvascular function in diabetes remain incompletely understood. NO is the major endothelial vasodilatory metabolite in the coronary circulation, but endothelium‐dependent dilation (E‐DD) in patients with coronary artery diseases switches from NO to H2O2. In a murine model of diabetes, we found a similar switch. Specifically in isolated coronary arterioles from wild type (WT) mice, E‐DD to acetylcholine (Ach) was reduced by L‐NAME, but this NOS antagonist did not affect Ach dilation in diabetic mice. However, in diabetic mice Peg‐catalase inhibited Ach ED‐D coronary dilation, but this scavenger of H2O2 did not affect dilation in WT mice. These results suggest that under normal conditions, endothelium‐dependent dilation is mediated by NO, but in diabetes, the mediator is H2O2. These results were observed in vitro and whether there is a functional consequence of this switch, in terms of flow regulation in vivo, is unknown. To understand this, WT, db/db mice and diet‐induced diabetic mice were anesthetized and the tail vein was catheterized for drug administration. Myocardial blood flow (MBF) was measured by contrast echocardiography and hemodynamics (blood pressure, heart rate) were measured via a pressure transducer. Our data show: 1) In db/db mice, MBF was significantly lower than MBF in WT mice during metabolic hyperemia produced by i.v. norepinephrine. MBF in diet‐induced diabetic mice was slightly lower compared to wild type. 2) L‐NAME attenuated the norepinephrine‐induced hyperemia in WT mice, but not in db/db mice. 3), Ebselen (a H2O2 scavenger) reduced the MBF in diabetic mice. These results suggest that NO to H2O2 switch in coronary endothelial dilation ex vivo also occurs in vivo and this switch can compromise blood flow regulation. Further study of the underlying mechanism may lead to the treatment to of diabetic cardiomyopathy—a condition with not accepted standard of care.
Metabolic reprogramming mediates macrophage polarization following myocardial infarction
Authors: Mouton Alan J. , Flynn Elizabeth R. , Hall Michael E. , Hall John E.
Published: April 2020

Macrophages play critical roles in mediating inflammation and cardiac remodeling after myocardial infarction (MI). Metabolic transitioning between glycolysis and oxidative phosphorylation (OXPHOS) is associated with macrophage polarization to pro‐inflammatory (M1) and anti‐inflammatory (M2) phenotypes. M1 macrophages rely on glycolysis and M2 macrophages rely on OXPHOS. However, the role of metabolism in macrophage polarization after MI is unknown. Thus, we hypothesized that inhibiting glycolysis after MI would promote macrophage polarization to an anti‐inflammatory M2 phenotype and improve post‐MI outcomes. MI was induced in adult male C57BL/6J mice by permanent left anterior coronary artery ligation for 1, 3, and 7 days. To directly assess macrophage glycolysis and OXPHOS after MI, macrophages (CD11b+Ly6−) were isolated from the infarct region (n=3 for D1 and D3) or healthy control hearts (day 0 or D0; n=3) by immunomagnetic separation or flushed from the peritoneal cavity and subjected to Seahorse analysis to determine the extracellular acidification rate (ECAR) and the oxygen consumption rate (OCR). To assess the role of macrophage metabolism, a separate group of mice was administered dimethyl fumarate (DMF, 15mg/kg I.P.) or vehicle solution as a control, for the first 3 days after MI to inhibit macrophage glycolysis during the acute inflammatory response, and studied at day 7. DMF is a clinically approved anti‐inflammatory drug with immunometabolic properties. Left ventricular (LV) function was assessed by echocardiography. Infarct macrophage phenotypes were determined by flow cytometry. By Seahorse analysis, DMF inhibited glycolysis in vitro in peritoneal macrophages. The basal glycolytic ECAR was increased in macrophages at D1 (0.3±0.1 mPh/min D0 versus 4.2±1.0 mPh/min D1) and further increased at D3 (8.9±1.2 mPh/min D3). Maximal glycolytic capacity was similarly increased in D1 and D3 versus D0 (6.0±1.3 mPh/min D1 and 10.8±1.7 mPh/min D3 versus 0.4±0.5 mPh/min D0). No differences were observed in basal, maximal or spare capacity OCR, indicating that increased glycolysis alone mediates macrophage polarization after MI. Treatment with DMF improved the post‐MI survival rate after 7 days by 11%. Of the surviving mice (n=3 each group), no differences in the LV, RV, lung, or spleen mass were observed. By echocardiography, DMF did not affect LV diastolic or systolic volumes, ejection fraction, or anterior wall thinning, but prevented MI‐induced LV posterior wall thinning (0.73±0.14 mm DMF versus 0.42±0.09 mm vehicle). By flow cytometry, DMF increased the number of M2 macrophages (CD45+CD11b+Ly6G−CD206high) in the infarcted region (62±13% DMF versus 40±2% vehicle). In conclusion, macrophage metabolic reprogramming underlies polarization after MI, and targeting macrophage metabolism may improve post‐MI LV remodeling and survival.

