bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum Leptin is associated with Fasting Plasma Glucose and Serum Insulin Levels independent of BMI in Haitian Americans with Type 2 Diabetes
Authors: Antwi Janet , Proulx William , Sullivan Stacey , Lavin Rebecca , Bellavia Maria
Published: June 2021

Objective

Leptin is an adipose tissue derived peptide considered both structurally and functionally as a pro‐inflammatory adipocytokine. Leptin has been associated with metabolic risks and type 2 diabetes (T2D). Haitian Americans are an understudied ethnic Blacks at risk for T2D. We aimed to measure serum leptin levels in Haitian Americans with and without T2D and to examine the relationship of serum leptin with metabolic risk factors of T2D.

Methods

Cross‐sectional analysis in 213 Haitian Americans, 100 with T2D and 113 without T2D. Fasting plasma glucose levels (FPG) were measured by hexokinase enzymatic methods (Laboratory Corporation of America, FL, USA). Fasting serum insulin levels were determined with enzyme‐linked immunosorbent assay (ELISA) using commercially available kits (Millipore, St Charles, MS, USA). Serum leptin levels was analyzed by ELISA (R&D Systems, Minneapolis, MN, USA).

Results

Serum log leptin levels were significantly higher in both females with and without T2D compared to males with and without T2D (P<0.001). Females with T2D had higher body mass index (BMI, obese) compared to males with T2D (P=0.016), while higher BMI in females without T2D (overweight) had a trend towards significance compared to males without T2D (P=0.099). Multiple linear regression demonstrated that in subjects with T2D, serum log leptin levels were significantly associated with FPG (B=‐0.004, P=0.012) and fasting serum insulin levels (B=−0.058, P=0.026) after adjustment for age, gender, BMI, total energy intake, physical activity and smoking status. The association was not statically significant in subjects without T2D after controlling for the same covariates. Serum log leptin levels were significantly associated with BMI in both subjects with (B=0.095, P=0.020) and without T2D (B=0.080, P=0.001).

Conclusion

There is a significant association between FPG and fasting serum insulin levels in Haitian Americans with T2D, independent of adiposity, demographic and behavioral factors. This may suggest that serum leptin level is an important factor of metabolic risks of T2D irrespective of obesity levels. Thus, leptin levels may be used to identify diabetes‐metabolic risk in Haitian Americans.

Support or Funding Information

This research was funded by a NIH/NIDDK grant.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Convenient and Sensitive Assay for the Screening of Lysosomal Storage Disorders
Authors: Stokes Erin
Published: June 2021

Lysosomal storage diseases such as Fabry disease comprise a rare set of disorders that may be undiagnosed until adult life when therapies, including enzyme replacement, substrate depletion, and molecular chaperones, are less effective. Routine clinical diagnoses and laboratory tests by direct enzyme assay are available only at selected specialized major research centers and are not generally available due to the requirements for dedicated and expensive reagents, equipment, and personnel. We report here the development of a convenient, sensitive and rapid continuous enzyme assay for routine screening and diagnosis that can be carried out using microtiter plate assays that is also suitable for automated multiplex, high‐throughput, and robotic analyses. The incidence of individual lysosomal storage diseases is low, but considered together these disorders comprise significant morbidity and mortality with a cumulative incidence of about 1:5,000, and newborn screening studies suggest that it could be significantly higher. Early diagnosis and treatment of Fabry disease and 24 other lysosomal storage disorders is expected to result a significant reduction in morbidity and mortality with concomitant reduction in medical support and expenses.

Support or Funding Information

NIH SBIR Grants and Royalty Income From Patents

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The lipid A 1‐phosphatase, LpxE, play multiple roles in bacteria envelope biogenesis
Authors: An Jinsu , Zhao Jinshi , Hwang Dohyeon , Gillespie Robert A. , Yang Eun Gyeong , Zhou Pei , Chung Hak Suk
Published: June 2021

Gram‐negative bacteria cell envelope is multilayered structure that consist of lipopolysaccharide at outer leaflet of the outer‐membrane, peptidoglycan at periplasmic space and glycerophospholipids which is the major component of inner‐membrane and the inner leaflet of the outer‐membrane. Distinct lipid phosphatases are thought to be involved in cell envelope biogenesis by dephosphorylating precursors such as lipid A, undecaprenyl pyrophosphate (C55‐PP) and phosphatidylglycerol phosphate (PGP). Lipid A 1‐phosphatase (LpxE) is a member of the lipid phosphatase/phosphotransferase (LPT) family, which is responsible for bacterial virulence, cationic antibiotic resistance and modulation of the host innate immune system. We report the identification of lipid phosphatase, named as LpxEAA in Aquifex aeolicus (A.aeolicus) VF5, capable of dephosphorylating all of above lipid precursors. Additionally, we show that the LpxE from the human pathogens Francisella (LpxEFN) and Helicobacter (LpxEHP) are not only able to dephosphorylating lipid A but also C55‐PP and/or PGP, respectively. This multi‐functionalities of LpxE suggests that it could participate in a wide range of bacterial envelope biogenesis, beyond the well‐established lipid A 1‐phosphatase activity. Based on our research, we hypothesized that pathogens which have LpxE could survive against various environmental changes by regulating the overall bacterial envelope biogenesis through LpxE activity.

