Extracellular vesicles in Alzheimer's disease.

Extracellular vesicles (EVs) are small vesicles released by cells that facilitate cell signaling. They are categorized based on their biogenesis and size. In the context of the central nervous system (CNS), EVs have been extensively studied for their role in both normal physiological functions and diseases like Alzheimer's disease (AD). AD is a neurodegenerative disorder characterized by cognitive decline and neuronal death. EVs have emerged as potential biomarkers for AD due to their involvement in disease progression. Specifically, EVs derived from neurons, astrocytes, and neuron precursor cells exhibit changes in quantity and composition in AD. Neuron-derived EVs have been found to contain key proteins associated with AD pathology, such as amyloid beta (Aß) and tau. Increased levels of Aß in neuron-derived EVs isolated from the plasma have been observed in individuals with AD and mild cognitive impairment, suggesting their potential as early biomarkers. However, the analysis of tau in neuron-derived EVs is still inconclusive. In addition to Aß and tau, neuron-derived EVs also carry other proteins linked to AD, including synaptic proteins. These findings indicate that EVs could serve as biomarkers for AD, particularly for early diagnosis and disease monitoring. However, further research is required to validate their use and explore potential therapeutic applications. To summarize, EVs are small vesicles involved in cell signaling within the CNS. They hold promise as biomarkers for AD, potentially enabling early diagnosis and monitoring of disease progression. Ongoing research aims to refine their use as biomarkers and uncover additional therapeutic applications.

As vesículas extracelulares (VEs) são pequenas estruturas liberadas pelas células que agem na sinalização celular. No sistema nervoso central (SNC), as VEs são estudadas em relação à doença de Alzheimer (DA), um distúrbio neurodegenerativo que cursa com declínio cognitivo e morte neuronal. As VEs podem ser biomarcadores potenciais para a DA devido ao seu papel na progressão da doença. As VEs derivadas de neurônios, astrócitos e células precursoras apresentam alterações na DA, contendo proteínas associadas à patologia da DA, como beta-amiloide (Aß) e tau. Níveis elevados de Aß foram observados nas VEs de neurônios de indivíduos com DA, sugerindo seu potencial como biomarcadores precoces. A análise de tau nas VEs de neurônios ainda é inconclusiva. Além disso, as VEs neurais carregam outras proteínas relacionadas à DA, incluindo proteínas sinápticas. As VEs podem ser promissoras como biomarcadores para o diagnóstico precoce e monitoramento da DA, porém mais pesquisas são necessárias para validar seu uso e explorar aplicações terapêuticas. Em resumo, as VEs são vesículas envolvidas na sinalização celular no SNC, com potencial como biomarcadores para a DA.

Is There a Connection between the Metabolism of Copper, Sulfur, and Molybdenum in Alzheimer's Disease? New Insights on Disease Etiology.

Alzheimer's disease (AD) and other forms of dementia was ranked 3rd in both the Americas and Europe in 2019 in a World Health Organization (WHO) publication listing the leading causes of death and disability worldwide. Copper (Cu) imbalance has been reported in AD and increasing evidence suggests metal imbalance, including molybdenum (Mo), as a potential link with AD occurrence.We conducted an extensive literature review of the last 60 years of research on AD and its relationship with Cu, sulfur (S), and Mo at out of range levels.Weanalyzed the interactions among metallic elements' metabolisms;Cu and Mo are biological antagonists, Mo is a sulfite oxidase and xanthine oxidase co-factor, and their low activities impair S metabolism and reduce uric acid, respectively. We found significant evidence in the literature of a new potential mechanism linking Cu imbalance to Mo and S abnormalities in AD etiology: under certain circumstances, the accumulation of Cu not bound to ceruloplasmin might affect the transport of Mo outside the blood vessels, causing a mild Mo deficiency that might lowerthe activity of Mo and S enzymes essential for neuronal activity. The current review provides an updated discussion of the plausible mechanisms combining Cu, S, and Mo alterations in AD.

