bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon tetrachloride‐induced hepatotoxicity in weaning and adult mice
Authors: Son Seung Won , Choi Hun Ji , Jung Young-Suk 
Published: April 2020

Age‐related differences in drug‐induced liver injury (DILI) have been reported, but DILI in children has been not fully understood as compared to that in adults. In the present study, male ICR mice at two different ages, 2 (weaning) and 8 (adult) week‐old, were intraperitoneally injected with CCl4 (15.4 mg/kg), and the time‐dependent liver damage and cellular events were compared. Significant elevation of serum ALT/AST levels and hepatic centrilobular necrosis were induced by CCl4 in weaning mice, while mild liver injury was observed in adult mice. CCl4‐treated weaning mice showed higher pro‐apoptotic proteins (Bax, cleaved caspase‐3, ‐7, and ‐9), activated MAPKs (p‐JNK and p‐Erk), and ER stress indicators (ATF6 and CHOP), but lower anti‐apoptotic Bcl‐2 in their livers than those in the adult mouse livers. Weaning mice showed higher basal level of hepatic GSH due to their higher GCL and lower CDO enzyme levels. However, after CCl4 injection, hepatic GSH in weaning mice was dramatically decreased, while that in adult mice was not changed. Hepatic malondialdehyde, 4‐hydroxynonenal, nitrotyrosine‐protein adducts, and oxidized proteins resulting from oxidative stress were highly detected in CCl4‐administered weaning mice compared to the corresponding adult mice. The higher levels of CYP2E1 and 3A in the weaning mouse livers appear to be the primary reason of their higher hepatic susceptibility, and the lower GST‐π and GR in these mice also could contribute to the liver damage.Support or Funding InformationThis work was supported by the National Research Foundation of Korea (NRF) funded by the Korea government (MSIT) (NRF‐2018M3A7B4071233 and NRF‐2019R1I1A3A01058584).
Therapeutic Effects of a Small Molecule Agonist of the Relaxin Receptor in Mice with Unilateral Ureteral Obstruction
Authors: Agoulnik Alexander I. , Ng Hooi Hooi , Soula Mariluz , Rivas Bryan , Marugan Juan J. 
Published: April 2020

Diseases such as diabetes and hypertension often lead to chronic kidney failure. The peptide hormone relaxin has been shown to have therapeutic effects in various organs. In the present study, we tested the hypothesis that ML290, a small molecule agonist of the human relaxin receptor (RXFP1), is able to target the kidney to remodel the extracellular matrix and reduce apoptosis in the unilateral ureteral obstruction (UUO) mice. UUO was performed on the left kidney of humanized RXFP1 mice, where the right kidney served as contralateral controls. Mice were randomly allocated to receive either vehicle or ML290 (30 mg/kg) via daily intraperitoneal injection, and kidneys were collected for apoptosis, gene and protein analyses. UUO significantly increased pro‐apoptotic activity in both vehicle‐ and ML290‐treated mice when compared to their contralateral control kidneys. Specifically, Bax expression and Erk1/2 activity were upregulated, accompanied by an increase of TUNEL‐positive cells in the UUO kidneys. Additionally, UUO induced marked increase in myofibroblast differentiation and aberrant remodeling on the extracellular matrix. ML290 suppressed these processes through a reduction in pro‐apoptotic, fibroblastic and inflammatory markers in the UUO kidneys. Finally, the potent effects of ML290 to remodel the extracellular matrix were demonstrated by its ability to reduce collagen gene expression in the UUO kidneys. Our data indicate that daily administration of ML290 has renal protective effects in the UUO mouse model, specifically through its anti‐apoptotic and extracellular matrix remodeling properties.Support or Funding InformationThis research was supported by the U.S National Institutes of Health (NIH) Grant R01DK110167 (to A. I. Agoulnik). H. H. Ng received the American Heart Association Postdoctoral Fellowship Grant 19POST34380255, and M. Soula was supported by NIH National Institute of General Medical Sciences (NIGMS) T34GM083688 fellowship.
Cytokines Modulate the Expression of Calcitonin‐Gene‐Related‐Peptide and Substance P in Primary Rat DRG Neuron‐glia Co‐cultures
Authors: Grodzki Ana Cristina G. , Kurland Janice S. , Gorin Fredric A. , Lein Pamela J. 
Published: April 2020

