Differential protein expression in diverse brain areas of Parkinson's and Alzheimer's disease patients.

Many hypotheses have been postulated to define the etiology of sporadic Parkinson's and Alzheimer's disorders (PD and AD) but there is no consensus on what causes these devastating age-related diseases. Braak staging of both pathologies helped researchers to better understand the progression and to identify their prodromal and symptomatic phases. Indeed, it is well accepted that Lewy body pathology and neurofibrillary tangles appearance correlates with disease progression and severity of symptoms in PD and AD, respectively. Additionally, several studies in PD and AD models try to disclose which cellular mechanisms are defaulted and trigger the neurodegenerative process that culminates with neuronal death causing PD and AD classical symptomatology. Herein, we determined expression levels of proteins involved in microtubule assembly, autophagic-lysosomal pathway and unfolded protein response in the cortex, hippocampus and SNpc of PD and AD patients, vascular dementia patients and aged-match controls. The differential expression allowed us to determine which pathways are determinant to synaptic dysfunction and to establish a time line for disease progression. Our results allow us to challenge the hypothesis that both PD and AD pathologies are caused by α-synuclein or Aß pathology propagation throughout the brain in a prion-like manner.

Added sugar and trans fatty acid intake and sedentary behavior were associated with excess total-body and central adiposity in children and adolescents with congenital heart disease.

BACKGROUND: Over the past three decades, the prevalence rate of overweight and obesity has increased in survivors with congenital heart disease, and little is known about the body composition and its association with clinical characteristics and lifestyle factors. OBJECTIVES: To evaluate excess total-body adiposity and central adiposity and, to describe associated factors. METHODS: Cross-sectional study with children and adolescents who underwent procedure to treat congenital heart disease, from January to July 2017. Sociodemographic and clinical characteristics, and lifestyle factors (dietary intake, physical activity, and sedentary behavior) were assessed. Adiposity was assessed using air-displacement plethysmography and waist circumference. Factors associated with excess total-body adiposity and central adiposity were analyzed using logistic regression models. RESULTS: Of 232 patients, 22.4% were identified with excess total-body adiposity and 24.6% with central adiposity. Significant factors positively associated with excess total-body adiposity were intake of added sugar and trans fatty acids, adjusted for confounding factors. Similarly, lifestyle factors were positively associated with central adiposity: intake of added sugar and trans fatty acids, sedentary behavior, and family history of obesity. CONCLUSIONS: Lifestyle factors were associated with excess total-body adiposity and central adiposity. Assessment of body composition and healthy-lifestyle counseling into outpatient care may be the key point to prevent obesity in children and adolescents with congenital heart disease.

Acetylation as a major determinant to microtubule-dependent autophagy: Relevance to Alzheimer's and Parkinson disease pathology.

Protein post-translational modifications (PTMs) that potentiate protein aggregation have been implicated in several neurological disorders, including Alzheimer's (AD) and Parkinson's disease (PD). In fact, Tau and alpha-synuclein (ASYN) undergo several PTMs potentiating their aggregation and neurotoxicity. Recent data posits a role for acetylation in Tau and ASYN aggregation. Herein we aimed to clarify the role of Sirtuin-2 (SIRT2) and HDAC6 tubulin deacetylases as well as p300 acetyltransferase in AD and PD neurodegeneration. We used transmitochondrial cybrids that recapitulate pathogenic alterations observed in sporadic PD and AD patient brains and ASYN and Tau cellular models. We confirmed that Tau protein and ASYN are microtubules (MTs)-associated proteins (MAPs). Moreover, our results suggest that α-tubulin acetylation induced by SIRT2 inhibition is functionally associated with the improvement of MT dynamic determined by decreased Tau phosphorylation and by increased Tau/tubulin and ASYN/tubulin binding. Our data provide a strong evidence for a functional role of tubulin and MAPs acetylation on autophagic vesicular traffic and cargo clearance. Additionally, we showed that an accumulation of ASYN oligomers imbalance mitochondrial dynamics, which further compromise autophagy. We also demonstrated that an increase in Tau acetylation is associated with Tau phosphorylation. We found that p300, HDAC6 and SIRT2 influences Tau phosphorylation and autophagic flux in AD. In addition, we demonstrated that p300 and HDAC6 modulate Tau and Tubulin acetylation. Overall, our data disclose the role of Tau and ASYN modifications through acetylation in AD and PD pathology, respectively. Moreover, this study indicates that MTs can be a promising therapeutic target in the field of neurodegenerative disorders in which intracellular transport is altered.

