bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autonomic Dysregulation in Adolescent Concussion: Characterization and Temporal Resolution of Neurological Outcomes
Authors: Balestrini Christopher S. , Moir M. Erin , Abbott Kolten C. , Johnson Marjorie , Fischer Lisa K. , Fraser Douglas D. , Shoemaker J. Kevin 
Published: November 2023

Although incidence is at epidemic levels, objective indicators of neurologic damage in adolescent concussion remain poorly described. Autonomic markers such as heart rate variability (HRV) have provided equivocal results; however, these predominantly are made under conditions of minimal physiologic stress. The current investigation employs postural stressors to examine underlying neurological outcomes associated with acute concussion and clinical recovery to test the hypothesis that concussion impairs dynamic autonomic adjustments in adolescents. We examined concussed adolescents (CONC; n = 35; 14 males; age 15 ± 1 yrs, range = 12–18 yrs) for up to 6 weekly visits from diagnosis. A group of age and activity level‐matched non‐concussed adolescents (CTRL; n = 35; 19 males; age 14 ± 2 yrs, range = 12–18 yrs) formed the reference control. HRV (root mean square of successive differences in R‐R intervals (RMSSD)) and heart rate were assessed during a sit‐to‐stand protocol (two trials of seated posture (three minutes), followed by two minutes of standing). Measurements were taken during the last minute of sitting and standing, the ten second period following the postural stress of standing, as well as the ten second period from maximum HR. While seated, RMSSD was lower in CONC (41 ± 24 msec) compared with CTRL (60 ± 40 msec; p < 0.05). 31 patients provided weekly data until clinical discharge. Compared with the first visit (43 ± 25 msec), seated RMSSD in CONC increased (51 ± 36 msec; p = 0.05) at the time of clinical discharge. Upon standing (10 seconds following postural change to standing), RMSSD was lower in CONC versus CTRL (13 ± 7 vs. 18 ± 12 msec; p < 0.05). Compared with the first visit, RMSSD following the induced postural stress did not improve in CONC over the six week recovery period. Following maximal HR, CTRL had increased RMSSD versus CONC (46 ± 30 vs. 34 ± 19 msec; p < 0.05). Compared with CTRL, seated HR was higher in CONC. This tachycardia effect persisted throughout the sit‐to‐stand protocol (78 ± 12 vs. 72 ± 12 bpm; p < 0.05) and was maintained until the time of clinical discharge (79 ± 13 vs. 72 ± 12 bpm; p < 0.05). In adolescent concussion, autonomic cardiac impairment is demonstrated by reduced RMSSD in the seated position and throughout the adjustment period in response to postural stress. Further, seated HR is increased following acute concussion and remains elevated by the time of clinical discharge. Seated HRV, but not HR, recovered to levels seen in the control population within three to six weeks. Thus, cardiac adjustments to modest postural stress may represent a measurable neurological impairment in adolescent acute concussion which can be objectively monitored throughout clinical recovery.Support or Funding InformationResearch supported by the Children's Health Research Institute (London, Canada).
L‐arginine Infusion Reduces Muscle Sympathetic Nerve Activity and Blood Pressure in Patients with Chronic Kidney Disease
Authors: Kaur Jasdeep , Vranish Jennifer R. , Fadel Paul J. 
Published: November 2023

