Phosphatidylinositol Transfer Protein Expression Altered by Aging and Parkinson Disease

BDNF/TrkB activators in Parkinson's disease: A new therapeutic strategy

Parkinson's disease (PD) is a neurodegenerative disorder of the brain and is manifested by motor and non-motor symptoms because of degenerative changes in dopaminergic neurons of the substantia nigra. PD neuropathology is associated with mitochondrial dysfunction, oxidative damage and apoptosis. Thus, the modulation of mitochondrial dysfunction, oxidative damage and apoptosis by growth factors could be a novel boulevard in the management of PD. Brain-derived neurotrophic factor (BDNF) and its receptor tropomyosin receptor kinase type B (TrkB) are chiefly involved in PD neuropathology. BDNF promotes the survival of dopaminergic neurons in the substantia nigra and enhances the functional activity of striatal neurons. Deficiency of the TrkB receptor triggers degeneration of dopaminergic neurons and accumulation of α-Syn in the substantia nigra. As well, BDNF/TrkB signalling is reduced in the early phase of PD neuropathology. Targeting of BDNF/TrkB signalling by specific activators may attenuate PD neuropathology. Thus, this review aimed to discuss the potential role of BDNF/TrkB activators against PD. In conclusion, BDNF/TrkB signalling is decreased in PD and linked with disease severity and long-term complications. Activation of BDNF/TrkB by specific activators may attenuate PD neuropathology.

Lipid Mediated Brain Disorders: A Perspective

The brain, one of the most resilient organs of the body is highly enriched in lipid content, suggesting the essential role of lipids in brain physiological activities. Lipids constitute an important structural part of the brain and act as a rich source of metabolic energy. Besides, lipids in their bioactive form (known as bioactive lipids) play an essential signaling and regulatory role, facilitating neurogenesis, synaptogenesis, and cell-cell communication. Brain lipid metabolism is thus a tightly regulated process. Any alteration/dysregulation of lipid metabolism greatly impact brain health and activity. Moreover, since central nervous system (CNS) is the most metabolically active system and lacks an efficient antioxidative defence system, it acts as a hub for the production of reactive oxygen species (ROS) and subsequent lipid peroxidation. These peroxidation events are reported during pathological changes such as neuronal tissue injury and inflammation. Present review is a modest attempt to gain insights into the role of dysregulated bioactive lipid levels and lipid oxidation status in the pathogenesis and progression of neurodegenerative disorders. This may open up new avenues exploiting lipids as the therapeutic targets for improving brain health, and treatment of nervous system disorders.

Identification of the Raman Salivary Fingerprint of Parkinson's Disease Through the Spectroscopic- Computational Combinatory Approach

Despite the wide range of proposed biomarkers for Parkinson's disease (PD), there are no specific molecules or signals able to early and uniquely identify the pathology onset, progression and stratification. Saliva is a complex biofluid, containing a wide range of biological molecules shared with blood and cerebrospinal fluid. By means of an optimized Raman spectroscopy procedure, the salivary Raman signature of PD can be characterized and used to create a classification model. Raman analysis was applied to collect the global signal from the saliva of 23 PD patients and related pathological and healthy controls. The acquired spectra were computed using machine and deep learning approaches. The Raman database was used to create a classification model able to discriminate each spectrum to the correct belonging group, with accuracy, specificity, and sensitivity of more than 97% for the single spectra attribution. Similarly, each patient was correctly assigned with discriminatory power of more than 90%. Moreover, the extracted data were significantly correlated with clinical data used nowadays for the PD diagnosis and monitoring. The preliminary data reported highlight the potentialities of the proposed methodology that, once validated in larger cohorts and with multi-centered studies, could represent an innovative minimally invasive and accurate procedure to determine the PD onset, progression and to monitor therapies and rehabilitation efficacy.

Lipid and Lipid Raft Alteration in Aging and Neurodegenerative Diseases: A Window for the Development of New Biomarkers

Lipids in the brain are major components playing structural functions as well as physiological roles in nerve cells, such as neural communication, neurogenesis, synaptic transmission, signal transduction, membrane compartmentalization, and regulation of gene expression. Determination of brain lipid composition may provide not only essential information about normal brain functioning, but also about changes with aging and diseases. Indeed, deregulations of specific lipid classes and lipid homeostasis have been demonstrated in neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). Furthermore, recent studies have shown that membrane microdomains, named lipid rafts, may change their composition in correlation with neuronal impairment. Lipid rafts are key factors for signaling processes for cellular responses. Lipid alteration in these signaling platforms may correlate with abnormal protein distribution and aggregation, toxic cell signaling, and other neuropathological events related with these diseases. This review highlights the manner lipid changes in lipid rafts may participate in the modulation of neuropathological events related to AD and PD. Understanding and characterizing these changes may contribute to the development of novel and specific diagnostic and prognostic biomarkers in routinely clinical practice.

