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Loeys-Dietz syndrome (LDS) commonly presents with foot deformities, such as talipes equinovarus (TEV), also known as "clubfoot." Although much is known about the treatment of idiopathic TEV, very little is known about the treatment of TEV in LDS. Here, we summarize the clinical characteristics of patients with LDS and TEV and compare clinical and patient-reported outcomes of operative versus nonoperative treatment.We identified 47 patients with TEV from a cohort of 252 patients with LDS who presented to our academic tertiary care hospital from 2010 to 2016. A questionnaire, electronic health records, clinical photos and radiographs, and telephone calls were used to collect baseline, treatment, and outcome data. The validated disease-specific instrument was used to determine patient-reported foot/ankle functional limitations after treatment. Patients were categorized into nonoperative and operative groups, with the operative group subcategorized according to whether the posteromedial release was performed.Within our TEV cohort, bilateral TEV was present in 40 patients (85%). Thirty-seven patients underwent surgery (14 involving posteromedial release), and 10 were treated nonoperatively. The operative group had a higher incidence of posttreatment foot/ankle functional limitation (71%) than the nonoperative group (25%) ( P =0.04). The pain was the most common functional limitation (54%). The posteromedial release was associated with a higher incidence of developing hindfoot valgus compared with surgery not involving posteromedial release (43% vs. 8.7%, P =0.04) and compared with nonoperative treatment (43% vs. 0.0%, P =0.02).We found that patients with LDS have a high incidence of bilateral TEV. Operative treatment was associated with posttreatment foot/ankle functional limitations, and posteromedial release was associated with hindfoot valgus overcorrection deformity. These findings could have implications for the planning of surgery for TEV in LDS patients.Level III-retrospective comparative study.

Allergic diseases are a global health challenge. Individuals harboring loss-of-function variants in transforming growth factor–β receptor (TGFβR) genes have an increased prevalence of allergic disorders, including eosinophilic esophagitis. Allergic diseases typically localize to mucosal barriers, implicating epithelial dysfunction as a cardinal feature of allergic disease. Here, we describe an essential role for TGFβ in the control of tissue-specific immune homeostasis that provides mechanistic insight into these clinical associations. Mice expressing a TGFβR1 loss-of-function variant identified in atopic patients spontaneously develop disease that clinically, immunologically, histologically, and transcriptionally recapitulates eosinophilic esophagitis. In vivo and in vitro, TGFβR1 variant–expressing epithelial cells are hyperproliferative, fail to differentiate properly, and overexpress innate proinflammatory mediators, which persist in the absence of lymphocytes or external allergens. Together, our results support the concept that TGFβ plays a fundamental, nonredundant, epithelial cell–intrinsic role in controlling tissue-specific allergic inflammation that is independent of its role in adaptive immunity.

Loeys-Dietz syndrome (LDS) is characterized by a wide spectrum of musculoskeletal manifestations, including foot deformities. The spectrum of foot deformities in LDS has not been previously characterized. Our objective was to describe the incidence and characteristics of foot deformities in LDS. We retrospectively reviewed the demographic, clinical and imaging data for patients diagnosed with LDS who were seen at our Orthopedic surgery department from 2008 to 2021. We performed descriptive analyses and compared distributions of deformities by LDS genetic mutations. Of the 120 patients studied, most presented for evaluation of foot deformities ( N = 56, 47%) and scoliosis ( N = 45; 38%). Ninety-seven patients (81%) had at least one foot deformity, and 87% of these patients had bilateral foot deformities. The most common deformities were pes planovalgus (53%) and talipes equinovarus (34%). Of patients with foot deformities, 58% presented for evaluation of the feet. Of patients with pes planovalgus, only 17% presented for evaluation of the feet. Among patients with pes planovalgus, 2% underwent surgery and 16% used orthotics compared with 76% and 42%, respectively, for patients with talipes equinovarus. We found no association between deformities and genetic mutations. Bilateral foot deformities are highly prevalent in patients with LDS and are the most common reason for presentation to orthopedic surgeons. Although pes planovalgus is the most common deformity, it rarely prompted surgical treatment. Orthopedic surgeons treating LDS patients should be aware of the unique characteristics of foot deformities in LDS.

