The Pax6 is a multifunctional pairedbox and homeobox containing transcription factor which is involved in several functions of brain, eyes, and pancreas. It regulates expression of genes involved in cell proliferation, differentiation, inflammation, oxidative stress management, and neuropathy. Dynamic changes in the sub-cellular localization of Pax6 are proposed to regulate its activity, however, the underlying mechanism remains poorly understood. The oxidative stress mediated changes were studied in sub-cellular localization of Pax6 in cultured cells derived from the eye (cornea) and pancreas. The impact of induced oxidative stress was investigated on reactive oxygen species scavenger molecules, Superoxide dismutase1 (SOD1) and Catalase, and a critical cell signalling molecule Transforming growth factor-beta (TGF-β1). The cells were treated with three different concentrations of H2O2, viz., 0.3, 1.5, and 3.0 mM. The cell viability was analysed through Trypan blue dye exclusion assay. The localization of Pax6 was observed by immunofluorescence labeling, and alterations in levels of Pax6, SOD1, Catalase, and TGF-β1 were investigated by semi-quantitative RT-PCR. Nucleo-cytoplasmic shuttling of Pax6 was observed in cells of corneal epithelial (SIRC) and pancreatic origins (MIA-PaCa2). The percentage distribution of Pax6 in nuclear and cytoplasmic compartments of SIRC and MIA-PaCa2 cells was analyzed through ImageJ software. Level of hydrogen peroxide affects expression and sub-cellular localization of Pax6. Expression of Pax6 and TGF-β1 are directly associated with changes in sub-cellular localization of Pax6 and modulation in expression of Catalase. This may be the result of a cellular protective mechanism against peroxide-dependent cellular stress.
This is a preview of subscription content, log in to check access.
Authors are highly thankful to Prof. M. K. Thakur, Biochemistry& Molecular Biology Unit, Department of Zoology, Banaras Hindu University, Varanasi, India, for providing the fluorescence microscope facility.
This work was funded by the grants from the Council of Scientific & Industrial Research (CSIR) (37(1521)/12/EMR-II) India. Sachin Shukla acknowledges Senior Research Fellowship from the Council of Scientific & Industrial Research (9/13(442)/2012-EMR-I), New Delhi, India.
Compliance with ethical standards
Conflict of interest
Authors declare that no conflict of interest exist.
Grindley JC, Davidson DR, Hill RE (1995) The role of Pax-6 in eye and nasal development. Development 121:1433–1442PubMedGoogle Scholar
Kioussi C, O’Connell S, St-Onge L, Treier M, Gleiberman AS, Gruss P, Rosenfeld MG (1999) Pax6 is essential for establishing ventral-dorsal cell boundaries in pituitary gland development. Proc Natl Acad Sci USA 96:14378–14382CrossRefPubMedGoogle Scholar
Walther C, Gruss P (1991) Pax-6, a murine paired box gene, is expressed in the developing CNS. Development 113:1435–1449PubMedGoogle Scholar
Thomas MG, Welch C, Stone L, Allan P, Barker RA, White RB (2016) PAX6 expression may be protective against dopaminergic cell loss in Parkinson’s disease. CNS Neurol Disord Drug Targets 15:73–79CrossRefPubMedGoogle Scholar
Chang JY, Hu Y, Siegel E, Stanley L, Zhou YH (2007) PAX6 increases glioma cell susceptibility to detachment and oxidative stress. J Neurooncol 84:9–19CrossRefPubMedGoogle Scholar
Zhang SJ, Li YF, Tan RR, Tsoi B, Huang WS, Huang YH, Tang XL, Hu D, Yao N, Yang X, Kurihara H, Wang Q, He RR (2016) A new gestational diabetes mellitus model: hyperglycemia-induced eye malformation via inhibition of Pax6 in the chick embryo. Dis Model Mech 9:177–186CrossRefPubMedPubMedCentralGoogle Scholar
