Expression of selected apoptosis related genes, MIF, IGIF and TNF alpha, during retinoic acid-induced neural differentiation in murine embryonic stem cells.
Apoptosis plays an important role during embryonic development. Apoptotic cell death is executed by caspases and can be regulated by the Bcl-2 family of genes. Ribonuclease protection assay was used to investigate the expression of selected apoptosis-related genes of the Bcl-2 family, pro-apoptotic Bax, Bad and anti-apoptotic Bcl-2, during differentiation of murine embryonic stem cells (ES) mediated by all-trans-retinoic acid. The mRNA expression of caspase 3, caspase 6 and certain pro-inflammatory cytokines was also investigated simultaneously. ES cells exposed to 1 microM all-trans-retinoic acid on day 8, 9 and 10 of differentiation revealed increased expression of Bax and Bad compared to the vehicle-treated cells. No effect on Bcl-2 mRNA was noted after all-trans-retinoic acid treatment. Increased mRNA expression of caspase 3 and caspase 6 in all-trans-retinoic acid-exposed ES cells suggested that caspases play an important role in retinoic acid-mediated apoptosis during ES differentiation. Increase in the expression of TNF alpha and macrophage migration inhibitory factor (MIF) was noted in retinoic acid-treated cells on day 14. Significant increase observed in interferon gamma inducing factor (IGIF/IL-18) mRNA expression in all-trans-retinoic acid-treated cells on day 14 and 17 did not translate to increased INF gamma expression. No change in the expression of other pro-inflammatory cytokines was noted with all-trans-retinoic acid treatment. The function of TNF alpha, IGIF/IL-18 and MIF in all-trans-retinoic acid-treated cells during ES differentiation and apoptosis is still speculatory. Results suggested that RA-mediated apoptosis during neural differentiation of ES cells involves up-regulation of caspase 3, caspase 6, Bad, and Bax.
Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, 30602, USA.
Suparna A
SA
Sarkar
Raghubir P
RP
Sharma
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D053148:Caspase 3; D053178:Caspase 6; D020169:Caspases / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics*; D016207:Cytokines / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D020382:Interleukin-18 / Q000235:genetics; D008263:Macrophage Migration-Inhibitory Factors / Q000235:genetics; D051379:Mice; D009474:Neurons / Q000166:cytology* / Q000502:physiology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology; D014212:Tretinoin / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D000970:Antineoplastic Agents; D016207:Cytokines; D020382:Interleukin-18; D008263:Macrophage Migration-Inhibitory Factors; D019253:Proto-Oncogene Proteins c-bcl-2; D014409:Tumor Necrosis Factor-alpha; D014212:Tretinoin; C505409:Casp3 protein, mouse; C505516:Casp6 protein, mouse; D053148:Caspase 3; D053178:Caspase 6; D020169:Caspases