Understanding the neurological implications of acute and long COVID using brain organoids.

As early as in the acute phase of the coronavirus disease 2019 (COVID-19) pandemic, the research community voiced concerns about the long-term implications of infection. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), like many other viruses, can trigger chronic disorders that last months or even years. Long COVID, the chronic and persistent disorder lasting more than 12 weeks after the primary infection with SARS-CoV-2, involves a variable number of neurological manifestations, ranging from mild to severe and even fatal. In vitro and in vivo modeling suggest that SARS-CoV-2 infection drives changes within neurons, glia and the brain vasculature. In this Review, we summarize the current understanding of the neuropathology of acute and long COVID, with particular emphasis on the knowledge derived from brain organoid models. We highlight the advantages and main limitations of brain organoids, leveraging their human-derived origin, their similarity in cellular and tissue architecture to human tissues, and their potential to decipher the pathophysiology of long COVID.

APOE4 drives inflammation in human astrocytes via TAGLN3 repression and NF-κB activation.

Apolipoprotein E4 (APOEε4) is the major allelic risk factor for late-onset sporadic Alzheimer's disease (sAD). Inflammation is increasingly considered as critical in sAD initiation and progression. Identifying brain molecular mechanisms that could bridge these two risk factors remain unelucidated. Leveraging induced pluripotent stem cell (iPSC)-based strategies, we demonstrate that APOE controls inflammation in human astrocytes by regulating Transgelin 3 (TAGLN3) expression and, ultimately, nuclear factor κB (NF-κB) activation. We uncover that APOE4 specifically downregulates TAGLN3, involving histone deacetylases activity, which results in low-grade chronic inflammation and hyperactivated inflammatory responses. We show that APOE4 exerts a dominant negative effect to prime astrocytes toward a pro-inflammatory state that is pharmacologically reversible by TAGLN3 supplementation. We further confirm that TAGLN3 is downregulated in the brain of patients with sAD. Our findings highlight the APOE-TAGLN3-NF-κB axis regulating neuroinflammation in human astrocytes and reveal TAGLN3 as a molecular target to modulate neuroinflammation, as well as a potential biomarker for AD.

MT5-MMP promotes neuroinflammation, neuronal excitability and Aß production in primary neuron/astrocyte cultures from the 5xFAD mouse model of Alzheimer's disease.

BACKGROUND: Membrane-type matrix metalloproteinase 5 (MT5-MMP) deficiency in the 5xFAD mouse model of Alzheimer's disease (AD) reduces brain neuroinflammation and amyloidosis, and prevents deficits in synaptic activity and cognition in prodromal stages of the disease. In addition, MT5-MMP deficiency prevents interleukin-1 beta (IL-1ß)-mediated inflammation in the peripheral nervous system. In this context, we hypothesized that the MT5-MMP/IL-1ß tandem could regulate nascent AD pathogenic events in developing neural cells shortly after the onset of transgene activation. METHODS: To test this hypothesis, we used 11-14 day in vitro primary cortical cultures from wild type, MT5-MMP-/-, 5xFAD and 5xFAD/MT5-MMP-/- mice, and evaluated the impact of MT5-MMP deficiency and IL-1ß treatment for 24 h, by performing whole cell patch-clamp recordings, RT-qPCR, western blot, gel zymography, ELISA, immunocytochemistry and adeno-associated virus (AAV)-mediated transduction. RESULTS: 5xFAD cells showed higher levels of MT5-MMP than wild type, concomitant with higher basal levels of inflammatory mediators. Moreover, MT5-MMP-deficient cultures had strong decrease of the inflammatory response to IL-1ß, as well as decreased stability of recombinant IL-1ß. The levels of amyloid beta peptide (Aß) were similar in 5xFAD and wild-type cultures, and IL-1ß treatment did not affect Aß levels. Instead, the absence of MT5-MMP significantly reduced Aß by more than 40% while sparing APP metabolism, suggesting altogether no functional crosstalk between IL-1ß and APP/Aß, as well as independent control of their levels by MT5-MMP. The lack of MT5-MMP strongly downregulated the AAV-induced neuronal accumulation of the C-terminal APP fragment, C99, and subsequently that of Aß. Finally, MT5-MMP deficiency prevented basal hyperexcitability observed in 5xFAD neurons, but not hyperexcitability induced by IL-1ß treatment. CONCLUSIONS: Neuroinflammation and hyperexcitability precede Aß accumulation in developing neural cells with nascent expression of AD transgenes. MT5-MMP deletion is able to tune down basal neuronal inflammation and hyperexcitability, as well as APP/Aß metabolism. In addition, MT5-MMP deficiency prevents IL-1ß-mediated effects in brain cells, except hyperexcitability. Overall, this work reinforces the idea that MT5-MMP is at the crossroads of pathogenic AD pathways that are already incipiently activated in developing neural cells, and that targeting MT5-MMP opens interesting therapeutic prospects.

