bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relationship between ER Stress and Protein Quality Control at the Translocon
Authors: Broshar Courtney Leigh , Buchanan Bryce , Mehrtash Adrian , Runnebohm Avery , Snow Brian , Scanameo Laura , Hochstrasser Mark , Rubenstein Eric 
Published: April 2020

Multiple diseases are associated with elevated levels of endoplasmic reticulum (ER) stress, including some forms of cancer, neurodegeneration, and heart disease. ER stress arises when ER‐resident proteins misfold and accumulate. Cells respond by activating multiple mechanisms which reduce ER stress. Our objective is to understand the relationship between ER stress and protein quality control at the endoplasmic reticulum, using Saccharomyces cerevisiae as a model organism. The ubiquitin‐proteasome system (UPS) is responsible for the majority of degradation of misfolded and aberrant proteins at the ER (such as those arising during ER stress) through ER‐associated protein degradation (ERAD). We have found ER stress differentially impairs ERAD pathways, including those mediated by the same ubiquitin ligase. For example, ER stress impairs degradation of translocon‐associated proteins and of proteins with luminal degradation signals (ERAD‐T and ERAD‐L substrates, respectively). Degradation of these substrates is mediated by the Hrd1 ubiquitin ligase. In contrast, degradation of proteins with intramembrane degradation signals (ERAD‐M substrates), which also requires Hrd1, was not impaired by ER stress. We compared the effects of ER stress caused by protein misfolding and of ER stress caused by disruption of lipid homeostasis on the degradation of ERAD‐T substrates. We observed that ER stress caused by protein misfolding impaired ERAD‐T. On the contrary, ERAD‐T was unaffected by ER stress caused by disruption of lipid homeostasis. We then investigated the effects of different forms of stress on ERAD‐T. We observed that oxidative stress and heat shock did not impair ERAD‐T. We found that none of four characterized ER stress‐sensing mechanisms were required for ERAD‐T or its impairment by ER stress. Taken together, our results indicate that ER stress differentially impairs ER protein quality control mechanisms and suggest the existence of a novel ER stress‐responsive mechanism that impairs ERAD‐T. Understanding how the cell responds to ER stress may inform the treatment of diseases associated with stress.Support or Funding InformationThis work was supported by Ball State University ASPiRE research awards to BWB, CLB, and AMR; a Ball State University Department of Biology Sigma Zeta research award to BJS, an NIH grant to MH (GM046904), a Ball State University Faculty Advance research award to EMR, an Indiana Academy of Science Senior Research Grant to EMR, and an NIH grant to EMR (GM111713).
Functional cooperativity between the trigger factor chaperone and the ClpXP proteolytic complex
Authors: Houry Walid A. 
Published: April 2020

A functional association was uncovered between the ribosome‐associated trigger factor (TF) chaperone and the ClpXP degradation complex in bacteria. Bioinformatic analyses demonstrated conservation of the close proximity of tig, gene coding for TF, and genes coding for ClpXP suggesting a functional association. Effect of TF on ClpXP‐dependent degradation varied based on the nature of substrate. While degradation of some substrates was slowed down or unaffected by TF, surprisingly, TF increased the degradation rate for a third class of substrates. These include λ phage replication protein λO, master regulator of stationary phase RpoS, and SsrA‐tagged proteins. Globally, TF enhances the degradation of about 2% of newly synthesized proteins. TF was found to interact through multiple sites with ClpX in a highly dynamic fashion to promote protein degradation. This chaperone‐protease cooperation constitutes a unique and likely ancestral aspect of cellular protein homeostasis in which TF acts as an adaptor for ClpXP.Support or Funding InformationCanadian Institutes of Health Research
Association of DRD2 Gene Ser311Cys Polymorphisms, DAT 40bp VNTR and Cannabis Dependence
Authors: Olasore Holiness Adedeji , Osuntoki Akinniyi Adediran , Magbagbeola Olubunmi Abiola 
Published: April 2020

