Mitochondrial Homeostasis and Signaling in Parkinson's Disease

Pathogenesis of DJ-1/PARK7-Mediated Parkinson's Disease

Parkinson's disease (PD) is a common movement disorder associated with the degeneration of dopaminergic neurons in the substantia nigra pars compacta. Mutations in the PD-associated gene PARK7 alter the structure and function of the encoded protein DJ-1, and the resulting autosomal recessively inherited disease increases the risk of developing PD. DJ-1 was first discovered in 1997 as an oncogene and was associated with early-onset PD in 2003. Mutations in DJ-1 account for approximately 1% of all recessively inherited early-onset PD occurrences, and the functions of the protein have been studied extensively. In healthy subjects, DJ-1 acts as an antioxidant and oxidative stress sensor in several neuroprotective mechanisms. It is also involved in mitochondrial homeostasis, regulation of apoptosis, chaperone-mediated autophagy (CMA), and dopamine homeostasis by regulating various signaling pathways, transcription factors, and molecular chaperone functions. While DJ-1 protects neurons against damaging reactive oxygen species, neurotoxins, and mutant α-synuclein, mutations in the protein may lead to inefficient neuroprotection and the progression of PD. As current therapies treat only the symptoms of PD, the development of therapies that directly inhibit oxidative stress-induced neuronal cell death is critical. DJ-1 has been proposed as a potential therapeutic target, while oxidized DJ-1 could operate as a biomarker for PD. In this paper, we review the role of DJ-1 in the pathogenesis of PD by highlighting some of its key neuroprotective functions and the consequences of its dysfunction.

Research progress in the molecular mechanism of ferroptosis in Parkinson's disease and regulation by natural plant products

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder of the central nervous system after Alzheimer's disease. The current understanding of PD focuses mainly on the loss of dopamine neurons in the substantia nigra region of the midbrain, which is attributed to factors such as oxidative stress, alpha-synuclein aggregation, neuroinflammation, and mitochondrial dysfunction. These factors together contribute to the PD phenotype. Recent studies on PD pathology have introduced a new form of cell death known as ferroptosis. Pathological changes closely linked with ferroptosis have been seen in the brain tissues of PD patients, including alterations in iron metabolism, lipid peroxidation, and increased levels of reactive oxygen species. Preclinical research has demonstrated the neuroprotective qualities of certain iron chelators, antioxidants, Fer-1, and conditioners in Parkinson's disease. Natural plant products have shown significant potential in balancing ferroptosis-related factors and adjusting their expression levels. Therefore, it is vital to understand the mechanisms by which natural plant products inhibit ferroptosis and relieve PD symptoms. This review provides a comprehensive look at ferroptosis, its role in PD pathology, and the mechanisms underlying the therapeutic effects of natural plant products focused on ferroptosis. The insights from this review can serve as useful references for future research on novel ferroptosis inhibitors and lead compounds for PD treatment.

Low-dose Cu exposure enhanced α-synuclein accumulation associates with mitochondrial impairments in mice model of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder that mainly affects the elder population, and its etiology is enigmatic. Both environmental risks and genetics may influence the development of PD. Excess copper causes neurotoxicity and accelerates the progression of neurodegenerative diseases. However, the underlying mechanisms of copper-induced neurotoxicity remain controversial. In this study, A53T transgenic α-synuclein (A53T) mice and their matching wild-type (WT) mice were treated with a low dose of copper (0.13 ppm copper chlorinated drinking water, equivalent to the copper exposure of human daily copper intake dose) for 4 months, and copper poisoning was performed on human A53T mutant SHSY5Y cells overexpressed with α-synuclein (dose of 1/4 IC50), to test the effects of copper exposure on the body. The results of the open field test showed that the moto function of Cu-treated mice was impaired. Proteomics revealed changes in neurodevelopment, transport function, and mitochondrial membrane-related function in Cu-treated WT mice, which were associated with reduced expression of mitochondrial complex (NDUFA10, ATP5A), dopamine neurons (TH), and dopamine transporter (DAT). Mitochondrial function, nervous system development, synaptic function, and immune response were altered in Cu-treated A53T mice. These changes were associated with increased mitochondrial splitting protein (Drp1), decreased mitochondrial fusion protein (OPA1, Mfn1), abnormalities in mitochondrial autophagy protein (LC3BII/I, P62), decreased dopamine neuron (TH) expression, increased α-synuclein expression, inflammatory factors (IL-6, IL-1β, and TNF-α) release and microglia (Iba1) activation. In addition, we found that Cu2+ (30 μM) induced excessive ROS production and reduced mitochondrial ATP production in human A53T mutant α-synuclein overexpressing SHSY5Y cells by in vitro experiments. In conclusion, low-dose copper treatment altered critical proteins involved in mitochondrial, neurodevelopmental, and inflammatory responses and affected mitochondria's ROS and ATP production levels.

