Pharmacological sequestration of mitochondrial calcium uptake protects against dementia and ß-amyloid neurotoxicity.

All forms of dementia including Alzheimer's disease are currently incurable. Mitochondrial dysfunction and calcium alterations are shown to be involved in the mechanism of neurodegeneration in Alzheimer's disease. Previously we have described the ability of compound Tg-2112x to protect neurons via sequestration of mitochondrial calcium uptake and we suggest that it can also be protective against neurodegeneration and development of dementia. Using primary co-culture neurons and astrocytes we studied the effect of Tg-2112x and its derivative Tg-2113x on ß-amyloid-induced changes in calcium signal, mitochondrial membrane potential, mitochondrial calcium, and cell death. We have found that both compounds had no effect on ß-amyloid or acetylcholine-induced calcium changes in the cytosol although Tg2113x, but not Tg2112x reduced glutamate-induced calcium signal. Both compounds were able to reduce mitochondrial calcium uptake and protected cells against ß-amyloid-induced mitochondrial depolarization and cell death. Behavioral effects of Tg-2113x on learning and memory in fear conditioning were also studied in 3 mouse models of neurodegeneration: aged (16-month-old) C57Bl/6j mice, scopolamine-induced amnesia (3-month-old mice), and 9-month-old 5xFAD mice. It was found that Tg-2113x prevented age-, scopolamine- and cerebral amyloidosis-induced decrease in fear conditioning. In addition, Tg-2113x restored fear extinction of aged mice. Thus, reduction of the mitochondrial calcium uptake protects neurons and astrocytes against ß-amyloid-induced cell death and contributes to protection against dementia of different ethology. These compounds could be used as background for the developing of a novel generation of disease-modifying neuroprotective agents.

The Role of Melanin to Dissociate Oxygen from Water to Treat Retinopathy of Prematurity.

BACKGROUND: Retinopathy of Prematurity (ROP) is a potentially blinding disorder that commonly afflicts premature infants who are born prior to 31weeks of gestation or with a body weight less than 1250 grams (about 2.75 pounds). Another risk factor is excessive oxygen in incubators, which can lead to blindness. A compounding factor is that survival rates for premature infants are rising with concomitantly more cases of ROP. We have reported an unsuspected intrinsic property of melanin to dissociate water. This capability can be considered an alternative treatment option for adult and neonatal diseases. It is known that exogenous surfactant administration suppresses bronchopulmonary dysplasia and consequent death, randomized, controlled trials with various respiratory interventions did not show any significant reductions in morbidity and mortality rates. During a descriptive study about the three leading causes of blindness in the world, the ability of melanin to transform light energy into chemical energy through the dissociation of water molecule was unraveled. Initially, during 2 or 3 years; we tried to link together our findings with the widely accepted metabolic pathways already described in molecular pathway databases, which have been developed to collect and organize the current knowledge on metabolism scattered across a multitude of scientific evidence. OBSERVATIONS: The current report demonstrates the main problems that afflict premature babies with an emphasis on the growth of abnormal vessels in the retina, the explanation for which is unknown until date. We also reported a case of a baby who suffered digestive and respiratory problems with a brain haemorrhage that was successfully treated by laser photocoagulation. We hypothesise that most likely this effect was due to the melanin level and melanin itself produces oxygen via dissociating with water molecules. CONCLUSION: We postulate that the intrinsic effect of melanin may easily convert visible and invisible light into chemical energy via a water dissociation reaction similar to the one in plant's chlorophyll, and markedly elevated with diagnosis and treatment of the complications related to premature babies.

Securinine Derivatives as Potential Anti-amyloid Therapeutic Approach.

BACKGROUND: Oxidative stress and amyloid deposition are tightly interconnected pathological features of Alzheimer disease. In this respect, both amyloid production and aggregation may be stimulated by oxidative stress and also the increase of pathogenic ß-amyloid and its aggregated form lead to oxidative stress progression. Therefore, the search for potential drugs with both antioxidant and antiaggregation properties are of great interest. METHODS: In this study, we described the stereospecific synthesis of alkaloid securinine aminoderivatives. RESULTS: We showed that the newly synthesized compounds possess antioxidant and metal-chelating properties. Indeed, we report that one compound has inhibitory effects towards µ-amyloid aggregation. CONCLUSION: Based on these results, aminoderivatives of securinine scaffold are promising compounds for development of new drugs for the treatment of neurodegenerative diseases.