Cannabis as the most widely used illicit drugs among Nigerians has been associated with psychiatric disorders. Studies have implicated genetic predisposition in drug abuse and dependence. We therefore aimed at finding out the relationship between some dopaminergic gene polymorphisms and cannabis dependence.One hundred and four patients attending a psychiatric facility in Lagos, Nigeria who were diagnosed of cannabis dependence according to ICD‐10 were recruited for the study. Ninety six subjects who were not smoking cannabis were also recruited as a comparative group. Genotyping was carried out for Ser311Cys polymorphism of the dopamine receptor D2 (DRD2) gene and the 40bp VNTR of the dopamine transporter (DAT) gene.The Cys allele was more frequent than the Ser allele among the smokers (0.878 and 0.122 respectively), compared to the non‐smokers (0.611 and 0.389 respectively). Most of the smokers were homozygous Cys/Cys (0.433) while most of the non‐smokers were heterozygous Ser/Cys (0.798). Individuals with DRD2 Ser311 allele were more than five times as likely to use cannabis as those with Cys311(p = 0.001, OR = 4.575, 95%CI = 2.727–7.678). The 9 and 10‐repeats (9R and 10R) of the DAT VNTR were the most common repeats. Other repeats were very few and were even found in heterozygous form in combination with either 9 or 10 repeats. The 10R allele was more frequent than the 9R among the smokers (0.560 and 0.440 respectively) and also among the non‐smokers (0.726 and 0.274). While most of the smokers were heterozygous 9R/10R (0.559), most non‐smokers were homozygous 10R/10R (0.595). Individuals with at least one 10R were almost twice as likely to use cannabis as those with the 9R (p = 0.004, OR = 1.915, 95%CI = 1.225 – 2.995).The Cys311 allele of the DRD2 and the 10R of the DAT VNTR were significantly associated with cannabis smoking as individuals with these alleles were more likely to smoke cannabis.
Feeling Fragile: Chemosensitization of Metastatic Breast Cancer Cells Through the Use of 4EGI‐1 and Etoposide
Authors: Patel Anya , Jacobson Blake , De Luke , Ronan Jehnna , Kratze Robert 
Published: April 2020

Breast cancer is the most common cancer among women worldwide. High quantities of Etoposide (ETP), a topoisomerase II inhibitor, have been shown to have considerable adverse effects, therefore making chemosensitization an appropriate area to research. Combination therapies with the drug have been largely unexplored. In the past, ETP has been used to treat metastatic breast cancer in conjunction with other drugs, specifically chemosensitizers. Combining ETP with another drug as a chemosensitizer could increase its efficacy. In past studies, non‐small cell lung cancer has been treated with a novel drug compound, 4EGI‐1, which is a translation inhibitor. Combining the drugs by using 4EGI‐1 to treat metastatic breast cancer as a chemosensitizer could decrease the amount of ETP needed as well as increasing its efficacy. Here we examine the relationship between different concentrations of ETP and 4EGI‐1 and their effect on immobilized breast cancer cell culture. Cell death was used as an assay to determine the efficacy of the drug combination. We hope to show the synergistic effects of ETP and 4EGI‐1 on breast cancer cells. The cell line used was MDA‐MB‐231, a human epithelial breast cancer cell, derived from a 51‐year‐old female diagnosed with mammary adenocarcinoma. The goal of our in vitro studies is to eventually increase patient comfort in a clinical setting by reducing the necessary amount of ETP.Support or Funding InformationUniversity of Minnesota, The Nueva School
International anatomy partnerships ‐ Results of international student basic sciences internships initiated via the anatomy course
Authors: Wu Anette , Kieff Monica , Noel Geoffroy , Wingate Richard , Kielstein Heike , Sakurai Takeshi , Viranta-Kovanen Suvi , Chien Chung-Liang , Traxler Hannes , Waschke Jens , Vielmuth Franziska , Sagoo Mandeep Gill , Kitahara Shuji , Keay Kevin , Olsen Jorgen , Bernd Paulette 
Published: April 2020