Escalating Bi-Directional Feedback Loops between Proinflammatory Microglia and Mitochondria in Ageing and Post-Diagnosis of Parkinson's Disease

Parkinson's disease (PD) is a chronic and progressive age-related neurodegenerative disease affecting up to 3% of the global population over 65 years of age. Currently, the underlying physiological aetiology of PD is unknown. However, the diagnosed disorder shares many common non-motor symptoms associated with ageing-related neurodegenerative disease progression, such as neuroinflammation, microglial activation, neuronal mitochondrial impairment, and chronic autonomic nervous system dysfunction. Clinical PD has been linked to many interrelated biological and molecular processes, such as escalating proinflammatory immune responses, mitochondrial impairment, lower adenosine triphosphate (ATP) availability, increasing release of neurotoxic reactive oxygen species (ROS), impaired blood brain barrier integrity, chronic activation of microglia, and damage to dopaminergic neurons consistently associated with motor and cognitive decline. Prodromal PD has also been associated with orthostatic hypotension and many other age-related impairments, such as sleep disruption, impaired gut microbiome, and constipation. Thus, this review aimed to present evidence linking mitochondrial dysfunction, including elevated oxidative stress, ROS, and impaired cellular energy production, with the overactivation and escalation of a microglial-mediated proinflammatory immune response as naturally occurring and damaging interlinked bidirectional and self-perpetuating cycles that share common pathological processes in ageing and PD. We propose that both chronic inflammation, microglial activation, and neuronal mitochondrial impairment should be considered as concurrently influencing each other along a continuum rather than as separate and isolated linear metabolic events that affect specific aspects of neural processing and brain function.

3D biocomposite culture enhances differentiation of dopamine-like neurons from SH-SY5Y cells: A model for studying Parkinson's disease phenotypes

Studies of underlying neurodegenerative processes in Parkinson's Disease (PD) have traditionally utilized cell cultures grown on two-dimensional (2D) surfaces. Biomimetic three-dimensional (3D) cell culture platforms have been developed to better emulate features of the brain's natural microenvironment. We here use our bioengineered brain-like tissue model, composed of a silk-hydrogel composite, to study the 3D microenvironment's contributions on the development and performance of dopaminergic-like neurons (DLNs). Compared with 2D culture, SH-SY5Y cells differentiated in 3D microenvironments were enriched for DLNs concomitant with a reduction in proliferative capacity during the neurodevelopmental process. Additionally, the 3D DLN cultures were more sensitive to oxidative stresses elicited by the PD-related neurotoxin 1-methyl-4-phenylpyridinium (MPP). MPP induced transcriptomic profile changes specific to 3D-differentiated DLN cultures, replicating the dysfunction of neuronal signaling pathways and mitochondrial dynamics implicated in PD. Overall, this physiologically-relevant 3D platform resembles a useful tool for studying dopamine neuron biology and interrogating molecular mechanisms underlying neurodegeneration in PD.

Effects of high glutamate concentrations on mitochondria of human neuroblastoma SH-SY5Y cells

BACKGROUND

The excess amount of glutamate in neurons is associated with the excitotoxicity and neurodegenerative diseases. Glutamate induces neurotoxicity primarily by immense influx of Ca²⁺ arising from overstimulation of the NMDA subtype of glutamate receptors. The neuronal death induced by the overstimulation of glutamate receptors depends critically on a sustained increase in mitochondrial Ca²⁺ influx and impairment in mitochondrial functions. The mitochondrial impairment is an important contributor to the glutamate-induced neuronal toxicity and thus provides an important target for the intervention. The present study investigates the effects of high glutamate concentrations on mitochondrial functions.

