RESUMO
Hydrops fetalis is a rare disorder associated with significant perinatal complications and a high perinatal mortality of at least 50%. Nonimmune hydrops fetalis (NIHF) is more frequent and results from a wide variety of etiologies. One cause of NIHF is lymphatic malformation 6 (LMPHM6) due to biallelic loss-of-function (LoF) variants in PIEZO1. Most individuals are diagnosed postnatally and only few clinical data are available on fetal presentations. We report six novel biallelic predicted LoF variants in PIEZO1 identified by exome sequencing in six fetuses and one deceased neonate from four unrelated families affected with LMPHM6. During the pregnancy, most cases are revealed by isolated NIHF at second trimester of gestation. At post-mortem examination ascites, pleural effusions and telengectasies can guide the etiological diagnosis. We aim to further describe the perinatal presentation of this condition which could be underdiagnosed.
Assuntos
Hidropisia Fetal , Diagnóstico Pré-Natal , Gravidez , Recém-Nascido , Feminino , Humanos , Hidropisia Fetal/diagnóstico , Hidropisia Fetal/genética , Feto , Canais Iônicos/genéticaRESUMO
PURPOSE: We compared the diagnostic yield of fetal clinical exome sequencing (fCES) in prospective and retrospective cohorts of pregnancies presenting with anomalies detected using ultrasound. We evaluated factors that led to a higher diagnostic efficiency, such as phenotypic category, clinical characterization, and variant analysis strategy. METHODS: fCES was performed for 303 fetuses (183 ongoing and 120 ended pregnancies, in which chromosomal abnormalities had been excluded) using a trio/duo-based approach and a multistep variant analysis strategy. RESULTS: fCES identified the underlying genetic cause in 13% (24/183) of prospective and 29% (35/120) of retrospective cases. In both cohorts, recessive heterozygous compound genotypes were not rare, and trio and simplex variant analysis strategies were complementary to achieve the highest possible diagnostic rate. Limited prenatal phenotypic information led to interpretation challenges. In 2 prospective cases, in-depth analysis allowed expansion of the spectrum of prenatal presentations for genetic syndromes associated with the SLC17A5 and CHAMP1 genes. CONCLUSION: fCES is diagnostically efficient in fetuses presenting with cerebral, skeletal, urinary, or multiple anomalies. The comparison between the 2 cohorts highlights the importance of providing detailed phenotypic information for better interpretation and prenatal reporting of genetic variants.
Assuntos
Exoma , Ultrassonografia Pré-Natal , Proteínas Cromossômicas não Histona , Exoma/genética , Feminino , Feto/anormalidades , Feto/diagnóstico por imagem , Humanos , Fosfoproteínas , Gravidez , Diagnóstico Pré-Natal , Estudos Retrospectivos , Sequenciamento do ExomaRESUMO
Neonatal ichthyosis and sclerosing cholangitis (NISCH) syndrome is an extremely rare entity with only 19 patients described in the literature. We report an extended family with the disorder and investigate the association of neurodevelopmental symptoms. Patients with CLDN1 mutations, and specifically « the Moroccan¼ c.200_201delTT deletion, may be an increased risk for neurodevelopmental symptoms such as learning disabilities, mental retardation, and language delay.