The objective of this study was to compare midterm outcomes of aortic valve-replacing root replacement (AVR) and aortic valve-sparing root replacement (AVS) operations in patients with Marfan syndrome.Patients who met strict Ghent diagnostic criteria for Marfan syndrome and who underwent either AVR or AVS between March 1, 2005 and December 31, 2010 were enrolled in a 3-year follow-up prospective, multicenter, international registry study; the study was subsequently amended to include 20-year follow-up. Enrollees were followed clinically and echocardiographically.Of the 316 patients enrolled, 77 underwent AVR and 239 underwent AVS; 214 gave reconsent for 20-year follow-up. The median clinical follow-up time for surviving patients was 64 months (interquartile range, 42-66 months). Survival rates for the AVR and AVS groups were similar at 88.2% ± 4.4% and 95.0% ± 1.5%, respectively (P = .1). Propensity score-adjusted competing risk modeling showed associations between AVS and higher cumulative incidences of major adverse valve-related events, valve-related morbidity, combined structural valve deterioration and nonstructural valve dysfunction, and aortic regurgitation ≥2+ (all P .01). No differences were found for reintervention (P = .7), bleeding (P = .2), embolism (P = .3), or valve-related mortality (P = .8).Five years postoperatively, major adverse valve-related events and valve-related morbidity were more frequent after AVS than after AVR procedures, primarily because of more frequent aortic valve dysfunction. No between-group differences were found in rates of survival, valve-related mortality, reintervention on the aortic valve, or bleeding. We plan to follow this homogenous cohort for 20 years after aortic root replacement.

Loeys-Dietz syndrome (LDS) is a rare autosomal-dominant connective tissue disorder caused by genetic mutations in the transforming growth factor-β (TGFβ) signaling pathway. In addition to vascular malformations, patients with LDS commonly present with bone and tendon abnormalities, including joint laxity. While TGFβ signaling dysregulation has been implicated in many of these clinical manifestations, the degree to which it influences the tendinopathy and tendon healing issues in LDS has not been determined.Wound healing after patellar tendon transection was compared between wild-type (WT) and Tgfbr2-mutant (LDS) mice (7 mice per group). In all mice, the right patellar tendon was transected at midsubstance, while the left was untouched to serve as a control. Mice were euthanized 6 weeks after surgery. Tendon specimens were harvested for histopathologic grading according to a previously validated scoring metric, and gene expression levels of Mmp2, Tgfb2, and other TGFβ-signaling genes were assayed. Between-group comparisons were made using 1-way analysis of variance with post hoc Tukey honestly significant difference testing.Expression levels of assayed genes were similar between LDS and WT tendons at baseline; however, at 6 weeks after patellar tendon transection, LDS tendons showed sustained elevations in Mmp2 and Tgfb2 compared with baseline values; these elevations were not seen in normal tendons undergoing the same treatments. Histologically, untreated LDS tendons had significantly greater cellularity and cell rounding compared with untreated WT tendons, and both WT and LDS tendons had significantly worse histologic scores after surgery.We present the first mechanistic insight into the effect of LDS on tendons and tendon healing. The morphologic differences between LDS and WT tendons at baseline may help explain the increased risk of tendon/ligament dysfunction in patients with LDS, and the differential healing response to injury in LDS may account for the delayed healing and weaker repair tissue.Level V.

PURPOSE In a large cohort of 373 pediatric patients with Marfan syndrome (MFS) with a severe cardiovascular phenotype, we explored the proportion of patients with MFS with a pathogenic FBN1 variant and analyzed whether the type/location of FBN1 variants was associated with specific clinical characteristics and response to treatment. Patients were recruited on the basis of the following criteria: aortic root z-score > 3, age 6 months to 25 years, no prior or planned surgery, and aortic root diameter < 5 cm. METHODS Targeted resequencing and deletion/duplication testing of FBN1 and related genes were performed. RESULTS We identified (likely) pathogenic FBN1 variants in 91% of patients. Ectopia lentis was more frequent in patients with dominant-negative (DN) variants (61%) than in those with haploinsufficient variants (27%). For DN FBN1 variants, the prevalence of ectopia lentis was highest in the N-terminal region (84%) and lowest in the C-terminal region (17%). The association with a more severe cardiovascular phenotype was not restricted to DN variants in the neonatal FBN1 region (exon 25-33) but was also seen in the variants in exons 26 to 49. No difference in the therapeutic response was detected between genotypes. CONCLUSION Important novel genotype-phenotype associations involving both cardiovascular and extra-cardiovascular manifestations were identified, and existing ones were confirmed. These findings have implications for prognostic counseling of families with MFS.

Vascular Ehlers-Danlos syndrome (vEDS) is an autosomal-dominant connective tissue disorder caused by heterozygous mutations in the COL3A1 gene, which encodes the pro-α 1 chain of collagen III. Loss of structural integrity of the extracellular matrix is believed to drive the signs and symptoms of this condition, including spontaneous arterial dissection and/or rupture, the major cause of mortality. We created 2 mouse models of vEDS that carry heterozygous mutations in Col3a1 that encode glycine substitutions analogous to those found in patients, and we showed that signaling abnormalities in the PLC/IP(3)/PKC/ERK pathway (phospholipase C/inositol 1,4,5-triphosphate/protein kinase C/extracellular signal–regulated kinase) are major mediators of vascular pathology. Treatment with pharmacologic inhibitors of ERK1/2 or PKCβ prevented death due to spontaneous aortic rupture. Additionally, we found that pregnancy- and puberty-associated accentuation of vascular risk, also seen in vEDS patients, was rescued by attenuation of oxytocin and androgen signaling, respectively. Taken together, our results provide evidence that targetable signaling abnormalities contribute to the pathogenesis of vEDS, highlighting unanticipated therapeutic opportunities.

