Neurotrophic factors in Alzheimer's and Parkinson's disease brain

Advances in nanotechnology-assisted photodynamic therapy for neurological disorders: a comprehensive review

Neurological disorders such as neurodegenerative diseases and nervous system tumours affect more than one billion people throughout the globe. The physiological sensitivity of the nervous tissue limits the application of invasive therapies and leads to poor treatment and prognosis. One promising solution that has generated attention is Photodynamic therapy (PDT), which can potentially revolutionise the treatment landscape for neurological disorders. PDT attracted substantial recognition for anticancer efficacy and drug conjugation for targeted drug delivery. This review thoroughly explained the basic principles of PDT, scientific interventions and advances in PDT, and their complicated mechanism in treating brain-related pathologies. Furthermore, the merits and demerits of PDT in the context of neurological disorders offer a well-rounded perspective on its feasibility and challenges. In conclusion, this review encapsulates the significant potential of PDT in transforming the treatment landscape for neurological disorders, emphasising its role as a non-invasive, targeted therapeutic approach with multifaceted applications.

Intranasal delivery of liposome encapsulated flavonoids ameliorates l-DOPA induced dyskinesia in hemiparkinsonian mice

In the present study, we explored the development of a novel noninvasive liposomal drug delivery material for use in intranasal drug delivery applications in human diseases. We used drug entrapment into liposomal nanoparticle assembly to efficiently deliver the drugs to the nasal mucosa to be delivered to the brain. The naturally occurring flavonoid 7,8-dihydroxyflavone (7,8-DHF) has previously been shown to have beneficial effects in ameliorating Parkinson's disease (PD). We used both naturally occurring 7,8-DHF and the chemically modified form of DHF, the DHF-ME, to be used as a drug candidate for the treatment of PD and l-DOPA induced dyskinesia (LID), which is the debilitating side effect of l-DOPA therapy in PD. The ligand-protein interaction behavior for 7,8-DHF and 6,7-DHF-ME was found to be more effective with molecular docking and molecular stimulation studies of flavonoid compounds with TrkB receptor. Our study showed that 7,8-DHF delivered via intranasal route using a liposomal formulation ameliorated LID in hemiparkinsonian mice model when these mice were chronically administered with l-DOPA, which is the only current medication for relieving the clinical symptoms of PD. The present study also demonstrated that apart from reducing the LID, 7,8-DHF delivery directly to the brain via the intranasal route also corrected some long-term signaling adaptations involving ΔFosB and α Synuclein in the brain of dopamine (DA) depleted animals.

Ginsenoside Rg3 Restores Mitochondrial Cardiolipin Homeostasis via GRB2 to Prevent Parkinson's Disease

Regulating cardiolipin to maintain mitochondrial homeostasis is a promising strategy for addressing Parkinson's disease (PD). Through a comprehensive screening and validation process involving multiple models, ginsenoside Rg3 (Rg3) as a compound capable of enhancing cardiolipin levels is identified. This augmentation in cardiolipin levels fosters mitochondrial homeostasis by bolstering mitochondrial unfolded protein response, promoting mitophagy, and enhancing mitochondrial oxidative phosphorylation. Consequently, this cascade enhances the survival of tyrosine hydroxylase positive (TH+) dopaminergic neurons, leading to an amelioration in motor performance within PD mouse models. Using limited proteolysis-small-molecule mapping combined with molecular docking analysis, it has confirmed Growth Factor Receptor-Bound Protein 2 (GRB2) as a molecular target for Rg3. Furthermore, these investigations reveal that Rg3 facilitates the interaction between GRB2 and TRKA (Neurotrophic Tyrosine Kinase, Receptor, Type 1), thus promotes EVI1 (Ecotropic Virus Integration Site 1 Protein Homolog) phosphorylation by ERK, subsequently increases CRLS1 (Cardiolipin Synthase 1) gene expression and boosts cardiolipin synthesis. The absence of GRB2 or CRLS1 significantly attenuates the beneficial effects of Rg3 on PD symptoms. Finally, Tenofovir Disoproxil Fumarate (TDF) that also promotes the binding between GRB2 and TRKA is further identified. The identified compounds, Rg3 and TDF, exhibit promising potential for the prevention of PD by bolstering cardiolipin expression and reinstating mitochondrial homeostasis.

The seeds of its regulation: Natural antisense transcripts as single-gene control switches in neurodegenerative disorders

Several proteins play critical roles in vulnerability or resistance to neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), and frontotemporal dementia (FTD). Regulation of these proteins is critical to maintaining healthy neurohomeostasis. In addition to transcription factors regulating gene transcription and microRNAs regulating mRNA translation, natural antisense transcripts (NATs) regulate mRNA levels, splicing, and translation. NATs' roles are significant in regulating key protein-coding genes associated with neurodegenerative disorders. Elucidating the functions of these NATs could prove useful in treating or preventing diseases. NAT activity is not restricted to mRNA translation; it can also regulate DNA (de)methylation and other gene expression steps. NATs are noncoding RNAs (ncRNAs) encoded by DNA sequences overlapping the pertinent protein genes. These NATs have complex structures, including introns and exons, and therefore bind their target genes, precursor mRNAs (pre-mRNAs), and mature RNAs. They can occur at the 5'- or 3'-ends of a mRNA-coding sequence or internally to a parent gene. NATs can downregulate translation, e.g., microtubule-associated protein tau (MAPT) antisense-1 gene (MAPT-AS1), or upregulate translation, e.g., β-Amyloid site Cleaving Enzyme 1 (BACE1) antisense gene (BACE1-AS). Regulation of NATs can parallel pathogenesis, wherein a "pathogenic" NAT (e.g., BACE1-AS) is upregulated under pathogenic conditions, while a "protective" NAT (e.g., MAPT-AS1) is downregulated under pathogenic conditions. As a relatively underexplored endogenous control mechanism of protein expression, NATs may present novel mechanistic targets to prevent or ameliorate aging-related disorders.

The Potential of Metabolomics to Find Proper Biomarkers for Addressing the Neuroprotective Efficacy of Drugs Aimed at Delaying Parkinson's and Alzheimer's Disease Progression

The first objective is to highlight the lack of tools to measure whether a given intervention affords neuroprotection in patients with Alzheimer's or Parkinson's diseases. A second aim is to present the primary outcome measures used in clinical trials in cohorts of patients with neurodegenerative diseases. The final aim is to discuss whether metabolomics using body fluids may lead to the discovery of biomarkers of neuroprotection. Information on the primary outcome measures in clinical trials related to Alzheimer's and Parkinson's disease registered since 2018 was collected. We analysed the type of measures selected to assess efficacy, not in terms of neuroprotection since, as stated in the aims, there is not yet any marker of neuroprotection. Proteomic approaches using plasma or CSF have been proposed. PET could estimate the extent of lesions, but disease progression does not necessarily correlate with a change in tracer uptake. We propose some alternatives based on considering the metabolome. A new opportunity opens with metabolomics because there have been impressive technological advances that allow the detection, among others, of metabolites related to mitochondrial function and mitochondrial structure in serum and/or cerebrospinal fluid; some of the differentially concentrated metabolites can become reliable biomarkers of neuroprotection.

Navβ2 Intracellular Fragments Contribute to Aβ1-42-Induced Cognitive Impairment and Synaptic Deficit Through Transcriptional Suppression of BDNF

A pathological hallmark of Alzheimer's disease (AD) is the region-specific accumulation of the amyloid-beta protein (Aβ), which triggers aberrant neuronal excitability, synaptic impairment, and progressive cognitive decline. Previous works have demonstrated that Aβ pathology induced aberrant elevation in the levels and excessive enzymatic hydrolysis of voltage-gated sodium channel type 2 beta subunit (Navβ2) in the brain of AD models, accompanied by alteration in excitability of hippocampal neurons, synaptic deficits, and subsequently, cognitive dysfunction. However, the mechanism is unclear. In this research, by employing cell models treated with toxic Aβ1-42 and AD mice, the possible effects and potential mechanisms induced by Navβ2. The results reveal that Aβ1-42 induces remarkable increases in Navβ2 intracellular domain (Navβ2-ICD) and decreases in both BDNF exons and protein levels, as well as phosphorylated tropomyosin-related kinase B (pTrkB) expression in cells and mice, coupled with cognitive impairments, synaptic deficits, and aberrant neuronal excitability. Administration with exogenous Navβ2-ICD further enhances these effects induced by Aβ1-42, while interfering the generation of Navβ2-ICD and/or complementing BDNF neutralize the Navβ2-ICD-conducted effects. Luciferase reporter assay verifies that Navβ2-ICD regulates BDNF transcription and expression by targeting its promoter. Collectively, our findings partially elucidate that abnormal enzymatic hydrolysis of Navβ2 induced by Aβ1-42-associated AD pathology leads to intracellular Navβ2-ICD overload, which may responsible to abnormal neuronal excitability, synaptic deficit, and cognition dysfunction, through its transcriptional suppression on BDNF. Therefore, this work supplies novel evidences that Navβ2 plays crucial roles in the occurrence and progression of cognitive impairment of AD by transcriptional regulatory activity of its cleaved ICD.

