bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glucagon‐like peptide‐1 mediated renal sympathetic activation in obese rats: role of intrarenal mechanisms
Authors: Zheng Hong , Liu Xuefei 
Published: April 2020

Accumulated evidence indicates that obesity is associated with enhanced sympathetic activation. Chronic sympathetic activation increases the risk of cardiovascular complications and subsequent mortality. The mechanisms linking obesity with sympathetic activation are complex and not completely understood. Gut produced hormone glucagon‐like peptide‐1 (GLP‐1) affects cardiovascular function via regulating blood pressure and sympathetic nerve activity. The aim of the study was to determine the role of intrarenal GLP‐1 mediated renal sympathetic activation in obese rats. In anesthetic Sprague Dawley rats, renal intra‐pelvic infusion of GLP‐1 receptor agonist exendin‐4 increased afferent renal sympathetic nerve activity (A‐RSNA), efferent renal sympathetic nerve activity (T‐RSNA), arterial pressure and heart rate. All the sympathetic and hemodynamic responses to the exendin‐4 infusion were significantly enhanced in high fat diet (HFD, 42% of calories from fat for 12 weeks) induced obese rats. The natriuretic and diuretic effects mediated by intrarenal exendin‐4 infusion was significantly blunted in the obese rats. Furthermore, ablation of renal sympathetic nerves significantly improved the diuretic and natriuretic responses to exendin‐4 infusion in obese rats. We also found significant altered GLP‐1 level and GLP‐1 receptor expression in the kidney of obese rats. The results suggest that altered intrarenal GLP‐1 mediated mechanisms may contribute to the development of obesity‐related high sympathetic activation and obesity hypertension.Support or Funding InformationThe study was supported by the author’s faculty start‐up fund from Sanford School of Medicine of the University of South Dakota Department of Basic Biomedical Sciences.
Effects of water deprivation on inhibitory GABAergic synaptic transmission in the hypothalamic paraventricular nucleus (PVN)
Authors: Yamaguchi Junya , Andrade Mary Ann , Truong Tamara , Toney Glenn M. 
Published: April 2020

Presympathetic neurons (PSNs) of the hypothalamic PVN mostly lack basal firing in unstressed animals due to the dominance of GABAergic inhibition, which our findings indicate is actively promoted and defended by the coupling of synaptic glutamate (Glu) release to heightened synthesis and packaging of GABA into synaptic vesicles. Our findings indicate that the latter process, referred to as Glu‐GABA strengthening (GGS), depends on EAAT3‐mediated uptake of Glu into PVN GABA terminals. To investigate the impact of PVN GGS on PSN responses to short‐term exposure to a physiological challenge that increases glutamatergic excitation of the PVN, male C57Bl/6 mice were either euhydrated (EUH) or water deprived (WD) for 48 h. Western blot analysis revealed significantly increased (P<0.05) PVN EAAT3 in WD (132 ± 1.2%) compared to EUH (100 ± 9.5 %) mice (n=18/group). Together with our previous report of reduced PVN expression of the glial Glu transporter GLT‐1 (EAAT2) in WD rats, the present findings suggest that Glu clearance in the PVN is shift during dehydration to favor uptake by neuronal EAAT3. If true, this could indicate that PVN GGS becomes enhanced during dehydration. To explore this further, we determined in brain slices from WD mice (n=4) that the amplitude of evoked IPSCs at baseline (−397 ± 102 pA) was unaffected by bath exposure to Glu (100 μM, 10 min) (−352 ± 89 pA), indicating either that dehydration disrupts PVN GGS or enhances it nearly to its maximum. To distinguish between these possibilities, we generated a cumulative eIPSC amplitude curve from 1000 stimuli delivered at a frequency of 5 Hz to the GABAergic peri‐nuclear zone (PNZ) that surrounds the PVN. The slope (‐pA/stimulus) of this relation in WD mice early during the stimulus train (stimuli 1–100) was similar to that of mice lacking GGS due to EAAT3 knockdown (KD) in PNZ GABA neurons (WD: 186 ± 0.9, EAAT3 KD: 180 ± 0.9). By contrast, the late phase slope (stimuli 901–1000) was 3 time higher for PSNs from WD mice than from the PNZ EAAT3 KD group (WD: 52 ± 0.2, EAAT3 KD: 17 ± 0.1). The latter indicates that eIPSCs in the WD group are resistant to rundown/depression and suggests that PVN GGS is likely near maximally enhanced, not disrupted, during dehydration. We posit that enhanced PVN GGS may be critical for preserving synaptic homeostasis and preventing excessive PSN activation and sympathoexcitation during short‐term dehydration stress.Support or Funding InformationNIH HL088052 (GMT)
Exploring the Role of Mitochondrial ClpP Activators on Immune Signaling in Breast Cancer
Authors: Aponte-Collazo Lucas J. , Fennell Emily M.J. , Graves Paul R. , Herring Laura , Iwanowicz Edwin J. , Holmuhamedov Ekhson , Graves Lee M. 
Published: April 2020

