bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Pigment Epithelium‐Derived Factor’s Anti‐Angiogenic Properties on Tumor Suppression
Authors: Wagoner Natalie , Welker Blake , Muralidharan Mahathi , Weltert Gioia
Published: April 2020

Pigment epithelium‐derived factor (PEDF) is a multimodal secreted glycoprotein of roughly 50kDa size and 418 amino acids in length and is found in the interphotoreceptor matrix (ICM) that holds a variety of biological functions. It is a member of the non‐inhibitory serpin family and was first identified as a neurotrophic factor in retinal pigment epithelial cells, however, it has also been identified in several tissues throughout the body including the heart, lung, brain, and pancreas. PEDF is highly conserved throughout evolution and is known to possess neurotrophic, neuroprotective, anti‐tumorigenic, anti‐metastatic properties, and anti‐angiogenic properties. Indeed, PEDF is known as one of the most potent naturally occurring anti‐angiogenic agent. Angiogenesis plays a critical role in the development of cancer because it stimulates the formation of new blood vessels which carry blood to the tumor thereby providing it unlimited access to critical nutrients and oxygen needed for sustained growth and metastatic spread. Hence, the ability of PEDF to block angiogenesis highlights its potential as a novel anti‐cancer agent. Apart from inhibiting angiogenesis, PEDF also inhibits cancer cell proliferation and induces programmed cell death (apoptosis) through activation of FasR/FasL death signaling pathway. The importance of PEDF in cancer is validated by the fact that its expression is significantly reduced in several types of cancers and that loss of PEDF expression is associated with aggressive disease and poor overall survival. Indeed, PEDF expression has been shown to be markedly reduced in breast tumors compared with normal breast tissue and loss of PEDF is associated with resistance to anti‐endocrine therapy due to activation of two critical breast cancer proteins; the estrogen receptor (ER) and the Rearranged during Transfection (RET) proteins. The unique biology of the PEDF protein is directly related to its structure. PEDF is asymmetrically charged, one side being highly acidic the other highly basic, giving it a polar structure that has two functional epitopes. The acidic region contains a 34‐mer peptide that interacts with the PEDF‐RA receptor identified in endothelial cells. When this interaction occurs, apoptosis is initiated, epithelial cell migration is blocked, and corneal angiogenesis is induced. On the other hand, the basic region consists of a 44‐mer peptide that interacts with the PEDF‐RN receptor which has been identified on Y‐79 cells, cerebellar and motor neurons, and in the neural retina. When this epitope is activated, PEDF assists in conducting neural differentiation.

Support or Funding Information

The Olathe North MSOE Center for BioMolecular Modeling SMART Team used 3‐D modeling and printing technology to examine structure‐function of PEDF
3D‐Printing Technologies and You: How to Choose a Printing Solution for Your Institution
Authors: Barger John Bradley , Edwards Danielle , Resuehr David
Published: April 2020

With the rapid expansion and increased availability of 3D printing technologies, many colleges and universities are adding 3D‐printing “Maker Spaces” to their campuses. However, the full potential of these technologies often goes unrealized. Whether due to lack of training, planning or knowledge, many departments, especially in medical education, are failing to leverage the enormous potential of 3D printing. This poster aims to fill this ‘potential gap’ by helping you to plan and utilize 3D‐printing in education, training, and clinical practice. We will focus on the hardware side of 3D‐printing, with a primer on different 3D‐printing technologies, including the pros and cons of each. Cost, resolution, and print speed are the usually the primary factors in deciding on a 3D‐printer, but we will also consider printing medium, and how print material dictates the way 3D‐models can be used. This poster will present a hypothetical ‘decision tree’ that will aid you in choosing a printing solution for your goals and institution.
Determining the role for Nuclear receptor SHP in liver and kidney metabolism
Authors: Shaw Ryan P.H.
Published: April 2020

Nuclear receptors are a unique family of ligand‐activated transcription factors that can modulate gene expression across various cellular functions. Nuclear receptor SHP (Small Heterodimer Partner), is atypical such that it lacks the DNA binding domain and its endogenous ligand is currently unknown. SHP is well known for regulating hepatic bile acid synthesis as a downstream target of nuclear receptor FXR. But previously published reports suggest that SHP may control heart function, germ cell differentiation, and cellular transport. Therefore, we set to investigate SHP function in both liver and extra‐hepatic tissues using mouse models. Since SHP can regulate nuclear receptor Constitutive Androstane Receptor (CAR) that is primarily responsible for drug metabolism, we examined a role for SHP in coordinating detoxification pathways. In the liver, absence of SHP resulted in robust increases in cyclins in response to CAR activation despite no liver growth. Detoxification is largely controlled by a trifecta of organs consisting of the liver, gut, and kidney, where SHP expression is noticeable. In fact, some of the detoxifying phase I, II and III genes also control bile acid homeostasis. We have found under cholestatic conditions liver expression of phase I metabolic pathway genes (CYP1A2 and CYP2E10) were significantly repressed whereas phase II metabolic genes (GSTM1 and GSTA2) are upregulated in the absence of SHP. We also found that the deletion of FXR and SHP altered organic solute transporters and GSTA1/2 mRNA levels in kidneys. This data suggests that murine SHP may regulate phase I and II metabolic processes distinctly in the liver and potentially contribute towards glutathione conjugation in the kidney.