PURPOSE: The growing size of public variant repositories prompted us to test the accuracy of pathogenicity prediction of DNA variants using population data alone. METHODS: Under the a priori assumption that the ratio of the prevalence of variants in healthy population vs that in affected populations form 2 distinct distributions (pathogenic and benign), we used a Bayesian method to assign probability to a variant belonging to either distribution. RESULTS: The approach, termed Bayesian prevalence ratio (BayPR), accurately parsed 300 of 313 expertly curated CFTR variants: 284 of 296 pathogenic/likely pathogenic variants in 1 distribution and 16 of 17 benign/likely benign variants in another. BayPR produced an area under the receiver operating characteristic curve of 0.99 for 103 functionally confirmed missense CFTR variants, which is equal to or exceeds 10 commonly used algorithms (area under the receiver operating characteristic curve range 0.54–0.99). Application of BayPR to expertly curated variants in 8 genes associated with 7 Mendelian conditions led to the assignment of a disease-causing probability of ≥80% to 1350 of 1374 (98.3%) pathogenic/likely pathogenic variants and of ≤20% to 22 of 23 (95.7%) benign/likely benign variants. CONCLUSION: Irrespective of the variant type or functional effect, the BayPR approach provides probabilities of pathogenicity for DNA variants responsible for Mendelian disorders using only the variant counts in affected and unaffected population samples.

Tremendous progress has been made in understanding the etiology, pathogenesis, and treatment of inherited vascular connective tissue disorders. While new insights regarding disease etiology and pathogenesis have informed patient counseling and care, there are numerous obstacles that need to be overcome in order to achieve the full promise of precision medicine. In this review, these issues will be discussed in the context of Marfan syndrome and Loeys-Dietz syndrome, with additional emphasis on the pioneering contributions made by Victor McKusick.

An asymptomatic 3-year-old with Loeys-Dietz Syndrome (LDS) followed for a small patent ductus arteriosus and dilated aorta was found to have a massive ductal aneurysm on routine surveillance cardiac magnetic resonance. The aneurysm was successfully resected. Serial advanced imaging tools are useful in surveillance, diagnosis, and management in patients with LDS.

Item does not contain fulltext Progressive dilatation of the thoracic aorta leads to thoracic aortic aneurysm (TAA), which is often asymptomatic but predisposes to lethal aortic dissections and ruptures. TAA is a common complication in patients with bicuspid aortic valve (BAV). Recently, rare loss-of-function SMAD6 variants were shown to contribute significantly to the genetic aetiology of BAV/TAA. Intriguingly, patients with craniosynostosis have also been reported to be explained molecularly by similar loss-of-function SMAD6 variants. While significantly reduced penetrance of craniosynostosis has been reported for the SMAD6 variants as such, near-complete penetrance is reached upon co-occurrence with a common BMP2 SNP risk allele. Here, we report on the results of a SMAD6-variant analysis in 473 unrelated non-syndromic TAA patients, of which the SMAD6-positive individuals were also studied for the presence of the BMP2 risk allele. Although only 14% of the TAA patients also presented BAV, all novel likely pathogenic SMAD6 variants (N = 7) were identified in BAV/TAA individuals, further establishing the role of SMAD6 variants to the aetiology of BAV/TAA and revealing limited contribution to TAA development in patients with a tricuspid aortic valve. Familial segregation studies confirmed reduced penetrance (82%) and variable clinical expressivity, with coarctation of the aorta being a common comorbidity. None of our six BMP2+/SMAD6+ patients presented with craniosynostosis. Hence, the proposed digenic model for craniosynostosis was not supported in the presented BAV/TAA cohort, suggesting that additional factors are at play. Finally, our data provide improved insights into the clinical spectrum of SMAD6-related BAV/TAA and has important implications for molecular diagnostics.