Mitochondrial Metabolism Power SIRT2-Dependent Deficient Traffic Causing Alzheimer's-Disease Related Pathology.

Multiple lines of evidence state a major role for mitochondrial dysfunction in sporadic Alzheimer's disease (AD) etiopathogenesis. However, the molecular mechanism(s) triggered by mitochondrial deficits that lead to neurodegeneration remain elusive. Herein, we propose a new mechanism by which mitochondrial loss of potential leads to a dysfunction in autophagy/mitophagy due to the overactivation of SIRT2, a tubulin deacetylase that regulates microtubule network acetylation, and provide insights into the association between metabolism, phosphorylation, and Aß aggregation. We observed an increase in SIRT2 levels and a decrease in the acetylation of lys40 of tubulin in AD cells containing patient mtDNA as well as in AD brains. SIRT2 loss of function either with AK1 (a specific SIRT2 inhibitor) or by SIRT2 knockout recovers microtubule stabilization and improves autophagy, favoring cell survival through the elimination of toxic Aß oligomers. Our data provide strong evidence for a functional role of tubulin acetylation on autophagic vesicle traffic and mitochondria degradation. We propose that SIRT2 inhibition may improve microtubule assembly thus representing a valid approach as disease-modifying therapy for AD.

The Upshot of LRRK2 Inhibition to Parkinson's Disease Paradigm.

Mutations in leucine-rich repeat kinase 2 gene (LRRK2) are implicated in autosomal dominant familial and sporadic Parkinson's disease (sPD). Given its relative frequency in PD and its putative function in several cellular pathways that are known to be impaired in the disease, we wanted to tackle LRRK2 physiological role and to address its potential as a PD therapeutic target. We investigated the impact of pharmacological inhibition of LRRK2 kinase activity in control and PD cell function. We provide evidence that physiologically LRRK2, through its kinase activity, regulates mitochondrial fission events and facilitates autophagic degradation by modulating lysosomal cellular localization. Upon LRRK2 inhibition, normal fission decreases, leading to the elongation of mitochondrial network which contributes to a poor degradation of deficient mitochondria. Moreover, LRRK2 inhibition promotes lysosomal perinuclear clustering, through Rab7 that further hinders autophagosomes degradation. These events induce a decrease in the autophagic flow, which contributed directly to a decreased proteolytic degradation of damaged mitochondria. These data resembled the results observed in sPD cells. Interestingly, the LRRK2 kinase activity is increased in sPD cells, and despite its inhibition recovers mitochondrial cellular localization, it did not improve microtubule network-dependent trafficking. Our results provide novel insights into the multiple mechanisms that dictate the association between LRRK2 and mitophagy in sPD, and contribute with new findings that could have important therapeutic implications.

The rescue of microtubule-dependent traffic recovers mitochondrial function in Parkinson's disease.

In Parkinson's disease mitochondrial dysfunction can lead to a deficient ATP supply to microtubule protein motors leading to mitochondrial axonal transport disruption. Compromised axonal transport will then lead to a disorganized distribution of mitochondria and other organelles in the cell, as well as, the accumulation of aggregated proteins like alpha-synuclein. Moreover, axonal transport disruption can trigger synaptic accumulation of autophagosomes packed with damaged mitochondria and protein aggregates promoting synaptic failure. We previously observed that neuronal-like cells with an inherent mitochondrial impairment derived from PD patients contain a disorganized microtubule network, as well as, alpha-synuclein oligomer accumulation. In this work we provide new evidence that an agent that promotes microtubule network assembly, NAP (davunetide), improves microtubule-dependent traffic, restores the autophagic flux and potentiates autophagosome-lysosome fusion leading to autophagic vacuole clearance in Parkinson's disease cells. Moreover, NAP is capable of efficiently reducing alpha-synuclein oligomer content and its sequestration by the mitochondria. Most interestingly, NAP decreases mitochondrial ubiquitination levels, as well as, increases mitochondrial membrane potential indicating a rescue in mitochondrial function. Overall, we demonstrate that by improving microtubule-mediated traffic, we can avoid mitochondrial-induced damage and thus recover cell homeostasis. These results prove that NAP may be a promising therapeutic lead candidate for neurodegenerative diseases that involve axonal transport failure and mitochondrial impairment as hallmarks, like Parkinson's disease and related disorders.