Interaction of LRRK2 and α-Synuclein in Parkinson's Disease.

Parkinson's disease (PD) is a progressively debilitating neurodegenerative syndrome. It is best described as a movement disorder characterized by motor dysfunctions, progressive degeneration of dopaminergic neurons of the substantia nigra pars compacta, and abnormal intraneuronal protein aggregates, named Lewy bodies and Lewy neurites. Nevertheless, knowledge of the molecular events leading to this pathophysiology is incomplete. To date, only mutations in the α-synuclein and LRRK2-encoding genes have been associated with typical findings of clinical and pathologic PD. LRRK2 appears to have a central role in the pathogenesis of PD as it is associated with α-synuclein pathology and other proteins implicated in neurodegeneration. Thus, LRRK2 dysfunction may influence the accumulation of α-synuclein and its pathology through diverse pathomechanisms altering cellular functions and signaling pathways, including immune system, autophagy, vesicle trafficking, and retromer complex modulation. Consequently, development of novel LRRK2 inhibitors can be justified to treat the neurodegeneration associated with abnormal α-synuclein accumulation.

G2019S-LRRK2 Expression Augments α-Synuclein Sequestration into Inclusions in Neurons.

UNLABELLED: Pathologic inclusions define α-synucleinopathies that include Parkinson's disease (PD). The most common genetic cause of PD is the G2019S LRRK2 mutation that upregulates LRRK2 kinase activity. However, the interaction between α-synuclein, LRRK2, and the formation of α-synuclein inclusions remains unclear. Here, we show that G2019S-LRRK2 expression, in both cultured neurons and dopaminergic neurons in the rat substantia nigra pars compact, increases the recruitment of endogenous α-synuclein into inclusions in response to α-synuclein fibril exposure. This results from the expression of mutant G2019S-LRRK2, as overexpression of WT-LRRK2 not only does not increase formation of inclusions but reduces their abundance. In addition, treatment of primary mouse neurons with LRRK2 kinase inhibitors, PF-06447475 and MLi-2, blocks G2019S-LRRK2 effects, suggesting that the G2019S-LRRK2 potentiation of inclusion formation depends on its kinase activity. Overexpression of G2019S-LRRK2 slightly increases, whereas WT-LRRK2 decreases, total levels of α-synuclein. Knockdown of total α-synuclein with potent antisense oligonucleotides substantially reduces inclusion formation in G2019S-LRRK2-expressing neurons, suggesting that LRRK2 influences α-synuclein inclusion formation by altering α-synuclein levels. These findings support the hypothesis that G2019S-LRRK2 may increase the progression of pathological α-synuclein inclusions after the initial formation of α-synuclein pathology by increasing a pool of α-synuclein that is more susceptible to forming inclusions. SIGNIFICANCE STATEMENT: α-Synuclein inclusions are found in the brains of patients with many different neurodegenerative diseases. Point mutation, duplication, or triplication of the α-synuclein gene can all cause Parkinson's disease (PD). The G2019S mutation in LRRK2 is the most common known genetic cause of PD. The interaction between G2019S-LRRK2 and α-synuclein may uncover new mechanisms and targets for neuroprotection. Here, we show that expression of G2019S-LRRK2 increases α-synuclein mobility and enhances aggregation of α-synuclein in primary cultured neurons and in dopaminergic neurons of the substantia nigra pars compacta, a susceptible brain region in PD. Potent LRRK2 kinase inhibitors, which are being developed for clinical use, block the increased α-synuclein aggregation in G2019S-LRRK2-expressing neurons. These results demonstrate that α-synuclein inclusion formation in neurons can be blocked and that novel therapeutic compounds targeting this process by inhibiting LRRK2 kinase activity may slow progression of PD-associated pathology.

The G2019S LRRK2 mutation increases myeloid cell chemotactic responses and enhances LRRK2 binding to actin-regulatory proteins.

