Biological signals and receptors最新文献

{"title":"Mammalian follicular development and atresia: role of apoptosis.","authors":"E Asselin,&nbsp;C W Xiao,&nbsp;Y F Wang,&nbsp;B K Tsang","doi":"10.1159/000014627","DOIUrl":"https://doi.org/10.1159/000014627","url":null,"abstract":"<p><p>The regulation of follicular development and atresia is a complex process and involves interactions between endocrine factors (gonadotropins) and intraovarian regulators (sex steroids, growth factors and cytokines) in the control of follicular cell fate (i.e. proliferation, differentiation and programmed cell death). Granulosa and theca cells are key players in this fascinating process. As atresia is the fate of most follicles, understanding of how these physiological regulators participate in determining the destiny of the follicle (to degenerate or to ovulate) at cellular and subcellular levels is fundamental. This short review summarizes the role of intraovarian modulators of programmed cell death in the induction of atresia during follicular development.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 2","pages":"87-95"},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014627","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21656437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Apoptosis and chemoresistance in human ovarian cancer: is Xiap a determinant?","authors":"J Li,&nbsp;H Sasaki,&nbsp;Y L Sheng,&nbsp;D Schneiderman,&nbsp;C W Xiao,&nbsp;F Kotsuji,&nbsp;B K Tsang","doi":"10.1159/000014631","DOIUrl":"https://doi.org/10.1159/000014631","url":null,"abstract":"<p><p>Cisplatin-induced apoptosis in epithelial ovarian cancer cells is in part a consequence of suppressed Xiap expression and upregulation of the Fas/FasL system. Changes in the expression of these 'cell death' and 'cell survival' genes lead to activation of caspase-3, and cleavage of MDM2 and FAK. Failure of cancer cells to maintain a balance in the expression of these genes in favor of apoptotic cell death may be an important factor of chemoresistance. Xiap may be a novel target for gene therapy of human ovarian epithelial cancer and, dependent on P53 status, expression of Xiap antisense alone or in combination with wild-type P53 sense may offer a new approach for the treatment of the chemoresistant cancer.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 2","pages":"122-30"},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014631","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21656344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Granulosa cell apoptosis: conservation of cell signaling in an avian ovarian model system.","authors":"A L Johnson","doi":"10.1159/000014628","DOIUrl":"https://doi.org/10.1159/000014628","url":null,"abstract":"<p><p>Ovarian follicle atresia in all vertebrates studied to date is mediated via apoptosis, a process that is often initiated within the granulosa cell layer. While follicle atresia is considered a normal physiological process to insure the greatest chance for ovulation of fertilizable oocytes, abnormally high rates of atresia result in chronic infertility and/or premature termination of fertility (e.g., menopause). Although the vast majority of research to elucidate the molecular ordering of cell signaling during the process of granulosa cell apoptosis has been conducted in mammalian model systems, there is ample evidence to demonstrate that many of the proteins, enzymes and cell-signaling pathways are common to ovarian follicles from avian species. The following review will discuss evidence for the conservation of cellular processes that regulate the fate of granulosa cells from the avian, versus mammalian, ovary during follicle development.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 2","pages":"96-101"},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014628","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21656438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"N-cadherin-mediated cell contact regulates ovarian surface epithelial cell survival.","authors":"J J Peluso","doi":"10.1159/000014630","DOIUrl":"https://doi.org/10.1159/000014630","url":null,"abstract":"<p><p>The present study shows that in cells derived from the rat ovarian surface epithelium (i.e. ROSE-179 cells) the adhesion protein, N-cadherin, binds to the receptor for fibroblast growth factor (FGF). This interaction likely accounts for the ability of the N-cadherin antibody to decrease the activation (i.e. tyrosine phosphorylation) of the FGF receptor and induce apoptosis. The loss of N-cadherin-mediated cell contact also results in the accumulation of beta-catenin within the nucleus. Since beta-catenin also functions as a transcription factor, nuclear beta-catenin may promote mRNA synthesis that is required for ROSE-179 cells to undergo apoptosis in response to serum/calcium withdrawal. This hypothesis requires further testing and validation.