Medicine and Health Sciences Commons^™

C-Jun N-Terminal Kinase (Jnk) Is Required For Survival And Proliferation Of B-Lymphoma Cells, Murali Gururajan, Roger Chui, Anbu K. Karuppannan, Jiyuan Ke, C. Darrell Jennings, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Several primary murine and human B lymphomas and cell lines were found to constitutively express high levels of the activated form of c-jun N-terminal kinase (JNK), a member of the mitogen-activated protein (MAP) kinase family. Proliferation of murine B lymphomas CH31, CH12.Lx, BKS-2, and WEHI-231 and the human B lymphomas BJAB, RAMOS, RAJI, OCI-Ly7, and OCI-Ly10 was strongly inhibited by SP600125, an anthrapyrazolone inhibitor of JNK, in a dose-dependent manner. The lymphoma cells underwent apoptosis and arrested at the G2/M phase of cell cycle. Furthermore, JNK-specific small interfering RNA (siRNA) inhibited the growth of both murine and human B lymphomas. …

Evaluation Of Glucocorticoid Sensitivity In 697 Pre-B Acute Lymphoblastic Leukemia Cells After Overexpression Or Silencing Of Map Kinase Phosphotase-1, Marc T. Abrams, Noreen Robertson, Gerald Litwack, Eric Wickstrom

Department of Biochemistry and Molecular Biology Faculty Papers

PURPOSE: To determine the effect of reducing MAP kinase phosphatase-1 (MKP-1) levels on cell death induced by glucocorticoid (GC) or hydroxyurea (HU) treatment in the human pre-B acute lymphoblastic leukemia cell line 697.

METHODS: Stable MKP-1 overexpressing transformants of the 697 pre-B ALL cell line were created and tested for sensitivity to the GC triamcinolone acetonide (TA) and HU, and compared to a control 697 cell line containing normal MKP-1 expression levels. Small interfering RNAs (siRNAs) were designed to inhibit MKP-1 expression and evaluated for their effect on GC-mediated cell death.

RESULTS: MKP-1 overexpression caused a phenotype of partial resistance …

Multiple Metabolic Hits Converge On Cd36 As Novel Mediator Of Tubular Epithelial Apoptosis In Diabetic Nephropathy., Katalin Susztak, Emilio Ciccone, Peter Mccue, Kumar Sharma, Erwin P Böttinger

Department of Medicine Faculty Papers

BACKGROUND: Diabetic nephropathy (DNP) is a common complication of type 1 and type 2 diabetes mellitus and the most common cause of kidney failure. While DNP manifests with albuminuria and diabetic glomerulopathy, its progression correlates best with tubular epithelial degeneration (TED) and interstitial fibrosis. However, mechanisms leading to TED in DNP remain poorly understood.

METHODS AND FINDINGS: We found that expression of scavenger receptor CD36 coincided with proximal tubular epithelial cell (PTEC) apoptosis and TED specifically in human DNP. High glucose stimulated cell surface expression of CD36 in PTECs. CD36 expression was necessary and sufficient to mediate PTEC apoptosis induced …

Mitochondrial Dna Mutations, Apoptosis, And The Misfolded Protein Response., Justin L. Mott, Dekui Zhang, Hans Peter Zassenhaus

Journal Articles: Biochemistry & Molecular Biology

Studies of transgenic mice with accelerated accumulation of mtDNA mutations specifically in the heart lead us to propose that apoptotic signaling and cell death is central to the pathogenesis of mtDNA mutations in aging. It is the cellular response to that apoptotic signaling and the organ?s compensatory response to a loss of cells that specify the phenotype of an accumulation of mtDNA mutations. In the heart, cardiomyocytes induce a vigorous anti-apoptotic, pro-survival response to counteract mitochondrial apoptotic signaling. The heart up-regulates contractility of remaining myocytes in order to maintain cardiac output. We hypothesize that mutant mitochondrial proteins originate apoptotic signaling …