In the peripheral nervous system, dorsal root ganglion (DRG) neurons are the primary sensory neuron responsible for the transmission of temperature, touch, proprioception and pain. Recently, there has been increased interest in the role of neuro‐immune interactions in peripherally‐mediated neuropathic pain. Activated immune cells that infiltrate DRG release a mixture of inflammatory mediators that play a role in the development and maintenance of pain. However, the relationship between immune cells, pro‐inflammatory mediators and sensory neurons in the development and maintenance of pain are not completely understood. In this study, we investigated the effects of the cytokines interferon gamma (IFNγ) and tumor necrosis factor‐alpha (TNFα), and the chemokine fractalkine on the expression of calcitonin‐gene‐related‐peptide (CGRP) and substance P (SP) in DRG neuron‐glia co‐cultures. IFNγ decreased CGRP and substance P expression while TNFα increased CGRP expression, preferentially in small and medium size neurons. IFNγ and TNFα, both also increased nitric oxide (NO) production in a concentration‐dependent manner, at concentrations that affected CGRP and SP expression. However, inhibitors of nitric oxide synthase (L‐NAME) and of IKKB/NFkB (TPCA‐1) did not alter TNFα effects on CGRP expression. The data from this study demonstrates that cytokines and chemokines differentially modulate the expression of CGRP and SP in DRG neurons. Understanding the regulation of these two key inflammatory neuropeptides may provide novel insights regarding the development of new and effective therapeutics for neuropathic pain.Support or Funding InformationThis work was supported by NIH (grant # R21 AG065908).
The Acute Effects of Preworkout Supplement Ingestion and Whole‐Body Resistance Exercise on Clinical Safety Markers in Resistance‐Trained Males
Authors: Koozehchian Majid S. , Hosseini Seyyed Vahid , Eynavi Hafez 
Published: April 2020

PURPOSETo examine the acute effects of ingesting a multi‐ingredient preworkout supplement (PWS) and conducting a whole‐body resistance exercise on clinical safety markers before and following exercise.METHODSWe recruited eight apparently healthy resistance‐trained males with at least six months immediate prior history of resistance training (19±1.1 yr, 173±2.6 cm, 66±2.9 kg, and 13.6±3% body fat) to participate in a randomized, double‐blind, crossover, and placebo‐controlled manner. We instructed participants to maintain their current diet and training regimens throughout the study. Supplements were a 6.5 g maltodextrin placebo (PL) and a commercially available PWS containing 1.6 g beta‐alanine, 1.0 g creatine nitrate, 1.0 g arginine alpha‐ketoglutarate, 321 mg explosive energy blended (including 160 mg caffeine anhydrous, l‐tyrosine, Tea Cor, tetramethyluric acid), 250 mg ascorbic acid, 30 mg niacinamide, 500 mcg vitamin B6, 150 mcg folate, and 20 mcg vitamin B12. In the first and second sessions, which were interspersed with a seven‐day washout period, participants ingested their assigned supplement 30 min before exercise. The exercise including a whole‐body resistance exercise initiated 30‐min after supplement ingestion. Blood samples were taken before, immediately after, and an hour following exercise. The measured blood markers included alkaline phosphatase (ALP), aspartate transaminase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), creatinine, and lactate. Repeated‐measures ANOVA and Bonferroni tests were used to analyze data. Results are expressed as mean±SD.RESULTSAnalysis of data demonstrated no significant between‐group differences for any biomarkers associated with liver enzymes such as ALP, AST, and ALT; kidney enzymes, including BUN and creatinine function; and lactate levels (all makers, p>0.05).CONCLUSIONThe acute ingestion of the PWS examined in the current study indicated no adverse effects on liver enzymes, kidney enzymes, and lactate levels, with respective responses being similar to treatment with a PL treatment. These findings agree with other studies testing similar ingredients, and more extended studies appear to be safe to perform on performance‐related outcomes.
Activation of apoptotic signaling by DAPK1 suppresses neural remodeling and functional recovery in stroke
Authors: Hong Yonggeun , Won Jinyoung , Choi Jeonghyun , Kim Joo-Heon 
Published: April 2020