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 2","pages":"115-21"},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014630","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21656345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proteolytic and cellular death mechanisms in ovulatory ovarian rupture.","authors":"W J Murdoch","doi":"10.1159/000014629","DOIUrl":"https://doi.org/10.1159/000014629","url":null,"abstract":"<p><p>Collagen breakdown and cellular death (apoptosis and inflammatory necrosis) within the apex of preovulatory ovine follicles are hallmarks of impending ovarian rupture. An integrative mechanism is presented whereby gonadotropic stimulation of urokinase-type plasminogen activator secretion by ovarian surface epithelial cells bordering the preovulatory follicle elicits a localized increase in tissue plasmin, which activates latent collagenases and secretion of tumor necrosis factor-alpha (TNF-alpha) from thecal endothelium. TNF-alpha potentiates collagenolysis (via matrix metalloproteinase gene expression) and (at elevated concentrations) mediates epithelial/vascular dissolution. Incidental damage to DNA of ovarian surface epithelial cells circumjacent to the ruptured follicle is a putative etiological factor in ovarian cancer.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 2","pages":"102-14"},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014629","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21656439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Projection linkage from spinal neurons to both lateral cervical nucleus and solitary tract nucleus in the cat.","authors":"Z Meng,&nbsp;G Lu","doi":"10.1159/000014621","DOIUrl":"https://doi.org/10.1159/000014621","url":null,"abstract":"<p><p>Intracellular recordings from the lumbosacral dorsal horn were made to identify the axonal projection and the afferent innervation of the lateral cervical nucleus (LCN) and solitary tract nucleus (STN) on the spinal neurons of chloralose-anesthetized cats. A total of 49 neurons from laminae III-V in the spinal dorsal horn responded to stimulation of both the LCN and STN. Of these, 28 and 21 neurons responded antidromically and orthodromically to stimulation of the LCN and STN, respectively. Seven of the 28 antidromically activated neurons were followed by one or more responses synaptically driven from the LCN and/or STN. The diameter of these ascending or descending fibers was in the range of A delta fibers. The results indicate that (1) some spinal neurons, namely spinocervical tract-spinosolitary tract (SCT-SST) neurons, issue branched axons of A delta-fibers and dually project to both LCN and STN; (2) some SCT-SST neurons receive innervation from both the LCN and STN; (3) some spinal neurons and interneurons are dually innervated by descending fibers originating from both the LCN and STN, and (4) the convergence and integration between somatic and visceral sensory inputs might occur in the SCT-SST neurons.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 1","pages":"38-44"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014621","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21539380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of protein kinase C activation on G(z)-mediated regulation of type 2 and 6 adenylyl cyclases.","authors":"M K Ho,&nbsp;J S Chan,&nbsp;L Y Yung,&nbsp;Y H Wong","doi":"10.1159/000014619","DOIUrl":"https://doi.org/10.1159/000014619","url":null,"abstract":"<p><p>Three serine-to-alanine mutants of the alpha subunit of the heterotrimeric G protein G(z) (alpha(z)) were examined for their signaling properties in the presence of phorbol ester treatment. All three alpha(z) mutants resembled wild-type alpha(z) in their abilities to inhibit alpha(s)-stimulated type 6 adenylyl cyclase (AC6) and phorbol ester treatment reduced their magnitudes of inhibition. Depending on the permissive condition, the betagamma-mediated stimulation of type 2 adenylyl cyclase (AC2) was differentially regulated by alpha(z) and the three mutants. Mutation of Ser(27) but not Ser(16) of alpha(z) affected the efficient release of betagamma subunits upon receptor activation and abolished the stimulation of phosphorylated but not alpha(s)-stimulated AC2.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 1","pages":"21-8"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014619","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21540105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Purification of rat C6 glioma plasma membranes by affinity partitioning.","authors":"Q Wang,&nbsp;Y Wu,&nbsp;T Aerts,&nbsp;H Slegers,&nbsp;J Clauwaert","doi":"10.1159/000014622","DOIUrl":"https://doi.org/10.1159/000014622","url":null,"abstract":"<p><p>We have studied the feasibility of purifying rat C6 glioma plasma membranes by a phase partitioning approach. The purification procedure involves cell homogenization and fractionation with an aqueous two-phase polymer system followed by selective affinity purification of plasma membranes by a wheat germ agglutinin-coupled polymer system. We demonstrate that the two-phase affinity partitioning technique is a simple and efficient method of isolating cell plasma membranes with high purity and yield. Furthermore, the isolated plasma membranes retain their functional integrity, as shown by the high-affinity insulin-like growth factor-I (IGF-I) binding capacity of IGF-I receptors.