bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Strength Training and Green Tea on Memory Impairments Associated with &[Beta]‐Amyloid Peptide
Authors: Carpes Felipe P. , Schimidt Helen Lidiane , Carrazoni Guilherme , Garcia Alexandre , Izquierdo Iván , Mello-Carpes Pâmela Billig 
Published: April 2020

Antioxidant supplementation and physical exercise have been discussed as strategies to minimize neurodegeneration in Alzheimer’s disease (AD). We investigated the neuroprotective effects of strength exercise (StrEx) and green tea (GT) supplementation either combined or isolated on memory impairments induced by a β‐amyloid characterizing an AD‐like condition. Wistar male rats were submitted to 8 weeks of StrEx or GT supplementation or its combination. AD was induced by injection of Aβ (25–35) in the hippocampus. We evaluate object recognition (OR) and social recognition (SR) memory, and then hippocampus was removed for biochemical analysis. StrEx improved OR and SR memory. StrEx combined with GT improved OR memory and did not improve SR memory. GT alone decreased antioxidant capacity and improved acetylcholinesterase activity. Both strength exercise or green tea are effective against cognitive impairments resultant of β‐amyloid but benefits do not add up when the two interventions are associated.Support or Funding InformationNational Council for Scientific and Technological Development of Brazil
Beyond academic learning: how can human cadaver dissection promote medical students’ professional identity development?
Authors: Eckert Tabitha , Topping Daniel , Abrams Matthew , Daly Katherine 
Published: April 2020

INTRODUCTIONGrowing evidence supports the potential activities such as memorial services and reflective writing centered around the human cadaver dissection (HCD) experience to support elements of medical student wellness. These activities promote psychological and professional development, increase resilience, protect against burnout and foster a sense of connection and community. This study is a qualitative analysis of a reflective writing exercise utilizing grounded theory to answer the question: “What is the impact of the first‐year HCD on medical students’ personal and professional development?”METHODSThis qualitative cross‐sectional study was conducted at a medical school in the Southeastern United States. The study population consisted of 117 first year medical (M1) students, 70 males and 47 females, concluding their HCD module. A narrative reflection tool consisting of four reflection questions was designed to address the emotional elements of students’ HCD and promote introspection. The questionnaire was provided to twenty groups of 5–6 first‐year students. Grounded theory analysis was used to explore themes that arose in the students’ responses.RESULTSParticipants exhibited several common initial reactions to HCD. Reflections commonly included themes of gratitude, awareness of one’s own mortality, appreciation for health and lifestyle, and recognition of the benefits of tangibly learning intricate anatomical details. After analysis of all team responses, a total of 266 unique open codes were identified for all four interview questions. These open codes were sorted into ten distinct broader axial codes, some of which had 2–3 sub‐themes.CONCLUSIONOur study’s timely findings may inform anatomy program stakeholders as they face increasing pressure to decrease or eliminate HCD as part of curricular reform. HCD offers medical students holistic growth opportunities that are less impactful when encountered through alternative technologies. Institutions utilizing HCD should maximize this high‐yield, easy‐to‐implement opportunity to foster medical students’ professional identity development.
Primary Themes and Subthemes

Theme

Subtheme

1. Gratitude

No subthemes

2. Patient’s Story

No subthemes

3. Learning Anatomy

3.1 Lessons from my Donor
3.2 Tangible/Tactile Learning
3.3 Disease Process
3.4 Visual Learning

4. Diagnosis

4.1 Critical Thinking about Dx
4.2 Diligence
4.3 Creativity

5. Humanity’ and Compassion

No subthemes

6. Reflection

No subthemes

7. Career Development as a Physician

No subthemes

8. Lifestyle and Prevention

8.1 Body Appreciation
8.2 Preventing Disease

9. Empathy

No subthemes

10. Mortality

No subthemes
The Reflex Sympathetic Activation Attenuates Systemic Inflammation in Unanesthetized Rats
Authors: Brognara-Dias Fernanda , Castania Jaci Airton , Dias Daniel Penteado Martins , Kanashiro Alexandre , Salgado Helio Cesar 
Published: April 2020

