Interactions between Cytokines and the Pathogenesis of Prion Diseases: Insights and Implications.

Transmissible Spongiform Encephalopathies (TSEs), including prion diseases such as Bovine Spongiform Encephalopathy (Mad Cow Disease) and variant Creutzfeldt-Jakob Disease, pose unique challenges to the scientific and medical communities due to their infectious nature, neurodegenerative effects, and the absence of a cure. Central to the progression of TSEs is the conversion of the normal cellular prion protein (PrPC) into its infectious scrapie form (PrPSc), leading to neurodegeneration through a complex interplay involving the immune system. This review elucidates the current understanding of the immune response in prion diseases, emphasizing the dual role of the immune system in both propagating and mitigating the disease through mechanisms such as glial activation, cytokine release, and blood-brain barrier dynamics. We highlight the differential cytokine profiles associated with various prion strains and stages of disease, pointing towards the potential for cytokines as biomarkers and therapeutic targets. Immunomodulatory strategies are discussed as promising avenues for mitigating neuroinflammation and delaying disease progression. This comprehensive examination of the immune response in TSEs not only advances our understanding of these enigmatic diseases but also sheds light on broader neuroinflammatory processes, offering hope for future therapeutic interventions.

Integrated transcriptomics uncovers an enhanced association between the prion protein gene expression and vesicle dynamics signatures in glioblastomas.

BACKGROUND: Glioblastoma (GBM) is an aggressive brain tumor that exhibits resistance to current treatment, making the identification of novel therapeutic targets essential. In this context, cellular prion protein (PrPC) stands out as a potential candidate for new therapies. Encoded by the PRNP gene, PrPC can present increased expression levels in GBM, impacting cell proliferation, growth, migration, invasion and stemness. Nevertheless, the exact molecular mechanisms through which PRNP/PrPC modulates key aspects of GBM biology remain elusive. METHODS: To elucidate the implications of PRNP/PrPC in the biology of this cancer, we analyzed publicly available RNA sequencing (RNA-seq) data of patient-derived GBMs from four independent studies. First, we ranked samples profiled by bulk RNA-seq as PRNPhigh and PRNPlow and compared their transcriptomic landscape. Then, we analyzed PRNP+ and PRNP- GBM cells profiled by single-cell RNA-seq to further understand the molecular context within which PRNP/PrPC might function in this tumor. We explored an additional proteomics dataset, applying similar comparative approaches, to corroborate our findings. RESULTS: Functional profiling revealed that vesicular dynamics signatures are strongly correlated with PRNP/PrPC levels in GBM. We found a panel of 73 genes, enriched in vesicle-related pathways, whose expression levels are increased in PRNPhigh/PRNP+ cells across all RNA-seq datasets. Vesicle-associated genes, ANXA1, RAB31, DSTN and SYPL1, were found to be upregulated in vitro in an in-house collection of patient-derived GBM. Moreover, proteome analysis of patient-derived samples reinforces the findings of enhanced vesicle biogenesis, processing and trafficking in PRNPhigh/PRNP+ GBM cells. CONCLUSIONS: Together, our findings shed light on a novel role for PrPC as a potential modulator of vesicle biology in GBM, which is pivotal for intercellular communication and cancer maintenance. We also introduce GBMdiscovery, a novel user-friendly tool that allows the investigation of specific genes in GBM biology.

Use of immunohistochemistry and prion protein gene genotyping for detection of Scrapie in sheep in the state of Santa Catarina, Brazil / Uso da imuno-histoquímica e genotipagem do gene da proteína priônica para detecção de Scrapie em ovinos no estado de Santa Catarina, Brasil

