Medicine and Health Sciences Commons^™

Role Of The Lpa2 Receptor In Protecting Against Apoptosis, Shuyu E

Theses and Dissertations (ETD)

Lysophosphatidic acid (LPA) is a naturally occurring lipid mediator. It exists abundantly in biological fluids such as serum, saliva, follicular fluid, seminal fluid and malignant effusions and induces a vast array of biological responses affecting cell growth, survival, differentiation, migration and morphology. We recently identified lysophosphatidic acid (LPA) as a potent antiapoptotic agent for the intestinal epithelium. Based on computational modeling octadecenyl thiophosphate (OTP) was synthesized: a novel rationally designed, metabolically stabilized LPA mimic. OTP was more efficacious than LPA in reducing g-irradiation-, camptothecin-, or TNF-a/cycloheximide-induced apoptosis and caspase 3, 8 and 9 activity in the IEC-6 cell line. The …

Upregulation Of Heme Oxygenase-1 Combined With Increased Adiponectin Lowers Blood Pressure In Diabetic Spontaneously Hypertensive Rats Through A Reduction In Endothelial Cell Dysfunction, Apoptosis And Oxidative Stress, Jian Cao, George Drummond, Kazuyoshi Inoue, Komal Sodhi, Xiao Ying Li, Shinji Omura

Pharmaceutical Science and Research

This study was designed to investigate the effect of increased levels of HO-1 on hypertension exacerbated by diabetes. Diabetic spontaneously hypertensive rat (SHR) and WKY (control) animals were treated with streptozotocin (STZ) to induce diabetes and stannous chloride (SnCl2) to upregulate HO-1. Treatment with SnCl2 not only attenuated the increase of blood pressure (p<0.01), but also increased HO-1 protein content, HO activity and plasma adiponectin levels, decreased the levels of superoxide and 3-nitrotyrosine (NT), respectively. Reduction in oxidative stress resulted in the increased expression of Bcl-2 and AKT with a concomitant reduction in circulating endothelial cells (CEC) in the peripheral blood (p<0.005) and an improvement of femoral reactivity (response to acetylcholine). Thus induction of HO-1 accompanied with increased plasma adiponectin levels in diabetic hypertensive rats alters the phenotype through a reduction in oxidative stress, thereby permitting endothelial cells to maintain an anti-apoptotic environment and the restoration of endothelial responses thus preventing hypertension.

Focal Cerebral Ischemia In The Tnfalpha-Transgenic Rat, L. Creed Pettigrew, Mark S. Kindy, Stephen W. Scheff, Joe E. Springer, Richard J. Kryscio, Yizhao Li, David S. Grass

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: To determine if chronic elevation of the inflammatory cytokine, tumor necrosis factor-alpha (TNFalpha), will affect infarct volume or cortical perfusion after focal cerebral ischemia.

METHODS: Transgenic (TNFalpha-Tg) rats overexpressing the murine TNFalpha gene in brain were prepared by injection of mouse DNA into rat oocytes. Brain levels of TNFalpha mRNA and protein were measured and compared between TNFalpha-Tg and non-transgenic (non-Tg) littermates. Mean infarct volume was calculated 24 hours or 7 days after one hour of reversible middle cerebral artery occlusion (MCAO). Cortical perfusion was monitored by laser-Doppler flowmetry (LDF) during MCAO. Cortical vascular density was quantified by stereology. …

The Aryl Hydrocarbon Receptor Binds To E2f1 And Inhibits E2f1-Induced Apoptosis., Jennifer L Marlowe, Yunxia Fan, Xiaoqing Chang, Li Peng, Erik S Knudsen, Ying Xia, Alvaro Puga

Kimmel Cancer Center Faculty Papers

Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr(-/-) fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, gammaH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of …

Nanosecond Pulsed Electric Fields Induce A Mitochondria-Independent Apoptosis In B16f10 Melanoma Cells In Vitro, Wentia Elissa Ford