The literature reports that electrical activation or surgical denervation of the sympathetic nerves elicits anti‐inflammatory effects. Our previous study (American Heart Association’s Council on Hypertension 2016 Scientific Sessions: AP305) also indicated that sympathetic activation, by bilateral carotid occlusion (BCO) in unanesthetized rats, attenuates the release of pro‐inflammatory cytokines in an experimental model of sepsis. However, to expand the knowledge about the anti‐inflammatory potential of this arm of the autonomic nervous system, the objective of the present study was to investigate the role of global reflex sympathetic activation by BCO in a systemic inflammation induced by a low dose of lipopolysaccharide (LPS). For this, femoral artery and vein catheters were inserted into anesthetized Wistar Hannover male rats, for arterial pressure recording and LPS administration, respectively. Moreover, the subjects were implanted with pneumatic cuffs around the common carotid arteries for performing the BCO. On the next day, under unanesthetized rats, the arterial pressure was recorded continuously during 7 hours, including the baseline period. After baseline parameters recording, the BCO was performed for 20 s; and immediately after, LPS (60 μg/kg, i.v.) or saline was administrated. Blood samples were collected under different moments (90, 180, 270 and 360 min), after LPS or saline injection, for analyzing plasma cytokines (TNF, IL‐6, IL‐1β, and IL‐10) levels over time. As expected, BCO was effective to increase the arterial pressure, confirming the reflex sympathetic activation. Over time, no difference was observed among all groups concerning the arterial pressure; however, the groups which received LPS showed an increase in heart rate at 180, 270 and 360 min, compared with the saline group. However, the BCO did not change this response. Concerning the plasma cytokine levels, 90 min after LPS, BCO attenuated TNF and IL‐1β levels, as compared to LPS treated rats [TNF: 1831 ± 290 (n = 8) vs. 1326 ± 180 pg/mL (n = 8); IL‐1β: 212 ± 74 (n = 8) vs. 104 ± 39 pg/mL, (n = 8)]. BCO also increased the IL‐10 levels at 90 min [410 ± 55 (n = 8) vs. 730 ± 66 pg/mL (n = 8)]. Nevertheless, BCO did not change IL‐6 levels [IL‐6: 8389 ± 1480 (n = 8) vs. 8546 ± 1560 pg/mL (n = 8)]. No differences in plasma cytokine levels were observed at 180, 270 or 360 min after LPS, comparing the LPS group with the LPS+BCO group. In conclusion, these results suggest that the reflex sympathetic activation, in unanesthetized rats, attenuates plasma pro‐inflammatory cytokines and increase the anti‐inflammatory cytokine release in a model of systemic inflammation. These data provide support to previous evidence concerning the anti‐inflammatory effects of the sympathetic arm of the autonomic nervous system.Support or Funding InformationFAPESP (2017/05163‐6; 2013/20549‐7) and CNPq (402076/2016‐8).
The Effect of Zinc on the Marker Expression in Cell Transitional Activities
Authors: Hu Yuli , Li Yang V. 
Published: April 2020

Zinc is a trace element that participates in protein structure, enzyme activity, and gene regulation. Zinc homeostasis helps to maintain strong immunity, bone health, and the levels of various hormones, and it is also involved in the regulation of oxidative stress, cell death, and aging processes. We are interested in studying the effect of zinc homeostasis on the marker expression in cell transitional activities, including markers for epithelial‐to‐mesenchymal transition (EMT) and stem cells. In my preliminary experiments, the dissociation of zinc from its binding sites has been achieved by acidic treatment because the binding between zinc and protein is tight at basic pH and loose at acidic pH. We hypothesize that the acid‐induced dissociation of zinc from its binding sites contributes to the cell transitional activities, from one type of cell to a different kind of cells during EMT and stem cell development. In my preliminary results, acid treatment resulted in the accumulation of spindle‐shaped cells, similar to the morphology of EMT cells suggested by the literature. It increased the expression of vimentin (a marker labeling EMT), CDK2 (a marker labeling G1 and S phases), and SSEA‐4 (a marker labeling stem cells). This acidic treatment also decreased the doubling time of mouse gastric cells during long‐term cell culture, suggesting that the acid‐induced zinc dissociation promoted cellular growth perhaps through the activation of EMT, the facilitation of cell cycle, or the development of stem cells. Moreover, the chelation of zinc alleviated the spindle cell accumulation, vimentin expression, and SSEA‐4 expression induced by the acid exposure, confirming the importance of zinc dissociation from its binding sites in the cell transitional activities. In conclusion, zinc functions in cell transitional activities through regulating the expression levels of marker proteins involved in EMT, cell cycle, and stem cell development.Support or Funding InformationFunding is provided partially by NIH (# NS081629) to YVL. Thanks to the Osteopathic Heritage Foundations, Graduate Assistantship Program at Ohio University Heritage College of Osteopathic Medicine for supporting graduate student YH.
A novel series of nitrofuran derivatives produces an anti‐tumor effect via a p53‐dependent mechanism
Authors: Al Koussa Houssam Khaled , Abrahamian Carla F. , Elzahhar Perihan M. , Serie Marwa Abu , Belal Ahmed , El-Yazbi Ahmed F. 
Published: April 2020

