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1.
Nat Immunol ; 24(7): 1110-1123, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37248420

RESUMEN

Cerebrovascular injury (CVI) is a common pathology caused by infections, injury, stroke, neurodegeneration and autoimmune disease. Rapid resolution of a CVI requires a coordinated innate immune response. In the present study, we sought mechanistic insights into how central nervous system-infiltrating monocytes program resident microglia to mediate angiogenesis and cerebrovascular repair after an intracerebral hemorrhage. In the penumbrae of human stroke brain lesions, we identified a subpopulation of microglia that express vascular endothelial growth factor A. These cells, termed 'repair-associated microglia' (RAMs), were also observed in a rodent model of CVI and coexpressed interleukin (IL)-6Ra. Cerebrovascular repair did not occur in IL-6 knockouts or in mice lacking microglial IL-6Ra expression and single-cell transcriptomic analyses revealed faulty RAM programming in the absence of IL-6 signaling. Infiltrating CCR2+ monocytes were the primary source of IL-6 after a CVI and were required to endow microglia with proliferative and proangiogenic properties. Faulty RAM programming in the absence of IL-6 or inflammatory monocytes resulted in poor cerebrovascular repair, neuronal destruction and sustained neurological deficits that were all restored via exogenous IL-6 administration. These data provide a molecular and cellular basis for how monocytes instruct microglia to repair damaged brain vasculature and promote functional recovery after injury.


Asunto(s)
Monocitos , Accidente Cerebrovascular , Ratones , Humanos , Animales , Microglía , Interleucina-6/genética , Interleucina-6/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Accidente Cerebrovascular/patología , Encéfalo/metabolismo , Ratones Endogámicos C57BL
2.
Nat Immunol ; 22(10): 1280-1293, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34556874

RESUMEN

Traumatic brain injury (TBI) and cerebrovascular injury are leading causes of disability and mortality worldwide. Systemic infections often accompany these disorders and can worsen outcomes. Recovery after brain injury depends on innate immunity, but the effect of infections on this process is not well understood. Here, we demonstrate that systemically introduced microorganisms and microbial products interfered with meningeal vascular repair after TBI in a type I interferon (IFN-I)-dependent manner, with sequential infections promoting chronic disrepair. Mechanistically, we discovered that MDA5-dependent detection of an arenavirus encountered after TBI disrupted pro-angiogenic myeloid cell programming via induction of IFN-I signaling. Systemic viral infection similarly blocked restorative angiogenesis in the brain parenchyma after intracranial hemorrhage, leading to chronic IFN-I signaling, blood-brain barrier leakage and a failure to restore cognitive-motor function. Our findings reveal a common immunological mechanism by which systemic infections deviate reparative programming after central nervous system injury and offer a new therapeutic target to improve recovery.


Asunto(s)
Antiinfecciosos/inmunología , Lesiones Traumáticas del Encéfalo/inmunología , Sistema Nervioso Central/inmunología , Inmunidad Innata/inmunología , Animales , Barrera Hematoencefálica/inmunología , Encéfalo/inmunología , Modelos Animales de Enfermedad , Femenino , Interferón Tipo I/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Transducción de Señal/inmunología
3.
Nat Immunol ; 20(4): 407-419, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30886419

RESUMEN

Tissue macrophages have an embryonic origin and can be replenished in some tissues under steady-state conditions by blood monocytes. However, little is known about the residency and properties of infiltrating monocytes after an inflammatory challenge. The meninges of the central nervous system (CNS) are populated by a dense network of macrophages that act as resident immune sentinels. Here we show that, following lymphocytic choriomeningitis virus infection, resident meningeal macrophages (MMs) acquired viral antigen and interacted directly with infiltrating cytotoxic T lymphocytes, which led to macrophage depletion. Concurrently, the meninges were infiltrated by inflammatory monocytes that engrafted the meningeal niche and remained in situ for months after viral clearance. This engraftment led to interferon-γ-dependent functional changes in the pool of MMs, including loss of bacterial and immunoregulatory sensors. Collectively, these data indicate that peripheral monocytes can engraft the meninges after an inflammatory challenge, imprinting the compartment with long-term defects in immune function.


