402 research outputs found
Potential antidepressant effects of scutellaria baicalensis, hericium erinaceus and rhodiola rosea
Recent studies focused on the pharmacology and feasibility of herbal compounds as a potential strategy to target a variety of human diseases ranging from metabolic to brain disorders. Accordingly, bioactive ingredients which are found within a variety of herbal compounds are reported to produce both neuroprotective and psychotropic activities which may help to combat mental disorders such as depression, anxiety, sleep disturbances and cognitive alterations. In the present manuscript, we focus on three herbs which appear effective in mitigating anxiety or depression with favourable risk-benefit profiles, namely Scutellaria baicalensis (S. baicalensis), Hericium erinaceus (H. erinaceus) and Rhodiola rosea (R. rosea). These three traditional folk medicinal herbs target the main biochemical events that are implicated in mental disorders, mimicking, to some extent, the mechanisms of action of conventional antidepressants and mood stabilizers with a wide margin of tolerability. In detail, they rescue alterations in neurotransmitter and neuro-endocrine systems, stimulate neurogenesis and the synthesis of neurotrophic factors, and they counteract oxidative stress, mitochondrial dysfunction and inflammation. Albeit the encouraging results that emerge from both experimental and clinical evidence, further studies are needed to confirm and better understand the mental-health promoting, and specifically, the antidepressant effects of these herbs
mTOR-related cell-clearing systems in epileptic seizures, an update
Recent evidence suggests that autophagy impairment is implicated in the epileptogenic mechanisms downstream of mTOR hyperactivation. This holds true for a variety of genetic and acquired epileptic syndromes besides malformations of cortical development which are classically known as mTORopathies. Autophagy suppression is sufficient to induce epilepsy in experimental models, while rescuing autophagy prevents epileptogenesis, improves behavioral alterations, and provides neuroprotection in seizure-induced neuronal damage. The implication of autophagy in epileptogenesis and maturation phenomena related to seizure activity is supported by evidence indicating that autophagy is involved in the molecular mechanisms which are implicated in epilepsy. In general, mTOR-dependent autophagy regulates the proliferation and migration of inter-/neuronal cortical progenitors, synapse development, vesicular release, synaptic plasticity, and importantly, synaptic clustering of GABAA receptors and subsequent excitatory/inhibitory balance in the brain. Similar to autophagy, the ubiquitinâproteasome system is regulated downstream of mTOR, and it is implicated in epileptogenesis. Thus, mTOR-dependent cell-clearing systems are now taking center stage in the field of epilepsy. In the present review, we discuss such evidence in a variety of seizure-related disorders and models. This is expected to provide a deeper insight into the molecular mechanisms underlying seizure activit
Favelas in the Media: Analysis of Territorial Stigmatization and Approaches for Change.
openIl Brasile costituisce un contesto straordinario per l'analisi delle intricate dinamiche di disuguaglianza e stigmatizzazione geografica, date la sua vastitaÌ territoriale, la ricchezza della sua diversitaÌ culturale e le complesse contraddizioni sociali presenti. In questa tesi verraÌ esaminato il modo in cui i media influenzano e amplificano la percezione delle favelas brasiliane, contribuendo ad una diffusa stigmatizzazione territoriale. Inoltre, parleremo di come l'empowerment, in particolare attraverso l'educazione digitale fornita da ONG e associazioni come "MareÌ Vive", puoÌ combattere gli stereotipi negativi e aiutare a costruire una "comunitaÌ generativa" (Martins e Pavia, 2022). Con una popolazione variegata e una notevole diversitaÌ culturale, il Brasile offre un quadro di vitalitaÌ e bellezza. Tuttavia, dietro questa immagine si nasconde una sfida importante: la disuguaglianza sociale, la quale rappresenta un ostacolo significativo alla crescita economica del paese e al benessere della sua popolazione. Le favelas, insediamenti informali che si trovano spesso alle periferie delle grandi cittaÌ, sono i simboli della disuguaglianza nel Brasile. In queste zone, in cui vivono milioni di brasiliani, spesso sono presenti condizioni di vita difficili, con un accesso limitato a servizi essenziali come l'istruzione, la sanitaÌ e l'occupazione. Spesso, i media distorcono e stereotipano la percezione pubblica di queste comunitaÌ, il che porta ad un processo di stigmatizzazione che ostacola il progresso sociale ed economico. L'obiettivo di questa tesi eÌ analizzare come i media, attraverso la loro rappresentazione delle favelas, possano