Nitrofurantoin (NF) is an antibacterial that acts by inducing DNA damage. Increased selectivity towards bacterial DNA is conferred through the rapid activation by prokaryotic reductases. In cancer therapy, radiation and anti‐neoplastic drugs induce DNA damage to activate the p53‐dependent pathway, provoking apoptosis in cancer cells. In this study, a novel series of nitrofuran derivatives was designed with a presumed enhanced eukaryotic activity. The safety and the anti‐tumor efficacy of this series was assessed. Anticancer effects were assessed on colorectal cancer (Caco‐2), breast cancer (MCF‐7), cervical cancer (Hela), and liver cancer cells (HepG‐2). Cytotoxicity was estimated by MTT assays. Three compounds, NF‐5, NPO, and NS‐1 were shown to have the highest cytotoxic activity against cancer cells at IC50 values that are several‐fold lower that those observed for non‐malignant lung fibroblasts. The abilities to induce oxidative stress and apoptosis were tested by flow cytometry to measure dihydrodichlorofluorescein fluorescence and nuclear annexin‐V staining, and compared to that of NF and the reference chemotherapeutic drug (5‐FU). Other apoptosis markers measured include caspase3/7 activity and Bax/Bcl2 ratio. NF‐5, NPO, and NS‐1 induced oxidative DNA damage in cancer cells in vitro with subsequent cellular apoptosis. Furthermore, the three derivatives induced more than 50% increase in reactive oxygen species when compared to 5‐FU. Cells treated with these drugs showed an increased Bax/Bcl2 ratio and caspase 3/7 activity compared to the traditional chemotherapeutic drug. A positive linear correlation was shown between the oxidative load produced in the cells and the increase in apoptotic markers. Interestingly, despite equivalent induction of DNA damage demonstrated by similar pATM nuclear shuttling, NF‐5, NPO, and NS‐1 produced more cytotoxicity in MCF‐7 cells compared to the p53 mutant breast cancer cell line MDA‐MB‐231. Moreover, the effect of these derivatives on the p53 interaction with its negative modulator Murine Double Minute 2 (MDM2) was assessed using a multi‐spot sandwich ELISA kit. NF‐5, NPO, and NS‐1 promoted p53 release from MDM2 at concentrations that are 2–3 orders of magnitude lower than their cytotoxic IC50 values. These findings were further confirmed by in silico docking studies demonstrating possible binding sites on the protein. Further experiments are underway to assess the ability of lower, non‐cytotoxic concentrations of these drugs to improve the radio‐sensitivity of cancer cells via activation of p53‐dependnet pathways.Support or Funding InformationFunded by: AUB‐FM MPP grant #320148
Defining the role of microglia in breast‐to‐brain metastasis
Authors: Thompson Kaitlyn Koenig , Tsirka Stella E. 
Published: April 2020

A diagnosis of brain metastasis is devastating to cancer patients, with survival measured in only months. Due to prolonged life expectancy of cancer patients, the frequency of brain metastasis is increasing, with the highest incidences occurring when the primary site is the lung, breast, and melanoma. Treatment of brain metastatic lesions is challenging; differences in the brain microenvironment and the encompassing blood‐brain barrier are two major obstacles to successful systemic therapy. A unique player in the brain tumor microenvironment (TME) are microglia, the resident innate immune cells of the central nervous system. How microglia influence metastatic tumor progression in the brain, and their therapeutic potential in this setting remain to be elucidated. To first characterize the role of microglia in a model of breast‐to‐brain metastasis, we deplete them using the orally available colony stimulating factor 1 receptor (CSF1R) inhibitor, PLX5622, which readily crosses the blood‐brain barrier. Brain metastatic development of a C57BL/6 syngeneic breast cancer line is monitored, and the resulting TME characterized histologically. Further, we utilize in vitro assays to investigate direct communication between microglia and neoplastic cells, measuring tumor cell migration and invasion, and microglial polarization. We also employ PLX5622 therapeutically, after the development of brain metastasis to understand whether dynamic elimination of microglia may be a viable therapy. Understanding microglia’s role in the development of metastatic disease and how these cells may be targeted therapeutically is critical to improving the treatment of brain metastasis.Support or Funding InformationThis work is supported by NIH IRACDA K12GM102779.
Optimizing a biosensor‐based assay for ubiquitination activation
Authors: Broadberry Roma Lucette , Berndsen Christopher 
Published: April 2020