Approximately 20% of breast cancer cases diagnosed yearly are of the triple‐negative breast cancer (TNBC) type. Current treatments for TNBC patients are limited to surgical intervention and traditional chemotherapies. ONC201 is a recently discovered orally‐active imipridone molecule in phase I/II clinical trials for a large variety of aggressive cancers including glioblastoma, breast, endometrial, and others. We have been studying highly potent analogs of ONC201, known as the TR compounds (TRs), for their efficacy in TNBC. To better understand the mechanism of action, we coupled a TR compound to agarose beads and applied proteomics to identify potential targets. Our studies identified the mitochondrial caseinolytic peptidase (ClpP), as a major ONC201 and TRs binding protein. We further demonstrated that these compounds activated the proteolytic activity of ClpP and that this mitochondrial signal was required for subsequent activation of the integrated stress response as determined by increased CHOP and ATF4 proteins. In addition to activation of the integrated stress response, other recent studies have suggested that the antitumor effects of ONC201 may in part be dependent on increased immune cell recruitment and cancer growth inhibition through this mechanism. Thus, one of our major objectives is to understand how activation of ClpP by ONC201 or TRs impacts cellular signaling events that lead to enhanced immune cell recruitment. We hypothesize that activation of ClpP promotes activation of key immune signaling proteins, like NF‐kB, which subsequently leads to an increase in proteins required for immune cell recruitment. Accordingly, our preliminary data shows activation or up‐regulation of proteins connected to innate immune signaling including MAVS, NF‐kB, and TBK1 in response to ONC201 or TRs treatment. Additionally, our qPCR data shows that treatment of TNBC cells with ONC201 or TRs leads to increased mRNA levels of specific Interleukins (IL‐12, IL‐10). Collectively, these results suggest that activation of ClpP by ONC201 or TRs increases innate immune signaling and expression of cytokines, which are crucial events for successful recruitment of immune cells. Future experiments will evaluate if activation of NF‐κB by ONC201 or TRs treatment is ClpP dependent using a ClpP knockout in TNBC cell lines. Lastly, we will also measure changes in levels of known NF‐κB regulated cytokines (TNFα, IL‐6, IL‐18 and IL‐1β) after treating TNBC cells with ONC201 or TRs using flow cytometry. Overall, this work provides valuable new insight into potential mechanisms by which ClpP activators mediate their anti‐cancer effects through immune signaling and recruitment.Support or Funding InformationL.J.A.‐C was supported by the NIH 5 T32 GM007040
Femoral condyle dimensions: comparing natural anatomy to knee replacement hardware
Authors: Horbaly Haley Elizabeth , Auerbach Benjamin Elizabeth 
Published: April 2020