contribuire a perpetuare stereotipi dannosi. Si esamineraÌ come il processo di stigmatizzazione territoriale influisca sulla percezione delle favelas e influenzi il modo in cui queste comunitaÌ sono trattate dalle istituzioni e dalla societaÌ in generale. Si analizzeraÌ in che misura i media contribuiscano a rafforzare questi pregiudizi, andando ad elencare e analizzare le varie teorie di influenza dei media nel corso degli anni. Tuttavia, questa tesi non si limita a esplorare il problema della stigmatizzazione territoriale. Si metteraÌ anche in luce l'importanza delle iniziative che cercano di contrastare questa tendenza dannosa. In particolare, verraÌ esaminato il ruolo fondamentale dell'empowerment comunitario nella creazione di una "comunitaÌ generativa" all'interno delle favelas. Tramite programmi di educazione digitale, forniti da ONG e associazioni come "MareÌ Vive," i giovani delle favelas possono acquisire competenze che cambiano la loro prospettiva sul futuro e sulle opportunitaÌ disponibili.Brazil provides an extraordinary context for the analysis of intricate dynamics of inequality and geographical stigmatization, given its vast territorial expanse, the richness of its cultural diversity, and the complex social contradictions it harbors. This thesis will examine how the media influence and amplify the perception of Brazilian favelas, contributing to a widespread territorial stigmatization. Furthermore, we will discuss how empowerment, particularly through digital education provided by NGOs and associations like "MareÌ Vive," can combat negative stereotypes and help build a "generative community" (Martins and Pavia, 2022). With a diverse population and significant cultural variety, Brazil offers a vibrant and beautiful landscape. However, behind this image lies a significant challenge: social inequality, which represents a substantial barrier to the country's economic growth and the well-being of its people. Favelas, informal settlements often located on the outskirts of major cities, symbolize inequality in Brazil. In these areas, where millions of Brazilians live, difficult living conditions are often present, with limited access to essential services such as education, healthcare, and employment. Frequently, the media distorts and stereotypes the public perception of these communities, leading to a process of stigmatization that hinders social and economic progress. The objective of this thesis is to analyze how the media, through their representation of favelas, can contribute to perpetuating harmful stereotypes. We will examine how the process of territorial stigmatization influences the perception of favelas and affects how these communities are treated by institutions and society at large. We will assess to what extent the media contributes to reinforcing these prejudices, listing and analyzing various media influence theories over the years. However, this thesis does not limit itself to exploring the issue of territorial stigmatization. It will also highlight the importance of initiatives that seek to counter this detrimental trend. In particular, we will examine the fundamental role of community empowerment in creating a "generative community" within the favelas. Through digital education programs provided by NGOs and associations like "MareÌ Vive," young people in favelas can acquire skills that change their perspective on the future and the available opportunities
The effects of proteasome on baseline and methamphetamine-dependent dopamine transmission.
Abstract The Ubiquitin Proteasome System (UPS) is a major multi-catalytic machinery, which guarantees cellular proteolysis and turnover. Beyond cytosolic and nuclear cell compartments, the UPS operates at the synapse to modulate neurotransmission and plasticity. In fact, dysregulations of the UPS are linked with early synaptic alterations occurring in a variety of dopamine (DA)-related brain disorders. This is the case of psychiatric conditions such as methamphetamine (METH) addiction. While being an extremely powerful DA releaser, METH impairs UPS activity, which is largely due to DA itself. In turn, pre- and post- synaptic neurons of the DA circuitry show a high vulnerability to UPS inhibition. Thus, alterations of DA transmission and UPS activity are intermingled within a chain of events underlying behavioral alterations produced by METH. These findings, which allow escaping the view of a mere implication of the UPS in protein toxicity-related mechanisms, indicate a more physiological role for the UPS in modulating DA-related behavior. This is seminal for those plasticity mechanisms which underlie overlapping psychiatric disorders such as METH addiction and schizophrenia
Autophagy as a gateway for the effects of methamphetamine: From neurotransmitter release and synaptic plasticity to psychiatric and neurodegenerative disorders.