Death‐associated protein kinase 1 (DAPK1), a key player in multiple types of cell death, is activated in ischemic stroke. We examined whether suppression of DAPK1 contributes to neuronal regeneration and, thereby, improves functional outcomes. Animals were subjected to middle cerebral artery occlusion (MCAo) and were administered an oxazolone‐based DAPK1 inhibitor. Animals with ischemic stroke had neurological damage and altered behavioral outcomes. However, DAPK1 inhibitor treatment reduced the expansion of the ischemic infarct and improved functional recovery. Inhibition of DAPK1 attenuated the structural abnormalities of the cortical pyramidal neurons and progressively improved neurological deficits. Additionally, while the levels of anti‐apoptotic proteins were upregulated, those of pro‐apoptotic and autophagy‐related proteins were down‐regulated in the ischemic brain by DAPK1 inhibition. Likewise, brain infarct volume and neurological deficit scores were reduced in DAPK1 KO mice. Activation of DAPK1 was exclusively associated with brain injury. These findings suggest that modulation of apoptosis by DAPK1 suppression could be used to treat ischemic stroke.Support or Funding InformationNational Research Foundation (NRF‐2013R1A2A2A01067169, NRF‐2017R1D1A1B03029565) Korea, Creative Research Program (2016–2017) of Inje University, Korea.
Stearoyl‐CoA desaturase 1 determines pancreatic β‐cell fate through regulation of DNA methylation pattern
Authors: Dobosz Aneta Maria , Janikiewicz Justyna , Borkowska Anna Maria , Kwiatek Wojciech Maria , Dobrzyn Agnieszka 
Published: April 2020

Study objectiveStearoyl CoA desaturase 1 (SCD1) is a pivotal enzyme involved in saturated fatty acids metabolism that exhibits a protective role against lipotoxicity in pancreatic β‐cells. It has been shown that SCD1 deficiency contributes to impaired insulin secretion, β‐cell failure and development of type 2 diabetes (T2D). In the present study we investigated the involvement of SCD1 in regulation of DNA methylation and expression of transcription factors (TFs) responsible for maintenance of mature β‐cells function and identity.MethodsThe experiments were carried out ex vivo on pancreatic islets isolated from wild type (WT) and SCD1 knock‐out (SCD1 KO) mice, and in vitro on INS‐1E pancreatic β‐cell line, where lipotoxicity was induced by palmitic acid treatment. Morphological and functional characteristics of islets was evaluated by ELISA assays, immunofluorescence labeling and transmission electron microscopy techniques. DNA methylation and gene expression levels were assessed by bisulfite sequencing and real‐time quantitative PCR analyses, respectively.ResultsOur data demonstrated that pancreatic islets of SCD1 KO mice are characterized by different microarchitecture, secretory granules content and functional abnormalities manifested by diminished insulin secretion and greater proinsulin secretion in comparison to WT islets. On both ex vivo and in vitro models we observed significantly reduced expression of TFs crucial to maintenance of β‐cell identity such as Pdx1, MafA, Nkx6.1 and Neurod1. Interestingly, transcriptional repression of Pdx1 and MafA was related to excessive methylation of promoter regions of those TFs. In addition, we showed that downregulation of SCD1 activity/gene expression affects global DNA methylation pattern and changes methyl groups distribution within chromosomes in pancreatic β‐cells. DNA hypomethylation which occurred in SCD1‐deficient β‐cells was followed by decreased expression of DNA methyltransferase 1 (Dnmt1). We indicated that activation of AMP‐activated protein kinase (AMPK) axis influences post‐translational regulation of Dnmt1, thereby mediating the effect of SCD1 inhibition on global DNA methylation profile in β‐cells.ConclusionsTogether, our findings suggest that SCD1 is a gatekeeper that preserves epigenetic inheritance of DNA methylation pattern in β‐cells. Thus, SCD1 protects β‐cells from lipid‐derived loss of identity in methylation‐dependent manner through regulation of expression of TFs responsible for maintenance of β‐cell identity. Our results provide additional mechanistic insights toward understanding the role of SCD1 in T2D pathogenesis.Support or Funding InformationThis work was supported by grants from the National Science Center, Poland, grants no UMO‐2017/27/N/NZ3/01987 (AMD) and UMO‐2015/19/D/NZ4/03705 (JJ), and by The National Centre for Research and Development, grant no STRATEGMED 3/305813/2/NCBR/2017 (AD).
Host‐parasite Interaction Model Using Bead‐Grown Biofilms
Authors: Abu-Hassan Diala Walid , Alkawareek Mahmoud Yousef , Hamed Rania “Ahmad Azzam” , Banat Fahmy , Al-Muhtaseb Saja 
Published: April 2020