Support or Funding Information

This work was supported by National Institutes of Health (NIH) grants (GM051796 to C.R.H.R and P.Z. and AI055588 to P.Z.) and Kist intramural grants (2E27391 to H.S.C and 2E27470 to S.H.K), We thank Dr. Ziqiang Guan for assisting mass spectrometry analysis.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Probing the Role of Peptidoglycan Metabolism in Helicobacter pylori's Helical Shape
Authors: Taylor Jennifer A. , Bratton Benjamin P. , DeMeester Kristen E. , Liang Hai , Jacobs Holly M. , Kuru Erkin , Brun Yves V. , VanNieuwenhze Michael S. , Vollmer Waldemar , Shaevitz Joshua W. , Grimes Catherine L. , Salama Nina R.
Published: June 2021

Helical cell shape is important for Helicobacter pylori's ability to colonize the human stomach. Cell shape in this Gram‐negative pathogen is determined by the cell wall, which is composed of peptidoglycan (PG), a polymer of disaccharides with an attached pentapeptide stem that can join glycan strands by crosslinking with an adjacent peptide stem. Maintaining helical shape requires the activity of two endopeptidases, two carboxypeptidases, and several non‐enzymatic proteins. This suggests that structural modification of the PG is essential for shape maintenance, but it is unclear whether structural modification alone is sufficient or if modifications act in concert with PG synthesis and/or turnover. The most widely‐adopted metabolic probe for labeling new PG synthesis is either a small fluorophore or clickable alkyne conjugated to D‐alanine, which is present in the two terminal positions in the PG peptide stem. However, this probe appears to be mainly incorporated through transpeptidation reactions, which do occur at new PG synthesis sites, but may also occur during synthesis‐independent modification of the cell wall. We generated a strain of H. pylori that expresses Pseudomonas putida N‐acetylmuramic acid (MurNAc ) recycling enzymes AmgK and MurU and is capable of incorporating the newly‐developed MurNAc‐alkyne probe into the cell wall. We are employing quantitative analysis of 3D structured illumination microscopy (SIM) images to define the different regions of the helical cell using Gaussian curvature and to measure whether D‐alanine‐alkyne and MurNAc‐alkyne are preferentially enriched at positive or negative curvature (major or minor helical axis of a helical cell, respectively). Preliminary results indicate that the two probes show different curvature enrichment and suggest that crosslinking activity occurs independently of new PG synthesis and/or crosslinking rates during synthesis differ at different parts of the cell. These results suggest a role for spatial regulation of both structural variation and new PG synthesis in maintaining H. pylori's helical cell shape. Furthermore, these results demonstrate the value of employing both metabolic probes to investigate cell growth and shape maintenance.

Support or Funding Information

This material is based upon work supported by the National Institutes of Health R01 AI094839 and U01 CA221230, the National Science Foundation Graduate Research Fellowship under Grant No. DGE‐0718124 and DGE‐1256082, and the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Development and Characterization of Antibodies to Site‐specific O‐GlcNAc modified Histones for Epigenetic Research
Authors: Orlando Ron , Popov Marla , Gutierrez‐Sanchez Gerardo
Published: June 2021

O‐glycosylation of nuclear and cytoplasmic proteins by a single β‐N‐acetyl‐D‐glucosamine moiety (O‐GlcNAc) is a common post‐translational modification that is highly dynamic and fluctuates in response to cellular stimuli. This type of glycosylation has been found on approximately a thousand human proteins to date and is thought to be nearly as widespread and abundant as protein phosphorylation. Many of the first proteins identified carrying this modification were transcription factors, and it became apparent in the last several years that O‐GlcNAc plays a significant role in chromatin remodeling and gene expression.

Given the complexity of the histone code, site‐specific antibodies are needed to begin to elucidate the hierarchy of modifications as well as the biological significance of single and multiple post‐translational modifications of the histones. We have developed and approach to provide high‐affinity site‐specific O‐GlcNAc antibodies that appear to overcome issues related to small carbohydrates being poor antigens and the O‐GlcNAc modified epitopes being self‐antigens. These site‐specific antibodies require a more elaborate characterization scheme than other antibodies as they need to demonstrate both a preference for the O‐GlcNAcylated species over the native peptide sequence and a specificity to the amino acid sequence. We use a multistep evaluation process to characterize our antibodies. 1) ELISA assay, to determine the preference of the antibody to the O‐GlcNAcylated peptide over the unmodified form; 2) Cross‐reactivity of the antibody to other peptide sequences modified with O‐GlcNAc; 3) Immunoprecipitation increasing wash stringencies and 4) Evaluation of the site‐specific O‐GlcNAc histone antibodies for their potential as ChIP‐Seq reagents. Using this process, we have authenticated our site‐specific O‐GlcNAc antibodies and have demonstrated that they possess the preference and specificity needed for epigenetic research.

