bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of aging on APOE‐modulated AD pathology in EFAD mice
Authors: Balu Deebika , Valencia‐Olvera Ana , Collins Nicole , Salzman Ryan , York Jason , Ladu Mary Jo 
Published: November 2023

The APOE ɛ4 allele of apolipoprotein E (apoE) is the greatest genetic risk factor for Alzheimer's disease (AD) compared to APOE3, with APOE2 providing a protective effect. APOE4 is associated with accelerated amyloid‐β (Aβ) accumulation, both as amyloid plaque and soluble oligomeric forms of Aβ (oAβ), the latter considered a proximal neurotoxin. Using EFAD mice, a novel, tractable human‐APOE/familial AD‐transgenic (FAD‐Tg) preclinical mouse model, we have developed the mechanistic hypothesis that APOE4 causes a reduction in apoE lipidation, resulting in inefficient clearance of soluble Aβ, synaptic loss, and memory deficits. By 6‐months (M), E4FAD mice have greater cognitive impairment, AD pathology and soluble Aβ levels, with lower apoE lipidation levels compared to E3FAD. However, the effect of aging on EFAD mice has not been analyzed beyond 6M. In this study, at 8M, 10M, 14M and 18M, we measured amyloid deposition, neuroinflammation and tau pathology, as well apoE lipidation, and soluble levels of Aβ42, oAβ and apoE/Aβ complex. AD pathology continues with age (E4FAD > E3FAD) spreading from the subiculum and deep layers of the frontal cortex to the entire length of the cortex and particularly the thalamus. Comparison of Aβ deposition identified with an Aβ mAb vs. Thio‐S staining revealed both regional and age‐dependent changes in plaque morphology. Importantly, while the levels of soluble Aβ42 plateaued at 10M in E4FAD and 14M in E3FAD mice, oAβ levels continued to increase, from 6–18M with E4FAD > E3FAD. The predictive validity of preclinical FAD‐Tg mouse models that lack h‐APOE, the major genetic risk factor for AD, remains unclear. As the greatest risk factor for AD is age, aged EFAD mice address both these critical risk factors.Support or Funding InformationNIH (NIA) P01AG044682, R21AG030128, R21AG048498, R21AG051233, CCTS (UL1RR029879)
(−)‐Epicatechin Mitigates Oxidative Stress, Neuroinflammation and Hyperphosphorylation of TAU in Hippocampus of Senile Mice
Authors: Ramirez‐Sanchez Israel , Rodriguez Alonso , Neri Teresa , Mendoza‐Lorenzo Patricia , Ceballos Guillermo , Villarreal Francisco 
Published: November 2023

Evidence has implicated oxidative stress (OS) and inflammation as a driver of neurodegenerative pathologies such as Alzheimer's disease. We previously reported on the beneficial effects of treatment with the cacao flavanol (−)‐epicatechin (Epi) on aging‐induced OS and capacity to restore modulators of mitochondrial biogenesis in the prefrontal cortex of 26‐month‐old mice. In the present study, using a similar mouse model of aging, we examined the capacity of Epi to mitigate hippocampus OS, inflammation, hyperphosphorylation of tau protein, and soluble β‐amyloid protein levels leading to improved memory and anxiety levels. Male mice (26 month old) underwent 2 weeks of Epi treatment (1 mg/kg/day BID by oral gavage) and samples of hippocampus collected for the assessment of relevant endpoints. The assessment of the OS markers protein carbonyls and malondialdehyde levels evidence significant increases (~3 fold) with aging that are suppressed (p<0.05) by Epi. Using Western blots the protein levels of the proinflammatory molecules COX2, NFkB, TNF alpha, interleukins (1β, 5 and 6) and interferon gamma increase with aging (~2–2.5 fold) and are also significantly suppressed with treatment. Aging also leads to the hyperphosporylation of tau, increased soluble β‐amyloid levels (~ 2 fold) and reductions in nerve growth factor (~75%) which are reversed by Epi. Measures of anxiety (open field tests) and object recognition (memory) results were also improved by treatment. Altogether, results evidence a unique capacity of Epi to significantly mitigate hippocampus OS and neuroinflammation leading to improved brain function. These results may account for the beneficial effects that dark chocolate exerts on measures of memory in humans.Support or Funding InformationNIHDK98717
Erythropoietin Reverses Cognitive Deficits Following Infantile Traumatic Brain Injury: A Translational Touchscreen Investigation
Authors: Jantzie Lauren , Robinson Shenandoah 
Published: November 2023