Asunto(s)
Sistema Nervioso Central/inmunología , Macrófagos/inmunología , Meningitis Viral/inmunología , Monocitos/inmunología , Animales , Inmunidad , Inflamación/inmunología , Interferón gamma/fisiología , Meninges/inmunología , Ratones
4.
EMBO J ; 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39379554

RESUMEN

Mitochondrial dysfunction causes devastating disorders, including mitochondrial myopathy, but how muscle senses and adapts to mitochondrial dysfunction is not well understood. Here, we used diverse mouse models of mitochondrial myopathy to show that the signal for mitochondrial dysfunction originates within mitochondria. The mitochondrial proteins OMA1 and DELE1 sensed disruption of the inner mitochondrial membrane and, in response, activated the mitochondrial integrated stress response (mt-ISR) to increase the building blocks for protein synthesis. In the absence of the mt-ISR, protein synthesis in muscle was dysregulated causing protein misfolding, and mice with early-onset mitochondrial myopathy failed to grow and survive. The mt-ISR was similar following disruptions in mtDNA maintenance (Tfam knockout) and mitochondrial protein misfolding (CHCHD10 G58R and S59L knockin) but heterogenous among mitochondria-rich tissues, with broad gene expression changes observed in heart and skeletal muscle and limited changes observed in liver and brown adipose tissue. Taken together, our findings identify that the DELE1 mt-ISR mediates a similar response to diverse forms of mitochondrial stress and is critical for maintaining growth and survival in early-onset mitochondrial myopathy.

5.
Nature ; 597(7878): 709-714, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34497421

RESUMEN

Multiple sclerosis (MS) lesions that do not resolve in the months after they form harbour ongoing demyelination and axon degeneration, and are identifiable in vivo by their paramagnetic rims on MRI scans1-3. Here, to define mechanisms underlying this disabling, progressive neurodegenerative state4-6 and foster development of new therapeutic agents, we used MRI-informed single-nucleus RNA sequencing to profile the edge of demyelinated white matter lesions at various stages of inflammation. We uncovered notable glial and immune cell diversity, especially at the chronically inflamed lesion edge. We define 'microglia inflamed in MS' (MIMS) and 'astrocytes inflamed in MS', glial phenotypes that demonstrate neurodegenerative programming. The MIMS transcriptional profile overlaps with that of microglia in other neurodegenerative diseases, suggesting that primary and secondary neurodegeneration share common mechanisms and could benefit from similar therapeutic approaches. We identify complement component 1q (C1q) as a critical mediator of MIMS activation, validated immunohistochemically in MS tissue, genetically by microglia-specific C1q ablation in mice with experimental autoimmune encephalomyelitis, and therapeutically by treating chronic experimental autoimmune encephalomyelitis with C1q blockade. C1q inhibition is a potential therapeutic avenue to address chronic white matter inflammation, which could be monitored by longitudinal assessment of its dynamic biomarker, paramagnetic rim lesions, using advanced MRI methods.


Asunto(s)
Astrocitos/patología , Linfocitos/patología , Microglía/patología , Esclerosis Múltiple/patología , Animales , Encéfalo/patología , Complemento C1q/antagonistas & inhibidores , Complemento C1q/metabolismo , Encefalomielitis Autoinmune Experimental/patología , Femenino , Humanos , Inflamación/patología , Imagen por Resonancia Magnética , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Esclerosis Múltiple/diagnóstico por imagen , RNA-Seq , Transcriptoma , Sustancia Blanca/patología
6.
J Neurosci ; 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39214704

RESUMEN

Neuregulin1 (Nrg1) signaling is critical for aspects of neuronal development and function from fate specification to synaptic plasticity. Type III Nrg1 is a synaptic protein which engages in bi-directional signaling with its receptor ErbB4. Forward signaling engages ErbB4 phosphorylation, whereas back signaling engages two known mechanisms: 1. local axonal PI3K-AKT signaling, and 2. cleavage by gamma secretase resulting in cytosolic release of the intracellular domain (ICD), which can traffic to the nucleus (Bao, Wolpowitz et al. 2003, Hancock, Canetta et al. 2008). To dissect the contribution of these alternate signaling strategies to neuronal development we generated a transgenic mouse with a missense mutation (V321L) in the Nrg1 transmembrane domain that disrupts nuclear back signaling with minimal effects on forward signaling or local back-signaling and was previously found to be associated with psychosis (Walss-Bass, Liu et al. 2006). We combined RNA sequencing, retroviral fate mapping of neural stem cells, behavioral analyses, and various network analyses of transcriptomic data to investigate the effect of disrupting Nrg1 nuclear back-signaling in the dentate gyrus (DG) of male and female mice.The V321L mutation impairs nuclear translocation of the Nrg1 ICD and alters gene expression in the DG. V321L mice show reduced stem cell proliferation, altered cell cycle dynamics, fate specification defects, and dendritic dysmorphogenesis. Orthologs of known schizophrenia (SCZ)-susceptibility genes were dysregulated in the V321L DG. These genes coordinated a larger network with other dysregulated genes. WGCNA and protein-interaction network analyses revealed striking similarity between DG transcriptomes of V321L mouse and humans with schizophrenia.Significance statement Synaptic contact is predicted to be a regulator of the generation of nuclear signaling by Nrg1. Here we show that a schizophrenia-associated mutation in Nrg1 disrupts its ability to communicate extracellular signals to the neuronal genome which results in altered expression of a gene network enriched for orthologs of schizophrenia-susceptibility genes. The striking overlap in functional and molecular alterations between a single rare homozygous missense mutation (V321L) and schizophrenia patient data (complex polygenic and environmental burden) underscores potential convergence of rare and common variants on the same cellular and molecular phenotypes. Furthermore, our data indicate that the evolutionarily conserved gene networks that form the basis for this risk are necessary for coordinating neurodevelopmental events in the DG.