Support or Funding Information

Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Numbers 1R43GM110887‐01 and R44GM110887‐02.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Activation of SirT1 and NAMPT preserves late‐in‐life fertility of female Nothobranchius guentheri.
Authors: Shay Kate Petersen , Thomas Nicholas O. , Lee Youngjoo , Drake Andrew C. , Ferguson Lindsey G. , Chappell Patrick
Published: June 2021

The decline of female reproductive function is an early phenotype of aging, occurring only midway through the lifespan. Yet, women's ability to delay pregnancy and preserve fertility is an important reproductive freedom. The number of women delaying pregnancy continues to rise in industrialized societies due to personal or socioeconomic circumstances, often resulting in subfertility or difficulty conceiving. There are few defined mechanisms associated with this etiology, and equally few effective therapies. To combat this problem, we used a novel emerging model, Nothobranchius guentheri, with a lifespan of only 9–12 months, that recapitulates the age‐associated spectrum of changes that adversely affect human fertility. We hypothesized that activating SirT1 would maintain female fecundity into late life. SirT1 is an NAD+ dependent histone deacetylase, whose activity is regulated by the nicotinamide to NAD+ salvage pathway, especially the rate‐limiting enzyme NAMPT. In order to increase SirT1 activation via NAMPT, we fed N. guentheri a diet containing the polyphenol resveratrol (RSV) at 300 μg RSV/g food, beginning at sexual maturity. Our previous work showed that RSV‐fed fish at 5 months of age had significantly increased ovarian NAMPT protein levels, and our current data confirms that this result continues into late life (9+ months of age). Furthermore, we found an age‐related decline in NAMPT protein that was overcome by RSV supplementation. For the first time, we show that SirT1 activity, which declines with age, is preserved in the ovaries of our RSV‐fed model. Female N. guentheri fed RSV into late life also showed increased embryo production compared to those on Control diet without RSV. These results suggest that activating SirT1 via increasing NAD+ may have a positive effect on female fertility, and that dietary interventions may become an effective therapy to combat reproductive senescence.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Obesity and Heart Steatosis: the Potential Role of the Receptor for Advanced Glycation End Products (RAGE)
Authors: Romanelli Massimiliano Marco Corsi , Vianello Elena , Tacchini Lorenza , Bandera Francesco , Dozio Elena
Published: June 2021

Obesity is one of the leading risk factors for cardiovascular diseases. Most of the obesity‐related complications are due to the ectopic accumulation of fat in tissues different from the adipose one, as liver and heart, a condition that can promote organ damage and dysfunction. The receptor for the advanced glycation end products (RAGE) is up‐regulated in many tissues in obesity and has been related to ectopic lipid accumulation in the liver. No data are available about RAGE and heart steatosis, instead.

By using lean (n = 5) and obese non‐diabetic (n = 5) Zucker rats (age: 20 weeks) (investigations have been conducted in conformance with the FASEB Statement of Principles for the use of Animals in Research and Education. Protocol Number 325/2015PR – 2015/04/05, Italian Ministry), we tested the hypothesis that in obesity, the accumulation of lipids in the heart may be mediated, at least in part, by RAGE.

Heart tissues were studied in terms of lipid accumulation, RAGE tissue expression, activation/modification of specific genes (n=84) involved in lipid metabolism (RT2 Profiler PCR Array, PARN‐007Z, QIAGEN). The following methods were used: red oil staining, real time RT‐PCR and Western blot.

We did not observed any difference in heart fat content between lean and obese rats. Heart RAGE levels, both as gene and protein, were almost the same in the two groups. Among the 84 genes evaluated, 6 genes were significantly up‐regulated, of which 4 promoting fatty acid metabolism (Acaa2, Acadl, Acadm, Acot9), 1 fatty acid transport (Crat) and 1 tryacilglycerol metabolism (Gpd1).

Uncomplicated obesity in 20‐week old rats is not associated with fat accumulation in the heart. The lack of RAGE hyper‐expression and the increased fatty acid metabolism seem to play a protective role against fat‐induced heart damage.

Whether fat accumulation may be promoted by aging and the onset of obesity‐related complication (i.e. diabetes) needs to be explored.

Support or Funding Information

Università degli Studi di Milano and IRCCS Policlinico San Donato

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Short‐term Changes in Left Ventricular Dyssynchrony Leads to Congestive Heart Failure
Authors: Hurtado Jasmin Jessica
Published: June 2021

Ventricular dyssynchrony (VD) may lead to congestive heart failure (CHF). VD is characterized by a difference in the timing of contractions in the ventricles of the heart and has become a prominent pathophysiological feature of CHF. While studies have been done to understand the long‐term effects of VD that lead to CHF, little is known on the short‐term changes associated with VD. This study explores the acute effects of induced VD in‐vivo. Animals will undergo left ventricular pacing to induce VD and changes in mitochondrial structure and function will be analyzed to determine if abnormalities lead to apoptosis and cardiac remodeling. In this study, tissue homogenates from control and paced animals will be used to perform western blot analysis to investigate the changes in expression of mitochondrial respiratory chain complexes and proteins involved in apoptosis. We will measure adenosine triphosphate levels (ATP) to assess overall mitochondrial function. It is expected that VD increases cell death as a result of mitochondrial dysfunction, leading to activation of a fibrotic response. Immunohistochemistry will be used to investigate neutrophil infiltration and myofibroblast formation to confirm the activation of a fibrotic response. We will also evaluate reactive oxygen species and matrix metalloproteinases activities, which implicate cell injury and death that results in cardiac remodeling. We hypothesize that induced left ventricular pacing in a non‐congestive heart failure model will create short‐term changes that alter cardiovascular structure and metabolism. It is important to understand the short‐term physiological changes that result from dyssynchrony because electro‐mechanical conditions found in the absence of CHF can result in long‐term effects that may eventually lead to CHF.