Traumatic brain injury (TBI) is a leading cause of death and severe morbidity for infants who are born healthy. No targeted treatment currently exists to actively promote repair after early TBI, despite the high incidence of chronic, debilitating deficits. EPO is a neuro‐reparative agent with multiple mechanisms of action that may benefit infants who suffer TBI. TBI in infants increases EPO receptor expression on neural cells, and extended EPO dosing reduces neuroinflammation and enhances survival and maturation of oligodendrocytes and neurons after injury. Using a translatable preclinical model of infant TBI, we hypothesized that EPO would reverse deficits of cognition as observed on a touchscreen paradigm. Controlled cortical impact (CCI) was performed on postnatal day 12 (P12) rats of both sexes. Anesthetized rats underwent left parietal craniectomy and 0.6mm impact. On post‐injury day (pid) 1, injured rats were randomized to 6 doses of intraperitoneal erythropoietin (EPO) 3000U/kg/dose or vehicle (sterile saline) over pid 1–8. Similar to the Cambridge Neuropsychological Test Automated Battery (CANTAB) in humans, a touchscreen platform was applied to assess multiple cognitive domains. Adult rats were trained on a touchscreen operant platform by blinded investigators. Following successful training, rats performed visual discrimination (VD) and reversal tasks to assess executive function and cognitive flexibility (n=6–8/group, two way ANOVA with Bonferroni correction). Results indicate that Sham, CCI and CCI‐EPO rats are able to successfully perform VD with each group requiring a similar number of sessions to passing criteria and committing similar numbers of discrimination errors. However, when assessing reversal learning, only 57.1% of CCI animals successfully passed criteria compared to 100% of Sham and 83.3% of CCI animals treated with EPO. Notably, CCI animals committed significantly more errors and required more correction trials (1114±132) compared to Sham (730±95) and CCI‐EPO (652±61, p<0.05 for all), concomitant with increased perseveration (all p<0.05). Taken together, EPO treatment ameliorates deficits from TBI on a touchscreen platform, including error reduction and perseveration, and restores cognitive flexibility. EPO, administered in an extended post‐injury dosing paradigm congruent with its mechanisms of action, proved efficacious in reversing functional impairment after TBI in developing rats.Support or Funding InformationDedicated health research funds from the University of New Mexico, Genise Goldenson Foundation and Boston Children's Hospital.
Oxytocin Protects Against Oxidative Stress And Apoptosis‐Induced Cell Damage In Glial “U87‐MG” Cell‐Line: Role Of OXT Receptor
Authors: ALANAZI MOHAMMED , Havranek Tomas , Bakos Jan , Castejon Ana Maria 
Published: November 2023

Backgroundthe neuropeptide oxytocin, released from the posterior pituitary into the systemic circulation has been implicated in several vital physiological processes, ranging from reproduction to social and non‐social behaviors. Oxytocin has been associated with cell proliferation, protection against apoptosis, and regulation of cytoskeletal protein expression. These findings might be relevant since certain neurological disorders have been linked to low systemic levels of oxytocin (e.g. autism).Objectivewe evaluated both the anti oxidant capacity and the protective role of oxytocin against apoptosis and oxidative stress in the Glioblastoma “U87‐MG” cell line.Methodologywe developed an Oxytocin Receptor Knockdown cell line, U87MG_KD OXT‐R (astrocyte), to further analyze 1) viability rates after different stressors (H2O2, Camptothecin or DMNQ) with and without oxytocin for 24 hours 2) Anti oxidant capacity of oxytocin against H2O2 for 24 hours.ResultsIn the control cell‐line “U87‐MG”, treatment with 100nM and 1uM oxytocin significantly blunted the reduction in cell viability induced by H2O2 (p<0.01, p<0.001), Camptothecin (p<0.05, p<0.01) and DMNQ (p<0.05, p<0.001) respectively. Also, oxytocin (100 nM and 1uM) significantly reduced reactive oxygen species ROS generation when cells were exposed to 500uM H2O2 (p<0.05 and p<0.05 respectively). In contrast, oxytocin did not protect against cell loss or affected ROS production in U87MG_KD OXT‐R when cells were treated with these oxidative stress and pro‐apoptotic substances.Conclusionour results indicate that oxytocin has a protective and anti‐oxidative effect in U87‐MG and this effect is lacking when the OXTR is knockdown. These results contribute to a better understanding of oxytocin's effect and its potential role in many neurological disorders associated with abnormal cell viability and oxidative stress such as autism.Support or Funding Information1‐ President's Faculty Research & Development (PFRDG) Grant ‐ 2015–20162‐ Saudi Arabian Cultural Mission (SACM) Graduate Students Research Grant
Structural Insights into Phospholipase Cɛ: A Multi‐Method Biophysical Approach
Authors: Garland‐Kuntz Elisabeth E. , Vago Frank S. , Sieng Monita , Chakravarthy Srinivas , Jiang Wen , Lyon Angeline M. 
Published: November 2023