Assuntos
Colangite Esclerosante , Ictiose Lamelar , Ictiose , Transtornos Leucocíticos , Alopecia , Colangite Esclerosante/complicações , Colangite Esclerosante/diagnóstico , Colangite Esclerosante/genética , Claudina-1/deficiência , Claudina-1/genética , Humanos , Ictiose/complicações , Ictiose/diagnóstico , Ictiose/genética , Ictiose Lamelar/complicações , Recém-Nascido , Transtornos Leucocíticos/complicações , Transtornos Leucocíticos/genética , SíndromeRESUMO
BACKGROUND: Chronic cerebral hypoperfusion causes damage to the brain's white matter underpinning vascular cognitive impairment. Inflammation and oxidative stress have been proposed as key pathophysiological mechanisms of which the transcription factor Nrf2 is a master regulator. We hypothesised that white matter pathology, microgliosis, blood-brain barrier breakdown and behavioural deficits induced by chronic hypoperfusion would be exacerbated in mice deficient in the transcription factor Nrf2. METHODS: Mice deficient in Nrf2 (male heterozygote or homozygous for Nrf2 knockout) or wild-type littermates on a C57Bl6/J background underwent bilateral carotid artery stenosis (BCAS) to induce chronic cerebral hypoperfusion or sham surgery and survived for a further 6 weeks. White matter pathology was assessed with MAG immunohistochemistry as a marker of altered axon-glial integrity; alterations to astrocytes and microglia/macrophages were assessed with GFAP and Iba1 immunohistochemistry, and blood-brain barrier breakdown was assessed with IgG immunohistochemistry. Behavioural alterations were assessed using 8-arm radial arm maze, and alterations to Nrf2-related and inflammatory-related genes were assessed with qRT-PCR. RESULTS: Chronic cerebral hypoperfusion induced white matter pathology, elevated microglial/macrophage levels and blood-brain barrier breakdown in white matter tracts that were increased in Nrf2+/- mice and further exacerbated by the complete absence of Nrf2. Chronic hypoperfusion induced white matter astrogliosis and induced an impairment in behaviour assessed with radial arm maze; however, these measures were not affected by Nrf2 deficiency. Although Nrf2-related antioxidant gene expression was not altered by chronic cerebral hypoperfusion, there was evidence for elevated pro-inflammatory related gene expression following chronic hypoperfusion that was not affected by Nrf2 deficiency. CONCLUSIONS: The results demonstrate that the absence of Nrf2 exacerbates white matter pathology and microgliosis following cerebral hypoperfusion but does not affect behavioural impairment.
Assuntos
Encéfalo/patologia , Disfunção Cognitiva/metabolismo , Microglia/patologia , Fator 2 Relacionado a NF-E2/deficiência , Substância Branca/patologia , Animais , Isquemia Encefálica/etiologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Estenose das Carótidas/complicações , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Modelos Animais de Doenças , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Chronic cerebral hypoperfusion is a key mechanism associated with white matter disruption in cerebral vascular disease and dementia. In a mouse model relevant to studying cerebral vascular disease, we have previously shown that cerebral hypoperfusion disrupts axon-glial integrity and the distribution of key paranodal and internodal proteins in subcortical myelinated axons. This disruption of myelinated axons is accompanied by increased microglia and cognitive decline. The aim of the present study was to investigate whether hypoperfusion impairs the functional integrity of white matter, its relation with axon-glial integrity and microglial number, and whether by targeting microglia these effects can be improved. We show that in response to increasing durations of hypoperfusion, the conduction velocity of myelinated fibres in the corpus callosum is progressively reduced and that paranodal and internodal axon-glial integrity is disrupted. The number of microglial cells increases in response to hypoperfusion and correlates with disrupted paranodal and internodal integrity and reduced conduction velocities. Further minocycline, a proposed anti-inflammatory and microglia inhibitor, restores white matter function related to a reduction in the number of microglia. The study suggests that microglial activation contributes to the structural and functional alterations of myelinated axons induced by cerebral hypoperfusion and that dampening microglia numbers/proliferation should be further investigated as potential therapeutic benefit in cerebral vascular disease.
Assuntos
Anti-Inflamatórios/uso terapêutico , Estenose das Carótidas , Gliose/tratamento farmacológico , Gliose/etiologia , Microglia/efeitos dos fármacos , Minociclina/uso terapêutico , Substância Branca/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Arginase/genética , Arginase/metabolismo , Axônios/patologia , Estenose das Carótidas/complicações , Estenose das Carótidas/tratamento farmacológico , Estenose das Carótidas/patologia , Corpo Caloso/efeitos dos fármacos , Corpo Caloso/patologia , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Glicoproteína Associada a Mielina/metabolismo , Fibras Nervosas/efeitos dos fármacos , Fibras Nervosas/fisiologia , Substância Branca/patologia , Substância Branca/fisiologiaRESUMO
Cystinuria is suspected antenatally by a hyperechogenic fetal colonic content. We report the first prenatal case of autosomal dominant SLC7A9-related cystinuria associated with isolated hyperechogenic kidneys as the only prenatal sonographic sign.