Support or Funding Information

This research project will be supported through FATSA funding by Dr. Katrina Yamazaki.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Clinical Biomarkers of Congestive Heart Failure Significantly Correlate with Pancreatic Trypsin and Lipase Levels in Human Blood Plasma
Authors: Courelli Vasiliki , Courelli Asimina , Mills Paul , Schmid‐Schoenbein Geert
Published: June 2021

We recently have shown that pancreatic enzymes entering the circulation after a rise in intestinal permeability may cause multiple organ dysfunctions. Increased intestinal permeability occurs in congestive heart failure (CHF), for example due to reduction of cardiac output with hypoperfusion of the small intestine. We hypothesize that elevated intestinal permeability during CHF allows digestive enzymes, such as pancreatic trypsin and lipase, typically found in the lumen of the small intestine, to enter the systemic circulation. Our goal is to determine the levels of pancreatic trypsin and lipase and their correlation with clinical biomarkers of inflammation, and functional measurements of the heart and sympathetic nervous system. Blood from 35 (19 CHF and 16 non‐CHF Controls) patients at rest and analyzed by Western Blot for pancreatic lipase and trypsin and for inflammatory markers by ELISA assays for TNF‐a, IL‐6, BNP, ICAM, p‐Selectin, CRP, differential leukocyte counts and adrenergic sensitivity assays using isoproterenol. Clinical measurements such as age, body weight, BMI, and cardiac ejection fraction were recorded. The results showed significantly higher levels of trypsin, lipase, as well as TNF‐a, IL‐6, BNP, p‐Selectin, CRP, and neutrophil count. No change in monocyte, eosinophil, and basophil counts of CHF patients were seen when compared to Control. There were significant correlations between pancreatic trypsin levels and TNF‐a, BNP, and neutrophil count, and also between pancreatic lipase and TNF‐a, IL‐6, BNP, CRP, p‐Selectin, ejection fraction, neutrophil count, and Isoproterenol response. These results suggest that the protein levels of pancreatic digestive enzymes in the systemic circulation are elevated. The levels correlate with functional metrics of CHF and potentially play key roles as CHF biomarkers and in the analysis of the loss of cardiac function.

Support or Funding Information

National Institutes of Health Grant GM 85072

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Elastic lamina fragmentation in sickle mice can be rescued by JNK‐Cathepsin inhibition
Authors: Song Hannah , Keegan Philip M. , Denby Avery J. , Clark Alexus , Selma Jada , Anbazhakan Suhaas , Botchwey Edward A. , Platt Manu
Published: June 2021

Sickle cell disease (SCD) is the most common inherited blood disorder, affecting 100,000 people domestically, and an additional 300,000 babies with SCD are born globally each year. Children with sickle cell anemia have increased stroke risk, but mechanisms underlying arterial vasculopathy are not well defined. Previously, we have shown that adhesion of peripheral blood mononuclear cells (PBMCs) from people with SCD to human aortic endothelial cells (ECs) significantly increased active cathepsin K and V enzymes compared to wildtype PBMCs suggesting that inflammatory cells from SCD contribute to pathologic vascular remodeling. In this study, Townes humanized knock‐in sickle transgenic mice were used to test the hypotheses to decode mechanisms developing cerebral vasculopathy and to pursue pharmaceutical intervention studies to hamper vascular remodeling. Carotid arteries from sickle mice (SS genotype) showed elastic lamina fragmentation as early as 3 weeks old compared to heterozygous littermate controls (AS) quantified by significantly higher elastin break numbers per artery (n=4, p<.05). In addition, expression of cathepsin K, a powerful elastase, was increased in carotid arteries in SS mice measured by immunostaining, and active cathepsin K and V were detected in aortas of SS mice by zymography confirming accelerated proteolytic degradation. To block upstream signaling to cathepsin K and reduce elastin fragmentation and arterial remodeling, c‐jun N‐terminal kinase (JNK) was inhibited with SP600125 by daily intraperitoneal injections for 8 weeks from 3‐week‐old age (3wk+8wk treatment) or from 11‐week‐old (11wk+8wk treatment). We hypothesized that inhibiting JNK/cathepsin pathway at earlier age will prevent the onset of arterial remodeling, and at later age, we might be able to regress the arterial remodeling or at least to halt the progression of elastin fragmentation. Accordingly, SP600125 injection significantly reduced carotid arterial remodeling indicated by elastin fragmentation and artery perimeters in SS mice at younger age. This suggests that arterial remodeling due to sickle cell anemia is mediated by JNK signaling, perhaps through cathepsin K proteolysis of elastin, and more importantly, that this occurs in Townes SS mice, demonstrating their utility for mechanistic studies of arterial vasculopathy and complications due to sickle cell anemia.

