Microglial depletion exacerbates motor impairment and dopaminergic neuron loss in a 6-OHDA model of Parkinson's disease.

6-hydroxydopamine (6-OHDA) is a common neurotoxin used to induce Parkinson's disease (PD) in mice, exerting neurotoxic effects through the production of reactive oxygen species and microglial activation. However, the role of microglia in PD is still not clear, with contradictory reports showing neuroprotection or exacerbation of neuronal death. Microglial depletion aggravates motor coordination impairments and reduces tyrosine hydroxylase positive neurons in the substantia nigra pars compacta.

Zinc, Vitamin D and Vitamin C: Perspectives for COVID-19 With a Focus on Physical Tissue Barrier Integrity.

Some nutrients play key roles in maintaining the integrity and function of the immune system, presenting synergistic actions in steps determinant for the immune response. Among these elements, zinc and vitamins C and D stand out for having immunomodulatory functions and for playing roles in preserving physical tissue barriers. Considering the COVID-19 pandemic, nutrients that can optimize the immune system to prevent or lower the risk of severe progression and prognosis of this viral infection become relevant.

Antioxidant and anti‑inflammatory mechanisms of action of astaxanthin in cardiovascular diseases (Review).

Cardiovascular diseases are the most common cause of mortality worldwide. Oxidative stress and inflammation are pathophysiological processes involved in the development of cardiovascular diseases; thus, anti‑inflammatory and antioxidant agents that modulate redox balance have become research targets so as to evaluate their molecular mechanisms of action and therapeutic properties. Astaxanthin, a carotenoid of the xanthophyll group, has potent antioxidant properties due to its molecular structure and its arrangement in the plasma membrane, factors that favor the neutralization of reactive oxygen and nitrogen species.

Physical exercise protects against mitochondria alterations in the 6-hidroxydopamine rat model of Parkinson's disease.

Parkinson's disease (PD) is typicaly caractherized by loss of dopaminergic neurons, as well as the presence of mitochondrial impairments. Although physical exercise is known to promote many beneficial effects in healthy subjects, such as enhancing mitocondrial biogenesis and function, it is not clear if these effects are evident after exercise in individuals with PD. The aim of this study was to investigate the effects of two different protocol durations on motor behavior (aphomorphine and gait tests), mitochondrial biogenesis signaling (PGC-1α, NRF-1 and TFAM), structure (oxidative phosphorylation system protein levels) and respiratory chain activity (complex I) in a unilateral PD rat model.

Impairment of PGC-1α-mediated mitochondrial biogenesis precedes mitochondrial dysfunction and Alzheimer's pathology in the 3xTg mouse model of Alzheimer's disease.

Impairment of mitochondrial biogenesis and mitochondrial dysfunction is a prominent feature of Alzheimer's disease (AD). However, the extent to which the impairment of mitochondrial biogenesis influences mitochondrial dysfunction at the onset and during progression of AD is still unclear. Our study demonstrated that the protein expression pattern of the transcription factor pCREB/CREB, together with the protein expression of PGC-1α, NRF1 and TFAM are all significantly reduced in early ages of 3xTg-AD mice.

Lower mitochondrial DNA content but not increased mutagenesis associates with decreased base excision repair activity in brains of AD subjects.

Accumulation of oxidative mitochondrial DNA (mtDNA) damage and impaired base excision repair (BER) in brains have been associated with Alzheimer's disease (AD). However, it is still not clear how these affect mtDNA stability, as reported levels of mtDNA mutations in AD are conflicting. Thus, we investigated whether alterations in BER correlate with mtDNA instability in AD using postmortem brain samples from cognitively normal AD subjects and individuals who show neuropathological features of AD, but remained cognitively normal (high-pathology control).

ExoMeg1: a new exonuclease from metagenomic library.

DNA repair mechanisms are responsible for maintaining the integrity of DNA and are essential to life. However, our knowledge of DNA repair mechanisms is based on model organisms such as Escherichia coli, and little is known about free living and uncultured microorganisms. In this study, a functional screening was applied in a metagenomic library with the goal of discovering new genes involved in the maintenance of genomic integrity.

Effects of post mortem interval and gender in DNA base excision repair activities in rat brains.

Most human tissues used in research are of post mortem origin. This is the case for all brain samples, and due to the difficulty in obtaining a good number of samples, especially in the case of neurodegenerative diseases, male and female samples are often included in the same experimental group. However, the effects of post mortem interval (PMI) and gender differences in the endpoints being analyzed are not always fully understood, as is the case for DNA repair activities.

Fipronil-induced cell death in salivary glands of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) semi-engorged females.

The tick Rhipicephalus sanguineus is currently considered an urban plague. For this reason many studies are intended to find methods to control these ectoparasites. Thus, the present study analyzed the ultrastructural modifications of the salivary glands cells of semi-engorged females of R.

Longitudinal cognitive screening study in community-dwelling individuals.

Unlabelled: Cognitive changes in normal aging can be similar to the alterations that take place in the initial stages of a dementia process. Longitudinal studies can provide a better understanding of this progression.

Objectives: To evaluate the cognitive and functional evolution of community-dwelling individuals without dementia through a three-year longitudinal study.