Deficiency in MT5-MMP Supports Branching of Human iPSCs-Derived Neurons and Reduces Expression of GLAST/S100 in iPSCs-Derived Astrocytes.

For some time, it has been accepted that the ß-site APP cleaving enzyme 1 (BACE1) and the γ-secretase are two main players in the amyloidogenic processing of the ß-amyloid precursor protein (APP). Recently, the membrane-type 5 matrix metalloproteinase (MT5-MMP/MMP-24), mainly expressed in the nervous system, has been highlighted as a new key player in APP-processing, able to stimulate amyloidogenesis and also to generate a neurotoxic APP derivative. In addition, the loss of MT5-MMP has been demonstrated to abrogate pathological hallmarks in a mouse model of Alzheimer's disease (AD), thus shedding light on MT5-MMP as an attractive new therapeutic target. However, a more comprehensive analysis of the role of MT5-MMP is necessary to evaluate how its targeting affects neurons and glia in pathological and physiological situations. In this study, leveraging on CRISPR-Cas9 genome editing strategy, we established cultures of human-induced pluripotent stem cells (hiPSC)-derived neurons and astrocytes to investigate the impact of MT5-MMP deficiency on their phenotypes. We found that MT5-MMP-deficient neurons exhibited an increased number of primary and secondary neurites, as compared to isogenic hiPSC-derived neurons. Moreover, MT5-MMP-deficient astrocytes displayed higher surface area and volume compared to control astrocytes. The MT5-MMP-deficient astrocytes also exhibited decreased GLAST and S100ß expression. These findings provide novel insights into the physiological role of MT5-MMP in human neurons and astrocytes, suggesting that therapeutic strategies targeting MT5-MMP should be controlled for potential side effects on astrocytic physiology and neuronal morphology.

MT5-MMP controls APP and ß-CTF/C99 metabolism through proteolytic-dependent and -independent mechanisms relevant for Alzheimer's disease.

We previously discovered the implication of membrane-type 5-matrix metalloproteinase (MT5-MMP) in Alzheimer's disease (AD) pathogenesis. Here, we shed new light on pathogenic mechanisms by which MT5-MMP controls the processing of amyloid precursor protein (APP) and the fate of amyloid beta peptide (Aß) as well as its precursor C99, and C83. We found in human embryonic kidney cells (HEK) carrying the APP Swedish familial mutation (HEKswe) that deleting the C-terminal non-catalytic domains of MT5-MMP hampered its ability to process APP and release the soluble 95 kDa form (sAPP95). Catalytically inactive MT5-MMP variants increased the levels of Aß and promoted APP/C99 sorting in the endolysosomal system, likely through interactions of the proteinase C-terminal portion with C99. Most interestingly, the deletion of the C-terminal domain of MT5-MMP caused a strong degradation of C99 by the proteasome and prevented Aß accumulation. These discoveries reveal new control of MT5-MMP over APP by proteolytic and non-proteolytic mechanisms driven by the C-terminal domains of the proteinase. The targeting of these non-catalytic domains of MT5-MMP could, therefore, provide new insights into the therapeutic regulation of APP-related pathology in AD.