An overactive sympathetic nervous system is a known cardiovascular risk factor present in chronic kidney disease (CKD) patients. However, limited effort has been directed at identifying the mechanisms contributing to sympathetic overactivity in CKD. Herein, we examined a potential role for accumulation of the endogenous nitric oxide (NO) synthase inhibitor asymmetric dimethylarginine (ADMA) in driving the high sympathetic nerve activity (SNA) present in CKD. ADMA is elevated in CKD and is a strong, independent predictor of future cardiovascular events in these patients. Much of the work with ADMA has been correlational in nature with a focus on the well‐known vascular endothelial properties of nitric oxide. However, increasing functional evidence indicates that NO is also a key signaling molecule involved in the tonic restraint of sympathetic outflow from the brainstem. Thus, it is possible that NO synthase inhibition with elevated endogenous ADMA contributes to sympathetic overactivity in CKD patients. We tested the hypothesis that overcoming accumulation of endogenous ADMA with acute L‐arginine infusion reduces sympathetic overactivity in CKD patients. In 5 hypertensive CKD patients, muscle SNA (peroneal nerve microneurography), blood pressure (BP; finger photoplethysmography), and heart rate (ECG) were measured before, during, and 45 minutes after systemic intravenous infusion of L‐arginine, the natural substrate for NO synthase, at a dose of 250 mg/kg over 20 minutes. Following L‐arginine infusion, mean BP was reduced (111±4 mmHg, baseline vs. 105±4 mmHg, L‐arginine; P=0.009). Likewise, MSNA was significantly decreased with L‐arginine (70±4 bursts per 100 heart beats, baseline vs. 59±6 bursts per 100 heart beats, L‐arginine; P=0.023). The concomitant decrease in MSNA and BP strongly implicates a central sympathetic effect of L‐arginine. If L‐arginine was only restoring peripheral NO production, the endothelial‐mediated reduction in mean BP due to peripheral vasodilation would be accompanied by an arterial baroreflex‐mediated increase in MSNA. These preliminary findings of simultaneous reductions in MSNA and BP suggest that L‐arginine restores central NO production in CKD patients supporting a role for ADMA in mediating sympathetic overactivity and hypertension in CKD patients.Support or Funding InformationNIH R01 HL127071
Role of the OVLT in the Development of DOCA‐salt Hypertension
Authors: Collister John P , Nahey David B , Banek Christopher T , Osborn John W 
Published: November 2023

Lesions of the anteroventral third ventricle (AV3V region) are known to prevent many forms of experimental hypertension, including mineralocorticoid (DOCA‐salt) hypertension in the rat. However, AV3V lesions include the organum vasculosum of the lamina terminalis (OVLT) and portions of the median preoptic nucleus, as well as efferent fibers from the subfornical organ (SFO), thereby limiting the ability to define the individual contribution of these structures to the prevention of experimental hypertension. Having previously reported that the SFO does not play a significant role in the development of DOCA‐salt hypertension, the present study was designed to test the hypothesis that the OVLT is necessary for DOCA‐salt hypertension in the rat. In uninephrectomized OVLT lesioned (OVLTx; n = 4) and SHAM (n = 3) Sprague‐Dawley rats consuming a 2% NaCl diet and 0.9% NaCl drinking solution, 24‐hour mean arterial pressure (MAP) was recorded telemetrically 5 days before and 21 days after DOCA implantation (100 mg/rat; SQ). No differences in control MAP were observed between groups. The chronic pressor response to DOCA was attenuated in OVLTx rats such that MAP increased to 132±4 mmHg in SHAM rats by Day 21 of DOCA compared to 123±4 mmHg in OVLTx rats. These results support the hypothesis that the OVLT is an important brain site of action for the pathogenesis of DOCA‐salt hypertension in the rat.Support or Funding InformationUniversity of Minnesota Academic Health Center Grant 15.05
Compartment‐Specific Effects of Alveolar Heparan Suflate Shedding after Intratracheal Lipopolysaccharide
Authors: Haeger Sarah , Yang Yimu , Ford Joshay , Zhang Fuming , Suflita Matt , Dedent Alison , Zemans Rachel , Tuder Rubin , Schmidt Eric 
Published: November 2023