The Molecular Pathway of p75 Neurotrophin Receptor (p75NTR) in Parkinson's Disease: The Way of New Inroads

Parkinson's disease (PD) is a chronic and progressive neurodegenerative disease of the brain. PD is characterized by motor and non-motor symptoms. The p75 neurotrophin receptor (p75NTR) is a functional receptor for different growth factors including pro-brain derived neurotrophic factor (pro-BDNF), neurotrophin 3 (NT-3), and neurotrophin 4 (NT-4). Consequently, this review aimed to illustrate the detrimental and beneficial role of p75NTR in PD. Diverse studies showed that p75NTR and its downstream signaling are intricate in the pathogenesis of PD. Nevertheless, pro-apoptotic and pro-survival pathways mediated by p75NTR in PD were not fully clarified. Of note, p75NTR plays a critical role in the regulation of dopaminergic neuronal survival and apoptosis in the CNS. Particularly, p75NTR can induce selective apoptosis of dopaminergic neurons and progression of PD. In addition, p75NTR signaling inhibits the expression of transcription factors which are essential for the survival of dopaminergic neurons. Also, p75NTR expression is connected with the severity of dopaminergic neuronal injury. These verdicts implicate p75NTR signaling in the pathogenesis of PD, though the underlying mechanistic pathways remain not elucidated. Collectively, the p75NTR signaling pathway induces a double-sword effect either detrimental or beneficial depending on the ligands and status of PD neuropathology. Therefore, p75NTR signaling seems to be protective via phosphoinositide 3-kinase (PI3K)/AKT and Bcl-2 and harmful via activation of JNK, caspase 3, nuclear factor kappa B (NF-κB), and RhoA pathways.

Neurotoxic Microglial Activation via IFNγ-Induced Nrf2 Reduction Exacerbating Alzheimer's Disease

Microglial neuroinflammation appears to be neuroprotective in the early pathological stage, yet neurotoxic, which often precedes neurodegeneration in Alzheimer's disease (AD). However, it remains unclear how the microglial activities transit to the neurotoxic state during AD progression, due to complex neuron-glia interactions. Here, the mechanism of detrimental microgliosis in AD by employing 3D human AD mini-brains, brain tissues of AD patients, and 5XFAD mice is explored. In the human and animal AD models, amyloid-beta (Aβ)-overexpressing neurons and reactive astrocytes produce interferon-gamma (IFNγ) and excessive oxidative stress. IFNγ results in the downregulation of mitogen-activated protein kinase (MAPK) and the upregulation of Kelch-like ECH-associated Protein 1 (Keap1) in microglia, which inactivate nuclear factor erythroid-2-related factor 2 (Nrf2) and sensitize microglia to the oxidative stress and induces a proinflammatory microglia via nuclear factor kappa B (NFκB)-axis. The proinflammatory microglia in turn produce neurotoxic nitric oxide and proinflammatory mediators exacerbating synaptic impairment, phosphorylated-tau accumulation, and discernable neuronal loss. Interestingly, recovering Nrf2 in the microglia prevents the activation of proinflammatory microglia and significantly blocks the tauopathy in AD minibrains. Taken together, it is envisioned that IFNγ-driven Nrf2 downregulation in microglia as a key target to ameliorate AD pathology.

3-Amino-5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carbonitrile: A fluorescent molecule that induces differentiation in PC12 cells

Neural differentiation is triggered by the activation of multiple signaling pathways initiated by various neurotrophic factors. An elucidation of these mechanisms is anticipated to facilitate the prevention of diseases and the development of novel therapeutic approaches. Alternative small-molecule inducers for neuroscience studies are required instead of protein-based reagents for more efficient and convenient experiments. We demonstrated that small molecules of thieno[2,3-b]pyridine derivatives that induce neural differentiation, compounds 3a and 9a in particular, exhibited significant neuritogenic activity in rat pheochromocytoma (PC12) cells. Moreover, 3a displayed pronounced fluorescence and a discernible Stokes shift. Furthermore, the outcome of the experiment conducted on the NGF-insensitive clones of rat PC12 cells, and the results of the intercellular uptake analyses suggested that the 3a-mediated activation of neural differentiation occurred independently of the TrkA receptor. Therefore, 3a portrays potential applicability both as a small molecule reagent to replace novel neurotrophic factors and as a potent fluorescent reagent for various techniques, including bioimaging.

The significance of glial cell line-derived neurotrophic factor analysis in Progressive Supranuclear Palsy

Progressive Supranuclear Palsy (PSP) is an atypical parkinsonism. Major subtypes of the disease: PSP-Richardson's Syndrome (PSP-RS) and PSP Parkinsonism Predominant (PSP-P) vary in clinical features, the pathomechanism remains unexplored. The aim of this work is to analyze the relevance of glial cell line-derived neurotrophic factor (GDNF) evaluation in the serum and cerebrospinal fluid (CSF) in PSP subtypes and to verify its significance as a possible factor in the in vivo examination. Authors assessed the concentration of GDNF in the serum and CSF of 12 patients with PSP-RS, 12 with PSP-P and 12 controls. Additionally authors evaluated patients using Unified Parkinson's Disease Rating Scale-III part (UPDRS-III), Frontal Assessment Battery (FAB) and Magnetic Resonance Imaging (MRI). The evaluation revealed significantly increased concentrations of GDNF in the CSF among PSP-RS patients and substantially increased concentrations of GDNF in the serum in PSP-P. Though the GDNF concentrations differentiated PSP subtypes, no correlations between with clinical factors were observed however certain correlations with atrophic changes in MRI were detected. GDNF is a factor which may impact the pathogenesis of PSP. Possible implementation of GDNF as a therapeutic factor could be a perspective in the search for therapy in this currently incurable disease.

Differential Regulation of Neurotrophic Factors During Pathogenic Tau-Aggregation in a Tau Transgenic Mouse Model for Alzheimer's Disease: A Protocol for Double-Labeling mRNA by In Situ Hybridization and Protein Epitopes by Immunohistochemistry

Alzheimer's disease (AD), most tauopathies, and other neurodegenerative diseases are highly associated to impaired neurotrophin regulation and imbalanced neurotrophin transport and distribution. Neurotrophins are crucial for the survival and maintenance of distinct neuronal population therefore their supply is essential for a healthy brain. Tau phosphorylation occurs at different sites of the tau protein and some phospho-epitopes are highly associated to AD (e.g., abnormally phosphorylated tau at Thr212/Ser214). Though the importance of neurotrophins is well known, their analysis in tissue is not trivial and needs careful consideration. Here a detailed protocol is presented, which combines in situ hybridization (ISH) with immunohistochemistry (IHC) to analyze neurotrophin mRNA expression during tau neuropathology and the results were confirmed by immunological methods.With this protocol, it was demonstrated that Brain-Derived Neurotrophic Factor (BDNF) and its receptor Tropomyosin receptor kinase B (TrkB) were significantly decreased in tau-transgenic mice compared to their age-matched littermates. Neurotrophin-3 (NT-3) and its receptor TrkC were not altered with statistical significance, but a tendency for decreased NT-3 and slightly increased TrkC expression was observed in tau transgenic mice. The loss of BDNF-ISH signal was predominantly observed in hippocampus (CA1 and CA3) and cortex (layer II-VI) and verified by BDNF-immunoreactivity. Decreased BDNF and TrkB mRNA was negatively correlated with abnormal tau phosphorylation at Thr212/Ser214 in cortical neurons in transgenic mice. Strikingly, no correlation was observed with age-related phospho-epitopes such as Ser202/Thr205. Interestingly, both, the mRNA and protein levels of Nerve Growth Factor (NGF) were significantly increased in hippocampal neurons in the tau models as demonstrated by ISH, immunofluorescence, and Western Blotting. Here, some co-localization of NGF mRNA and phospho-tau (Thr212/Ser214) was observed but was a rare event. Since there is growing evidence for the relevance of neurotrophic factor distribution in the pathogenesis of neurodegeneration, this technique is a useful tool to investigate the underlying mechanisms and potential therapeutic intervention.