Support or Funding Information

AHA, NIH

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
siRNA Mediated Knockdown of MLF1 Gene Suppressed the Proliferation and Colony Forming Ability of Human Lung Cancer Cells.
Authors: Wang Hongtao , Yang Jin , Zhu Guoliang , Yan Ruxue , Zhang Yao , Wang Xiaojing
Published: June 2021

Background

Lung cancer is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. Myeloid leukemia factor 1 (MLF1) is a protein involved in myeloid cell differentiation which regulates the cell cycle and the expression of numerous genes. The role of MLF1 in hematologic cancers is well established, As yet, there is little knowledge of MLF1 expression and biological function in lung cancer. Here, we investigated the role of MLF1 in lung cancer using a variety of cell lines along with patient samples to determine whether MLF1 played a significant role in this devastating disease.

Materials and Methods

Lung cancer cell lines (A549, H1975, HCC827, and NCI‐H460) and primary lung tissue were used to assess the relative levels of MLF1 in lung cancer. The lung cancer cell line A549 was lentivirally transfected to silence endogenous MLF1 gene expression, which was confirmed by real‐time quantitative PCR (qPCR). Cell proliferation was assessed through fluorescence imaging and MTT assays. Cell cycle analysis was performed utilizing flow cytometry and formation of cell colonies evaluated microscopically.

Results

Proliferation of A549 cells was significantly inhibited in cells where MLF1 was silenced compared to controls. Cell cycle analysis indicated that cell cycle phases were not significantly changed upon silencing of MLF1 in lung cancer cells. A significant increase in apoptosis was observed in MLF1‐knockdown cells, while a significant decrease in number of cell colonies formed was observed in MLF1‐knockdown cells compared to controls. In most, but not all, human lung cancer tissue samples MLF1 was upregulated.

Conclusion

In summary, MLF1 promotes the proliferation and colony forming abilities of lung cancer cells and significantly decreases apoptosis while have no impact on cell cycle. Further studies with larger sample sizes are needed 1) to conclude whether human lung cancers upregulate MLF1, 2) to reveal the mechanism of action for MLF1 in lung carcinogenesis and 3) investigate MLF1 gene therapy for the treatment of lung cancer.

Support or Funding Information

This work was supported by Key Program of Natural Science Research of Higher Education of Anhui Province (Grant KJ2016A472 KJ2017A241), Key program for excellent young talents in college and university of Anhui province (Grant gxyqZD2016168), National Natural Science Foundation of China (Grant 81772493), and College students' innovation and entrepreneurship training project (Grant 201610367007)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The effects of methylmercury on breast cancer cells in Danio rerio
Authors: Cressey Lauren , Christensen Emily , Conn Brandon , Morrow Sara , Zhang Raymond , Benoit Janina , Gaudet Hilary
Published: June 2021

Metalloestrogens are small ionic metals that activate the estrogen receptor (ER). Studies have shown that when metalloestrogens bind to the ER, there is an increase in transcription and expression of estrogen‐regulated genes, which induces proliferation of estrogen‐dependent breast cancer. Methylmercury (MeHg), a metalloestrogen, is present in the environment and is toxic at moderate to high concentrations. However, at lower concentrations MeHg may promote the proliferation of ER‐positive breast cancers and protect cells against pro‐apoptotic signals. To investigate the effects of MeHg treatment on breast cancer cells in vitro, MCF7 breast cancer cells were treated with concentrations of MeHg ranging from 1 nM to 100 mM. MeHg analysis was used to quantify intracellular mercury concentrations and cell proliferation and apoptosis were determined by cell counting and Annexin‐V staining, respectively. We defined a protocol that maximizes cellular exposure to mercury and we found that treatment of human ER‐positive breast cancer cells with 1 nM MeHg promoted proliferation, while treatment with a concentration of 100 nM induced apoptosis. Investigations into the effects of MeHg treatment of zebrafish on breast cancer growth and progression are currently underway. Clarifying the effects of MeHg on breast cancer will improve our understanding of how environmental toxins affect tumor progression and may lead to the development of future therapeutic strategies.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
OTUD7B upregulation predicts a poor response to paclitaxel in patients with triplenegative breast cancer
Authors: Lin Yuan‐Feng , Chiu Hui‐Wen , Hsiao Michael
Published: June 2021

Paclitaxel is a first‐line chemotherapeutic for patients with breast cancer, particularly triple‐negative breast cancer (TNBC). Molecular markers for predicting pathologic responses to paclitaxel treatment is thus urgently needed since paclitaxel resistance is still a clinical issue in treating TNBCs. We investigated the transcriptional profiling of consensus genes in HCC38 (paclitaxel‐sensitive) and MDA‐MB436 (paclitaxel‐resistant) TNBC cells post‐treatment with paclitaxel. We found that OTUD7B was downregulated in HCC38 but upregulated in MDA‐MB436 cells after paclitaxel treatment at cytotoxic concentrations. Moreover, our data showed that OTUD7B expression causally correlated with IC50 of paclitaxel in a panel of TNBC cell lines. Moreover, we found that OTUD7B upregulation was significantly detected in primary breast cancer tissues compared to normal breast tissues but inversely correlated with tumor growth in TNBC cells. Besides, the increased levels of OTUD7B transcript appeared to causally associate with invasive and metastatic potentials in TNBC cells. In assessments of recurrence/metastasis‐free survival probability, high‐levels of OTUD7B transcripts strongly predicted a poor prognosis and unfavorable response to paclitaxel‐based chemotherapy in patients with TNBCs. In silico analysis suggested that OTUD7B regulation, probably owing to miR‐1180 downregulation, may negatively regulate the NF‐kB‐Lin28 axis which in turn triggers Let‐7 microRNA‐mediated caspase‐3 downregulation, thereby conferring paclitaxel resistance in TNBCs. These findings suggest that OTUD7B may be a useful biomarker for predicting the anti‐cancer effectiveness of paclitaxel and could serve as a new drug target for enhancing the canceridal efficiency of paclitaxel against TNBCs.