Prodromal metabolic phenotype in MCI cybrids: implications for Alzheimer's disease.

Mild cognitive impairment (MCI) is considered a nosological entity or a translational state between normal aging and sporadic Alzheimer's disease (AD). From brain tissue to peripheral blood samples, it is evident that the early markers of metabolic dysfunction observed in AD have also been found in MCI subjects. These observations obtained from MCI and AD subjects leave open the possibility that mitochondrial dysfunction-induced oxidative damage happening a priori of symptom onset, may trigger other pathological hallmarks, namely Aß oligomerization. In this study, we used a citoplasmic hybrid (cybrid) model created by the repopulation of human teratocarcinoma (NT2) cells depleted of endogenous mitochondrial DNA (mtDNA) with platelets from age-matched controls, MCI and AD subjects. We found mitochondrial deficits in MCI and AD cybrids as compared with controls, such as a decrease in cytochrome c oxidase (COX) activity, a decrease in mitochondrial membrane potential and in mitochondrial cytochrome c content. Consequently, we analyzed parameters of oxidative damage and found that AD and MCI cybrids exhibit an increase in lipid peroxides, higher production of superoxide radicals, and higher content in protein carbonyls. Since our data clearly show alterations in mitochondrial-mediated oxidative damage in MCI cybrids we propose that mitochondrial dysfunction is an early event in idiopathic AD. Moreover, we found that mitochondrial Aß oligomeric content increases in AD, which may exacerbate initial mitochondrial damage. Altogether, our data strongly supports a key role for mitochondria/ mtDNA in aged-driven AD pathology.

Mitochondrial dynamics and neuronal fate in Parkinson's disease.

Along with the impairment of mitochondrial respiration both mitochondrial fission/fusion and mitophagy have been shown to be altered in Parkinson's disease (PD). In both genetic and toxin-induced models of PD an imbalance in mitochondrial morphology is evident, as its correction through modulation of the fission/fusion proteins has been shown to be protective. From the study of the PD-associated genes, namely PINK1 and Parkin, compromised mitochondrial clearance through mitophagy has been associated with the disease etiopathogenesis. Here we propose that an interplay between defective mitochondrial morphology and clearance arises as a crucial player in sentencing neuronal fate in PD.

Mitochondrial metabolic control of microtubule dynamics impairs the autophagic pathway in Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative disorder where the loss of dopaminergic neurons in the substantia nigra and the presence of Lewy bodies in surviving neurons are primary histopathological hallmarks. Recent evidence points to mitochondrial dysfunction as a common upstream event in PD etiopathology. OBJECTIVE: In this overview, we will discuss some of our findings that provide support for the mitochondrial cascade hypothesis, whereas mitochondrial deficits trigger PD pathology through alterations in microtubule integrity and macroautophagy. METHODS: Using, as a PD model, cells that have PD patients' mitochondrial DNA, cells without mitochondrial DNA and MPP(+)-treated cells, we showed that mitochondrial metabolism alteration may underlie changes in the microtubular net and in the autophagic-lysosomal pathway. CONCLUSIONS: Finally, we will endow a potential new therapeutic target for PD pathology.

Mitochondrial Dysfunction: The Road to Alpha-Synuclein Oligomerization in PD.

While the etiology of Parkinson's disease remains largely elusive, there is accumulating evidence suggesting that mitochondrial dysfunction occurs prior to the onset of symptoms in Parkinson's disease. Mitochondria are remarkably primed to play a vital role in neuronal cell survival since they are key regulators of energy metabolism (as ATP producers), of intracellular calcium homeostasis, of NAD(+)/NADH ratio, and of endogenous reactive oxygen species production and programmed cell death. In this paper, we focus on mitochondrial dysfunction-mediated alpha-synuclein aggregation. We highlight some of the findings that provide proof of evidence for a mitochondrial metabolism control in Parkinson's disease, namely, mitochondrial regulation of microtubule-dependent cellular traffic and autophagic lysosomal pathway. The knowledge that microtubule alterations may lead to autophagic deficiency and may compromise the cellular degradation mechanisms that culminate in the progressive accumulation of aberrant protein aggregates shields new insights to the way we address Parkinson's disease. In line with this knowledge, an innovative window for new therapeutic strategies aimed to restore microtubule network may be unlocked.

