bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Continuous vs Interval Aerobic Exercise on Cognitive and Vascular Function of Juvenile Rats
Authors: DE MORAES CAMILA , Rebelo Macário Arosti , Garcia Nádia Fagundes , Padovan Cláudia Maria 
Published: April 2020

Physical exercise is well‐known as an effective approach to improve cardiovascular function as a response to the cardiac overload and arterial shear stress that occurs during physical effort. In recent years physical exercise has been show to be effective to improve cognitive function, particularly memory, in individuals with neurodegenerative diseases but less is known about this effect in health individuals. Furthermore, an emerging issue on exercise science is to determine the optimal dose of exercise in favor of these benefits. The aim was to evaluate the effects of continuous versus interval aerobic exercise training on spatial learning and spatial memory, anxiety‐like behavior and vascular reactivity of juvenile rats. Male Sprague Dawley rats (10‐week‐old) were divided into three groups: sedentary (SD), continuous training (C‐tr), and interval training (I‐tr). The continuous (running at 60% during 40 minutes) and interval training (3 x 2 min of running at 70% with 4 min running at 35%) were performed 3 times/wk during 6 weeks. Elevated plus maze test (EPM) was carried out on Monday of the sixth week and Barnes maze task was initiated on Friday of the same week. Contraction response of carotid rings was determined by tension increase, from baseline, using cumulative concentration‐response curve to phenylephrine (Phe 1nM‐100μM) in intact rings. Endothelial function was measured either by cumulative concentration‐response curve to acetylcholine (ACh 10nM‐100μM) or measuring endothelium‐dependent increase in tension to L‐NAME (100 μM) in rings contracted by Phe (2 μM). Exercise regimens did not influence spatial learning and memory as primary escape latency was not modified. Open arm exploration of EPM was 42% higher in C‐tr indicating lower anxiety‐like behavior. Regarding vascular function, Phe potency was lower in C‐tr and maximal response was higher in I‐tr. However, both trained groups had L‐NAME‐induced tension increased by half compared to SD group. Neither maximal response nor potency of ACh was modified. In conclusion, spatial learning and spatial memory were not affected by both exercise training protocols. However, C‐tr produced better outcomes regarding anxiety‐like symptoms. Endothelial function was improved in a similar way, and then I‐tr can be considered time‐effective. These results could be useful to support the selection of exercise training protocol in animal model. It is of particular importance as physical exercise parameters (training regimen, effort intensity and duration, weekly frequency) produces specific behavioral and physiological adaptation.Support or Funding InformationFAPESP Grant # 2017/27042‐6
Salt sensitive genotype is required for high fat diet associated hypertension and renal inflammation/injury in male Dahl rats
Authors: Xu Hui , Graver Hannah , Fernandes Roxanne , Jin Yining , Yarand Gloria , Harkema Jack R. , Rockwell Cheryl E. , Galligan James J. , Fink Gregory D. 
