Cystiini Pysäkki! Kyseessähän on veressä kiertävä redoxpari cysteiini/cystiini!

Tässä tulee vähän sivukiertoa.
Mistä se cystiini tulee  että m¨Müllerin solu sen sitten nappaa?
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3252963/

Taidanpa oivaltaa:
 Cystiini ja cysteiini on redoxpari ja cystiini kiertäessään veressä on merkki oxidatiivisesta stressistä, jolloin se on ilmeinen retinan solun heräte, joka  stimuloi Müllerin solut kovasti kohottamaan antioksidanttista statustaan ja kaksi  antioksidanttia kerralla tuotetaann,  redoxpari GSH/GSSG ja  hypotauriini/tauriini., joista  hypotauriini on reduktantti ja tauriini oksidantti. 8 Hypotaruiini kohdesolu redusoituu ja tauriini on oksidoitunut)  Reversibeli cysteiini- cystiini- transformaatio on herkkä tuntemaan  oksidaatiotilan, josta  taas  solu saa tietoa, ja  eri solu  järjestää  vasteensa  eri tavalla. Alla on keuhkojen fibroblastista esimerkki. .

LÄHDE: Am J Physiol Lung Cell Mol Physiol. 2007 Oct;293(4):L972-81. Epub 2007 Jul 20.Extracellular cysteine/cystine redox potential controls lung fibroblast proliferation and matrix expression through upregulation of transforming growth factor-beta.
Ramirez A¹, Ramadan B, Ritzenthaler JD, Rivera HN, Jones DP, Roman J.

Abstract

Oxidant stress has been implicated in the pathogenesis of chronic lung disorders like idiopathic pulmonary fibrosis. However, mechanisms that link oxidant stress to fibrogenesis remain partially elucidated. Emerging data suggest an important role for the extracellular thiol/disulfide redox environment. The cysteine (Cys)/cystine (CySS) redox couple represents the predominant low-molecular-weight thiol/disulfide pool found in plasma and is sensitive to aging, smoking, and other host factors.
 We hypothesized that an oxidized extracellular Cys/CySS redox potential (E(h) Cys/CySS) affects lung fibroblasts by inducing intracellular signals that stimulate proliferation and matrix expression. We tested this hypothesis in primary murine lung fibroblasts and found that an oxidized E(h) Cys/CySS (-46 mV) stimulated lung fibroblast proliferation. Furthermore, it stimulated their expression of fibronectin, a matrix glycoprotein highly expressed in fibrotic lung diseases and implicated in lung injury. This stimulatory effect was dependent on protein kinase C activation. Oxidant stress also increased the phosphorylation of cAMP response element binding protein, a transcription factor known for its ability to stimulate fibronectin expression, and increased the expression of mRNAs and proteins coding for the transcription factors nuclear factor (NF)-kappaB and mothers against decapentaplegic homolog 3. Fibroblasts cultured in normal (-80 mV) or reduced (-131 mV) E(h) Cys/CySS showed less induction. Furthermore, fibronectin expression in response to an oxidized E(h) Cys/CySS was associated with expression of transforming growth factor-beta1 (TGF-beta1) and was inhibited by an anti-TGF-beta1 antibody and SB-431542, a TGF-beta1 receptor inhibitor. These studies suggest that extracellular oxidant stress activates redox-sensitive pathways that stimulate lung fibroblast proliferation and matrix expression through upregulation of TGF-beta1.

PMID:

17644756

[PubMed - indexed for MEDLINE]

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