RESULTS

Here, we have shown that the higher concentration of glutamate treatment caused a significant elevation in the N-methyl-D-aspartate (NMDA) receptors expression and elevated the intra-mitochondrial calcium accumulation in SHSY5Y neuronal cells. As a result of an accumulation of intra-mitochondrial calcium, there is a concentration-dependent elevation in ROS in the mitochondria. Tyrosine nitration of several mitochondrial proteins was increased while the mitochondrial membrane potential was dissipated. Furthermore, glutamate treatments also resulted in mitochondrial membrane permeability transition.

CONCLUSIONS

These findings suggest that treatment of high glutamate concentration causes impairment of mitochondrial functions by an increase in intra-mitochondrial calcium, ROS production, dissipation of mitochondrial membrane potential and mitochondrial permeability transition pore opening in human neuroblastoma SHSY5Y cells.

Oxidative stress and synaptic dysfunction in rodent models of Parkinson's disease

Parkinson's disease (PD) is a multifactorial disorder involving a complex interplay between a variety of genetic and environmental factors. In this scenario, mitochondrial impairment and oxidative stress are widely accepted as crucial neuropathogenic mechanisms, as also evidenced by the identification of PD-associated genes that are directly involved in mitochondrial function. The concept of mitochondrial dysfunction is closely linked to that of synaptic dysfunction. Indeed, compelling evidence supports the role of mitochondria in synaptic transmission and plasticity, although many aspects have not yet been fully elucidated. Here, we will provide a brief overview of the most relevant evidence obtained in different neurotoxin-based and genetic rodent models of PD, focusing on mitochondrial impairment and synaptopathy, an early central event preceding overt nigrostriatal neurodegeneration. The identification of early deficits occurring in PD pathogenesis is crucial in view of the development of potential disease-modifying therapeutic strategies.

The multifaceted role of LRRK2 in Parkinson's disease: From human iPSC to organoids

Parkinson's disease (PD) is the second most common neurodegenerative disease affecting elderly people. Pathogenic mutations in Leucine-Rich Repeat Kinase 2 (LRRK2) are the most common cause of autosomal dominant PD. LRRK2 activity is enhanced in both familial and idiopathic PD, thereby studies on LRRK2-related PD research are essential for understanding PD pathology. Finding an appropriate model to mimic PD pathology is crucial for revealing the molecular mechanisms underlying disease progression, and aiding drug discovery. In the last few years, the use of human-induced pluripotent stem cells (hiPSCs) grew exponentially, especially in studying neurodegenerative diseases like PD, where working with brain neurons and glial cells was mainly possible using postmortem samples. In this review, we will discuss the use of hiPSCs as a model for PD pathology and research on the LRRK2 function in both neuronal and immune cells, together with reviewing the recent advances in 3D organoid models and microfluidics.

Targeting Mitochondria as a Therapeutic Approach for Parkinson's Disease

Neurodegeneration is among the most critical challenges that involve modern societies and annually influences millions of patients worldwide. While the pathophysiology of Parkinson's disease (PD) is complicated, the role of mitochondrial is demonstrated. The in vitro and in vivo models and genome-wide association studies in human cases proved that specific genes, including PINK1, Parkin, DJ-1, SNCA, and LRRK2, linked mitochondrial dysfunction with PD. Also, mitochondrial DNA (mtDNA) plays an essential role in the pathophysiology of PD. Targeting mitochondria as a therapeutic approach to inhibit or slow down PD formation and progression seems to be an exciting issue. The current review summarized known mutations associated with both mitochondrial dysfunction and PD. The significance of mtDNA in Parkinson's disease pathogenesis and potential PD therapeutic approaches targeting mitochondrial dysfunction was then discussed.