Acute lung injury can occur as a consequence of direct (pulmonary) insults that target the alveolar epithelium or indirect (extrapulmonary) insults that injure the alveolar endothelium. During indirect lung injury, the endothelial glycocalyx is degraded, releasing highly‐sulfated heparan sulfate (HS) octasaccharides into the vasculature. In contrast to indirect lung injury, it is unknown whether direct lung injury induces release of HS from the apical surface of the damaged alveolar epithelium or the luminal endothelial glycocalyx. We hypothesized that during direct lung injury HS would be shed from injured epithelium, and aimed to determine the function of the shed HS.To determine if HS was shed from the alveolar epithelium into the airspace or from the luminal endothelium into the vasculature, we intratracheally (IT) instilled mice with lipopolysaccharide (LPS) and performed mass spectrometry for HS on bronchoalveolar lavage fluid (BALF) and plasma collected from these mice. We measured increased BALF HS in mice treated with IT LPS vs PBS on day 2 (24.5 vs 6.5ng/ml) and day 4 (18.8 vs 7.5ng/ml) after injury. There was also a trend of increased plasma HS in mice treated with IT LPS vs PBS 4 days after injury (106.8 vs 63.9ng/ml, p = 0.10). We next aimed to determine the function of the shed HS within both the airspace and the vasculature by supplementing mice with exogenous IT or IV heparin octasaccharides (a heavily sulfated HS fragment) on days 2 and 4 after IT LPS injury. Mice supplemented with IV heparin octasaccharides vs PBS on day 2 after injury were protected from injury, exhibiting decreased lung permeability (BALF protein: 0.34 vs 0.40mg/ml) and inflammation (BALF total cells: 3.14 vs 5.63×106). In contrast, animals treated with IT heparin octasaccharides on day 4 after injury exhibited a trend of increased lung permeability (BALF protein: 0.23 vs 0.20mg/ml, p=0.07). Our data indicate that during direct lung injury HS is largely shed from the damaged epithelium, but may also be shed from the endothelium. While intravascular HS is pro‐reparative and decreases injury, airway HS surprisingly appears to exacerbate injury and reduce repair. We are currently investigating the mechanisms by which IT and IV heparin affect lung injury.Support or Funding InformationNHLBI RO1 HL125371NHLBI F30 HL132424
Examination of the Physiological Effects of Ethylene Glycol Exposure on Muscle and Liver Tissue of the Leopard Frog, Rana pipiens
Authors: Funk Alexander N , Stabenau Erich K 
Published: November 2023

Newly developed and utilized industrial processes use anthropogenic agents that may adversely affect ecosystem biodiversity. Hydraulic fracturing technology involves the use of a fluid, composed of 98–99% water and 1–2% chemical additives, to break up shale reservoirs for access to natural gas and oil reserves. One of the chemical additives in fracturing fluid is ethylene glycol. To date, there is no information available of the effects of ethylene glycol exposure on aquatic organisms at concentrations used by the hydraulic fracturing industry (i.e., 0.14–15.8 mM). Therefore, the present study examined the physiological effects of ethylene glycol exposure on Leopard frogs, Rana pipiens. Frogs were exposed to control water or to water containing 5.7 mM ethylene glycol for five days. Ethylene glycol‐exposure significantly decreased the swimming time to exhaustion from 284.5±22.8 sec in control animals to 194.8±26.3 sec (P≤0.05, n=6 in each group). Moreover, contraction of isolated gastrocnemius muscles was significantly less in ethylene glycol‐exposed frogs at 3, 6, 12 and 24 V when compared to control animals. Mitochondrial membrane potential was also significantly decreased in ethylene glycol‐exposed frogs when compared to control animals, decreasing 40.1% and 42.4% in liver and muscle tissue, respectively. Culture of isolated satellite cells from skeletal muscle resulted in a dose‐dependent, ethylene glycol‐induced increase in cell proliferation and differentiation. Taken together, these data indicate that 5.7 mM ethylene glycol significantly reduced muscle and liver performance. Moreover, the activation and proliferation of the satellite cells when exposed to ethylene glycol suggests that the hydraulic fracturing agent is myotoxic to frog muscles. We believe that the agent is altering mitochondrial function by reducing the available ATP for cellular or organ system processes like cell volume regulation and muscle contraction.Support or Funding InformationThis research was supported by grants from Beta Beta Beta, the Bradley University Biology Department and the Bjorklund Endowment, and a Caterpillar Master's Fellowship to ANF.
Mouse prostate organoids as a model for prostate cancer
Authors: Foley Justin A , Shah Kalpit , Bradbury Neil A. 
Published: November 2023

