ABSTRACT
OBJECTIVES AND DESIGN: In this study, we examine the relationship between C5a and activation of cysteine aspartic acid protease 8 (caspase 8) in human umbilical vein endothelial cells (HUVEC). MATERIALS OR SUBJECTS: Primary cultures of HUVEC were used. TREATMENTS: Recombinant human C5a (50 ng/ml) was used in the presence or absence of 10 microg/ml cycloheximide (CHX). METHODS: HUVEC were treated with C5a alone and in the presence of CHX, then monitored for cell viability, poly- ADP-ribose 1 (PARP-1) and caspase 8 activities. Gene and protein expressions were assessed for caspase 8 and the caspase 8 homologue, FLICE -inhibitory protein (cFLIP). RESULTS: We found a 43.1 +/- 6.9 percent reduction in viability of HUVEC stimulated for 18 h with 50 ng/ml C5a in the presence of 10 microg/ml CHX (p < 0.05). In contrast, the cell viability of cells stimulated for 18 h with 50 ng/ml C5a or 10 microg/ml CHX alone was not significantly different compared to the non-stimulated control. Treatment of HUVEC with C5a induced an increase in caspase 8 activity but did not significantly affect cFLIP levels. CONCLUSIONS: These data suggest caspase 8 activation induced by C5a leads to cell death if protein synthesis of antiapoptotic protein(s) is blocked.
Subject(s)
CASP8 and FADD-Like Apoptosis Regulating Protein/metabolism , Caspase 8/metabolism , Complement C5a/metabolism , Endothelial Cells/metabolism , Cells, Cultured , Cycloheximide/pharmacology , Endothelial Cells/cytology , Endothelial Cells/drug effects , Enzyme Activation , Humans , Poly (ADP-Ribose) Polymerase-1 , Poly(ADP-ribose) Polymerases/metabolismSubject(s)
Gastropoda/anatomy & histology , Penis/anatomy & histology , Penis/physiology , Phylogeny , Testis/anatomy & histology , Testis/physiology , Animals , Copulation/physiology , Male , Penis/cytology , Penis/innervation , Sex Determination Processes , Sex Differentiation , Spermatogenesis/physiology , Testis/cytology , Testis/innervationSubject(s)
Animals , Male , Copulation/physiology , Gastropoda/anatomy & histology , Penis/anatomy & histology , Penis/cytology , Penis/innervation , Penis/physiology , Sex Determination Processes , Phylogeny , Sex Differentiation , Spermatogenesis/physiology , Testis/anatomy & histology , Testis/cytology , Testis/innervation , Testis/physiologySubject(s)
Animals , Male , Copulation/physiology , Gastropoda/anatomy & histology , Penis/anatomy & histology , Penis/cytology , Penis/physiology , Penis/innervation , Sex Determination Processes , Spermatogenesis/physiology , Phylogeny , Sex Differentiation , Testis/anatomy & histology , Testis/cytology , Testis/physiology , Testis/innervationSubject(s)
Animals , Snails , Digestive System , Species Specificity , Microscopy, Electron , Nitrogen/metabolism , Snails , SymbiosisABSTRACT
Intercellular junctions are studied in the epithelium lining the testis of the freshwater snail Pomacea canaliculata by conventional staining and lanthanum tracer techniques. The junctional complex consists of belt desmosomes and septate junctions. Septate junctions are of the pleated-sheet type and they are constantly associated with mitochondria. Gap and tight junctions appear to be absent. These septate junctions seem to be the structural correlate of an epithelial permeability barrier that separate the testis from the extrapallial space where the shell elements are deposited. These junctions may contribute to a functional barrier in the male gonad of Pomacea canaliculata. The results indicate that freshwater prosobranchs have junctional structures very close to those found in other molluscs.