IntroductionAnatomists, as scientists, are a great resource for medical students’ scientific research interests. Recently, a new role for the Anatomy course in internationalization of medical education has emerged. Here we report on student experiences from international basic sciences research internships that were initiated via the anatomy course – combining two educational aspects of anatomy: the basic sciences and internationalization of medical education.Material and MethodsA multi‐directional basic sciences research interchange was initiated as part of an international exchange program that is based on an international partnership of 13 anatomy departments.200 preclinical medical students initially participated in an online international exchange segment, before embarking on optional basic sciences internships abroad. Based on students’ preferences, anatomy faculty at 13 international medical schools worked together on sourcing and student placement into basic sciences laboratories. Areas of research included a wide range of topics (e.g., immunology, genetics, tissue engineering, diabetes research, etc). At two time points (i.e., before and after travel), a questionnaire with multiple‐choice questions, Likert scales, and open‐ended questions, assessed the students’ learning experience qualitatively.ResultsA total of 82 students participated in international travel during 2019. As of now, 51 have completed the pre travel questionnaire and 26 the post travel questionnaire. Almost all of the partner schools sent and received students. Students improved both their understanding of the basic sciences and their basic sciences research skills, formed networks for future collaboration, and experienced an international cultural interchange. The majority of students felt that the basic sciences experience was important for their careers, and they wished to continue their involvement.DiscussionAnatomy courses can foster a student’s interest in science and research, and introduce an international component to basic science experiences as study abroad programs. Providing international basic sciences research opportunities expands research options for students, including in areas of interest that are not available at the home institution, provides a baseline for future collaboration and helps students becoming leaders outside of their home institution.
Antibacterial and Antifungal Agent, Triclosan (TCS) Alters Secretion of Interleukin beta and Interleukin 6 from Human Immune Cells
Authors: Wilburn Wendy J. 
Published: April 2020

Triclosan (TCS) is an antimicrobial compound that is widely used in personal hygiene products such as mouthwash and toothpaste. TCS can be ingested or absorbed through the skin and has been found in human blood, breast milk, and urine. Interleukin (IL)‐6 and IL‐1 beta (IL‐1β) are important pro‐inflammatory cytokines produced by lymphocytes, monocytes, and other cells. Both regulate cell growth, tissue repair, and immune function, increased levels of each have been associated with a number of diseases including rheumatoid arthritis and certain cancers. TCS has been shown to inhibit the lytic function of human natural killer (NK) lymphocytes and to decrease expression of key cell surface proteins on NK cells. Here we examine whether TCS alters the secretion of IL‐1β and IL‐6 from human immune cell preparations. Human peripheral blood mononuclear cells (PBMCs) and monocyte‐depleted (MD)‐PBMCs were exposed to TCS at concentrations of 0–5 μM. Cytokine secretion was measured at 24 h, 48 h, and 6 days using enzyme‐linked immunosorbent assay (ELISA). In this study, both IL‐1β and IL‐6 secretion were altered at one or more concentration of TCS at one or more length of exposure. IL‐1β secretion was increased at 1, 2.5 or 5 μM TCS. Effects of 24 h exposure to 1, 2.5 and 5 μM TCS on IL‐1β secretion from PBMCs treated with selective MAPK pathway component inhibitors were also measured. These results indicate that TCS has the capacity to disrupt secretion of these two important pro‐inflammatory cytokines. Additionally the data show that TCS‐induced increases in IL‐β secretion were dependent on p38 MAPK.Support or Funding InformationSupported by NIH grant U54CA163066.
RNA Binding Protein FXR1‐miR301a‐3p axis contributes to p21WAF1 degradation in oral cancer
Authors: Majumder Mrinmoyee , Palanisamy Viswanathan 
Published: April 2020

