RESUMEN
Telangiectases and arteriovenous malformations (AVMs) are the characteristic lesions of Hereditary Hemorrhagic Telangiectasia (HHT). Somatic second-hit loss-of-function variations in the HHT causative genes, ENG and ACVRL1, have been described in dermal telangiectasias. It is unclear if somatic second-hit mutations also cause the formation of AVMs and nasal telangiectasias in HHT. To investigate the genetic mechanism of AVM formation in HHT, we evaluated multiple affected tissues from fourteen individuals. DNA was extracted from fresh/frozen tissue of 15 nasal telangiectasia, 4 dermal telangiectasia, and 9 normal control tissue biopsies, from nine unrelated individuals with HHT. DNA from six formalin-fixed paraffin-embedded (FFPE) AVM tissues (brain, lung, liver, and gallbladder) from five individuals was evaluated. A 736 vascular malformation and cancer gene next-generation sequencing (NGS) panel was used to evaluate these tissues down to 1% somatic mosaicism. Somatic second-hit mutations were identified in three in four AVM biopsies (75%) or half of the FFPE (50%) samples, including the loss of heterozygosity in ENG in one brain AVM sample, in which the germline mutation occurred in a different allele than a nearby somatic mutation (both are loss-of-function mutations). Eight of nine (88.9%) patients in whom telangiectasia tissues were evaluated had a somatic mutation ranging from 0.68 to 1.96% in the same gene with the germline mutation. Six of fifteen (40%) nasal and two of four (50%) dermal telangiectasia had a detectable somatic second hit. Additional low-level somatic mutations in other genes were identified in several telangiectasias. This is the first report that nasal telangiectasias and solid organ AVMs in HHT are caused by very-low-level somatic biallelic second-hit mutations.
Asunto(s)
Malformaciones Arteriovenosas , Telangiectasia Hemorrágica Hereditaria , Humanos , Telangiectasia Hemorrágica Hereditaria/genética , Telangiectasia Hemorrágica Hereditaria/complicaciones , Telangiectasia Hemorrágica Hereditaria/patología , Femenino , Masculino , Persona de Mediana Edad , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/patología , Adulto , Endoglina/genética , Anciano , Mutación , Receptores de Activinas Tipo II/genética , Telangiectasia/genética , Telangiectasia/patología , Secuenciación de Nucleótidos de Alto RendimientoRESUMEN
Pulmonary arteriovenous malformations (PAVMs) are vascular anomalies resulting in abnormal connections between pulmonary arteries and veins. In 80% of cases, PAVMs are present from birth, but clinical manifestations are rarely seen in childhood. These congenital malformations are typically associated with Hereditary Hemorrhagic Telangiectasia (HHT), a rare disease that affects 1 in 5000/8000 individuals. HHT disease is frequently caused by mutations in genes involved in the TGF-ß pathway. However, approximately 15% of patients do not have a genetic diagnosis and, among the genetically diagnosed, more than 33% do not meet the Curaçao criteria. This makes clinical diagnosis even more challenging in the pediatric age group. Here, we introduce an 8-year-old patient bearing a severe phenotype of multiple diffuse PAVMs caused by an unknown mutation which ended in lung transplantation. Phenotypically, the case under study follows a molecular pattern which is HHT-like. Therefore, molecular- biological and cellular-functional analyses have been performed in primary endothelial cells (ECs) isolated from the explanted lung. The findings revealed a loss of functionality in lung endothelial tissue and a stimulation of endothelial-to-mesenchymal transition. Understanding the molecular basis of this transition could potentially offer new therapeutic strategies to delay lung transplantation in severe cases.
