CTBP1 and CTBP2 mutations underpinning neurological disorders: a systematic review.

C-terminal binding proteins (CtBP1/2) are transcriptional coregulators that play a significant role during vertebrate neurodevelopment. This systematic review aims to identify case reports with genetic variants in CTBP1 and CTBP2 associated with brain development syndromes.We screened different databases (PubMed, Scopus, Google Scholar, LILACS) by systematically searching journals and checking reference lists and citations of background papers. We found fourteen cases (10 males) from five papers carrying two pathogenic, heterozygous variants in the CTBP1 gene (13 individuals carried the missense mutation c.991C T, p.Arg342Trp, and one subject carrying the 2-base pair deletion c.1315_1316delCA, p.Gln439ValfsTer84). These mutations were de novo in 13 cases and one case of maternal germinal mosaicism. Two variants are in the same domain of the protein: Pro-Leu-Asp-Leu-Ser (PLDLS) C terminal. Patients with these mutations exhibit a phenotype with intellectual disability, HADDTS syndrome (hypotonia, ataxia, developmental delay, and tooth enamel defects), and cerebellar volume loss. We did not identify reported cases associated with homozygous mutations harbored in CTBP1. We did not identify any report of neurodevelopment phenotypes associated with heterozygous or homozygous CTBP2 mutations. Due to CTBP2/RIBEYE being a gene with dual function, identifying and interpreting the potential pathogenic variants is challenging.Further, homozygous mutations in the CTBP2 gene may be lethal. The mechanisms involved in the pathogenesis of neurodevelopment due to variants of these proteins have not yet been elucidated, despite some functional evidence. Further studies should be conducted to understand these transcription factors and their interaction with each other and their partners.

Single-nucleus RNA sequencing demonstrates an autosomal dominant Alzheimer's disease profile and possible mechanisms of disease protection.

Highly penetrant autosomal dominant Alzheimer's disease (ADAD) comprises a distinct disease entity as compared to the far more prevalent form of AD in which common variants collectively contribute to risk. The downstream pathways that distinguish these AD forms in specific cell types have not been deeply explored. We compared single-nucleus transcriptomes among a set of 27 cases divided among PSEN1-E280A ADAD carriers, sporadic AD, and controls. Autophagy genes and chaperones clearly defined the PSEN1-E280A cases compared to sporadic AD. Spatial transcriptomics validated the activation of chaperone-mediated autophagy genes in PSEN1-E280A. The PSEN1-E280A case in which much of the brain was spared neurofibrillary pathology and harbored a homozygous APOE3-Christchurch variant revealed possible explanations for protection from AD pathology including overexpression of LRP1 in astrocytes, increased expression of FKBP1B, and decreased PSEN1 expression in neurons. The unique cellular responses in ADAD and sporadic AD require consideration when designing clinical trials.

Early Depressive Symptoms Predict Faster Dementia Progression in Autosomal-Dominant Alzheimer's Disease.

BACKGROUND: Depression is associated with Alzheimer's disease (AD). OBJECTIVE: To evaluate the association between depressive symptoms and age of onset of cognitive decline in autosomal dominant AD, and to determine possible factors associated to early depressive symptoms in this population. METHODS: We conducted a retrospective study to identify depressive symptoms among 190 presenilin 1 (PSEN1) E280A mutation carriers, subjected to comprehensive clinical evaluations in up to a 20-year longitudinal follow-up. We controlled for the following potential confounders: APOE, sex, hypothyroidism, education, marital status, residence, tobacco, alcohol, and drug abuse. RESULTS: PSEN1 E280A carriers with depressive symptoms before mild cognitive impairment (MCI) develop dementia faster than E280A carriers without depressive symptoms (Hazard Ratio, HR = 1.95; 95% CI, 1.15-3.31). Not having a stable partner accelerated the onset of MCI (HR = 1.60; 95 % CI, 1.03-2.47) and dementia (HR = 1.68; 95 % CI, 1.09-2.60). E280A carriers with controlled hypothyroidism had later age of onset of depressive symptoms (HR = 0.48; 95 % CI, 0.25-0.92), dementia (HR = 0.43; 95 % CI, 0.21-0.84), and death (HR = 0.35; 95 % CI, 0.13-0.95). APOEɛ2 significantly affected AD progression in all stages. APOE polymorphisms were not associate to depressive symptoms. Women had a higher frequency and developed earlier depressive symptoms than men throughout the illness (HR = 1.63; 95 % CI, 1.14-2.32). CONCLUSION: Depressive symptoms accelerated progress and faster cognitive decline of autosomal dominant AD. Not having a stable partner and factors associated with early depressive symptoms (e.g., in females and individuals with untreated hypothyroidism), could impact prognosis, burden, and costs.