Published: April 2020

Elevated salt sensitivity and sympathetic activity are reported to contribute to obesity/high fat diet (HFD) associated hypertension and renal injury. We have reported that feeding male Dahl salt‐sensitive (SS) rats a HFD (with normal salt) robustly increases blood pressure and sympathetic support of blood pressure, and also causes severe renal inflammation/injury, when compared to male Dahl SS rats fed a standard rat diet (10% kcal from fat). However, it is hard to distinguish the effects of HFD per se on blood pressure and renal inflammation/injury in that setting, since Dahl SS rats fed a standard diet also develop moderate hypertension and mild renal inflammation/injury. To more clearly examine the effect of the SS genotype itself, in the current study we compared the impact of HFD on blood pressure and renal inflammation/injury in male SS (SS/JrHsd) and salt‐resistant (SR/JrHsd) rats (genetic control of SS rats) (Envigo). After 24 weeks on HFD diet feeding, starting at weaning (60% kcal from fat, 0.3% NaCl), SS rats developed severe hypertension (MAP 162±5mmHg, n=6) and renal inflammation/injury as expected. But SR rats on HFD had normal blood pressure (104±8mmHg, n=8) and renal histology. Compared with SS rats, SR rats showed much smaller mean arterial pressure (MAP) responses to acute ganglion blockade (hexamethonium, 30mg/kg, ip) (−14±5mmHg vs −37±5mmHg, P<0.05) and to chronic treatment with the angiotensin converting enzyme inhibitor enalapril (250mg/kg, 7 days in drinking water) (−21±7 mmHg vs −57±8 mmHg, P<0.05). SR rats showed less HFD associated metabolic disorders as they had lower body weight and plasma levels of cholesterol and triglycerides. SR rats also had much smaller spleen weights than SS rats. Immune cell analysis by flow‐cytometry showed that the splenic CD8+ population in SR rats was higher than that found in SS rats (16.4±0.7% vs 10.3±0.4%, P<0.05), whereas the CD4+ cell population was lower than that found in SS rats (18.3±0.6% vs 21.3±0.8%, P<0.05). The ratio of splenic CD4+/CD8+ was also significantly higher in SS rats than SR rats (2.10±0.08 vs 1.13±0.05, P<0.05). There were no strain differences in NK cells and B cells. Our study indicates that in male Dahl rats on HFD, the associated hypertension, metabolic disorders and renal inflammation/injury all require a salt sensitive genotype. Our study also confirms that the mechanisms responsible for HFD induced hypertension in male Dahl SS rats include increased neurogenic support of blood pressure and increased activity of the renin‐angiotensin system. Our study further suggests that a salt sensitive genotype impacts immune system responses to HFD. The mechanisms responsible for diet associated differences in immune cell regulation in the salt sensitive genetic background remain unknown.Support or Funding InformationNHLBI 2P01HL070687 for G.D.F, J.J.G. and H.X
The Effects of Cocaine on the Expression of Brain‐Derived Neurotrophic Factor in Female Rat Reward Circuits
Authors: Del Mar Nieves Torres Damaris , Ortíz Angela Silva , Silva Roberto Morales , Domínguez Ursula Gelpí , Rivera Angel Echevarría , Orengo Marian Sepúlveda 
Published: April 2020

Cocaine is a highly addictive psychostimulant drug with a high relapse rate. Studies have shown that women have greater subjective responses to cocaine depending on the hormonal phase they are in, making them more susceptible to addiction. Literature shows that sex hormones can modulate the activities of Brain‐Derived Neurotrophic Factor (BDNF). BDNF modulates the growth and survival of neurons in areas such as the nucleus accumbens (NAc) and prefrontal cortex, specifically the pre‐limbic cortex (PL). However, it is still unknown how hormonal stages influence the expression of BDNF in the different phases of cocaine addiction development: self‐administration, extinction and reinstatement. We hypothesized that the expression of BDNF in the NAc and PL varies depending on the hormonal stage, as well as the stage in the development of cocaine addiction. To determine this, female adult rats were subjected to 12 sessions of short‐access self‐administration of cocaine, 16 sessions of extinction and a session of cue‐primed reinstatement. Tissue from the PL and NAc were extracted to compare the expression of BDNF after each phase of cocaine addiction. Preliminary data suggests that BDNF decreases in the NAc during low‐hormonal phases (Diestrus and Metestrus), while it increases during high‐hormonal phases (Estrus and Proestrus). In addition, BDNF protein levels seem to be elevated in the prelimbic cortex after cue‐primed reinstatement, but further analysis is required to confirm this observation. These findings suggest that BDNF expression depends on the phase of cocaine addiction and the estrous cycle in female rats.Support or Funding InformationFunding was received from the following sources: UPR PRISE Program: #R25GM096955; Start up funds from Ponce Research Institute; Rise Program: NIH‐NIGMS #2R25GM082406; B.R.A.I.N. and M.A.G.I.C. Core: NIM‐HD MD007579.