Loeys-Dietz syndrome (LDS) is a connective tissue disorder affecting multiple organ systems, including bone.We defined the bone phenotype and clinical predictors of low bone density and fracture risk in 77 patients with LDS type 1 to type 5.Patients with LDS had dual-energy x-ray absorptiometry (DXA) Z-scores significantly 0, and 50% of children and 9% of adults had Z-scores-2. Sixty percent of patients had ≥1 fracture, and 24% of patients with spinal x-rays scans showed spinal compression fractures. Lower body mass index, asthma, male sex and eosinophilic gastrointestinal disease were correlated with lower DXA Z-scores. The count of 5 LDS-associated skeletal features (scoliosis, pes planus, arachnodactyly, spondylolisthesis, and camptodactyly) in patients with LDS was correlated with DXA Z-score. Adults with ≥1 skeletal features had DXA Z-scores significantly 0, and children with2 features had DXA Z-score significantly-2. Bone turnover markers suggest accelerated bone resorption. Data from 5 patients treated with bisphosphonates suggest a beneficial effect.All LDS types are associated with reduced bone density and increased risk of fracture, which may be due to increased bone resorption. Clinical features can predict a subgroup of patients at highest risk of low bone density and fracture risk.

BackgroundMarfan syndrome (MFS) is a connective tissue disorder characterised by complex aortic pathology and a high prevalence of obstructive sleep apnoea (OSA). OSA produces intrathoracic transmural stresses that may accelerate aortic injury. The current study was designed to examine the associations between OSA risk and markers of aortic enlargement in MFS.MethodConsecutive patients with MFS were recruited at Johns Hopkins if they completed a STOP-BANG survey. Composite survey scores were categorised into those with low OSA risk (STOP-BANG ResultsOf the 89 participants studied, 28% had a high OSA risk and 32% had aortic grafts. Persons with high OSA risk had greater aortic root diameter (mm) (ß=4.13, SE=1.81, p=0.027) and aortic root dilatation (ß=2.80, SE=1.34, p=0.046) compared with those with low OSA risk . In addition, the odds of prior aortic root replacement was three times greater in those with high OSA risk compared with those with low OSA risk.ConclusionIn MFS, high OSA risk is associated with aortic enlargement and a threefold increased risk of having had prior aortic root replacement. These findings invite further exploration of the relationship between OSA and aortic disease in MFS, and studies to clarify whether targeted interventions for OSA might mitigate aortic disease progression in MFS.Registration numberIRB00157483.

Objective To test whether variants in ADRB1 and CYP2C9 genes identify subgroups of individuals with differential response to treatment for Marfan syndrome through analysis of data from a large, randomized trial. Study design In a subset of 250 white, non-Hispanic participants with Marfan syndrome in a prior randomized trial of atenolol vs losartan, the common variants rs1801252 and rs1801253 in ADRB1 and rs1799853 and rs1057910 in CYP2C9 were analyzed. The primary outcome was baseline-adjusted annual rate of change in the maximum aortic root diameter z-score over 3 years, assessed using mixed effects models. Results Among 122 atenolol-assigned participants, the 70 with rs1801253 CC genotype had greater rate of improvement in aortic root z-score compared with 52 participants with CG or GG genotypes (Time x Genotype interaction P =.005, mean annual z-score change +/- SE -0.20 +/- 0.03 vs -0.09 +/- 0.03). Among participants with the CC genotype in both treatment arms, those assigned to atenolol had greater rate of improvement compared with the 71 of the 121 assigned to losartan (interaction P =.002; -0.20 +/- 0.02 vs -0.07 +/- 0.02; P

Background: Bicuspid aortic valve (BAV) is the most prevalent congenital heart defect affecting 1% to 2% of the population. It is associated with ascending aorta dilatation. Valve morphology, aortic stenosis (AS), and aortic insufficiency (AI) have been proposed as potential risk factors; however, evaluating their role is difficult, as these factors are inherently related. The aim of this study was to determine whether BAV morphology and dysfunction are independent determinants for ascending aorta dilatation in pediatric patients. Methods: A multicenter, retrospective, cross-sectional study of pediatric BAV patients followed since 2004 was performed. Imaging data were assessed for BAV morphology, severity of AS and AI, history of coarctation, and aortic dimensions. Associations were determined using multivariable regression analysis. A subset of patients undergoing aortic interventions (balloon dilation or Ross) were assessed longitudinally. Results: Data were obtained from 2122 patients (68% male; median age 10.2 years). Fifty percent of patients had ascending aorta dilatation. Right and noncoronary cusp fusion, increasing AS and AI, and older age were independently associated with ascending aorta dilatation. A history of coarctation was associated with less ascending aorta dilatation. In patients with neither AS nor AI, 37% had ascending aorta dilatation (4% severe). No complications related to aortic dilatation occurred in this cohort. Aortic Z scores were determined, and a Z -score calculator was created for this population. Conclusions: In this large pediatric cohort of patients with BAV, valve morphology, AS, and AI are independently associated with ascending aorta dilatation, suggesting that hemodynamic factors influence aortopathy. However, even in BAVs with no AS or AI, there is significant ascending aorta dilatation independent of valve morphology. Interventions that led to changes in degree of AI and AS did not seem to influence change in aortic dimensions. The current BAV cohort can be used as a reference group for expected changes in aortic dimensions during childhood.