As a major eukaryotic cell clearing machinery, autophagy grants cell proteostasis, which is key for neurotransmitter release, synaptic plasticity, and neuronal survival. In line with this, besides neuropathological events, autophagy dysfunctions are bound to synaptic alterations that occur in mental disorders, and early on, in neurodegenerative diseases. This is also the case of methamphetamine (METH) abuse, which leads to psychiatric disturbances and neurotoxicity. While consistently altering the autophagy machinery, METH produces behavioral and neurotoxic effects through molecular and biochemical events that can be recapitulated by autophagy blockade. These consist of altered physiological dopamine (DA) release, abnormal stimulation of DA and glutamate receptors, as well as oxidative, excitotoxic, and neuroinflammatory events. Recent molecular insights suggest that METH early impairs the autophagy machinery, though its functional significance remains to be investigated. Here we discuss evidence suggesting that alterations of DA transmission and autophagy are intermingled within a chain of events underlying behavioral alterations and neurodegenerative phenomena produced by METH. Understanding how METH alters the autophagy machinery is expected to provide novel insights into the neurobiology of METH addiction sharing some features with psychiatric disorders and parkinsonism
Cell-clearing systems bridging repeat expansion proteotoxicity and neuromuscular junction alterations in ALS and SBMA
The coordinated activities of autophagy and the ubiquitin proteasome system (UPS) are key to preventing the aggregation and toxicity of misfold-prone proteins which manifest in a number of neurodegenerative disorders. These include proteins which are encoded by genes containing nucleotide repeat expansions. In the present review we focus on the overlapping role of autophagy and the UPS in repeat expansion proteotoxicity associated with chromosome 9 open reading frame 72 (C9ORF72) and androgen receptor (AR) genes, which are implicated in two motor neuron disorders, amyotrophic lateral sclerosis (ALS) and spinal-bulbar muscular atrophy (SBMA), respectively. At baseline, both C9ORF72 and AR regulate autophagy, while their aberrantly-expanded isoforms may lead to a failure in both autophagy and the UPS, further promoting protein aggregation and toxicity within motor neurons and skeletal muscles. Besides proteotoxicity, autophagy and UPS alterations are also implicated in neuromuscular junction (NMJ) alterations, which occur early in both ALS and SBMA. In fact, autophagy and the UPS intermingle with endocytic/secretory pathways to regulate axonal homeostasis and neurotransmission by interacting with key proteins which operate at the NMJ, such as agrin, acetylcholine receptors (AChRs), and adrenergic beta2 receptors (B2-ARs). Thus, alterations of autophagy and the UPS configure as a common hallmark in both ALS and SBMA disease progression. The findings here discussed may contribute to disclosing overlapping molecular mechanisms which are associated with a failure in cell-clearing systems in ALS and SBMA
The multiâfaceted effect of curcumin in glioblastoma from rescuing cell clearance to autophagyâindependent effects
The present review focuses on the multiâfaceted effects of curcumin on the neurobiology glioblastoma multiforme (GBM), with a special emphasis on autophagy (ATG)âdependent molecular pathways activated by such a natural polyphenol. This is consistent with the effects of curcumin in a variety of experimental models of neurodegeneration, where the molecular events partially overlap with GBM. In fact, curcumin broadly affects various signaling pathways, which are similarly affected in cell degeneration and cell differentiation. The antitumoral effects of curcumin include growth inhibition, cell cycle arrest, antiâmigration and antiâinvasion, as well as chemoâ and radioâsensitizing activity. Remarkably, most of these effects rely on mammalian target of rapamycin (mTOR)âdependent ATG induction. In addition, curcumin targets undifferentiated and highly tumorigenic GBM cancer stem cells (GSCs). When rescuing ATG with curcumin, the tumorigenic feature of GSCs is suppressed, thus counteracting GBM establishment and growth. It is noteworthy that targeting GSCs may also help overcome therapeutic resistance and reduce tumor relapse, which may lead to a significant improvement of GBM prognosis. The present review focuses on the multiâfaceted effects of curcumin on GBM neurobiology, which represents an extension to its neuroprotective efficacy
Autophagy-Based Hypothesis on the Role of Brain Catecholamine Response During Stress