Scrapie is a contagious disease of sheep and goats caused by prions (PrPSc). This study described an outbreak of Scrapie in sheep in the state of Santa Catarina, Brazil. An 1-year and 3-month-old sheep developed clinical signs characterized by motor incoordination of the pelvic limbs, pruritus and alopecia for three days. The 38 sheep from the flock that were over 1 year of age underwent biopsies of the third eyelid and rectal mucosa, in addition to anti-PrPsc immunohistochemistry (IHC). Blood containing EDTA was collected for PRNP gene genotyping from these sheep. Of the 38, 16 (42.10%) had immunostaining againstPrPSc. IHC-positive animals were euthanized and necropsied, as well as lambs from positive mothers. Different organs of the 19 necropsied animals were collected in 10% buffered formalin for histopathological examination and anti-PrPSc IHC of the obex. The histopathology of the obex of the female with neurological signs presented discrete multifocal vacuolization of the cytoplasm of neurons and neuropil. The anti-PrPSc IHC showed that two out of the 19 obex samples had cytoplasmic immunostaining in neurons. The genotypes reported were ARQ/ARQ in 47.36%, ARR/ARQ in 36.84%, ARQ/VRQ in 10.52% and ARQ/VRR in 5.28%. The genotyping helps to identify susceptible animals and select animals more resistant to the development of Scrapie. The anti-PrPSc IHC from lymphoid biopsies, and genotyping demonstrated the high number of positive sheep classified in susceptible group.

Scrapie é uma doença contagiosa de ovinos e caprinos causada por príons (PrPSc). O objetivo desse estudo é descrever um surto de Scrapie em ovinos no estado de Santa Catarina, Brasil. Uma ovelha de 1 ano e 3 meses desenvolveu sinais clínicos caracterizados por incoordenação motora dos membros pélvicos, prurido e alopecia durante três dias. Os 38 ovinos do rebanho que tinham idade acima de 1 ano foram submetidos a biópsias de terceira pálpebra e mucosa retal, além de imuno-histoquímica (IHQ) anti-PrPsc. Coletou-se sangue contendo EDTA para genotipagem do gene prnp destes ovinos. Dos 38 ovinos, 16 (42,10%) apresentaram imunomarcação na avaliação IHQ anti-PrPsc. Os animais positivos na IHQ foram eutanasiados e necropsiados, bem como os cordeiros das mães positivas. Diferentes órgãos dos 19 animais necropsiados foram coletados em formalina tamponada a 10% para exame histopatológico e IHQ anti-PrPsc do óbex. Na histopatologia do óbex da fêmea com sinal neurológico havia vacuolização do citoplasma de neurônios e neurópilo multifocal discreta. Na IHQ anti-PrPsc das 19 amostras de óbex, dois apresentaram imunomarcação citoplasmática em neurônios. Os genótipos encontrados foram ARQ/ARQ em 47,36%, ARR/ARQ em 36,84%, ARQ/VRQ em 10,52% e ARQ/VRR em 5,28%. A genotipagem auxilia a identificar os animais susceptíveis e seleciona animais mais resistentes ao desenvolvimento do Scrapie. A IHQ anti-PrPsc de biópsias de tecidos linfoides e a genotipagem demonstram o elevado número de ovinos positivos classificados no grupo susceptível.

A voltammetric peptide biosensor for Cu2+ metal ion quantification in coffee seeds.

A prion-derived copper(II)-binding peptide was assembled onto a gold electrode for the building of a voltammetric biosensor for measuring the Cu2+ metal ion in biological samples. The chosen sequence was H-CVNITKQHTVTTTT-NH2, with an appended cysteine residue for binding to the gold surface as a self-assembled monolayer and a histidine residue as the anchorage point for copper(II) complexation. The biosensor showed a linear range of 10-7 to 10-6 M with an 8.0 × 10-8 M detection limit and a 1.0 × 10-7 M quantification limit, with good precision, trueness, and absence of matrix effect. The quantification of Cu2+ was performed in the presence of other transition metal ions, such as Zn2+, Cd2+, Fe2+, or Ni2+, which indicates the excellent selectivity of the biosensor. When the modified electrode was applied for measuring copper(II) in calcined coffee seeds, a difference in copper amount was observed between two Coffea arabica cultivars that were submitted to a treatment with a copper-based antifungal, showing the applicability of the biosensor in the agricultural field.

Doença de Creutzfeltd-Jakob esporádica sem demência: relato de caso / Sporadic Creutzfeldt-Jakob disease without dementia: a case report

Resumo A doença de Creutzfeldt-Jakob é uma condição rara causada por príons. Embora a forma mais notória da doença seja a infecciosa, a forma mais comum é a chamada esporádica, onde ocorre a transformação de proteínas citoplasmáticas das células gliais em príons. Caracteriza-se por uma demência rapidamente progressiva cujo diagnóstico pode ser feito com grande precisão por meio de sinais clínicos, alterações típicas na ressonância magnética de crânio e o exame Real-Time Quaking-Induced Conversion (Rt-QuIC) no líquido cefalorraquidiano. Relatamos um caso da doença sem distúrbios cognitivos, mas com outros sinais clínicos comuns como anormalidades comportamentais, ataxia, reações extrapiramidais e mioclonia; observamos ainda alterações típicas na ressonância magnética do crânio (alterações de sinal afetando áreas dos lobos parietal e temporal) e um Rt-QuIC fortemente positivo. Entendemos que o relato do caso possa servir de alerta para que outros profissionais de saúde possam reconhecer a doença, aumentando as possibilidades de um diagnóstico mais preciso em casos semelhantes.