Asunto(s)
Células Endoteliales , Arteria Pulmonar , Venas Pulmonares , Telangiectasia Hemorrágica Hereditaria , Humanos , Telangiectasia Hemorrágica Hereditaria/genética , Telangiectasia Hemorrágica Hereditaria/patología , Niño , Arteria Pulmonar/anomalías , Arteria Pulmonar/patología , Venas Pulmonares/anomalías , Venas Pulmonares/patología , Células Endoteliales/metabolismo , Células Endoteliales/patología , Masculino , Mutación , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/patología , Malformaciones Arteriovenosas/metabolismo , Transición Epitelial-Mesenquimal/genética , Trasplante de Pulmón , Fístula Arteriovenosa/patología , Fístula Arteriovenosa/genética , Pulmón/patología , Pulmón/irrigación sanguínea , FemeninoRESUMEN
Arteriovenous malformations (AVMs) are congenital vascular anomalies with a poor prognosis. AVMs are considered intractable diseases, as there is no established approach for early diagnosis and treatment. Therefore, this study aimed to provide new evidence by analyzing microRNAs (miRNAs) associated with AVM. We present fundamental evidence for the early diagnosis and treatment of AVM by analyzing miRNAs in the endothelial cells of AVMs. This study performed sequencing and validation of miRNAs in endothelial cells from normal and AVM tissues. Five upregulated and two downregulated miRNAs were subsequently analyzed under hypoxia and vascular endothelial growth factor (VEGF) treatment by one-way analysis of variance (ANOVA). Under hypoxic conditions, miR-135b-5p was significantly upregulated in the AVM compared to that under normal conditions, corresponding to increased endothelial activity (p-value = 0.0238). VEGF treatment showed no significant increase in miR-135b-5p under normal conditions, however, a surge in AVM was observed. Under both hypoxia and VEGF treatment, comparison indicated a downregulation of miR-135b-5p in AVM. Therefore, miR-135b-5p was assumed to affect the pathophysiological process of AVM and might play a vital role as a potential biomarker of AVMs for application related to diagnosis and treatment.
Asunto(s)
Malformaciones Arteriovenosas , Biomarcadores , Células Endoteliales , MicroARNs , Factor A de Crecimiento Endotelial Vascular , MicroARNs/genética , MicroARNs/metabolismo , Humanos , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/metabolismo , Malformaciones Arteriovenosas/patología , Malformaciones Arteriovenosas/diagnóstico , Células Endoteliales/metabolismo , Células Endoteliales/patología , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Masculino , Femenino , Adulto , Hipoxia de la Célula/genéticaRESUMEN
INTRODUCTION: Brain arteriovenous malformations (bAVMs) present complex challenges in neurosurgery, requiring precise pre-surgical planning. In this context, 3D printing technology has emerged as a promising tool to aid in understanding bAVM morphology and enhance surgical outcomes, particularly in pediatric patients. This study aims to assess the feasibility and effectiveness of using 3D AVM models in pediatric bAVM surgery. METHODOLOGY: The study was conducted at Great Ormond Street Hospital, and cases were selected sequentially between October 2021 and February 2023. Eight pediatric bAVM cases with 3D models were compared to eight cases treated before the introduction of 3D printing models. The 3D modelling fidelity and clinical outcomes were assessed and compared between the two cohorts. RESULTS: The study demonstrated excellent fidelity between 3D models and actual operative anatomy, with a median difference of only 0.31 mm. There was no statistically significant difference in angiographic cure rates or complications between the 3D model group and the non-3D model group. Surgical time showed a non-significant increase in cases involving 3D models. Furthermore, the 3D model cohort included higher-grade bAVMs, indicating increased surgical confidence. CONCLUSION: This study demonstrates the feasibility and efficacy of utilizing 3D AVM models in pediatric bAVM surgery. The high fidelity between the models and actual operative anatomy suggests that 3D modelling can enhance pre-surgical planning and intraoperative guidance without significantly increasing surgical times or complications. Further research with larger cohorts is warranted to confirm and refine the application of 3D modelling in clinical practice.