Orthopedics companies have recently pursued sex‐specific total knee replacement (TKR) designs that account for sexual dimorphism to improve post‐operative outcomes for females. Prior research on knee anatomy has shown no significant differences in morphology between the sexes when controlling for size. For knee replacements to be effective they must functionally mimic natural skeletal anatomy, yet the variance in TKR appliances in relation to skeletal variation has not been thoroughly studied. The question remains if scaling knee replacement appliances to the individual sufficiently reflects the functional variation of knee morphology, or if additional variation in shape must be taken into account.This research analyzes 14 bilateral landmarks on the distal femur and orthopedic hardware for 17 individuals who received unilateral TKRs and 36 control individuals with no TKRs. Landmarks reflect the morphology of the distal articular surfaces, including dimensions of the condyles and their relative spacing. Ten interlandmark distances (ILDs) were extracted for analyses. We performed principal components analysis on the pooled sample. PC1 (63% of variance) describes size differences; all ILDs positively relate to it and it separates females from males. PC2 (14% of variance) indicates that measurements reflecting condylar morphology are inversely related to intercondylar measurements (overall condylar breadth, intercondylar width [ICW], and proximal and distal intercondylar distances [PID, DID]). Of these traits, ICW, which has the weakest relationship with body size, exhibits the strongest association with PC2. Further exploration of intercondylar measures reveals that PID and DID dimensions are significantly different (p<0.05) in males. An ANCOVA reveals that these two dimensions have different scaling relationships, which indicates the medial condyle deviates from a proximodistal orientation (increases its angle) with increased body size. PID and DID are comparable distances in the TKR hardware (p = 0.327) and pooled females (p = 0.159). Overall, no sexual dimorphism is present in the dimensions of the distal femur when accounting for size, and bilateral asymmetry in individuals with unilateral TKR is not outside the range of normal human variation. The only exception is that males show medial condyle asymmetry between their natural femur and replacement hardware. Further, the comparably‐sized PID and DID dimensions in femoral implants mimic the pattern observed in females, while males show significant differences in these dimensions. This analysis indicates that traditional unisex hardware dimensions may be more similar to female distal femur anatomy, and is likely not contributing to reduced post‐operative outcomes for females.
Nanolipoprotein Particles (NLPs) as an In Vivo Delivery Platform for Biomedical Applications
Authors: Gilmore Sean F. 
Published: April 2020

Nanoparticles hold great promise for the delivery of therapeutics. One emerging class of these materials are nanolipoprotein particles (NLPs), which are mimetics of naturally occurring high‐density lipoproteins (HDLs). NLPs are attractive for drug or vaccine formulation since they: (1) can be loaded with hydrophobic “cargo” molecules, (2) have high water solubility and (3) are easily modified for targeted delivery to specific tissues. However, their widespread adoption has been limited by poor in vivo stability, likely due rapid exchange with lipoproteins in blood. We report herein progress towards loading NLPs with several classes of therapeutically relevant molecules and drastic improvement of NLP in vivo stability. Additionally, we have evaluated the functionality, stability, cytotoxicity, toxicity, immunogenicity and in vivo biodistribution of NLPs. We found that a wide range of molecules with disparate chemical properties could be reliably conjugated to NLPs, including proteins, single‐stranded DNA, vaccine adjuvants, and small molecule drugs including chemotherapeutics. We also report an optimized NLP formulation that is highly stable in blood serum, with a half‐life greater than 24 hrs and no cytotoxicity to human cell cultures at doses as high as 320 μg/ml. As NLPs are constructed from lipids and recombinant, truncated apolipoproteins, we report that these particles do not possess any inherent immunogenicity. Biodistribution of the particles is route dependent, but when administered intravenously to mice, we observe uptake into the brain as measured through accelerator mass spectrometry. These findings are supportive of NLPs as a versatile platform that holds promise for use as a delivery vehicle for a range of therapeutics.Support or Funding InformationThis work was funded by LLNL awards 15‐LW‐023 and 17‐LW‐051.
The Shape Solidity of the Glenoid Fossa of the Scapula is Sexually Dimorphic: A New Approach to Understanding the Glenoid Fossa
Authors: Bolden Alexys M. , Burkett Jesse T. , Shockley J. Mason , Alsharaf Fatemah , Zdilla Matthew J. , Lambert H. Wayne 
Published: April 2020