Abstract Creutzfeldt-Jakob disease is a rare condition caused by prions. Although the infectious form of the disease is the most well-known, the most common form is the so-called sporadic type, where the transformation of cytoplasmic proteins from glial cells into prions occurs. The disease is characterized by rapidly progressive dementia whose diagnosis can be made with great accuracy based on clinical signs, typical changes on magnetic resonance imaging and real-time quaking-induced conversion (Rt-QuIC) testing in cerebrospinal fluid. We report a case of the disease without cognitive disorders in the initial phase, but with other common clinical signs including behavioral abnormalities, ataxia, extrapyramidal features, and myoclonus; typical changes on magnetic resonance imaging of the skull (signal alterations affecting parietal and temporal lobes areas) and strongly positive Rt-QuIC test. This case report can serve to alert other health professionals on recognizing the disease and contribute to a more accurate diagnosis in similar cases.

PrP meets alpha-synuclein: Molecular mechanisms and implications for disease.

The discovery of prions has challenged dogmas and has revolutionized our understanding of protein-misfolding diseases. The concept of self-propagation via protein conformational changes, originally discovered for the prion protein (PrP), also applies to other proteins that exhibit similar behavior, such as alpha-synuclein (aSyn), a central player in Parkinson's disease and in other synucleinopathies. aSyn pathology appears to spread from one cell to another during disease progression, and involves the misfolding and aggregation of aSyn. How the transfer of aSyn between cells occurs is still being studied, but one important hypothesis involves receptor-mediated transport. Interestingly, recent studies indicate that the cellular prion protein (PrPC ) may play a crucial role in this process. PrPC has been shown to act as a receptor/sensor for protein aggregates in different neurodegenerative disorders, including Alzheimer's disease and amyotrophic lateral sclerosis. Here, we provide a comprehensive overview of the current state of knowledge regarding the interaction between aSyn and PrPC and discuss its role in synucleinopathies. We examine the properties of PrP and aSyn, including their structure, function, and aggregation. Additionally, we discuss the current understanding of PrPC 's role as a receptor/sensor for aSyn aggregates and identify remaining unanswered questions in this area of research. Ultimately, we posit that exploring the interaction between aSyn and PrPC may offer potential treatment options for synucleinopathies.

Distribution of the misfolded isoform of the prion protein in peripheral tissues and spinal cord of Rocky Mountain elk (Cervus elaphus nelsoni) with naturally occurring chronic wasting disease.

Chronic wasting disease (CWD) is an infectious transmissible spongiform encephalopathy of cervids associated with the presence of a misfolded prion protein (PrPCWD). Progression of PrPCWD distribution has been described using immunohistochemistry and histologic changes in a single section of brain stem at the level of the obex resulting in scores from 0 (early) to 10 (terminal) in elk with naturally occurring CWD. Here we describe the spread and distribution of PrPCWD in peripheral tissues and spinal cord in 16 wild and 17 farmed Rocky Mountain elk (Cervus elaphus nelsoni) with naturally occurring CWD and correlate these findings with obex scores. Spinal cord and approximately 110 peripheral tissues were collected, processed, stained with hematoxylin and eosin, and immunolabeled with the anti-prion protein monoclonal antibody F99/97.6.1. The medial retropharyngeal and tracheobronchial lymph nodes were the first tissues to accumulate PrPCWD, followed by other lymphoid tissues, myenteric plexus, spinal cord, and finally tissues outside of the lymphatic and neural systems. However, the only significant histological lesion observed was mild spongiform encephalopathy in the dorsal column of the lower spinal cord in elk with an obex score of ≥9. Initial exposure to CWD prions may be through the respiratory system and spread appears to occur primarily via the autonomic nervous system. Therefore, we suggest using obex scores as a proxy for stage of disease progression and verifying with key peripheral tissues.