Theses and Dissertations in Biomedical Sciences

Nanosecond pulsed electric fields (nsPEFs) are ultra-short pulses that induce direct electric field and biological effects that initiate apoptosis. Here the application of ten 300ns pulses ranging in electric fields from 12kV/cm-60kV/cm was administered to determine the effects on B16F10 melanoma cells evaluated by in vitro studies. Initial application of nsPEFs demonstrated apoptosis induction in an electric field- and pulse number-dependent manner measured by caspase activation that correlated with decrease in cell viability 24hr post pulse. In addition caspase activity was shown to be independent of calcium mobilization though ions may play a part in other aspects of apoptosis. The …

Enterotoxin Preconditioning Restores Calcium-Sensing Receptor-Mediated Cytostasis In Colon Cancer Cells, Giovanni Mario Pitari, Jieru E. Lin, Fawad J. Shah, Wilhelm J. Lubbe, David Zuzga, Peng Li, Stephanie Schulz, Scott A Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Guanylyl cyclase C (GCC), the receptor for diarrheagenic bacterial heat-stable enterotoxins (STs), inhibits colorectal cancer cell proliferation by co-opting Ca(2+) as the intracellular messenger. Similarly, extracellular Ca(2+) (Ca(2+)(o)) opposes proliferation and induces terminal differentiation in intestinal epithelial cells. In that context, human colon cancer cells develop a phenotype characterized by insensitivity to cytostasis imposed by Ca(2+)(o). Here, preconditioning with ST, mediated by GCC signaling through cyclic nucleotide-gated channels, restored Ca(2+)(o)-dependent cytostasis, reflecting posttranscriptional regulation of calcium-sensing receptors (CaRs). ST-induced GCC signaling deployed CaRs to the surface of human colon cancer cells, whereas elimination of GCC signaling in mice nearly abolished …

Nadph Oxidase In Pc12 Cell Differentiation And Apoptosis, Lina Begdache

Health & Wellness Studies Faculty Scholarship

Neuronal differentiation is an important process during human development and regenerative medicine. One factor linked to differentiation of neurons in vivo as well as in vitro is the generation of reactive oxygen species (ROS). In addition, neurodegeneration is the disease of the old age that is currently affecting millions. Although the etiology of each neurodegenerative disease differs, oxidative stress has been the common factor leading to neuronal death. PC12 cells differentiate into sympathetic-like neurons in the presence of nerve growth factor (NGF). Once terminally differentiated, PC12 cells undergo apoptosis following NGF deprivation with similar characteristics of sympathetic neuronal death. These …

The N-Terminal Domain Of The Y-Box Binding Protein Yb-1 Plays A Major Role In Cell Proliferation And Apoptosis, Payal Khandelwal

Theses and Dissertations (ETD)

Y-box binding protein, YB-1, is a member of the cold shock domain superfamily of proteins. It is involved in a plethora of cellular functions, including cell proliferation. The molecular mechanisms governing the involvement of YB-1 in cell proliferation are still unclear. Earlier studies done in chicken pre-B lymphocyte DT-40 cells in our laboratory have shown that a targeted disruption in one allele of chicken YB-1

(Chk-Yb-1b) gene at its N-terminal domain resulted in multiple abnormalities in the heterozygous mutants, including slower growth rate, abnormal cell morphology, increased cell size, increased genomic DNA content and significant changes in levels of cell …

Ly2109761, A Novel Transforming Growth Factor Beta Receptor Type I And Type Ii Dual Inhibitor, As A Therapeutic Approach To Suppressing Pancreatic Cancer Metastasis., Davide Melisi, Satoshi Ishiyama, Guido M Sclabas, Jason B Fleming, Qianghua Xia, Giampaolo Tortora, James L Abbruzzese, Paul J Chiao

Journal Articles

Most pancreatic cancer patients present with inoperable disease or develop metastases after surgery. Conventional therapies are usually ineffective in treating metastatic disease. It is evident that novel therapies remain to be developed. Transforming growth factor beta (TGF-beta) plays a key role in cancer metastasis, signaling through the TGF-beta type I/II receptors (TbetaRI/II). We hypothesized that targeting TbetaRI/II kinase activity with the novel inhibitor LY2109761 would suppress pancreatic cancer metastatic processes. The effect of LY2109761 has been evaluated on soft agar growth, migration, invasion using a fibroblast coculture model, and detachment-induced apoptosis (anoikis) by Annexin V flow cytometric analysis. The efficacy …