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Malformaciones Arteriovenosas , Cuidados Intraoperatorios , Microcirugia , Seguridad del Paciente , Cuidados Preoperatorios , Impresión Tridimensional , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Malformaciones Arteriovenosas/clasificación , Malformaciones Arteriovenosas/patología , Malformaciones Arteriovenosas/cirugía , Estudios de Cohortes , Estudios de Factibilidad , Microcirugia/métodos , Cuidados Preoperatorios/métodos , Reproducibilidad de los Resultados , Resultado del Tratamiento , Cuidados Intraoperatorios/métodosRESUMEN
AIMS: BMP9 is a high affinity ligand of ALK1 and endoglin receptors that are mutated in the rare genetic vascular disorder hereditary hemorrhagic telangiectasia (HHT). We have previously shown that loss of Bmp9 in the 129/Ola genetic background leads to spontaneous liver fibrosis via capillarization of liver sinusoidal endothelial cells (LSEC) and kidney lesions. We aimed to decipher the molecular mechanisms downstream of BMP9 to better characterize its role in vascular homeostasis in different organs. METHODS AND RESULTS: For this, we performed an RNA-seq analysis on LSEC from adult WT and Bmp9-KO mice and identified over 2000 differentially expressed genes. Gene ontology analysis showed that Bmp9 deletion led to a decrease in BMP and Notch signalling, but also LSEC capillary identity while increasing their cell cycle. The gene ontology term 'glomerulus development' was also negatively enriched in Bmp9-KO mice vs. WT supporting a role for BMP9 in kidney vascularization. Through different imaging approaches (electron microscopy, immunostainings), we found that loss of Bmp9 led to vascular enlargement of the glomeruli capillaries associated with alteration of podocytes. Importantly, we also showed for the first time that the loss of Bmp9 led to spontaneous arteriovenous malformations (AVMs) in the liver, gastrointestinal tract, and uterus. CONCLUSION: Altogether, these results demonstrate that BMP9 plays an important role in vascular quiescence both locally in the liver by regulating endothelial capillary differentiation markers and cell cycle but also at distance in many organs via its presence in the circulation. It also reveals that loss of Bmp9 is sufficient to induce spontaneous AVMs, supporting a key role for BMP9 in the pathogenesis of HHT.
Asunto(s)
Malformaciones Arteriovenosas , Células Endoteliales , Factor 2 de Diferenciación de Crecimiento , Ratones Noqueados , Transducción de Señal , Animales , Factor 2 de Diferenciación de Crecimiento/metabolismo , Factor 2 de Diferenciación de Crecimiento/genética , Células Endoteliales/metabolismo , Células Endoteliales/patología , Malformaciones Arteriovenosas/metabolismo , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/patología , Modelos Animales de Enfermedad , Ratones de la Cepa 129 , Hígado/metabolismo , Hígado/patología , Hígado/irrigación sanguínea , Fenotipo , RNA-Seq , Receptores Notch/metabolismo , Receptores Notch/genética , MasculinoRESUMEN
BACKGROUND: Arteriovenous malformations (AVMs) are vascular anomalies characterized by abnormal shunting between arteries and veins. The progression of the AVMs and their hemodynamic and rheological relations are poorly studied, and there is a lack of a feasible experimental model. OBJECTIVE: To establish a model that cause only minimal micro-rheological alterations, compared to other AV models. METHODS: Sixteen female Sprague Dawley rats were randomly divided into control and AVM groups. End-to-end anastomoses were created between the saphenous veins and arteries to mimic AVM nidus. Hematological and hemorheological parameters were analyzed before surgery and on the 1st, 3rd, 5th, 7th, 9th, and 12th postoperative weeks. RESULTS: Compared to sham-operated Control group the AVM group did not show important alterations in hematological parameters nor in erythrocyte aggregation and deformability. However, slightly increased aggregation and moderately decreased deformability values were found, without significant differences. The changes normalized by the 12th postoperative week. CONCLUSIONS: The presented rat model of a small-caliber AVM created on saphenous vessels does not cause significant micro-rheological changes. The alterations found were most likely related to the acute phase reactions and not to the presence of a small-caliber shunt. The model seems to be suitable for further studies of AVM progression.
Asunto(s)
Malformaciones Arteriovenosas , Modelos Animales de Enfermedad , Ratas Sprague-Dawley , Animales , Ratas , Femenino , Malformaciones Arteriovenosas/patología , Vena Safena/patología , Hemorreología , Derivación Arteriovenosa Quirúrgica , Deformación Eritrocítica , Agregación EritrocitariaRESUMEN
We report the case of a newborn who was noted at birth to have an occipital scalp nodule presenting with a hair collar sign (HCS). The nodule had enlarged since birth. An MRI revealed a soft tissue mass on the occipital scalp without deep extension or cranial bone involvement. A biopsy of the nodule led to a diagnosis of arteriovenous malformation (AVM). A vascular malformation with HCS has not been reported before in North America. This case highlights the complexity of diagnosing a lesion with a hair collar sign.