Liquid‐Liquid Phase Separation by the Egr Transcriptional Coregulator NAB2
Authors: Correia Adele , Couto Rob , Spolidoro Sarina , King Gordo , Cunningham Michaela , Perez Adam , Adams Kenneth 
Published: April 2020

NGFI‐A‐binding proteins 1 and 2 (NAB1 and 2) are transcriptional coregulators with roles in a variety of cell types and behaviors. Their role in the peripheral nervous system is best established, where they are expressed in Schwann cells and essential for development and maintenance of peripheral nerve myelination. NAB1 and 2 have also been implicated in the regulation of hindbrain development, fibroblast activation in response to TGF‐β, neuronal and hematopoietic differentiation, and thymus cellularity. In addition, misregulation of NAB1 and 2 has been implicated in disease, including the peripheral neuropathy Charcot‐Marie‐Tooth disease and cancers that develop in the form of solitary fibrous tumors. NAB1/2 mediate their effects through interactions with the Egr family of transcription factors, which they bind via their amino terminal NCD1 (NAB‐conserved domain 1). Upon binding Egr, they either repress or potentiate gene expression is a gene‐specific manner. Two NAB domains have been shown to possess transcriptional repression activity, an internal NCD2 domain and a carboxy terminal CID (CHD4‐interacting domain). However, a NAB domain responsible for transcriptional potentiation has not been determined, nor have molecular mechanisms responsible for regulating NAB1/2 activity. Here we provide evidence that NAB2 possesses the ability to undergo liquid‐liquid phase separation (LLPS) to form liquid droplets in cells, which has recently been characterized as critical event through which some transcriptional activators mediate their effects on gene expression. Transfection of multiple cell lines with a NAB2‐GFP fusion resulted in the formation of several puncta within the nucleus that exhibit fluorescence recovery after photo‐bleaching (FRAP). Assembly into puncta is prevented by either truncation of the NAB2 NCD1 domain or by alanine substitution of two arginine residues within that region (Arg‐97 and Arg‐98), indicating that NAB2 droplet formation is dependent on the amino acid composition within NCD1. Examination of the NAB2 amino acid sequence using PONDR predicted 62.5% disordered sequence and 37.5% ordered sequence. Ongoing experiments are evaluating the necessity of additional regions within NAB2 for LLPS as well as whether NAB2 LLPS is affected by phosphorylation as several sites. These data may provide insight into the mechanisms through which NAB2 is regulated and/or mediates its effects on gene expression.Support or Funding InformationBridgewater State University Undergraduate Research Program
ERK‐mediated Phosphorylation of the Egr Transcriptional Coregulator NAB2 at Multiple Sites
Authors: King Gordo , Perez Adam , Spolidoro Sarina , Cunningham Michaela , Corriea Adele , Couto Rob , Adams Kenneth 
Published: April 2020

The early growth response (Egr) family of transcription factors comprises five members, Egr1‐4 and Wilms Tumor 1 (WT1), which play roles in various cell behaviors including proliferation, apoptosis, and differentiation in a cell type‐ and stimulus‐specific manner. Roles for Egr1‐3 are particularly well‐documented in the nervous system. Egr1 and 3 contribute to learning and memory through regulation of genes that mediate synaptic plasticity and long‐term potentiation. Egr2 controls hindbrain development through regulation of Hox gene expression and drives peripheral nerve myelination through, at least in part, activation of the gene encoding myelin protein zero in Schwann cells. Egr1 and 2 also contribute to transcriptional network that drives neuronal differentiation of PC12 cells. However, the mechanisms that regulate Egr1‐3 activities in the nervous system are not fully understood. One mechanism of regulation involves protein‐protein interactions with co‐regulators NAB1 and 2 through a conserved R1 domain in Egr1‐3. Most reports demonstrate that NABs repress Egr1‐3 transactivation activity when bound, however, NABs can also enhance transactivation in a target gene‐specific manner. The mechanisms controlling the effect of NABs on Egr activities are not clear. Here, we provide evidence that NAB2 regulation may involve its phosphorylation at several sites by ERK. Using PC12 cells as a model system, our data demonstrate that nerve growth factor (NGF) induces a NAB2 mobility shift in SDS‐PAGE within 10 minutes of treatment. The mobility shift was reversed when lysates from NGF‐treated cells were treated with lambda phosphatase, suggesting the shift is due to phosphorylation. Inhibition of ERK signaling during NGF treatment blocked the mobility shift, while recombinant ERK phosphorylated recombinant NAB2 in an in vitro kinase assay, together indicating that direct phosphorylation of NAB2 by ERK may be responsible for the NAB2 mobility shift in response to NGF. Nine potential ERK phosphorylation sites were identified in NAB2, which were mutated individually to alanine within a NAB2 expression construct to evaluate phosphorylation at those sites based on their mobility in SDS‐PAGE. Of the nine mutants, three exhibited clear changes in NAB2 mobility, which were additive in double and triple mutants for those sites. Ongoing experiments are evaluating the effect of NAB2 phosphorylation on its localization and regulation of Egr1‐3.Support or Funding InformationBridgewater State University Undergraduate Research Program
The Effect of Primary Cilia Restoration on Cancer Cells
Authors: Jamal Maha H. , Nauli Surya M. 