Support or Funding Information

NIDDK(R01 DK113080 AE433)
Trait Anxiety and Blood Pressure Reactivity to Mental Stress
Authors: Bigalke Jeremy A. , Fonkoue Ida T. , Greenlund Ian M. , Carter Jason R.
Published: April 2020

Chronic stress is a prevalent issue among the general population, and has been associated with other comorbid pathologies. Despite its widespread impact, the effects of chronic stress on cardiovascular outcomes are not well understood. The purpose of this study was to assess the role trait anxiety might play in blood pressure reactivity at the onset of psychological stress, namely mental arithmetic. We hypothesized that increased trait anxiety levels would be correlated with an augmented blood pressure response at the onset of mental stress, indicating a higher cardiovascular reactivity to stress. Twenty‐four adults (10 men, 14 women; 22±1 years) were assessed during a three‐minute supine baseline followed by five minutes of psychological stress (mental arithmetic). Physiological variables measured included heart rate (HR; electrocardiogram) and blood pressure (sphygmomanometer and finger plethysmography). Trait anxiety was measured prior to the experiment (Spielberger Trait Anxiety Inventory). Average raw and standardized trait anxiety levels were 32±2 and 42±2, respectively. Due to low representation of severe anxiety, a tertile analysis was performed on both raw (n=8 per tertile) and standardized trait (T1: n=8, T2: n=7, T3: n=9) anxiety levels to assess blood pressure reactivity between the different severities represented in our sample population. Mental stress significantly (p<0.001) increased mean arterial pressure (MAP; Δ10±1 mmHg), systolic pressure (SAP; Δ10±2 mmHg), diastolic pressure (DAP; Δ9±1 mmHg), and heart rate (HR; Δ14±1 beats/min), but these increases were not significantly different between tertiles (p>0.05). However, during the first minute following the onset of mental stress, ANOVA analysis revealed a significant difference in the increase of MAP between tertiles (p=0.05). Following post hoc analysis, the first raw trait anxiety tertile exhibited a greater increase (p<0.05) in MAP (Δ8 ±2 mmHg) when compared to tertiles two (Δ2±2 mmHg) and three (Δ2±2 mmHg). Similarly, the first standard trait anxiety tertile showed a significantly greater increase (p<0.05) in MAP (Δ8±2 mmHg) when compared to both tertile two (Δ2±2 mmHg) and three (Δ2±2 mmHg). Contrary to our hypothesis, the results of this study indicate a decreased cardiovascular stress response and potential autonomic dysregulation in individuals with heightened stress levels. These results suggest the use of subjective anxiety questionnaires may be helpful during autonomic function testing to better account for the potential role of anxiety in cardiovascular reactivity.

Support or Funding Information

NIH R01 AA‐024892 and NIH R21 HL098676
Microbiota‐derived Purines Support Intestinal Proliferation and Mucus Barrier Integrity
Authors: Lee J. Scott , Wang Ruth , Goldberg Matthew , Kao Daniel , Colgan Sean
Published: April 2020

The gastrointestinal mucosa forms a dynamic physical and biochemical barrier to isolate the host immune system from potentially pathogenic microorganisms. A dysfunctional barrier allows bacterial contact with and translocation across the epithelium. Recent studies have appreciated that epithelial barrier formation and maintenance is energetically demanding, yet the colonic epithelium exists in a rather energetically‐depleted state of physiological hypoxia. Moreover, the intestinal mucosa is short lived, undergoing turnover every 3 – 5 days, incurring a substantial need for nucleotide genesis to preserve the epithelial cell population and provide ATP for energy balance. In the present work, we demonstrate that large quantities of purines are made and released by the gut microbiota and that such microbiota‐derived purines (MDP) are available to the intestinal mucosa. Through a series of experiments in which MDP production was depleted by antibiotic treatment, and purines reconstituted by supplementation and colonization with purine‐producing bacteria, the contribution of MDP to colonic proliferation and energetics during DSS‐induced colitis was delineated. Through HPLC‐based metabolite analyses, exogenously supplied purines showed incorporation into the murine colonic purine metabolite pool, were utilized for nucleotide genesis, and promoted energy balance. Immunofluorescent and metabolite analyses revealed that DSS‐insulted colon tissue lacking MDP substrates were proliferatively stunted, with notable energetic and endoplasmic reticulum (ER) stress, to the detriment of mucus barrier integrity. Upon purine reconstitution, the energetic state of the tissue was improved and ER stress alleviated, with concomitant reclamation of proliferative capacity and mucus barrier sterility. Together, this work establishes MDP as a critical substrate for colonic tissue metabolism and facilitates mucosal homeostasis and inflammatory resolution.