Support or Funding Information

NHLBI‐PO1HL51971, NIGMS P20GM104357 and U54GM115428; AHA 18POST34000039.
Y‐Chromosome Gene, Uty, Protects Against Pulmonary Hypertension by Reducing Lung Pro‐Inflammatory Cytokines
Authors: Cunningham Christine Marie , Umar Soban , Doshi Mitali , Li Min , Ruffenach Gregoire , Hrncir Haley , Arnold Arthur P. , Eghbali Mansoureh
Published: April 2020

RATIONALE

Idiopathic pulmonary arterial hypertension (PAH) is a terminal vascular lung disease up to 4x more common in females. We published that the Y‐Chromosome (Chrm) is protective against hypoxia (Hx)‐induced pulmonary hypertension (PH) in mice and identified four Y‐Chrm genes expressed in the lung. Here, we identify Uty as the protective Y‐Chrm gene and investigate its mechanism of protection against PH to illuminate novel therapeutic targets.

METHODS AND RESULTS

To test the effect of Y‐Chrm candidate genes on PH development, each of the four candidate YChrm genes were independently knocked‐down in the lungs of male mice exposed to Hxinduced PH via sequential intratracheal instillation of siRNA. Knockdown of Y‐Chrm gene Uty, but none of the other genes, resulted in more severe PH measured by increased right ventricular systolic pressure (RVSP) and decreased pulmonary arterial acceleration time (PAAT) when compared to experimental controls (n=4/group; RVSP: Uty‐KD= 48.93 mmHg, Control= 37.33 mmHg, p=0.04; PAAT: Uty‐KD= 11.88 ms, Control= 14.43 ms, p= 0.01). Pathway enrichment analysis of RNAseq data (Uty‐Knockdown vs Control) revealed an induction of proinflammatory cytokines including Cxcl9 (Log2FC: 1.3, p‐adjusted= 0.05) and Cxcl10 (Log2FC: 0.9, p‐adjusted=0.002). We found Cxcl9 and Cxcl10 were also significantly up‐regulated in human PAH lungs vs healthy (RT‐qPCR) and female PAH lungs vs male (GSE15197). Fluorescent in‐situ hybridization revealed Uty expression co‐localized with CD68+ macrophages, Cxcl9 and Cxcl10 in the lung. Upon stimulation, macrophages derived from bone marrow of male Uty‐knockout mice displayed increased expression of Cxcl9 and Cxcl10 compared to wildtype mice. Human pulmonary artery endothelial cells treated with Cxcl9 and Cxcl10 in‐vitro exhibited significantly increased cell death compared to those treated with vehicle.

CONCLUSION

Y‐Chrm gene, Uty, is protective against PH development and may explain Y‐Chrm protection in PH. Since Uty inhibition (both in‐vitro and in‐vivo) results in an increase in pro‐inflammatory cytokines, we hypothesize that a reduction or absence of Uty in the lungs of PAH patients or females results in an increase in lung pro‐inflammatory cytokines which contributes to vascular endothelial dysfunction and more severe PH.