The Leucine rich repeat kinase 2 (LRRK2) gene is genetically and biochemically linked to several diseases that involve innate immunity. LRRK2 protein is highly expressed in phagocytic cells of the innate immune system, most notably in myeloid cells capable of mounting potent pro-inflammatory responses. Knockdown of LRRK2 protein in these cells reduces pro-inflammatory responses. However, the effect of LRRK2 pathogenic mutations that cause Parkinson's disease on myeloid cell function is not clear but could provide insight into LRRK2-linked disease. Here, we find that rats expressing G2019S LRRK2 have exaggerated pro-inflammatory responses and subsequent neurodegeneration after lipopolysaccharide injections in the substantia nigra, with a marked increase in the recruitment of CD68 myeloid cells to the site of injection. While G2019S LRRK2 expression did not affect immunological homeostasis, myeloid cells expressing G2019S LRRK2 show enhanced chemotaxis both in vitro in two-chamber assays and in vivo in response to thioglycollate injections in the peritoneum. The G2019S mutation enhanced the association between LRRK2 and actin-regulatory proteins that control chemotaxis. The interaction between G2019S LRRK2 and actin-regulatory proteins can be blocked by LRRK2 kinase inhibitors, although we did not find evidence that LRRK2 phosphorylated these interacting proteins. These results suggest that the primary mechanism of G2019S LRRK2 with respect to myeloid cell function in disease may be related to exaggerated chemotactic responses.

Leucine-rich repeat kinase 2 deficiency is protective in rhabdomyolysis-induced kidney injury.

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common known genetic cause of Parkinson's disease, and LRRK2 is also linked to Crohn's and Hansen's disease. LRRK2 is expressed in many organs in mammals but is particularly abundant in the kidney. We find that LRRK2 protein is predominantly localized to collecting duct cells in the rat kidney, with much lower expression in other kidney cells. While genetic knockout (KO) of LRRK2 expression is well-tolerated in mice and rats, a unique age-dependent pathology develops in the kidney. The cortex and medulla of LRRK2 KO rat kidneys become darkly pigmented in early adulthood, yet aged animals display no overt signs of kidney failure. Accompanying the dark pigment we find substantial macrophage infiltration in LRRK2 KO kidneys, suggesting the presence of chronic inflammation that may predispose to kidney disease. Unexpectedly, the dark kidneys of the LRRK2 KO rats are highly resistant to rhabdomyolysis-induced acute kidney injury compared with wild-type rats. Biochemical profiling of the LRRK2 KO kidneys using immunohistochemistry, proteomic and lipidomic analyses show a massive accumulation of hemoglobin and lipofuscin in renal tubules that account for the pigmentation. The proximal tubules demonstrate a corresponding up-regulation of the cytoprotective protein heme oxygenase-1 (HO-1) which is capable of mitigating acute kidney injury. The unusual kidney pathology of LRRK2 KO rats highlights several novel physiological roles for LRRK2 and provides indirect evidence for HO-1 expression as a protective mechanism in acute kidney injury in LRRK2 deficiency.

Utilização do diclofenaco na prática clínica: revisão das evidências terapêuticas e ações farmacológicas / Use of diclofenac in clinical practice: review of the therapeutic evidence and pharmacologic actions

