title: Nuclear morphology and c-Jun N-terminal kinase 1 expression differentiate serum-starved oxidative stress signalling from hydrogen peroxide-induced apoptosis in retinal neuronal cell line.
abstract: Oxidative stress induced by serum starvation and H2O2 exposure, both triggers apoptosis in retinal neuronal cell line RGC-5 (retinal ganglion cell-5). We have examined whether, despite excess generation of ROS (reactive oxygen species) and apoptosis induction, there is any dissimilarity in nuclear morphology and apoptotic signalling pathway in RGC-5 under these conditions. Sub-confluent cells were treated either with H2O2 or maintained in SFM (serum-free medium). ROS level was detected along with nuclear morphology and ultrastructural analysis. Generation of excess intracellular ROS, nuclear localization of Bax and caspase 3 activation along with decrease of cellular viability, confirmed apoptosis induction in RGC-5 by 72 h serum starvation and 500 M H2O2 exposure for 1 h. Nuclear swelling as supported by nuclear cytoplasmic ratio and conspicuous black spots with nuclear remodelling were observed only upon SFM, but not with H2O2 treatment. Serum starvation did not alter JNK1 (c-Jun N-terminal kinase 1) expression, although nuclear translocation and higher level of pJNK (phospho-JNK) was evident. Conversely, H2O2 exposure blocked the expression and activation of JNK1 to phospho-JNK as a negligible level of pJNK was present in the cytoplasm. Despite similar ROS generation in both the conditions, difference in nuclear morphology and JNK1 expression leads to the hypothesis that RGC-5 cells may follow different signalling pathways when challenged with serum starvation and H2O2.
authors: Biochemistry Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.
authors: Kaustuv
authors: K
authors: Basu
authors: Arijit
authors: A
authors: Mukhopadhyay
authors: Ilora
authors: I
authors: Ghosh
authors: Kasturi
authors: K
authors: Datta
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure*; D053144:Cell Nucleus Shape; D049109:Cell Proliferation; D002470:Cell Survival; D065150:Cellular Reprogramming; D016895:Culture Media, Serum-Free / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism; D004789:Enzyme Activation; D006861:Hydrogen Peroxide / Q000009:adverse effects; D020935:MAP Kinase Signaling System; D008855:Microscopy, Electron, Scanning; D048055:Mitogen-Activated Protein Kinase 8 / Q000378:metabolism*; D018384:Oxidative Stress; D010766:Phosphorylation; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D055351:Retinal Neurons / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D044967:Serum / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494828:Bax protein, rat; D016895:Culture Media, Serum-Free; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D006861:Hydrogen Peroxide; D048055:Mitogen-Activated Protein Kinase 8; C505410:Casp3 protein, rat; D053148:Caspase 3