New perspectives on the basal forebrain cholinergic system in Alzheimer's disease

The basal forebrain cholinergic system (BFCS) has long been implicated in age-related cognitive changes and the pathophysiology of Alzheimer's disease (AD). Limitations of cholinergic interventions helped to inspire a shift away from BFCS in AD research. A resurgence in interest in the BFCS following methodological and analytical advances has resulted in a call for the BFCS to be examined in novel frameworks. We outline the basic structure and function of the BFCS, its role in supporting cognitive and affective function, and its vulnerability to aging and AD. We consider the BFCS in the context of the amyloid hypothesis and evolving concepts in AD research: resilience and resistance to pathology, selective neuronal vulnerability, trans-synaptic pathology spread and sleep health. We highlight 1) the potential role of the BFCS in cognitive resilience, 2) recent work refining understanding about the selective vulnerability of BFCS to AD, 3) BFCS connectivity that suggests it is related to tau spreading and neurodegeneration and 4) the gap between BFCS involvement in AD and sleep-wake cycles.

GlyNAC (Glycine and N-Acetylcysteine) Supplementation in Old Mice Improves Brain Glutathione Deficiency, Oxidative Stress, Glucose Uptake, Mitochondrial Dysfunction, Genomic Damage, Inflammation and Neurotrophic Factors to Reverse Age-Associated Cognitive Decline: Implications for Improving Brain Health in Aging

Cognitive decline frequently occurs with increasing age, but mechanisms contributing to age-associated cognitive decline (ACD) are not well understood and solutions are lacking. Understanding and reversing mechanisms contributing to ACD are important because increased age is identified as the single most important risk factor for dementia. We reported earlier that ACD in older humans is associated with glutathione (GSH) deficiency, oxidative stress (OxS), mitochondrial dysfunction, glucose dysmetabolism and inflammation, and that supplementing GlyNAC (glycine and N-acetylcysteine) improved these defects. To test whether these defects occur in the brain in association with ACD, and could be improved/reversed with GlyNAC supplementation, we studied young (20-week) and old (90-week) C57BL/6J mice. Old mice received either regular or GlyNAC supplemented diets for 8 weeks, while young mice received the regular diet. Cognition and brain outcomes (GSH, OxS, mitochondrial energetics, autophagy/mitophagy, glucose transporters, inflammation, genomic damage and neurotrophic factors) were measured. Compared to young mice, the old-control mice had significant cognitive impairment and multiple brain defects. GlyNAC supplementation improved/corrected the brain defects and reversed ACD. This study finds that naturally-occurring ACD is associated with multiple abnormalities in the brain, and provides proof-of-concept that GlyNAC supplementation corrects these defects and improves cognitive function in aging.

Exploring the Therapeutic Effect of Neurotrophins and Neuropeptides in Neurodegenerative Diseases: at a Glance

Neurotrophins and neuropeptides are the essential regulators of peripheral nociceptive nerves that help to induce, sensitize, and maintain pain. Neuropeptide has a neuroprotective impact as it increases trophic support, regulates calcium homeostasis, and reduces excitotoxicity and neuroinflammation. In contrast, neurotrophins target neurons afflicted by ischemia, epilepsy, depression, and eating disorders, among other neuropsychiatric conditions. Neurotrophins are reported to inhibit neuronal death. Strategies maintained for "brain-derived neurotrophic factor (BDNF) therapies" are to upregulate BDNF levels using the delivery of protein and genes or compounds that target BDNF production and boosting BDNF signals by expanding with BDNF mimetics. This review discusses the mechanisms of neurotrophins and neuropeptides against acute neural damage as well as highlighting neuropeptides as a potential therapeutic agent against Parkinson's disease (PD), Huntington's disease (HD), Alzheimer's disease (AD), and Machado-Joseph disease (MJD), the signaling pathways affected by neurotrophins and their receptors in both standard and diseased CNS systems, and future perspectives that can lead to the potent application of neurotrophins and neuropeptides in neurodegenerative diseases (NDs).

Serum brain-derived neurotrophic factor as diagnosis clue for Alzheimer's disease: A cross-sectional observational study in the elderly

Objective

Brain-derived neurotrophic factor (BDNF) has not been validated as a diagnostic marker for Alzheimer's disease (AD). To provide a different perspective, this study aimed to evaluate the relationship between serum levels of mature BDNF (mBDNF) and precursor BDNF (proBDNF) in AD and to investigate whether serum BDNF levels or the ratio of mBDNF levels to proBDNF levels (M/P) could be a valuable biomarker for determining the risk of AD in elderly individuals.

Method

A total of 126 subjects who met the inclusion criteria were assigned to either the AD group (n = 62) or the healthy control group (HC, n = 64) in this cross-sectional observationl study. Serum levels of mBDNF and proBDNF were measured using enzyme immunoassay kits. We analyzed the Mini-Mental State Examination (MMSE) scores from the two groups and examined the associations between AD and BDNF metabolism.

Results

The serum concentration of proBDNF was significantly higher in ADs (4140.937 pg/ml) than in HCs (2606.943 pg/ml; p < 0.01). The MMSE significantly correlated with proBDNF (p < 0.01, r = −0.686) and M/P (p < 0.01, r = 0.595) in all subjects. To determine the risk for AD, the area under the receiver operating characteristic curve was calculated, which was 0.896 (95% confidence interval 0.844–0.949) for proBDNF and 0.901 (95% 0.850–0.953) for proBDNF and M/P combined.

Conclusion

We observed a correlation between low serum proBDNF levels and higher MMSE scores in AD. The most effective diagnostic strategy was the combination of proBDNF and M/P, whereas mBDNF levels performed poorly when we evaluated the predictive model.

Difference in Methylation and Expression of Brain-Derived Neurotrophic Factor in Alzheimer's Disease and Mild Cognitive Impairment

Due to the increasing number of progressive dementias in the population, numerous studies are being conducted that seek to determine risk factors, biomarkers and pathological mechanisms that could help to differentiate between normal symptoms of aging, mild cognitive impairment (MCI) and dementia. The aim of this study was to investigate the possible association of levels of BDNF and COMT gene expression and methylation in peripheral blood cells with the development of Alzheimer's disease (AD). Our results revealed higher expression levels of BDNF (p < 0.001) in MCI subjects compared to individuals diagnosed with AD. However, no difference in COMT gene expression (p = 0.366) was detected. DNA methylation of the CpG islands and other sequences with potential effects on gene expression regulation revealed just one region (BDNF_9) in the BDNF gene (p = 0.078) with marginally lower levels of methylation in the AD compared to MCI subjects. Here, we show that the level of BDNF expression in the periphery is decreased in subjects with AD compared to individuals with MCI. The combined results from the gene expression analysis and DNA methylation analysis point to the potential of BDNF as a marker that could help distinguish between MCI and AD patients.

Compensatory cognition in neurological diseases and aging: A review of animal and human studies

Specialized individual circuits in the brain are recruited for specific functions. Interestingly, multiple neural circuitries continuously compete with each other to acquire the specialized function. However, the dominant among them compete and become the central neural network for that particular function. For example, the hippocampal principal neural circuitries are the dominant networks among many which are involved in learning processes. But, in the event of damage to the principal circuitry, many times, less dominant networks compensate for the primary network. This review highlights the psychopathologies of functional loss and the aspects of functional recuperation in the absence of the hippocampus.

Meloxicam Inhibits Apoptosis in Neurons by Deactivating Tumor Necrosis Factor Receptor Superfamily Member 25, Leading to the Decreased Cleavage of DNA Fragmentation Factor Subunit α in Alzheimer's Disease

Neuronal apoptosis is considered to be a critical cause of Alzheimer's disease (AD). Recently, meloxicam has shown neuroprotective effects; however, the inherent mechanisms are highly overlooked. Using APP/PS1 transgenic (Tg) mice as in vivo animal models, we found that meloxicam inhibits apoptosis in neurons by deactivating tumor necrosis factor receptor superfamily member 25 (TNFRSF25), leading to the suppression of the expression of fas-associated protein with death domain (FADD) and the cleavage of DNA fragmentation factor subunit α (DFFA) and cysteine aspartic acid protease-3 (caspase 3) via β-amyloid protein (Aβ)-depressing mechanisms. Moreover, the meloxicam treatment blocked the effects of β-amyloid protein oligomers (Aβo) on stimulating the synthesis of tumor necrosis factor α (TNF-α) and TNF-like ligand 1A (TL1A) in neuroblastoma (N) 2a cells. TNF-α and TL1A induce apoptosis in neurons via TNFR- and TNFRSF25-dependent caspase 3-activating mechanisms, respectively. Knocking down the expression of TNFRSF25 blocked the effects of TL1A on inducing apoptosis in neurons by deactivating the signaling cascades of FADD, caspase 3, and DFFA. Consistently, TNFRSF25 shRNA blocked the effects of Aβo on inducing neuronal apoptosis, which was corroborated by the efficacy of meloxicam in inhibiting Aβo-induced neuronal apoptosis. By ameliorating neuronal apoptosis, meloxicam improved memory loss in APP/PS1 Tg mice.