In Vitro Characterization of Protein:Nucleic Acid Liquid-Liquid Phase Separation by Microscopy Methods and Nanoparticle Tracking Analysis.

Uncontrolled assembly/disassembly of physiologically formed liquid condensates is linked to irreversible aggregation. Hence, the quest for understanding protein-misfolding disease mechanism might lie in the studies of protein:nucleic acid coacervation. Several proteins with intrinsically disordered regions as well as nucleic acids undergo phase separation in the cellular context, and this process is key to physiological signaling and is related to pathologies. Phase separation is reproducible in vitro by mixing the target recombinant protein with specific nucleic acids at various stoichiometric ratios and then examined by microscopy and nanotracking methods presented herein. We describe protocols to qualitatively assess hallmarks of protein-rich condensates, characterize their structure using intrinsic and extrinsic dyes, quantify them, and analyze their morphology over time. Analysis by nanoparticle tracking provides information on the concentration and diameter of high-order protein oligomers formed in the presence of nucleic acid. Using the model protein (globular domain of recombinant murine PrP) and DNA aptamers (high-affinity oligonucleotides with 25 nucleotides in length), we provide examples of a systematic screening of liquid-liquid phase separation in vitro.

Phase separation of the mammalian prion protein: Physiological and pathological perspectives.

Abnormal phase transitions have been implicated in the occurrence of proteinopathies. Disordered proteins with nucleic acidbinding ability drive the formation of reversible micron-sized condensates capable of controlling nucleic acid processing/transport. This mechanism, achieved via liquid-liquid phase separation (LLPS), underlies the formation of long-studied membraneless organelles (e.g., nucleolus) and various transient condensates formed by driver proteins. The prion protein (PrP) is not a classical nucleic acid-binding protein. However, it binds nucleic acids with high affinity, undergoes nucleocytoplasmic shuttling, contains a long intrinsically disordered region rich in glycines and evenly spaced aromatic residues, among other biochemical/biophysical properties of bona fide drivers of phase transitions. Because of this, our group and others have characterized LLPS of recombinant PrP. In vitro phase separation of PrP is modulated by nucleic acid aptamers, and depending on the aptamer conformation, the liquid droplets evolve to solid-like species. Herein, we discuss recent studies and previous evidence supporting PrP phase transitions. We focus on the central role of LLPS related to PrP physiology and pathology, with a special emphasis on the interaction of PrP with different ligands, such as proteins and nucleic acids, which can play a role in prion disease pathogenesis. Finally, we comment on therapeutic strategies directed at the non-functional phase separation that could potentially tackle prion diseases or other protein misfolding disorders.

Cellular prion protein offers neuroprotection in astrocytes submitted to amyloid ß oligomer toxicity.

The cellular prion protein (PrPC), in its native conformation, performs numerous cellular and cognitive functions in brain tissue. However, despite the cellular prion research in recent years, there are still questions about its participation in oxidative and neurodegenerative processes. This study aims to elucidate the involvement of PrPC in the neuroprotection cascade in the presence of oxidative stressors. For that, astrocytes from wild-type mice and knockout to PrPC were subjected to the induction of oxidative stress with hydrogen peroxide (H2O2) and with the toxic oligomer of the amyloid ß protein (AßO). We observed that the presence of PrPC showed resistance in the cell viability of astrocytes. It was also possible to monitor changes in basic levels of metals and associate them with an induced damage condition, indicating the precise role of PrPC in metal homeostasis, where the absence of PrPC leads to metallic unbalance, culminating in cellular vulnerability to oxidative stress. Increased caspase 3, p-Tau, p53, and Bcl2 may establish a relationship between a PrPC and an induced damage condition. Complementarily, it has been shown that PrPC prevents the internalization of AßO and promotes its degradation under oxidative stress induction, thus preventing protein aggregation in astrocytes. It was also observed that the presence of PrPC can be related to translocating SOD1 to cell nuclei under oxidative stress, probably controlling DNA damage. The results of this study suggest that PrPC acts against oxidative stress activating the cellular response and defense by displaying neuroprotection to neurons and ensuring the functionality of astrocytes.