7.
J Neurosci ; 43(19): 3582-3597, 2023 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-37037607

RESUMEN

Regional cellular heterogeneity is a fundamental feature of the human neocortex; however, details of this heterogeneity are still undefined. We used single-nucleus RNA-sequencing to examine cell-specific transcriptional features in the dorsolateral PFC (DLPFC) and the subgenual anterior cingulate cortex (sgACC), regions implicated in major psychiatric disorders. Droplet-based nuclei-capture and library preparation were performed on replicate samples from 8 male donors without history of psychiatric or neurologic disorder. Unsupervised clustering identified major neural cell classes. Subsequent iterative clustering of neurons further revealed 20 excitatory and 22 inhibitory subclasses. Inhibitory cells were consistently more abundant in the sgACC and excitatory neuron subclusters exhibited considerable variability across brain regions. Excitatory cell subclasses also exhibited greater within-class transcriptional differences between the two regions. We used these molecular definitions to determine which cell classes might be enriched in loci carrying a genetic signal in genome-wide association studies or for differentially expressed genes in mental illness. We found that the heritable signals of psychiatric disorders were enriched in neurons and that, while the gene expression changes detected in bulk-RNA-sequencing studies were dominated by glial cells, some alterations could be identified in specific classes of excitatory and inhibitory neurons. Intriguingly, only two excitatory cell classes exhibited concomitant region-specific enrichment for both genome-wide association study loci and transcriptional dysregulation. In sum, by detailing the molecular and cellular diversity of the DLPFC and sgACC, we were able to generate hypotheses on regional and cell-specific dysfunctions that may contribute to the development of mental illness.SIGNIFICANCE STATEMENT Dysfunction of the subgenual anterior cingulate cortex has been implicated in mood disorders, particularly major depressive disorder, and the dorsolateral PFC, a subsection of the PFC involved in executive functioning, has been implicated in schizophrenia. Understanding the cellular composition of these regions is critical to elucidating the neurobiology underlying psychiatric and neurologic disorders. We studied cell type diversity of the subgenual anterior cingulate cortex and dorsolateral PFC of humans with no neuropsychiatric illness using a clustering analysis of single-nuclei RNA-sequencing data. Defining the transcriptomic profile of cellular subpopulations in these cortical regions is a first step to demystifying the cellular and molecular pathways involved in psychiatric disorders.


Asunto(s)
Trastorno Depresivo Mayor , Corteza Prefontal Dorsolateral , Humanos , Masculino , Trastorno Depresivo Mayor/metabolismo , Giro del Cíngulo/metabolismo , Corteza Prefrontal/fisiología , Estudio de Asociación del Genoma Completo , Núcleo Solitario/metabolismo
8.
J Gen Intern Med ; 2024 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-39327343