BACE1 and SCD1 are associated with neurodegeneration.

Introduction: Proteolytic processing of amyloid protein precursor by ß-site secretase enzyme (BACE1) is dependent on the cellular lipid composition and is affected by endomembrane trafficking in dementia and Alzheimer's disease (AD). Stearoyl-CoA desaturase 1 (SCD1) is responsible for the synthesis of fatty acid monounsaturation (MUFAs), whose accumulation is strongly associated with cognitive dysfunction. Methods: In this study, we analyzed the relationship between BACE1 and SCD1 in vivo and in vitro neurodegenerative models and their association in familial AD (FAD), sporadic AD (SAD), and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) using microscopy, biochemical, and mass SPECT approach. Results: Our findings showed that BACE1 and SCD1 immunoreactivities were increased and colocalized in astrocytes of the hippocampus in a rat model of global cerebral ischemia (2-VO). A synergistic effect of double BACE1/SCD1 silencing on the recovery of motor and cognitive functions was obtained. This neuroprotective regulation involved the segregation of phospholipids (PLs) associated with polyunsaturated fatty acids in the hippocampus, cerebrospinal fluid, and serum. The double silencing in the sham and ischemic groups was stronger in the serum, inducing an inverse ratio between total phosphatydilcholine (PC) and lysophosphatidylcholine (LPC), represented mainly by the reduction of PC 38:4 and PC 36:4 and an increase in LPC 16:0 and LPC 18:0. Furthermore, PC 38:4 and PC:36:4 levels augmented in pathological conditions in in vitro AD models. BACE1 and SCD1 increases were confirmed in the hippocampus of FAD, SAD, and CADASIL. Conclusion: Therefore, the findings suggest a novel convergence of BACE-1 and SCD1 in neurodegeneration, related to pro-inflammatory phospholipids.

Beta-Secretase 1 Underlies Reactive Astrocytes and Endothelial Disruption in Neurodegeneration.

Dysfunction in the neurovascular unit (NVU) is a key component in the progressive deterioration of Alzheimer's disease (AD) and is critical in vascular dementia. Recent studies have shown that inflammation plays early and perhaps causal roles in the pathogenesis of AD related to NVU damage, possibly in part by overactivating the aspartic acid protease activity of ß-site amyloid precursor protein-cleaving enzyme 1 (BACE1), which until now has almost solely been studied in the context of the ß-amyloid cascade. In this study, we analyzed the relationship of BACE1 with astrocytes and blood vessels in human brains with sporadic and familial dementia [Autosomal dominant cerebral arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), sporadic Alzheimer's disease (SAD), and familial Alzheimer's disease (FAD)] and how BACE1 inhibition affects astrocytes and endothelial cells under conditions of glutamate toxicity. Our results show increased BACE1, PHF (Paired helical filaments)-tau and GFAP (Glial Fibrillary Acid Protein) immunoreactivity (IR) in the CA1 hippocampal regions of FAD and SAD brains. Furthermore, BACE1 immunoprecipitated with GFAP in tissue samples from all study cases, but their immunofluorescence close to (10 µm3) or overlapping blood vessels was only increased in FAD and SAD brains, and PHF-tau was present around the vessels mainly in FAD brains. Interestingly, the increased BACE1 levels were associated with reactive astrocytes, characterized by morphological changes and upregulation of GFAP under pathological and stressful conditions, and endothelial disruption by glutamate excitotoxicity, and these effects were reversed by BACE1 inhibition; further, BACE1-inhibited astrocytes protected endothelial cell integrity by preserving zonula occludens-1 (ZO-1) distribution and decreasing the expression of inflammatory markers. Taken together, these findings suggest that BACE1 dysregulation in astrocytes may have a role in the alterations in NVU integrity implicated in neurodegeneration.

Immunomodulation and Antioxidant Activities as Possible Trypanocidal and Cardioprotective Mechanisms of Major Terpenes from Lippia alba Essential Oils in an Experimental Model of Chronic Chagas Disease.