Support or Funding Information

American Heart Association grant 17PRE33420159 (C.M.C.), Iris Cantor‐UCLA Women’s Health Center Executive Advisory Board NCATS UCLA CTSI Grant Number UL1TR001881 (C.M.C.), and NIH grants R01HL129051 (M.E.), R01HL131182 (M.E. and A.P.A.).
Noise‐induced vascular dysfunction, oxidative stress and inflammationare improved by pharmacological heme oxygenase‐1 induction
Authors: Jimenez Maria Teresa Bayo , Steven Sebastian , Kröller-Schön Swenja , Frenis Katie , Kalinovic Sanela , Stamm Paul , Oelze Matthias , Daiber Andreas , Münzel Thomas
Published: April 2020

Endothelial dysfunction, vascular oxidative stress and inflammation are consequences of traditional cardiovascular risk factors and triggers of cardiovascular disease. However, emerging environmental stressors such as traffic noise exposure may facilitate the development of cardiovascular and metabolic diseases.

C57BL/6J mice were exposed to aircraft noise (maximum sound level of 85 dB(A), average sound pressure level of 72 dB(A)) applied for 1, 2 and 4 days caused an increase in systolic blood pressure, stress hormones and induced endothelial dysfunction, oxidative stress and inflammation (Eur Heart J 2017). We also observed reduced vascular NO levels due to eNOS uncoupling and increased levels of nitrotyrosine, interleukin‐6, NADPH oxidase isoform Nox2 and endothelin‐1 in the mice exposed to aircraft noise. More recently, we have shown that aircraft noise induces also cerebral oxidative stress and a neuroinflammatory phenotype that is up‐stream of the observed adverse cardiovascular effects, all of which was normalized by genetic deletion of NADPH oxidase isoform Nox2 (Eur Heart J 2018).

The role of heme oxygenase‐1 (HO‐1) as an antioxidant response is currently being investigated. C57BL/6J mice were treated with the HO‐1 activator hemin (25 mg/kg i.p.). Our preliminary data show a protective effect of hemin infusion on aircraft noise exposure (4 days) induced increase of systolic blood pressure and vascular dysfunction. There was also a trend of normalization of noise‐triggered oxidative stress ny hemin infusion. Within the ongoing studies, we will address the impact of HO‐1 induction in noise‐exposed mice on expression of genes and proteins involved in pathways of oxidative stress and systemic inflammation. In a later stage of the study, we will also test whether genetic deficiency of HO‐1 (HO‐1+/− mice) aggravates and the Nrf2 activator dimethyl fumarate (DMF) ameliorates noise‐triggered cardiovascular complications. The present study aims at identifying new targets for mitigation strategies against adverse health effects of environmental noise exposure of the general population. Since HO‐1 and Nrf2 induction can be achieved by natural dietary constituents, these pathways represent promising targets for preventive measures.

Support or Funding Information

Our experimental studies on noise effects in mice were supported by vascular biology research grants from the Else‐Kröner‐Fresenius Foundation for “Noise and arterial hypertension” (2017_A106) and the Boehringer Ingelheim Foundation for the collaborative research group „Novel and neglected cardiovascular risk factors: molecular mechanisms and therapeutic implications”.
Identification and Characterization of Small‐Molecule Ras Modulators and their Impact in Cancer Drug Discovery
Authors: DePaolo Patrick Anthony , Windsor William , Sabio Michael , Tolias Peter
Published: April 2020