Asunto(s)
Malformaciones Arteriovenosas , Cabello , Recién Nacido , Humanos , Cabello/patología , Cuero Cabelludo/patología , Malformaciones Arteriovenosas/diagnóstico por imagen , Malformaciones Arteriovenosas/patología , Cráneo , Imagen por Resonancia MagnéticaRESUMEN
BACKGROUND: Episodic growth due to microvascular proliferations (MVP) has been reported in congenital arteriovenous malformations (AVM), which are normally quiescent lesions composed of mature malformed vessels. Since AVM also may worsen under conditions of hormonal dysregulation, we hypothesized that hormonal influences may stimulate this process of vasoproliferative growth through potential interactions with hormone receptors (HR). METHODS: 13 Cases of AVM tissue with histologically documented vasoproliferative growth were analyzed quantitatively for the presence and tissue localization of estrogen receptor (ER), progesterone receptor (PGR), growth hormone receptor (GHR) and follicle-stimulating hormone receptor (FSHR) in relation to resident cells of interest (endothelial cells (EC), smooth muscle cells (SMC) and mast cells (MC)) by applying multiplex immunohistochemistry (IHC) staining. Expression patterns in lesions with MVP and mature vessels were quantified and compared. Available fresh frozen tissues of 3 AVM samples were used to confirm the presence of HR using Reverse-Transcriptase quantitative Polymerase Chain Reaction (RT-qPCR). RESULTS: All four HR studied were expressed in all cases within EC and SMC in areas of MVP and mature vessels, but not in normal skin tissue. ER, GHR, and FSHR showed more expression in EC of MVP and in SMC of mature vessels. RT-qPCR confirmed presence of all 4 HR in both areas. CONCLUSION: Expression of ER, PGR, GHR, and FSHR in vasoproliferative areas of congenital AVM could explain onset of sudden symptomatic growth, as has observed in a subpopulation of patients. These findings may have implications for eventual anti-hormonal targeted therapy in the lesions involved.
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Malformaciones Arteriovenosas , Malformaciones Vasculares , Humanos , Células Endoteliales/metabolismo , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/metabolismo , Malformaciones Arteriovenosas/patología , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , Hormonas/metabolismoRESUMEN
Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant vascular disorder characterized by small, dilated clustered vessels (telangiectasias) and by larger visceral arteriovenous malformations (AVMs), which directly connect the feeding arteries with the draining veins. These lesions are fragile, prone to rupture, and lead to recurrent epistaxis and/or internal hemorrhage among other complications. Germline heterozygous loss-of-function (LOF) mutations in Bone Morphogenic Protein 9 (BMP9) and BMP10 signaling pathway genes (endoglin-ENG, activin like kinase 1 ACVRL1 aka ALK1, and SMAD4) cause different subtypes of HHT (HHT1, HHT2 and HHT-juvenile polyposis (JP)) and have a worldwide combined incidence of about 1:5000. Expert clinicians and international scientists gathered in Cascais, Portugal from September 29th to October 2nd, 2022 to present the latest scientific research in the HHT field and novel treatment strategies for people living with HHT. During the largest HHT scientific conference yet, participants included 293 in person and 46 virtually. An impressive 209 abstracts were accepted to the meeting and 59 were selected for oral presentations. The remaining 150 abstracts were presented during judged poster sessions. This review article summarizes the basic and clinical abstracts selected as oral presentations with their new observations and discoveries as well as surrounding discussion and debate. Two discussion-based workshops were also held during the conference, each focusing on mechanisms and clinical perspectives in either AVM formation and progression or current and future therapies for HHT. Our hope is that this paper will represent the current progress and the remaining unanswered questions surrounding HHT, in order to serve as an update for those within the field and an invitation to those scientists and clinicians as yet outside of the field of HHT.
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Telangiectasia Hemorrágica Hereditaria , Humanos , Receptores de Activinas Tipo II/genética , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/patología , Proteínas Morfogenéticas Óseas/genética , Mutación , Transducción de Señal , Telangiectasia Hemorrágica Hereditaria/genética , Telangiectasia Hemorrágica Hereditaria/terapiaRESUMEN
Intraosseous arteriovenous malformations in jaws are rare congenital vascular abnormalities that the dentist may encounter. A vascular lesion or disease should be suspected when there is unexplained bleeding from the oral cavity. Diagnostic imaging is a valuable tool in diagnosing and localizing vascular lesions. An understanding of some of the salient clinical and radiographic features of arteriovenous malformations in jaws aids the clinician in correctly diagnosing this condition and avoids iatrogenic injuries, such as hasty tooth extraction, which may potentially cause severe bleeding and possibly death. The dentist should acknowledge their expertise/limitation, and know when the need for referral arises.