Inhibition Of Glucocorticoid-Induced Apoptosis By Targeting Splice Variants Of Bim Mrna With Small Interfering Rna And Short Hairpin Rna., Marc T. Abrams, Noreen M. Robertson, Kyonggeun Yoon, Eric Wickstrom

Department of Biochemistry and Molecular Biology Faculty Papers

Glucocorticoids (GCs) induce apoptosis in lymphocytes and are effective agents for the treatment of leukemia. The activated glucocorticoid receptor (GR) initiates a transcriptional program leading to caspase activation and cell death, but the critical signaling intermediates in GC-induced apoptosis remain largely undefined. We have observed that GC induction of the three major protein products of the Bcl-2 relative Bim (BimEL, BimS and BimL) correlates with GC sensitivity in a panel of human pre-B acute lymphoblastic leukemia (ALL) cell lines. To test the hypothesis that Bim facilitates GC-induced apoptosis, we reduced BIM mRNA levels and Bim protein levels by RNA interference …

Gitr Activation Induces An Opposite Effect On Alloreactive Cd4(+) And Cd8(+) T Cells In Graft-Versus-Host Disease., Stephanie J Muriglan, Teresa Ramirez-Montagut, Onder Alpdogan, Thomas W Van Huystee, Jeffrey M Eng, Vanessa M Hubbard, Adam A Kochman, Kartono H Tjoe, Carlo Riccardi, Pier Paolo Pandolfi, Shimon Sakaguchi, Alan N Houghton, Marcel R M Van Den Brink

Department of Medical Oncology Faculty Papers

Glucocorticoid-induced tumor necrosis factor receptor family-related gene (GITR) is a member of the tumor necrosis factor receptor (TNFR) family that is expressed at low levels on unstimulated T cells, B cells, and macrophages. Upon activation, CD4(+) and CD8(+) T cells up-regulate GITR expression, whereas immunoregulatory T cells constitutively express high levels of GITR. Here, we show that GITR may regulate alloreactive responses during graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT). Using a BMT model with major histocompatibility complex class I and class II disparity, we demonstrate that GITR stimulation in vitro and in vivo enhances alloreactive CD8(+)CD25(-) T …

The Tumor Suppressor Lkb1 Kinase Directly Activates Amp-Activated Kinase And Regulates Apoptosis In Response To Energy Stress, Reuben J. Shaw, Monica Kosmatka, Nabeel Bardeesy, Rebecca L. Hurley, Lee A. Witters, Ronald A. Depinho, Lewis C. Cantley

Dartmouth Scholarship

AMP-activated protein kinase (AMPK) is a highly conserved sensor of cellular energy status found in all eukaryotic cells. AMPK is activated by stimuli that increase the cellular AMP/ATP ratio. Essential to activation of AMPK is its phosphorylation at Thr-172 by an upstream kinase, AMPKK, whose identity in mammalian cells has remained elusive. Here we present biochemical and genetic evidence indicating that the LKB1 serine/threonine kinase, the gene inactivated in the Peutz-Jeghers familial cancer syndrome, is the dominant regulator of AMPK activation in several mammalian cell types. We show that LKB1 directly phosphorylates Thr-172 of AMPKalpha in vitro and activates its …

Toxoplasma Gondii Induces Granulocyte Colony-Stimulating Factor And Granulocyte-Macrophage Colony-Stimulating Factor Secretion By Human Fibroblasts: Implications For Neutrophil Apoptosis, Jacqueline Y. Channon, Kristin A. Miselis, Laurie A. Minns, Chaitali Dutta, Lloyd H. Kasper

Dartmouth Scholarship

Human neutrophils are rescued from apoptosis following incubation with once-washed, fibroblast-derived Toxoplasma gondii tachyzoites. Both infected and uninfected neutrophils are rescued, implicating a soluble mediator. In this study we investigated the origin and identity of this soluble mediator. Neutrophils were incubated either with purified tachyzoites or with conditioned medium derived from T. gondii-infected human fibroblasts. Conditioned medium was found to be a potent stimulus that delayed neutrophil apoptosis up to 72 h, whereas purified and extensively washed tachyzoites had no effect. Delayed apoptosis correlated with up-regulation of the neutrophil antiapoptotic protein, Mcl-1, and the neutrophil interleukin 3 receptor alpha subunit …