Sexual dimorphism in the size of the glenoid fossa of the scapula is well‐established; however, there remains little information with regard to differences in glenoid shape between sexes. Therefore, this study assessed 71 glenoid fossae from dry scapula. Three differential equations were utilized to ensure that scapulae were appropriately sexed and, accordingly, included in the study. When all three equations were in agreement with regard to sex, the scapula was included for study. A total of 64 scapulae (45 females and 19 males) met inclusion criteria. Shape parameters that were assessed included circularity (4π*area/perimeter2), roundness (4*area/π*major axis2), aspect ratio of a bet‐fit ellipse (major axis/minor axis), and solidity (area/area of a convex hull). Shape parameters such as circularity, aspect ratio, and roundness were not significantly different between sexes; however, solidity was significantly different between females and males (p=0.0475). The results demonstrate a difference in the concavity of the boundary of the glenoid fossa between sexes. Further study should elucidate the functional differences in glenohumeral joint biomechanics with regard to the solidity of the glenoid fossa while taking sex into consideration.Support or Funding InformationWV Research Challenge Fund [HEPC.dsr.17.06]
Effects of in Vitro Exercise‐Induced Endothelial Shear Stress on Oxidative Stress and Vasoconstriction Gene Expression
Authors: Garcia Mario , Morales-Acuna Francisco , Conde Daniel , Gurovich Alvaro N. 
Published: April 2020

BackgroundSedentary lifestyle contributes to endothelial dysfunction through increasing oxidative stress and endothelin‐1, a potent vasoconstrictor that contributes to the pathogenesis of vascular disease. Exercise‐induced endothelial shear stress (ESS) elicits a mechanical stimulus leading to intracellular signaling transduction regulating cellular function that might protect against endothelial dysfunction through promotion of the expression of anti‐oxidative and pro‐vasodilatory genes. Although it has been reported that increments on steady ESS has led to improvements in endothelial function in vivo, the role of pulsatile exercise induced ESS and varying exercise intensities in vitro has not been explored yet. Therefore, the purpose of this study was to determine the effects of pulsatile exercise‐induced ESS based on in vivo exercise intensity on anti‐oxidative (superoxide dismutase, SOD2) and vasoconstrictive (endothelin 1, EDN‐1) gene expression.MethodsCommercially available human carotid artery endothelial cells (Sigma‐Aldrich Comp.) were cultured until 95–100% confluence and exposed to pulsatile resting ESS (18 dynes/cm2) for 5 hours, followed by 1 hour at resting ESS, low‐intensity exercise‐induced ESS (35 dynes/cm2), or high‐intensity exercise‐induced ESS (80 dynes/cm2) on parallel fluidic units (Ibidi USA, Inc.). Ibidi pump software (PumpControl Software 1.5.4) was used to control shear stress intensity. Total RNA was extracted and reverse transcribed followed by measurement of EDN‐1 and SOD2 mRNA expression via qRT‐PCR. qRT‐PCRs were performed in duplicates and changes in gene expression were calculated using the ΔΔ‐CT method with GAPDH used as the normalizing control gene. Statistical analysis was performed using graphpad prism 8 software (Graphpad Software.). Significance was considered at p<0.05.ResultsmRNA expression of SOD2 increased 2.5‐fold after exposure to low‐intensity exercise‐induced ESS (p<0.05). EDN‐1 showed a 5‐fold increase following exposure to low‐intensity exercise‐induced ESS (p<0.05) in comparison to resting conditions. High‐intensity pulsatile exercise‐induced ESS decreased the expression of EDN‐1 in comparison to resting and low‐intensity conditions (p<0.05).ConclusionPulsatile exercise‐induced ESS improved anti‐oxidative properties in human carotid artery endothelial cells. It seems that higher exercise intensities are required to downregulate the expression of vasoconstrictive genes.
Lipid composition and organization helps plasma membrane repair and offers novel therapeutic target to treat degenerative muscle disease
Authors: Jaiswal Jyoti K. , SenChandra Sreetama , Bittel Daniel , Horn Adam 
Published: April 2020