RESUMO
BACKGROUND: OnabotulinumtoxinA (BTX-A) and anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (anti-CGRP mAbs) are approved drugs for chronic migraine (CM), a difficult-to-treat condition. Optimization of CM patient management by choosing the best options and determining appropriate time for switching or adding concomitant treatments are highly needed. OBJECTIVE: Evaluate clinical response to anti-CGRP mAbs in patients who switched from BTX-A due to ineffectiveness defined by different cut-offs and assess the retention rate, effectiveness, and safety of both drugs within the first 9 months of treatment. METHODS: A monocentric, cohort study, enrolling patients with CM, resistant to several preventive treatments, first treated with BTX-A and then with anti-CGRP mAbs with two observational phases of 9 months preceded by respective baseline. First, the retention rate and effectiveness of both treatments were measured in all patients. A second analysis assessed effectiveness in patients stratified according to <50 or <30% response rate to BTX-A. The absolute change from baseline in monthly headache days (MHDs), response rate, analgesic use, and persistence in medication overuse (MO) at 3, 6, and 9 months of treatment were recorded. Last observation carried forward (LOCF) analyses, including all patients and assuming no further changes after discontinuation, were performed for all outcomes. RESULTS: Of the 78 enrolled patients (80.8% female, and 89.7% with MO at baseline), 32 (41.0%) received erenumab, 32 (41.0%) galcanezumab, and 14 (18.0%) fremanezumab. Retention rate was 62.2 and 91.0% for BTX-A and 76.9 and 96.2%, for anti-CGRP mAbs at 3 and 9 months of treatment, respectively. At 9 months of treatment, 22.4% of BTX-A patients and 65.0% of anti-CGRP mAbs patients achieved a ≥50% response rate. Anti-CGRP mAbs reduced MHDs, AMN, and AMDs, and decreased the number of MO patients at 9 months. In patients stratified according to <50 or <30% response rate to BTX-A, response rate (≥50% response at 9 months) to anti-CGRP was 62.9 and 57.9%, respectively. LOCF analyses confirmed these findings. No serious adverse events (AEs) were recorded and only two patients discontinued treatment due to AEs. CONCLUSIONS: Difficult-to-treat CM patients who discontinued BTX-A and received anti-CGRP mAbs showed a substantial clinical improvement in migraine-related outcomes. Switching to an anti-CGRP mAb appears to be a viable option in patients with insufficient response after the first 2 cycles with BTX-A. The appropriate variables, cut-offs, and timing to define ineffectiveness and the best time to switch or combine therapies for difficult-to-treat CM need to be investigated further.
Assuntos
Toxinas Botulínicas Tipo A , Transtornos de Enxaqueca , Humanos , Feminino , Masculino , Peptídeo Relacionado com Gene de Calcitonina , Toxinas Botulínicas Tipo A/uso terapêutico , Estudos de Coortes , Transtornos de Enxaqueca/tratamento farmacológico , Cefaleia/tratamento farmacológicoRESUMO
Introduction: Ectodermal dysplasias (EDs) are a large group of rare and complex genetic disorders, affecting the development of two or more ectodermal structures. Hypohidrotic ED (HED) is the most frequent ED's phenotype and is characterized by hypodontia, hypotrichosis, and hypo/anhidrosis, leading to heat intolerance and hyperthermia. Case Presentation: We report a case of a 2-year-old girl with hair and teeth abnormalities associated with severe digestive symptoms responsible for failure to thrive. Genetic analysis by mass sequencing in parallel on a 4,867-gene panel was performed in duo (index case and her mother). The girl showed the presence of a new de novo c.100dupG variant in EDA responsible for HED associated with a diagnosis of food protein-induced enterocolitis syndrome (FPIES). Conclusion: We describe a patient with HED and a new EDA variant associated with a diagnosis of FPIES, both implicating increased intestinal permeability. The inclusion of FPIES as a possible digestive symptom of HED can be suggested, although it may occur only in a context of atopy.
RESUMO
In cases of fetal hydrops, searching for an etiology is essential to evaluate the fetal prognosis and propose the most appropriate management.