Emerging Alternative Proteinases in APP Metabolism and Alzheimer's Disease Pathogenesis: A Focus on MT1-MMP and MT5-MMP.

Processing of amyloid beta precursor protein (APP) into amyloid-beta peptide (Aß) by ß-secretase and γ-secretase complex is at the heart of the pathogenesis of Alzheimer's disease (AD). Targeting this proteolytic pathway effectively reduces/prevents pathology and cognitive decline in preclinical experimental models of the disease, but therapeutic strategies based on secretase activity modifying drugs have so far failed in clinical trials. Although this may raise some doubts on the relevance of ß- and γ-secretases as targets, new APP-cleaving enzymes, including meprin-ß, legumain (δ-secretase), rhomboid-like protein-4 (RHBDL4), caspases and membrane-type matrix metalloproteinases (MT-MMPs/η-secretases) have confirmed that APP processing remains a solid mechanism in AD pathophysiology. This review will discuss recent findings on the roles of all these proteinases in the nervous system, and in particular on the roles of MT-MMPs, which are at the crossroads of pathological events involving not only amyloidogenesis, but also inflammation and synaptic dysfunctions. Assessing the potential of these emerging proteinases in the Alzheimer's field opens up new research prospects to improve our knowledge of fundamental mechanisms of the disease and help us establish new therapeutic strategies.

Metalloproteinases and their tissue inhibitors in Alzheimer's disease and other neurodegenerative disorders.

As life expectancy increases worldwide, age-related neurodegenerative diseases will increase in parallel. The lack of effective treatment strategies may soon lead to an unprecedented health, social and economic crisis. Any attempt to halt the progression of these diseases requires a thorough knowledge of the pathophysiological mechanisms involved to facilitate the identification of new targets and the application of innovative therapeutic strategies. The metzincin superfamily of metalloproteinases includes matrix metalloproteinases (MMP), a disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS). These multigenic and multifunctional proteinase families regulate the functions of an increasing number of signalling and scaffolding molecules involved in neuroinflammation, blood-brain barrier disruption, protein misfolding, synaptic dysfunction or neuronal death. Metalloproteinases and their physiological inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), are therefore, at the crossroads of molecular and cellular mechanisms that support neurodegenerative processes, and emerge as potential new therapeutic targets. We provide an overview of current knowledge on the role and regulation of metalloproteinases and TIMPs in four major neurodegenerative diseases: Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and Huntington's disease.

Proamyloidogenic effects of membrane type 1 matrix metalloproteinase involve MMP-2 and BACE-1 activities, and the modulation of APP trafficking.

We previously demonstrated that membrane type 1 (MT1) matrix metalloproteinase (MMP) was up-regulated in the hippocampus of the model of transgenic mice bearing 5 familial mutations on human amyloid precursor protein (APP) and presenilin 1 of Alzheimer disease (AD), and that the proteinase increased the levels of amyloid ß peptide (Aß) and its APP C-terminal fragment of 99 aa in a heterologous cell system. Here we provide further evidence that MT1-MMP interacts with APP and promotes amyloidogenesis in a proteolytic-dependent manner in Swedish APP-expressing human embryonic kidney 293 (HEKswe) cells. MT1-MMP-mediated processing of APP releases a soluble APP fragment, sAPP95. This process partly requires the activation of endogenous MMP-2 but is independent of ß-site APP cleaving enzyme 1 (BACE-1) or α-secretase activities. In contrast, MT1-MMP-mediated increase of Aß levels involved BACE-1 activity and was inhibited by tissue inhibitor of MMP-2, a natural inhibitor of both MT1-MMP and MMP-2. Interestingly, near abolishment of basal Aß production upon BACE-1 inhibition was rescued by MT1-MMP, indicating that the latter could mimic ß-secretase-like activity. Moreover, MT1-MMP promoted APP/Aß localization in endosomes, where Aß production mainly occurs. These data unveil new mechanistic insights to support the proamyloidogenic role of MT1-MMP based on APP processing and trafficking, and reinforce the idea that this proteinase may become a new potential therapeutic target in AD.-Paumier, J.-M., Py, N. A., González, L. G., Bernard, A., Stephan, D., Louis, L., Checler, F., Khrestchatisky, M., Baranger, K., Rivera, S. Proamyloidogenic effects of membrane type 1 matrix metalloproteinase involve MMP-2 and BACE-1 activities, and the modulation of APP trafficking.