Ageing and the Autonomic Nervous System

The vertebrate nervous system is divided into central (CNS) and peripheral (PNS) components. In turn, the PNS is divided into the autonomic (ANS) and enteric (ENS) nervous systems. Ageing implicates time-related changes to anatomy and physiology in reducing organismal fitness. In the case of the CNS, there exists substantial experimental evidence of the effects of age on individual neuronal and glial function. Although many such changes have yet to be experimentally observed in the PNS, there is considerable evidence of the role of ageing in the decline of ANS function over time. As such, this chapter will argue that the ANS constitutes a paradigm for the physiological consequences of ageing, as well as for their clinical implications.

The LEISURE Study: A Longitudinal Randomized Controlled Trial Protocol for a Multi-Modal Lifestyle Intervention Study to Reduce Dementia Risk in Healthy Older Adults

Dementia is understood to arise from a mixed etiology, enveloping chronic inflammatory and vascular impacts on the brain, driven by a constellation of modifiable risk factors which are largely mediated by lifestyle-related behaviors. These risk factors manifest over a prolonged preclinical period and account for up to 40% of the population attributable risk for dementia, representing viable targets for early interventions aimed at abating disease onset and progression. Here we outline the protocol for a 12-week randomized control trial (RCT) of a multimodal Lifestyle Intervention Study for Dementia Risk Reduction (LEISURE), with longitudinal follow-up at 6-months and 24-months post-intervention. This trial integrates exercise, diet, sleep, and mindfulness to simultaneously target multiple different etiopathogenetic mechanisms and their interplay in a healthy older adult population (aged 50-85 years), and assesses dementia risk reduction as the primary endpoint. The LEISURE study is located in the Sunshine Coast region of Australia, which has one of the nation's highest proportions of adults aged over 50 years (36.4%), and corresponding dementia prevalence. This trial is novel in its inclusion of mindfulness and sleep as multidomain lifestyle targets, and in its comprehensive suite of secondary outcomes (based on psychological, physical health, sleep activity, and cognitive data) as well as exploratory neuroimaging (magnetic resonance imaging and electroencephalography) and molecular biology measures. These measures will provide greater insights into the brain-behavioral underpinnings of dementia prevention, as well as the predictors and impacts of the proposed lifestyle intervention. The LEISURE study was prospectively registered (ACTRN12620000054910) on 19 January 2020.

The Polyunsaturated Fatty Acid EPA, but Not DHA, Enhances Neurotrophic Factor Expression through Epigenetic Mechanisms and Protects against Parkinsonian Neuronal Cell Death

ω-3 Polyunsaturated fatty acids (PUFAs) have been found to exert many actions, including neuroprotective effects. In this regard, the exact molecular mechanisms are not well understood. Parkinson's disease (PD) is the second most common age-related neurodegenerative disease. Emerging evidence supports the hypothesis that PD is the result of complex interactions between genetic abnormalities, environmental toxins, mitochondrial dysfunction, and other cellular processes, such as DNA methylation. In this context, BDNF (brain-derived neurotrophic factor) and GDNF (glial cell line-derived neurotrophic factor) have a pivotal role because they are both involved in neuron differentiation, survival, and synaptogenesis. In this study, we aimed to elucidate the potential role of two PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and their effects on BDNF and GDNF expression in the SH-SY5Y cell line. Cell viability was determined using the MTT assay, and flow cytometry analysis was used to verify the level of apoptosis. Transmission electron microscopy was performed to observe the cell ultrastructure and mitochondria morphology. BDNF and GDNF protein levels and mRNA were assayed by Western blotting and RT-PCR, respectively. Finally, methylated and hydroxymethylated DNA immunoprecipitation were performed in the BDNF and GDNF promoter regions. EPA, but not DHA, is able (i) to reduce the neurotoxic effect of neurotoxin 6-hydroxydopamine (6-OHDA) in vitro, (ii) to re-establish mitochondrial function, and (iii) to increase BNDF and GDNF expression via epigenetic mechanisms.

Novel Algorithm of Network Calcium Dynamics Analysis for Studying the Role of Astrocytes in Neuronal Activity in Alzheimer's Disease Models

Accumulated experimental data strongly suggest that astrocytes play an important role in the pathogenesis of neurodegeneration, including Alzheimer's disease (AD). The effect of astrocytes on the calcium activity of neuron-astroglia networks in AD modelling was the object of the present study. We have expanded and improved our approach's capabilities to analyze calcium activity. We have developed a novel algorithm to construct dynamic directed graphs of both astrocytic and neuronal networks. The proposed algorithm allows us not only to identify functional relationships between cells and determine the presence of network activity, but also to characterize the spread of the calcium signal from cell to cell. Our study showed that Alzheimer's astrocytes can change the functional pattern of the calcium activity of healthy nerve cells. When healthy nerve cells were cocultivated with astrocytes treated with Aβ42, activation of calcium signaling was found. When healthy nerve cells were cocultivated with 5xFAD astrocytes, inhibition of calcium signaling was observed. In this regard, it seems relevant to further study astrocytic-neuronal interactions as an important factor in the regulation of the functional activity of brain cells during neurodegenerative processes. The approach to the analysis of streaming imaging data developed by the authors is a promising tool for studying the collective calcium dynamics of nerve cells.

New Insights into lncRNAs in Aβ Cascade Hypothesis of Alzheimer's Disease

Alzheimer's disease (AD) is the most common type of dementia, but its pathogenesis is not fully understood, and effective drugs to treat or reverse the progression of the disease are lacking. Long noncoding RNAs (lncRNAs) are abnormally expressed and deregulated in AD and are closely related to the occurrence and development of AD. In addition, the high tissue specificity and spatiotemporal specificity make lncRNAs particularly attractive as diagnostic biomarkers and specific therapeutic targets. Therefore, an in-depth understanding of the regulatory mechanisms of lncRNAs in AD is essential for developing new treatment strategies. In this review, we discuss the unique regulatory functions of lncRNAs in AD, ranging from Aβ production to clearance, with a focus on their interaction with critical molecules. Additionally, we highlight the advantages and challenges of using lncRNAs as biomarkers for diagnosis or therapeutic targets in AD and present future perspectives in clinical practice.

From kitchen to clinic: Pharmacotherapeutic potential of common spices in Indian cooking in age-related neurological disorders

Aging is described as an advanced time-related collection of changes that may negatively affect with the risk of several diseases or death. Aging is a main factor of several age-related neurological disorders, including neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease, and dementia), stroke, neuroinflammation, neurotoxicity, brain tumors, oxidative stress, and reactive oxygen species (ROS). Currently available medications for age-related neurological disorders may lead to several side effects, such as headache, diarrhea, nausea, gastrointestinal (GI) diseases, dyskinesia, and hallucinosis. These days, studies on plant efficacy in traditional medicine are being conducted because herbal medicine is affordable, safe, and culturally acceptable and easily accessible. The Indian traditional medicine system called Ayurveda uses several herbs and medicinal plants to treat various disorders including neurological disorders. This review aims to summarize the data on the neuroprotective potential of the following common Indian spices widely used in Ayurveda: cumin (Cuminum cyminum (L.), Apiaceae), black cumin (Nigella sativa (L.), Ranunculaceae), black pepper (Piper nigrum (L.), Piperaceae), curry leaf tree (Murraya koenigii (L.), Spreng Rutaceae), fenugreek (Trigonella foenum-graecum (L.), Fabaceae), fennel (Foeniculum vulgare Mill, Apiaceae), cardamom (Elettaria cardamomum (L.) Maton, Zingiberaceae), cloves (Syzygium aromaticum (L.) Merr. & L.M.Perry, Myrtaceae), and coriander (Coriandrum sativum (L.), Apiaceae) in age-related neurological disorders.

Neurotrophic factors in the porcine ovary: Their effects on follicular growth, oocyte maturation, and developmental competence

Pigs are cost-effective industrial animals because they produce a large number of offspring and have shorter rebreeding intervals compared with other animals, such as non-human primates. The reproductive physiology of pigs has been studied over the past several decades. However, there is not enough research on the effects of the neurotrophic factors on the ovarian physiology and development in pigs. As the ovary is a highly innervated organ, various neurotrophic factors during ovarian development can promote the growth of nerve fibers and improve the development of ovarian cells. Thus, investigating the role of neurotrophic factors on ovarian development, and the relationship between neurotrophic factors and porcine female reproduction is worth studying. In this review, we focused on the physiological roles of various neurotrophic factors in porcine ovaries and summarized the current status of the studies related to the relationship between neurotrophic factors and porcine ovarian development.