RESUMO
Background: Ciliopathies are rare diseases causing renal and extrarenal manifestations. Here, we report the case of a ciliopathy induced by a homozygous pathogenic variant in the TTC21B gene. Case Description: A 47-year-old patient started hemodialysis for chronic kidney disease (CKD) of unknown origin. She presented with early onset of hypertension, pre-eclampsia, myopia and cirrhosis. Renal biopsy showed mild interstitial fibrosis, tubular atrophy, and moderate arteriosclerosis while liver pathology demonstrates grade B biliary cirrhosis. Family history revealed several cases of early-onset severe hypertension and one case of end-stage renal disease (ESRD) needing kidney transplantation at twenty years of age. Clinical exome sequencing showed homozygosis for the pathogenic variant c.626C>T (p.Pro209Leu) in the TTC21B gene. The patient underwent combined liver-renal transplantation with an excellent renal and hepatic graft outcome. Conclusions: TTC21B gene mutations can lead heterogeneous to clinical manifestations and represent an underappreciated cause of ESRD. The paradigm in diagnosis of CKD of early onset and/or of unknown origin is changing and genetic counseling should be performed in all patients and families that meet those criteria. Renal or combined liver-renal transplantation represents the best option for patients suffering from those diseases in terms of prognosis and quality of life.
RESUMO
Although macrophages (MΦ) are known to play a central role in neuropathic pain, their contribution to cancer pain has not been established. Here we report that depletion of sciatic nerve resident MΦs (rMΦ) in mice attenuates mechanical/cold hypersensitivity and spontaneous pain evoked by intraplantar injection of melanoma or lung carcinoma cells. MΦ-colony stimulating factor (M-CSF) was upregulated in the sciatic nerve trunk and mediated cancer-evoked pain via rMΦ expansion, transient receptor potential ankyrin 1 (TRPA1) activation, and oxidative stress. Targeted deletion of Trpa1 revealed a key role for Schwann cell TRPA1 in sciatic nerve rMΦ expansion and pain-like behaviors. Depletion of rMΦs in a medial portion of the sciatic nerve prevented pain-like behaviors. Collectively, we identified a feed-forward pathway involving M-CSF, rMΦ, oxidative stress, and Schwann cell TRPA1 that operates throughout the nerve trunk to signal cancer-evoked pain. SIGNIFICANCE: Schwann cell TRPA1 sustains cancer pain through release of M-CSF and oxidative stress, which promote the expansion and the proalgesic actions of intraneural macrophages. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/12/3387/F1.large.jpg.
Assuntos
Dor do Câncer/patologia , Hiperalgesia/patologia , Macrófagos/imunologia , Melanoma Experimental/complicações , Nervos Periféricos/imunologia , Células de Schwann/imunologia , Canal de Cátion TRPA1/fisiologia , Animais , Dor do Câncer/etiologia , Dor do Câncer/metabolismo , Feminino , Hiperalgesia/etiologia , Hiperalgesia/metabolismo , Neoplasias Pulmonares/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
The nociceptin/orphanin FQ (N/OFQ)/N/OFQ receptor (NOP) system controls different biological functions including pain and cough reflex. Mixed NOP/opioid receptor agonists elicit similar effects to strong opioids but with reduced side effects. In this work, 31 peptides with the general sequence [Tyr/Dmt1,Xaa5]N/OFQ(1-13)-NH2 were synthesized and pharmacologically characterized for their action at human recombinant NOP/opioid receptors. The best results in terms of NOP versus mu opioid receptor potency were obtained by substituting both Tyr1 and Thr5 at the N-terminal portion of N/OFQ(1-13)-NH2 with the noncanonical amino acid Dmt. [Dmt1,5]N/OFQ(1-13)-NH2 has been identified as the most potent dual NOP/mu receptor peptide agonist so far described. Experimental data have been complemented by in silico studies to shed light on the molecular mechanisms by which the peptide binds the active form of the mu receptor. Finally, the compound exerted antitussive effects in an in vivo model of cough.
