Differential expression of voltage-gated Ca2+ conductances in human neuroblastoma NB69 cells cultured in defined serum-free and astrocyte-conditioned media

Glia ◽  
1997 ◽  
Vol 20 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Francisco J. Urbano ◽  
Felipe Sierra ◽  
Jose M. Velasco ◽  
Washington Bu�o
1994 ◽  
Vol 143 (1) ◽  
pp. 157-164 ◽  
Author(s):  
J G Gong ◽  
D McBride ◽  
T A Bramley ◽  
R Webb

Abstract Our previous studies have demonstrated that physiological concentrations of metabolic hormones, including recombinant bovine somatotrophin (BST), insulin-like growth factor-I (IGF-I) and insulin, can significantly stimulate the proliferation of bovine granulosa cells cultured under serum-free conditions. In this study we investigated the effects of these factors on bovine granulosa cell steroidogenesis using the same culture system. Bovine granulosa cells were obtained from antral follicles classified into three size classes: small, <5 mm; medium-sized, 5–10 mm and large, >10 mm in diameter. Whilst not affecting steroidogenesis by granulosa cells from small and medium-sized follicles, BST (10–1000 ng/ml) stimulated the secretion of both oestradiol and progesterone by granulosa cells from large follicles in a dose-dependent manner. Insulin (1–1000 ng/ml) and IGF-I (10–1000 ng/ml) stimulated the secretion of oestradiol and progesterone by granulosa cells from all three size categories of follicles in a dose-dependent manner. FSH (200 ng/ml) alone increased progesterone secretion by granulosa cells from all three size classes of follicles, but had no effect on oestradiol secretion by granulosa cells. Both IGF-I (200 ng/ml) and insulin (30 ng/ml) acted in synergy with FSH (200 ng/ml) to stimulate steroidogenesis by granulosa cells from all three size categories of follicles, but no such interaction was observed between BST (50 ng/ml) and FSH (200 ng/ml). In conclusion, BST, IGF-I and insulin significantly influence the steroidogenic activity of bovine granulosa cells cultured under serum-free conditions. However, unlike their effects on cell proliferation, the minimal effective concentrations of these factors required to stimulate granulosa cell steroidogenesis were higher than those observed in our previous studies in vivo. Journal of Endocrinology (1994) 143, 157–164


1991 ◽  
Vol 99 (2) ◽  
pp. 387-395
Author(s):  
M. Malcovati ◽  
M.L. Tenchini

Attachment, spreading and clustering of second-passage human human keratinocytes in serum-free medium have been evaluated within 24 h after plating, as a function of the density of the inoculum and of time, in two different strains. The results show that attachment is unaffected by cell density and differs significantly from strain to strain. Cell density affects the distribution of attached keratinocytes among three morphologically distinct classes: unspread, spread and clustered cells. The percentage of unspread keratinocytes shows a linear decrease at increasing cell density, and that of spread keratinocytes an increase, resulting from statistically significant increases in the percentages of both single and clustered cells. Spreading on uncoated surfaces appears therefore as an inducible phenomenon. The use of media conditioned by keratinocytes, fibroblasts and HeLa cells shows that keratinocytes specifically secrete a diffusible ‘spreading factor’. We term this phenomenon ‘autocrine induced spreading’. Preliminary physicochemical characterization suggests that a protein could be responsible for the spreading activity of conditioned media. The ‘spreading factor’ seems to act directly on the cells, and not through a modification of the plastic surface of the dishes, since most (greater than 70%) of the spreading activity can be recovered in the conditioned media used in pre-coating experiments. The percentages of clusters follow ‘saturation’ kinetics at increasing cell density, while the percentage of clustered cells increases linearly with the density of inoculum. Time-course experiments show that the rate of spreading is cell density- and strain-independent. The percentages of clusters and of total clustered cells are time-independent, suggesting that cluster formation takes place in suspension.(ABSTRACT TRUNCATED AT 250 WORDS)


1991 ◽  
Vol 27 (5) ◽  
pp. 599-604 ◽  
Author(s):  
Stephen Baghdiguian ◽  
Bernard Verrier ◽  
Monique Roccabianca ◽  
Gilbert Pommier ◽  
Jacques Marvaldi ◽  
...  

2008 ◽  
Vol 294 (1) ◽  
pp. H532-H540 ◽  
Author(s):  
Obaida R. Rana ◽  
Carsten Zobel ◽  
Esra Saygili ◽  
Klara Brixius ◽  
Felix Gramley ◽  
...  

The biomechanical environment to which cells are exposed is important to their normal growth, development, interaction, and function. Accordingly, there has been much interest in studying the role of biomechanical forces in cell biology and pathophysiology. This has led to the introduction and even commercialization of many experimental devices. Many of the early devices were limited by the heterogeneity of deformation of cells cultivated in different locations of the culture plate membranes and were also attached with complicated technical/electronic efforts resulting in a restriction of the reproducibility of these devices. The objective of this study was to design and build a simple device to allow the application of dose-dependent homogeneous equibiaxial static stretch to cells cultured on flexible silicone membranes to investigate biological and biomedical questions. In addition, cultured neonatal rat atrial cardiomyocytes were stretched with the proposed device with different strain gradients. For the first time with this study we could demonstrate that stretch up to 21% caused dose-dependent changes in biological markers such as the calcineurin activity, modulatory calcineurin-interacting protein-1, voltage-gated potassium channel isoform 4.2, and voltage-gated K+ channel-interacting proteins-2 gene expression and transient outward potassium current densities but not the protein-to-DNA ratio and atrial natriuretic peptide mRNA. With both markers mentioned last, dose-dependent stretch alterations could only be achieved with stretch up to 13%. The simple and low-cost device presented here might be applied to a wide range of experimental settings in different fields of research.


2020 ◽  
Vol 54 (5) ◽  
pp. 1068-1082

BACKGROUND/AIMS: Excessive consumption of dietary fat and sugar is associated with an elevated risk of nonalcoholic fatty liver disease (NAFLD). Hepatocytes exposed to saturated fat or sugar exert effects on nearby hepatic stellate cells (HSCs); however, the mechanisms by which this occurs are poorly understood. We sought to determine whether paracrine effects of hepatocytes exposed to palmitate and fructose produced profibrotic transcriptional responses in HSCs. METHODS: We performed expression profiling of mRNA and lncRNA from HSCs treated with conditioned media (CM) from human hepatocytes treated with palmitate (P), fructose (F), or both (PF). RESULTS: In HSCs exposed to CM from palmitate-treated hepatocytes, we identified 374 mRNAs and 607 lncRNAs showing significant differential expression (log2 foldchange ≥ |1|; FDR ≤0.05) compared to control cells. In HSCs exposed to CM from PF-treated hepatocytes, the number of differentially expressed genes was much higher (1198 mRNAs and 3348 lncRNAs); however, CM from fructose-treated hepatocytes elicited no significant changes in gene expression. Pathway analysis of differentially expressed genes showed enrichment for hepatic fibrosis and hepatic stellate cell activation in P- (FDR =1.30E-04) and PF-(FDR =9.24E-06)
groups. We observed 71 lncRNA/nearby mRNA pairs showing differential expression under PF conditions. There were 90 mRNAs and 264 lncRNAs strongly correlated between the PF group and differentially expressed transcripts from a comparison of activated and quiescent HSCs, suggesting that some of the transcriptomic changes occurring in response to PF overlap with HSC activation. CONCLUSION: The results reported here have implications for dietary modifications in the prevention and treatment of NAFLD.


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