RESUMEN

BACKGROUND: Enhancing residency recruitment with modifications to interviews has been an area of national interest, further catalyzed by the transition to universal virtual interviewing (UVI). In 2018, our internal medicine residency program redesigned the recruitment process using virtual interviews. OBJECTIVE: Evaluating this recruitment model allows programs to identify applicant perceptions of each component as they consider enhancements. DESIGN: The new model, termed "SPLIT," included separating optional applicant visit days (AVD) from interviews (S), a pre-interview supplemental form (P), learning program information from a dedicated website (L), virtual interviews (I), and flexible timing (remote interview day and site visit) (T). PARTICIPANTS: Applicants for the 2019 to 2023 Match who interviewed at one university-based internal medicine residency program. MAIN MEASURES: After rank list certification and before the annual Match, interviewed applicants were surveyed regarding their perceptions of the SPLIT process. Responses before (2019-2020 Matches) and after (2021-2023 Matches) UVIs were compared. KEY RESULTS: A total of 386 (75%) of 515 respondents favored video interviews. This preference was stronger in the post-UVI group (92%) than in the pre-UVI group (57%) (p < 0.001). In total, 76% of respondents attended an AVD (virtual or in-person). Applicants in the post-UVI group also favored having interviews separated from the AVD (p = 0.006) and optional AVDs (p < 0.001), more than those in the pre-UVI group. In the pre-UVI cohort, those who attended an in-person AVD tended to report a higher program understanding (OR 7.8), satisfaction with SPLIT (OR 2.1), and a better recruitment experience (OR 2.0). CONCLUSIONS: Virtual interviews were highly rated with increased preference following universal adoption. Optional AVDs separated from virtual interviews enhance applicant understanding of the program and were more effective when offered in-person before the pandemic-related restrictions. As programs begin to reintroduce in-person elements, the SPLIT recruitment model offers an innovative approach that addresses applicant and program needs.

9.
Alzheimers Dement ; 20(8): 5220-5235, 2024 08.
Artículo en Inglés | MEDLINE | ID: mdl-38923692

RESUMEN

INTRODUCTION: Variants of uncertain significance (VUS) surged with affordable genetic testing, posing challenges for determining pathogenicity. We examine the pathogenicity of a novel VUS P93S in Annexin A11 (ANXA11) - an amyotrophic lateral sclerosis/frontotemporal dementia-associated gene - in a corticobasal syndrome kindred. Established ANXA11 mutations cause ANXA11 aggregation, altered lysosomal-RNA granule co-trafficking, and transactive response DNA binding protein of 43 kDa (TDP-43) mis-localization. METHODS: We described the clinical presentation and explored the phenotypic diversity of ANXA11 variants. P93S's effect on ANXA11 function and TDP-43 biology was characterized in induced pluripotent stem cell-derived neurons alongside multiomic neuronal and microglial profiling. RESULTS: ANXA11 mutations were linked to corticobasal syndrome cases. P93S led to decreased lysosome colocalization, neuritic RNA, and nuclear TDP-43 with cryptic exon expression. Multiomic microglial signatures implicated immune dysregulation and interferon signaling pathways. DISCUSSION: This study establishes ANXA11 P93S pathogenicity, broadens the phenotypic spectrum of ANXA11 mutations, underscores neuronal and microglial dysfunction in ANXA11 pathophysiology, and demonstrates the potential of cellular models to determine variant pathogenicity. HIGHLIGHTS: ANXA11 P93S is a pathogenic variant. Corticobasal syndrome is part of the ANXA11 phenotypic spectrum. Hybridization chain reaction fluorescence in situ hybridization (HCR FISH) is a new tool for the detection of cryptic exons due to TDP-43-related loss of splicing regulation. Microglial ANXA11 and related immune pathways are important drivers of disease. Cellular models are powerful tools for adjudicating variants of uncertain significance.


Asunto(s)
Anexinas , Proteínas de Unión al ADN , Humanos , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Anexinas/genética , Masculino , Mutación/genética , Femenino , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/patología , Neuronas/metabolismo , Neuronas/patología , Demencia Frontotemporal/genética , Demencia Frontotemporal/patología , Persona de Mediana Edad , Anciano
10.
J Orthop Traumatol ; 25(1): 25, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38727945

RESUMEN

BACKGROUND: Acetabular cup positioning in total hip arthroplasty (THA) is closely related to outcomes. The literature has suggested cup parameters defined by the Lewinnek safe zone; however, the validity of such measures is in question. Several studies have raised concerns about the benefits of using the Lewinnek safe zone as a predictor of success. In this study we elected to use prospective surgeon targets as the basis for comparison to see how successful surgeons are positioning their cup using standard instruments and techniques. METHODS: A prospective, global, multicenter study was conducted. Cup positioning success was defined as a composite endpoint. Both cup inclination and version needed to be within 10° of the surgeon target to be considered a success. Radiographic analysis was conducted by a third-party reviewer. RESULTS: In 170 subjects, inclination, target versus actual, was 44.8° [standard deviation (SD 0.9°)] and 43.1° (SD 7.6°), respectively (p = 0.0029). Inclination was considered successful in 84.1% of cases. Mean version, target versus actual, was 19.4° (SD 3.9°) and 27.2° (SD 5.6°), respectively (p < 0.0001). Version was considered successful in 63.4% of cases, and combined position (inclination and version) was considered successful in 53.1%. CONCLUSION: This study shows that with traditional methods of placing the cup intraoperatively, surgeons are only accurate 53.1% of the time compared with a predicted preoperative plan. This study suggests that the inconsistency in cup positioning based on the surgeon's planned target is potentially another important variable to consider while using a mechanical guide or in freehand techniques for cup placement in THA. TRIAL REGISTRATION: This study is registered on ClinicalTrials.gov, NCT03189303.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Artroplastia de Reemplazo de Cadera/métodos , Artroplastia de Reemplazo de Cadera/instrumentación , Humanos , Estudios Prospectivos , Femenino , Masculino , Anciano , Persona de Mediana Edad , Acetábulo/cirugía
11.
PLoS Pathog ; 17(2): e1009305, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33556144