Phospholipase C (PLC) enzymes hydrolyze phosphatidylinositol lipids to produce second messengers, including inositol‐1,4,5‐triphosphate and diacylgycerol, which increase intracellular calcium and activate protein kinase C, respectively. PLCɛ contributes to cardiac hypertrophy, where it is chronically activated by the small G protein Rap1A, as well as to oncogenic Ras signaling pathways downstream of receptor tyrosine kinases. Specifically, Rap1A and Ras proteins are proposed to bind to the C‐terminal Ras‐association (RA) domain of PLCɛ, promoting conformational changes that increase lipase activity and/or membrane association. However, the role of the RA domains in PLCɛ activity is poorly understood. We are using small‐angle X‐ray scattering, electron microscopy, and biochemical approaches to determine the roles of the RA domains in basal regulation and activity upon G protein activation. These results provide the first structural insights into this essential enzyme and improve understanding of its roles in cardiovascular disease and cancer.Support or Funding InformationThis work is supported by the Showalter Foundation, Purdue Center for Cancer Research, and the American Heart Association (Grant 16SDG29920017 to AML).
Universal, homogenous and bioluminescent assay to monitor the activity of wide range of methyltransferases
Authors: Goueli Said , Hsiao Kevin 
Published: November 2023

Methylation/demethylation of DNA, RNA, Proteins and small molecules play major roles in modulation of the epigenome, transcriptome, neurotransmitter uptake and metabolic regulation, and thus, they are believed to be involved in a wide variety of human diseases. Recent biochemical and biological data suggest that altered enzymatic activities of several of these enzymes have pathogenic roles in cancer, inflammation, and neurodegenerative diseases. In addition to chromatin modulation, altered methylation of DNA and more recently mRNA have been recognized to regulate the transcriptome and the rate of message translation and stability. Furthermore, methylation of small molecules such as catechols and nicotinamide play critica roles in neurotransmitters uptake and function, and metabolic regulation, respectively. Thus, pharmacological modulation of these enzymes by small molecules will be beneficial in developing novel therapeutics for multiple unmet medical needs. Towards this goal of searching for activators/inhibitors of these enzymes for the development of next generation of drugs, screening assays for these modulators are urgently needed. To address these unmet needs, we have developed a novel ay hat monitors the activities of these enzymes and their modulation by small molecules. The assay is bioluminescent based, HTS formatted and highly sensitive. A unique feature of this assay is its universality since it is based on monitoring the formation of the universal product S‐adenosylhomocysteine (SAH), i.e., capable of detecting changes in activity of a broad range of methyltransferases such as DNA, RNA, protein, and small molecules. In addition, the assay has been validated for all classes of protein methyltransferases (Lysine and Arginine), and with different types of substrates (small peptides, large proteins, or even nucleosomes). This enables determining the specificity of these enzymes and their substrate requirements. The assay has high signal to background, low C.V., robust (Z′ value > 0.7), and has been validated using various plate densities such as 96‐, 384, and 1536‐well plates. A strong feature of this assay is its utility with broad range of substrates with no limitations on the use of high concentrations of substrates or the composition of the substrates (short vs. long peptides), thus enabling the generation of kinetic data and determining the mechanism of action of various modulators of methyltransferases of interest.Support or Funding InformationPromega Corp.
mRNA Structural Modelling Predicts Variability in Efficacy of Post‐transcriptional Gene Silencing Between Species
Authors: Trujillo Alexandria J , Sullivan Jack M 
Published: November 2023

