ABSTRACT
Viral infections are particularly common after cardiac transplantation. Herein we have presented a case of Epstein-Barr infection that presented as a viral syndrome with respiratory symptoms, but was complicated by multiorgan failure and disseminated intravascular coagulation. Transplant physicians should be aware of this unique complication of an otherwise self-limited infection.
Subject(s)
Disseminated Intravascular Coagulation/pathology , Epstein-Barr Virus Infections/complications , Heart Transplantation/methods , Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Creatinine/blood , Disseminated Intravascular Coagulation/complications , Follow-Up Studies , Humans , Male , Middle Aged , Myocardial Ischemia/surgery , Reoperation/methods , Treatment OutcomeABSTRACT
The interface between apoptosis (programmed cell death) and the cell cycle is essential to preserve homeostasis and genomic integrity. Here, we show that survivin, an inhibitor of apoptosis over-expressed in cancer, physically associates with the cyclin-dependent kinase p34(cdc2) on the mitotic apparatus, and is phosphorylated on Thr(34) by p34(cdc2)-cyclin B1, in vitro and in vivo. Loss of phosphorylation on Thr(34) resulted in dissociation of a survivin-caspase-9 complex on the mitotic apparatus, and caspase-9-dependent apoptosis of cells traversing mitosis. These data identify survivin as a mitotic substrate of p34(cdc2)-cyclin B1 and suggest that survivin phosphorylation on Thr(34) may be required to preserve cell viability at cell division. Manipulation of this pathway may facilitate the elimination of cancer cells at mitosis.
Subject(s)
Apoptosis/physiology , CDC2 Protein Kinase/metabolism , Cell Division/physiology , Microtubule-Associated Proteins , Proteins/chemistry , Proteins/metabolism , Amino Acid Sequence , Antibodies , Cell Cycle/physiology , HeLa Cells , Humans , Inhibitor of Apoptosis Proteins , Kinetics , Melanoma , Molecular Sequence Data , Mutagenesis, Site-Directed , Neoplasm Proteins , Peptide Fragments/chemistry , Peptide Fragments/immunology , Peptide Fragments/metabolism , Phosphorylation , Proteins/genetics , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Survivin , Transfection , Tumor Cells, CulturedABSTRACT
The activity of endothelial nitric-oxide synthase (eNOS) is regulated by its subcellular localization, phosphorylation and through its interaction with different proteins. The association of eNOS with caveolin-1 (Cav) is believed to maintain eNOS in an inactive state; however, increased association of eNOS to heat shock protein 90 (hsp90) is observed following activation. In this study, we investigate the relationship between caveolin and hsp90 as opposing regulatory proteins on eNOS function. Immunoprecipitation of Cav-1 from bovine lung microvascular endothelial cells shows that eNOS and hsp90 are present in the Cav-1 complex. eNOS and hsp90 from the lysate also interact with exogenous glutathione S-transferase-linked caveolin-1 (GST-Cav), and the addition of calcium-activated calmodulin (CaM) to the GST-Cav complex partially inhibited the association of eNOS and hsp90. Purified eNOS associates with GST-Cav specifically through the caveolin-scaffolding domain (residues 82-101); however, the addition of CaM slightly, but nonstatistically, reduces eNOS binding to GST-Cav. When hsp90 is present in the binding reaction, the addition of increasing concentrations of CaM significantly displaces eNOS and hsp90 from GST-Cav. eNOS enzymatic activity is also less sensitive to inhibition by the caveolin scaffolding peptide (residues 82-101) when eNOS is prebound to hsp90. Collectively, our results show that the actions of CaM on eNOS dissociation from caveolin are facilitated in the presence of hsp90.
Subject(s)
Caveolins , Endothelium, Vascular/metabolism , HSP90 Heat-Shock Proteins/metabolism , Membrane Proteins/metabolism , Nitric Oxide Synthase/metabolism , Animals , Biological Transport , Calmodulin/metabolism , Cattle , Caveolin 1 , Cells, Cultured , Enzyme Activation , Nitric Oxide Synthase Type III , PhosphorylationABSTRACT
A productive angiogenic response must couple to the survival machinery of endothelial cells to preserve the integrity of newly formed vessels. Angiopoietin-1 (Ang-1) is an endothelium-specific ligand essential for embryonic vascular stabilization, branching morphogenesis, and post-natal angiogenesis, but its contribution to endothelial cell survival has not been completely elucidated. Here we show that Ang-1 acting via the Tie 2 receptor induces phosphorylation of the survival serine-threonine kinase, Akt (or protein kinase B). This is associated with up-regulation of the apoptosis inhibitor, survivin, in endothelial cells and protection of endothelium from death-inducing stimuli. Moreover, dominant negative survivin negates the ability of Ang-1 to protect cells from undergoing apoptosis. The activation of anti-apoptotic pathways mediated by Akt and survivin in endothelial cells may contribute to Ang-1 stabilization of vascular structures during angiogenesis, in vivo.