Mitochondria: the common upstream driver of amyloid-ß and tau pathology in Alzheimer's disease.

Mitochondrial dysfunction has been widely implicated in the etiology of Alzheimer's disease (AD). Evidence shows a mitochondrial-mediated impairment of autophagy that potentiates amyloid-ß (Aß) deposition. Accordingly, recent data obtained from AD models, in which mitochondrial alterations are a prominent feature, demonstrated abnormalities in microtubule network, involving tubulin and tau post-translational modifications. In this review we will discuss mitochondrial-regulated processes where mitochondrial malfunction is likely to start a sequence of events leading to sirtuin-2 activation, microtubule network breakdown, and impairment of the autophagic pathway. Because sirtuin-2 activity depends on cellular NAD+ availability, mitochondrial regulation of NAD+ levels may contribute to an increase in sirtuin-mediated tubulin deacetylation. A vicious cycle become installed which potentiates tau hyperphosphorylation, together with Aß overproduction and deposition. Overall, targeting microtubule network constitutes a promising strategy for pharmacological therapy in AD.

Mitochondrial metabolism modulation: a new therapeutic approach for Parkinson's disease.

Mitochondrial metabolism is a highly orchestrated phenomenon in which many enzyme systems cooperate in a variety of pathways to dictate cellular fate. As well as its vital role in cellular energy metabolism (ATP production), mitochondria are powerful organelles that regulate reactive oxygen species production, NAD+/NADH ratio and programmed cell death. In addition, mitochondrial abnormalities have been well recognized to contribute to degenerative diseases, like Parkinson's disease (PD). Particularly a deficiency in the mitochondrial respiratory chain complex I and cristae disruption have been consistently described in PD. Moreover, the products of PD-familial genes, including alpha-synuclein, Parkin, PINK1, DJ-1, LRRK2 and HTR2A, were shown to localize to the mitochondria under certain conditions. It seems that PD has a mitochondrial component so events that would modulate normal mitochondrial functions may compromise neuronal survival. However, it remains an open question whether alterations of these pathways lead to different aspects of PD or whether they converge at a point that is the common denominator of PD pathogenesis. In this review we will focus on mitochondrial metabolic control and its implications on sirtuins activation, microtubule dynamics and autophagic-lysosomal pathway. We will address mitochondrial metabolism modulation as a new promising therapeutic tool for PD.

Mitochondrial control of autophagic lysosomal pathway in Alzheimer's disease.

When first described by Alois Alzheimer in 1907, AD was seen as a disorder that causes dementia and characterized by two defining neuropathological lesions, later associated with all forms of AD. While the etiology of AD remains largely unclear, there is accumulating evidence suggesting that mitochondrial dysfunction occurs prior to the onset of symptoms in AD. Mitochondria are exceptionally poised to play a crucial role in neuronal cell survival or death because they are regulators of both energy metabolism and apoptotic pathways. This review is mainly focused in the discussion of evidence suggesting a clear association between mitochondrial dysfunction, autophagy impairment and amyloid-beta accumulation in Alzheimer's disease pathophysiology. The knowledge that autophagic insufficiency may compromise the cellular degradation mechanisms that may culminate in the progressive accumulation of dysfunctional mitochondria, aberrant protein aggregates buildup and lysossomal burden shield new insights to the way we address Alzheimer's disease. In line with this knowledge an innovative window for new therapeutic strategies aimed to activate or ameliorate macroautophagy may be opened.

Importância da reabilitação protética da região óculo-palpebral: relato de caso / Importance of rehabilitation of the prosthetic region óculo-palpebral: case report

As perdas buco-maxilo faciais causam grande constrangimento e sofrimento aos seus portadores, especialmente aquelas passíveis de reabilitação somente através da prótese. Este trabalho relata o caso de um paciente, sexo feminino, leucoderma e com 66 anos de idade, atendido na Clínica de Prótese Buco-Maxilo Facial da Faculdade de Odontologia de Pernambuco da Universidade de Pernambuco (FOP/UPE), portador de uma mutilação na região óculo-palpebral que teve como fator etiológico um câncer da região orbitária, descrevendo-se a técnica e a importância da reabilitação protética facial nos aspectos estéticos e psicossociais.