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 1","pages":"45-52"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014622","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21539382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pituitary prolactin-secreting tumor formation: recent developments.","authors":"R K Xu,&nbsp;X M Wu,&nbsp;A K Di,&nbsp;J N Xu,&nbsp;C S Pang,&nbsp;S F Pang","doi":"10.1159/000014618","DOIUrl":"https://doi.org/10.1159/000014618","url":null,"abstract":"<p><p>Prolactinoma is the most common type of primary pituitary tumors. It occurs more frequently in women than in men. Dopaminergic agonists are effective in the shrinkage of prolactin-secreting pituitary tumor and are preferred in some patients. However, pituitary radiotherapy may enable the long-term removal of prolactin-secreting tumor cells. Recent evidence suggests that prolactinoma is a heterogeneous disorder with complicated and multifactorial etiology and pathogenesis. Apparently, a thorough understanding of prolactinoma tumorigenesis would be important. To facilitate investigations on tumorigenesis of prolactinoma, animal models for prolactinomas have been developed. These models have expedited our progress in the recent years. Many researchers consider the F(344) rat to be the most sensitive strain of rats to estrogen (E(2))-induced prolactinoma formation. Nonetheless, E(2) treatment for 60 days also induces the formation of pituitary prolactin-secreting adenoma in male Sprague-Dawley (SD) rats. Evidently, the SD rat is also a good animal for prolactinoma investigations. Following E(2) implantation, prolactinomas developed in the eutopic adenohypophysis in situ and/or ectopic pituitary grafted under the renal capsule in SD rats. These observations favor the hypothesis that prolactinoma growth is the result of pathological changes in the adenohypophysis and/or hypothalamus. In the latter case, abnormal release of hypothalamic dopamine, GABA, or brain-gut peptides (such as cholecystokinin, vasoactive intestinal polypeptide, galanin, angiotensin, opioid peptide, gastrin, gastrin-releasing peptide, pancreatic polypeptide, and adrenocorticotropic hormone) results in some of the pathological changes that may lead to hyperprolactinemia and/or prolactinoma development. Dysregulation of prolactin synthesis and secretion may be the result of prolactin gene modulation. In E(2)-induced rat prolactinomas, prolactin mRNA contents and the expression of some proto-oncogenes, e.g. c-myc and c-ras, TGFalpha and TGFbeta1 mRNA were significantly changed. The above findings are consistent with results in human prolactinoma development. In addition, in rats abnormal expression of the prolactin gene was correlated with hypomethylated status of CpG sites in exons 1, 2 and 4 of the prolactin gene, as well as the increase in hypersensitive sites to DNase 1 in the encoding region of the prolactin gene. In E(2)-treated rats, a point mutation with a base substitution from cytidine (C) to adenine (A) was found at the -36-bp site of the proximal promoter of the prolactin gene in eutopic pituitary prolactinomas, but no change was observed in the same sequence of the prolactin gene in ectopic prolactinoma. The association of a base substitution with the hyperexpression of the prolactin gene in eutopic prolactinomas suggests that different mechanisms may mediate the formation of eutopic and ectopic prolactin-secreting tumors. Melatonin decreases the expression of the p","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 1","pages":"1-20"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014618","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21540103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in leucine uptake in the retina of the hamster after traumatic detachment.","authors":"K Yau,&nbsp;W W Li,&nbsp;D T Yew","doi":"10.1159/000014620","DOIUrl":"https://doi.org/10.1159/000014620","url":null,"abstract":"<p><p>Protein metabolism was investigated in detached hamster retinas. By sucking off 0.2 ml of aqueous humor from the anterior chamber through limbic insertion of a 27-gauge needle, a tractional force pulled off the neural retina from the retinal pigment epithelium and created a simple detachment without retinal breaks in the right eyes of the hamsters. The left eyes were left untouched as normal controls and sham controls were induced by simple limbic insertion without suction. The animals were sacrificed at selected intervals of 1, 3, 6, 9, 16, 24, 32 days after the operation. Subsequently, scintillation counting and autoradiography were employed to study retinal protein metabolism using leucine uptake as an index. After tritiated leucine uptake, scintillation counting of radioactive substance indicated that detached retinas had taken in less tritiated leucine than normal controls from day 1 to 6 after the operation, but this change had normalized by day 9. For autoradiography, the change in leucine uptake rate was shown to be different in different layers. All the retinal cells seemed to show a decreased leucine uptake with the exception of the outer nuclear layer, in which leucine appeared to be significantly upregulated. This paper illustrates the patterns of protein metabolism and their change after traumatic detachment as well as their possible recovery.</p>","PeriodicalId":79565,"journal":{"name":"Biological signals and receptors","volume":"9 1","pages":"29-37"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000014620","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21540106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}