JUSTIFICATIVA E OBJETIVOS: Os anti-inflamatórios não esteroides (AINES) apresentam atividade farmacológica de inibição das isoenzimas ciclo-oxigenase-1 (COX-1) e ciclo-oxigenase-2 (COX-2) em graus diversos, cujos perfis de segurança variam individualmente.A eficácia é semelhante, porém os possíveis eventos adversos são relevantes nas decisões do tratamento prescrito. O diclofenaco está disponível internacionalmente há mais de 40 anos, tendo seu perfil farmacológico e de segurança documentados em diversos estudos básicos e clínicos. O objetivo desta revisão da literatura foi de apresentar aspectos da dor e do uso de diclofenaco na prática clínica, incluindo as indicações as questões de segurança e a eficácia do medicamento. CONTEÚDO: Esta revisão da literatura apresentará a farmacologia básica do diclofenaco, bem como evidências terapêuticas com o uso deste fármaco em diversas condições dolorosas e suas implicações na prática clínica. CONCLUSÃO: O diclofenaco tem demonstrado eficácia clínica no tratamento de diversas condições dolorosas, entre estas lombalgias, artrites, dores pós-traumáticas e pós-cirúrgicas, dismenorreias,bem como cólica renal e biliar. Vale ressaltar que, na avaliação de um paciente apresentando dor e ao decidir um plano de tratamento e na prescrição de qualquer medicamento, cabe ao médico avaliar cuidadosamente o paciente para determinar o melhor curso de ação no individuo, levando-se em consideração o histórico médico do paciente, comorbidades e uso de medicamentos concomitantes, a fim de proporcionar a melhor alternativa terapêutica, com redução máxima da dor e inflamação e a restauração da funcionalidade de forma mais segura.

BACKGROUND AND OBJECTIVES: The nonsteroidal antiinflammatory-drugs (NSAIDs) exhibit pharmacological activity inhibiting the isoenzymes cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) in varying degrees, and their safety profiles vary individually. Their efficacy is similar, but the possible adverse effects are relevant in deciding treatment prescriptions. Diclofenac has been available internationally for over 40 years, and its pharmacological and safety profile has been documented in numerous preclinical and clinical studies. The objective of this literature review was to present aspects of pain and the use of diclofenac in clinical practice, including indications, safety issues, and efficacy of the drug. CONTENTS: This literature review will present the basic pharmacology of diclofenac, as well as evidence for the therapeutic use of this drug in several painful conditions and the implications for clinical practice. CONCLUSION: Diclofenac has shown clinical efficacy in the treatment of a variety of painful conditions, including lumbagos,arthritis, post-traumatic and post-surgical pain, dysmenorrhea,as well as renal and biliary colic. It is important to note that in the evaluation of a patient presenting pain and when deciding a treatment plan and the prescription of any medication, it is upto the physician to carefully assess the patient to determine the best course of action in that individual, taking into account thepatients' medical history, co-morbidities, and use of concomitant medications, in order to provide the best therapeutic alternative,with a maximum reduction of pain and inflammation and restoration of functionality in the safest possible way.

Aspectos fisiológicos do cálcio e sua disfunção em patologias neurodegenerativas / Physiological aspects of calcium and its dysfunction in neurodegenerative diseases

O íon cálcio funciona como um segundo mensageiro que regula um amplo espectro de processos celulares. A diminuição ou perda do controle dos mecanismos que regulam a concentração intracelular desse íon está associada, respectivamente, ao envelhecimento dos neurônios e a doenças neurodegenerativas. A gênese dessas modificações é desconhecida. Entretanto, estudos recentes apontam para uma provável correlação entre expressão gênica alterada, estresse do retículo endoplasmático e os processos patológicos associados à disfunção na concentração intracelular de cálcio. O esclarecimento dessas questões poderá trazer novos alvos terapêuticos capazes de frear ou reverter tais alterações, combatendo, dessa forma, tanto o envelhecimento neuronal quanto as doenças neurodegenerativas.

Calcium is a second messenger that regulates a lot of cellular functions. The following mechanisms regulate the intracellular concentrations of the ion: influx, release, extrusion and storage. Decrease or loss in control of these mechanisms is related to aging of neurons and neurodegenerative diseases, respectively. The genesis of these alterations is unknown. However, recent studies point to a correlation between calcium dysfunction and altered gene expression. There is also a correlation between endoplasmic reticulum stress and pathological processes. Further investigations may reveal new therapeutical targets that can block or revert these alterations.