Loeys–Dietz syndrome (LDS) is a rare autosomal dominant connective tissue disorder, first described in 2005. It is characterized by widespread arterial tortuosity and aneurysmal disease in addition to a variety of skeletal (e.g., pectus excavatum or carinatum, scoliosis, camptodactyly, arachnodactyly), craniofacial (e.g., hypertelorism, bifid uvula, cleft palate, craniosynostosis), and cutaneous (e.g., easy bruising, translucent skin, dystrophic scarring) findings. The diagnosis is based on the presence of clinical findings and/or the identification of a causal variant in one of the known LDS genes. To date, mutations in six genes (TGFBR1, TGFBR2, SMAD2, SMAD3, TGFB2, and TGFB3) have been linked to the disease, all encoding key mediators of the canonical TGFβ signaling pathway. In LDS, dissections tend to occur at younger ages and smaller diameters when compared to other vascular connective tissue disorders. Administration of medications that mitigate biochemical abnormalities and reduce hemodynamic stress, cardiovascular imaging surveillance, and prophylactic surgical intervention represent pivotal management strategies. Malformations, dysfunction, or pain ensuing from the extra-cardiovascular anomalies are dealt with in a case-by-case manner, optimally based on the input of a multidisciplinary team of medical specialists.

A connective tissue disorder is any disease that impacts the structures between cells, typically impacting collagen or elastin protein production or function. Heritable disorders of connective tissue is a broad category, ranging from a description of nonspecific features (hypermobility, flat feet, scoliosis) seen somewhat commonly in the general population to genetic syndromes typically without vascular involvement (Stickler syndrome, Ehlers–Danlos syndrome) to syndromes predisposing to vascular tear or rupture (heritable thoracic aortic disease).

Objectives We sought to develop strategies for management of the aortic arch in patients with Loeys–Dietz syndrome (LDS) through a review of our clinical experience with these patients and a comparison with our experience in patients with Marfan syndrome (MFS). Methods We reviewed hospital and follow-up records of 79 patients with LDS and compared them with 256 patients with MFS who served as reference controls. Results In the LDS group, 16% of patients presented initially with acute aortic dissection (AAD) (67% type A, 33% type B) or developed AAD during follow-up, compared with 10% of patients with MFS (95% type A, 5% type B). There was no difference between patients with LDS or MFS in need for subsequent arch interventions after aortic root surgery (46% vs 50%, P = 1.0). Among the patients who never had AAD, the need for arch repair at initial root surgery was greater in patients with LDS (5% vs 0.4%, P = .04), as was the need for any subsequent aortic surgery (12% vs 1.3%, P = .0004). Late mortality in patients with LDS after arch repair was greater than in those patients who had no arch intervention (33% vs 6%, P = .007). Conclusions In the absence of dissection, patients with LDS have a greater rate of arch intervention after root surgery than patients with MFS. After a dissection, arch reintervention rates are similar in the 2 groups. Arch intervention portends greater late mortality in LDS.

Despite significant research efforts, clinical practice for arterial bypass surgery has been stagnant, and engineered grafts continue to face postimplantation challenges. Here, we describe the development and application of a durable small-diameter vascular graft with tailored regenerative capacity. We fabricated small-diameter vascular grafts by electrospinning fibrin tubes and poly(ε-caprolactone) fibrous sheaths, which improved suture retention strength and enabled long-term survival. Using surface topography in a hollow fibrin microfiber tube, we enable immediate, controlled perfusion and formation of a confluent endothelium within 3–4 days in vitro with human endothelial colony-forming cells, but a stable endothelium is noticeable at 4 weeks in vivo. Implantation of acellular or endothelialized fibrin grafts with an external ultrathin poly(ε-caprolactone) sheath as an interposition graft in the abdominal aorta of a severe combined immunodeficient Beige mouse model supports normal blood flow and vessel patency for 24 weeks. Mechanical properties of the implanted grafts closely approximate the native abdominal aorta properties after just 1 week in vivo. Fibrin mediated cellular remodeling, stable tunica intima and media formation, and abundant matrix deposition with organized collagen layers and wavy elastin lamellae. Endothelialized grafts evidenced controlled healthy remodeling with delayed and reduced macrophage infiltration alongside neo vasa vasorum-like structure formation, reduced calcification, and accelerated tunica media formation. Our studies establish a small-diameter graft that is fabricated in less than 1 week, mediates neotissue formation and incorporation into the native tissue, and matches the native vessel size and mechanical properties, overcoming main challenges in arterial bypass surgery.