Support or Funding Information

This work was supported by NIH grants F32DK122741, DK1047893, DK50189, DK095491, DK103712 and by the Veterans Administration Merit Award BX002182.
Control of Instant Membrane Resealing by Lysosomal Acid Ceramidase in Endothelial Cells
Authors: Huang Dandan , Li Guangbi , Yuan Xinxu , Zou Yao , Li Pin-Lan
Published: April 2020

Previous studies have shown that lysosome exocytosis and ceramide platform formation in the outer leaflet of the lipid bilayer are essential for plasma membrane repair. As a lysosomal enzyme catalyzing ceramide hydrolysis, the role of acid ceramidase (AC) in the control of cell membrane repair remains unknown. In the present study, we tested a hypothesis that lysosomal AC‐mediating signaling plays a crucial role in instant membrane resealing of endothelial cells (ECs), which help maintain the integrity of EC membrane and related functional activity. By Western blot analysis, it was found that carmofur, an AC inhibitor, decreased the AC expression in murine ECs. On the contrary, Genistein, an AC activator, elevated the level of AC in these cells. Using wavelength‐switching fluorescent microscopy with propidium iodide (PI), a fluorescent membrane‐impermeant dye as membrane resealing marker and fura‐2 as intracellular Ca2+ indicator, we monitored instant membrane resealing following saponin‐induced membrane disruption simultaneously with Ca2+ influx recording in murine ECs. The speed of PI fluorescence increase (df/dt) within ECs and time to a peak of PI fluorescence elevation were used to reflect the instant membrane resealing. Under Ca2+‐free condition, we found that membrane resealing in ECs was enhanced by carmofur as shown by df/dt reduction, but inhibited by genistein (increase in df/dt). In Hanks’ buffer containing Ca2+, however, carmofur and genistein failed to alter membrane resealing of murine ECs when Ca2+ influx was increased. In isolated coronary ECs from WT/WT and Asah1fl/fl/Endocre mice, we demonstrated that AC gene knockout specifically in ECs remarkably enhanced membrane resealing following saponin‐induced membrane interruption, which also mainly occurred under Ca2+‐free condition. These results suggest that lysosomal AC expression and activity are critical for the regulation of instant membrane resealing in ECs after acute injury, which represents a Ca2+‐independent membrane repairing mechanism.

Support or Funding Information

This study was supported by NIH grants DK54927 and DK102539.
The Vascular Supply to Human Brown Adipose Tissue
Authors: Coolbaugh Crystal L. , George Mark K. , Hooijmans Melissa T. , Damon Bruce M.
Published: April 2020

Brown adipose tissue (BAT) engages in non‐shivering thermogenesis in response to cold exposure. Several aspects of its function require significant arterial and venous supplies. For example, the arterial system delivers endocrine signaling molecules and metabolic substrates including glucose and non‐esterified fatty acids to both stimulate and fuel BAT thermogenesis. Heat produced from BAT is then presumed to transfer to the blood passing through the tissue to protect core body temperature in response to the initiating cold stimulus. However, whether human BAT contains such a vascular system is unknown. The purpose of this study was to characterize the arterial and venous supply to supraclavicular BAT. Six healthy subjects [4 men; age: 30.7 ± 5.8 yrs.; body mass index: 21.7 ± 3.5 kg/m2; total body fat % (dual‐energy x‐ray absorptiometry scan): 23.5 ± 6.2 %] underwent time‐of‐flight magnetic resonance angiography (MRA) of the arterial and venous systems and quantitative fat/water MR imaging (FWMRI) to identify BAT. Angiography images were reconstructed at 0.5×0.5×2.0 mm resolution. FWMRI was performed using a 21‐echo spoiled gradient‐echo sequence, with computation of the fat signal fraction using the manufacturer’s algorithms. FWMRI images were reconstructed at 1.0×1.0×4.0 mm resolution and then resized to match the resolution of the MRA data. The supraclavicular BAT depot was hand‐defined from the apex of the lung to its superior margin in the FWMRI images. Coronal, axial, and sagittal maximum intensity projections (MIPs) of the BAT regions were overlaid onto co‐registered MIPs of the arterial and venous angiograms. In five subjects, there was a single, tortuous branch of the second part of the subclavian artery that supplied the BAT depot; in the sixth subject there was insufficient conspicuity to trace this artery back to the subclavian artery. The arterial diameters ranged from 1.5–2.5 mm. In no case was the artery observed to pass completely through the supraclavicular BAT depot. In two subjects, there was a single 3.5 mm diameter vein returning from the head and passing through the medial portion of the BAT. In the other four subjects, there were 3–4 veins with 2–4 mm diameters that returned from the head and that passed through both the medial and lateral portions of the BAT depot. Individuals with the largest diameter arteries also tended to have the most extensive venous systems. These preliminary data suggest that MRA and FWMRI may be used to quantify the arterial and venous supplies of the human supraclavicular BAT depot. The extensive venous supply to BAT, coupled with the absence of arteries passing fully through this BAT depot, together suggest that the primary thermogenic role of the supraclavicular BAT depot is in rewarming blood returning from the head to the central circulation.

Support or Funding Information

NIDDK/NIH R01‐DK‐105371, NCATS/NIH UL1‐TR000445
A First Report of altered bone microarchitecture in a commonly used mouse model of Alzheimer Disease (5XFAD Tg+)
Authors: Suryadevara Vidyani , Krehbiel Connor J. , Walker Chandler L. , Willis Monte
Published: April 2020

