Sp1- and octamer-consensus sequence binding proteins during lens fibre differentiation

Item does not contain fulltex

mRNA made during heat shock enters the first round of translation

Contains fulltext : 34640.pdf (publisher's version ) (Closed access

Basic fibroblast growth factor, insulin and lens differentiation

Item does not contain fulltex

Extralenticular expression of beta-crystallin genes in adult mouse, newborn rat and embryonic Xenopus laevis

Item does not contain fulltex

Extralenticular expression of Xenopus laevis alpha-, beta-, and gamma-crystallin genes

Item does not contain fulltex

A delayed antioxidant response in heat-stressed cells expressing a non-DNA binding HSF1 mutant

To assess the consequences of inactivation of heat shock factor 1 (HSF1) during aging, we analyzed the effect of HSF1 K80Q, a mutant unable to bind DNA, and of dnHSF1, a mutant lacking the activation domain, on the transcriptome of cells 6 and 24 h after heat shock. The primary response to heat shock (6 h recovery), of which 30 % was HSF1-dependent, had decayed 24 h after heat shock in control cells but was extended in HSF1 K80Q and dnHSF1 cells. Comparison with literature data showed that even the HSF1 dependent primary stress response is largely cell specific. HSF1 K80Q, but not HSF1 siRNA-treated, cells showed a delayed stress response: an increase in transcript levels of HSF1 target genes 24 h after heat stress. Knockdown of NRF2, but not of ATF4, c-Fos or FosB, inhibited this delayed stress response. EEF1D_L siRNA inhibited both the delayed and the extended primary stress responses, but had off target effects. In control cells an antioxidant response (ARE binding, HMOX1 mRNA levels) was detected 6 h after heat shock; in HSF1 K80Q cells this response was delayed to 24 h and the ARE complex had a different mobility. Inactivation of HSF1 thus affects the timing and nature of the antioxidant response and NRF2 can activate at least some HSF1 target genes in the absence of HSF1 activity. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12192-012-0400-0) contains supplementary material, which is available to authorized users

Influence of hormones and growth factors on lens protein composition: The effect of dexamethasone and PDGF-AA

Purpose: To investigate the effect of hormones and ocular growth factors on the expression of alpha-, beta-, and gamma-crystallins in rat lens epithelial and fiber cells. Methods: PDGF-AA, EGF, NGF, M-CSF, BMP-2, BMP-4, dexamethasone, and estrogen were tested for their ability to alter the spectrum of crystallins in explanted newborn rat lens epithelial cells or in vitro differentiating newborn rat lens fiber cells. The accumulation of alphaA-, aB-, betaA3/1-, betaB2-, and gamma-crystallin was measured by western blot and dot blot analysis. The morphology of the rat lens explants after culture was examined by hematoxylin-eosin staining, while crystallins were localized by immunofluoresence. Results: Only dexamethasone and PDGF-AA showed an effect on relative crystallin levels. In the presence of dexamethasone the amount of alphaB-crystallin was increased in lens epithelial cells, but dexamethasone did not affect the crystallin spectrum in fiber cells. In rat lens epithelial explants cultured with PDGF-AA an increase in beta- and gamma-crystallin expression was seen. The spectrum of beta- and gamma-crystallins synthesized differed from that present in lens fiber cells. The cells expressing beta- and gamma-crystallin after culture with PDGF-AA were scattered in the epithelial cell layer and retained an epithelial morphology. PDGF-AA did not change the spectrum of crystallins synthesized in lens fiber cells but did enhance the rate of fiber cell differentiation, in agreement with results of others. Conclusions: Both dexamethasone and PDGF-AA influence crystallin gene expression in cultured rat lens epithelial cells. Dexamethasone enhances the expression of alphaB-crystallin while culturing in the presence of PDGF-AA caused an increase in beta- as well as gamma-crystallin synthesis. Since at least the gamma-crystallin genes are known to be silenced in epithelial cells by DNA methylation, PDGF-AA may be able to induce one of the steps towards fiber cell differentiation in some epithelial cells

Synergism between temporally distinct growth factors: bFGF, insulin and lens cell differentiation

Item does not contain fulltex

Fgf Mediated Regulation of Transcription of the Beta-B2-Crystallin Gene in Rat Lens Explants

Item does not contain fulltex

Loss of PRC2 subunits primes lineage choice during exit of pluripotency

Contains fulltext : 241961.pdf (Publisher’s version ) (Open Access