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Malformaciones Arteriovenosas , Embolización Terapéutica , Humanos , Adolescente , Malformaciones Arteriovenosas/diagnóstico por imagen , Malformaciones Arteriovenosas/patología , Mandíbula/diagnóstico por imagen , Mandíbula/irrigación sanguínea , Mandíbula/patologíaRESUMEN
In the course of military operations in modern war theaters, blast exposures are associated with the development of a variety of mental health disorders associated with a post-traumatic stress disorder-related features, including anxiety, impulsivity, insomnia, suicidality, depression, and cognitive decline. Several lines of evidence indicate that acute and chronic cerebral vascular alterations are involved in the development of these blast-induced neuropsychiatric changes. In the present study, we investigated late occurring neuropathological events associated with cerebrovascular alterations in a rat model of repetitive low-level blast-exposures (3 × 74.5 kPa). The observed events included hippocampal hypoperfusion associated with late-onset inflammation, vascular extracellular matrix degeneration, synaptic structural changes and neuronal loss. We also demonstrate that arteriovenous malformations in exposed animals are a direct consequence of blast-induced tissue tears. Overall, our results further identify the cerebral vasculature as a main target for blast-induced damage and support the urgent need to develop early therapeutic approaches for the prevention of blast-induced late-onset neurovascular degenerative processes.
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Malformaciones Arteriovenosas , Traumatismos por Explosión , Ratas , Masculino , Animales , Remodelación Vascular , Traumatismos por Explosión/complicaciones , Traumatismos por Explosión/patología , Encéfalo/patología , Inflamación/patología , Malformaciones Arteriovenosas/complicaciones , Malformaciones Arteriovenosas/patología , Modelos Animales de EnfermedadRESUMEN
BACKGROUND: Longitudinal mouse models of brain arteriovenous malformations (AVMs) are crucial for developing novel therapeutics and pathobiological mechanism discovery underlying brain AVM progression and rupture. The sustainability of existing mouse models is limited by ubiquitous Cre activation, which is associated with lethal hemorrhages resulting from AVM formation in visceral organs. To overcome this condition, we developed a novel experimental mouse model of hereditary hemorrhagic telangiectasia (HHT) with CreER-mediated specific, localized induction of brain AVMs. METHODS: Hydroxytamoxifen (4-OHT) was stereotactically delivered into the striatum, parietal cortex, or cerebellum of R26CreER; Alk12f/2f (Alk1-iKO) littermates. Mice were evaluated for vascular malformations with latex dye perfusion and 3D time-of-flight magnetic resonance angiography (MRA). Immunofluorescence and Prussian blue staining were performed for vascular lesion characterization. RESULTS: Our model produced two types of brain vascular malformations, including nidal AVMs (88%, 38/43) and arteriovenous fistulas (12%, 5/43), with an overall frequency of 73% (43/59). By performing stereotaxic injection of 4-OHT targeting different brain regions, Alk1-iKO mice developed vascular malformations in the striatum (73%, 22/30), in the parietal cortex (76%, 13/17), and in the cerebellum (67%, 8/12). Identical application of the stereotaxic injection protocol in reporter mice confirmed localized Cre activity near the injection site. The 4-week mortality was 3% (2/61). Seven mice were studied longitudinally for a mean (SD; range) duration of 7.2 (3; 2.3-9.5) months and demonstrated nidal stability on sequential MRA. The brain AVMs displayed microhemorrhages and diffuse immune cell invasion. CONCLUSIONS: We present the first HHT mouse model of brain AVMs that produces localized AVMs in the brain. The mouse lesions closely resemble the human lesions for complex nidal angioarchitecture, arteriovenous shunts, microhemorrhages, and inflammation. The model's longitudinal robustness is a powerful discovery resource to advance our pathomechanistic understanding of brain AVMs and identify novel therapeutic targets.