In the late phase of Trypanosoma cruzi infection, parasite persistence and an exaggerated immune response accompanied by oxidative stress play a crucial role in the genesis of Chronic Chagasic Cardiomyopathy (CCC). Current treatments (Benznidazole (BNZ) and Nifurtimox) can effect only the elimination of the parasite, but are ineffective for late stage treatment and for preventing heart damage and disease progression. In vivo trypanocidal and cardioprotective activity has been reported for Lippia alba essential oils (EOs), ascribed to their two major terpenes, limonene and caryophyllene oxide. To investigate the role of antioxidant and immunomodulatory mechanisms behind these properties, chronic-T. cruzi-infected rats were treated with oral synergistic mixtures of the aforementioned EOs. For this purpose, the EOs were optimized through limonene-enrichment fractioning and by the addition of exogenous caryophyllene oxide (LIMOX) and used alone or in combined therapy with subtherapeutic doses of BNZ (LIMOXBNZ). Clinical, toxicity, inflammatory, oxidative, and parasitological (qPCR) parameters were assessed in cardiac tissue. These therapies demonstrated meaningful antioxidant and immunomodulatory activity on markers involved in CCC pathogenesis (IFN-γ, TNF-α, IL-4, IL-10, and iNOS), which could explain their significant trypanocidal properties and their noteworthy role in preventing, and even reversing, the progression of cardiac damage in chronic Chagas disease.

Heterogeneidad sintomatológica. Perfiles de pacientes diagnosticados con demencia tipo Alzheimer en Antioquia (Colombia) / Symptomatology heterogeneity. Profiles of patients diagnosed with Alzheimer's type dementia in Antioquia (Colombia)

Resumen Objetivo: Describir y contrastar la variabilidad sintomatológica de los casos con demencia tipo Alzheimer esporádico (DTA+E) con los datos obtenidos de los casos con demencia tipo Alzheimer familiar precoz causado por la mutación E280A del Neurobanco del Grupo de Neurociencias de Antioquia (GNA). Materiales y Método: Este estudio fue de tipo exploratorio-descriptivo y correlacional, se tomaron 83 casos de donantes con DTA almacenados en el Neurobanco del GNA. Estos casos se dividen en dos grupos, i) un grupo definido genéticamente como portador de la mutación E280A en el gen de la Presenilina1; y ii) otro grupo no portador de la mutación diagnosticado con Demencia Tipo Alzheimer Esporádico (DTA+E); se contrastaron los marcadores y/o características neuropsiquiatricas, neuropsicológicas, neurológicas y neuropatológicas de ambos grupos. Resultados: El síntoma que mostró mayores diferencias entre ambos grupos fue la repetidera (DTAF E280A fue de 1.2% y el grupo de DTA+E fue 18.4%). Otros síntomas como la depresión o el tiempo de aparición de pérdida progresiva de memoria no mostraron grandes diferencias entre grupos (DTAF E2080A=55.9%; DTA+E =53.1%) y (DTAF E2080A=55.9%; DTA+E =53.1%). Los trastornos del lenguaje que se observaron con mayor frecuencia entre los donantes fueron la pérdida del lenguaje, mutismo, anomia y afasia. El signo de mayor frecuencia en ambos grupos fue descontrol de esfínteres. La atrofia se registró con mayor intensidad en los lóbulos temporales de los cerebros de los donantes con DTA +E (83.3%). Los pesos del cerebro y del contenido de la fosa posterior, tienen una relación moderada, directamente proporcional y altamente significativa desde el punto de vista estadístico. Conclusiones: Existen diferencias neuropatológicas entre DTA+E y E280A que pueden estar asociadas a la fisiopatología de la forma hereditaria de E280A.

Abstract Objective: To describe and contrast the symptomatic variability of cases with sporadic or non-sporadic Alzheimer's dementia (DTA + E) with the data obtained from the cases with early familial Alzheimer's dementia caused by the E280A of the Neurobank of the Neurosciences Group of Antioquia (GNA). Materials and Method: This study was of exploratory - descriptive and correlacional type, 83 donors' cases were taken with DTA stored in the Neurobank. These cases were divided in two groups, i) a group defined genetically like E280A; and ii) another not carrying group of the mutation (DTA+E); the scoreboards and / or characteristics neuropsychiatric, neuropsychological, neurological and neuropathological of both groups were confirmed Results: The symptom that showed higher differences between both groups was iteration (DTAF E280A with 1.2% and 18.4% for the DTA+E group). Other symptoms as depression or the time of appearance of progressive loss of memory did not show big differences among groups (DTAF E2080A=55.9%; DTA+E =53.1%) and (DTAF E2080A=55.9%; DTA+E =53.1%). The language disorders that were observed with major frequency among the donors were the loss of the language, mutism, anomia and aphasia. The sign with higher frequency in both groups was lost of sphincter control. The atrophy was with more intensity in the temporary lobes of the brains of the donors with DTA+E (83.3%). The weight of the brain and of the posterior fosse content, they have a moderate, directly proportional and highly significant relation from the statistical point of view. Conclusions: DTA +E has neuropathological differences with DTAF E280A that can be associated with the physiology hereditary from of DTAF E280A.