Correlacionando icterícia, resultados de exames laboratoriais e diagnósticos de doenças / Correlating jaundice, laboratory test results and diagnosis of diseases

Para descobrir quais as doenças que mais comumente cursam com a icterícia em pacientes internados no Hospital Universitário Antônio Pedro (HUAP) e correlacioná-las com marcadores bioquímicos foram utilizados dados extraídos de prontuários de pacientes internados durante os anos de 2005 a 2007. 0s dados foram analisados usando métodos estatísticos como qui-quadrado e teste Z. Utilizamos a análise das dosagens de aspartato-aminotrans ferase (AST), alanina-aminotransferase (ALT), fosfatase alcalina (FA), gama-glutamiltransferase (gama-GT), bilirrubina (Bb) total e suas frações direta e indireta. Os sinais e sintomas mais comuns na amostra estudada foram: dor abdominal, vômitos e colúria, que estão presentes em cerca de 60% das queixas dos pacientes estudados. Na população entre nove e 85 anos de idade, a análise sugere que AST e ALT nos chamam atenção para uma possível lesão hepática associada aos casos de icterícia. Enquanto que FA e GGT são marcadores de colestase. A bilirrubina direta tem média mais elevada no grupo de pacientes entre nove e 85 anos e a bilirrubina indireta atinge níveis maiores no grupo com até dois meses de vida. As dosagens bioquímicas são armas muito importantes na pesquisa etiológica dos casos de icterícia.

To find out which diseases most commonly lead to jaundice in hospitalized patients in HUAP and correlate them with biochemical markers. We used data from medical records of patients hospitalized during the years 2005 to 2007. The data were analyzed using statistical methods to test and chi-square-Z. We used the analysis of the strengths of AST, ALI, FA, GGT, Bb and its fractions total direct and indirect. The most common signs and symptoms in the sample studied were abdominal pain, vomiting and choluria that are present in about 60% of complaints from patients. In the population between nine and 85 years of age, the analysis suggests that AST and ALT in calling attention to a possible liver damage linked to cases of jaundice. While FA and gamma-GT are markers of cholestasis. The direct bilirubin is highest average in the group of patients between nine and 85 years and indirect bilirubin levels higher in the group with up to two months of life. The biochemical doses are very important weapons in the etiological research of cases of jaundice.

Osteoarthritis: clinical evaluation of diclofenac combined with the B complex vitamins / Osteoartrite: avaliação clínica da ação do diclofenaco com as vitaminas do complexo B

A double-blind, placebo controlled evaluation was performed on parallel groups of patients presenting osteoarthritis of the knee, hip or hand. The study aimed to evaluate the use of a combination of sustained-release diclofenac and vitamins B1, B6 and B12 in the treatment of the signs and symptoms of osteoarthritis. After screening and informed consent, randomized subjects underwent a 7-day treatment period with twice-daily oral therapy. Osteoarthritis pain, mobility and satisfaction assessments by both the subjects and the investigating physician were performed at each of the three visits to the study center before, during and at the end of the treatment period, along with physical examinations, laboratory evaluations and monitoring of adverse events and concomitant medications. Results were compared between the active and placebo treated groups (Group A and Group B, respectively).The active treatment was found to be superior to placebo in all of the pain, mobility and satisfaction assessments. Patients treated with the active substance were more willing to continue treatment at the end of the study. No significant difference was observed between the treatment groups in the physical examinations and laboratory evaluations performed.Based on the results observed in this double-blind clinical evaluation, we conclude that the combination of sustained-release diclofenac and vitamins B1, B6 and B12 is both well-tolerated and superior to placebo in the treatment of the signs and symptoms of OA in the study population evaluated.