Comparative analysis of PRNP 12-bp and 23-bp indels in healthy Aberdeen Angus, Aberdeen Angus x Hereford, Holstein Friesian and Uruguayan Creole cattle / Análise comparativa de PRNP 12bp e 23bp indels em bovinos Aberdeen Angus, Aberdeen Angus x Hereford, Holstein Friesian e Crioulo Uruguaio saudáveis

Bovine spongiform encephalopathy (BSE) is a transmissible progressive neurodegenerative disease characterized by the accumulation of a pathological isoform (PrpSC) of the cellular prion protein (PrpC) in the brain of cattle. Two insertion/deletion polymorphisms in the PRNP gene (23bp in the promoter and 12bp in intron 1) have been associated with resistance or susceptibility to the disease. The aim of this study was to analyze the distribution of these polymorphisms in 214 healthy bovines belonging to four different breed groups (Aberdeen Angus, Aberdeen Angus x Hereford, Holstein Friesian and Uruguayan Creole cattle). DNA samples were amplified by end-point PCR. A high frequency of the alleles and haplotype associated with susceptibility to BSE (del12 and del23, and del12-del23, respectively) were found in the Aberdeen Angus, Aberdeen Angus x Hereford and Holstein Friesian animals. At the same time, the Uruguayan Creole cattle presented a higher frequency of the alleles and haplotype associated with resistance to BSE (ins12 and ins23, and ins12-ins23, respectively). These data could indicate a greater genetic resistance of the Uruguayan Creole cattle to BSE compared to other analyzed breeds, reinforcing its value as a zoogenetic resource.

A encefalopatia espongiforme bovina (EEB) é uma doença neurodegenerativa progressiva transmissível dos bovinos, caracterizada pelo acúmulo no cérebro de uma isoforma patológica (PrpSC) da proteína priônica celular (PrpC). Dois polimorfismos de inserção/deleção no gene PRNP (23bp no promotor e 12bp no íntron 1) foram associados à resistência ou suscetibilidade à doença. O objetivo deste trabalho foi analisar a distribuição desses polimorfismos em 214 bovinos sadios, pertencentes a quatro diferentes grupos raciais (Aberdeen Angus, Aberdeen Angus x Hereford, Holstein Friesian e Crioulo Uruguaio). As amostras de DNA foram amplificadas por PCR de tempo final. Uma alta frequência dos alelos e haplótipos associados à suscetibilidade à BSE (del12 e del23 e del12-del23, respectivamente) foram encontrados nos animais Aberdeen Angus, Aberdeen Angus x Hereford e Holstein Friesian, enquanto o gado Crioulo Uruguaio apresentou maior frequência dos alelos e haplótipos associados à resistência à BSE (ins12 e ins23 e ins12-ins23, respectivamente). Esses dados podem indicar uma maior resistência genética do gado Crioulo Uruguaio à BSE em comparação com as outras raças analisadas, reforçando seu valor como recurso zoogenético.

Compromiso sensitivo y polineuropatía periférica como manifestación inicial de enfermedad de Creutzfeldt-Jakob. A propósito de un caso

La enfermedad de Creutzfeldt-Jakob (ECJ) es una rara enfermedad neurodegenerativa con una alta incidencia en Chile respecto del resto del mundo. El cuadro se caracteriza principalmente por desarrollo de demencia rápidamente progresiva y diversos signos neurológicos inespecíficos, siendo el más frecuente la mioclonía. El caso que se describirá a continuación destaca por las manifestaciones iniciales atípicas que presentó el paciente, tales como compromiso sensitivo en región cráneo-cérvico-dorsal y polineuropatía periférica de extremidades inferiores (EEII), lo que significó un retraso en el diagnóstico clínico de la ECJ. Es importante conocer los diferentes síntomas y signos que pueden presentarse en el cuadro clínico de ECJ, tanto típicos como aquellos menos frecuentes, para así poder dar con el diagnóstico de la enfermedad en etapas más tempranas. De igual manera, es fundamental contar con herramientas diagnósticas como la detección de proteína 14-3-3 o proteína Tau en los centros de salud de nuestro país. Esto permitiría al equipo de salud, brindar un manejo de soporte adecuado y oportuno a estos pacientes.