RNA‐binding proteins (RBPs) associate with primary, precursor, and mature microRNAs (miRNAs), which in turn control mature miRNA levels, and post‐transcriptional gene regulation (PTR). However, the mechanistic basis of miRNA interaction and stability by RBP remains largely elusive. To understand how RBPs contribute to miRNA stability and PTR, we analyzed miRNAs that are controlled and stabilized by RBP
Fragile
X Mental
Retardation protein‐
1 (FXR1) in head and neck squamous cell carcinoma (HNSCC). We find that FXR1controls the expression of a subset of mature miRNAs, including a highly expressed oncogenic miR301a‐3p in HNSCC cells. We also observed that FXR1 controls the stability of miR301a‐3p by blocking 3′ to 5′ exoribonuclease activity of Polyribonucleotide Nucleotidyltransferase 1 (PNPT1). The miR301a‐3p is degraded by PNPT1 in the absence of FXR1 in oral cancer cells, and the degradation is rescued in co‐knockdown of FXR1 and PNPT1. Also, our in vitro findings show that FXR1 bound miRNA complex protects miR301a‐3p from PNPT1‐mediated miRNA degradation. This work also reveals that FXR1 knockdown destabilizes miR301a‐3p that degrades p21 mRNA, which leads to an increase in p21 accumulation, which explaining why overexpressed FXR1 and miR301a‐3p in HNSCC display p21 downregulation. Thus, our work illustrates the unique role of FXR1 that is critical for the stability of a subset of mature miRNAs or at least miR301a‐3p to target p21, thereby promoting the growth and proliferation of HNSCC.Support or Funding InformationDE025920 and P30 CA138313
The Notion of Cadaver Dissection in the Anatomy Curriculum to Produce Competent Physicians
Authors: Raja Dewan Saiful 
Published: April 2020

Many anatomists claim the utmost importance of cadaver dissection to produce competent physicians. Other anatomists say Cadaver Dissection is obsolete. It is a difficult task to prepare and collect embalmed cadaver. Dissection hall maintenance is costly. Exposure to chemicals of a dissection laboratory and contact to human remains is not tolerable to many medical students. Disposal of the dissected cadavers is a cumbersome task too. The number of dissection lab hours and the number of students assigned for one cadaver is variable. Many medical colleges purchased computerized dissection programs. There is a trend of decreasing cadaver dissection hours. Some of the colleges relinquished both the cadaver dissections and prosections. I searched multiple works of literature from one note and PubMed with the necessity of dissection in the anatomy instruction word. Many anatomy instructors have no medical training, and a practicing physician never participates in cadaver dissection. Due to the embalming technique, the normal color and texture of normal human body are altered. A physician learns the relevant clinically oriented anatomy during the residency programs. To get into the residency program, one needs to pass the USMLEs and Clinical Skill examinations. These examinations do not include cadaver dissection nor cadaver structure identification. It is found that a medical student without cadaver dissection assignments had the equivalent scores to the students who spent many hours in cadaver dissections.ConclusionIt is possible to become a competent physician without the experience of cadaver dissection.Support or Funding InformationNone
Inhibition of TOR in Chlamydomonas reinhardtii Leads to Rapid Cysteine Oxidation Reflecting Sustained Physiological Changes
Authors: Smythers Amanda L. , Ford Megan L. , McConnell Evan , Lowery Sarah , Kolling Derrick R.J. , Hicks Leslie M. 
Published: April 2020

