RESUMEN
Glucocorticoids (GCs) are frequently used for treating and preventing chronic lung disease and circulatory dysfunction in premature infants. However, there is growing concern about the detrimental effects of systemic GC administration on neurodevelopment. The first choice of GCs to minimize the adverse effects on the developing brain is still under debate. We investigated the effect of commonly used GCs such as dexamethasone (DEX), betamethasone (BET) and hydrocortisone (HDC) on the proliferation of human-induced pluripotent stem cell (iPSC)-derived neuronal progenitor cells (NPCs). In this study, NPCs were treated with various concentrations of GCs and subjected to cell proliferation assays. Furthermore, we quantified the number of microtubule-associated protein 2 (MAP2) positive neurons in NPCs by immunostaining. All GCs promoted NPC proliferation in a dose-dependent manner. We also confirmed that MAP2-positive neurons in NPCs increased upon GC treatment. However, differential effects of GCs on MAP2 positive neurons were observed when we treated NPCs with H2O2. The total numbers of NPCs increased upon any GC treatment even under oxidative conditions but the numbers of MAP2 positive neurons increased only by HDC treatment. GCs promoted human iPSCsâ"derived NPC proliferation and the differential effects of GCs became apparent under oxidative stress. Our results may support HDC as the preferred choice over DEX and BET to prevent adverse effects on the developing human brain.
RESUMEN
UNLABELLED: Menkes disease (MD), an X-linked recessive disorder of copper metabolism caused by mutations in the copper-transporting ATP7A gene, results in growth failure and severe neurodegeneration in early childhood. Subcutaneous copper-histidine injection is the standard treatment for MD, but it has limited clinical efficacy. Furthermore, long-term copper injection causes excess copper accumulation in the kidneys, resulting in renal dysfunction. To attempt to resolve this issue, we used PET imaging with (64)Cu to investigate the effects of disulfiram on copper biodistribution in living mice serving as an animal model for MD (MD model mice). METHODS: Macular mice were used as MD model mice, and C3H/He mice were used as wild-type mice. Mice were pretreated with 2 types of chelators (disulfiram, a lipophilic chelator, and d-penicillamine, a hydrophilic chelator) 30 min before (64)CuCl2 injection. After (64)CuCl2 injection, emission scans covering the whole body were performed for 4 h. After the PET scans, the brain and kidneys were analyzed for radioactivity with γ counting and autoradiography. RESULTS: After copper injection alone, marked accumulation of radioactivity ((64)Cu) in the liver was demonstrated in wild-type mice, whereas in MD model mice, copper was preferentially accumulated in the kidneys (25.56 ± 3.01 percentage injected dose per gram [%ID/g]) and was detected to a lesser extent in the liver (13.83 ± 0.26 %ID/g) and brain (0.96 ± 0.08 %ID/g). Copper injection with disulfiram reduced excess copper accumulation in the kidneys (14.54 ± 2.68 %ID/g) and increased copper transport into the liver (29.42 ± 0.98 %ID/g) and brain (5.12 ± 0.95 %ID/g) of MD model mice. Copper injection with d-penicillamine enhanced urinary copper excretion and reduced copper accumulation in most organs in both mouse groups. Autoradiography demonstrated that disulfiram pretreatment induced copper transport into the brain parenchyma and reduced copper accumulation in the renal medulla. CONCLUSION: PET studies with (64)Cu revealed that disulfiram had significant effects on the copper biodistribution of MD. Disulfiram increased copper transport into the brain and reduced copper uptake in the kidneys of MD model mice. The application of (64)Cu PET for the treatment of MD and other copper-related disorders may be useful in clinical settings.