Stressful events, similar to abused drugs, significantly affect the homeostatic balance of the catecholamine brain systems while activating compensation mechanisms to restore balance. In detail, norepinephrine (NE)- and dopamine (DA)-containing neurons within the locus coeruleus (LC) and ventral tegmental area (VTA), are readily and similarly activated by psychostimulants and stressful events involving neural processes related to perception, reward, cognitive evaluation, appraisal, and stress-dependent hormonal factors. Brain catecholamine response to stress results in time-dependent regulatory processes involving mesocorticolimbic circuits and networks, where LC-NE neurons respond more readily than VTA-DA neurons. LC-NE projections are dominant in controlling the forebrain DA-targeted areas, such as the nucleus accumbens (NAc) and medial pre-frontal cortex (mPFC). Heavy and persistent coping demand could lead to sustained LC-NE and VTA-DA neuronal activity, that, when persisting chronically, is supposed to alter LC-VTA synaptic connections. Increasing evidence has been provided indicating a role of autophagy in modulating DA neurotransmission and synaptic plasticity. This alters behavior, and emotional/cognitive experience in response to drug abuse and occasionally, to psychological stress. Thus, relevant information to address the role of stress and autophagy can be drawn from psychostimulants research. In the present mini-review we discuss the role of autophagy in brain catecholamine response to stress and its dysregulation. The findings here discussed suggest a crucial role of regulated autophagy in the response and adaptation of LC-NE and VTA-DA systems to stress
Locus Coeruleus and neurovascular unit: From its role in physiology to its potential role in Alzheimerâs disease pathogenesis
Locus coeruleus (LC) is the main noradrenergic (NA) nucleus of the central nervous system. LC degenerates early during Alzheimer's disease (AD) and NA loss might concur to AD pathogenesis. Aside from neurons, LC terminals provide dense innervation of brain intraparenchymal arterioles/capillaries, and NA modulates astrocyte functions. The term neurovascular unit (NVU) defines the strict anatomical/functional interaction occurring between neurons, glial cells, and brain vessels. NVU plays a fundamental role in coupling the energy demand of activated brain regions with regional cerebral blood flow, it includes the bloodâbrain barrier (BBB), plays an active role in neuroinflammation, and participates also to the glymphatic system. NVU alteration is involved in AD pathophysiology through several mechanisms, mainly related to a relative oligoemia in activated brain regions and impairment of structural and functional BBB integrity, which contributes also to the intracerebral accumulation of insoluble amyloid. We review the existing data on the morphological features of LC-NA innervation of the NVU, as well as its contribution to neurovascular coupling and BBB proper functioning. After introducing the main experimental data linking LC with AD, which have repeatedly shown a key role of neuroinflammation and increased amyloid plaque formation, we discuss the potential mechanisms by which the loss of NVU modulation by LC might contribute to AD pathogenesis. Surprisingly, thus far not so many studies have tested directly these mechanisms in models of AD in which LC has been lesioned experimentally. Clarifying the interaction of LC with NVU in AD pathogenesis may disclose potential therapeutic targets for AD
The Role of Cellular Prion Protein in Promoting Stemness and Differentiation in Cancer
Cellular prion protein (PrPC) is seminal to modulate a variety of baseline cell functions to grant homeostasis. The classic role of such a protein was defined as a chaperone-like molecule being able to rescue cell survival. Nonetheless, PrPC also represents the precursor of the deleterious misfolded variant known as scrapie prion protein (PrPSc). This variant is detrimental in a variety of prion disorders. This multi-faceted role of PrP is greatly increased by recent findings showing how PrPC in its folded conformation may foster tumor progression by acting at multiple levels. The present review focuses on such a cancer-promoting effect. The manuscript analyzes recent findings on the occurrence of PrPC in various cancers and discusses the multiple effects, which sustain cancer progression. Within this frame, the effects of PrPC on stemness and differentiation are discussed. A special emphasis is provided on the spreading of PrPC and the epigenetic effects, which are induced in neighboring cells to activate cancer-related genes. These detrimental effects are further discussed in relation to the aberrancy of its physiological and beneficial role on cell homeostasis. A specific paragraph is dedicated to the role of PrPC beyond its effects in the biology of cancer to represent a potential biomarker in the follow up of patients following surgical resection
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