The target of rapamycin (TOR) kinase is a Ser/Thr kinase and master
regulator, with roles in the regulation of nutritional sensing, protein translation, and autophagy, among others. In Chlamydomonas reinhardtii, a unicellular green algae and model organism for biofuel production and optimization, TOR has been linked to increased triacylglycerol (TAG) accumulation, suggesting that TOR or a downstream target is responsible for the elusive “lipid switch,” the protein or proteins responsible for increasing TAG formation under nutrient limitation and environmental stressors. However, when this lipid switch is activated, overall culture growth is arrested, truncating the alga’s ability to continuously produce TAGs at a level needed for widespread biofuel use.In order to engineer an effective strain for algal biofuels, the targets and signaling pathways of lipid regulatory networks must be determined. However, while TOR has been well characterized in mammalian systems, it is still poorly understood in photosynthetic systems. Previous research has used TOR inhibitors to follow phosphorylation pathways and identify potential downstream targets of TOR but little work has uncovered the role of oxidative signaling in regulation. Since TOR inhibition results in an increase in reactive oxygen species analogous to that of nitrogen deprivation, the opportunity for redox control mechanisms is significant.This study inhibited TOR using AZD8055 and monitored reversible thiol oxidation while simultaneously tracking physiological changes. By pairing these data together, reversible thiol oxidation was related to nearly every major metabolic pathway in the cell, including TAG accumulation, the tricarboxylic acid cycle, and protein translation. Additionally, reversible thiol oxidation corresponded to changes in photosynthetic activity measured through chlorophyll a fluorescence, showing a novel role for TOR regulation of photosynthesis. The delineation of redox‐controlled proteins under TOR inhibition provides a framework for further characterization of the TOR pathway in photosynthetic eukaryotes.Support or Funding InformationThis research was supported by a National Science Foundation CAREER award (MCB‐1552522) awarded to L.M.H and a National Science Foundation award (Cooperative Agreement OIA‐1458,952) to D.R.J.K. A.L.S. was funded by the NASA West Virginia Space Grant Consortium (NNX15AK74A and NNX15AI01H).
Antibacterial, antibiofilm activity and cytotoxicity of crude extracts of Ptaeroxylon obliquum (Ptaeroxylaceae) used in South African ethnoveterinary medicine against Bacillus anthracis Sterne vaccine strain
Authors: Famuyide Ibukun Michael , Eloff Jacobus Nicolaas , McGaw Lyndy Joy 
Published: April 2020

Anthrax, a zoonotic disease and a potential biological weapon for terrorism is caused by Bacillus anthracis, a Gram‐positive, sporulating bacterium. Anthrax is endemic in South Africa and primarily affects livestock and wildlife species. Problems with the control of anthrax include growing resistance to present antibiotics and disinfectants or decontaminants coupled with low antibiotic access in rural and poor settings. Therefore, it is imperative to search for new antimicrobials, especially from natural sources that could offer effective and potent alternatives. Medicinal plants are putative sources of new antimicrobials. Ptaeroxylon obliquum (Ptaeroxylaceae) is used traditionally in South Africa as an anthrax remedy in livestock. Here, the antibacterial and antibiofilm activity as well as cytotoxicity of the bark and fresh leaf crude extracts of P. obliquum was determined.A two‐fold serial microdilution assay was used to determine the minimum inhibitory concentration (MIC) of the acetone and chloroform extracts of bark and the chloroform extract of fresh leaves of the plant against B. anthracis Sterne vaccine strain. The crystal violet assay was used to determine antibiofilm activity while cytotoxicity was determined using a tetrazolium‐based colorimetric (MTT) assay against Caco‐2 intestinal cells.The MIC of the extracts ranged from 0.005 – 0.039 mg/mL compared to the positive control gentamicin (MIC = 4.9 × 10−5) with acetone bark extract being the most active (MIC = 0.005 mg/mL). Activity of extracts against B. anthracis biofilms was high (>50 % antibiofilm activity) at 0 h (prevention of biofilms; ranged between 87–99 %), and 24 h (destruction of pre‐formed biofilms; ranged between 58–93 %). The chloroform fresh leaf extract had the best antibiofilm activity. The acetone bark extract had the best total antibacterial activity (yield (mg/g)/MIC (mg/mL)) of 21 500 g/mL. This means that the mass extracted from 1 g of the acetone extract can be diluted by 21 500 times and still inhibit bacterial growth. The 50% lethal concentration (LC50) of the extracts against Caco‐2 cells ranged between 0.03–0.19 mg/mL with the chloroform fresh leaf extract being relatively the safest (LC50 = 0.19 mg/mL). The acetone bark extract had the best selectivity index (LC50/MIC) of 6. This shows that the extract has higher toxicity against the bacteria than to mammalian cells.The results support the use of the plant against anthrax in South African ethnoveterinary medicine. The extracts may be potential alternatives to chemicals as disinfectants or decontaminants, especially in rural areas where chemicals are not accessible to the farmers. The compounds responsible for anti‐B. anthracis activity, and their mechanism(s) of action, is the focus of future studies.Support or Funding InformationThe University of Pretoria is thanked for providing research support