Infectious diseases are widely spread and can significantly affect people’s lives and cause social and economic damages. Co‐culture systems have been used to investigate different types of cell‐cell interactions just like those that occur in infections between microorganisms and host cells. These techniques have many applications in biology and medicine. Although various co‐culture models using different approaches were published, more modelling strategies are being tested.In this project we present a new co‐culture model based on using agar/glass beads to grow biofilms of different types of bacteria which then can be used to infect cultures of human cells. Biofilms of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Streptococcus intermedius, and Streptococcus oralis were successfully grown using this model. Beads containing bacterial biofilms were co‐cultured with PANC1 epithelial cell line to simulate its infection. This co‐culture model proved to be a facile method to study bacteria‐human cell interaction which also can be used to evaluate the efficacy and toxicity of different drug treatments.Support or Funding InformationScientific Research Support Fund, Ministry of Higher Education and Scientific Research, Al Jubaiha, Amman, Jordan 11941.
Long‐Term High‐Fat Feeding Reduces the Numbers of Satellite Cells and Myonuclei in the Adult Murine Skeletal Muscle Fibers
Authors: Allouh Mohammed Z. , Starling-Emerald Bright , Al Jailani Mohammed A. 
Published: April 2020

High‐Fat Diet (HFD) affects the skeletal muscle fibers at both morphological and functional levels. At a functional level, it has been reported that HFD reduces the oxidative capacity and leads to insulin resistance in the skeletal muscle tissue. However, there are very limited and conflicting information about the effects of HFD on the morphology of skeletal muscle fibers. This study aimed to clarify the effects of long‐term feeding with HFD on murine skeletal muscle fibers. These effects include the size of skeletal muscle fibers, frequency of satellite cells, and number of myonuclei within the fibers. Adult male mice of the C57BL/6 strain were randomly divided into 2 groups; a control group, and a HFD group. Each group contained four mice. Food and water were provided ad libitum. At the end of a twenty‐week feeding period, the tibialis anterior (TA) muscle was dissected out from each animal and weighed. Immunocytochemical and morphometric image analyses techniques were applied to quantify the fiber diameter, satellite cell frequency, and number of myonuclei per fiber cross‐section. The HFD group showed a significant (P<0.01) decrease in TA muscle weight compared to control group. However, a significant (P<0.05) increase in the muscle fiber diameter was found in the HFD group compared to control one. In addition, significant reductions (P<0.01) in satellite cell frequency and number of myonuclei were detected in the HFD group compared to control group. This study showed that long‐term feeding with HFD increases the size of skeletal muscle fibers, which may be attributed to the accumulation of intramyocellular lipids. In addition, it reveals that HFD decreases the numbers of satellite cells and myonuclei within the murine skeletal muscle fibers.Support or Funding InformationFunds for this study were provided by a seeding grant to MZA from the College of Medicine and Health Sciences at United Arab Emirates University.
Tribbles Homolog 3 (TRB3) Expression is Modulated During Skeletal Muscle Myogenesis and Regeneration
Authors: Sougey Wenddy Wyllie Damascena , Silvestre João Guilherme , Lós Deniele Bezerra , Moriscot Anselmo Sigari 
Published: April 2020