Support or Funding Information

This study was supported by the Ministry of Science and Technology, Taiwan (MOST 105‐2320‐B‐038‐021‐MY3 and MOST 104‐2320‐B‐038‐061‐MY3)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Suppression on Adipocyte Differentiation of Human Bone Marrow‐Derived Mesenchymal Stem Cell (hBMSC) by a Phytoestrogen Diarylheptanoid
Authors: Sutjarit Nareerat , Weerachayaphorn Jittima , Suksamrarn Apichart , Blair Harry Colbert , Piyachaturawat Pawinee
Published: June 2021

Osteoporosis is a common metabolic bone disease characterized by low bone mineral density and increased risk of fractures in elderly. Low bone mass in osteoporosis is often associated with an increase in bone marrow adipogenesis. Marrow adipocytes secreted a number of bioactive molecules that suppress osteoblast differentiation leading to bone loss. The inhibition of marrow adipogenesis with an increase in osteogenesis is one of the potential therapeutic interventions for treatment of osteoporosis in postmenopausal and aging women. The present study investigated the effects of a diarylheptanoid phytoestrogen, (3R)‐1,7‐diphenyl‐(4E, 6E)‐4,6‐heptadien‐3‐ol (DPHD) from Curcuma comosa (Zingiberaceae family) on human bone marrow‐derived mesenchymal stem cell (hBMSC) proliferation and adipogenic differentiation. DPHD (0.1–10 μM) increased hBMSC cell proliferation but inhibited adipogenic differentiation, maturation of adipocytes with suppressions of adipogenic genes and proteins; peroxisome proliferator‐activated receptor γ (PPARγ), lipoprotein lipase (LPL) and fatty acid binding protein 4 (FABP4). In addition, the anti‐adipogenic activity of DPHD at 0.1 and 1 μM were abolished by ICI 182, 780, an estrogen receptor (ER) antagonist whereas the anti‐adipogenic activity of 10 μM of DPHD was not completely inhibited by ICI 182, 780. Therefore, the anti‐adipogenic activity of DPHD particularly at low dose is, at least, mediated through ER. The investigation on the non‐estrogenic effect of anti‐adipogenic effect of DPHD is undergoing.

Supported by Mahidol University research grant and the Science Achievement Scholarship of Thailand (SAST).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Tissue Morphology and Expression of Myelin Basic Protein and Inducible Nitric Oxide Synthase in Wistar Rats Treated with Sodium Arsenite: The Beneficial Effects of Ethanol Leaf Extract of Tridax Procumbens
Authors: Samuel Ekundayo Stephen , Olopade James Olukayode , Gbadegesin Michael Adedapo , Odunola Oyeronke Adunni
Published: June 2021

Arsenical compounds cause significant issues in both humans and animals including an increased risk of developing cancer. In the present study, the role of Tridax procumbens leaf extract (TPLE) on the toxicities caused by sodium arsenite in rats was assessed. Thirty‐two male Wistar rats (80–100 g) were equally assigned into four groups (A–D) and treatment was as follows: Group A (control) were administered 1 ml/kg body weight (bwt.) olive oil; B: 2.5 mg/kg bwt sodium arsenite (SA); C: 100 mg/kg bwt TPLE; D: 100 mg/kg bwt TPLE and 2.5 mg/kg bwt SA. TPLE was administered daily for 14 days while SA was given on day 7 and 14. The route of administration was oral. Histological analysis and expression of inducible nitric oxide synthase (iNOS) (in liver, lung, cerebrum and cerebellum) and myelin basic protein (MBP) (in cerebellum) was performed. Histological examinations showed that sodium arsenite caused disruptive lesions in the liver, lungs and cerebral cortex of rats in group B. However, Tridax procumbens extract ameliorated these effects when co‐administered with arsenite in group D. There was significant elevation (p<0.05) in the expression of iNOS protein in the tissues of rats in group B when compared to other groups as revealed by immunostaining. In addition, the white mater cells of the cerebellum showed significant elevation (p<0.05) in the expression of myelin basic protein in group C as compared to groups A, B and D when quantified. In conclusion, the ethanol leaf extract of Tridax procumbens shows beneficial effects against sodium arsenite induced toxicities in Wistar rats.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Antioxidant and anti‐apoptotic effect of Gallic acid on doxorubicin‐induced testicular and epididymal toxicity
Authors: Oyeyemi Matthew Olugbenga , Moyinoluwa Olusoji Adetokunbo , Asenuga Ebunoluwa Racheal , Omobowale Temidayo Olutayo , Ajayi Olusola , Oyagbemi Ademola Adetokunbo
Published: June 2021

