Density Dependent Energy Changes and Adaptive Growth in Populations of Mouse Fibroblasts in Vitro

Author(s):  
R. J. Werrlein
Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
L Moldovan ◽  
O Craciunescu ◽  
L Toma ◽  
A Gaspar ◽  
D Constantin

2009 ◽  
Vol 29 (9) ◽  
pp. 2335-2345 ◽  
Author(s):  
Utsav H. Saxena ◽  
Christina M. H. Powell ◽  
Jill K. Fecko ◽  
Roxanne Cacioppo ◽  
Hubert S. Chou ◽  
...  

ABSTRACT Transcription factor LSF is required for progression from quiescence through the cell cycle, regulating thymidylate synthase (Tyms) expression at the G1/S boundary. Given the constant level of LSF protein from G0 through S, we investigated whether LSF is regulated by phosphorylation in G1. In vitro, LSF is phosphorylated by cyclin E/cyclin-dependent kinase 2 (CDK2), cyclin C/CDK2, and cyclin C/CDK3, predominantly on S309. Phosphorylation of LSF on S309 is maximal 1 to 2 h after mitogenic stimulation of quiescent mouse fibroblasts. This phosphorylation is mediated by cyclin C-dependent kinases, as shown by coimmunoprecipitation of LSF and cyclin C in early G1 and by abrogation of LSF S309 phosphorylation upon suppression of cyclin C with short interfering RNA. Although mouse fibroblasts lack functional CDK3 (the partner of cyclin C in early G1 in human cells), CDK2 compensates for this absence. By transient transfection assays, phosphorylation at S309, mediated by cyclin C overexpression, inhibits LSF transactivation. Moreover, overexpression of cyclin C and CDK3 inhibits induction of endogenous Tyms expression at the G1/S transition. These results identify LSF as only the second known target (in addition to pRb) of cyclin C/CDK activity during progression from quiescence to early G1. Unexpectedly, this phosphorylation prevents induction of LSF target genes until late G1.


2020 ◽  
Vol 17 (3) ◽  
pp. 473-480
Author(s):  
N. M. Kislitsyna ◽  
S. V. Novikov ◽  
N. V. Perova ◽  
S. V. Kolesnik ◽  
A. I. Kolesnik ◽  
...  

Intravitreal use of vital dyes in combination with the action of endoillumination can induce a cyto- and phototoxic effect on posterior eye segment structures. The search for a staining agent with a maximum safety profile to retinal structures, intensively and selectively coloring vitreous body and vitreoretinal interface structure, remains relevant.Objective: to determine comparative viability of NIH / 3T3 mouse fibroblast cell culture with traditional agents for chromovitrectomy and “Vitreocontrast” suspension with and without endovitreal illumination.Materials and methods. NIH / 3T3 mouse fibroblast cultures contacted with agents for chromovitrectomy (MembraneBlue® Dual, Triamcinolone acetonide, “Vitreocontrast” suspension) and the corresponding controls in a volume of 50 μl / well. The test plate was irradiated with a Photon II illuminator (Synergetics, USA), working distance of 5 mm. The control tablet with the introduced preparations was not exposed to light. Next, the cells were washed and incubated, after which the morphology and lysis of the cells, as well as the number of proliferating relatively negative control of fibroblasts, were evaluated using the vital dye PrestoBlue Cell Viability Reagent. Negative control was the complete growth medium for the cultivation of mouse fibroblasts of the NIH / 3T3 line. The results of the cytotoxic reaction of a culture of mouse fibroblasts of the NIH / 3T3 line were interpreted using the table “The degree of cell response”.Results. Studies have shown that exposure to a source of endovitual illumination does not affect the cytotoxic effect of TA suspension and MembraneBlue® Dual dye. The TA suspension, both after light source and without it, has a moderate cytotoxic effect, and MembraneBlue® Dual has no cytotoxic effect on the culture of mouse fibroblasts of the NIH / 3T3 strain. Without light, “Vitreocontrast” suspension does not have cytotoxic effect on mouse fibroblasts culture NIH / 3T3 line. Light irradiation for 1 h increases the cytotoxicity of “Vitreocontrast” suspension to the level of unsharp cytotoxicity allowed by ISO Standard 10993-5-2011.Conclusion. The safety profile of MembraneBlue® Dual and “Vitreocontrast” suspension allows them to be recommended for use in endovitreal surgery. The cyto- and phototoxicity demonstrated in the experiment with TA suspension can reduce the functional outcomes of retinal surgery. 


2019 ◽  
Vol 6 (5) ◽  
pp. 182135 ◽  
Author(s):  
Zakia Kanwal ◽  
Muhammad Akram Raza ◽  
Saira Riaz ◽  
Saher Manzoor ◽  
Asima Tayyeb ◽  
...  

Magnetic cores loaded with metallic nanoparticles can be promising nano-carriers for successful drug delivery at infectious sites. We report fabrication, characteristic analysis and in vitro antibacterial performance of nanocomposites comprising cobalt cores (Co-cores) functionalized with a varied concentration of silver nanoparticles (AgNPs). A two-step polyol process synchronized with the transmetalation reduction method was used. Co-cores were synthesized with cobalt acetate, and decoration of AgNPs was carried out with silver acetate. The density of AgNPs was varied by changing the amount of silver content as 0.01, 0.1 and 0.2 g in the synthesis solution. Both AgNPs and Co-cores were spherical having a size range of 30–80 nm and 200 nm to more than 1 µm, respectively, as determined by scanning electron microscopy. The metallic nature and face-centred cubic crystalline phase of prepared nanocomposites were confirmed by X-ray diffraction. Biocompatibility analysis confirmed high cell viability of MCF7 at low concentrations of tested particles. The antibacterial performance of nanocomposites (Co@AgNPs) against Escherichia coli and Bacillus subtilis was found to be AgNPs density-dependent, and nanocomposites with the highest AgNPs density exhibited the maximum bactericidal efficacy. We therefore propose that Co@AgNPs as effective drug containers for various biomedical applications.


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