The plasma membrane of all cells is routinely injured, with considerable investigative effort focused on understanding how proteins help repair this injury. Despite being the most abundant component of the plasma membrane, the role of lipids in repairing injured mammalian cells has remained unexplored. Through systematic live cell imaging we have examined the involvement of lipids in plasma membrane repair following injury. This shows that change in composition and localization of plasma membrane lipids is crucial for repair. Specifically, we find that cell injury results in a rapid change in local cholesterol and sphingomyelin content, and failure of which increases membrane fluidity and compromises membrane repair. Plasma membrane injury also alters the local composition of phospholipids including PIP2 and diacylglycerol (DAG), which is required for the repair of the injured plasma membrane. Failure of these lipid changes in muscle fibers injured by mechanical or other activity, results in myofiber death and Limb Girdle Muscular Dystrophy (LGMD2B). To target this deficit we developed a gene therapy approach to exogenously modify the plasma membrane lipid composition in a mouse model of LGMD2B. This approach improved the repair of the dystrophic muscle, attenuated myofiber death and improved muscle strength and histopathology. These findings provide direct evidence of the diverse roles of lipids in not only maintaining the integrity of the plasma membrane, but also in re‐establishing its integrity following injury. Here, we establish the clinical relevance of the structural and signaling roles of lipids in cell repair, and identify therapeutic approaches that address these deficits in muscle diseases.Support or Funding InformationThis work is supported by R01AR055686 from NIH/NIAMS.
Independent and Combined Effects of Bisphenol A and Diethylhexyl Phthalate on Gestational Outcomes and Offspring Development in Sprague‐Dawley Rats
Authors: Dagher Josephine Bou , Campbell Elyssa , Kaimal Amrita , Hahn-Townsend Coral , Al Mansi Maryam Hazim , Tran Diane , Laurent Christian , Bacak Caleb , Cambric Celexis , Henriquez Joseph , Spivey Jared , Buechter Hannah , Chuang Yen-Jun , Mohankumar Puliyur , Mohankumar Sheba 
Published: April 2020

BackgroundBisphenol A (BPA) and Diethylhexyl Phthalate (DEHP) are common plastic‐derived environmental contaminants that act as endocrine disrupting chemicals (EDCs) and pose risks for expecting mothers and offspring. Research addressing the effect of a mixture of these EDCs is limited.ObjectiveTo assess the sex‐specific consequences of developmental exposure to individual as well as mixtures of environmentally relevant doses of BPA/DEHP in male and female Sprague‐Dawley rats.MethodsFrom gestational day 6 till 21, dams were orally administered either saline (control), BPA (5mg/Kg BW/day), low‐dose (LD) DEHP (5mg/Kg BW/day), high‐dose (HD) DEHP (7.5 mg/Kg BW/day), a combination of BPA and LD DEHP (B+LD‐D), or a combination of BPA and HD DEHP (B+HD‐D). Gestational weights and number of abortions were tracked. Litter size and weights, number of live births and stillbirths were counted. Morphometric parameters at birth were measured. Body weighs, food and water intakes were monitored weekly from postnatal weeks 3–12. Male and female offspring were sacrificed at 16–24 weeks of age and organs were dissected and weighed.ResultsThe abortion rate of dams exposed to HD DEHP and the mixtures, B+LD‐D and B+HD‐D were higher at 8, 14 and 23% respectively. Gestational index was reduced in these groups as well. Prenatal exposure to BPA or HD DEHP significantly decreased relative thymus weight in male but not female offspring at 16 weeks. Relative heart weight increased in B+HD‐D exposed male offspring compared to the other groups. No programming effects in relative organs weights were detected in female offspring.ConclusionThe results indicate that a mixture of BPA and DEHP, even at low doses, induced a pronounced effect on pregnancy outcomes. Male offspring appear to be more susceptible to the programming effects of these EDCs or their mixture. This suggests a great need to reconsider the possible additive, antagonistic or synergistic effects of EDC mixtures to which pregnant individuals are commonly exposed to.Support or Funding InformationSupported by UGA research foundation.