The effect of Gallic acid (GA) on doxorubicin (DOX) induced testicular and epididymal toxicity was investigated in experimental rat model. The rats were randomly divided into six groups of 10 animals per group. Rats in group A received clean tap water ad libitum. Rats in group B were administered DOX intraperitoneally at 15 mg/kg on the eighth day of the experiment. Animals in groups C and D received 60 and 120 mg/kg GA orally for 7 days with 15 mg/kg DOX on the eighth day. Rats in groups E and F received 60 and 120 mg/kg GA alone orally for 7 days. The animals were sacrificed 24 hr after the last administration. DOX administration led to a significant (p < 0.05) increase in hydrogen peroxide and malondialdehyde levels with significant reduction in antioxidant enzymes and reduced glutathione levels. DOX administration also led to a significant increase in total sperm abnormalities and prolactin together with a significant decrease in testosterone levels. Immunohistochemistry revealed higher expressions of caspase 3 in the testicular tissues of rats that received DOX alone. Together, pre‐treatment with GA attenuated markers of oxidative stress, reversed sperm abnormality and ameliorated the observed aberration in plasma testosterone and prolactin levels.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cytoprotective Effect of two Flavanoids ‐ Catechin and Epicatechin, Against Oxidative Stress Induced by Cumene Hydroperoxide, in MCF‐7 Cells
Authors: Alghamdi Raed , Kerr Stephen G.
Published: June 2021

Reactive Oxygen Species (ROS) are generated during normal cellular metabolic activity, especially in the electron transport chain and in biological redox reactions. Cumene Hydroperoxide, (CHP) a potent source of ROS, is commonly used in the chemical manufacture of phenols, acetone and polymers and can result in inadvertent exposure to individuals working in this chemical industry. CHP is known to initiate lipid peroxidation and increase ROS levels in membranes, which can lead to oxidative stress and cell death. The aim of the study was to investigate the cytoprotective activity of two flavonoids, catechin and epicatechin against the oxidative stress induced by CHP. The method involved comparing the % cell viability between cells treated with CHP for 4h alone and cells pretreated with catechin or epicatechin for 24 or 48 hr prior to treatment with CHP. MTS cell proliferation assays (Abcam) was used to determine cell viability after exposure. Approximately 1×104 cells/100μL/well of MCF‐7 cells were seeded in a 96‐well plates. After 24 hours, the cells were treated with CHP (50–350 μM) for 2h, 4h or 24h to determine viability. Cells were also treated with catechin (100–500μM), epicatechin (100–500μM), DMSO or control for 24 or 48 hr. Additionally, cells were pretreated with catechin (100–500μM) or epicatechin (100–500μM) and then exposed to 100μM CHP for 4 hours. % cell viability was then determined by the MTS assay system. The results of individual treatments indicated that there was a concentration dependent cell toxicity of CHP at concentrations > 50μM CHP compared to control when cells were exposed for 4 hr to CHP (IC50 = 100 μM). All concentrations of catechin and epicatechin showed no significant loss of cell viability as compared to the control after both 24 and 48h hr exposure. In the pre‐treatment studies, 100μM of CHP showed 50% decrease in cell viability after 4h of treatment, however when the cells were pretreated for 24 hr with catechin (400–500 μM) or epicatechin (400–500 μM) there was protection of 10–20% from the cytotoxic effects of CHP. Concentrations lower than 400 μM of catechin and epicatechin did not show protection. At 48h of pretreatment with catechin and epicatechin, enhanced protection (20 – 30 %), compared to the 24 hr pre‐treatment, was observed with 300–500 μM concentrations of catechin and epicatechin. The results clearly demonstrate that catechin and epicatechin at concentrations of 300 – 500 μM are cytoprotective to MCF‐7 cells against oxidative stress induced by exposure to 100 μM CHP.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Identifying Diazepam Induced Alterations in GABA Type A Receptor Synaptic Plasticity
Authors: Lorenz‐Guertin Joshua , Das Sabyasachi , Pardo Sammy , Molleur Dana , Weintraub Susan , Jacob Tija C.
Published: June 2021

The mechanisms underlying tolerance to the benzodiazepine (BZD) drug class are poorly understood. BZDs potentiate the actions of gamma‐aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the adult brain, through positive allosteric modulation of γ2 subunit containing GABA type A receptors (GABAAR). Our work uses the classical BZD, diazepam (DZP), for in‐vitro and in‐vivo experiments combined with novel live‐imaging and biochemical methods to identify BZD‐induced changes in GABAAR signaling. Previous findings from our lab and others have implicated trafficking mechanisms in the loss of BZD potentiation associated with tolerance. Microscopy studies of endogenous GABAARs in rat cortical neurons indicate 24 hr exposure of 1μM DZP causes a reduction in extrasynaptic γ2 levels and modification of the inhibitory synaptic scaffolding protein gephyrin. Immunoprecipitation experiments uncover enhanced ubiquitination of the γ2 subunit and reduced total levels in‐vitro following DZP. Biochemical studies of mice injected with 10 mg/kg DZP vs vehicle also show a significant decrease in γ2 subunit and total gephyrin cortical levels 12 hr post DZP injection. Live‐imaging studies using a novel GABAAR γ2 subunit encoding a N terminal fluorogen‐activating peptide (FAP) and pH‐sensitive green fluorescent protein (γ2pHFAP) identified elevated lysosomal targeting of γ2 following DZP. Furthermore, RFP‐gephyrin and γ2‐GABAARs exhibit enhanced synaptic diffusion rates after 24 h DZP as measured by fluorescence recovery after photobleaching experiments. Overall, our work suggests DZP treatment decreases γ2 GABAAR inhibitory function by reducing synaptic dwell time and surface levels after one day of exposure, which may contribute to the formation of DZP tolerance.