The maxillofacial losses cause great constraint and sadness especially those with need of rehabilitation only through prosthesis. This work present a case of a patient, feminine, leucoderm and 66 years of age, seeking for treatment at Clinic of Maxillofacial Prosthetic of the Dental School of the University of Pernambuco (FOP/UPE). The patient had a mutilation in the oculo-palpebral region and the etiologic factor was a cancer on the orbital region. This case report aimed also to describe its technique and the importance of the facial prosthetic rehabilitation to aesthetic and psicossociais aspects.

Estimated intake of the sweeteners, acesulfame-K and aspartame, from soft drinks, soft drinks based on mineral waters and nectars for a group of Portuguese teenage students.

In a survey of levels of acesulfame-K and aspartame in soft drinks and in light nectars, the intake of these intense sweeteners was estimated for a group of teenage students. Acesulfame-K was detected in 72% of the soft drinks, with a mean concentration of 72 mg l(-1) and aspartame was found in 92% of the samples with a mean concentration of 89 mg l(-1). When data on the content of these sweeteners in soft drinks were analysed according to flavour, cola drinks had the highest mean levels for both sweeteners with 98 and 103 mg l(-1) for acesulfame-K and aspartame, respectively. For soft drinks based on mineral water, aspartame was found in 62% of the samples, with a mean concentration of 82 mg l(-1) and acesulfame-K was found in 77%, with a mean level of 48 mg l(-1). All samples of nectars contained acesulfame-K, with a mean concentration of 128 mg l(-1) and aspartame was detected in 80% of the samples with a mean concentration of 73 mg l(-1). A frequency questionnaire, designed to identify adolescents having high consumption of these drinks, was completed by a randomly selected sample of teenagers (n = 65) living in the city of Coimbra, in 2007. The estimated daily intakes (EDI) of acesulfame-K and aspartame for the average consumer were below the acceptable daily intakes (ADIs). For acesulfame-K, the EDI was 0.7 mg kg(-1) bw day(-1) for soft drinks, 0.2 mg kg(-1) bw day(-1) for soft drinks based on mineral waters, and 0.5 mg kg(-1) bw day(-1) for nectars, representing 8.0%, 2.2%, and 5.8% of the ADI, respectively. A similar situation was observed for aspartame. In this way, the EDI for soft drinks was 1.1 mg kg(-1) day(-1), representing only 2.9% of the ADI. In respect of nectars, the EDI was 0.2 mg kg(-1) bw day(-1), representing 0.5% of the ADI. Soft drinks based on mineral waters showed the lowest EDI values of 0.3 mg kg(-1) bw day(-1), accounting for 0.7% of the ADI.

The key role of mitochondria in Alzheimer's disease.

Mitochondria are uniquely poised to play a pivotal role in neuronal cell survival or death because they are regulators of both energy metabolism and apoptotic pathways. This review is mainly focused in the discussion of evidence suggesting a clear association between amyloid-beta toxicity, mitochondrial dysfunction, oxidative stress and neuronal damage/death in Alzheimer's disease pathophysiology. The knowledge that mitochondrial dysfunction has a preponderant role in Alzheimer's disease opened a window for new therapeutic strategies aimed to preserve/ameliorate mitochondrial function. Based on recent developments in mitochondrial research, increased pharmacological and pharmaceutical efforts have lead to the emergence of 'Mitochondrial Medicine' as a whole new field of biomedical research being this topic discussed in the last section of this review.

Protective effect of zinc on amyloid-beta 25-35 and 1-40 mediated toxicity.