Ras is a small GTPase enzyme that binds guanine diphosphate (GDP), a nucleotide substrate, to its guanine‐nucleotide binding pocket. Ras activation occurs by the coordination of SOS, a guanine nucleotide exchange factor, which catalyzes the substitution of GDP for guanine triphosphate (GTP), rendering the Ras protein in an active state. Oncogenic Ras mutants are constitutively active, propagating proliferative cell signaling that leads to aberrant cell growth and metastatic tumors that are present in 30% of all human cancers. Discovery of a potent, small molecule Ras inhibitor has been challenging. We have characterized a novel class of Ras modulators that exhibit both Ras activation. These small molecules were discovered using Ras‐SOS molecular modeling and computational docking studies focused on identifying potential compound binding to the Ras‐SOS complex interface. Several in‐vitro biochemical assays were performed to elucidate the structural significance, binding kinetics, and nucleotide exchange effects of these small molecule binders. A fluorescence nucleotide exchange assay was optimized to discover compounds that had an atypical nucleotide exchange rate (off‐state to on‐state) in a kinetic assay. Compounds discovered in the assay were then analyzed by Surface Plasmon Resonance (SPR) to further elucidate details on the binding kinetics between Ras and compound as well as between Ras and SOS in the presence of the compound. Of the examined compounds, several exhibited activation of the Ras‐SOS catalytic reaction. An ongoing structure activity relationship (SAR) study has identified essential components that facilitate binding to the Ras:SOS interface. This presumably allosteric interaction may have uncovered an unprobed regulatory site that can be manipulated to create Ras inhibitors. This discovery of activator compounds provides a promising new direction for the development of potent Ras modulators.

Support or Funding Information

The Center for Healthcare Innovation (CHI), Stevens Institute of Technology
ADAM17 Cleaves the Insulin Receptor Ectodomain on Endothelial Cells and Induces Vascular Insulin Resistance
Authors: Ghiarone Thaysa , Castorena-Gonzalez Jorge , Foote Christopher A. , Ramirez-Perez Francisco , Wheeler Andrew A. , Rawlings Arthur L. , Staveley-O’Carrol Kevin F. , Padilla Jaume , Martinez-Lemus Luis A.
Published: April 2020

Despite efforts to reduce the incidence of type 2 diabetes (T2D) and its cardiovascular consequences, T2D‐associated cardiovascular mortality continues to rise in the US and worldwide. The presence of a pro‐inflammatory state and microvascular insulin resistance are hallmarks of T2D that contribute to cardiovascular disease. The former is associated with increased activity of ADAM17, an enzyme that cleaves the ectodomain of multiple transmembrane proteins, while the latter is characterized by decreased insulin‐induced vasodilatory responses. However, the specific mechanisms, including the potential role(s) of ADAM17, underlying vascular insulin resistance in T2D, remain unknown. We hypothesize that in T2D, increased expression and activation of ADAM17 sheds the insulin receptor ectodomain (IRα) from endothelial cells and thus impairs insulin‐induced vasodilation. We tested this hypothesis using isolated small visceral arteries from T2D and non‐T2D subjects undergoing bariatric surgery and cultured human endothelial cells. Results indicate that arteries from subjects with T2D exhibit increased ADAM17 expression, reduced presence of TIMP3 (the endogenous inhibitor of ADAM17), decreased extracellular IRα, and impaired insulin‐induced vasodilation in comparison with arteries from non‐T2D subjects (P<0.05). In vitro, ADAM17 cleaved insulin receptor recombinant proteins at a specific extracellular site of the IRβ subunit (p<0.05). Exposure of endothelial cells to the PKC activator, PMA, increased the shedding activity of ADAM17 (P<0.05) and decreased the presence of IRα on cell surfaces occupied by ADAM17, as observed using super‐resolution microscopy. Moreover, pharmacological inhibition of ADAM17 with TAPI‐0 rescued PMA‐induced impairments in insulin signaling in endothelial cells and insulin‐stimulated vasodilation in human small visceral arteries (P<0.05). Collectively, these findings suggest that ADAM17‐mediated shedding of IR ectodomains from the endothelial surface impairs insulin‐mediated vasodilation. Therefore, inhibition of ADAM17 sheddase activity should be considered a potential new therapeutic strategy to restore vascular insulin sensitivity in T2D.