Asunto(s)
Fístula Arteriovenosa , Malformaciones Arteriovenosas , Telangiectasia Hemorrágica Hereditaria , Animales , Ratones , Humanos , Telangiectasia Hemorrágica Hereditaria/patología , Malformaciones Arteriovenosas/patología , Fístula Arteriovenosa/patología , Encéfalo/patologíaRESUMEN
BACKGROUND: Spinal vascular malformations (SVMs), including arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs), are a varied group of vascular lesions that can be subclassified according to localization, vascular structure, and hemodynamics. Early intervention is necessary to halt progression of disease and minimize irreversible dysfunction. We sought to characterize initial treatment success and recurrence rates following interventional treatment of various types of SVMs. METHODS: A systematic review and meta-analysis were performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. SVMs were categorized into 4 groups: dural AVFs, perimedullary AVFs, intramedullary AVMs, and extradural-intradural AVMs (e.g., epidural, paraspinal). Initial occlusion, recurrence, and complication rates were compared using random-effects analysis. RESULTS: There were 112 manuscripts included, with a total of 5626 patients with SVM. For treatment, 2735 patients underwent endovascular embolization, 2854 underwent surgical resection, and 37 underwent stereotactic radiosurgery. The initial treatment success and overall recurrence rates following surgical resection of all SVMs were 89.5% (95% CI: 80.5%-98.5%) and 2.3% (95% CI: 0.9%-3.7%), respectively. Those rates following endovascular embolization were 55.9% (95% CI: 30.3%-81.5%) and 27.7% (95% CI: 11.2%-44.2%), respectively. Higher rates of initial treatment success and lower rates of recurrence with surgery were observed in all subtypes compared to embolization. Overall complication rates were higher after embolization for each of the SVM categories. CONCLUSIONS: Surgical resection of SVMs provided higher rates of initial complete occlusion and lower rates of recurrence than endovascular techniques. Attaining technical success through obliteration must still be weighed against clinical impact and natural history of the specific vascular malformation.
Asunto(s)
Fístula Arteriovenosa , Malformaciones Arteriovenosas , Malformaciones Vasculares del Sistema Nervioso Central , Enfermedades del Tejido Conjuntivo , Embolización Terapéutica , Anomalías Musculoesqueléticas , Humanos , Médula Espinal/patología , Malformaciones Arteriovenosas/cirugía , Malformaciones Arteriovenosas/patología , Fístula Arteriovenosa/cirugía , Embolización Terapéutica/métodos , Malformaciones Vasculares del Sistema Nervioso Central/cirugía , Resultado del Tratamiento , Estudios RetrospectivosRESUMEN
Brain arteriovenous malformations (AVMs) may involve language areas but usually do not lead to aphasia. This study evaluated resting-state functional alterations and investigated the language reorganization mechanism in AVM patients. Thirty-nine patients with AVMs involving language areas and 32 age- and sex-matched healthy controls were prospectively enrolled. The AVM patients were categorized into three subgroups according to lesion location: the frontal (15 patients), temporal (14 patients), and parietal subgroups (10 patients). All subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI), and the amplitude of low-frequency fluctuation (ALFF) approach was applied to analyze rs-fMRI data. Language abilities were normal in all participants based on the Western Aphasia Battery. Compared with those of healthy subjects, ALFF values significantly increased (FDR corrected p < .01) in the anterior part of the right putamen in the frontal AVM subgroup, in the posterior part of the right inferior and middle temporal gyrus in the temporal AVM subgroup, and in the inferior lateral part of the left cerebellar hemisphere (lobule VIII) and the right inferior parietal lobule in the parietal AVM subgroup. Functional annotation using Neurosynth indicated that the ALFF t-map was only significantly positively associated with the language-related domain (FDR corrected p < .01). In patients with AVMs involving the language cortex, language network reorganization occurs to maintain normal language abilities. The brain areas recruited into the reorganized language network were located in the right cerebral and left cerebellar hemispheres, both of which are nondominant hemispheres. Differences in lesion location led to distinct reorganization patterns.