Post‐transcriptional Gene Silencing (PTGS) agents, such as hammerhead ribozymes, face unique barriers when designed against an mRNA target. Hammerhead ribozymes(hhRzs) are able to cleave ‘NUH’ (N= any nucleotide H= U, A, C) sites in target mRNA. Along with sequence specificity, the NUH site must be located in a region of the mRNA that is accessible after secondary and tertiary structural folding. Our lab has developed a streamlined RNA Drug Discovery (RDD) platform and designed hhRzs that target the 266 and 1362 regions in Rhodopsin(RHO) mRNA, to develop a treatment for Autosomal Dominant Retinitis Pigmentosa, a disease that causes progressive vision loss. Bioinformatic analysis using mRNA structure prediction programs MFold, SFold, and RNA structure was conducted on fourteen species representatives to determine if the 266 and 1362 regions have similar accessibility for our ribozymes. The analysis shows that even in cases of sequence homology and close evolutionary relationships, access to the target region varies among species compared to human RHO. This suggests that during RDD efficacy and toxicity studies of PTGS agents in vitro and in vivo should be conducted against human RHO and transgenic animals expressing human RHO for the most accurate predictions.Support or Funding InformationThis work was supported majorly by NIH/NEI R01 grant EY013433 (JMS), and partially by the Department of Veterans Affairs (VA), Veterans Health Administration, Office of Research and Development (Biomedical Laboratory Research and Development) (VA Merit Grant 1I01BX000669 (JMS)), and partially by an Unrestricted Grant from Research to Prevent Blindness to the Department of Ophthalmology at the University at Buffalo‐SUNY, and also by the Interdisciplinary Science and Engineering Partnership (NSF 1102998 PI: Joseph Gardella (AJT)). The study was conducted in its entirety at the Veterans Administration Western New York Healthcare System (Buffalo, NY). Contents do not represent the views of the Department of Veterans Affairs or the United Stated Government.
Exercise Preconditioning as A Means To Protect The Kidney Against Doxorubicin‐Induced Oxidative Stress
Authors: Awwad Issam M. , D'Lugos Andrew C , Carroll Chad C , Gonzales Rayna J , Sweazea Karen L , Dickinson Jared M , Angadi Siddhartha S , Hale Taben M. 
Published: November 2023

It is well known that anthracycline‐based neoadjuvant chemotherapeutic agent doxorubicin (DOX) successfully reduces recurrences and improves survival in patients with breast cancer. However, DOX produces significant adverse effects which are permanent, increase morbidity/mortality and reduce overall quality of life. DOX, is highly toxic to the kidney, with damage resulting in part from increased oxidative stress. DOX has been shown to both increase reactive oxygen species production and decrease antioxidant enzyme expression. We have recently demonstrated that high intensity interval exercise pre‐conditioning was effective in reducing mortality associated with DOX treatment in young adult ovariectomized female Sprague‐Dawley rats. Exercise has been shown to be effective in increasing antioxidant capacity in various organs and may serve as a means to protect against DOX‐induced renal toxicity. The purpose of this study was to determine the extent to which high intensity interval exercise pre‐conditioning in ovariectomized female rats attenuated DOX‐induced reduction in renal antioxidant enzyme expression. Rats were divided into 3 groups (sedentary vehicle, sedentary DOX, exercise DOX). DOX (4mg/kg) or Veh (saline) were administered intraperitoneally bi‐weekly for a total of 3 injections resulting in a cumulative dose 12mg/kg. High intensity interval training at 85–95% VO2 peak (4×4 min bouts) was performed using a treadmill for 5 days per week starting 1 week prior to the first injection and continued throughout study duration. Animals were euthanized 5 days following the last injection, kidneys removed and tissue lysate prepared for western analysis to determine the relative expression of the antioxidant enzymes superoxide dismutase (SOD)‐1 and −2, as well as catalase. DOX tended to increase kidney weight relative to tibial length in both sedentary and exercise rats. In addition, DOX significantly reduced SOD‐1 expression in sedentary rats by approximately 40% relative to vehicle (p<0.05), and tended to reduce SOD‐2 and catalase expression. Exercise preconditioning did not prevent DOX‐induced reduction in the expression of these antioxidant enzymes in the kidney. In conclusion, DOX treatment significantly increased renal mass and reduced antioxidant enzyme expression. Although exercise has been shown to increase antioxidant enzyme expression in the heart and skeletal muscle, the present findings reveal that similar effects are not observed in the kidney. Future studies will evaluate the functional and structural impact of DOX treatment on the kidney.Support or Funding InformationValley Research Partnership Award P1201603
Resveratrol Protection of Mitochondrial Function in HK‐2 Cells Exposed to Cisplatin.
Authors: Valentovic Monica , Brown Katie , Lamyaithong Andre Benja , Dial Mason 
Published: November 2023