Caracterización de la atención psicoterapéutica en la IPS CES Sabaneta, Colombia, 2014-2015 / Characterization of psychotherapeutic assistance in the IPS CES Sabaneta, Colombia, 2014-2015

Resumen Los cambios en la cosmovisión imperante en los últimos decenios han traído consigo sujetos con nuevas características, intereses y exigencias, que han impactado a la psicología clínica en tanto le exigen nuevas formas de comprender e intervenir las problemáticas demandadas por ellos en contextos institucionales, entre otros. De cara a estas nuevas realidades y con el fin de hacer más pertinentes las intervenciones psicoterapéuticas, se realizó una caracterización de las mismas en la Institución Prestadora de Servicios de Salud -IPS- CES Sabaneta (Colombia) durante los años 2014-201 5, a través de un análisis descriptivo de 9.140 registros de atención y 532 historias clínicas elegidas aleatoriamente. Se estudiaron aspectos sociodemográficos, administrativos y teórico-técnicos de la atención a partir de análisis de frecuencia, medidas de tendencia central, de dispersión y de forma. Se encontró que consultan tres hombres por cada mujer, siendo la población entre los 6 y 18 años la que tiene el mayor peso (59,77%). Los trastornos emocionales y del comportamiento fueron el principal diagnóstico (44,92%), seguido por los trastornos neuróticos secundarios a situaciones estresantes y somatomorfos (18,6%). Llama la atención la baja prevalencia de los trastornos de personalidad (0,56%) y que el 48,9% de los pacientes asistió a un máximo de seis sesiones. Los resultados permiten ajustar los perfiles y estrategias de atención de acuerdo con las problemáticas más prevalentes, así como los procesos administrativos y formativos relacionados con ellas.

Abstract The changes happened in the prevailing worldview in the last decades have brought subjects with new characteristics, interests and requirements, which have had an impact on the clinical psychology, as a consequence, they require from clinical psychology new ways of understanding and controlling the arisen issues that concern the institutional contexts. In order to face these realities, relevant psychotherapeutic interventions were implemented through a characterization of health attendance carried out in IPS CES Saba-neta during 2014-201 5, conducted by a descriptive analysis of 9140 records of assistance and an analysis of 532 clinical records, chosen randomly. Sociodemographic, administrative and theoretical-technical aspects of the care service were studied based on frequency analysis, measures of central tendency and dispersion using the SPSS software. It was found that 3 men in 1 woman attend to medical service, being the population between ages of 6 and 18 the one that present the highest weight (59, 77 %). Emotional and behavioral disorders were the main diagnosis (44.92%), followed by neurotic disorders secondary to stressful and somatomorphic situations (18.6%). It is noticed the low prevalence of personality disorders (0.56%) even though 48.9% of patients attended a maximum of six sessions. The results allow adjusting the profiles and care service strategies according to the most prevalent problems, as well as the administrative and formative processes that involve these issues.

[Matricaria chamomilla (aqueous extract) improves atopic dermatitis-like lesions in a murine model]. / Matricaria chamomilla (extracto acuoso) induce mejoría en lesiones tipo-dermatitis atópica en un modelo murino.