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Afasia , Malformaciones Arteriovenosas , Humanos , Encéfalo , Corteza Cerebral , Malformaciones Arteriovenosas/patología , LenguajeRESUMEN
Hereditary hemorrhagic telangiectasia (HHT) is a genetic vascular disorder characterized by the presence of arteriovenous malformation (AVM) in multiple organs. HHT is caused by mutations in genes encoding major constituents for transforming growth factor-ß (TGF-ß) family signaling: endoglin (ENG), activin receptor-like kinase 1 (ALK1), and SMAD4. The identity of physiological ligands for this ENG-ALK1 signaling pertinent to AVM formation has yet to be clearly determined. To investigate whether bone morphogenetic protein 9 (BMP9), BMP10, or both are physiological ligands of ENG-ALK1 signaling involved in arteriovenous network formation, we generated a novel Bmp10 conditional knockout mouse strain. We examined whether global Bmp10-inducible knockout (iKO) mice develop AVMs at neonatal and adult stages in comparison with control, Bmp9-KO, and Bmp9/10-double KO (dKO) mice. Bmp10-iKO and Bmp9/10-dKO mice showed AVMs in developing retina, postnatal brain, and adult wounded skin, while Bmp9-KO did not display any noticeable vascular defects. Bmp10 deficiency resulted in increased proliferation and size of endothelial cells in AVM vessels. The impaired neurovascular integrity in the brain and retina of Bmp10-iKO and Bmp9/10-dKO mice was detected. Bmp9/10-dKO mice exhibited the lethality and vascular malformation similar to Bmp10-iKO mice, but their phenotypes were more pronounced. Administration of BMP10 protein, but not BMP9 protein, prevented retinal AVM in Bmp9/10-dKO and endothelial-specific Eng-iKO mice. These data indicate that BMP10 is indispensable for the development of a proper arteriovenous network, whereas BMP9 has limited compensatory functions for the loss of BMP10. We suggest that BMP10 is the most relevant physiological ligand of the ENG-ALK1 signaling pathway pertinent to HHT pathogenesis.
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Malformaciones Arteriovenosas , Telangiectasia Hemorrágica Hereditaria , Animales , Ratones , Factor 2 de Diferenciación de Crecimiento/genética , Factor 2 de Diferenciación de Crecimiento/metabolismo , Células Endoteliales/metabolismo , Proteínas Morfogenéticas Óseas/genética , Telangiectasia Hemorrágica Hereditaria/metabolismo , Malformaciones Arteriovenosas/patología , Ratones Noqueados , Receptores de Activinas Tipo II/genética , Receptores de Activinas Tipo II/metabolismoRESUMEN
Vascular anomalies are common orbital lesions, while variations in previous nomenclature might hamper robust characterization of their clinicopathological and genetic features. We reviewed and reclassified 92 orbital vascular lesions by the modified International Society for the Study of Vascular Anomalies (ISSVA) classification with reappraising clinicopathological parameters of 4 main types of vascular malformations, including orbital venous malformation 1 (OVM1, cavernous venous malformation), OVM2 (varix), OVM3 (infiltrating venous malformation), and arteriovenous malformation (AVM). GJA4, BRAF, and KRAS mutations were assessed by Sanger sequencing. There were 90 cases of vascular malformations, consisting of 60 OVM1 (67%), 13 AVM (14%), 8 OVM2 (9%), 8 OVM3 (9%), and 1 lymphatic-venous malformation (1%). The prevailing OVM1, histologically characterized by well-delineated borders and a uniform cavernous growth pattern, predominantly occurred in intraconal space (57%, P = .019) with an older median age (49 years) and female predilection (73%). OVM2, OVM3, and AVM exhibited differences in the distributions of patients' ages and lesion locations. Sizes of lesions were significantly correlated with periorbital and intraconal/extraconal locations (P < .001). OVM1 had the lowest rate of residual and recurrent diseases (3%). GJA4 mutations were identified in 75% (44/59) of OVM1 but not in OVM2/3 and AVM. No BRAF or KRAS mutations were detected. In conclusion, the modified ISSVA scheme enables meaningful classification of orbital vascular malformations by highlighting the molecular correlation between the distinct clinicopathological features and specific GJA4 mutation in OVM1, which implies OVM1 as a unique variant of venous malformation genetically akin to cutaneous and hepatic counterparts.