Effects of vitamin D (VD3) supplementation on the brain mitochondrial function of male rats, in the 6-OHDA-induced model of Parkinson's disease

Mitochondria dysfunction is an important factor involved in PD pathogenesis. We reported neuroprotective actions of vitamin D (VD3) on a PD model, and now we investigated the VD3 effects on the brain mitochondrial function. We focused on oxygen consumption, respiratory control ratio (RCR), ADP/O ratio, mitochondria swelling, H₂O₂ production, and SOD activity. Additionally, immunohistochemistry assays for the dopamine system markers (TH and DAT) and mitochondrial markers (VDAC1 and Hsp60) were also carried out in the striata. Young adult male Wistar rats (250 g, 2.5 months age) were anesthetized and subjected to stereotaxic surgery and injection of saline (SO group) or 6-OHDA, into the right striatum. Brain mitochondria were isolated from the groups: sham-operated (SO), 6-OHDA, 6-OHDA pretreated with VD3 for 7, days before the 6-OHDA lesion (6-OHDA+VD3, pre-) or treated with VD3 for 14 days, after the 6-OHDA lesion (6-OHDA+VD3, post-). VD3 prevented decreases in oxygen consumption, RCR, and ADP/O ratio observed after 6-OHDA injury. Noteworthy, a very low (oxygen consumption and RCR) or no improvement (ADP/O) were observed in the 6-OHDA+VD3 post- group. VD3 also prevented the increased mitochondria swelling and H₂O₂ production and a decrease in SOD activity, respectively, in the 6-OHDA injured mitochondria. Also, VD3 supplementation protected the hemiparkinsonian brain from decreases in TH and DAT expressions and decreased the upregulation of mitochondrial markers, as VDAC 1 and Hsp60. In conclusion, VD3 showed neuroprotective actions on brain mitochondria injured by 6-OHDA and should stimulate translational studies focusing on its use as a therapeutic strategy for the treatment of neurodegenerative diseases as PD.

Dopaminergic Axons: Key Recitalists in Parkinson's Disease

Parkinson's disease (PD) is associated with dopamine depletion in the striatum owing to the selective and progressive loss of the nigrostriatal dopaminergic neurons, which results in motor dysfunction and secondary clinical manifestations. The dopamine level in the striatum is preserved because of the innervation of the substantia nigra (SN) dopaminergic neurons into it. Therefore, protection of the SN neurons is crucial for maintaining the dopamine level in the striatum and for ensuring the desired motor coordination. Several strategies have been devised to protect the degenerating dopaminergic neurons or to restore the dopamine levels for treating PD. Most of the methods focus exclusively on preventing cell body death in the neurons. Although advances have been made in understanding the disease, the search for disease-modifying drugs is an ongoing process. The present review describes the evidence from studies involving patients with PD as well as PD models that axon terminals are highly vulnerable to exogenous and endogenous insults and degenerate at the early stage of the disease. Impairment of mitochondrial dynamics, Ca²⁺ homeostasis, axonal transport, and loss of plasticity of axon terminals appear before the neuronal degeneration in PD. Furthermore, distortion of synaptic morphology and reduction of postsynaptic dendritic spines are the neuropathological hallmarks of early-stage disease. Thus, the review proposes a shift in focus from discerning the mechanism of neuronal cell body loss and targeting it to an entirely different approach of preventing axonal degeneration. The review also suggests appropriate strategies to prevent the loss of synaptic terminals, which could induce regrowth of the axon and its auxiliary fibers and might offer relief from the symptomatic features of PD.

Ncx3-Induced Mitochondrial Dysfunction in Midbrain Leads to Neuroinflammation in Striatum of A53t-α-Synuclein Transgenic Old Mice