Alzheimer’s disease (AD) is prevalent among 44 million people worldwide and is characterized by dementia and deterioration of cognitive capabilities. An accelerated bone loss (osteoporosis) is found in the early stages of the AD and correlates to the common morbidities observed in AD patients (e.g., hip fractures). We hypothesize that primary AD disease alters the bone structure and biomedical properties through direct and indirect (e.g., systemic crosstalk) mechanisms that are currently unknown. The 5XFAD Tg+ mice are a common preclinical AD model with five human AD‐related mutations, including three mutations in human APP (KM670/671NL, I716V, APP V717I) and 2 in human PSEN1 (M146L (A>C), L286V). These mice express high levels of Aβ42 and develop amyloid pathology and cognitive deficits by around four months. In the present study, we investigated the bone microarchitecture in 10‐month‐old hemizygous 5X FADTg+ compare to age‐ and strain‐matched wildtype controls. Specifically, left femurs were assessed by using mCT (SkyScan 1172, 9 mm resolution) for cortical and trabecular properties in the distal femur metaphysis (1 mm) and mid‐diaphysis regions for trabecular and cortical regions, respectively. Analysis of the 5X FAD Tg+ MALE femur microarchitecture revealed distinct changes in the cortical regions, including a significant reduction in total cross‐sectional area, bone marrow area, cortical thickness, periosteal and endocortical surface compared to wildtype controls. In contrast, the 5X FAD Tg+ FEMALE femur cortical properties were not different from wildtype controls. No change in trabecular microarchitecture was identified in MALE or FEMALE 5X FAD Tg+ mice. The alterations in the male cortical bone marrow area potentially indicate alterations through direct crosstalk with the brain, possibly through Aβ deposition, which is present outside of the brain at ten months, which we are presently investigating. The sex‐dependent effects on bone may be due to altered gender‐related transcription factors, possibly mimicking gender‐dependent changes in Aβ deposition and impaired memory levels.

Support or Funding Information

Lilly Foundation/Indiana Center for Musculoskeletal Health/ IU School of Medicine, Physician Scientist Initiative, Scientific Research Initiative
Documenting Donor Anatomical Variation and Pathology in the Anatomy Lab
Authors: Nesbitt Allison , Johnson Laura E.
Published: April 2020

Anatomy donors are health professions students’ first patients and once‐in‐a‐lifetime teachers. Several institutions have introduced “first patient” humanistic exercises to connect human anatomy with clinical observation skills and for student reflection, including providing deidentified medical history of the donor to the students. For the past several years at the University of Missouri, students have been given personal and medical history provided by the donor at the time of enrollment. However, during the course of dissection, students frequently found anatomical variations and medical pathologies not previously documented by the donor to the program. These medical history discrepancies are partially due to the donor population of the University of Missouri Gift of Body Program, where some donors enroll as early as decades before death. To focus student attention on normal anatomical variation and the donor as a first patient with life history, a donor findings sheet was introduced in the summer of 2019 for a physical therapy anatomy course. On the first day of lab, students were introduced to their donors and were asked to observe and record visible markings, scars, and medical devices, and reason about equipment or procedures. The students briefly discussed the implications of their findings on the daily lives of their donors. Throughout the course, students continued to record anatomical variations, medical devices, and surgical procedures. After each of four units, students rotated anatomy laboratory tables to work with new donors and different classmates. A hand‐off from one table of students to the next was facilitated by the donor findings sheet. When comparing the donor findings sheet with the provided donor medical history, students recorded additional surface anatomy, anatomical variations or medical procedures that had not been reported in donor medical histories for thirteen of the sixteen donors (81%). Medical pathologies and procedures were documented more than anatomical variations. Pacemakers, hysterectomies, mastectomies, and spine conditions were most frequently recorded. Of the three donors with no previous medical history, students recorded medical conditions, surgeries or anatomical variations for two of the three donors. The documentation and discussion of the donor findings help students to see all patients as teachers, encourage exploration of human variation, practice documenting, and apply clinical observation and reasoning skills. Future analyses will incorporate student feedback of their perception of humanism in the anatomy lab, and their role in the documentation of variation and pathology in their donors.

Support or Funding Information

NA
Variation in the Jaws and Teeth of the Amphisbaenian Zygaspis from Southern Africa
Authors: Meza Antonio , Akunne Nnamelu , Bell Christopher J. , Lewis Patrick J.
Published: April 2020

Amphisbaenians are an understudied family of worm‐like reptiles consisting of over 150 extant species in 23 genera. Relatively little is known about the cranial anatomy of the group because most members of the clade are small and poorly represented in collections. With skulls of some species only a few millimeters long, traditional anatomical methods are difficult to use. Collection curators are also hesitant to allow destructive analysis of specimens, because few specimens are generally available. Most modern studies of cranial anatomy of amphisbaenians are based upon high‐resolution X‐ray CT scans. CT scanning is nondestructive and allows for detailed examination of even small elements. Most of those studies remain focused on a single specimen and therefore do not account for variation beyond potential asymmetry in a single specimen. We focus on a collection of specimens from a single genus, Zygaspis, and examine their upper and lower jaws and teeth to better estimate morphological variation within a tightly circumscribed clade of Amphisbaenans. The cranial anatomy of Z. quadrifrons is well described, although the description is based on a single specimen. That baseline description now allows for both inter‐ and intraspecific variation to be estimated by expanding the previous work to include other specimens of Z. quadrifrons and other species in the genus. Here, we examined Z. quadrifrons, Z. vandami, Z. niger, Z. ferox, Z. violacea, Z. dolichomenta, and Z. kafuensis, whose collective distribution spans most of southern Africa from the southern reaches of the Democratic Republic of the Congo and the Tanzania/Mozambique border to southern South Africa. One adult specimen from each species was CT scanned and analyzed with Amira software. We examined over 20 dental and mandibular characters, including tooth count, size, and orientation, the presence or absence of specific teeth and processes, and the morphology of the coronoid articulation with other elements of the mandible. We found significant variation in several features, including apparent variation in replacement teeth. Our preliminary results suggest that inter‐ and intraspecific variation does exist and should be accounted for in functional and phylogenetic studies. Further analysis of the genus, with an increased sample size and broadening to incorporate other cranial variables, would allow enhanced exploration of the morphological variation that occurs within Zygaspis.

