Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
J Assist Reprod Genet ; 31(1): 45-9, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24221913

ABSTRACT

PURPOSE: To analyze the presence of various histone modifications in ejaculated human spermatozoa METHODS: In this prospective study, seminal ejaculates from 39 normozoospermic individuals were evaluated for semen analysis and the presence of histone modifications in isolated nuclei. RESULTS: We observed heterogeneous presence of histone methylation in normal mature human sperm. We observed that 12 to 30 % of the nuclei of normal sperm contain a heterogeneous distribution of the marks H3K4Me1, H3K9Me2, H3K4Me3, H3K79Me2, and H3K36Me3. Moreover, the presence of these marks is higher in the poor motile fraction of the ejaculate, which is associated with poor morphology and functional quality. In contrast, we did not observe histone acetylation (H3K4Ac and H4K5Ac) in normal or abnormal mature human sperm CONCLUSIONS: Defects in the process of spermatogenesis may alter the correct epigenetic programming in mature sperm. Further studies are required to evaluate the impact of these findings in human infertility.


Subject(s)
Histone-Lysine N-Methyltransferase/metabolism , Histones/metabolism , Spermatogenesis , Spermatozoa/metabolism , Cell Nucleus/metabolism , Epigenesis, Genetic , HeLa Cells , Histone Methyltransferases , Humans , Male , Methylation , Semen Analysis , Spermatogenesis/genetics
2.
Syst Biol Reprod Med ; 59(2): 82-90, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23301776

ABSTRACT

The mammalian sperm nucleus contains an unusually condensed chromatin, due to replacement of the majority of histones by protamines. However, soon after the spermatozoon penetrates the ooplasm at fertilization, decondensation of this densely packed chromatin must occur to allow formation of the male pronucleus and syngamy. Decondensation is accomplished by protamine disulfide bond reduction by oocyte glutathione and replacement of protamines by oocyte histones with the aid of an acceptor molecule. Previous results from our laboratory have demonstrated that heparan sulfate (HS) present in the ooplasm functions as protamine acceptor during human sperm decondensation in vivo. In the present paper, we analyze the role of heparin, structural analogue of HS, and dermatan sulfate (DS) in murine sperm chromatin decondensation in vitro, including the possibility of a synergistic effect between both glycosaminoglycans. Decondensation was assessed under phase contrast microscopy following incubation of murine spermatozoa with glutathione and either heparin, DS, or a combination of both. Ultrastructural changes taking place during decondensation were analyzed by transmission electron microscopy. Both glycosaminoglycans were able to promote the decondensation of murine spermatozoa in vitro but the decondensing ability of heparin was significantly higher. Use of both glycosaminoglycans together revealed the existence of a synergistic effect. Transmission electron microscopy analysis of decondensing spermatozoa supported these findings. Synergism between heparin and DS was observed both in capacitated and non-capacitated spermatozoa but decondensation kinetics was faster in the former. The results obtained indicate a new potential role for dermatan sulfate in murine sperm decondensation at fertilization and provide evidence of differences in the degree of chromatin condensation throughout the murine sperm nucleus.


Subject(s)
Chromatin/metabolism , Dermatan Sulfate/pharmacology , Heparin/pharmacology , Spermatozoa/drug effects , Animals , Dose-Response Relationship, Drug , Male , Mice , Microscopy, Electron , Spermatozoa/metabolism , Spermatozoa/ultrastructure
3.
Biocell ; 31(2): 237-45, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17902272

ABSTRACT

Interaction between parenchyma and stroma is essential for organogenesis, morphogenesis, and differentiation. Mammary gland has being the chosen model for developmental biologist because the most striking changes in morphology and function take place after birth. We have demonstrated a regulation of triglyceride accumulation by protein factors synthesized by normal mouse mammary gland epithelial cells (NMMG), acting on a cell line, 3T3-L1, long used as a model for adipogenesis. In this paper, we demonstrate that this inhibitory effect seems to be shared by other cells of epithelial origin but not by other cell types. We found a regulation of cell proliferation when NMMG cells are cultured in the presence of conditioned media from Swiss 3T3 or 3T3-L1 cells. We found a possible point of regulation for the mammary factor on a key enzyme of the lipid metabolic pathway, the glycerol-3-phosphate dehydrogenase. The inhibitory factor seems to have an effect on this enzyme's activity and reduces it. The results presented herein contribute to the understanding of cell-cell communication in a model of a normal mammary gland.