The Role of Lipids in Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative disease characterized by a progressive loss of dopaminergic neurons from the nigrostriatal pathway, formation of Lewy bodies, and microgliosis. During the past decades multiple cellular pathways have been associated with PD pathology (i.e., oxidative stress, endosomal-lysosomal dysfunction, endoplasmic reticulum stress, and immune response), yet disease-modifying treatments are not available. We have recently used genetic data from familial and sporadic cases in an unbiased approach to build a molecular landscape for PD, revealing lipids as central players in this disease. Here we extensively review the current knowledge concerning the involvement of various subclasses of fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, and lipoproteins in PD pathogenesis. Our review corroborates a central role for most lipid classes, but the available information is fragmented, not always reproducible, and sometimes differs by sex, age or PD etiology of the patients. This hinders drawing firm conclusions about causal or associative effects of dietary lipids or defects in specific steps of lipid metabolism in PD. Future technological advances in lipidomics and additional systematic studies on lipid species from PD patient material may improve this situation and lead to a better appreciation of the significance of lipids for this devastating disease.

Proteomic Analysis of Mouse Brain Subjected to Spaceflight

There is evidence that spaceflight poses acute and late risks to the central nervous system. To explore possible mechanisms, the proteomic changes following spaceflight in mouse brain were characterized. Space Shuttle Atlantis (STS-135) was launched from the Kennedy Space Center (KSC) on a 13-day mission. Within 3–5 h after landing, brain tissue was collected to evaluate protein expression profiles using quantitative proteomic analysis. Our results showed that there were 26 proteins that were significantly altered after spaceflight in the gray and/or white matter. While there was no overlap between the white and gray matter in terms of individual proteins, there was overlap in terms of function, synaptic plasticity, vesical activity, protein/organelle transport, and metabolism. Our data demonstrate that exposure to the spaceflight environment induces significant changes in protein expression related to neuronal structure and metabolic function. This might lead to a significant impact on brain structural and functional integrity that could affect the outcome of space missions.

Proanthocyanidins exert a neuroprotective effect via ROS/JNK signaling in MPTP‑induced Parkinson's disease models in vitro and in vivo

The pathological alterations of Parkinson's disease (PD) predominantly manifest as a loss of dopaminergic neurons in the substantia nigra, which may be caused by oxidative stress damage. Proanthocyanidins (PCs) are a class of compounds found in various plants, which have significant antioxidant and free radical-scavenging activity. The present study investigated the protective effects and underlying mechanisms of PCs in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model in vitro and in vivo. MTT assays were used to detect cell viability, and flow cytometry and TUNEL assays were used to detect cell apoptosis. Mitochondrial membrane potential (MMP) alterations were investigated using a JC-1 MMP Assay kit. The pole test was used to measure motor behavior in a mouse model of PD. Levels of reactive oxygen species (ROS) were measured using the fluorescent probe, 2′,7′-dichlorodihydrofluorescein diacetate. Immunohistochemistry and western blotting were performed to detect the expression levels of proteins associated with PD. In vitro, it was demonstrated that in MPTP-treated PC12 cells, PCs increased cell viability and reduced cell apoptosis in a dose-dependent manner. In vivo, it was revealed that PC treatment inhibited striatal dopamine depletion, which resulted in significant improvements in PD-like movement impairment. Reactive oxygen species (ROS) production and MPTP-induced apoptosis were also inhibited. Furthermore, the results demonstrated that the neuroprotective activity of PCs may be mediated via the inhibition of ROS generation, as well as modulation of c-Jun N-terminal kinase activation. Taken together, these data revealed that PCs may exert neuroprotective effects in in vivo and in vitro PD models, and may have potential in the prevention or treatment of PD.