Support or Funding Information

Sam Houston State University
Improving Understanding of Immunology for First Year Medical Students
Authors: Morrow Rebekah , Carter Ronda , Brown Jonathan R. , Hamilton Caleb
Published: April 2020

Background

Immunology is a complex field of basic science. Understanding numerous concepts and details is necessary for pre‐clinical medical students to be able to apply immunological concepts to clinical cases and patient care. Faculty in the Hematology and Lymphatics course collaborated to change the way primary immunodeficiencies were taught in an effort to increase comprehension and integration of basic and clinical sciences.

Methods

In previous years, all immunology in the course was taught by basic sciences faculty. To change this approach, we added a lecture by a clinical faculty member which covered important/notable manifestations of primary immunodeficiencies. The basic sciences faculty member continued to emphasize underlying cellular defects that give rise to clinical presentations. We also included a new integrated event (a TBL session) taught by both clinical and basic sciences faculty, in which students were presented with clinical cases and asked to come up with differential diagnoses, explain their rationale and defend their choices, and explain the causes of patient symptoms.

Results

The average score on immunology exam items increased by more than 10 percentage points. Average scores on the exam which included this material increased, while number of exam failures decreased. Student feedback also indicated that this approach was helpful for understanding the material.

Conclusions

Emphasizing clinical correlations in teaching immunology to pre‐clinical medical students resulted in course improvements indicated by both quantitative and qualitative measures.
An Anti‐Racist Classroom in the Natural Sciences
Authors: Grover Neena
Published: April 2020

Most of would like to think of our classrooms as inclusive spaces where all students are provided with the same learning opportunities, with any “perceived” inequities attributed to misunderstandings. Often the focus in the sciences remains on the coverage of the content, the foundational knowledge and how we build on it. Then what does it mean to have an anti‐racist science classroom? Does providing students with examples of diversity among scientists “count”? Does showing students that they too can (potentially) have a place in science qualify as antiracist? To create an anti‐racist classroom requires an examination of our pedagogical approaches, our personalities, our language and our biases. It requires a critical eye toward how we teach, what we value and grade, and it includes who we are as individuals. We have to examine the scientific culture and its myths. We have to learn what we bring with us into the classroom, including the histories and practices of our fields that were (are?) often exclusionary. We have to look at who succeeds and why? Creating classrooms that de‐center the learning from a knowledge‐transfer professor‐centric model to one that engages with real‐life questions can bring diverse perspectives into sciences and enable us to build new models for teaching and learning. Strategies for creating anti‐racist classroom will require open minds and hearts along with a prolonged and sustained effort to undo centuries of oppression.
NIRS‐derived Microvascular Oxygen Saturation Kinetics Related to Skeletal Muscle Metabolic Rate
Authors: Margo Amadea C. , Townsend Dana K. , Hunt Brian E. , Barstow Thomas J.
Published: April 2020

Introduction

Skeletal muscle tissue oxygen hemoglobin/myoglobin saturation (STO2) measured during post occlusive reactive hyperemia (PORH) provides a kinetic parameter (STO2 upslope (%/time)) that has increasingly been used as a measure of microvascular responsiveness. The magnitude of the oxygen saturation prior to cuff release (STO2 min) often correlates to STO2 upslope but the physiological variable associated with variability in STO2 min is most likely muscle metabolic rate (MR). This physiologic variable likely influences the rate of reperfusion after cuff release. The purpose of this study, therefore, was to isolate variables contributing to differences in STO2 upslope through their influence on STO2 min. Our hypothesis was that MR would significantly affect STO2 upslope.

Methods

The anterior antebrachium of twenty‐two (11 male, 11 female), 18–26 years, normoglycemic subjects was monitored continuously by near infrared spectroscopy during three upper limb PORH tests. Tissue oxygenation variables were determined prior to, during the cuff and for 2.5 min. post‐cuff release. MR was calculated in ml O2/100 g lean tissue/min and used both corrected and uncorrected for ATT (MRC). Body fat and abdominal adiposity (%) were quantified by dual energy‐ray absorptiometry. Forearm adipose tissue thickness (ATT) (3.32 + 1.43 mm, range 2.8–6.7 mm) was measured by ultrasound.

Results

STO2 min and STO2 upslope were significantly negatively correlated (r=−0.47, P= 0.03) and both were significantly negatively correlated with MR (r = −0.75, P = <0.001 and r = −0.52, P = 0.01, respectively). In a multiple, forward step‐wise regression analysis with a dependent variable of STO2 upslope and independent variables of ATT, MR or MRC, STO2min, and total body fat, only ATT entered the equation (R squared 0.334, P= 0.006); no other variable statistically added any independent predictive power to the regression equation.