Ubiquitination is a post‐translational modification which regulates protein degradation, DNA damage signaling, and inflammatory response. Three transfer enzymes catalyze the reaction’s pathway: E1 activating enzyme, E2 conjugating enzyme, and E3 ligating enzyme, respectively. Despite the identification of these enzymes’ structure and function, a complete understanding of their catalytic mechanisms remains unclear. Clarification of the ubiquitination mechanism could serve medicinal strategies due ubiquitin’s (Ub’s) involvement with target protein degradation. Existing assays for ubiquitination are either too imprecise, expensive, or radioactive for common usage, thus we are trying to develop a cheap, continuous assay which can make ubiquitination research more accessible. Our approach depends on the detection of ATP as E1 cleaves ATP into pyrophosphate (PPi) and AMP for Ub‐activation. Previous fluorescent assay designs for Ub‐E1 activation were attempted and examined including a terbium‐norfloxacin assay and a chloroacetaldehyde assay, but each showed limitations. The terbium‐norfloxacin assay detected ATP fluorescence, but interfered with the protein pathway, while the chloroacetaldehyde assay used organic sensors to modify ATP, but with little success. We have since turned to adapting a genetically‐encoded nucleotide biosensor, Perceval, toward measuring ATP hydrolysis of E1 in the ubiquitination pathway. Developed in the Yellen Lab at Harvard Medical School, Perceval was designed to report real‐time changes in cellular energy as a result of its competitive binding of ATP and ADP. We have worked to tailor the Perceval model towards measuring solely the ATP hydrolysis of ubiquitination in vitro, starting with E1 activation. After optimizing Perceval’s purification, we showed Perceval has a high affinity for ATP without the ADP competitive binding aspect, and ensured AMP and PPi do not interfere with the biosensor. We similarly tested solutions containing different Ub protein substrates and E1s, and found that Perceval’s affinity for ATP is not interrupted by critical components of the ubiquitination pathway. When directly applied to ubiquitination, fluorescence readings were taken at single‐time points in the ubiquitination pathway and over a continuous duration. Preliminary data suggest Perceval could be a potential biosensor for measuring Ub activation in real time. Future directions will look to further optimize assay conditions as well as test other biosensors for comparison.Support or Funding InformationJames Madison University Department of Chemistry and Biochemistry, NSF REU CHE‐1757874, Thomas and Kate Jeffress Memorial Trust, 4‐VA Organization
Inhibition of Sirtuin‐1 Ameliorates Vascular Remodeling and Hypertension in SHR
Authors: Arifen Nahida , Li Yuan , Srivastava Ashok K. , Anand-Srivastava Madhu 
Published: April 2020

Sirtuin‐1 (SIRT1), class III histone deacetylase, has been shown to be overexpressed in hearts from spontaneously hypertensive rats (SHR). We recently showed that vascular smooth muscle cells (VSMC) from SHR exhibit enhanced expression of SIRT1 as compared to age‐matched Wister Kyoto (WKY) rats and contribute to the upregulation of Giα proteins implicated in the pathogenesis of hypertension. The present study was undertaken to investigate the role of upregulated SIRT1 expression in the pathogenesis of hypertension and associated vascular remodeling in SHR and to explore the underlying molecular mechanisms involved in this response. For this study, a selective inhibitor of SIRT1, EX‐527 (5mg/kg of body weight) was injected intraperitoneally into 8‐week‐old adult SHR and age‐matched WKY rats twice per week for 3 weeks. The blood pressure (BP) and heart rate was measured twice a week by the CODA™ non‐invasive tail cuff method. Treatment of SHR with Ex‐527 attenuated high BP by 50 mmHg and inhibited the augmented heart rate. The overexpression of Giα proteins in heart, VSMCs and aorta was also attenuated to the control levels by EX‐527. In addition, inhibition of SIRT1 also attenuated the enhanced levels of superoxide anion, NADPH oxidase activity, enhanced phosphorylation of c‐Src and ERK1/2/AKT in VSMCs isolated from EX‐527 treated SHR. Furthermore, the decreased expression of endothelial nitric oxide synthase (eNOS) in VSMCs and aorta from SHR was also restored to control levels by EX‐527. The hyperproliferation and hypertrophy exhibited by VSMC from SHR, the enhanced expression of cell cycle proteins cyclin D1 and cdk4 and Gqα /PLCβ1 proteins were also attenuated by EX‐527 treatment. These results suggest that the overexpression of SIRT1 contributes to the development of high BP and vascular remodeling in SHR and its inhibition improves hypertension and vascular remodeling. It may thus be suggested that inhibitors of SIRT1 may have the potential to be used as therapeutic agents in the treatment of cardiovascular complications associated with hypertension.Support or Funding InformationSupported by grant from Canadian Institutes of Health Research (CIHR)
TGF‐β Signaling Regulates SLC8A3 Expression and Oxidative Stress in Mouse Developing Dopaminergic Neurons
Authors: Chleilat Enaam , Krieglstein Kerstin , Roussa Eleni 
Published: April 2020