RESUMEN

Ionizing radiation-induced tissue damage recruits monocytes into the exposed area where they are differentiated to macrophages. These implement phagocytic removal of dying cells and elicit an acute inflammatory response, but can also facilitate tumorigenesis due to production of anti-inflammatory cytokines. Using primary human monocyte-derived macrophages (MDMs) and the THP1 monocytic cell line, we demonstrate that gamma radiation triggers monocyte differentiation toward the macrophage phenotype with increased expression of type I interferons (IFN-I) and both pro- and anti-inflammatory macrophage activation markers. We found that these changes correlate with significantly upregulated expression of 622 retroelements from various groups, particularly of several clades of human endogenous retroviruses (HERVs). Elevated transcription was detected in both sense and antisense directions in the HERV subgroups tested, including the most genetically homogeneous clade HML-2. The level of antisense transcription was three- to five-fold higher than of the sense strand levels. Using a proximity ligation assay and immunoprecipitation followed by RNA quantification, we identified an increased amount of the dsRNA receptors MDA-5 and TLR3 bound to an equivalent number of copies of sense and antisense chains of HERVK HML-2 RNA. This binding triggered MAVS-associated signaling pathways resulting in increased expression of IFN-I and inflammation related genes that enhanced the cumulative inflammatory effect of radiation-induced senescence. HML-2 knockdown was accompanied with reduced expression and secretion of IFNα, pro-inflammatory (IL-1ß, IL-6, CCL2, CCL3, CCL8, and CCL20) and anti-inflammatory (IL10) modulators in irradiated monocytes and MDMs. Taken together, our data indicate that radiation stress-induced HERV expression enhances the IFN-I and cytokine response and results in increased levels of pro-inflammatory modulators along with expression of anti-inflammatory factors associated with the macrophage tumorigenic phenotype.


Asunto(s)
Retrovirus Endógenos/genética , Rayos gamma , Inflamación/inmunología , Activación de Macrófagos/inmunología , Macrófagos/inmunología , Monocitos/inmunología , Retroelementos/genética , Diferenciación Celular , Citocinas/metabolismo , Humanos , Inflamación/metabolismo , Inflamación/patología , Macrófagos/metabolismo , Macrófagos/efectos de la radiación , Monocitos/metabolismo , Monocitos/efectos de la radiación , Transcriptoma
12.
Ann Neurol ; 92(5): 782-792, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36053951

RESUMEN

OBJECTIVES: Reactivation of HERV-K(HML-2) has been found in subsets of individuals with amyotrophic lateral sclerosis (ALS). This study examines the antibody response against HML-2 in ALS and analyzes its clinical relevance. METHODS: Antibodies to HML-2 envelope (env) were analyzed using a peptide array for epitope mapping and by a peptide enzyme-linked immunosorbent assay (ELISA) in 242 healthy donors, and 243 ALS and 85 multiple sclerosis (MS) individuals. Extracellular levels of HML-2 were analyzed by digital polymerase chain reaction (PCR). RESULTS: Antibodies in the sera of ALS individuals recognized more HML-2 env peptides compared to healthy controls (p < 0.0001). ALS individuals had higher levels of HML-2 than healthy donors (p = 0.02) and higher antibody levels against a select HML-2 env peptide compared to healthy donors or individuals with multiple sclerosis (p < 0.0001). 55.14% of ALS compared to 21.16% of healthy donors and 13.10% of MS individuals had antibodies against the HML-2 peptide (AUC = 0.769, p < 0.0001). Levels of extracellular HML-2 DNA in serum (p = 0.02) and the number of HML-2 env peptides recognized by ALS sera (p = 0.02) correlated with disease duration. Among ALS individuals, lower levels of HML-2 antibodies were associated with a definite diagnosis per EL Escorial criteria (p = 0.03), and with a lower predicted (p = 0.02) and observed survival (p = 0.03). INTERPRETATION: There is a differential antibody response against specific epitopes of HML-2 env in ALS and controls, suggesting epitope spreading, likely due to persistent antigenic exposure following reactivation of the viral genes. Low levels of antibodies to HML-2 env in ALS are associated with poor prognosis and decreased survival probability. ANN NEUROL 2022;92:782-792.