Trail Mediates Liver Injury By The Innate Immune System In The Bile Duct-Ligated Mouse., Alisan Kahraman, Fernando J. Barreyro, Steven F. Bronk, Nathan W. Werneburg, Justin L. Mott, Yuko Akazawa, Howard C Masuoka, Charles L Howe, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

The contribution of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a death ligand expressed by cells of the innate immune system, to cholestatic liver injury has not been explored. Our aim was to ascertain if TRAIL contributes to liver injury in the bile duct-ligated (BDL) mouse. C57/BL6 wild-type (wt), TRAIL heterozygote (TRAIL(+/-)), and TRAIL knockout (TRAIL(-/-)) mice were used for these studies. Liver injury and fibrosis were examined 7 and 14 days after BDL, respectively. Hepatic TRAIL messenger RNA (mRNA) was 6-fold greater in BDL animals versus sham-operated wt animals (P < 0.01). The increased hepatic TRAIL expression was accompanied by an increase in liver accumulation of natural killer 1.1 (NK 1.1)-positive NK and natural killer T (NKT) cells, the predominant cell types expressing TRAIL. Depletion of NK 1.1-positive cells reduced hepatic TRAIL mRNA expression and serum alanine aminotransferase (ALT) values. Consistent with a role for NK/NKT cells in this model of liver injury, stress ligands necessary for their recognition of target cells were also up-regulated in hepatocytes following BDL. Compared to sham-operated wt mice, BDL mice displayed a 13-fold increase in terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and an 11-fold increase in caspase 3/7-positive hepatocytes (P < 0.01). The number of TUNEL and caspase 3/7-positive cells was reduced by >80% in BDL TRAIL knockout animals (P < 0.05). Likewise, liver histology, number of bile infarcts, serum ALT values, hepatic fibrosis, and animal survival were also improved in BDL TRAIL(-/-) animals as compared to wt animals. Conclusion: These observations support a pivotal role for TRAIL in cholestatic liver injury mediated by NK 1.1-positive NK/NKT cells.

Retinoic Acid Decreases Atf-2 Phosphorylation And Sensitizes Melanoma Cells To Taxol-Mediated Growth Inhibition, Ying Huang, Jennifer Minigh, Sarah Miles, Richard N. Niles

Biochemistry and Microbiology

Cutaneous melanoma is often resistant to chemo- and radiotherapy. This resistance has recently been demonstrated to be due, at least in part, to high activating transcription factor 2 (ATF-2) activity in these tumors. In concordance with these reports, we found that B16 mouse melanoma cells had higher levels of ATF-2 than immortalized, but non-malignant mouse melanocytes. In addition, the melanoma cells had a much higher amount of phosphorylated (active) ATF-2 than the immortalized melanocytes. In the course of determining how retinoic acid (RA) stimulates activating protein-1 (AP-1) activity in B16 melanoma, we discovered that this retinoid decreased the phosphorylation of …

Introducing Point Mutations Into The Atgs Of The Putative Open Reading Frames Of The Hsv-1 Gene Encoding The Latency Associated Transcript (Lat) Reduces Its Anti-Apoptosis Activity, Dale Carpenter, Gail A. Henderson, Chinhui Hsiang, Nelson Osorio, Lbachir Benmohamed, Clinton J. Jones, S L. Wechsler

School of Veterinary and Biomedical Sciences: Faculty Publications

The herpes simplex virus type 1 (HSV-1) latency associated transcript (LAT) gene has anti-apoptosis activity that directly or indirectly enhances the virus’s reactivation phenotype in small animal models. The first 1.5 kb of the primary 8.3 kb LAT is sufficient and some or all of it is necessary for LAT’s anti-apoptosis in transient transfection assays and for LAT’s ability to enhance the reactivation phenotype. Based on LAT’s genomic sequence, the first 1.5 kb contains eight potential open reading frames (ORFs) defined as an ATG followed by an in frame termination codon. In this study, point mutations were introduced into the …