Support or Funding Information

This work was generously funded by T32GM008424, the Whitehall Foundation, the William C. deGroat neuropharmacology departmental fellowship and Pharmacology and Chemical Biology Startup Funds. The FAP, MG dyes, and critical guidance was provided by Ming Zhang, Brigitte Schmidt, and the Waggoner Lab at Carnegie Melon University. S. Das performed animal injections and tissue collection.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Organ Distribution and Clearance of (3,4)‐Methylenedioxypyrovalerone (MDPV) Enantiomers in Female and Male Rats after Intravenous Administration of Racemic MDPV
Authors: Hambuchen Michael D. , Hendrickson Howard P. , Gunnell Melinda G. , McClenahan Samantha J. , Owens S Michael
Published: June 2021

The objective of these studies was to characterize the organ distribution and clearance of (S)‐ and (R)‐MDPV in female and male Sprague Dawley rats after administration of (R,S)‐MDPV, hypothesizing that there would be enantiomer and sex dependent differences in organs most relevant to MDPV pharmacology such as the brain, heart, and liver. After administration of an intravenous 3 mg/kg dose of (R,S)‐MDPV, male and female rats (n=4–5/time point of collection/sex) were euthanized, and blood, brain, kidney, liver, heart, and spleen were rapidly collected at 5, 20, 60, 90, and 120 min after dosing. (S)‐ and (R)‐MDPV enantiomers were quantified in serum and homogenized organs by a chiral liquid chromatography tandem mass spectrometry technique. While substantial concentrations of both enantiomers accumulated in kidney tissue of both sexes, unchanged renal clearance was only a minor contributor to MDPV total body clearance (0.6 – 1.5%). These data indicated that MDPV metabolic clearance was the major route of elimination of unchanged MDPV. In the liver, concentrations of both enantiomers were substantially lower than in the kidney, and, interestingly, there were significantly (p<0.05) lower liver concentrations of (S)‐ than (R)‐MDPV in both sexes. These data indicated that the liver had a higher intrinsic metabolic clearance for the (S)‐enantiomer than the (R)‐enantiomer. This may also explain why the blood concentrations of (R)‐MDPV were consistently higher than the concentrations of (S)‐MDPV. There was a time‐dependent increase in the ratio of the more potent (S)‐ compared to (R)‐enantiomer in the brain and heart in both sexes. Also, measures of brain concentrations of both enantiomers were significantly (p<0.05) elevated in male compared to female rats. In conclusion, renal clearance of unchanged MDPV was insubstantial in both sexes. Clearance of MDPV was predominantly metabolic with the liver preferentially eliminating (S)‐MDPV. Additionally, the brain and heart S/R enantiomeric ratio showed significant (p<0.05) increases over time in male and female rats. This may contribute to (S)‐MDPV having greater potency than (R)‐MDPV at sites of action in these two organs.

Support or Funding Information

Funded by NIDA grants DA039195 and T32 GM106999

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Impact of Sex and Exercise on Methamphetamine Preference in a Rat Animal Model
Authors: Purpura Mari , Kippin Tod E. , Williams Serina , Barkas Christina , Adams Julia
Published: June 2021

Methamphetamine (METH) abuse remains an extremely serious problem in the United States. METH has a long duration of action, and therefore leads to prolonged stimulant effects. Currently, there is limited information on the individual differences in vulnerability to substance use disorder (SUD) and how subject factors may impact the selection of METH over a competing reinforcer. Explore the factors contributing to addiction vulnerability for METH in an animal model by comparing sex, dose and ITI. Expand our understanding of the relation between exercise and addiction. If the reward for exercise and drug taking have overlapping circuitry, then engaging in exercise may reduce the need for drugs. To explore factors contributing to addiction vulnerability for METH in an animal model, we compared sex, dose (0.05 and 0.1 mg/kg/inf IV), short (20 s) or long (10 min) inter‐trial intervals (ITI) and the effects of exercise on the behavioral allocation of effort on drug taking. Rats were allowed voluntary exercise in Whamann wheels (6 hr/day, 4 weeks) followed by assessment of choice between METH (1 mg/kg/inf IV, FI20s) or food (2□3×45 mg, FI20s) reinforcement in standard operant chambers. There was a significant interaction between sex and dose (F,145)=5.765, p=0.021. ITI of 20 s and dose of 0.1 mg/kg/inf was the most preferred combination and females exhibited higher and more plastic (i.e. dose dependent) selection between METH over a competing reinforcer. There was a negative relationship between running wheel rotations/hour and preference for METH, and a significant effect of treatment (exercise versus control) amongst the METH preferring rats F(1,11)=5.133, p=0.045. Engagement of voluntary exercise may decrease vulnerability and increase resilience to the development of a SUD amongst a subpopulation that is initially METH preferring. Generally, the results of this study are consistent with the growing body of clinical and preclinical evidence demonstrating that females exhibit higher addiction vulnerability for stimulant drugs of abuse.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.