Method For Controlling Cell Necrosis Or Apoptosis, Elaine L. Jacobson, Myron Jacobson

Graduate Center for Nutritional Sciences Faculty Patents

The invention relates to the manipulation of enzymatic pathways, such as poly (ADP-ribose) polymerase pathways, which are dependent upon NAD as a substrate. By administering pro-NAD compounds, cell death caused by necrosis and/or apoptosis can be reduced. Further, by inhibiting one or more of these enzymes, the process of cell death can be accelerated, in conditions such as cancer, where acceleration of cellular necrosis and/or apoptosis is desired. Various inhibitors are described.

Ube1l Is A Retinoid Target That Triggers Pml/Rarα Degradation And Apoptosis In Acute Promyelocytic Leukemia, Sutisak Kitareewan, Ian Pitha-Rowe, David Sekula, Christopher H. Lowrey, Michael J. Nemeth, Todd R. Golub, Sarah J. Freemantle, Ethan Dmitrovsky

Dartmouth Scholarship

All-trans-retinoic acid (RA) treatment induces remissions in acute promyelocytic leukemia (APL) cases expressing the t(15;17) product, promyelocytic leukemia (PML)/RA receptor α (RARα). Microarray analyses previously revealed induction of UBE1L (ubiquitin-activating enzyme E1-like) after RA treatment of NB4 APL cells. We report here that this occurs within 3 h in RA-sensitive but not RA-resistant APL cells, implicating UBE1L as a direct retinoid target. A 1.3-kb fragment of the UBE1L promoter was capable of mediating transcriptional response to RA in a retinoid receptor-selective manner. PML/RARα, a repressor of RA target genes, abolished this UBE1L promoter activity. A hallmark of …

Siva-1 Binds To And Inhibits Bcl-Xl-Mediated Protection Against Uv Radiation-Induced Apoptosis, Li Xue, Fei Chu, Yuan Cheng, Xiangjie Sun, Alip Borthakur, Manjunath Ramarao, Pramod Pandey, Mei Wu, Stuart F. Schlossman, Kanteti V. S. Prasad

Clinical & Translational Sciences

We previously cloned Siva-1 by using the cytoplasmic tail of CD27, a member of the tumor necrosis factor receptor family, as the bait in the yeast two-hybrid system. The Siva gene is organized into four exons that code for the predominant full-length Siva-1 transcript, whereas its alternate splice form, Siva-2, lacks exon 2 coding sequence. Various groups have demonstrated a role for Siva-1 in several apoptotic pathways. Interestingly, the proapoptotic properties of Siva-1 are lacking in Siva-2. The fact that Siva-1 is partly localized to mitochondria despite the absence of any mitochondrial targeting signal, it harbors a 20-aa-long putative amphipathic …

Vdac-Dependent Permeabilization Of The Outer Mitochondrial Membrane By Superoxide Induces Rapid And Massive Cytochrome C Release., M Madesh, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Enhanced formation of reactive oxygen species (ROS), superoxide (O2*-), and hydrogen peroxide (H2O2) may result in either apoptosis or other forms of cell death. Here, we studied the mechanisms underlying activation of the apoptotic machinery by ROS. Exposure of permeabilized HepG2 cells to O2*- elicited rapid and massive cytochrome c release (CCR), whereas H2O2 failed to induce any release. Both O2*- and H2O2 promoted activation of the mitochondrial permeability transition pore by Ca2+, but Ca2+-dependent pore opening was not required for O2*--induced CCR. Furthermore, O2*- alone evoked CCR without damage of the inner mitochondrial membrane barrier, as mitochondrial membrane potential …

