Serum repressor element-1 silencing transcription factor levels in alzheimer's patients from a national institute of health in mexico city, elderly and young controls

ABSTRACT Background: Decreased levels of repressor element-1 silencing transcription (REST) factor in the brain, plasma, and neuron-derived exosomes are associated with Alzheimer’s disease (AD). Objective: The objective of the study was to test the viability of serum REST as a possible blood-based biomarker for AD, comparing serum REST levels in AD patients from a National Institute of Health in Mexico City (with different levels of severity and comorbidities), with elderly controls (EC) and young controls (YC). Methods: We used an enzyme-linked immunosorbent assay to determine serum REST levels in AD patients (n = 28), EC (n = 19), and YC (n = 24); the AD patients were classified by dementia severity and comorbidities (depression and microangiopathy) using clinimetric tests and magnetic resonance imaging. Results: Mean serum REST levels did not differ between AD patients, EC, and YC. The severity of AD and the presence of depression or microangiopathy were not associated with serum REST levels. Conclusion: Our results differ from previously published patterns found for plasma and cerebral REST levels. Free serum REST levels may not be a viable AD blood-based biomarker. (REV INVEST CLIN. 2021;73(1):17-22)

Aged garlic extract and S-allylcysteine prevent apoptotic cell death in a chemical hypoxia model

BACKGROUND: Aged garlic extract (AGE) and its main constituent S-allylcysteine (SAC) are natural antioxidants with protective effects against cerebral ischemia or cancer, events that involve hypoxia stress. Cobalt chloride (CoCl2) has been used to mimic hypoxic conditions through the stabilization of the α subunit of hypoxia inducible factor (HIF-1α) and up-regulation of HIF-1α-dependent genes as well as activation of hypoxic conditions such as reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and apoptosis. The present study was designed to assess the effect of AGE and SAC on the CoCl2-chemical hypoxia model in PC12 cells. RESULTS: We found that CoCl2 induced the stabilization of HIF-1α and its nuclear localization. CoCl2 produced ROS and apoptotic cell death that depended on hypoxia extent. The treatment with AGE and SAC decreased ROS and protected against CoCl2-induced apoptotic cell death which depended on the CoCl2 concentration and incubation time. SAC or AGE decreased the number of cells in the early and late stages of apoptosis. Interestingly, this protective effect was associated with attenuation in HIF-1α stabilization, activity not previously reported for AGE and SAC. CONCLUSIONS: Obtained results show that AGE and SAC decreased apoptotic CoCl2-induced cell death. This protection occurs by affecting the activity of HIF-1α and supports the use of these natural compounds as a therapeutic alternative for hypoxic conditions