Cisplatin is a cancer chemotherapeutic agent widely used to control cancer to the testes, ovaries and cervix. Cisplatin is nephrotoxic and with a potential incidence of 33%. Resveratrol (RES) is a polyphenolic compound that possesses anticancer activity. Part of the mechanism for reducing cisplatin toxicity by RES may be mediated by preserving mitochondrial function and diminishing cisplatin induced oxidative stress. Our hypothesis is that RES will prevent mitochondrial impairment by cisplatin in HK‐2 cells. HK‐2 cells were selected as they are a human proximal tubular kidney cell line (HK‐2). Hk‐2 cells were plated for 48 followed by a 1 h pretreated with RES or 1% DMSO (vehicle). Renal cells were subsequently exposed to cisplatin at a final concentration of 0–50 uM for 24 h. Viability was assessed using MTT release and cell count with an n=6/group and repeated 3 separate times. Cells pretreated with 10 uM RES were protected from cisplatin cytotoxicity at 24 h. Cisplatin caused a concentration dependent decline in MTT viability after 24 h exposure to 0, 7.5 and 15 uM cisplatin. RES pretreatment for 1 h with 10 or 15 uM RES increased HK‐2 viability relative to cells exposed only to RES Vehicle (DMSO). Mitochondrial respiration was measured using a Seahorse XFp analyzer and expressed as oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). Mitochondrial function was further probed by monitoring ATP levels and cytochrome c leakage. Basal and uncoupled (FCCP) mitochondrial respiration were monitored in RES and cisplatin treated cells. Additional studies examined oxidative stress as increased protein carbonylation and 4‐hydroxynonenal adduction (4‐HNE) following cisplatin exposure of HK‐2 cells pretreated with DMSO or RES. Western analysis detected an increase in protein carbonylation with 24 h cisplatin exposure which was reversed by RES. Mitochondrial function was diminished by cisplatin and protected by RES. RES protects human proximal tubular epithelial cells from cisplatin cytotoxicity, preserves mitochondrial integrity and mitochondrial respiration.Support or Funding Information(Supported by NIH Grants INBRE 3P20RR016477‐09S4; 5P20RR016477 and 8P20GM103434 and a WV NASA Undergraduate Research Fellowship to MD.
Effects of MicroRNA‐34a on the Pharmacokinetics of Cytochrome P450 Probe Drugs in Mice
Authors: Jilek Joseph Lionel , Tian Ye , Yu Ai‐Ming 
Published: November 2023

MicroRNAs (miR) including miR‐34a have been shown to regulate nuclear receptor, drug‐metabolizing enzyme and transporter gene expression in cell models. However, the degree to which miRNAs affect pharmacokinetics (PK) at the systemic level remains unknown. Additionally, miR‐34a replacement therapy represents a new cancer treatment strategy, however it is undefined if miR‐34a therapeutics elicit any drug‐drug interactions (DDI). To address these questions, we developed a practical single‐mouse PK approach and investigated the effects of a bioengineered miR‐34a prodrug on the PK of five cytochrome P450 (CYP) probe substrates (midazolam, dextromethorphan, phenacetin, diclofenac, and chlorzoxazone) administered as a cocktail to mouse models. This approach utilized manual serial blood microsampling from a single mouse and a sensitive LC‐MS/MS assay. This approach was validated by the sharp changes in midazolam PK by ketoconazole and pregnenolone 16α‐carbonitrile as well as phenacetin PK by a‐napthoflavone and 3‐methylcholanthrene. Surprisingly, 3‐methylcholanthrene also decreased systemic exposure to midazolam, while both pregnenolone 16a‐carbonitrile and 3‐methylcholanthrene largely reduced the exposure to dextromethorphan, diclofenac and chlorzoxazone. Finally, miR‐34a had no significant effects on the PK of dextromethorphan, phenacetin and chlorzoxazone, and caused a marginal (45–48%) increase in systemic exposure to midazolam and diclofenac in mice. These findings from the single‐mouse PK model suggest that therapeutic miR‐34a might have minor or no effects on the PK of CYP‐metabolized drugs co‐administered.Support or Funding InformationThis study was supported by grants [R01GM133888] and [U01CA175315] from NIH. J.L.J. was supported by a NIGMS Pharmacology Training Program [T32GM099608].