Prostate cancer affects around 14% of men in their lifetime, and is the second leading cause of cancer deaths among the male population. Prostate cancer arises from the epithelial cells of the prostate, and is associated with unregulated activation of the androgen signaling pathway (androgen receptor and associated co‐factors), leading to enhanced expression of androgen dependent genes (e.g., PSA, VEGF) and unregulated cell proliferation. Initially, androgen depravation therapy slows the rate of cancer growth, but this eventually leads to a so‐called androgen‐independent prostate cancer in which cancers are immune to further androgen depletion. Heretofore, research on prostate cancer has relied on the use of prostate cell lines or cells heterologously transfected with androgen signaling components. As these are cancerous or immortalized cell lines, their recapitulation of the native tissue is not always clear. We have previously shown that loss of the kinase LMTK2 is seen in prostate cancer, and is associated with enhanced expression of androgen dependent genes. We have retrieved primary prostate epithelial cells from wt and LMTK2−/− mice. These cells grow and divide in culture and are responsive to androgens. Moreover under low attachment conditions in a 3‐D matrix, the cells form organoids (prostanoids) that display many of the features of native tissues. Our studies reveal prostanoids to be a viable model for normal and cancerous prostate tissues. Indeed, they provide an excellent model for evaluating the physiology of LMTK2 kinase activity within a physiologically relevant context. In addition they provide a rational model for the evaluation of pharmacological agents aimed at treating individuals with prostate cancer.Support or Funding InformationNIH R01HL102208
Obesity, Independent of the Type of Diet, Drives Lasting Effects on Intestinal Epithelial Stem Cell Proliferation
Authors: Zhou Weinan , Blackmore Katherine , Feldner Mary Kate , Dailey Megan J. 
Published: November 2023

The intestinal epithelium plays an essential role in nutrient absorption, satiety hormone release and immune barrier function. Maintenance of the epithelium is driven by continuous cell renewal by intestinal epithelial stem cells (IESCs) located in the intestinal crypts. Obesity affects this process and results in changes in the size and cellular make‐up of the tissue. In addition, isolated IESCs from obese mice have a reduced growth potential to develop into organoids in culture compared with IESCs from lean mice, indicating that obesity may produce long‐lasting effects on IESC proliferation and differentiation. Because the amount and type of diet contribute to obesity, we wanted to determine whether the amount (in kilocalories) or type of diet differentially alters IESC proliferation. C57BL/6J mice were fed two different diet combinations, a high‐fat diet or a Westernized high‐fat/high‐sugar diet. The high‐fat and control groups were as follows: 1) 60% high‐fat fed, 2) 10% low‐fat fed, and 3) 60% high‐fat pair fed (fed a high‐fat diet, but in equal kcal as that eaten by the low‐fat fed animals to keep them lean). The Westernized high‐fat/high‐sugar and control groups were as follows: 1) 31.8% high‐fat, 25% sugar fed, 2) 10.6% low‐fat, 25% sugar fed, and 3) 31.8% high‐fat, 25% sugar pair fed group (fed a high‐fat high‐sugar diet, but in equal kcal as that eaten by the low‐fat high‐sugar fed animals to keep them lean). After 3 months, IESCs were isolated from each mouse using antibody‐based fluorescent cell sorting and grown in media containing inhibitors of differentiation. Crypt development was tracked for 14 days post‐plating and glucose‐induced crypt cell proliferation was measured on day 14. We found that crypts developed from IESCs isolated from high‐fat fed, obese mice formed a reduced number and size of budding structures compared with low‐fat fed, lean mice and high‐fat pair fed, lean mice, while the number of crypts developed per area measured were the same between the groups. Furthermore, glucose increased the proliferation of crypts developed from IESCs isolated from both low‐fat fed, lean mice and high‐fat pair fed, lean mice, but had no effect on the proliferation of crypts developed from IESCs isolated from high‐fat fed, obese mice. In contrast, the mice in the Westernized diet groups ate equal kcal amounts of each diet, were equal in body weight, and there were no significant differences in crypt cell proliferation between the groups. These results suggest that factors related to obesity and not the type of diet (high‐fat or high‐fat/high‐sugar) are driving lasting effects on IESC proliferation.Support or Funding InformationUSDA Hatch ILLU‐538‐926
Focal Adhesion Kinase forms Inhibitory Complexes with its Endogenous Inhibitor
Authors: Zak Taylor J , Robia Seth L , Samarel Allen M 
Published: November 2023