Molecular Mechanisms of Exercise in Brain Disorders: a Focus on the Function of Brain-Derived Neurotrophic Factor-a Narrative Review

The natural aging process as well as many age-related diseases is associated with impaired metabolic adaptation and declined ability to cope with stress. As major causes of disability and morbidity during the aging process, brain disorders, including psychiatric and neurodegenerative disorders, are likely to increase across the globe in the future decades. This narrative review investigates the link among exercise and brain disorders, aging, and inflammatory biomarkers, along with the function of brain-derived neurotrophic factor. For this study, related manuscript from all databases, Google scholar, Scopus, PubMed, and ISI were assessed. Also, in the search process, the keywords of exercise, neurodegeneration, neurotrophin, mitochondrial dysfunction, and aging were used. Mitochondrial abnormality increases neuronal abnormality and brain disease during the aging process. Stress and inflammatory factors caused by lifestyle and aging also increase brain disorders. Evidences suggest that exercise, as a noninvasive treatment strategy, has antioxidant effects and can reduce neuronal lesions. Brain-derived neurotrophic factor expression following the exercise can reduce brain symptoms; however, careful consideration should be given to a number of factors affecting the results.

Effects of the combination of high-intensity interval training and Ecdysterone on learning and memory abilities, antioxidant enzyme activities, and neuronal population in an Amyloid-beta-induced rat model of Alzheimer's disease

AIMS

Oxidative stress and neuronal death are the primary reasons for the progression of amyloid-beta (Aβ) deposition and cognitive deficits in Alzheimer's disease (AD). Ecdysterone (ecdy), a common derivative of ecdysteroids, possesses free radical scavenging and cognitive-improving effects. High-intensity interval training (HIIT) can be a therapeutic strategy for improving cognitive decline and oxidative stress. The present study was aimed to evaluate the effect of HIIT exercise and ecdy consumption synergistically on the changes in learning and memory functions, activities of hippocampal antioxidant enzymes, and neuronal population after AD induced by Aβ in male rats.

MATERIALS AND METHODS

Following ten days of Aβ injection, HIIT exercise and ecdy treatment (10 mg/kg/day; P.O.) were initiated and continued for eight consecutive weeks in rats. At the end of the treatment period, the rat's learning and memory functions were assessed using Morris water maze and passive avoidance tests. The activity of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GRx), and changes in neuronal population were evaluated in rats' brains.

RESULTS

The results indicated that Aβ injection disrupted spatial/passive avoidance learning and memory in both tests, accompanied by a decrease in the SOD and CAT (as endogenous antioxidants) in rats' hippocampus. Additionally, Aβ injection resulted in neuronal loss in the cerebral cortex and hippocampus. Although the consumption of ecdy separately improved spatial/passive avoidance learning and memory impairments, recovered hippocampal activity of SOD, CAT, GRx, and prevented the hippocampal neuronal loss, its combination along with HIIT resulted in a more powerful and effective amelioration in all the above-mentioned Aβ-neuropathological changes.

CONCLUSION

Our results confirm that a combination of HIIT and ecdy treatment could be a promising potential therapeutic option against AD-associated cognitive decline, owing to their free radical scavenging and neuroprotective properties.

Therapeutic Effects of High-Intensity Interval Training Exercise Alone and Its Combination with Ecdysterone Against Amyloid Beta-Induced Rat Model of Alzheimer's Disease: A Behavioral, Biochemical, and Histological Study

Hippocampal oxidative stress has a vital role in the pathophysiology of Alzheimer's disease (AD)-associated behavioral deficits. Ecdysterone (Ecdy), a natural product and primary steroid hormone, exhibits anti-oxidative and neuroprotective effects. High-intensity interval training (HIIT) has emerged as an effective method for improving physiological brain functions. The present study was designed to investigate the comparative effects of separate and combined HIIT and Ecdy treatment on behavioral functions, hippocampal oxidative status, histological changes in an amyloid-beta (Aβ)-induced rat model of AD. Adult male rats were treated simultaneously with HIIT exercise and Ecdy (10 mg/kg/day; P.O.), starting ten days after Aβ-injection, and they continued for eight consecutive weeks. At the end of the treatment course, the behavioral functions of the rats were assessed by commonly-used behavioral paradigms. Subsequently, brain samples were collected for histological analysis and hippocampus samples were collected for biochemical analysis. Results illustrated that Aβ injection impaired learning and memory performances in both novel object recognition and Barnes maze tests, reduced exploratory/locomotor activities in open field test, enhanced anxiety-like behavior in elevated plus-maze (P < 0.05). These behavioral deficits accompanied hippocampal oxidative stress (decreased total antioxidant capacity content and glutathione peroxidase enzyme activity, increased total oxidant status and malondialdehyde level) and neuronal loss in the cerebral cortex and hippocampus in H&E staining (P < 0.05). HIIT and Ecdy improved anxiety-like behavior, attenuated total oxidant status and malondialdehyde, and prevented the neuronal loss (P < 0.05). However, their combination resulted in a more complete and powerful improvement in all the above-mentioned Aβ-related deficits (P < 0.05). Overall, these data provide evidence that a combination of HIIT and Ecdy treatment improves Aβ-induced behavioral deficits, possibly through ameliorating hippocampal oxidative status and preventing neuronal loss.

Neuroprotective Effects of the DPP4 Inhibitor Vildagliptin in In Vivo and In Vitro Models of Parkinson's Disease

Parkinson’s disease (PD) is characterized by loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the midbrain. Restoration of nigrostriatal dopamine neurons has been proposed as a potential therapeutic strategy for PD. Because currently used PD therapeutics only help relieve motor symptoms and do not treat the cause of the disease, highly effective drugs are needed. Vildagliptin, a dipeptidyl peptidase 4 (DPP4) inhibitor, is an anti-diabetic drug with various pharmacological properties including neuroprotective effects. However, the detailed effects of vildagliptin against PD are not fully understood. We investigated the effects of vildagliptin on PD and its underlying molecular mechanisms using a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model and a 1-methyl-4-phenylpyridium (MPP⁺)-induced cytotoxicity model. Vildagliptin (50 mg/kg) administration significantly attenuated MPTP-induced motor deficits as evidenced by rotarod, pole, and nest building tests. Immunohistochemistry and Western blot analysis revealed that vildagliptin increased tyrosine hydroxylase-positive cells in the SNpc and striatum, which was reduced by MPTP treatment. Furthermore, vildagliptin activated MPTP-decreased PI3k/Akt and mitigated MPTP-increased ERK and JNK signaling pathways in the striatum. Consistent with signaling transduction in the mouse striatum, vildagliptin reversed MPP⁺-induced dephosphorylation of PI3K/Akt and phosphorylation of ERK and JNK in SH-SY5Y cells. Moreover, vildagliptin attenuated MPP⁺-induced conversion of LC3B-II in SH-SY5Y cells, suggesting its role in autophagy inhibition. Taken together, these findings indicate that vildagliptin has protective effects against MPTP-induced motor dysfunction by inhibiting dopaminergic neuronal apoptosis, which is associated with regulation of PI3k/Akt, ERK, and JNK signaling transduction. Our findings suggest vildagliptin as a promising repurposing drug to treat PD.

Therapeutic potential of glial cell line-derived neurotrophic factor and cell reprogramming for hippocampal-related neurological disorders

Hippocampus serves as a pivotal role in cognitive and emotional processes, as well as in the regulation of the hypothalamus-pituitary axis. It is known to undergo mild neurodegenerative changes during normal aging and severe atrophy in Alzheimer’s disease. Furthermore, dysregulation in the hippocampal function leads to epilepsy and mood disorders. In the first section, we summarized the most salient knowledge on the role of glial cell-line-derived neurotrophic factor and its receptors focused on aging, cognition and neurodegenerative and hippocampal-related neurological diseases mentioned above. In the second section, we reviewed the therapeutic approaches, particularly gene therapy, using glial cell-line-derived neurotrophic factor or its gene, as a key molecule in the development of neurological disorders. In the third section, we pointed at the potential of regenerative medicine, as an emerging and less explored strategy for the treatment of hippocampal disorders. We briefly reviewed the use of partial reprogramming to restore brain functions, non-neuronal cell reprogramming to generate neural stem cells, and neural progenitor cells as source-specific neuronal types to be implanted in animal models of specific neurodegenerative disorders.

Do Naturally Occurring Antioxidants Protect Against Neurodegeneration of the Dopaminergic System? A Systematic Revision in Animal Models of Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease and is characterized by a significant decrease in dopamine levels, caused by progressive degeneration of the dopaminergic neurons in the nigrostriatal pathway. Multiple mechanisms have been implicated in its pathogenesis, including oxidative stress, neuroinflammation, protein aggregation, mitochondrial dysfunction, insufficient support for neurotrophic factors and cell apoptosis. The absence of treatments capable of slowing or stopping the progression of PD has increased the interest in the natural antioxidant substances present in the diet, since they have multiple beneficial properties and it is possible that they can influence the mechanisms responsible for the dysfunction and death of dopaminergic neurons. Thus, the purpose of this systematic review is to analyze the results obtained in a set of studies carried out in the last years, which describe the neuroprotective, antioxidant and regenerative functions of some naturally occurring antioxidants in experimental models of PD. The results show that the exogenous no enzymatic antioxidants can significantly modify the biochemical and behavioral mechanisms that contribute to the pathophysiology of Parkinsonism in experimental animals. Therefore, it is possible that they may contribute to effective neuroprotection by providing a significant improvement in neuropathological markers. In conclusion, the results of this review suggest that exogenous antioxidants can be promising therapeutic candidates for the prevention and treatment of PD.