Asunto(s)
Esclerosis Amiotrófica Lateral , Esclerosis Múltiple , Humanos , Esclerosis Amiotrófica Lateral/genética , Formación de Anticuerpos , Epítopos , Péptidos
13.
Proc Natl Acad Sci U S A ; 117(30): 17842-17853, 2020 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-32669437

RESUMEN

Stem cells are capable of unlimited proliferation but can be induced to form brain cells. Factors that specifically regulate human development are poorly understood. We found that human stem cells expressed high levels of the envelope protein of an endogenized human-specific retrovirus (HERV-K, HML-2) from loci in chromosomes 12 and 19. The envelope protein was expressed on the cell membrane of the stem cells and was critical in maintaining the stemness via interactions with CD98HC, leading to triggering of human-specific signaling pathways involving mammalian target of rapamycin (mTOR) and lysophosphatidylcholine acyltransferase (LPCAT1)-mediated epigenetic changes. Down-regulation or epigenetic silencing of HML-2 env resulted in dissociation of the stem cell colonies and enhanced differentiation along neuronal pathways. Thus HML-2 regulation is critical for human embryonic and neurodevelopment, while it's dysregulation may play a role in tumorigenesis and neurodegeneration.


Asunto(s)
Diferenciación Celular , Retrovirus Endógenos/fisiología , Neuronas/metabolismo , Transducción de Señal , Células Madre/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Biomarcadores , Diferenciación Celular/genética , Autorrenovación de las Células/genética , Cadena Pesada de la Proteína-1 Reguladora de Fusión/metabolismo , Regulación Viral de la Expresión Génica , Humanos , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Neuronas/citología , Unión Proteica , Células Madre/citología , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas del Envoltorio Viral/genética
14.
J Neurovirol ; 27(1): 126-136, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33462791

RESUMEN

The transactivator of transcription (Tat) is a key HIV regulatory protein. We aimed to identify the frequency of key polymorphisms in HIV-1C compared with HIV-1B Tat protein, chiefly in the cysteine-, arginine-, and glutamine-rich domains and identify novel point mutations in HIV-1B and C sequences from Southern Brazil. This study was the first to investigate the genetic diversity and point mutations within HIV-1 Tat C in a Brazilian cohort. This was an observational, cross-sectional study, which included sequences of HIV-1B (n = 20) and HIV-1C (n = 21) from Southern Brazil. Additionally, 344 HIV-1C sequences were obtained from the Los Alamos database: 29 from Brazil and 315 from Africa, Asia, and Europe. The frequency of C31S substitution on HIV-1 Tat C in Brazil was 82% vs. 10% in the HIV-1B group (p < 0.0001). The frequency of the R57S substitution among the HIV-1C sequences from Brazil was 74% vs. 20% in HIV-1B (p = 0.004), and that of substitution Q63E in HIV-1C was 80% and 20% in HIV-1B (p < 0.0001). The mutation P60Q was more frequent in HIV-1B than in HIV-1C (55% and 6.12%, respectively, p < 0.0001)). Novel point mutations in the HIV-1C and B Tat functional domains were described. The frequency of C31S and other key point mutations in HIV-1 Tat C in Brazil were similar to those described in Africa, although lower than those in India. The Tat-B and C sequences found in Southern Brazil are consistent with biological differences and have potential implications for HIV-1 subtype pathogenesis.


Asunto(s)
VIH-1/genética , Polimorfismo de Nucleótido Simple/genética , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/genética , Adulto , Brasil , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad
15.
FASEB J ; 34(11): 14750-14767, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32910521