Yao K, Tan J, Gu WZ, Ye PP, Wang KJ (2007) Reactive oxygen species mediates the apoptosis induced by transforming growth factor beta(2) in human lens epithelial cells. Biochem Biophys Res Commun 354:278–283CrossRefPubMedGoogle Scholar
Ou J, Lowes C, Collinson JM (2010) Cytoskeletal and cell adhesion defects in wounded and Pax6+/- corneal epithelia. Invest Ophthalmol Vis Sci 51:1415–1423CrossRefPubMedGoogle Scholar
Chamberlain CG, Mansfield KJ, Cerra A (2009) Glutathione and catalase suppress TGFbeta-induced cataract-related changes in cultured rat lenses and lens epithelial explants. Mol Vis 15:895–905PubMedPubMedCentralGoogle Scholar
Ou J, Walczysko P, Kucerova R, Rajnicek AM, McCaig CD, Zhao M, Collinson JM (2008) Chronic wound state exacerbated by oxidative stress in Pax6+/- aniridia-related keratopathy. J Pathol 215:421–430CrossRefPubMedGoogle Scholar
Peng Y, Yang PH, Guo Y, Ng SS, Liu J, Fung PC, Tay D, Ge J, He ML, Kung HF, Lin MC (2004) Catalase and peroxiredoxin 5 protect Xenopus embryos against alcohol-induced ocular anomalies. Invest Ophthalmol Vis Sci 45:23–29CrossRefPubMedGoogle Scholar
Jia ZM, Xu W, Yu L, Zhang JJ, Lu L, Lei LS, Wu SG (2005) Effects of cyclosporin A on gene expression profiles of NIT-1 pancreatic beta cell line. Di Yi Jun Yi Da Xue Xue Bao 25:853–857PubMedGoogle Scholar
Dreja T, Jovanovic Z, Rasche A, Kluge R, Herwig R, Tung YC, Joost HG, Yeo GS, Al-Hasani H (2010) Diet-induced gene expression of isolated pancreatic islets from a polygenic mouse model of the metabolic syndrome. Diabetologia 53:309–320CrossRefPubMedGoogle Scholar
Okladnova O, Syagailo YV, Mossner R, Riederer P, Lesch KP (1998) Regulation of PAX-6 gene transcription: alternate promoter usage in human brain. Brain Res Mol Brain Res 60:177–192CrossRefPubMedGoogle Scholar
Yu AL, Fuchshofer R, Birke M, Kampik A, Bloemendal H, Welge-Lussen U (2008) Oxidative stress and TGF-beta2 increase heat shock protein 27 expression in human optic nerve head astrocytes. Invest Ophthalmol Vis Sci 49:5403–5411CrossRefPubMedGoogle Scholar
Hebert-Schuster M, Cottart CH, Laguillier-Morizot C, Raynaud-Simon A, Golmard JL, Cynober L, Beaudeux JL, Fabre EE, Nivet-Antoine V (2011) Catalase rs769214 SNP in elderly malnutrition and during renutrition: is glucagon to blame? Free Radic Biol Med 51:1583–1588CrossRefPubMedGoogle Scholar
Pinson J, Simpson TI, Mason JO, Price DJ (2006) Positive autoregulation of the transcription factor Pax6 in response to increased levels of either of its major isoforms, Pax6 or Pax6(5a), in cultured cells. BMC Dev Biol 6:25CrossRefPubMedPubMedCentralGoogle Scholar
Shukla S, Mishra R (2011) Functional analysis of missense mutations G36A and G51A in PAX6, and PAX6(5a) causing ocular anomalies. Exp Eye Res 93:40–49CrossRefPubMedGoogle Scholar
Valko M, Leibfritz D, Moncol J, Cronin MT, Mazur M, Telser J (2007) Free radicals and antioxidants in normal physiological functions and human disease. Int J Biochem Cell Biol 39:44–84CrossRefPubMedGoogle Scholar
Prochiantz A, Joliot A (2003) Can transcription factors function as cell-cell signalling molecules? Nat Rev Mol Cell Biol 4:814–819CrossRefPubMedGoogle Scholar
Dreos R, Ambrosini G, Groux R, Cavin Périer R, Bucher P (2017) The eukaryotic promoter database in its 30th year: focus on non-vertebrate organisms. Nucleic Acids Res 45(D1):D51–D55CrossRefPubMedGoogle Scholar
Maurya SK, Mishra R (2017) Pax6 binds to promoter sequence elements associated with immunological surveillance and energy homeostasis in brain of aging mice. Ann Neurosci 24(1):20–25CrossRefPubMedPubMedCentralGoogle Scholar