Calcium homeostasis is a cellular process required for proper cell function and survival, and maintained by the coordinated action of several transporters, among them members of the NCX family, such as SLC8A3, the isoform 3 of the Na+/Ca2+ exchanger (NCX3). Transforming growth factor beta (TGF‐β) signaling belongs to signaling cascades defining development and survival of several neuronal groups and known to regulate several channels and transporters. We have generated a conditional knockout mouse with cell‐type specific deletion of TGF‐β signalling from Engrailed 1 (En1) expressing cells, i.e. in cells derived from rhombomere r1. Subsequently, we have investigated regulation of SLC8A3, and elucidated the underlying molecular mechanisms. The results show that SLC8A3 expression is significantly downregulated in developing dopaminergic and serotonergic neurons from mutant mice and that low SLC8A3 abundance prevents the expression of the anti‐apoptotic Bcl‐xL. We also show that TGF‐β signaling regulates SLC8A3 expression via the canonical (Smad‐dependent) and MAPK signaling pathways and chromatin immunoprecipitation has revealed that TGF‐β signaling directly regulates transcription of Slc8a3 through binding of Smad4 to the Slc8a3 promoter. Moreover, expression of the lipid peroxidation markers malondialdehyde (MDA) and 4‐hydroxynonenal (4HNE) was upregulated in dopaminergic neurons lacking TGF‐β signaling. These results suggest that TGF‐β signaling regulates SLC8A3 expression in developing dopaminergic and serotonergic neurons thereby preventing oxidative stress.Support or Funding InformationDeutsche Forschungsgemeinschaft (DFG) [Kr1477/10‐3]
Raf promotes dimerization of the Ras G‐domain
Authors: Packer Morgan Renee , Parker Jillian A. , Chung Jean K. , Li Zhen-lu , Lee Young Kwang , Guterres Hugo , Cookis Trinity , Hossain Amin , Donnelly Daniel P. , Agar Jeffrey N. , Makowski Lee , Buck Matthias , Groves Jay T. , Mattos Carla 
Published: April 2020

The Ras/Raf/MEK/ERK pathway is a major regulator of cell proliferation and is highly implicated in human cancers. Ras dimerization was first proposed thirty years ago, and it is known that Ras dimerization is essential for Raf activation, yet the mechanism through which this occurs has remained elusive. Attempts to detect Ras dimers on supported membranes have led to the conclusion that Ras does not dimerize in the absence of other factors. Here we show that the Ras binding domain of Raf (Raf‐RBD) is the key element prompting Ras dimerization. A small amount of Ras/Raf‐RBD dimer is seen in solution, while the addition of Raf‐RBD to Ras on supported lipid membranes produces robust levels of dimers. On the membrane, Ras/Raf‐RBD binding and Ras dimerization appear to be concerted events that lead to a high‐affinity signaling complex. Molecular dynamics simulations of Ras and Raf‐RBD alone, in a complex, and in the dimer reveal that the proteins become increasingly connected with higher levels of allosteric networks. This is apparent in the increasing connectivity between the helices involved in dimerization, helices 4 and 5, developing more consistent communication with the phosphate binding loop in the Ras active site. These data reveal a novel mode of regulation of the mitogenic Ras/Raf/MEK/ERK pathway.Support or Funding InformationNSF‐MCB‐1517295