BACKGROUND: Matricaria Chamomilla L. (Mch), popularly known as chamomile, has been used for centuries as an herbolary remedy due to its broad clinical spectrum. The aim of this study was to evaluate the effect of Mch associated to a vehicle with emollient function in induced atopic dermatitis (AD)-like lesions in a murine model. METHODS: AD was induced with dinitrochlorobenzene on 12 male seven-week old BALB/c mice. Animals were divided in three groups (control, GC; control negative, GCN; and experimental, GE). Liquid petrolatum was applied to the GCN and liquid petrolatum with aqueous extract of Mch at 7% to the GE. Induction and evolution of the lesions were verified by biopsy at 2nd and 6th week. Evaluation of peripheral blood cells to correlate inflammatory cells was made as well at the same weeks. Lesions were clinically evaluated at 2nd, 4th and 6th week. Scratching was monitored according to the observation methodology of Kobayashi et al. RESULTS: Mch aqueous extract associated to a vehicle with emollient function improves atopic dermatitis-like lesions after two weeks.

INTRODUCCIÓN: Matricaria chamomilla L. (Mch), conocida popularmente como manzanilla, ha sido utilizada por cientos de años como remedio herbolario debido a su amplio espectro en cuanto a sus usos clínicos. El objetivo de este trabajo fue evaluar el efecto de Mch asociada a un vehículo con función emoliente como tratamiento de lesiones tipo-dermatitis atópica (DA) en un modelo murino. MÉTODOS: se indujo DA con dinitroclorobenceno a 12 ratones BALB/c macho de siete semanas de edad, divididos en tres grupos (control, GC; control negativo, GCN y; experimental, GE). Se aplicó petrolato líquido al GCN y petrolato líquido con extracto acuoso de Mch al 7% al GE durante cuatro semanas. La inducción y evolución de las lesiones se corroboraron por biopsia a las dos y seis semanas, analizando sangre periférica en búsqueda de células inflamatorias en los mismos tiempos. Las lesiones fueron evaluadas clínicamente a las dos, cuatro y seis semanas. El rascado se evaluó de acuerdo a la metodología de observación de Kobayashi et al. RESULTADOS: el extracto acuoso liofilizado de Mch asociado a un vehículo con función emoliente demostró mejoría del aspecto de las lesiones tipo DA después de dos semanas.

MT5-MMP Promotes Alzheimer's Pathogenesis in the Frontal Cortex of 5xFAD Mice and APP Trafficking in vitro.

We previously reported that deficiency of membrane-type five matrix metalloproteinase (MT5-MMP) prevents amyloid pathology in the cortex and hippocampus of 5xFAD mice, and ameliorates the functional outcome. We have now investigated whether the integrity of another important area affected in Alzheimer's disease (AD), the frontal cortex, was also preserved upon MT5-MMP deficiency in 4-month old mice at prodromal stages of the pathology. We used the olfactory H-maze (OHM) to show that learning impairment associated with dysfunctions of the frontal cortex in 5xFAD was prevented in bigenic 5xFAD/MT5-MMP-/- mice. The latter exhibited concomitant drastic reductions of amyloid beta peptide (Aß) assemblies (soluble, oligomeric and fibrillary) and its immediate precursor, C99. Simultaneously, astrocyte reactivity and tumor necrosis factor alpha (TNF-α) levels were also lowered. Moreover, MT5-MMP deficiency induced a decrease in N-terminal soluble fragments of amyloid precursor protein (APP), including soluble APPα (sAPPα), sAPPß and the MT5-MMP-linked fragment of 95 kDa, sAPP95. However, the lack of MT5-MMP did not affect the activity of ß- and γ-secretases. In cultured HEKswe cells, transiently expressed MT5-MMP localized to early endosomes and increased the content of APP and Aß40 in these organelles, as well as Aß levels in cell supernatants. This is the first evidence that the pro-amyloidogenic features of MT5-MMP lie, at least in part, on the ability of the proteinase to promote trafficking into one of the amyloidogenic subcellular loci. Together, our data further support the pathogenic role of MT5-MMP in AD and that its inhibition improves the functional and pathological outcomes, in this case in the frontal cortex. These data also support the idea that MT5-MMP could become a novel therapeutic target in AD.