Assuntos
Carcinoma Basocelular/genética , Predisposição Genética para Doença , Melanoma/genética , Neoplasias Cutâneas/genética , Idoso , Biópsia , Carcinoma Basocelular/complicações , Carcinoma Basocelular/patologia , Seguimentos , Marcadores Genéticos , Humanos , Masculino , Melanoma/complicações , Melanoma/patologia , Estudos Retrospectivos , Neoplasias Cutâneas/patologiaRESUMO
Bone lining cells cover > 80% of endosteal surfaces of human cancellous bone. Current research assigns to them a dual role: (1) as a biological membrane regulating exchange of substrates between the bone fluid compartment and the extracellular fluid of bone marrow and (2) as a signaling link between the osteocytic network as mechanical receptor and the osteoclastic cell pool for local induction of bone resorption. Furthermore, a catabolic role has been considered. We therefore examined the presence of matrix-metalloproteinases (MMPs) and their physiological tissue inhibitors (TIMPs) as putative proteolytic elements. Firstly, human cancellous bone from 60 patients was examined by immunofluorescence with antibodies against MMPs and TIMPs. Secondly, we applied laser-assisted microdissection (LMD) to isolate bone lining cells from frozen sections of human trabecular bone. mRNA analysis was performed using a single-cell PCR protocol. Three laser microdissection systems were tested: the new generation of Leica LMD and P.A.L.M. laser pressure catapulting (LPC) were compared to P.A.L.M. laser microdissection and micromanipulation (LMM). In a few pooled cell profiles, mRNA of MMP13, MMP14, TIMP1, and CBFA-1 was clearly detected. By immunofluorescence MMP13 and -14 as well as TIMP1 and -2 were strongly present in lining cells, while MMP2, TIMP3, and TIMP4 showed weak or negative signals. Although the functional impact of these enzymatic components remains open, there is additional evidence for a catabolic function of lining cells. The new diode-laser microdissection with LMD and LPC proved to be especially suitable to gain new insights into the properties of bone lining cells.
Assuntos
Osso e Ossos/enzimologia , Idoso , Reabsorção Óssea , Osso e Ossos/química , Osso e Ossos/citologia , Células Cultivadas , Feminino , Imunofluorescência , Humanos , Masculino , Metaloproteinases da Matriz/análise , Metaloproteinases da Matriz/metabolismo , Microdissecção , Pessoa de Meia-Idade , Inibidor Tecidual de Metaloproteinase-1/análise , Inibidor Tecidual de Metaloproteinase-1/metabolismoRESUMO
The effect of transfection of NIH 3T3 cells by the human ras (c-Ha-ras-1) oncogene on uptake, interconversion, and excretion of polyamines was studied. Uptake and interconversion of spermidine were higher in the ras-transfected cells. Acetylpolyamines were excreted into the medium by the ras-transfected cells, whereas they were retained by NIH 3T3 cells. In addition to acetylpolyamines, some unknown polyamine conjugates occurred in the ras-transfected cells.
Assuntos
Transformação Celular Neoplásica/metabolismo , Genes ras , Poliaminas/metabolismo , Acetilação , Células Cultivadas , TransfecçãoRESUMO
N-Methyl-, N-ethyl-, N-propyl- and N-butylputrescine were assayed as substrates of diamine oxidase from pea seedling and pig kidney. With the exception of N-methylputrescine they were found to be oxidized to the corresponding aminoaldehydes. 1-Methyl-, 2-methyl-, 1-ethyl- and 1-propylputrescine were oxidized by the oxidases at lower rates than the N-alkylderivatives. 1,3-Dimethylputrescine had negligible oxidation rates while 1,4-dimethylputrescine (2,5-diaminohexane) was not a substrate. The oxidation of putrescine by the kidney oxidase was inhibited by 1,4-dimethylputrescine, while the pea oxidase was strongly inhibited by the former as well as by 2-methylputrescine and 1,3-dimethylputrescine. Serum amine oxidase did not oxidize the substituted putrescines although several of the latter inhibited spermidine oxidation by this oxidase.