The exact mechanism underlying selective dopaminergic neurodegeneration is not completely understood. The complex interplay among toxic alpha-synuclein aggregates, oxidative stress, altered intracellular Ca²⁺-homeostasis, mitochondrial dysfunction and disruption of mitochondrial integrity is considered among the pathogenic mechanisms leading to dopaminergic neuronal loss. We herein investigated the molecular mechanisms leading to mitochondrial dysfunction and its relationship with activation of the neuroinflammatory process occurring in Parkinson’s disease. To address these issues, experiments were performed in vitro and in vivo in mice carrying the human mutation of α-synuclein A53T under the prion murine promoter. In these models, the expression and activity of NCX isoforms, a family of important transporters regulating ionic homeostasis in mammalian cells working in a bidirectional way, were evaluated in neurons and glial cells. Mitochondrial function was monitored with confocal microscopy and fluorescent dyes to measure mitochondrial calcium content and mitochondrial membrane potential. Parallel experiments were performed in 4 and 16-month-old A53T-α-synuclein Tg mice to correlate the functional data obtained in vitro with mitochondrial dysfunction and neuroinflammation through biochemical analysis. The results obtained demonstrated: 1. in A53T mice mitochondrial dysfunction occurs early in midbrain and later in striatum; 2. mitochondrial dysfunction occurring in the midbrain is mediated by the impairment of NCX3 protein expression in neurons and astrocytes; 3. mitochondrial dysfunction occurring early in midbrain triggers neuroinflammation later into the striatum, thus contributing to PD progression during mice aging.

Mitochondrial Ca2+ Signaling in Health, Disease and Therapy

The divalent cation calcium (Ca²⁺) is considered one of the main second messengers inside cells and acts as the most prominent signal in a plethora of biological processes. Its homeostasis is guaranteed by an intricate and complex system of channels, pumps, and exchangers. In this context, by regulating cellular Ca²⁺ levels, mitochondria control both the uptake and release of Ca²⁺. Therefore, at the mitochondrial level, Ca²⁺ plays a dual role, participating in both vital physiological processes (ATP production and regulation of mitochondrial metabolism) and pathophysiological processes (cell death, cancer progression and metastasis). Hence, it is not surprising that alterations in mitochondrial Ca²⁺ (mCa²⁺) pathways or mutations in Ca²⁺ transporters affect the activities and functions of the entire cell. Indeed, it is widely recognized that dysregulation of mCa²⁺ signaling leads to various pathological scenarios, including cancer, neurological defects and cardiovascular diseases (CVDs). This review summarizes the current knowledge on the regulation of mCa²⁺ homeostasis, the related mechanisms and the significance of this regulation in physiology and human diseases. We also highlight strategies aimed at remedying mCa²⁺ dysregulation as promising therapeutical approaches.

Involvement of the Protein Ras Homolog Enriched in the Striatum, Rhes, in Dopaminergic Neurons' Degeneration: Link to Parkinson's Disease

Rhes is one of the most interesting genes regulated by thyroid hormones that, through the inhibition of the striatal cAMP/PKA pathway, acts as a modulator of dopamine neurotransmission. Rhes mRNA is expressed at high levels in the dorsal striatum, with a medial-to-lateral expression gradient reflecting that of both dopamine D₂ and adenosine A_2A receptors. Rhes transcript is also present in the hippocampus, cerebral cortex, olfactory tubercle and bulb, substantia nigra pars compacta (SNc) and ventral tegmental area of the rodent brain. In line with Rhes-dependent regulation of dopaminergic transmission, data showed that lack of Rhes enhanced cocaine- and amphetamine-induced motor stimulation in mice. Previous studies showed that pharmacological depletion of dopamine significantly reduces Rhes mRNA levels in rodents, non-human primates and Parkinson's disease (PD) patients, suggesting a link between dopaminergic innervation and physiological Rhes mRNA expression. Rhes protein binds to and activates striatal mTORC1, and modulates L-DOPA-induced dyskinesia in PD rodent models. Finally, Rhes is involved in the survival of mouse midbrain dopaminergic neurons of SNc, thus pointing towards a Rhes-dependent modulation of autophagy and mitophagy processes, and encouraging further investigations about mechanisms underlying dysfunctions of the nigrostriatal system.