Conclusions

To our knowledge, this is the first study to assess the effects of MR on NIRS STO2 upslope. In contrast to our hypothesis, MR did not affect STO2 upslope but ATT did. This finding suggests that ATT must be taken into account when assuming differences in STO2 upslope reflect differences in microvascular reactivity even in largely lean subjects.

Support or Funding Information

American Heart Association, Grant/Award Number: 0151183ZWheaton College Alumni Summer Research Support
A Novel Model of Long‐term Human Microvascular Endothelial Cell Serum Starvation
Authors: Rossiter Jackie Lee , Yosten Gina , Kolar Grant
Published: April 2020

Microvascular endothelial cell injury and progressive loss of microvasculature in the dermis, kidney, retina and perineural beds is caused by hyper‐and hypoglycemic insults in individuals with Diabetes mellitus (DM). The consequence of microvascular injuries occurring over years to decades is the onset of DM‐associated co‐morbidities such as delayed wound healing, renal failure, vision loss and peripheral neuropathy. The Diabetes Control and Complications Trial noted a correlation between baseline endogenous C‐peptide serum levels and the delay in onset of DM‐associated co‐morbidities. In immortalized human microvascular endothelial cells (HMEC) and primary human dermal microvascular endothelial cells treatment with 1.5nM C‐peptide and 0.5nM insulin prevented hyperglycemia‐induced oxidative injury. In studies of these cells using immunofluorescence to track C‐peptide and the C‐peptide receptor, G‐protein coupled receptor 146 (GPR146), endothelial cells repeatedly demonstrated cytosolic stores of C‐peptide. Fetal bovine serum, a component of almost all cell culture growth media was determined to have high concentrations of C‐peptide. The aim of this study was to develop a model of long term endothelial serum starvation that would result in depleted internal stores of C‐peptide, but would prevent endothelial cells transformation to smooth muscle cells or fibroblasts, as endothelial progenitor cells are capable of differentiating into one of these three cell types. We hypothesized that cytosolic C‐peptide would reduce over time with serum starvation. To test this hypothesis, HMEC were incubated for up to two months in MCDB13 media supplemented with human epidermal growth factor, hydrocortisone, vascular endothelial growth factor, basic fibroblast growth factor, insulin‐like growth factor‐1, ascorbic acid, and L‐glutamine. Serum starved HMEC were harvested at various time points and stained for C‐peptide (MAB80561 R&D Systems clone 915612) and DAPI or lysed with lysis buffer with 2‐mercaptoethanol followed by RNA isolation, cDNA preparation and RT‐PCR evaluation of targets. Cytosolic C‐peptide fluorescent signal diminished over time in a linear manner but was never completely abolished. HMEC serum starved for 30 days retained endothelial markers CD31, CD34, VEGFR2, had no change in smooth muscle markers Smoothelin, or Smooth muscle actin, and similarly, had no change in expression Vimentin a fibroblast marker relative to un‐serum starved HMEC controls as determined by RT‐PCR. The ability to serum starve HMEC long‐term and substantially reduce internal C‐peptide stores has the potential to enhance research to elucidate the pathways employed by C‐peptide in the prevention of hyperglycemia‐induced microvascular injury.

Support or Funding Information

NIDDK
SAP97 mediates local control of cAMP/PKA gradient to regulate L‐type calcium channels in hearts
Authors: Zhao Meimi , Wang Ying , Shi Qian , Xu Bing , Xiang Yang Kevin
Published: April 2020

Rationale

Heart failure as one of the leading causes of morbidity worldwide is hallmarked by dysregulated myocardial calcium (Ca2+) and cardiomyocyte apoptosis. There exists an urgent unmet need of developing novel therapies for preventing and reversing HF progression by correcting Ca2+ dysregulation and inhibiting apoptosis. However, the mechanisms underlying Ca2+ regulation in physiological and pathological conditions remain incompletely elucidated.

Objective

To identify how a synaptic associated protein 97 (SAP97) controls cardiac intracellular Ca2+ in both physiological and HF development.

Methods and Results

We used genetic deletion (cardiomyocyte specific SAP97 knock out mice, SAP97‐cKO) to determine the essential role of SAP97 in regulating the Ca2+ channel activity and how this contributes to the heart failure process. Proximity ligation assay (PLA) and confocal imaging technology were applied to identify a novel SAP97/protein Kinase A (PKA)/ L‐type calcium channel (LTCC) protein machinery complex. We use fluorescence resonance energy transfer (FRET) and living cell imaging to analyze the dynamic spatial changes of Ca2+ homeostasis under the sympathetic adrenergic control of SAP97/LTCC complex. Our study found that a SAP97 binds LTCC and modulates PKA‐dependent LTCC activation via scaffolding PKA and phosphodiesterase 4D8 (PDE4D8) in cardiomyocyte. Disruption of this complex impaired the negative feedback control of cAMP/PKA by PDE4D8, therefore augments PKA‐dependent LTCC activation and promotes Ca2+ dysregulation. Moreover, genetic deletion of SAP97 enhances cAMP/PKA activity and induces Ca2+ dysregulation, which promotes cardiomyocyte apoptosis and HF development in mice.

Conclusion

SAP97 mediated local control of cAMP/PKA gradients regulates LTCC and Ca2+ homeostasis in failing heart, therefore offer a novel SAP97/PKA/Ca2+ signaling axis as a therapeutic target for heart failure prevention and treatment.