Focal adhesion kinase related non‐kinase (FRNK) is an inhibitor of focal adhesion kinase (FAK)‐dependent cell growth, survival, and migration pathways. In vascular smooth muscle cells, both FAK and FRNK are upregulated after vascular injury, suggesting balanced stimulation and inhibition of growth during recovery. Better understanding of the molecular mechanisms of FRNK inhibition of FAK are needed to understand vascular smooth muscle cell response to injury. Here we propose a novel mechanism by which FRNK can inhibit FAK: direct binding of FRNK to FAK forming an inhibitory complex within focal adhesions. This hypothesis is supported by co‐immunoprecipitation of FAK and FRNK. In addition, fluorescence resonance energy transfer (FRET) measurements suggest that FRNK binds directly to FAK within focal adhesions of live vascular smooth muscle cells. We hypothesized that this interaction might be regulated by serine phosphorylation of FRNK S217, a site we found to be basally highly phosphorylated at S217 by extracellular signal–regulated kinase 1/2 (ERK). To determine the significance of S217 phosphorylation, we generated a non‐phosphorylatable mutant FRNK by mutating serine 217 to alanine (S217A). S217A‐FRNK exhibited significantly higher amounts of FRET compared to wild type FRNK, suggesting increased interaction with FAK. Progressive acceptor photobleaching analysis revealed that the FRNK‐FAK complex consisted of FRNK and multiple FAK proteins in a high order hetero‐oligomer. The functional significance of the S217 phosphorylation site was suggested by S217A FRNK's more potent inhibition of FAK Y397 phosphorylation compared to wild type FRNK. FRNK S217A more potently decreased cell growth / survival compared to wild type. Specifically, S217A FRNK was a much more potent inducer of apoptosis in vascular smooth muscle cells compared to wild type FRNK, as determined by annexin staining and flow cytometry. We hypothesize that upregulation of FRNK after vascular injury results in the formation of a FRNK‐FAK inhibitory complex that serves to attenuate injury related growth and that phosphorylation of FRNK at S217 by ERK decreases the inhibitory FRNK‐FAK complex formation, allowing the cell to return to a normal resting state once healing has completed.Support or Funding InformationNIH: R01‐HL092321 and R01‐HL106189 to S.L.R., P01‐HL62426 to A.M.S., and F32‐HL096143 to Y.E.K.
Glucagon‐like peptide‐1 treatment stimulates Neurogenin3 expression and pancreatic beta‐cell neogenesis in adult mice
Authors: Dadheech Nidheesh , Buteau Jean 
Published: November 2023

Glucagon‐Like Peptide 1 (GLP‐1) is an intestinal hormone secreted after a meal. GLP‐1 is considered a key molecule in diabetes treatment because (a) it acts as a growth factor to promote beta‐cell mass expansion and (b) increases insulin secretion. Whereas GLP‐1 action on beta‐cell proliferation and survival has been extensively studied, its potential action on beta‐cell differentiation remains elusive. We herein performed lineage tracing experiments in genetically engineered mice to test the hypothesis that GLP‐1 stimulates the formation of new mature beta‐cells (neogenesis) in the adult pancreas.We used mice expressing a tamoxifen‐inducible Cre‐recombinase under the Neurog3 promoter to permanently label differentiating beta‐cells with a ZsGreen marker. This is because Neurog3 is transiently expressed in progenitor cells undergoing differentiation and is otherwise absent in the adult pancreas. Neurog3‐CreER/Rosa26‐LSL‐ZsGreen mice were injected with a moderate dose of streptozotocin to induce low levels of beta‐cell damage and regeneration. Then, mice were treated daily with tamoxifen alone or in combination with the long‐acting GLP‐1 analog Exendin4 (Ex‐4). Pancreata were harvested after 2 or 7 days of treatment.Control pancreata were devoid of ZsGreen staining, consistent with the fact that beta‐cell differentiation does not occur spontaneously in adult mice. Animals treated with Ex‐4, showed high frequency of ZsGreen+ cells in pancreatic islets and ducts, indicating that Ex‐4 induces Neurog3 expression in the adult pancreas. Mice treated with Ex‐4 for 2 days displayed small clusters of ZsGreen+ cells that were polyhormonal, a feature of immature/differentiating pancreatic endocrine cells. After 7 days of treatment, we detected a high number of insulin/ZsGreen dual positive cells, demonstrating that Ex‐4 stimulates the formation of new mature beta‐cells. We characterized the lineage of ZsGreen+ cells by studying the expression of various progenitor cell markers. Finally, we sorted ZsGreen+ cells to define their expression profile and confirm that newly‐differentiated beta‐cells could secrete insulin in response to physiological concentrations of glucose.Our study shows that GLP‐1, a naturally occurring hormone and an important anti‐diabetes therapeutic target, stimulates beta‐cell neogenesis. We thereby unveiled a new mode of action for the incretin hormone.