The Potential Role of Cytokines and Growth Factors in the Pathogenesis of Alzheimer's Disease

Alzheimer's disease (AD) is one of the most prominent neurodegenerative diseases, which impairs cognitive function in afflicted individuals. AD results in gradual decay of neuronal function as a consequence of diverse degenerating events. Several neuroimmune players (such as cytokines and growth factors that are key players in maintaining CNS homeostasis) turn aberrant during crosstalk between the innate and adaptive immunities. This aberrance underlies neuroinflammation and drives neuronal cells toward apoptotic decline. Neuroinflammation involves microglial activation and has been shown to exacerbate AD. This review attempted to elucidate the role of cytokines, growth factors, and associated mechanisms implicated in the course of AD, especially with neuroinflammation. We also evaluated the propensities and specific mechanism(s) of cytokines and growth factors impacting neuron upon apoptotic decline and further shed light on the availability and accessibility of cytokines across the blood-brain barrier and choroid plexus in AD pathophysiology. The pathogenic and the protective roles of macrophage migration and inhibitory factors, neurotrophic factors, hematopoietic-related growth factors, TAU phosphorylation, advanced glycation end products, complement system, and glial cells in AD and neuropsychiatric pathology were also discussed. Taken together, the emerging roles of these factors in AD pathology emphasize the importance of building novel strategies for an effective therapeutic/neuropsychiatric management of AD in clinics.

Knockdown of astrocytic Grin2a aggravates β-amyloid-induced memory and cognitive deficits through regulating nerve growth factor

Synapse degeneration correlates strongly with cognitive impairments in Alzheimer's disease (AD) patients. Soluble Amyloid-beta (Aβ) oligomers are thought as the major trigger of synaptic malfunctions. Our earlier studies have demonstrated that Aβ oligomers interfere with synaptic function through N-methyl-D-aspartate receptors (NMDARs). Our recent in vitro study found the neuroprotective role of astrocytic GluN2A in the promotion of synapse survival and identified nerve growth factor (NGF) derived from astrocytes, as a likely mediator of astrocytic GluN2A buffering against Aβ synaptotoxicity. Our present in vivo study focused on exploring the precise mechanism of astrocytic GluN2A influencing Aβ synaptotoxicity through regulating NGF. We generated an adeno-associated virus (AAV) expressing an astrocytic promoter (GfaABC1D) shRNA targeted to Grin2a (the gene encoding GluN2A) to perform astrocyte-specific Grin2a knockdown in the hippocampal dentate gyrus, after 3 weeks of virus vector expression, Aβ were bilaterally injected into the intracerebral ventricle. Our results showed that astrocyte-specific knockdown of Grin2a and Aβ application both significantly impaired spatial memory and cognition, which associated with the reduced synaptic proteins PSD95, synaptophysin and compensatory increased NGF. The reduced astrocytic GluN2A can counteract Aβ-induced compensatory protective increase of NGF through regulating pNF-κB, Furin and VAMP3, which modulating the synthesis, mature and secretion of NGF respectively. Our present data reveal, for the first time, a novel mechanism of astrocytic GluN2A in exerting protective effects on synapses at the early stage of Aβ exposure, which may contribute to establish new targets for AD prevention and early therapy.

The Biology and Pathobiology of Glutamatergic, Cholinergic, and Dopaminergic Signaling in the Aging Brain

The elderly population is growing worldwide, with important health and socioeconomic implications. Clinical and experimental studies on aging have uncovered numerous changes in the brain, such as decreased neurogenesis, increased synaptic defects, greater metabolic stress, and enhanced inflammation. These changes are associated with cognitive decline and neurobehavioral deficits. Although aging is not a disease, it is a significant risk factor for functional worsening, affective impairment, disease exaggeration, dementia, and general disease susceptibility. Conversely, life events related to mental stress and trauma can also lead to accelerated age-associated disorders and dementia. Here, we review human studies and studies on mice and rats, such as those modeling human neurodegenerative diseases, that have helped elucidate (1) the dynamics and mechanisms underlying the biological and pathological aging of the main projecting systems in the brain (glutamatergic, cholinergic, and dopaminergic) and (2) the effect of defective glutamatergic, cholinergic, and dopaminergic projection on disabilities associated with aging and neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. Detailed knowledge of the mechanisms of age-related diseases can be an important element in the development of effective ways of treatment. In this context, we briefly analyze which adverse changes associated with neurodegenerative diseases in the cholinergic, glutaminergic and dopaminergic systems could be targeted by therapeutic strategies developed as a result of our better understanding of these damaging mechanisms.

Adverse Maternal Environment Alters MicroRNA-10b-5p Expression and Its Epigenetic Profile Concurrently with Impaired Hippocampal Neurogenesis in Male Mouse Hippocampus

An adverse maternal environment (AME) predisposes adult offspring toward cognitive impairment in humans and mice. However, the underlying mechanisms remain poorly understood. Epigenetic changes in response to environmental exposure may be critical drivers of this change. Epigenetic regulators, including microRNAs, have been shown to affect cognitive function by altering hippocampal neurogenesis which is regulated in part by brain-derived neurotropic factor (BDNF). We sought to investigate the effects of AME on miR profile and their epigenetic characteristics, as well as neurogenesis and BDNF expression in mouse hippocampus. Using our mouse model of AME which is composed of maternal Western diet and prenatal environmental stress, we found that AME significantly increased hippocampal miR-10b-5p levels. We also found that AME significantly decreased DNA methylation and increased accumulations of active histone marks H3 lysine (K) 4me3, H3K14ac, and -H3K36me3 at miR-10b promoter. Furthermore, AME significantly decreased hippocampal neurogenesis by decreasing cell numbers of Ki67+ (proliferation marker), NeuroD1+ (neuronal differentiation marker), and NeuN+ (mature neuronal marker) in the dentate gyrus (DG) region concurrently with decreased hippocampal BDNF protein levels. We speculate that the changes in epigenetic profile at miR-10b promoter may contribute to upregulation of miR-10b-5p and subsequently lead to decreased BDNF levels in a model of impaired offspring hippocampal neurogenesis and cognition in mice.

Application of neurotrophic factor-secreting cells (astrocyte - Like cells) in the in-vitro Alzheimer's disease-like pathology on the human neuroblastoma cells

This study investigated physical proximity and paracrine activity of neurotrophic factor-secreting cells (NTF-SCs) on beta-amyloid treated cells. Mesenchymal stem cells (MSCs) - to-NTF-SCs (Astrocyte -like cells) trans-differentiation was confirmed using immunofluorescence staining of GFAP. BDNF and NGF levels were measured by ELISA. To mimic AD-like condition, SH-SY5Y cells were exposed to 10 μM Aβ1-42. SH-SY5Y cells were allocated into Control; and Aβ1-42-treated cells. Treated cells were further classified into three subgroups including Aβ1-42 cells, Aβ1-42 cells + NTF-SCs (CM) and Aβ1-42 cells + NTF-SCs co-culture. Cell viability was measured by MTT assay. Anti-inflammatory and anti-tau hyperphosphorylation effects of NTF-SCs were assessed via monitoring TNF-α and hyperphosphorylated Tau protein expression level respectively. To explore the impact of NTF-SCs on synaptogenesis and synaptic functionality, real-time PCR assay was performed to measure the expression of synapsine 1, homer 1 and ZIF268. The level of synaptophysin was monitored via immunofluorescence staining. Data showed MSCs potential in trans-differentiating toward NTF-SCs indicated with enhanced GFAP expression (p < 0.05). ELISA assay confirmed the superiority of NTF-SCs in releasing NGF and BDNF compared to the MSCs (p < 0.05). Aβ significantly induced SH-SY5Y cells death while juxtacrine and paracrine activity of NTF-SCs significantly blunted these conditions (p < 0.05). Trans-differentiated cells had potential to reduce Tau hyperphosphorylation and TNF-α level after treatment with Aβ through juxtacrine and paracrine mechanisms (p < 0.05). Moreover, NTF-SCs significantly increased the expression rate of synapsin 1, homer 1 and zif 268 genes in Aβ-treated cells compared to matched-control group coincided with induction of synaptophysin at the protein level(p < 0.05). NTF-SCs reversed AD-like neuropathological alterations in SH-SY5Y cells via paracrine and juxtacrine mechanisms.