Support or Funding Information

This study was supported by NIH grants HL113413 and HL147264 and VA Merit grant 01BX002900 to Y.K.X.
Protein‐DNA Interactomes of NKX2‐5 Mutants Identified in Congenital Heart Defects
Authors: Carrasquillo-Dones Emmanuel Antonio , César Brenda , Rodriguez-Martinez Jose Arcadio
Published: April 2020

Congenital Heart Defects (CHDs) are one of the most common birth defects, with over 100,000 new reported cases each year. CHDs are characterized by malformations in the heart’s chambers, walls and great vessels, sometimes leading to embryonic death. NKX2‐5 is cardiac transcription factors (cardiac TFs) that play a critical role in developmental stages and physiological process of the heart. Transcription factors regulate gene expression via sequence‐specific interactions with DNA. Genetic analyses of CHD patients have identified various non‐synonymous mutations within the DNA‐binding domain (DBD) of NKX2‐5. We hypothesize that non‐synonymous mutations in NKX2‐5’s DBD will alter their DNA‐binding properties ultimately affecting transcriptional pathways necessary for proper heart development. To address this hypothesis, we want to study how the cardiac TFs DNA‐protein interactomes are affected by non‐synonymous mutations found in CHD patients. We have successfully cloned, over‐expressed and purified the homeodomain (HD) DBD of NKX2‐5. Functional analysis protocols using Electrophoretic Mobility Shift Assay (EMSA) confirms protein binding to its DNA binding sites. Additionally, we generated 7 non‐synonymous NKX2‐5 CHD mutants (A148E, E154G, R161P, L171R, T178M, Q181H, R189P) via site directed mutagenesis. Comprehensive protein‐DNA interactomes of NKX2‐5 and its mutants will be determined by Systematic Evolution of Ligands and Exponential Enrichment (SELEX‐seq). Bioinformatics tools will be used predict changes in DNA‐binding preferences and putative gene targets between wild‐type and mutant TFs.

Support or Funding Information

This research was supported: NIH grant award SC1GM127231 Research Initiative for Scientific Enhancement (RISE) Grant #5R25GM061151‐18
Influence of Exercise Modality on the Cerebrovascular Response to Physiological Stressors
Authors: Corkery Adam T. , Pearson Andrew G. , Miller Kathleen B. , Howery Anna J. , Barnes Jill N.
Published: April 2020

Background

Habitual exercise has previously been shown to alter the cerebrovascular response to hypercapnia. Similar to hypercapnia, increases in the brain’s metabolic activity result in local augmentation of cerebral blood flow; however, the mechanisms governing the cerebrovascular response to these two stimuli likely differ. Although, previous studies have examined the influence of aerobic exercise on the cerebrovascular response to hypercapnia, little is known about the influence of habitual resistance training on cerebrovascular function. Therefore, the purpose of this study was to evaluate the cerebrovascular response to both hypercapnia and a metabolic stimulus (cognitive challenge) in resistance trained (RT), aerobic trained (AT), and untrained (UT) adults.

Methods

We recruited 13 RT (women: n = 2, age: 24 ± 4 y), 12 AT (women: n = 2, age: 28 ± 6 y), and 13 UT (women: n = 2, age: 27 ± 5 y) healthy young adults. Middle cerebral artery velocity (MCAv), beat‐to‐beat mean arterial blood pressure (MAP) and end‐tidal carbon dioxide (ETCO2) were continuously monitored during hypercapnia and a Stroop Color and Word Test. Cerebrovascular conductance index (CVCi) was calculated as MCAv/MAP. Reactivity to hypercapnia was calculated as the slope of the relationship between each variable of interest (MCAv or CVCi) and ETCO2. Responses to the Stroop test were calculated as the absolute change from baseline to the 3‐beat peak of each variable during the test.

Results

There were no significant differences in MCAv reactivity and CVCi reactivity to hypercapnia between groups. Despite all groups having a similar change in MAP and ETCO2 during the Stroop test, RT individuals had a greater increase in MCAv (RT: 18.1 ± 1.9 cm/s, AT: 9.7 ± 1.5 cm/s, UT: 15.7 ± 2.0 cm/s; AT vs. RT p < 0.01; AT vs. UT p = 0.07) and CVCi (RT: 0.15 ± 0.02 cm/s/mmHg, AT: 0.08 ± 0.02 cm/s/mmHg, UT: 0.12 ± 0.02 cm/s/mmHg; AT vs. RT p = 0.05; AT vs. UT p = 0.28) compared with AT individuals during the Stroop test. While there was a positive association between the MCAv response to hypercapnia and the MCAv response to the Stroop test in AT individuals (r = 0.67, p < 0.05), and a trend for association in UT individuals (r = 0.49, p = 0.09), there was no relationship between the two variables in RT individuals (r = 0.18, p = 0.56).

Conclusion

While exercise modality did not influence the cerebrovascular response to hypercapnia, it did influence the response to a metabolic stimulus, such that RT individuals had a greater MCAv and CVCi response to a cognitive challenge, compared with AT individuals. Further, exercise modality may influence the mechanisms by which the cerebrovasculature of young adults responds to physiological stimuli.