DNA Methylation and Expression Profiles of Whole Blood in Parkinson's Disease

Parkinson’s disease (PD) is the second most common age-related neurodegenerative disease. It is presently only accurately diagnosed at an advanced stage by a series of motor deficits, which are predated by a litany of non-motor symptoms manifesting over years or decades. Aberrant epigenetic modifications exist across a range of diseases and are non-invasively detectable in blood as potential markers of disease. We performed comparative analyses of the methylome and transcriptome in blood from PD patients and matched controls. Our aim was to characterize DNA methylation and gene expression patterns in whole blood from PD patients as a foundational step toward the future goal of identifying molecular markers that could predict, accurately diagnose, or track the progression of PD. We found that differentially expressed genes (DEGs) were involved in the processes of transcription and mitochondrial function and that PD methylation profiles were readily distinguishable from healthy controls, even in whole-blood DNA samples. Differentially methylated regions (DMRs) were functionally varied, including near transcription factor nuclear transcription factor Y subunit alpha (NFYA), receptor tyrosine kinase DDR1, RING finger ubiquitin ligase (RNF5), acetyltransferase AGPAT1, and vault RNA VTRNA2-1. Expression quantitative trait methylation sites were found at long non-coding RNA PAX8-AS1 and transcription regulator ZFP57 among others. Functional epigenetic modules were highlighted by IL18R1, PTPRC, and ITGB2. We identified patterns of altered disease-specific DNA methylation and associated gene expression in whole blood. Our combined analyses extended what we learned from the DEG or DMR results alone. These studies provide a foundation to support the characterization of larger sample cohorts, with the goal of building a thorough, accurate, and non-invasive molecular PD biomarker.

The Promise of the Zebrafish Model for Parkinson's Disease: Today's Science and Tomorrow's Treatment

The second most prevalent neurodegenerative disorder in the elderly is Parkinson's disease (PD). Its etiology is unclear and there are no available disease-modifying medicines. Therefore, more evidence is required concerning its pathogenesis. The use of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is the basis of most animal models of PD. MPTP is metabolized by monoamine oxidase B (MAO B) to MPP + and induces the loss of dopaminergic neurons in the substantia nigra in mammals. Zebrafish have been commonly used in developmental biology as a model organism, but owing to its perfect mix of properties, it is now emerging as a model for human diseases. Zebrafish (Danio rerio) are cheap and easy to sustain, evolve rapidly, breed transparent embryos in large amounts, and are readily manipulated by different methods, particularly genetic ones. Furthermore, zebrafish are vertebrate species and mammalian findings obtained from zebrafish may be more applicable than those derived from genetic models of invertebrates such as Drosophila melanogaster and Caenorhabditis elegans. The resemblance cannot be taken for granted, however. The goal of the present review article is to highlight the promise of zebrafish as a PD animal model. As its aminergic structures, MPTP mode of action, and PINK1 roles mimic those of mammalians, zebrafish seems to be a viable model for studying PD. The roles of zebrafish MAO, however, vary from those of the two types of MAO present in mammals. The benefits unique to zebrafish, such as the ability to perform large-scale genetic or drug screens, should be exploited in future experiments utilizing zebrafish PD models.

Elucidating the Multi-Targeted Role of Nutraceuticals: A Complementary Therapy to Starve Neurodegenerative Diseases

The mechanisms underlying multifactorial diseases are always complex and challenging. Neurodegenerative disorders (NDs) are common around the globe, posing a critical healthcare issue and financial burden to the country. However, integrative evidence implies some common shared mechanisms and pathways in NDs, which include mitochondrial dysfunction, neuroinflammation, oxidative stress, intracellular calcium overload, protein aggregates, oxidative stress (OS), and neuronal destruction in specific regions of the brain, owing to multifaceted pathologies. The co-existence of these multiple pathways often limits the advantages of available therapies. The nutraceutical-based approach has opened the doors to target these common multifaceted pathways in a slow and more physiological manner to starve the NDs. Peer-reviewed articles were searched via MEDLINE and PubMed published to date for in-depth research and database collection. Considered to be complementary therapy with current clinical management and common drug therapy, the intake of nutraceuticals is considered safe to target multiple mechanisms of action in NDs. The current review summarizes the popular nutraceuticals showing different effects (anti-inflammatory, antioxidant, neuro-protectant, mitochondrial homeostasis, neurogenesis promotion, and autophagy regulation) on vital molecular mechanisms involved in NDs, which can be considered as complementary therapy to first-line treatment. Moreover, owing to its natural source, lower toxicity, therapeutic interventions, biocompatibility, potential nutritional effects, and presence of various anti-oxidative and neuroprotective constituents, the nutraceuticals serve as an attractive option to tackle NDs.