Skeletal muscle mass and activity are primordial for homeostasis and are related to important functions such as breathing, locomotion and glucose metabolism. This tissue is susceptible to lesion from mechanical‐chemical injuries and also from the mechanical stress generated by contractions. Fortunately, skeletal muscle is highly capable of regeneration, although the cellular‐molecular mechanisms involved are still not properly understood. TRB3 is a gene that codes the homonymous protein often studied for its involvement in insulin resistance by inhibiting Akt2 activity. Because it has also been shown that TRB3 overexpression can decrease myotube formation, we decided to evaluate the TRB3 expression during skeletal muscle regeneration and also in myogenesis using C2C12‐derived myotubes as a model. We cultured C2C12 cells using DMEM 10% FBS with antibiotics as growth medium. Cells at ~80% confluence were induced to differentiation into myotubes with DMEM 2% for 2 and 4 days. Cells were then harvested and total RNA and protein were isolated for further analysis by using RT‐PCR and Western blot. Also, 16 adult male C57Bl mice (~8 weeks, ~30g) were housed in 12/12h light/dark regimen with food and water ad libitum and divided into Control and tibialis anterior‐injured by cardiotoxin (CTX, 10uM) for 1, 3 and 10 days. Statistical analyzes were conducted using t‐student test in comparison with Control Group (not injured mice) or one‐way ANOVA for nonparametric data with Dunns post‐hoc for C2C12 samples analysis, expressed in Mean +− SD and p≤0.05. All experiments were approved by the Institute of Biomedical Sciences Animal Experimentation Office Committee (6085260718). We observed elevated levels of TRB3 mRNA at 2 and 4 days of C2C12 differentiation (~2.5 fold for both time points, p<0.05). Interestingly, in spite of a clear rise in TRB3 mRNA, AKT2 (a target for TRB3) mRNA is also upregulated in differentiated C2C12 cells (~3.5 fold 4 days after differentiation, p<0.05). Likewise, GSK3b mRNA levels are elevated 4 days after differentiation (2.5 fold, p<0.05). In the regeneration model we also observed increased TRB3 mRNA levels in all time points evaluated (1 day~19 fold 3 days~9 fold and 10 days~5 fold, p<0.05). Accordingly, we preliminarily observed increased levels of TRB3 10 days after injury by Western blot. These results suggests that TRB3 might be involved in the early and late phases of the myogenic‐regenerative process and functional experiments involving manipulated TRB3 levels are ongoing.Support or Funding InformationFAPESP, CAPES, CNPq
Characterization of a Leucine‐Rich Repeat‐Containing G Protein‐Coupled Receptor
Authors: Erlandson Sarah C. , Rawson Shaun , Kruse Andrew C. 
Published: April 2020

Leucine‐rich repeat‐containing GPCRs (LGRs) are a small group of Family A GPCRs consisting of glycoprotein hormone receptors, R‐spondin receptors, and relaxin receptors. All of these receptors have large N‐terminal ectodomains of leucine‐rich repeats (LRRs), however the mechanisms that couple ligand binding in the LRRs to signal transduction are poorly understood. We have been studying the relaxin receptor, RXFP1, which is a member of the LGR family with important roles in cardiovascular and reproductive biology. Activation of RXFP1 by its agonist, relaxin, induces pleiotropic cellular responses, including vasodilation, angiogenesis, and collagen degradation. These effects in various tissues, particularly the heart, liver, and kidneys, make RXFP1 a promising drug target to treat cardiovascular diseases and multiple diseases of organ fibrosis. Despite the biomedical relevance of RXFP1, there are few molecules available to modulate receptor signaling and relatively little is known about the receptor’s molecular mechanism of activation. We have created engineered versions of the relaxin hormone with the goal of generating a molecule that can target RXFP1 with a longer serum half‐life. To study the receptor’s molecular mechanism, we optimized an expression and purification strategy for RXFP1 in complex with relaxin and its intracellular effector, the heterotrimeric Gs protein, and have been studying the complex by cryo‐electron microscopy. These studies have revealed the shape of the receptor’s LRR ectodomain, which positions the binding site of relaxin away from the GPCR transmembrane domain. Details of the receptor’s interactions with G proteins were also investigated, showing that RXFP1’s helix 8 interacts with G proteins similarly to Class B GPCRs.Support or Funding InformationFinancial support for this work was provided by the Blavatnik Biomedical Accelerator at Harvard University and an NIH F31 Fellowship (5F31GM128233) (S.C.E.).