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Malformaciones Arteriovenosas , Anomalías Linfáticas , Malformaciones Vasculares , Humanos , Femenino , Persona de Mediana Edad , Malformaciones Vasculares/genética , Malformaciones Vasculares/patología , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/patología , Venas/patología , MutaciónRESUMEN
Extracranial arteriovenous malformations (AVMs) are characterized by anomalous arterial-to-venous connections, aberrant angiogenesis, local inflammation and hypoxia, and disorganized histological architecture; however, the precise molecular perturbations leading to this phenotype remain elusive. We hypothesized that extracranial AVM tissue would demonstrate deregulation of the TGF-ß/BMP signaling pathway, which may serve as a potential target in the development of molecular-based therapies for AVMs. AVM tissue was harvested during resection from 10 patients with AVMs and compared to control tissue. Blood was collected from 14 AVM patients and 10 patients without AVMs as controls. Expression of TGF-ß/BMP pathway components was analyzed using RT-PCR, western blotting, and immunohistochemistry. Circulating levels of TGF-ß1 were analyzed by ELISA. Paired t tests were utilized to perform statistical analysis. The mRNA levels of TGF-ß1, ALK1, Endoglin (ENG), Smad6, Smad7, and Smad8 were significantly elevated in AVM tissue when compared to controls. Protein levels of TGF-ß1 and Smad3 were elevated in AVM tissue while protein levels of BMP-9, ALK1, Smad1, Smad6, and Smad8 were significantly decreased in AVMs. Immunohistochemistry demonstrated increased TGF-ß1 in the perivascular cells of AVMs compared to normal controls, and circulating levels of TGF-ß1 were significantly higher in AVM patients. Patients with AVMs demonstrate aberrant TGF-ß/BMP expression in AVM tissue and blood compared to controls. Targeting aberrantly expressed components of the TGF-ß/BMP pathway in extracranial AVMs may be a viable approach in the development of novel molecular therapies, and monitoring circulating TGF-ß1 levels may be a useful indicator of treatment success.
Asunto(s)
Malformaciones Arteriovenosas , Factor de Crecimiento Transformador beta1 , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/patología , Endoglina/genética , Factor 2 de Diferenciación de Crecimiento , Humanos , ARN Mensajero/genética , Factor de Crecimiento Transformador beta , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Brain arteriovenous malformations (AVMs) are a disorder wherein abnormal, enlarged blood vessels connect arteries directly to veins, without an intervening capillary bed. AVMs are one of the leading causes of hemorrhagic stroke in children and young adults. Most human sporadic brain AVMs are associated with genetic activating mutations in the KRAS gene. Our goal was to develop an in vitro model that would allow for simultaneous morphological and functional phenotypic data capture in real time during AVM disease progression. By generating human endothelial cells harboring a clinically relevant mutation found in most human patients (activating mutations within the small GTPase KRAS) and seeding them in a dynamic microfluidic cell culture system that enables vessel formation and perfusion, we demonstrate that vessels formed by KRAS4AG12V mutant endothelial cells (ECs) were significantly wider and more leaky than vascular beds formed by wild-type ECs, recapitulating key structural and functional hallmarks of human AVM pathogenesis. Immunofluorescence staining revealed a breakdown of adherens junctions in mutant KRAS vessels, leading to increased vascular permeability, a hallmark of hemorrhagic stroke. Finally, pharmacological blockade of MEK kinase activity, but not PI3K inhibition, improved endothelial barrier function (decreased permeability) without affecting vessel diameter. Collectively, our studies describe the creation of human KRAS-dependent AVM-like vessels in vitro in a self-assembling microvessel platform that is amenable to phenotypic observation and drug delivery.
Asunto(s)
Malformaciones Arteriovenosas , Accidente Cerebrovascular Hemorrágico , Malformaciones Arteriovenosas/genética , Malformaciones Arteriovenosas/metabolismo , Malformaciones Arteriovenosas/patología , Niño , Células Endoteliales/metabolismo , Humanos , Dispositivos Laboratorio en un Chip , Proteínas Proto-Oncogénicas p21(ras) , Adulto JovenRESUMEN
Acroangiodermatitis (AAD)[KL1] is a rare vasoproliferative disorder often involving the extremities that has been classified into two variants. Mali-type AAD is more common and associated with chronic venous stasis. Stewart-Bluefarb syndrome[KL2], the other variant, is associated with underlying arteriovenous abnormalities. Mali-type AAD is a relatively benign diagnosis but it may mimic more harmful etiologies such as Kaposi sarcoma both clinically and histologically. A 67-year-old woman with a history of varicose veins, deep vein thrombosis, stroke, and obesity presented to our outpatient clinic with verrucous red-brown papules and plaques on her right lower extremity worsening for three years. Biopsy was consistent with a diagnosis of Mali-type AAD. Providers should be aware of AAD and its variants to accurately differentiate it from more harmful entities.