Neural compression-induced neuralgias: clinical evaluation of the effect of nucleotides associated with vitamin B12

The use of a combination of uridine triphosphate (UTP), cytidine monophosphate (CMP), and hydroxocobalamin was evaluated in a double-blind, randomized study in the treatment of neuralgia due to degenerative orthopedic alterations with neural compression. Following informed consent, 80 patients were randomized to a 30 day treatment period. The subjects received a thrice-daily oral treatment regimen of either the combination treatment (Group A: total daily dose of 9mg UTP, 15mg CMP, 6 mg hydroxocobalamin) or vitamin B12 alone (Group B: total daily dose of 6 mg hydroxocobalamin). Efficacy measures evaluated global patient condition from the perspective of the subject and the investigating physician pain ? measured by a visual-analog scale and functionality, using a patient-response questionnaire. The safety evaluation took into account physical evaluations and laboratory tests performed at each visit to the study center as well as the incidence and severity of adverse events. At the end of the 30-day treatment period, there were reductions in the pain scale scores in both groups, however there was a significantly larger reduction in the scores of the Group A patients. The Patient Global Evaluation scores improved in both groups but showed greater improvement in Group A, while the Physician Global Evaluation improved significantly only in Group A. A similar finding was observed in the scores of the Patient Functionality Questionnaire. Based on the findings of this clinical trial, we conclude that the combination of UTP, CMP, and vitamin B12 has a positive effect on pain and functionality improvement in the treatment of degenerative orthopedic alterations with neural compression, in the study population evaluated.

Aspectos fisiológicos do cálcio e sua disfunção em patologias neurodegenerativas / Physiologic aspects of calcium and your dysfunction in neurodegenerative pathologies

O íon cálcio funciona como um segundo mensageiro que regula um amplo espectro de processos celulares. A diminuição ou perda do controle dos mecanismos que regulam a concentração intracelular desse íon está associada, respectivamente, ao envelhecimento dos neurônios e a doenças neurodegenerativas. A gênese dessas modificações é desconhecida. Entretanto, estudos recentes apontam para uma provável correlação entre expressão gênica alterada, estresse do retículo endoplasmático e os processos patológicos associados à disfunção na concentração intracelular do cálcio. O esclarecimento dessas questões poderá trazer novos alvos terapêuticos capazes de frear ou reverter tais alterações, combatendo, dessa forma, tanto o envelhecimento neuronal quanto as doenças neurodegenerativas.

Calcium is a second messenger that regulates a lot of cellular functions. The following mechanisms regulate the intracellular concentrations of the ion: influx, release, extrusion and storage. Decrease or loss in control of these mechanisms is related to aging of neurons and neurodegenerative diseases, respectively. The genesis of these alterations is unknown. However, recent studies point to a correlation between calcium dysfunction and altered gene expression. There is also a correlation between endoplasmic reticulum stress and pathological processes. Further investigations may reveal new therapeutical targets that can block or revert these alterations.

Óxido nítrico: inibição das plaquetas e participação na formação do trombo / Nitric oxide: inhibition of platelets and participation in thrombus formation

Neste artigo faremos uma revisão bibliográfica de modo que entendamos como o óxido nítrico (NO) atua sobre as plaquetas, compreendendo assim mais um mecanismo antiplaquetário. Nos últimos 25 anos a função do NO na biologia evoluiu do seu reconhecimento como poluente ambiental para substância endógena envolvida em comunicação intracelular e intercelular e na transdução de sinais. O NO é uma molécula polivalente que exerce um papel na regulação da hemostasia, sendo responsável pela inibição das plaquetas em todos os seus níveis de atuação, desde adesão até agregação, impedindo, dessa forma, posterior formação de trombo. Inúmeras desordens clínicas têm sido reportadas em que a insuficiência da produção de NO endógeno e, portanto, a ausência de inibição de ação plaquetária, parece contribuir para os eventos trombóticos.

In this article we make a review above the way that nitric oxide (NO) influence platelets over the past 25 years. The role of NO in biology has evolved from being recognized as an environmental pollutant to an endogenously produced substance involved in intracellular and intercellular communication and signal transduction. NO is a multifunctional molecule that plays a role in the regulation of hemostasis. It is responsible for platelets inhibition in all levels of its action, from adhesion to aggregation, preventing in this manner, thrombus formation. Several clinical disorders have been reported in which endogenous NO production insufficiency and, as a consequence, the absence of platelets action inhibition, seems to contribute to thrombotic events.