Assuntos
Peptídeos/química , Receptores Opioides mu/agonistas , Receptores Opioides/agonistas , Animais , Sítios de Ligação , Tosse/induzido quimicamente , Tosse/tratamento farmacológico , Modelos Animais de Doenças , Cobaias , Humanos , Interações Hidrofóbicas e Hidrofílicas , Masculino , Simulação de Dinâmica Molecular , Peptídeos/metabolismo , Peptídeos/uso terapêutico , Receptores Opioides/metabolismo , Receptores Opioides mu/genética , Receptores Opioides mu/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Relação Estrutura-Atividade , Receptor de NociceptinaRESUMO
OBJECTIVE: To find the genetic etiology of premature ovarian insufficiency (POI) in a patient with primary amenorrhea and hypergonadotropic hypogonadism. DESIGN: Case report. SETTING: University hospital. PATIENTS: A Belgian woman aged 32 years with POI at the age of 17, her parents, and her sister whose POI was diagnosed at age 29. INTERVENTIONS: Analysis of a panel of 31 genes implicated in POI (POIGP) using next-generation sequencing (NGS), Sanger sequencing, and in vitro functional study. MAIN OUTCOME MEASURES: Gene variants, family mutational segregation, and in vitro functional impact of the mutant proteins. RESULTS: The analysis of the gene panel using NGS identified the presence of two novel follicle-stimulating hormone receptor (FSHR) missense mutations at a compound heterozygous state in the affected patient: c.646 G>A, p.Gly216Arg, and c.1313C>T, p.Thr438Ile. Sanger sequencing showed the presence of each mutation at heterozygous state in the patient's parents and at heterozygous compound state in the affected sister. Both substituted amino acids (Gly216 and Thr438) were conserved in FSHR of several vertebrate species as well as in other glycoproteins receptors (TSHR and LHCGHR), suggesting a potentially important role in glycoprotein receptor function. An in vitro functional study showed similar results for both variants with more than 90% reduction of their cell surface expression and a 55% reduction of their FSH-induced cyclic adenosine 3':5' monophosphate (cAMP) production compared with the wild-type FSHR. CONCLUSIONS: The analysis of a gene panel of 31 genes implicated in POI allowed us to identify two novel partially inactivating mutations of FSHR that are likely responsible for the POI phenotype of the proband and of her affected sister.
RESUMO
PIK3CA-Related Overgrowth Spectrum (PROS) encompass a group of disorders which are mainly characterized by segmental overgrowth of several tissues as well as venous and lymphatic malformations. It is caused by heterozygous, usually somatic mosaic, pathogenic variants in the PIK3CA gene. However, some patients presenting mainly isolated megalencephaly or "Cowden-like" features have been described harboring constitutional mutations of PIK3CA. Here, we report the case of a woman whose pregnancy was interrupted at 34 weeks of gestation after the detection of the following ultrasound abnormalities: left diaphragmatic hernia with intrathoracic stomach, right deviation of heart, intrathoracic double bubble sign, macrocephaly and polyhydramnios. Fetal autopsy contributed to better characterize the phenotype, showing megalencephaly, left diaphragmatic eventration, facial dysmorphism (hypertelorism, abnormal hair line implantation) and duplication of distal portion of the small bowel. Clinical exome sequencing identified a de novo constitutional variant c.1030G>A p.(Val344Met) in PIK3CA. Although this mutation has been previously described (as constitutional variant) in pediatric patients, our case represents the first detailed description of the prenatal features found in association with a constitutional PIK3CA mutation. Moreover, this case contributes to delineate novel features (diaphragmatic eventration and duplication of the distal part of the small bowel) which could be identified in association with PROS.
Assuntos
Anormalidades Múltiplas/patologia , Feto Abortado/patologia , Classe I de Fosfatidilinositol 3-Quinases/genética , Transtornos do Crescimento/patologia , Mutação , Anormalidades Múltiplas/genética , Feto Abortado/metabolismo , Adulto , Feminino , Transtornos do Crescimento/genética , Humanos , FenótipoRESUMO
We present a case of a middle interhemispheric variant of antenatal discovery associated with a de novo missense variant (NM_007129.5: c.1109G>A p.(Cys370Tyr)) in the ZIC2 gene. Our case represents the first prenatal description of a ZIC2 missense mutation found in association with syntelencephaly.
RESUMO
BACKGROUND: The X-chromosome gene USP9X encodes a deubiquitylating enzyme that has been associated with neurodevelopmental disorders primarily in female subjects. USP9X escapes X inactivation, and in female subjects de novo heterozygous copy number loss or truncating mutations cause haploinsufficiency culminating in a recognizable syndrome with intellectual disability and signature brain and congenital abnormalities. In contrast, the involvement of USP9X in male neurodevelopmental disorders remains tentative. METHODS: We used clinically recommended guidelines to collect and interrogate the pathogenicity of 44 USP9X variants associated with neurodevelopmental disorders in males. Functional studies in patient-derived cell lines and mice were used to determine mechanisms of pathology. RESULTS: Twelve missense variants showed strong evidence of pathogenicity. We define a characteristic phenotype of the central nervous system (white matter disturbances, thin corpus callosum, and widened ventricles); global delay with significant alteration of speech, language, and behavior; hypotonia; joint hypermobility; visual system defects; and other common congenital and dysmorphic features. Comparison of in silico and phenotypical features align additional variants of unknown significance with likely pathogenicity. In support of partial loss-of-function mechanisms, using patient-derived cell lines, we show loss of only specific USP9X substrates that regulate neurodevelopmental signaling pathways and a united defect in transforming growth factor ß signaling. In addition, we find correlates of the male phenotype in Usp9x brain-specific knockout mice, and further resolve loss of hippocampal-dependent learning and memory. CONCLUSIONS: Our data demonstrate the involvement of USP9X variants in a distinctive neurodevelopmental and behavioral syndrome in male subjects and identify plausible mechanisms of pathogenesis centered on disrupted transforming growth factor ß signaling and hippocampal function.
