RESUMO
The lysosomal endoprotease cathepsin D (CatD) is an essential player in general protein turnover and specific peptide processing. CatD-deficiency is associated with neurodegenerative diseases, whereas elevated CatD levels correlate with tumor malignancy and cancer cell survival. Here, we show that the CatD ortholog of the budding yeast Saccharomyces cerevisiae (Pep4p) harbors a dual cytoprotective function, composed of an anti-apoptotic part, conferred by its proteolytic capacity, and an anti-necrotic part, which resides in the protein's proteolytically inactive propeptide. Thus, deletion of PEP4 resulted in both apoptotic and necrotic cell death during chronological aging. Conversely, prolonged overexpression of Pep4p extended chronological lifespan specifically through the protein's anti-necrotic function. This function, which triggered histone hypoacetylation, was dependent on polyamine biosynthesis and was exerted via enhanced intracellular levels of putrescine, spermidine and its precursor S-adenosyl-methionine. Altogether, these data discriminate two pro-survival functions of yeast CatD and provide first insight into the physiological regulation of programmed necrosis in yeast.
Assuntos
Apoptose/genética , Ácido Aspártico Endopeptidases , Catepsina D/metabolismo , Lisossomos/metabolismo , Necrose/metabolismo , Precursores de Proteínas/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Acetilação , Ácido Aspártico Endopeptidases/biossíntese , Ácido Aspártico Endopeptidases/deficiência , Ácido Aspártico Endopeptidases/genética , Poliaminas Biogênicas/metabolismo , Catepsina D/genética , Sobrevivência Celular , Senescência Celular , Deleção de Genes , Expressão Gênica , Histonas/genética , Histonas/metabolismo , Lisossomos/genética , Necrose/genética , Plasmídeos , Engenharia de Proteínas/métodos , Precursores de Proteínas/genética , Estrutura Terciária de Proteína/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/biossíntese , Proteínas de Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos , TransfecçãoRESUMO
Calcified atherosclerotic lesions are more prone to rupture during angioplasty than non-calcified lesions and are associated with an increased risk of thrombotic complications following angioplasty. This study investigates the possible role of extracellular matrix (ECM) calcification for platelet adhesion. Human cultured fibroblasts (CRL-1635) were subjected to beta-glycerophosphate (10 mM) for 10 to 16 days. Calcification was visualized by von Kossa staining and quantified by the O-cresolphthalein complexone method. Adhesion of calcein-labelled platelets was measured by fluorescence microscopy at static conditions and in a parallel-flow chamber at a shear rate of 1000 s(-1). beta-glycerophosphate treatment resulted in a marked calcification of the ECM. In parallel, a small, albeit significant increase in platelet adhesion under static conditions was observed. In contrast, at flow conditions, the area covered by thrombi was significantly lower when calcified ECM was used. The number of thrombi was not significantly different which is compatible with a smaller thrombus size. Taken together, it appears unlikely that calcification of atherosclerotic lesions contributes to thrombotic complications by an increased platelet adhesion.
Assuntos
Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Adesividade Plaquetária/fisiologia , Apatitas/metabolismo , Plaquetas/citologia , Plaquetas/metabolismo , Calcificação Fisiológica/fisiologia , Cálcio/metabolismo , Técnicas de Cultura de Células , Linhagem Celular , Fibroblastos/efeitos dos fármacos , Glicerofosfatos/farmacologia , Humanos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Adesividade Plaquetária/efeitos dos fármacosRESUMO
In 895 patients operated on for acute appendicitis we found Yersinia enterocolitica in 41 cases. Another two cases were detected in postoperative serological examinations. Lymphadenitis mesenterialis was present in 17 cases during operation. Once we detected a regional enteritis. Histological examination of the appendix revealed a purulent inflammation in 21 cases and a phlegmonous-gangrenous inflammation in 4 cases. The other 18 patients suffered from Oxyuriasis, coprostasis or scars of the appendix. For this reason it is impossible to exclude an acute appendicitis in patients with cultural or serological identification of Yersinia enterocolitica.
Assuntos
Apendicite/microbiologia , Doença de Crohn/complicações , Linfadenite Mesentérica/complicações , Infecções por Pasteurella/complicações , Yersinia/isolamento & purificação , Doença Aguda , Animais , Berlim , Chinchila , Reservatórios de Doenças , Humanos , Coelhos , Estações do Ano , SuínosRESUMO
To estimate the germ-preserving effect of 15 percent disodium-calcium-ethylene-diamine-tetraacetate, 1.8 percent boric acid, 20 percent dimethyl sulfoxide and 3 solutions containing 0.001 percent merthiolate and 15 percent glycerin, 2 percent ethylene-diamine-tetraacetic acid and 15 percent glycerin, and 30 percent NaCl and 3 percent polyvinyl pyrrolidone respectively, comparative investigations were conducted in 4 series comprising a total of 400 urine samples. Boric acid, which is very easy to use, proved the most effective. After 24-h storage at room temperature of boric-acid-preserved urine samples with bacterial counts of over 10-4 per ml, the results were false-negative in 2-4 percent; after 48 h the rate was 6-8 percent and after 72 h nearly 10 percent. There were no false-positive results.