Subject(s)
Adipocytes, White/metabolism , Cell Communication/physiology , Cell Proliferation , Epithelial Cells/cytology , Mammary Glands, Animal/cytology , Triglycerides/metabolism , 3T3 Cells , 3T3-L1 Cells , Adipocytes, White/cytology , Animals , Cell Differentiation , Cells, Cultured , Culture Media, Conditioned/pharmacology , HeLa Cells , Humans , Mice
4.
Matrix Biol ; 26(6): 419-30, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17513099

ABSTRACT

We have previously shown that during the adipose conversion of these cells the culture medium changed its viscoelastic properties due to the presence of hyaluronan and a chondroitin sulfate proteoglycan [Calvo, J.C., Rodbard, D., Katki, A., Chernick, S., and Yanagishita, M., 1991. Differentiation of 3T3-L1 preadipocytes with 3-isobutyl-1-methylxanthine and dexamethasone stimulates cell-associated and soluble chondroitin 4-sulfate proteoglycans. J. Biol. Chem. 266, 11237-11244., Calvo, J.C., Gandjbakhche, A.H., Nossal, R., Hascall, V.C., and Yanagishita, M., 1993. Rheological effects of the presence of hyaluronic acid in the extracellular media of differentiated 3T3-L1 preadipocyte cultures. Arch. Biochem. Biophys. 302, 468-475]. Here, we analyze the time course for the appearance of these molecules during drug-induced cell differentiation. The synthesis of both hyaluronan and the proteoglycan, was maximal at 48 h in the presence of isobutylmethylxanthine and dexamethasone, but while hyaluronan remained high after changing the culture medium, the proteoglycan dropped to almost basal levels after a few days. Northern analysis revealed the presence of message for a "versican-like" molecule as well as the possibility of alternative splicing. Three major bands of 9.39, 8.48, and 7.69 kb appeared in the analysis. These bands showed a dramatic increase in intensity when RNA from non-differentiated cells was compared to differentiating 3T3-L1 cells. In addition, when the time course of appearance for this message was analyzed, it perfectly correlated the metabolic labeling of the glycosaminoglycans during cell culture. The nucleotide sequencing of two exons revealed between a 100-94% homology with proteoglycan PG-M from murine endothelial cells. At least 13% of the proteoglycan was able to bind hyaluronan. Disruption of the synthesis of the proteoglycan molecule by exogenous addition of xyloside, did not prevent triglyceride accumulation but was inhibitory to preconfluent 3T3-L1 cell proliferation. Coating of plastic culture dishes with conditioned medium from differentiating 3T3-L1 cells, resulted in decreased cell adhesion. Cell adhesion was partially recovered after degradation of hyaluronan and chondroitin sulfate by enzymatic treatment. All these results indicate a possible role of these molecules in the observed changes in the viscoelastic properties of the culture medium, as well as open the field for a more thorough study of their role in 3T3-L1 cell proliferation and/or differentiation.


Subject(s)
Adipocytes/metabolism , Cell Differentiation/physiology , Hyaluronic Acid/metabolism , Versicans/metabolism , 1-Methyl-3-isobutylxanthine/pharmacology , 3T3-L1 Cells , Adipocytes/cytology , Adipocytes/drug effects , Animals , Base Sequence , Binding Sites/genetics , Cell Adhesion/drug effects , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Chondroitin Sulfate Proteoglycans/genetics , Chondroitin Sulfate Proteoglycans/metabolism , Culture Media, Conditioned/metabolism , Culture Media, Conditioned/pharmacology , Dexamethasone/pharmacology , Gene Expression/drug effects , Glycosides/pharmacology , Insulin/pharmacology , Kinetics , Mice , Molecular Sequence Data , Protein Binding , Sequence Homology, Nucleic Acid , Triglycerides/metabolism , Versicans/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...