RESUMEN

Small ubiquitin-like modifier (SUMO1-3) conjugation (SUMOylation), a posttranslational modification, modulates almost all major cellular processes. Mounting evidence indicates that SUMOylation plays a crucial role in maintaining and regulating neural function, and importantly its dysfunction is implicated in cognitive impairment in humans. We have previously shown that simultaneously silencing SUMO1-3 expression in neurons negatively affects cognitive function. However, the roles of the individual SUMOs in modulating cognition and the mechanisms that link SUMOylation to cognitive processes remain unknown. To address these questions, in this study, we have focused on SUMO2 and generated a new conditional Sumo2 knockout mouse line. We found that conditional deletion of Sumo2 predominantly in forebrain neurons resulted in marked impairments in various cognitive tests, including episodic and fear memory. Our data further suggest that these abnormalities are attributable neither to constitutive changes in gene expression nor to alterations in neuronal morphology, but they involve impairment in dynamic SUMOylation processes associated with synaptic plasticity. Finally, we provide evidence that dysfunction on hippocampal-based cognitive tasks was associated with a significant deficit in the maintenance of hippocampal long-term potentiation in Sumo2 knockout mice. Collectively, these data demonstrate that protein conjugation by SUMO2 is critically involved in cognitive processes.


Asunto(s)
Memoria , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/metabolismo , Animales , Cognición , Femenino , Hipocampo/metabolismo , Hipocampo/fisiología , Potenciación a Largo Plazo , Masculino , Ratones , Ratones Endogámicos C57BL , Prosencéfalo/metabolismo , Prosencéfalo/fisiología , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/genética
16.
J Allergy Clin Immunol ; 145(1): 358-367.e2, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31600545

RESUMEN

BACKGROUND: Thymic hypoplasia/aplasia occurs as a part of DiGeorge syndrome, which has several known genetic causes, and with loss-of-function mutations in forkhead box N1 (FOXN1). OBJECTIVE: We sought to determine the cause of selective T-cell lymphopenia with inverted kappa/lambda ratio in several kindreds. METHODS: Patients were identified through newborn screening for severe combined immunodeficiency using the T-cell receptor excision circle assay. Those found to have selective T-cell lymphopenia underwent testing with chromosomal microarray analysis. Three-week-old mice heterozygous for a loss-of-function mutation in forkhead box I3 (FOXI3), a candidate gene within the common deleted region found in patients, were compared with wild-type littermates. Assessments included body and organ weights, flow cytometric analysis of thymocytes and splenocytes, and histologic/transcriptomic analyses of thymic tissue. RESULTS: Five kindreds with similar immunophenotypes that included selective T-cell lymphopenia had overlapping microdeletions at chromosome 2p11.2 that spanned FOXI3 and, in most cases, the immunoglobulin kappa light chain locus. Studies in a mouse knockout strain for FOXI3 revealed smaller body weights and relatively lower thymus weights in heterozygous compared with wild-type animals. Histology and flow cytometry on spleens and thymi from 3-week-old pups for T- and B-cell subsets and epithelial cells did not show any significant qualitative or quantitative differences. Transcriptomic analysis of thymic RNA revealed divergence in global transcriptomic signatures, and Ingenuity Pathway Analysis revealed predicted dysfunction in epithelial adherens junctions. CONCLUSIONS: Microdeletions at chromosome 2p11.2 are associated with T-cell lymphopenia and probable thymic hypoplasia in human subjects, and haploinsufficiency for FOXI3, a candidate gene within the deleted region, is the likely underlying cause.


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 2/genética , Síndrome de DiGeorge/genética , Factores de Transcripción Forkhead/genética , Mutación con Pérdida de Función , Animales , Cromosomas Humanos Par 2/inmunología , Síndrome de DiGeorge/inmunología , Síndrome de DiGeorge/patología , Femenino , Factores de Transcripción Forkhead/inmunología , Humanos , Masculino , Ratones , Ratones Mutantes , Timo/inmunología , Timo/patología
17.
Int J Mol Sci ; 22(23)2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34884829

RESUMEN

Methylprednisolone (MP) is an anti-inflammatory drug approved for the treatment of acute spinal cord injuries (SCIs). However, MP administration for SCIs has become a controversial issue while the molecular effects of MP remain unexplored to date. Therefore, delineating the benefits and side effects of MP and determining what MP cannot cure in SCIs at the molecular level are urgent issues. Here, genomic profiles of the spinal cord in rats with and without injury insults, and those with and without MP treatment, were generated at 0, 2, 4, 6, 8, 12, 24, and 48 h post-injury. A comprehensive analysis was applied to obtain three distinct classes: side effect of MP (SEMP), competence of MP (CPMP), and incapability of MP (ICMP). Functional analysis using these genes suggested that MP exerts its greatest effect at 8~12 h, and the CPMP was reflected in the immune response, while SEMP suggested aspects of metabolism, such as glycolysis, and ICMP was on neurological system processes in acute SCIs. For the first time, we are able to precisely reveal responsive functions of MP in SCIs at the molecular level and provide useful solutions to avoid complications of MP in SCIs before better therapeutic drugs are available.