Genome-Wide Expression Profiling Reveals Transcriptomic Variation And Perturbed Gene Networks In Androgen-Dependent And Androgen-Independent Prostate Cancer Cells., Ajay P. Singh, Sangeeta Bafna, Kunal Chaudhary, Ganesh Venkatraman, Lynette Smith, James D. Eudy, Sonny L. Johansson, Ming-Fong Lin, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Previously, we have developed a unique in vitro LNCaP cell model, which includes androgen-dependent (LNCaP-C33), androgen-independent (LNCaP-C81) and an intermediate phenotype (LNCaP-C51) cell lines resembling the stages of prostate cancer progression to hormone independence. This model is advantageous in overcoming the heterogeneity associated with the prostate cancer up to a certain extent. We characterized and compared the gene expression profiles in LNCaP-C33 (androgen-dependent) and LNCaP-C81 (androgen-independent) cells using Affymetrix GeneChip array analyses. Multiple genes were identified exhibiting differential expression during androgen-independent progression. Among the important genes upregulated in androgen-independent cells were PCDH7, TPTE, TSPY, EPHA3, HGF, MET, EGF, TEM8, etc., …

Bovine Herpesvirus Type 1 Induces Cell Death By A Cell Type Dependent Fashion, Vicki Geiser, Suzanne Rose, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Bovine herpesvirus 1 (BHV-1), a member of the alpha-herpesvirinae subfamily, causes significant losses to the cattle industry. BHV-1 establishes latency in trigeminal ganglionic sensory neurons, but periodically reactivates from latency. Previous studies suggested that infection with BHV-1 induced novel morphological changes in rabbit skin cells (RS) versus bovine kidney cells (MDBK). Consequently, we hypothesized that viral infection led to a novel form of cell death in RS cells compared to MDBK cells. To test this hypothesis, we examined the levels of apoptosis in these cell types following infection with BHV-1. Infection of RS, but not MDBK, cells leads to high …

Adhesion Of Beta1 Integrin To Fibronectin Regulates Cam-Dr Phenotype Via P21^{Waf1/Cip1} In Hl60 Acute Myeloid Leukemia (Aml) Cells, Hande Canpinar, Güneş Esendağli, Emi̇n Kansu, Aysen Günel Özcan, Di̇cle Güç

Turkish Journal of Medical Sciences

Aims: Drug resistance is a major obstacle for a successful cancer therapy. Cell adhesion mediated drug resistance (CAM-DR) is a novel type of drug resistance and generated via interaction of cancer cells with the microenvironment. In this study, CAM-DR phenotype was analyzed in HL60 acute myeloid leukemia (AML) cells. Materials and Methods: Fibronectin (FN) adherence of HL60 cells was tested by a colorimetric adhesion assay. Flow cytometry analyses were performed to evaluate doxorubicin-induced apoptosis and to determine cell cycle status. Proliferation rate was evaluated by [^3H]-thymidine incorporation assay. Western blot and RT-PCR were used for analysis of the factors involved …

Inhibition Of Oncogene-Induced Inflammatory Chemokines Using A Farnesyltransferase Inhibitor., Katharine C Degeorge, Brent R Degeorge, James S Testa, Jay L Rothstein

Department of Microbiology and Immunology Faculty Papers

ABSTRACT: BACKGROUND: Farnesyltransferase inhibitors (FTI) are small molecule agents originally formulated to inhibit the oncogenic functions of Ras. Although subsequent analysis of FTI activity revealed wider effects on other pathways, the drug has been demonstrated to reduce Ras signaling by direct measurements. The purpose of the current study was to determine if FTI could be used to inhibit the inflammatory activities of a known Ras-activating human oncoprotein, RET/PTC3. RET/PTC3 is a fusion oncoprotein expressed in the thyroid epithelium of patients afflicted with thyroid autoimmune disease and/or differentiated thyroid carcinoma. Previous studies have demonstrated that RET/PTC3 signals through Ras and can …