Neuroprotection by tetrahydroxystilbene glucoside in the MPTP mouse model of Parkinson's disease

Our in vitro experiments suggested that tetrahydroxystilbene glucoside (TSG) affords a significant neuroprotective effect against MPP⁺-induced damage and apoptosis in PC12 cells though activation of the PI3K/Akt pathway. This study was aimed to investigate the potential neuroprotective effect of TSG in 1-methyl-4-phenyl-1,2,3,6-tetrahydropypridine (MPTP)-treated mouse model of Parkinson's disease (PD). We found that treatment of TSG protected dopaminergic neurons by preventing MPTP-induced decreases in substantia nigra tyrosine hydroxylase (TH)-positive cells and striatal dopaminergic transporter (DAT) protein levels. Furthermore, it was also associated with increasing striatal Akt and GSK3β phosphorylation, up-regulation of the Bcl-2/BAD ratio, and inhibition of the activation of caspase-9 and caspase-3. These results showed that TSG promoted dopamine neuron survival in vivo, the PI3K/Akt signaling pathway may have mediated the protection of TSG against MPTP, suggesting that TSG treatment might represent a neuroprotective treatment for PD.

Protective effects of resveratrol and quercetin against MPP+ -induced oxidative stress act by modulating markers of apoptotic death in dopaminergic neurons

Reactive oxygen species produced by oxidative stress may participate in the apoptotic death of dopamine neurons distinctive of Parkinson's disease. Resveratrol, a red wine extract, and quercetin, found mainly in green tea, are two natural polyphenols, presenting antioxidant properties in a variety of cellular paradigms. The aim of this study was to evaluate the effect of resveratrol and quercetin on the apoptotic cascade induced by the administration of 1-methyl-4-phenylpyridinium ion (MPP(+)), a Parkinsonian toxin, provoking the selective degeneration of dopaminergic neurons. Our results show that a pre-treatment for 3 h with resveratrol or quercetin before MPP(+) administration could greatly reduce apoptotic neuronal PC12 death induced by MPP(+). We also demonstrated that resveratrol or quercetin modulates mRNA levels and protein expression of Bax, a pro-apoptotic gene, and Bcl-2, an anti-apoptotic gene. We then evaluated the release of cytochrome c and the nuclear translocation of the apoptosis-inducing factor (AIF). Altogether, our results indicate that resveratrol and quercetin diminish apoptotic neuronal cell death by acting on the expression of pro- and anti-apoptotic genes. These findings support the role of these natural polyphenols in preventive and/or complementary therapies for several human neurodegenerative diseases caused by oxidative stress and apoptosis.

D-beta-hydroxybutyrate prevents MPP+-induced neurotoxicity in PC12 cells

Numerous studies show that D-beta-Hydroxybutyrate (DbetaHB) is neuroprotective. The present study was to explore the neuroprotective effects of DbetaHB against the cell death and apoptosis induced by 1-methyl-4-phenylpyridinium ion (MPP+) in PC12 cells. PC12 cells were pretreated with DbetaHB and followed by MPP+ exposure. The cell viability was determined by MTT assay. The morphological characteristics of apoptosis was observed by Acridine Orange (AO) staining and apoptotic rates were measured by flow cytometer. The product of lipid peroxidation, malondialdehyde (MDA), was measured using thiobarbituric acid method. The mitochondrial membrane potential (MMP), intracellular ROS and total glutathione were detected by microplate reader. In PC12 cells, pretreatment with DbetaHB significantly reduced MPP+-induced the decrease of cell viability. AO staining and flow cytometric analysis found DbetaHB inhibited MPP+-induced apoptosis. The measurement of MDA formation showed that DbetaHB alleviated lipid peroxidation induced by MPP+. The loss of MMP induced by MPP+ was preventive by DbetaHB. The changes of intracellular ROS and total glutathione induced by MPP+ were reversed by DbetaHB. DbetaHB protected PC12 cells against MPP+-induced death and apoptosis.

Resveratrol, a red wine polyphenol, protects dopaminergic neurons in MPTP-treated mice

Phytoestrogens, and particularly resveratrol, a red wine polyphenol, are currently under study for their therapeutic antioxidant properties. Administration of the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to C57BL/6 mice targets nigrostriatal dopaminergic neurons, leading to cell death and striatal dopamine (DA) depletion. The aim of the present study was to analyze the protective effect of a diet rich in resveratrol against MPTP-induced neuronal death. Male mice were kept on a phytoestrogen-free diet, supplemented or not with 50 or 100 mg/kg/day of resveratrol for 1 or 2 weeks, after which MPTP was injected intraperitoneally. We observed that daily administration of resveratrol prevented MPTP-induced depletion of striatal DA, and maintained striatal tyrosine hydroxylase (TH) protein levels. Our results also demonstrated that mice treated with resveratrol prior to MPTP administration showed more abundant TH-immunopositive neurons than mice given only MPTP, indicating that resveratrol protects nigral neurons from MPTP insults. Altogether, these data revealed that resveratrol can counteract the toxic effects of the neurotoxin MPTP and, as such, it may be regarded as a powerful molecule for complementary neuroprotective therapy.