Immunologic Effects Of Gliotoxin In Rats: Mechanisms For Prevention Of Autoimmune Diabetes Mellitus, Honggang Liu, Susan H. Jackman, Henry Driscoll, Bryan Larsen

Biochemistry and Microbiology

Various fungal products, such as gliotoxin (GT), have immunomodulating activity, a fact exploited previously by our group for prevention of autoimmune diabetes mellitus in BB/Wor rats. To understand better the immunologic effects in GT-treated rats, splenocytes from 65-day-old prediabetic diabetes-prone rats were phenotypically characterized after chronic treatment with GT. A parallel study examined the direct effects of GT on splenocyte preparations incubated with the mycotoxin. In vitro treatment of splenocytes with GT revealed relative decreases in CD4+ and increases in CD8+ T-cell subsets, whereas in vivo treatment with GT did not result in detectable alterations in relative CD4+ and CD8+ …

Signal Transducer And Activator Of Transcription (Stat)5 Activation By Bcr/Abl Is Dependent On Intact Src Homology (Sh)3 And Sh2 Domains Of Bcr/Abl And Is Required For Leukemogenesis., M Nieborowska-Skorska, M A Wasik, A Slupianek, P Salomoni, T Kitamura, B Calabretta, T Skorski

Department of Microbiology and Immunology Faculty Papers

Signal transducer and activator of transcription (STAT)5 is constitutively activated in BCR/ ABL-expressing cells, but the mechanisms and functional consequences of such activation are unknown. We show here that BCR/ABL induces phosphorylation and activation of STAT5 by a mechanism that requires the BCR/ABL Src homology (SH)2 domain and the proline-rich binding site of the SH3 domain. Upon expression in 32Dcl3 growth factor-dependent myeloid precursor cells, STAT5 activation-deficient BCR/ABL SH3+SH2 domain mutants functioned as tyrosine kinase and activated Ras, but failed to protect from apoptosis induced by withdrawal of interleukin 3 and/or serum and did not induce leukemia in severe combined …

Expression Of Constitutively Active Raf-1 In The Mitochondria Restores Antiapoptotic And Leukemogenic Potential Of A Transformation-Deficient Bcr/Abl Mutant., P Salomoni, M A Wasik, R F Riedel, K Reiss, J K Choi, T Skorski, B Calabretta

Department of Microbiology and Immunology Faculty Papers

The oncogenic BCR/ABL protein protects hematopoietic cells from apoptosis induced by growth factor deprivation, but the mechanisms are only partially understood. A BCR/ABL mutant lacking amino acids 176-426 in the BCR domain (p185DeltaBCR) failed to protect interleukin 3-deprived 32Dcl3 myeloid precursor cells from apoptosis, although it possessed tyrosine kinase activity and was capable of activating the Ras-Raf-MAP kinase pathway. Compared to p185 wild-type transfectants, p185DeltaBCR-transfected cells showed markedly reduced levels of Bcl-2 and expressed the hypophosphorylated, proapoptotic form of BAD. Bcl-2 expression in the mitochondrial fraction of p185DeltaBCR cells was also markedly diminished and mitochondrial RAF was undetectable. In p185DeltaBCR …

Role Of Egr-1 Gene Expression In B Cell Receptor-Induced Apoptosis In An Immature B Cell Lymphoma, Subramanian Muthukkumar, Seong-Su Han, Sumathi Muthukkumar, Vivek M. Rangnekar, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Ligation of B cell receptor (BCR) on BKS-2, an immature B cell lymphoma by anti-IgM antibodies (Ab) caused apoptosis. Here we report that signaling through B cell receptor in wild type BKS-2 cells down-regulated the expression of Egr-1, a zinc finger-containing transcription factor. A reduction in the level ofEgr-1 mRNA could be demonstrated as early as 30 min after the ligation of BCR on BKS-2 cells. Immunocytochemical and Western blot analysis revealed that the expression of EGR-1 protein was also inhibited by anti-IgM treatment. Antisense oligonucleotides to Egr-1 caused growth inhibition and apoptosis in BKS-2 cells, suggesting that …