Chronic Treatment with 50 mg/kg Cannabidiol Improves Cognition and Moderately Reduces Aβ40 Levels in 12-Month-Old Male AβPPswe/PS1ΔE9 Transgenic Mice

Alzheimer's disease (AD) is characterized by progressive cognitive decline and pathologically by the accumulation of amyloid-β (Aβ) and tau hyperphosphorylation causing neurodegeneration and neuroinflammation. Current AD treatments do not stop or reverse the disease progression, highlighting the need for more effective therapeutics. The phytocannabinoid cannabidiol (CBD) has demonstrated antioxidant, anti-inflammatory, and neuroprotective properties. Furthermore, chronic CBD treatment (20 mg/kg) reverses social and object recognition memory deficits in the AβPPxPS1 transgenic mouse model with only limited effects on AD-relevant brain pathology. Importantly, studies have indicated that CBD works in a dose-dependent manner. Thus, this study determined the chronic effects of 50 mg/kg CBD in male AβPPxPS1 mice. 12-month-old mice were treated with 50 mg/kg CBD or vehicle via daily intraperitoneal injections for 3 weeks prior to behavioral testing. A variety of cognitive domains including object and social recognition, spatial and fear-associated memory were evaluated. Pathological brain analyses for AD-relevant markers were conducted using ELISA and western blot. Vehicle-treated male AβPPxPS1 mice demonstrated impaired social recognition memory and reversal spatial learning. These deficits were restored after CBD treatment. Chronic CBD tended to reduce insoluble Aβ40 levels in the hippocampus of AβPPxPS1 mice but had no effect on neuroinflammation, neurodegeneration, or PPARγ markers in the cortex. This study demonstrates that therapeutic-like effects of 50 mg/kg CBD on social recognition memory and spatial learning deficits in AβPPxPS1 mice are accompanied by moderate brain region-specific reductions in insoluble Aβ40 levels. The findings emphasize the clinical relevance of CBD treatment in AD; however, the underlying mechanisms involved require further investigation.

Antioxidant and Neuroprotective Activity of Extra Virgin Olive Oil Extracts Obtained from Quercetano Cultivar Trees Grown in Different Areas of the Tuscany Region (Italy)

Neurodegenerative diseases are driven by several mechanisms such as inflammation, abnormal protein aggregation, excitotoxicity, mitochondrial dysfunction and oxidative stress. So far, no therapeutic strategies are available for neurodegenerative diseases and in recent years the research is focusing on bioactive molecules present in food. In particular, extra-virgin olive oil (EVOO) phenols have been associated to neuroprotection. In this study, we investigated the potential antioxidant and neuroprotective activity of two different EVOO extracts obtained from Quercetano cultivar trees grown in two different areas (plain and hill) of the Tuscany region (Italy). The different geographical origin of the orchards influenced phenol composition. Plain extract presented a higher content of phenyl ethyl alcohols, cinnammic acids, oleacein, oleocanthal and flavones; meanwhile, hill extract was richer in lignans. Hill extract was more effective in protecting differentiated SH-SY5Y cells from peroxide stress thanks to a marked upregulation of the antioxidant enzymes heme oxygenase 1, NADPH quinone oxidoreductase 1, thioredoxin Reductase 1 and glutathione reductase. Proteomic analysis revealed that hill extract plays a role in the regulation of proteins involved in neuronal plasticity and activation of neurotrophic factors such as BDNF. In conclusion, these data demonstrate that EVOOs can have important neuroprotective activities, but these effects are strictly related to their specific phenol composition.

The mechanistic link between selective vulnerability of the locus coeruleus and neurodegeneration in Alzheimer's disease

Alzheimer's disease (AD) is neuropathologically characterized by the intracellular accumulation of hyperphosphorylated tau and the extracellular deposition of amyloid-β plaques, which affect certain brain regions in a progressive manner. The locus coeruleus (LC), a small nucleus in the pons of the brainstem, is widely recognized as one of the earliest sites of neurofibrillary tangle formation in AD. Patients with AD exhibit significant neuronal loss in the LC, resulting in a marked reduction of its size and function. The LC, which vastly innervates several regions of the brain, is the primary source of the neurotransmitter norepinephrine (NE) in the central nervous system. Considering that NE is a major modulator of behavior, contributing to neuroprotection and suppression of neuroinflammation, degeneration of the LC in AD and the ultimate dysregulation of the LC-NE system has detrimental effects in the brain. In this review, we detail the neuroanatomy and function of the LC, its essential role in neuroprotection, and how this is dysregulated in AD. We discuss AD-related neuropathologic changes in the LC and mechanisms by which LC neurons are selectively vulnerable to insult. Further, we elucidate the neurotoxic effects of LC de-innervation both locally and at projection sites, and how this augments disease pathology, progression and severity. We summarize how preservation of the LC-NE system could be used in the treatment of AD and other neurodegenerative diseases affected by LC degeneration.

Withaferin-A Treatment Alleviates TAR DNA-Binding Protein-43 Pathology and Improves Cognitive Function in a Mouse Model of FTLD

Withaferin-A, an active withanolide derived from the medicinal herbal plant Withania somnifera induces autophagy, reduces TDP-43 proteinopathy, and improves cognitive function in transgenic mice expressing mutant TDP-43 modelling FTLD. TDP-43 is a nuclear DNA/RNA-binding protein with cellular functions in RNA transcription and splicing. Abnormal cytoplasmic aggregates of TDP-43 occur in several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), and limbic-predominant age-related TDP-43 encephalopathy (LATE). To date, no effective treatment is available for TDP-43 proteinopathies. Here, we tested the effects of withaferin-A (WFA), an active withanolide extracted from the medicinal herbal plant Withania somnifera, in a transgenic mouse model of FTLD expressing a genomic fragment encoding mutant TDP-43G348C. WFA treatment ameliorated the cognitive performance of the TDP-43G348C mice, and it reduced NF-κB activity and neuroinflammation in the brain. WFA alleviated TDP-43 pathology while it boosted the levels of the autophagic marker LC3BII in the brain. These data suggest that WFA and perhaps other autophagy inducers should be considered as potential therapy for neurodegenerative diseases with TDP-43 pathology.

Topical delivery of nerve growth factor for treatment of ocular and brain disorders

Neurotrophins are a family of proteins that support neuronal proliferation, survival, and differentiation in the central and peripheral nervous systems, and are regulators of neuronal plasticity. Nerve growth factor is one of the best-described neurotrophins and has advanced to clinical trials for treatment of ocular and brain diseases due to its trophic and regenerative properties. Prior trials over the past few decades have produced conflicting results, which have principally been ascribed to adverse effects of systemic nerve growth factor administration, together with poor penetrance of the blood-brain barrier that impairs drug delivery. Contrastingly, recent studies have revealed that topical ocular and intranasal nerve growth factor administration are safe and effective, suggesting that topical nerve growth factor delivery is a potential alternative to both systemic and invasive intracerebral delivery. The therapeutic effects of local nerve growth factor delivery have been extensively investigated for different ophthalmic diseases, including neurotrophic keratitis, glaucoma, retinitis pigmentosa, and dry eye disease. Further, promising pharmacologic effects were reported in an optic glioma model, which indicated that topically administered nerve growth factor diffused far beyond where it was topically applied. These findings support the therapeutic potential of delivering topical nerve growth factor preparations intranasally for acquired and degenerative brain disorders. Preliminary clinical findings in both traumatic and non-traumatic acquired brain injuries are encouraging, especially in pediatric patients, and clinical trials are ongoing. The present review will focus on the therapeutic effects of both ocular and intranasal nerve growth factor delivery for diseases of the brain and eye.

Neurotrophic Factors in Glaucoma and Innovative Delivery Systems

Glaucoma is a neurodegenerative disease and a worldwide leading cause of irreversible vision loss. In the last decades, high efforts have been made to develop novel treatments effective in inducing protection and/or recovery of neural function in glaucoma, including neurotrophic factors (NTFs). These approaches have shown encouraging data in preclinical setting; however, the challenge of sustained, targeted delivery to the retina and optic nerve still prevents the clinical translation. In this paper, the authors review and discuss the most recent advances for the use of NTFs treatment in glaucoma, including intraocular delivery. Novel strategies in drug and gene delivery technology for NTFs are proving effective in promoting long-term retinal ganglion cells (RGCs) survival and related functional improvements. Results of experimental and clinical studies evaluating the efficacy and safety of biodegradable slow-release NTF-loaded microparticle devices, encapsulated NTF-secreting cells implants, mimetic ligands for NTF receptors, and viral and non-viral NTF gene vehicles are discussed. NTFs are able to prevent and even reverse apoptotic ganglion cell death. Nevertheless, neuroprotection in glaucoma remains an open issue due to the unmet need of sustained delivery to the posterior segment of the eye. The recent advances in intraocular delivery systems pave the way for possible future use of NTFs in clinical practice for the treatment of glaucoma.