Published: April 2020

Primary cilia are sensory organelles that exist on the surface of most cells. Since primary cilia play an important role in cell cycle and cilia‐related signaling pathways (e.g. Hedghog and Wnt signaling pathways), cilia have been proposed to be involved in cancer development. In our current study, we characterized the expression of the primary cilia in two prostate cancer (PC3 and DU145), and one lung cancer (NL20‐TA) cell lines by examining cilia formation and measuring cilia length. Moreover, we investigated the correlation between primary cilia and cilia‐related signaling pathways. We found that the frequency and the length of the primary cilia were reduced in PC3 prostate cancer. Primary cilia were absent in DU‐145 prostate cancer and NL20‐TA lung cancer. Furthermore, the β‐catenin of Wnt signaling pathway was elevated in the prostate and lung cancers, suggesting an association between primary cilia and Wnt signaling in cancer cells. We also assessed the ability of rapamycin to restore primary cilium expression in cancer cells. We found that treatment with rapamycin for 8 days increased the percentage of ciliated cells in PC3 prostate cancer and restored primary cilium formation in DU145 prostate cancer and NL20‐TA lung cancer. We next investigated the correlation between primary cilia and Wnt signaling pathways after restoring primary cilia expression in cancer cells. We found that treatment with rapamycin for 8 days reduced the level of β‐catenin in prostate cancer cells. In summary, our data show a potential role of primary cilia in cell proliferation.Support or Funding InformationSACM
Radiotelemetry and Diffusion Tensor Imaging Revealed that Baroreflex Exhibits Disproportional and Paradoxical Changes During Isoflurane Anesthesia
Authors: Chan Samuel H.H. 
Published: April 2020

Using isoflurane as the representative anesthetic agent, the aim of this study was to address the issue of whether general anesthetics induce their depressive actions equally on all aspects of cardiovascular functions and their regulations and whether the degree of depression is directly related to the doses. To mimic the clinical setting during surgery, C57BL/6 mice were instrumented to record by radiotelemetry changes in blood pressure (BP), heart rate (HR) and both arms of the baroreflex from a conscious state to incremental concentrations of isoflurane. We found that there was a significant but disproportional reduction in the cardiovascular parameters when mice were subjected to 1.5% isoflurane anesthesia. Compared with the conscious state, the averaged reduction in BP or HR amounted to 23.5% or 20.5%. On the other hand, the experimental indices for baroreflex‐mediated sympathetic vasomotor tone and cardiac vagal baroreflex manifested a precipitous decline of 90.0% and 63.4%. Paradoxically, on incremental concentrations of isoflurane up to a maximum of 4%, mice exhibited sustained BP and HR, alongside returning of both arms of the baroreflex towards the conscious level. These results were corroborated by diffusion tensor imaging of the medulla oblongata. Tractographic analysis of the baroreflex neural circuits showed a decrease in fraction anisotropy indicative of reduced magnitude of functional connectivity between the nucleus tractus solitarii and rostral ventrolateral medulla or nucleus ambiguus accompanied the augmented baroreflex‐mediate sympathetic vasomotor tone or cardiac vagal baroreflex in response to increased concentrations of isoflurane. We further found that bilateral adrenalectomy exerted minimal effects on the changes in BP, HR and baroreflex in mice subjected to incremental concentrations of isoflurane. It is therefore unlikely that norepinephrine and epinephrine released from the adrenal medulla may account for the disproportional and paradoxical changes in BP, HR and baroreflex under isoflurane anesthesia. These surprise observations offer at least two challenges to the general assumptions on general anesthesia. The effects of isoflurane on cardiovascular functions and their regulations are not exerted proportionally, and both baroreflex‐mediated sympathetic vasomotor tone and cardiac vagal baroreflex exhibit large functional capacity and plasticity in terms of regulating BP and HR.Support or Funding InformationSupported in part by the Ministry of Science and Technology, Taiwan (MOST‐107‐2320‐B‐182A‐024 and MOST‐108‐2320‐B‐182A‐007).