Subject(s)
Apoptosis/drug effects , Endothelium, Vascular/drug effects , Membrane Glycoproteins/pharmacology , Microtubule-Associated Proteins , Protein Serine-Threonine Kinases , Proteins/metabolism , Proto-Oncogene Proteins/metabolism , Angiopoietin-1 , Animals , Cattle , Cells, Cultured , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Flow Cytometry , Inhibitor of Apoptosis Proteins , Neoplasm Proteins , Phosphorylation , Proto-Oncogene Proteins c-akt , SurvivinABSTRACT
Mechanisms controlling endothelial cell survival during angiogenesis were investigated. Stimulation of quiescent endothelial cells with mitogens, including vascular endothelial growth factor and basic fibroblast growth factor, induced up to approximately 16-fold up-regulation of the cell cycle-regulated apoptosis inhibitor survivin. Mitogen stimulation rapidly increased survivin RNA expression in endothelial cells, which peaked after 6 to 10 hours in culture and decreased by 24 hours. Inflammatory cytokines, tumor necrosis factor alpha, and interleukin-1 did not induce survivin expression in endothelial cells. Formation of three-dimensional vascular tubes in vitro was associated with strong induction of survivin in endothelial cells, as compared with two-dimensional cultures. By immunohistochemistry, survivin was minimally expressed in endothelium of nonproliferating capillaries of normal skin, whereas it became massively up-regulated in newly formed blood vessels of granulation tissue in vivo. Recombinant expression of green fluorescent protein survivin in endothelial cells reduced caspase-3 activity and counteracted apoptosis induced by tumor necrosis factor alpha/cycloheximide. These findings identify survivin as a novel growth factor-inducible protective gene expressed by endothelial cells during angiogenesis. Therapeutic manipulation of survivin expression and function in endothelium may influence compensatory or pathological (tumor) angiogenesis.
Subject(s)
Apoptosis/physiology , Endothelium, Vascular/physiology , Microtubule-Associated Proteins , Neovascularization, Physiologic/physiology , Proteins/metabolism , Apoptosis/drug effects , Cell Division/physiology , Cell Survival/drug effects , Cells, Cultured , Endothelial Growth Factors/pharmacology , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Fibroblast Growth Factor 2/pharmacology , Humans , Inhibitor of Apoptosis Proteins , Lymphokines/pharmacology , Mitogens/pharmacology , Neoplasm Proteins , Proteins/pharmacology , Survivin , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth FactorsABSTRACT
Adenosquamous carcinoma of the pancreas is an unusual tumor. The authors review the case report of a 70-year-old male. Radiologic and computer tomography (CT) findings for adenosquamous carcinoma were indistinguishable from adenocarcinoma of the pancreas.
Subject(s)
Adenocarcinoma , Carcinoma, Squamous Cell , Pancreatic Neoplasms , Adenocarcinoma/diagnostic imaging , Adenocarcinoma/therapy , Aged , Carcinoma, Squamous Cell/diagnostic imaging , Carcinoma, Squamous Cell/therapy , Humans , Male , Pancreatic Neoplasms/diagnostic imaging , RadiographyABSTRACT
In West Virginia from 1959 to 1975 there were 279 deaths caused by malignant melanoma. From 1959 to 1967 there were 8.4 such deaths per year and from 1968 to 1975, 25.4 per year (2P < .0005). This trend was observed throughout the state. The population-adjusted melanoma mortality of 1.45 per 100,000 from 1968 to 1975 contrasts with a rate of only 0.48 per 100,000 during the earlier period from 1959 to 1967. The rate of increase was greater in the southern portion of the state. The highest melanoma mortality was seen in the state's major agricultural area, while the lowest rate was seen in its most densely populated urban region. In our community, 102 new melanoma cases were diagnosed from 1969 to 1978. From 1969 to 1973, there were 33 new cases, 6.6 per year, and from 1974 to 1978, 13.8 per year (2P < .01). Men tended to be older at the time of diagnosis. The most common locations of the primary tumors were the lower extremity in women and the trunk and head and neck in men.