Integrated System Pharmacology and In Silico Analysis Elucidating Neuropharmacological Actions of Withania somnifera in the Treatment of Alzheimer's Disease

BACKGROUND

Withania somnifera (WS), also referred to as Medhya Rasayana (nootropic or rejuvenating), has traditionally been prescribed for various neurological ailments, including dementia. Despite substantial evidence, pharmacological roles of WS, neither as nootropic nor as an antidementia agent, are well-understood at the cellular and molecular levels.

OBJECTIVES

We aimed at elucidating the pharmacological action mechanisms of WS root constituents against Alzheimer's Disease (AD) pathology.

METHODS

Various bioinformatics tools and resources, including DAVID, Cytoscape, NetworkAnalyst and KEGG pathway database were employed to analyze the interaction of WS root bioactive molecules with the protein targets of AD-associated cellular processes. We also used a molecular simulation approach to validate the interaction of compounds with selected protein targets.

RESULTS

Network analysis revealed that β-sitosterol, withaferin A, stigmasterol, withanolide A, and withanolide D are the major constituents of WS root that primarily target the cellular pathways such as PI3K/Akt signaling, neurotrophin signaling and toll-like receptor signaling and proteins such as Tropomyosin receptor Kinase B (TrkB), Glycogen Synthase Kinase-3β (GSK-3β), Toll-Like Receptor 2/4 (TLR2/4), and β-secretase (BACE-1). Also, the in silico analysis further validated the interaction patterns and binding affinity of the major WS compounds, particularly stigmasterol, withanolide A, withanolide D and β-sitosterol with TrkB, GSK-3β, TLR2/4, and BACE-1.

CONCLUSION

The present findings demonstrate that stigmasterol, withanolide A, withanolide D and β-sitosterol are the major metabolites that are responsible for the neuropharmacological action of WS root against AD-associated pathobiology, and TrkB, GSK-3β, TLR2/4, and BACE-1 could be the potential druggable targets.

Mild traumatic brain injury exacerbates Parkinson's disease induced hemeoxygenase-2 expression and brain pathology: Neuroprotective effects of co-administration of TiO2 nanowired mesenchymal stem cells and cerebrolysin

Mild traumatic brain injury (mTBI) is one of the leading predisposing factors in the development of Parkinson's disease (PD). Mild or moderate TBI induces rapid production of tau protein and alpha synuclein (ASNC) in the cerebrospinal fluid (CSF) and in several brain areas. Enhanced tau-phosphorylation and ASNC alters the molecular machinery of the brain leading to PD pathology. Recent evidences show upregulation of constitutive isoform of hemeoxygenase (HO-2) in PD patients that correlates well with the brain pathology. mTBI alone induces profound upregulation of HO-2 immunoreactivity. Thus, it would be interesting to explore whether mTBI exacerbates PD pathology in relation to tau, ASNC and HO-2 expression. In addition, whether neurotrophic factors and stem cells known to reduce brain pathology in TBI could induce neuroprotection in PD following mTBI. In this review role of mesenchymal stem cells (MSCs) and cerebrolysin (CBL), a well-balanced composition of several neurotrophic factors and active peptide fragments using nanowired delivery in PD following mTBI is discussed based on our own investigation. Our results show that mTBI induces concussion exacerbates PD pathology and nanowired delivery of MSCs and CBL induces superior neuroprotection. This could be due to reduction in tau, ASNC and HO-2 expression in PD following mTBI, not reported earlier. The functional significance of our findings in relation to clinical strategies is discussed.

Therapeutic Potential of Repeated Intravenous Transplantation of Human Adipose-Derived Stem Cells in Subchronic MPTP-Induced Parkinson's Disease Mouse Model

Parkinson’s disease (PD) is the second most common neurodegenerative disease, which is clinically and pathologically characterized by motor dysfunction and the loss of dopaminergic neurons in the substantia nigra, respectively. PD treatment with stem cells has long been studied by researchers; however, no adequate treatment strategy has been established. The results of studies so far have suggested that stem cell transplantation can be an effective treatment for PD. However, PD is a progressively deteriorating neurodegenerative disease that requires long-term treatment, and this has been insufficiently studied. Thus, we aimed to investigate the therapeutic potential of human adipose-derived stem cells (hASC) for repeated vein transplantation over long-term in an animal model of PD. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model mice, hASCs were administered on the tail vein six times at two-week intervals. After the last injection of hASCs, motor function significantly improved. The number of dopaminergic neurons present in the nigrostriatal pathway was recovered using hASC transplantation. Moreover, the administration of hASC restored altered dopamine transporter expression and increased neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF), in the striatum. Overall, this study suggests that repeated intravenous transplantation of hASC may exert therapeutic effects on PD by restoring BDNF and GDNF expressions, protecting dopaminergic neurons, and maintaining the nigrostriatal pathway.

DHF-BAHPC molecule exerts ameliorative antioxidant status and reduced cadmium-induced toxicity in zebrafish (Danio rerio) embryos

In this study, we report the antioxidant and antitoxic potential of chemically synthesized 4-oxo-2-phenyl-4H-chromene-7,8-diyl bis((1-amino-2-hydroxypropyl)carbamate) (DHF-BAHPC) compound using in vitro and in vivo assays. The DHF-BAHPC was synthesized by linking 7,8-Dihydroxyflavone (DHF) with two molecules of Fmoc-threonine and characterized by Ultraviolet-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FT-IR), ¹H NMR, ¹³C NMR and Mass spectrometry (MS). In vitro, antioxidant assay results revealed that DHF-BAHPC has a dose-dependent radical scavenging potential towards DPPH, ABTS, FRAP and H₂O₂ radicals with an IC₅₀ range of 15.45, 66.27, 25.71, 4.375 μg/mL, respectively. Furthermore DHF-BAHPC treatment significantly altered cadmium (Cd) intoxicated zebrafish embryos by rescuing the developmental changes associated with severe histological and reduced the level of defensive antioxidant activities (SOD, CAT, GPx and GST). The overall results of the present study represented that DHF-BAHPC may be used as a potential drug in redox-based therapeutics.

On the Right Track to Treat Movement Disorders: Promising Therapeutic Approaches for Parkinson's and Huntington's Disease

Movement disorders are neurological conditions in which patients manifest a diverse range of movement impairments. Distinct structures within the basal ganglia of the brain, an area involved in movement regulation, are differentially affected for every disease. Among the most studied movement disorder conditions are Parkinson's (PD) and Huntington's disease (HD), in which the deregulation of the movement circuitry due to the loss of specific neuronal populations in basal ganglia is the underlying cause of motor symptoms. These symptoms are due to the loss principally of dopaminergic neurons of the substantia nigra (SN) par compacta and the GABAergic neurons of the striatum in PD and HD, respectively. Although these diseases were described in the 19th century, no effective treatment can slow down, reverse, or stop disease progression. Available pharmacological therapies have been focused on preventing or alleviating motor symptoms to improve the quality of life of patients, but these drugs are not able to mitigate the progressive neurodegeneration. Currently, considerable therapeutic advances have been achieved seeking a more efficacious and durable therapeutic effect. Here, we will focus on the new advances of several therapeutic approaches for PD and HD, starting with the available pharmacological treatments to alleviate the motor symptoms in both diseases. Then, we describe therapeutic strategies that aim to restore specific neuronal populations or their activity. Among the discussed strategies, the use of Neurotrophic factors (NTFs) and genetic approaches to prevent the neuronal loss in these diseases will be described. We will highlight strategies that have been evaluated in both Parkinson's and Huntington's patients, and also the ones with strong preclinical evidence. These current therapeutic techniques represent the most promising tools for the safe treatment of both diseases, specifically those aimed to avoid neuronal loss during disease progression.

Nanomaterial integration into the scaffolding materials for nerve tissue engineering: a review

The nervous system, which consists of a complex network of millions of neurons, is one of the most highly intricate systems in the body. This complex network is responsible for the physiological and cognitive functions of the human body. Following injuries or degenerative diseases, damage to the nervous system is overwhelming because of its complexity and its limited regeneration capacity. However, neural tissue engineering currently has some capacities for repairing nerve deficits and promoting neural regeneration, with more developments in the future. Nevertheless, controlling the guidance of stem cell proliferation and differentiation is a challenging step towards this goal. Nanomaterials have the potential for the guidance of the stem cells towards the neural lineage which can overcome the pitfalls of the classical methods since they provide a unique microenvironment that facilitates cell-matrix and cell-cell interaction, and they can manipulate the cell signaling mechanisms to control stem cells' fate. In this article, the suitable cell sources and microenvironment cues for neuronal tissue engineering were examined. Afterward, the nanomaterials that impact stem cell proliferation and differentiation towards neuronal lineage were reviewed.