2,3‐Dichlorophenylpiperazine (DCPP)‐derived Antipsychotics Obstruct Cholesterol Biosynthesis in hiPSC‐derived Neural Precursors and Early Postmitotic Neurons
Authors: Kim John , Neely M. Diana , Kim Hye-Young , Tallman Keri , Porter Ned 
Published: April 2020

Antipsychotic prescriptions have steadily expanded in recent years as have their uses for “off‐label” indications such as bipolar affective disorder and major depressive disorder. Aripiprazole (Abilify) and cariprazine (Vraylar) are atypical antipsychotics which share a 2,3‐dichlorophenylpiperazine (2,3‐DCPP) moiety in their chemical structure. Preclinical and clinical studies have shown these small molecules have off‐target inhibitory effects on 7‐dehydrocholesterol reductase (DHCR7) which converts the highly oxidizable lipid 7‐dehydrocholesterol (7‐DHC) to cholesterol. Recent studies have also demonstrated that 2,3‐DCPP alone can potently inhibit DHCR7. The grave consequences of impaired DHCR7 function are demonstrated in Smith‐Lemli‐Opitz syndrome (SLOS), a rare neurodevelopmental disorder in which genetic defects in the enzyme result in the abnormal accumulation of 7‐DHC. Given the developmental deficits seen in SLOS, the use of DHCR7 inhibitors during the first trimester of pregnancy has been suggested to have deleterious outcomes in fetal development. Recognizing the dynamic nature of cellular biochemistry in neural development, we examined the impact of two structurally similar antipsychotics on cholesterol biosynthesis precursor profiles in highly proliferative NPCs and early post‐mitotic neurons differentiated from human‐induced pluripotent stem cells (hiPSCs). We exposed cortical glutamatergic and mesencephalic dopaminergic NPCs and early postmitotic neurons to increasing concentrations (1–1000 nM) of aripiprazole and cariprazine for 48 hours after which we quantified lipid extracts via liquid chromatography‐tandem mass spectrometry (LC‐MS‐MS). Cortical glutamatergic and mesencephalic dopaminergic lineages of both developmental stages exhibited dose‐dependent increases in DHCR7 substrates and corresponding decreases in DHCR7 products. While in early postmitotic neurons both compounds showed similar potency with observable changes in sterol profile at >10 nM exposures, proliferative NPCs demonstrated a particularly high sensitivity to cariprazine with significant effects at 1 nM. These findings are highly significant as patients on cariprazine retain plasma levels of cariprazine and its metabolites above 100 nM for many months. Despite the substantial alterations in sterol profile, no significant cytotoxicity was observed at any dosage. Overall, these observations illustrate the importance of assaying DHCR7 activity as it relates to teratogenicity of novel pharmaceuticals, especially those bearing the 2,3‐DCPP structural unit.Support or Funding InformationThis work was supported by the SyBBURE Searle Program and NIH R01HD064727‐01 (NAP). Cell counts were obtained via the ImageXPress instrument of the Vanderbilt High Throughput Screening (HTS) facility.