Creutzfeldt-Jakob disease is a rare neurodegenerative disease with a high incidence in Chile compared to the rest of the world. The condition is mainly characterized by the development of rapidly progressive dementia and various nonspecific neurological signs, the most common being myoclonus. The case that will be described below stands out for the atypical initial manifestations that the patient presented, such as sensory compromise in the cranio-cervico-dorsal region and peripheral polyneuropathy of the lower extremities, which meant a delay in the clinical diagnosis of the disease. It is important to know the different symptoms and signs that can be present in the clinical picture of CJD, both typical and those less frequent, in order to be able to diagnose the disease in earlier stages. Similarly, it is essential to have diagnostic tools such as the detection of 14-3-3 protein or Tau protein in health centers in our country. This would allow the health team to provide adequate and timely support management to these patients.

Creutzfeldt-Jakob disease: literature review based on three case reports / Doença de creutzfeldt-jakob: revisão da literatura baseada no relato de três casos

ABSTRACT. Creutzfeldt-Jakob disease (CJD) is one of the transmissible spongiform encephalopathies that lead to rapidly progressive dementia. CJD has a low prevalence, and the average survival is only 1 year after the onset of symptoms. As the patients with CJD develop rapidly progressive dementia, associated with myoclonus, visual or cerebellar problems, pyramidal or extrapyramidal features, and akinetic mutism, the hypothesis of CJD must be raised. Classic magnetic resonance imaging (MRI) findings are hypersignals in the caudate nucleus, putamen, and cortical region. CJD must be considered a differential diagnosis of other types of dementia, and there is no effective treatment for this disease. In this article, we present a literature review based on the report of three cases of the sporadic form of this disease.

RESUMO. A doença de Creutzfeldt-Jakob (DCJ) faz parte do grupo das encefalopatias espongiformes transmissíveis que levam a um quadro de demência rapidamente progressiva. A DCJ possui baixa prevalência, e a sobrevida média é de apenas um ano após o início dos sintomas. Diante de um paciente com demência rapidamente progressiva, associada a mioclonias, alterações visuais ou cerebelares, sinais piramidais ou extrapiramidais e mutismo acinético, a hipótese de DCJ deve ser levantada. Os achados clássicos na ressonância magnética são os hipersinais em núcleo caudado, putâmen e região cortical. A DCJ deve ser considerada como um diagnóstico diferencial de outros tipos de demência e não existe um tratamento eficaz para essa doença. Apresentamos neste artigo uma revisão da literatura baseada no relato de três casos da forma esporádica dessa doença.

Experiencia con la enfermedad de Creutzfeldt-Jakob de un único centro de referencia en México. Análisis de una serie de casos / Experience with Creutzfeldt-Jakob disease in a single referral center in Mexico. Case series

Resumen Introducción: La enfermedad de Creutzfeldt-Jakob (ECJ) es una enfermedad del sistema nervioso central rápidamente progresiva y mortal causada por priones. Objetivo: Presentar las principales características clínicas y paraclínicas de pacientes con probable ECJ en un centro de referencia de América Latina. Métodos: Estudio retrospectivo de pacientes diagnosticados con demencia rápidamente progresiva entre 2014 y 2019. Se incluyeron características clínicas, demográficas, del electroencefalograma, imágenes por resonancia magnética, proteína 14-3-3 y tomografía por emisión de positrones (PET), cuando estaba disponible. Resultados: Veinticuatro pacientes cumplieron con los criterios de ECJ esporádica (75 % mujeres), la edad media fue de 59.29 ± 11.67 años, la duración de la enfermedad desde el inicio de los síntomas hasta el ingreso hospitalario fue de 7.41 ± 6.54 meses y las primeras manifestaciones más comunes fueron las alteraciones del comportamiento (41.7 %). Los complejos de ondas delta prevalecieron en el electroencefalograma (54.2 %), la hiperintensidad cortical en la resonancia magnética (83.3 %) y el hipometabolismo frontal en la PET (37.5 %). En el análisis del líquido cefalorraquídeo, siete casos mostraron proteína tau total positiva; cinco, proteína 14-3-3 positiva; y tres, proteína tau hiperfosforilada positiva. Conclusiones: Existe importante heterogeneidad clínica en cuanto a los síntomas iniciales. Los hallazgos de las pruebas auxiliares coincidieron con los de otras series.