BACKGROUND Thoracic aortic aneurysms progressively enlarge and predispose to acute aortic dissections. Up to 25% of individuals with thoracic aortic disease harbor an underlying Mendelian pathogenic variant. An evidence-based strategy for selection of genes to test in hereditary thoracic aortic aneurysm and dissection (HTAAD) helps inform family screening and intervention to prevent life-threatening thoracic aortic events. OBJECTIVES The purpose of this study was to accurately identify genes that predispose to HTAAD using the Clinical Genome Resource (ClinGen) framework. METHODS We applied the semiquantitative ClinGen framework to assess presumed gene-disease relationships between 53 candidate genes and HTAAD. Genes were classified as causative for HTAAD if they were associated with isolated thoracic aortic disease and were clinically actionable, triggering routine aortic surveillance, intervention, and family cascade screening, All gene-disease assertions were evaluated by a pre-defined curator-expert pair and subsequently discussed with an expert panel. RESULTS Genes were classified based on the strength of association with HTAAD into 5 categories: definitive (n = 9), strong (n = 2), moderate (n = 4), limited (n = 15), and no reported evidence (n = 23). They were further categorized by severity of associated aortic disease and risk of progression. Eleven genes in the definitive and strong groups were designated as "HTAAD genes" (category A). Eight genes were classified as unlikely to be progressive (category B) and 4 as low risk (category C). The remaining genes were recent genes with an uncertain classification or genes with no evidence of association with HTAAD. CONCLUSIONS The ClinGen framework is useful to semiquantitatively assess the strength of gene-disease relationships for HTAAD. Gene categories resulting from the curation may inform clinical laboratories in the development, interpretation, and subsequent clinical implications of genetic testing for patients with aortic disease, (C) 2018 the American College of Cardiology Foundation, Published by Elsevier. Alt rights reserved.

Aim Thoracic aortic aneurysms are a life-threatening condition often diagnosed too late. To discover novel robust biomarkers, we aimed to better understand the molecular mechanisms underlying aneurysm formation.Methods and results In Fibulin-4(R/R) mice, the extracellular matrix protein Fibulin-4 is 4-fold reduced, resulting in progressive ascending aneurysm formation and early death around 3 months of age. We performed proteomics and genomics studies on Fibulin-4(R/R) mouse aortas. Intriguingly, we observed alterations in mitochondrial protein composition in Fibulin-4(R/R) aortas. Consistently, functional studies in Fibulin-4(R/R) vascular smooth muscle cells (VSMCs) revealed lower oxygen consumption rates, but increased acidification rates. Yet, mitochondria in Fibulin-4(R/R) VSMCs showed no aberrant cytoplasmic localization. We found similar reduced mitochondrial respiration in Tgfbr-1(M318R/+) VSMCs, a mouse model for Loeys-Dietz syndrome (LDS). Interestingly, also human fibroblasts from Marfan (FBN1) and LDS (TGFBR2 and SMAD3) patients showed lower oxygen consumption. While individual mitochondrial Complexes I-V activities were unaltered in Fibulin-4(R/R) heart and muscle, these tissues showed similar decreased oxygen consumption. Furthermore, aortas of aneurysmal Fibulin-4(R/R) mice displayed increased reactive oxygen species (ROS) levels. Consistent with these findings, gene expression analyses revealed dysregulation of metabolic pathways. Accordingly, blood ketone levels of Fibulin-4(R/R) mice were reduced and liver fatty acids were decreased, while liver glycogen was increased, indicating dysregulated metabolism at the organismal level. As predicted by gene expression analysis, the activity of PGC1 alpha, a key regulator between mitochondrial function and organismal metabolism, was downregulated in Fibulin-4(R/R) VSMCs. Increased TGF beta reduced PGC1 alpha levels, indicating involvement of TGF beta signalling in PGC1 alpha regulation. Activation of PGC1 alpha restored the decreased oxygen consumption in Fibulin-4(R/R) VSMCs and improved their reduced growth potential, emphasizing the importance of this key regulator.Conclusion Our data indicate altered mitochondrial function and metabolic dysregulation, leading to increased ROS levels and altered energy production, as a novel mechanism, which may contribute to thoracic aortic aneurysm formation.