Assuntos
Deficiências do Desenvolvimento , Deficiência Intelectual , Fator de Crescimento Transformador beta , Animais , Deficiências do Desenvolvimento/genética , Feminino , Haploinsuficiência , Humanos , Deficiência Intelectual/genética , Masculino , Camundongos , Fenótipo , Transdução de Sinais , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismoRESUMO
BACKGROUND: Statins represent a class of medications widely prescribed to efficiently treat dyslipidemia. These drugs inhibit 3-ßhydroxy 3ß-methylglutaryl Coenzyme A reductase (HMGR), the rate-limiting enzyme of mevalonate (MVA) pathway. Besides cholesterol, MVA pathway leads to the production of several other compounds, which are essential in the regulation of a plethora of biological activities, including in the central nervous system. For these reasons, statins are able to induce pleiotropic actions, and acquire increased interest as potential and novel modulators in brain processes, especially during pathological conditions. OBJECTIVE: The purpose of this review is to summarize and examine the current knowledge about pharmacokinetic and pharmacodynamic properties of statins in the brain. In addition, effects of statin on brain diseases are discussed providing the most up-to-date information. METHODS: Relevant scientific information was identified from PubMed database using the following keywords: statins and brain, central nervous system, neurological diseases, neurodegeneration, brain tumors, mood, stroke. RESULTS: 315 scientific articles were selected and analyzed for the writing of this review article. Several papers highlighted that statin treatment is effective in preventing or ameliorating the symptomatology of a number of brain pathologies. However, other studies failed to demonstrate a neuroprotective effect. CONCLUSION: Even though considerable research studies suggest pivotal functional outcomes induced by statin therapy, additional investigation is required to better determine the pharmacological effectiveness of statins in the brain, and support their clinical use in the management of different neuropathologies.
Assuntos
Encefalopatias/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Animais , Encéfalo/metabolismo , Encefalopatias/metabolismo , Encefalopatias/prevenção & controle , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Mouse models have shown that cerebral hypoperfusion causes white matter disruption and memory impairment relevant to the study of vascular cognitive impairment and dementia. The associated mechanisms include inflammation and oxidative stress are proposed to drive disruption of myelinated axons within hypoperfused white matter. The aim of this study was to determine if increased endogenous anti-oxidant and anti-inflammatory signalling in astrocytes was protective in a model of mild cerebral hypoperfusion. Transgenically altered mice overexpressing the transcription factor Nrf2 (GFAP-Nrf2) and wild type littermates were subjected to bilateral carotid artery stenosis or sham surgery. Behavioural alterations were assessed using the radial arm maze and tissue was collected for pathology and transcriptome analysis six weeks post-surgery. GFAP-Nrf2 mice showed less pronounced behavioural impairments compared to wild types following hypoperfusion, paralleled by reduced optic tract white matter disruption and astrogliosis. There was no effect of hypoperfusion on anti-oxidant gene alterations albeit the levels were increased in GFAP-Nrf2 mice. Instead, pro-inflammatory gene expression was determined to be significantly upregulated in the optic tract of hypoperfused wild type mice but differentially affected in GFAP-Nrf2 mice. In particular, complement components (C4 and C1q) were increased in wild type hypoperfused mice but expressed at levels similar to controls in hypoperfused GFAP-Nrf2 mice. This study provides evidence that overexpression of Nrf2 in astrocytes exerts beneficial effects through repression of inflammation and supports the potential use of Nrf2-activators in the amelioration of cerebrovascular-related inflammation and white matter degeneration.