Asunto(s)
Antiinflamatorios/farmacología , Metilprednisolona/farmacología , Traumatismos de la Médula Espinal/patología , Transcriptoma/efectos de los fármacos , Animales , Antiinflamatorios/uso terapéutico , Modelos Animales de Enfermedad , Femenino , Metilprednisolona/uso terapéutico , Ratas , Ratas Long-Evans , Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/tratamiento farmacológico , Factores de Tiempo
18.
JAAPA ; 34(7): 32-36, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-34162807

RESUMEN

ABSTRACT: Atopic dermatitis is a chronic inflammatory skin condition that affects patients of all ages. The disease is characterized by xerosis (dry skin) and intensely pruritic lesions distributed throughout the body. This article reviews diagnostic features and treatments for atopic dermatitis.


Asunto(s)
Dermatitis Atópica , Dermatitis Atópica/diagnóstico , Dermatitis Atópica/terapia , Humanos
19.
Ann Neurol ; 86(6): 878-884, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31600832

RESUMEN

OBJECTIVE: JC virus (JCV) infection is a lytic infection of oligodendrocytes in progressive multifocal leukoencephalopathy; less common forms of central nervous system manifestations associated with JCV infection include granule cell neuronopathy, encephalopathy, and meningitis. Presented is the first case of fatal JCV encephalopathy after immunosuppressive therapy that included ruxolitinib. METHODS: Postmortem analysis included next generation sequencing, Sanger sequencing, tissue immunohistochemistry, and formalin-fixed hemisphere 7T magnetic resonance imaging. RESULTS: JCV DNA isolated from postmortem tissue samples identified a novel 12bp insertion that altered the transcription site binding pattern in an otherwise "wild-type virus," which has long been thought to be the nonpathogenic form of JCV. Anti-VP1 staining demonstrated infection in cortical neurons, hippocampal neurons, and glial and endothelial cells. INTERPRETATION: This expands the spectrum of identified JCV diseases associated with broad-spectrum immunosuppression, including JAK-STAT inhibitors, and sheds light on an additional neurotropic virus strain of the archetype variety. ANN NEUROL 2019;86:878-884.


Asunto(s)
Encefalopatías/tratamiento farmacológico , Encefalopatías/genética , Virus JC/genética , Quinasas Janus/genética , Pirazoles/uso terapéutico , Adolescente , Secuencia de Bases , Encefalopatías/diagnóstico por imagen , Resultado Fatal , Femenino , Humanos , Virus JC/aislamiento & purificación , Nitrilos , Pirimidinas
20.
Ann Neurol ; 86(5): 695-703, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31461177

RESUMEN

OBJECTIVE: To determine the underlying etiology in a patient with progressive dementia with extrapyramidal signs and chronic inflammation referred to the National Institutes of Health Undiagnosed Diseases Program. METHODS: Extensive investigations included metabolic profile, autoantibody panel, infectious etiologies, genetic screening, whole exome sequencing, and the phage-display assay, VirScan, for viral immune responses. An etiological diagnosis was established postmortem. RESULTS: Using VirScan, enrichment of dengue viral antibodies was detected in cerebrospinal fluid as compared to serum. No virus was detected in serum or cerebrospinal fluid, but postmortem analysis confirmed dengue virus in the brain by immunohistochemistry, in situ hybridization, quantitative polymerase chain reaction, and sequencing. Dengue virus was also detectable by polymerase chain reaction and sequencing from brain biopsy tissue collected 33 months antemortem, confirming a chronic infection despite a robust immune response directed against the virus. Immunoprofiling and whole exome sequencing of the patient did not reveal any immunodeficiency, and sequencing of the virus demonstrated wild-type dengue virus in the central nervous system. INTERPRETATION: Dengue virus is the most common arbovirus worldwide and represents a significant public health concern. Infections with dengue virus are usually self-limiting, and chronic dengue infections have not been previously reported. Our findings suggest that dengue virus infections may persist in the central nervous system causing a panencephalitis and should be considered in patients with progressive dementia with extrapyramidal features in endemic regions or with relevant travel history. Furthermore, this work highlights the utility of comprehensive antibody profiling assays to aid in the diagnosis of encephalitis of unknown etiology. ANN NEUROL 2019;86:695-703.


Asunto(s)
Dengue/complicaciones , Dengue/patología , Encefalitis Viral/etiología , Encefalitis Viral/patología , Enfermedad Crónica , Demencia , Virus del Dengue , Resultado Fatal , Humanos , Masculino , Persona de Mediana Edad
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