Support or Funding Information

Supported by National Institute of Health grant HL118154
In vivo metabolomic and lipidomic response of healthy humans to intravenous lipopolysaccharide challenge
Authors: Bresette William , Skulas-Ray Ann Christine , Tontsch Chandra , Tomich Tatiana , Hudson Oneida , Richter Chesney K. , Kris-Etherton Penny M. , Jensen Gordon L. , Chilton Floyd
Published: April 2020

Introduction

Acute inflammation is a complex protective response to injury or infection. However, systemic hyperinflammatory states can lead to septic shock. Lipopolysaccharide (LPS) is a component of gram‐negative bacteria that is widely used for inducing inflammatory responses in animal models. However, many of the critical molecular networks involved in the LPS response in humans remain largely unknown.

Objective

To better characterize the molecular underpinnings of acute inflammation in humans through real‐time biochemical and network appraisals of in vivo challenge with LPS.

Methods

Healthy men were intravenously injected with 0.6 ng/kg LPS at Pennsylvania State University. Plasma markers of inflammation (IL‐6, TNFα, and CRP) were measured prior to and 1, 2, 4, 8, 24, and 72 h post injection. Untargeted metabolomic and lipidomic profiling using liquid chromatography tandem mass spectrometry was conducted on the plasma from 10 men. Deuterated internal standards (SPLASH, Avanti Polar Lipids) were added to plasma to facilitate semi‐quantitative analysis of individual lipid molecular species. Statistics were performed in R (version 1.1.463) and Microsoft Excel (version 16.30).

Results

Of the 1847 metabolites reliably detected, 265 remained significant (FDR‐adjusted p < 0.05) after analysis. Of these metabolites, 197 increased, 51 decreased, and 17 both increased and decreased (depending on the point in the time course). Both metabolomics and lipidomics revealed that molecular species of lipid classes including phospholipids (PL), lyso‐PLs, sphingolipids (SL), diglycerides (DG), and triglycerides (TG) had largest number of metabolites altered after LPS challenge. Notably, levels of 50 lyso‐PLs including lyso‐phosphatidylcholine (PC) and lyso‐phosphatidylethanolamine (PE) molecular species were increased in plasma. Additionally, there were significant elevations in certain PL molecular species representing PC, PE, phosphatidylserine, and phosphatidylinositol. Levels of 29 molecular species of SL increased with the majority representing sphingomyelin and ceramide classes. Neutral lipids including DG and TG were also markedly elevated. Pathway analyses highlighted glycerophospholipid metabolism (p < 0.0001) and sphingolipid metabolism (p < 0.001) as highly significant. These data also suggest the activation of multiple lipases including phospholipase A2, phospholipase C and phospholipase D play a critical role in the inflammatory response induced by LPS.

Discussion

Intravenous LPS injection profoundly alters lipid metabolism in healthy adult men. These data may facilitate the identification of biochemical lipid networks and the development of biomarkers associated with inflammatory health/disease status.

Support or Funding Information

Funding source: NIH R01 AT008621
Pulmonary arterial vasoreactivity changes due to the birth transition and the influence of high altitude gestation in lambs
Authors: Murray Samuel , Hanson Shawn F.L. , Blood Arlin B. , Wilson Sean M.
Published: April 2020

Gestation and birth at high altitude is a risk factor in the development of pulmonary hypertension (PH) in the newborn, which afflicts approximately 6 in every 1000 term births. Prior to birth the pulmonary vasculature has high resistance and low flow, however during the transition at birth the resistance drops rapidly allowing for increases in flow. Previous evidence illustrates that high altitude gestation hinders this transition process, which leads to PH. To begin to understand this process in more depth and the etiology associated with the development of PH with birth at high altitude we tested the hypothesis that high altitude gestation would increase arterial reactivity and decrease vasodilatory capacity in lambs going through birth transition. This was examined in wire myography studies performed on pulmonary arteries isolated from near‐term (139 to 141 days gestation, term = 145) fetal lambs that gestated at high altitude (3801 m) for 110+ days or at low altitude (700 m). Ewes were anesthetized with isoflurane and lambs were delivered by C‐section and immediately sacrificed or underwent experimentally‐induced birth transition. Birth‐transition lambs were instrumented with an arterial catheter and endotracheal tube and delivered via C‐section, anesthetized with ketamine (1 mg/kg boluses every hour), and mechanically ventilated with an FiO2 of 30% for three hours. Arterial PO2 and PCO2 were maintained within normal newborn ranges by adjusting tidal volumes and ventilator rate. Lungs were harvested from near term and birth transition lambs and arteries isolated for wire myography. In the wire myography studies evaluations were made of electromechanical coupling by contracting arteries with 125 mM KCl (High K), pharmacomechanical coupling by exposing arteries to additive concentrations of serotonin (5‐HT), and vasodilatory capacity with S‐Nitroglutathione (gSNO), a biologically relevant source of NO. High altitude gestation reduced arterial reactivity to High K and 5‐HT in near term fetuses while birth transition reduced arterial reactivity in low altitude but not high altitude animals. The potency for 5‐HT was diminished in animals that went through birth transition. Dilatory capacity to gSNO was impaired by high altitude gestation but unaffected by the birth transition. These data suggest that the birth transition preferentially reduces constrictor pathways and that dilatory pathways are well developed at the time of birth. High altitude gestation then reduces both contractile as well as dilatory capacities, paralleling other data suggesting high altitude gestation causes cellular immaturity.

Support or Funding Information

Supported in part by NIH grant HD083132 (ABB), HD098477 (SMW)