Amyloid beta-peptide (Abeta) is widely held to be associated with Alzheimer's disease, the insoluble aggregates of the peptide being the major constituents of senile plaques. In this study, we evaluated the effect of Zn(2+) (5, 50 and 200 microM) on Abeta induced toxicity using the human teratocarcinome (NT2) cell line. Our results proved that 50 and 200 microM Zn(2+) protected NT2 cells from Abeta 25-35 toxicity. Zinc was also shown to be effective by preventing the loss of mitochondrial membrane potential (DeltaPsi(m)) induced by Abeta 25-35, not allowing cytochrome c release from mitochondria, and subsequently, caspase 3 activation. However, when the cells were treated with Abeta 1-40, only Zn(2+) 5 microM had a protective effect. We have further observed that 5 microM Zn(2+) prevented Abeta 1-40 aggregation into a beta-sheet structure. Considering the results presented, we argue that Zn(2+) has a concentration-dependent protective effect.

Alzheimer's disease-associated neurotoxic mechanisms and neuroprotective strategies.

The characteristic hallmarks of Alzheimer's disease (AD), the most common form of dementia in the elderly, include senile plaques, mainly composed of beta-amyloid (Abeta) peptide, neurofibrillary tangles and selective synaptic and neuronal loss in brain regions involved in learning and memory. Genetic studies, together with the demonstration of Abeta neurotoxicity, led to the development of the amyloid cascade hypothesis to explain the AD-associated neurodegenerative process. However, a modified version of this hypothesis has emerged, the Abeta cascade hypothesis, which takes into account the fact that soluble oligomeric forms and protofibrils of Abeta and its intraneuronal accumulation also play a key role in the pathogenesis of the disease. Recent evidence posit that synaptic dysfunction triggered by non fibrillar Abeta species is an early event involved in memory decline in AD. The current understanding of the molecular mechanisms responsible for impaired synaptic function and cognitive deficits is outlined in this review, focusing on oxidative stress and disturbed metal ion homeostasis, Ca(2+) dysregulation, mitochondria and endoplasmic reticulum dysfunction, cholesterol dyshomeostasis and impaired neurotransmission. The activation of apoptotic cell death as a mechanism of neuronal loss in AD, and the prominent role of neuroinflammation in this neurodegenerative disorder, are also reviewed herein. Furthermore, we will focus on the more relevant therapeutical strategies currently used, namely those involving antioxidants, drugs for neurotransmission improvement, hormonal replacement, gamma- and beta- secretase inhibitors, Abeta clearance agents (Abeta immunization, disruption of Abeta fibrils, modulation of the cholesterol-mediated Abeta transport), non-steroidal anti-inflammatory drugs (NSAIDs), microtubules stabilizing drugs and kinase inhibitors.

Neurodegenerative pathways in Parkinson's disease: therapeutic strategies.

Parkinson's disease (PD), considered one of the major neurological disorders, is characterized by the loss of dopaminergic neurons in the pars compacta of the substantia nigra and by the presence of intraneuronal cytoplasmic inclusions called Lewy bodies. The causes for degeneration of PD neurons remain unclear, however, recent findings contributed to clarify this issue. This review will discuss the current understanding of the mechanisms underlying Parkinson's disease pathogenesis, focusing on the current and potential therapeutic strategies for human treatment.

Organochlorine pesticide residues in European sardine, horse mackerel and Atlantic mackerel from Portugal.

This paper reports the results for the surveillance of nine organochlorine pesticides (HCH isomers (alpha, beta, e, gamma), p,p'-DDD, p,p'-DDT, p,p'-DDE, p,p'-DDD, HCB and aldrin) in muscle of three fish species, European pilchard (Sardina pilchardus), Atlantic horse mackerel (Trachurus trachurus) and Atlantic mackerel (Scomber scombrus). Analytical methodology included n-hexane extraction, clean-up with 2% deactivated Florisil, and quantification with gas chromatography-electron capture detection (GC-ECD). The highest mean concentrations were found for p,p'-DDT in sardine and mackerel at levels of 30.1 and 109.9 microg kg(-1), respectively, and for p,p'-DDD in horse mackerel at 51.9 microg kg(-1). Three species had higher levels for S-DDT than S-HCH. The estimated daily intake of organochlorine pesticides in the three species showed that in sardine, the highest EDIs were found for aldrin, at 1.8 ng kg(-1) bw day(-1), which represents 1.8% of the acceptable daily intake (ADI), and for ss-HCH, at 4.0 ng kg(-1) bw day(-1), representing 0.4% of ADI. Lowest values were found for Atlantic mackerel. Statistical analysis to determine the differences in mean concentrations of pesticides between species, and any correlation between groups of residues related with each one of the species, was undertaken.