Abstract Introduction: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive and fatal central nervous system disease caused by prions. Objective: To present the main clinical and paraclinical characteristics of patients with probable CJD in a referral center of Latin America. Methods: Retrospective study of patients diagnosed with rapidly progressive dementia between 2014 and 2019. Clinical, demographic, electroencephalogram, magnetic resonance imaging, and 14-3-3 protein characteristics were included, as well as positron-emission tomography (PET) data when available. Results: Twenty-four patients met the criteria for sporadic CJD (75% were women). Mean age was 59.29 ± 11.67 years, while mean disease duration from symptom onset to hospital admission was 7.41 ± 6.54 months. The most common first symptom was behavioral changes (41.7%). Delta wave complexes prevailed (54.2%) on electroencephalogram, cortical hyperintensity (83.3%) on magnetic resonance and frontal hypometabolism (37.5%) on PET. Seven cases showed positive total Tau; five, positive 14-3-3 protein; and three, positive phosphorylated tau on cerebrospinal fluid analysis. Conclusions: There is significant clinical heterogeneity regarding initial symptoms. Auxiliary test findings were consistent with those of other series.

Aminoquinolones and Their Benzoquinone Dimer Hybrids as Modulators of Prion Protein Conversion.

Prion Diseases or Transmissible Spongiform Encephalopathies are neurodegenerative conditions associated with a long incubation period and progressive clinical evolution, leading to death. Their pathogenesis is characterized by conformational changes of the cellular prion protein-PrPC-in its infectious isoform-PrPSc-which can form polymeric aggregates that precipitate in brain tissues. Currently, there are no effective treatments for these diseases. The 2,5-diamino-1,4-benzoquinone structure is associated with an anti-prion profile and, considering the biodynamic properties associated with 4-quinolones, in this work, 6-amino-4-quinolones derivatives and their respective benzoquinone dimeric hybrids were synthesized and had their bioactive profile evaluated through their ability to prevent prion conversion. Two hybrids, namely, 2,5-dichloro-3,6-bis((3-carboxy-1-pentyl-4-quinolone-6-yl)amino)-1,4-benzoquinone (8e) and 2,5-dichloro-3,6-bis((1-benzyl-3-carboxy-4-quinolone-6-yl)amino)-1,4-benzoquinone (8f), stood out for their prion conversion inhibition ability, affecting the fibrillation process in both the kinetics-with a shortening of the lag phase-and thermodynamics and their ability to inhibit the formation of protein aggregates without significant cytotoxicity at ten micromolar.

Diagnostic approach in a patient with Creutzfeldt-Jakob disease / Abordagem diagnóstica em uma paciente com doença de Creutzfeldt-Jakob

ABSTRACT Prion diseases are an important cause of rapidly progressive dementias. Among them, the most common is sporadic Creutzfeldt-Jakob disease (CJD). It is a rare and incurable disease, with rapid progression to death. Objective: To describe the diagnostic approach of a patient with Creutzfeldt-Jakob disease. Methods: The diagnosis is established through the clinical picture associated with characteristic changes in the brain magnetic resonance imaging, the electroencephalogram, and analysis of specific changes in the cerebrospinal fluid. Results: The present report describes the case of a 53-year-old patient in the city of Fortaleza-CE. The diagnosis was made based on the clinical condition and through diagnostic tests, including 14-3-3 protein and RT QUIC analysis. Differential diagnosis was performed with other rapidly progressive causes, such as infectious and immune-mediated diseases. Conclusions: The diagnosis of probable sporadic CJD was established.

RESUMO As doenças priônicas são uma importante causa de demências rapidamente progressivas. Entre elas, a mais comum é a doença de Creutzfeldt-Jakob (DCJ) esporádica. É uma enfermidade rara e incurável, com rápida progressão para óbito. Objetivo: Descrever a abordagem diagnóstica de uma paciente com doença de Creutzfeldt-Jakob. Métodos: O diagnóstico é estabelecido pelo quadro clínico associado a alterações características na ressonância magnética cerebral, no eletroencefalograma e pela análise de alterações específicas no líquido cefalorraquidiano. Resultados: O presente relato descreve o caso de um paciente de 53 anos na cidade de Fortaleza (CE). O diagnóstico foi feito com base na condição clínica e por meio de testes diagnósticos, incluindo proteína 14-3-3 e análise Real-Time Quaking-Induced Conversion (RT QUIC). O diagnóstico diferencial foi realizado com outras causas rapidamente progressivas, como doenças infecciosas e imunomediadas. Conclusões: Por fim, foi estabelecido o diagnóstico de provável DCJ esporádica.