Support or Funding Information

Research support: National Institutes of Health grants: R01 HL137769 (JP), R01 HL088105 (LM‐L).
Allelic insufficiency of Znt8 had improved glucose tolerance in male mice after high fat intake
Authors: Cai Yimeng , Kirschke Catherine , Huang Liping
Published: April 2020

Zinc transporter 8 (ZNT8) is mainly expressed in the pancreatic β‐cell. ZNT8 transports zinc from the cytosol into the insulin‐containing secretory vesicle for insulin crystallization and secretion. Reduced ZNT8 expression affects glucose‐stimulated insulin secretion. Genome Wide‐Association Studies revealed that people with one null allele of ZNT8 are 65% less likely to develop type 2 diabetes (T2D) than those with two normal alleles. The molecular mechanism underling this protective function of ZNT8 allelic insufficiency is not clear. Our specific aim was to uncover this mechanism using Znt8+/− mice. We hypothesized that Znt8 allelic insufficiency caused a decrease in glucose‐stimulated insulin secretion which triggered a compensatory action that ensured normal blood glucose levels after a meal. In the current study, we fed Znt8+/− and control mice a high‐fat diet to induce insulin resistance. The results from this study suggest a gender‐dependent role of Znt8 allelic insufficiency in the protection of mice from T2D. We found that male mice were benefited from Znt8 heterozygosity for controlling glucose levels whereas Znt8 heterozygosity helped female mice for handling dietary lipids. Importantly, we found that glucagon may play a key role in controlling glucose levels in Znt8+/− mice. In conclusion, our data support the notion that allelic Znt8 insufficiency can provide a protective effect against diet‐induced glucose intolerance, possibly through regulation of glucagon secretion.

Support or Funding Information

USDA/ARS 2032‐51000‐005‐00D.
Low Rates of Cascade Genetic Testing Among Families With Hereditary Gynecologic Cancer: An Opportunity to Improve Cancer Prevention
Authors: Griffin Natalie E. , Buchanan Tommy R. , Smith Stephanie H. , Leon Andrea A. , Meyer Melissa F. , Liu Jingxia , Tabak Rachel G. , Fuh Katherine C. , Thaker Premal H. , Powell Matthew A. , Mutch David G. , Massad L. Stewart , Colditz Graham A. , Hagemann Andrea R.
Published: April 2020

(Abstracted from Gynecol Oncol 2020;156:140–146)

The 2 most common germline mutations causing cancer in the United States are BRCA1/2 mutations associated with hereditary breast and ovarian cancer (HBOC) and mismatch repair (MMR) gene mutations associated with Lynch syndrome (LS). A first-degree relative of a patient with one of these mutations incurs a 50% chance of inheriting the same mutation, and early detection can inform treatment and preventive procedures.
Timing of Office-Based Pessary Care: A Randomized Controlled Trial
Authors: Propst Katie , Mellen Colleen , O'Sullivan David M. , Tulikangas Paul K.
Published: April 2020

(Abstracted from Obstet Gynecol 2020;135:100–105)

Vaginal pessaries are recommended often as first-line treatment of pelvic organ prolapse and stress urinary incontinence, especially for women who do not desire surgery or who are poor surgical candidates. Several studies have shown that pessaries improve symptoms of prolapse, bowel symptoms, body image perception, and overall quality of life.
A retrospective study of idiopathic clubfoot managed by Ponseti method using Pirani and Dimeglio scoring, in Indian population: a minimum 3-year follow-up
Authors: Narasimhan Ramani , Panda Anil Kumar , John Rakesh
Published: April 2020

Congenital talipo-equino-varus (CTEV) is one of the most common congenital deformities affecting children in India with an incidence of 1.19/1000 live births. Ponseti treatment regimen has been established as the gold standard of care for idiopathic clubfoot. We present quantitative and qualitative analysis of the results of Ponseti management in early presenting idiopathic clubfoot cases, with a minimum follow-up of three years after correction. We retrospectively analysed the data of 122 children (comprising a total of 191 feet) who were treated for clubfoot by the standard Ponseti method with a minimum 3-year follow-up post-correction at our clinic. All cases were treated under the supervision of a single senior Paediatric Orthopaedic Surgeon. The mean age at onset of treatment was 2.3 months. Mean follow-up period was 4.2 years. The mean number of casts applied was 6.7. The mean duration of treatment until the application of splint was 9.5 weeks. The mean Pirani score at the commencement of treatment was 4.5. At the completion of treatment (around 3.6 years of age), the Dimeglio score was ‘Benign’ (Good) in 106 cases, ‘Moderate’ (Fair) in 11 cases and ‘Severe/Very Severe’ (Poor) in 5 cases. The P-value was calculated to be 0.8 for the sex-wise comparison of the treatment outcome. Ponseti method of nonoperative treatment for idiopathic clubfeet remains a gold standard for all cases treated during infancy. Identifying atypical clubfeet is important as their prognosis ought to be guarded. Despite facing problems at various stages of management, adhering to the basic treatment principles laid down by Ponseti helps in achieving good outcomes in majority. Level of Evidence: IV.
Occipital Plate Fixation in the Pediatric Population
Authors: Cohen Lara L. , Yang Brian W. , Glotzbecker Michael P. , Emans John B. , Karlin Lawrence I. , Snyder Brian D. , Hresko Michael T. , Hedequist Daniel J.
Published: April 2020