Background: Moderate hyperhomocysteinemia is an attractive target for intervention because it is present in 5-7% of the population and can be reversed by diet. This approach presupposes that hyperhomocysteinemia is directly involved in the disease process. Epidemiologic studies have indicated that moderately elevated homocysteine may contribute to thoracic aortic aneurysm (TAA) dilatation and dissection in humans. In vitro, elevated homocysteine disrupts the structure and function of extracellular matrix components, suggesting that moderate hyperhomocysteinemia may contribute to the development and/or progression of TAA.Objective: We investigated moderately elevated homocysteine in the development and progression of TAA in a mouse model of Marfan syndrome (MFS) and in isogenic wild-type mice. The MFS mouse is a well-described model of a systemic connective tissue disorder characterized by thoracic aortic dilatation, dissection, and rupture. We used this model as a sensitized indicator system to examine the impact of homocysteine on the progression of TAA.Methods: Murine fibrillin 1 gene (Fbn1)C1039G/+ MFS and C57BL/6J wild-type mice were fed a cobalamin-restricted diet to induce moderate hyperhomocysteinemia from weaning until the age of 32 wk. Homocysteine and methylmalonic acid were measured and aortic root diameter assessed with the use of echocardiography in mice aged 3, 7, 15, and 32 wk.Results: Cobalamin-restricted mice exhibited significantly higher homocysteine (P < 0.0001) and methylmalonic acid (P < 0.0001) in the blood. For both strains, no significant difference in thoracic aortic diameter was observed in mice on the cobalamin-restricted diet compared with those on the control diet.Conclusions:Fbn1C1039G/+ mice are a well-characterized model of progressive aortic root dilation. Hyperhomocysteinemia in the physiologic range did not induce abnormal aortic growth in wild-type mice and did not accelerate or otherwise influence aortic root growth and pathologic progression in mice with an underlying predisposition for aortic dilatation.

In pediatric patients with connective tissue disorders (CTDs), early cardiac presentation often involves severe mitral regurgitation (MR) associated with severe bileaflet prolapse and, less frequently, aortic root enlargement. We adopted a simplified repair to address MR and prevent systolic anterior motion (SAM) in this unique group of patients.Retrospective review of clinical and echocardiographic data of all pediatric patients (age 18 years) with CTD and MR undergoing simplified repair at 3 institutions (2000-2014).Eighteen children who underwent surgery for severe MR and bileaflet prolapse were identified. All were treated with ring annuloplasty and Alfieri edge-to-edge repair. Median age and weight were 8.2 years (range, 0.4-17.2 years) and 24.9 kg (5.6-63.3 kg), respectively. Median left ventricular end diastolic dimension median z score was 4.9 (2.1-11.9). One patient died (5.6%), and there were no other major complications. Among survivors, 94.4% had mild regurgitation or less, with no stenosis or SAM at median clinical follow-up of 2.4 years (range, 0-13.9 years). Median left ventricular end-diastolic dimension z score regressed to 1.3 (-0.5 to 4.3).In pediatric patients with CTD and severe MR, a simplified approach is associated with intermediate-term competence, absence of SAM or significant stenosis, and regression of left ventricular enlargement.

Contains fulltext : 175552.pdf (Publisher’s version ) (Open Access) PURPOSE: Thoracic aortic aneurysm and dissection (TAAD) is typically inherited in an autosomal dominant manner, but rare X-linked families have been described. So far, the only known X-linked gene is FLNA, which is associated with the periventricular nodular heterotopia type of Ehlers-Danlos syndrome. However, mutations in this gene explain only a small number of X-linked TAAD families. METHODS: We performed targeted resequencing of 368 candidate genes in a cohort of 11 molecularly unexplained Marfan probands. Subsequently, Sanger sequencing of BGN in 360 male and 155 female molecularly unexplained TAAD probands was performed. RESULTS: We found five individuals with loss-of-function mutations in BGN encoding the small leucine-rich proteoglycan biglycan. The clinical phenotype is characterized by early-onset aortic aneurysm and dissection. Other recurrent findings include hypertelorism, pectus deformity, joint hypermobility, contractures, and mild skeletal dysplasia. Fluorescent staining revealed an increase in TGF-beta signaling, evidenced by an increase in nuclear pSMAD2 in the aortic wall. Our results are in line with those of prior reports demonstrating that Bgn-deficient male BALB/cA mice die from aortic rupture. CONCLUSION: In conclusion, BGN gene defects in humans cause an X-linked syndromic form of severe TAAD that is associated with preservation of elastic fibers and increased TGF-beta signaling.Genet Med 19 4, 386-395.

Genetic etiologies of chronic mucocutaneous candidiasis (CMC) disrupt human IL-17A/F-dependent immunity at mucosal surfaces, whereas those of connective tissue disorders (CTDs) often impair the TGF-β-dependent homeostasis of connective tissues. The signaling pathways involved are incompletely understood. We report a three-generation family with an autosomal dominant (AD) combination of CMC and a previously undescribed form of CTD that clinically overlaps with Ehlers-Danlos syndrome (EDS). The patients are heterozygous for a private splice-site variant of MAPK8, the gene encoding c-Jun N-terminal kinase 1 (JNK1), a component of the MAPK signaling pathway. This variant is loss-of-expression and loss-of-function in the patients' fibroblasts, which display AD JNK1 deficiency by haploinsufficiency. These cells have impaired, but not abolished, responses to IL-17A and IL-17F. Moreover, the development of the patients' TH17 cells was impaired ex vivo and in vitro, probably due to the involvement of JNK1 in the TGF-β-responsive pathway and further accounting for the patients' CMC. Consistently, the patients' fibroblasts displayed impaired JNK1- and c-Jun/ATF-2-dependent induction of key extracellular matrix (ECM) components and regulators, but not of EDS-causing gene products, in response to TGF-β. Furthermore, they displayed a transcriptional pattern in response to TGF-β different from that of fibroblasts from patients with Loeys-Dietz syndrome caused by mutations of TGFBR2 or SMAD3, further accounting for the patients' complex and unusual CTD phenotype. This experiment of nature indicates that the integrity of the human JNK1-dependent MAPK signaling pathway is essential for IL-17A- and IL-17F-dependent mucocutaneous immunity to Candida and for the TGF-β-dependent homeostasis of connective tissues.