Systematic review of pharmacological management in Creutzfeldt-Jakob disease: no options so far? / Revisão sistemática do manejo farmacológico na doença de Creutzfeldt-Jakob: ainda sem opções?

Abstract Background The Creutzfeldt-Jakob disease (CJD) is a spongiform encephalopathy that manifests as a rapidly progressive dementia syndrome. Currently, CJD has no cure, and many patients die within the first year, but some drugs are being studied as options for managing this condition. Objective To evaluate the effectiveness of pharmacological treatments offered to patients with CJD as a means to increase survival and reduce cognitive deterioration. Methods A systematic review of the literature was performed using 4 independent reviewers and 1 extra reviewer to resolve possible divergences in the search and analysis of papers indexed in MedLINE (PubMed), SciELO and Lilacs databases. The Medical Subject Heading (MeSH) terms used were: prion diseases, Creutzfeldt-Jakob disease, pharmacologic therapy, therapeutics, quinacrine, doxycycline, flupirtine, and pentosan polysulfate, with the Boolean operators AND and OR. This search included controlled clinical trials, uncontrolled clinical trials, and case series published from the year 2000 onwards, in the English language. Results A total of 85 papers were found using the descriptors used. At the end of the selection analyses, 9 articles remained, which were analyzed fully and individually. Conclusions None of the drugs evaluated proved significantly effective in increasing survival in patients with CJD. Flupirtine appears to have a beneficial effect in reducing cognitive deterioration in patients with CJD. However, additional studies are needed to establish better evidence and therapeutic options for the management of patients with CJD.

Resumo Antecedentes A doença de Creutzfeldt-Jakob (DCJ) é uma encefalopatia espongiforme que se manifesta como síndrome demencial rapidamente progressiva. Atualmente, a DCJ não possui cura e muitos pacientes morrem no primeiro ano de doença, mas alguns medicamentos vêm sendo estudados como opções no manejo desta condição. Objetivo Avaliar a eficácia dos tratamentos farmacológicos oferecidos aos pacientes com DCJ no aumento de sobrevida e na redução da deterioração cognitiva. Métodos Foi realizada uma revisão sistemática da literatura utilizando 4 revisores independentes e 1 extra para resolver divergências eventuais na busca e na análise de trabalhos indexados nas bases de dados MedLINE (via PubMed), SciELO e Lilacs. Os termos Medical Subjects Heading (MeSH) utilizados foram: prion diseases, creutzfeldt jakob disease, pharmacologic therapy, therapeutics, quinacrine, doxycycline, flupirtine e pentosan polysulfate, com os operadores booleanos AND e OR. Essa pesquisa incluiu ensaios clínicos controlados, não controlados e séries de casos, publicados a partir do ano 2000 no idioma inglês. Resultados Ao todo, foram encontrados 85 trabalhos através dos descritores utilizados. Ao final das análises de seleção, restaram 9 artigos, que foram analisados na íntegra individualmente. Conclusões Nenhuma das drogas avaliadas se mostrou significativamente eficaz no aumento da sobrevida dos pacientes com DCJ. A flupirtina parece ter um efeito benéfico na redução da deterioração cognitiva dos pacientes com DCJ. Entretanto, estudos adicionais são necessários para o estabelecimento de melhores evidências e opções terapêuticas para o manejo dos pacientes com DCJ.

The modulation of neuroinflammation by inducible nitric oxide synthase.

The accumulation and propagation of misfolded proteins in the brain is a pathological hallmark shared by many neurodegenerative diseases, such as the depositions of ß-amyloid and hyperphosphorylated tau proteins in Alzheimer's disease. Initial evidence shows the role of nitric oxide synthases in the development of neurodegenerative diseases. A recent, in an exciting paper (Bourgognon et al. in Proc Natl Acad Sci USA 118, 1-11, 2021. 10.1073/pnas.2009579118) it was shown that the inducible nitric oxide synthase plays an important role in promoting oxidative and nitrergic stress leading to neuroinflammation and consequently neuronal function impairments and decline in synaptic strength in mouse prion disease. In this context, we reviewed the possible mechanisms of nitric oxide synthase in the generation of neurodegenerative diseases.