Background:

Occipital plate fixation has been shown to improve outcomes in cervical spine fusion. There is a paucity of literature describing occipital plate fixation, especially in the pediatric population. The authors reviewed a case series of 34 patients at a pediatric hospital who underwent cervical spine fusion with occipital plate fixation between 2003 and 2016. This study describes how occipital plates aid the cervical spine union in a case series of diverse, complex pediatric patients.

Methods:

Our orthopaedic database at our institution was queried for patients undergoing an instrumented cervical spine procedure between 2003 and 2016. Medical records were used to collect diagnoses, fusion levels, surgical technique, and length of hospitalization, neurophysiological monitoring, complications, and revision procedures.

Results:

Thirty-four patients met the inclusion criteria. The mean age was 10.9 years (range, 3-21 y). Indications for surgery included cervical instability, basilar invagination, and os odontoideum. These indications were often secondary to a variety of diagnoses, including trisomy 21, Klippel-Feil syndrome, and rheumatoid arthritis. The mean length of hospitalization was 10 days (range, 2 to 80 d). There were no cases of intraoperative dural leak, venous sinus bleeding from occipital screw placement, or implant-related complications. Postoperative complications included 2 cases of nonunion. Eight patients (24%) had follow-up surgery, only 3 (9%) of which were instrumentation revisions. Both patients with nonunion had repeat occipitocervical fixation procedures and achieved union with revision.

Conclusions:

Occipital plate fixation was successful for pediatric cervical spine fusion in this diverse cohort. The only procedure-related complication demonstrated was delayed union or nonunion and implant loosening (4/34, 12%) and there were no plate-related complications. This novel case series shows that occipital plate fixation is safe and effective for pediatric patients with complex diagnoses.

Level of Evidence:

Level IV—case series.
Prolonged Postoperative Intubation After Spinal Fusion in Cerebral Palsy: Are There Modifiable Risk Factors and Associated Consequences?
Authors: LaValva Scott M. , Baldwin Keith , Swarup Ishaan , Flynn John M. , Pahys Joshua M. , Yaszay Burt , Abel Mark F. , Bachmann Keith , Shah Suken A. , Sponseller Paul D. , Cahill Patrick J.
Published: April 2020

Background:

Instrumented spinal fusion is performed to correct severe spinal deformity that commonly complicates cerebral palsy (CP). Prolonged intubation (PI) is a common perioperative complication, though little is known about the risk factors and consequences of this phenomenon.

Questions/Purposes:

The purpose of this study was to determine (1) the preoperative and intraoperative risk factors associated with PI after spine surgery for CP; (2) the perioperative and postoperative complications associated with PI; and (3) any long-term impacts of PI with respect to health-related quality of life.

Patients and Methods:

A retrospective case-control analysis of prospectively collected, multicenter data was performed on patients with Gross Motor Function Classification System (GMFCS) 4 or 5 CP who underwent instrumented spinal fusion. Patients extubated on postoperative day (POD) 0 were in the early extubation (EE) cohort and those extubated on POD 3 or later were in the PI cohort. Comparisons were made between PI and EE groups with respect to several preoperative and intraoperative variables to identify risk factors for PI. Multivariate logistic regression was performed to identify independent predictors of this outcome. The postoperative hospital course, rate of complications, and health-related quality of life at 2 years were also compared.