Potential therapeutic applications of AKAP disrupting peptides

The 3'-5'-cyclic adenosine monophosphate (cAMP)/PKA pathway represents a major target for pharmacological intervention in multiple disease conditions. Although the last decade saw the concept of highly compartmentalized cAMP/PKA signaling consolidating, current means for the manipulation of this pathway still do not allow to specifically intervene on discrete cAMP/PKA microdomains. Since compartmentalization is crucial for action specificity, identifying new tools that allow local modulation of cAMP/PKA responses is an urgent need. Among key players of cAMP/PKA signaling compartmentalization, a major role is played by A-kinase anchoring proteins (AKAPs) that, by definition, anchor PKA, its substrates and its regulators within multiprotein complexes in well-confined subcellular compartments. Different tools have been conceived to interfere with AKAP-based protein-protein interactions (PPIs), and these primarily include peptides and peptidomimetics that disrupt AKAP-directed multiprotein complexes. While these molecules have been extensively used to understand the molecular mechanisms behind AKAP function in pathophysiological processes, less attention has been devoted to their potential application for therapy. In this review, we will discuss how AKAP-based PPIs can be pharmacologically targeted by synthetic peptides and peptidomimetics.

Fermented Soy Products: Beneficial Potential in Neurodegenerative Diseases

Fermented soybean products, such as cheonggukjang (Japanese natto), doenjang (soy paste), ganjang (soy sauce), and douchi, are widely consumed in East Asian countries and are major sources of bioactive compounds. The fermentation of cooked soybean with bacteria (Bacillus spp.) and fungi (Aspergillus spp. and Rhizopus spp.) produces a variety of novel compounds, most of which possess health benefits. This review is focused on the preventive and ameliorative potential of fermented soy foods and their components to manage neurodegenerative diseases, including Alzheimer's and Parkinson's diseases.

Autophagy and Autophagy-Related Diseases: A Review

Autophagy refers to the process involving the decomposition of intracellular components via lysosomes. Autophagy plays an important role in maintaining and regulating cell homeostasis by degrading intracellular components and providing degradation products to cells. In vivo, autophagy has been shown to be involved in the starvation response, intracellular quality control, early development, and cell differentiation. Recent studies have revealed that autophagy dysfunction is implicated in neurodegenerative diseases and tumorigenesis. In addition to the discovery of certain disease-causing autophagy-related mutations and elucidation of the pathogenesis of conditions resulting from the abnormal degradation of selective autophagy substrates, the activation of autophagy is essential for prolonging life and suppressing aging. This article provides a comprehensive review of the role of autophagy in health, physiological function, and autophagy-related disease.

Gateways for Glutamate Neuroprotection in Parkinson's Disease (PD): Essential Role of EAAT3 and NCX1 Revealed in an In Vitro Model of PD

Increasing evidence suggests that metabolic alterations may be etiologically linked to neurodegenerative disorders such as Parkinson's disease (PD) and in particular empathizes the possibility of targeting mitochondrial dysfunctions to improve PD progression. Under different pathological conditions (i.e., cardiac and neuronal ischemia/reperfusion injury), we showed that supplementation of energetic substrates like glutamate exerts a protective role by preserving mitochondrial functions and enhancing ATP synthesis through a mechanism involving the Na⁺-dependent excitatory amino acid transporters (EAATs) and the Na⁺/Ca²⁺ exchanger (NCX). In this study, we investigated whether a similar approach aimed at promoting glutamate metabolism would be also beneficial against cell damage in an in vitro PD-like model. In retinoic acid (RA)-differentiated SH-SY5Y cells challenged with α-synuclein (α-syn) plus rotenone (Rot), glutamate significantly improved cell viability by increasing ATP levels, reducing oxidative damage and cytosolic and mitochondrial Ca²⁺ overload. Glutamate benefits were strikingly lost when either EAAT3 or NCX1 expression was knocked down by RNA silencing. Overall, our results open the possibility of targeting EAAT3/NCX1 functions to limit PD pathology by simultaneously favoring glutamate uptake and metabolic use in dopaminergic neurons.