Results:

This study included 217 patients (52% male individuals; mean age, 14.0±2.8 y) who underwent spinal fusion for CP. In this cohort, 52 patients (24%) had EE and 58 patients (27%) had PI. There were several independent predictors of PI including history of pneumonia [odds ratio (OR), 6.2; 95% confidence interval (CI), 1.6-24.3; P=0.01], estimated blood loss of >3000 mL (OR, 16.5; 95% CI, 2.0-134; P=0.01), weight of <37 kg (OR, 6.4; 95% CI, 1.5-27.1), and Child Health Index of Life with Disabilities (CPCHILD) Communication and Social Interaction score of <15 (OR, 10.8; 95% CI, 1.1-107.3; P=0.04). In addition, PI was associated with a higher rate of perioperative and postoperative respiratory (P<0.001), cardiovascular (P=0.014), gastrointestinal (P<0.001), and surgical site (0.027) complications, in addition to prolonged hospitalization (P<0.001) and intensive care unit stay (P<0.001).

Conclusions:

Surgeons should seek to optimize nutritional status and pulmonary function, and minimize blood loss in patients with CP to decrease the risk of PI after spinal fusion. Efforts should be made to extubate patients on POD 0 to decrease the risk of complications associated with PI.
Risk of Mortality in Immunocompromised Children With Severe Sepsis and Septic Shock
Authors: Lindell Robert B. , Nishisaki Akira , Weiss Scott L. , Traynor Danielle M. , Fitzgerald Julie C.
Published: April 2020

Objectives:

To assess the prevalence of immunocompromised diagnoses among children with severe sepsis and septic shock, and to determine the association between immunocompromised diagnoses and clinical outcomes after adjustment for demographics and illness severity.

Design:

Retrospective multicenter cohort study.

Setting:

Eighty-three centers in the Virtual Pediatric Systems database.

Patients:

Children with severe sepsis or septic shock admitted to a participating PICU between January 1, 2012, and December 31, 2016.

Interventions:

None.

Measurements and Main Results:

Across 83 centers, we identified 10,768 PICU admissions with an International Classification of Diseases, 9th Revision, Clinical Modification code for severe sepsis or septic shock; 3,021 of these patients (28%) had an immunocompromised diagnosis. To evaluate variation across centers and determine factors associated with PICU mortality, we used mixed-effect logistic regression models. Among patients without hematopoietic cell transplant, congenital immunodeficiency (adjusted odds ratio, 1.90; 95% CI, 1.24–2.92), multiple prior malignancies (adjusted odds ratio, 1.86; 95% CI, 1.15–2.99), and hemophagocytic lymphohistiocytosis (adjusted odds ratio, 3.09; 95% CI, 1.91–4.98) were associated with an increased odds of PICU mortality. Among patients with prior hematopoietic cell transplant, liquid malignancy (adjusted odds ratio, 3.15; 95% CI, 2.09–4.74), congenital immunodeficiency (adjusted odds ratio, 6.94; 95% CI, 3.84–12.53), multiple prior malignancies (adjusted odds ratio, 3.54; 95% CI, 1.80–6.95), and hemophagocytic lymphohistiocytosis (adjusted odds ratio, 2.79; 95% CI, 1.36–5.71) were associated with an increased odds of PICU mortality. PICU mortality varied significantly by center, and a higher mean number of sepsis patients per month in a center was associated with lower PICU mortality (adjusted odds ratio, 0.94; 95% CI, 0.90–0.98). PICU resource utilization varied by immunocompromised diagnosis and history of hematopoietic cell transplant, and among survivors immunocompromised patients have shorter median PICU length of stay compared with patients without immunocompromised diagnoses (p < 0.001).

Conclusions:

Immunocompromised diagnoses are present in 28% of children with severe sepsis or septic shock. Multiple prior malignancies, hemophagocytic lymphohistiocytosis, congenital immunodeficiency, and hematopoietic cell transplant are independently associated with an increased odds of PICU mortality in children with severe sepsis or septic shock. Significant variation exists in PICU mortality among centers despite adjustment for immunocompromised diagnoses, known risk factors for sepsis-related mortality, and center-level sepsis volume.