Fibrosis is a common pathologic outcome of chronic disease resulting in the replacement of normal tissue parenchyma with a collagen-rich extracellular matrix produced by myofibroblasts. Although the progenitor cell types and cellular programs giving rise to myofibroblasts through mesenchymal transition can vary between tissues and diseases, their contribution to fibrosis initiation, maintenance, and progression is thought to be pervasive. Here we showed that the ability of transforming growth factor-β (TGFβ) to efficiently induce myofibroblast differentiation of cultured epithelial cells, endothelial cells, or quiescent fibroblasts is dependent upon the induced expression and activity of dimeric calpains, a family of non-lysosomal cysteine proteases that regulate a variety of cellular events through post-translational modification of diverse substrates. siRNA-based gene silencing demonstrated that TGFβ-induced mesenchymal transition of a murine breast epithelial cell line was dependent upon induction of expression of calpain 9 (CAPN9), an isoform previously thought to be restricted to the gastrointestinal tract. Mice lacking functional CAPN9 due to biallelic targeting of Capn9 were viable and fertile, but showed overt protection from bleomycin-induced lung fibrosis, carbon tetrachloride-induced liver fibrosis, and angiotensin II-induced cardiac fibrosis and dysfunction. A predicted loss-of-function allele of CAPN9 is common in Southeast Asia, with the frequency of homozygosity matching the prediction of Hardy-Weinberg equilibrium; together with the highly spatially-restricted pattern of CAPN9 expression under physiologic circumstances and the heartiness of the murine knockout, these data provide a strong signature for tolerance of therapeutic strategies for fibrosis aimed at CAPN9 antagonism.

In systemic sclerosis (SSc), previously healthy adults develop an inflammatory prodrome with subsequent progressive fibrosis of the skin and viscera. SSc has a weak signature for genetic contribution, and there are few pathogenic insights or targeted treatments for this condition. Here, chromatin accessibility and transcriptome profiling coupled with targeted epigenetic editing revealed constitutive activation of a previously unannotated transforming growth factor-β2 (TGFB2) enhancer maintained through epigenetic memory in SSc. The resulting autocrine TGFβ2 signaling enforced a profibrotic synthetic state in ex vivo fibroblasts from patients with SSc. Inhibition of NF-κB or BRD4 achieved sustained inhibition of TGFB2 enhancer activity, mitigated profibrotic gene expression, and reversed dermal fibrosis in patient skin explants. These findings suggest a potential epigenetic mechanism of fibrosis in SSc and inform a regulatory mechanism of TGFB2, a major profibrotic cytokine.

Vascular Ehlers-Danlos Syndrome (vEDS) is an autosomal-dominant connective tissue disorder caused by heterozygous mutations in the COL3A1 gene[1][1]. Currently, loss of structural integrity of the extracellular matrix is believed to drive the signs and symptoms of this condition, including

On average, Peruvian individuals are among the shortest in the world1. Here we show that Native American ancestry is associated with reduced height in an ethnically diverse group of Peruvian individuals, and identify a population-specific, missense variant in the FBN1 gene (E1297G) that is significantly associated with lower height. Each copy of the minor allele (frequency of 4.7%) reduces height by 2.2 cm (4.4 cm in homozygous individuals). To our knowledge, this is the largest effect size known for a common height-associated variant. FBN1 encodes the extracellular matrix protein fibrillin 1, which is a major structural component of microfibrils. We observed less densely packed fibrillin-1-rich microfibrils with irregular edges in the skin of individuals who were homozygous for G1297 compared with individuals who were homozygous for E1297. Moreover, we show that the E1297G locus is under positive selection in non-African populations, and that the E1297 variant shows subtle evidence of positive selection specifically within the Peruvian population. This variant is also significantly more frequent in coastal Peruvian populations than in populations from the Andes or the Amazon, which suggests that short stature might be the result of adaptation to factors that are associated with the coastal environment in Peru. In an ethnically diverse group of Peruvian individuals, the population-specific, missense variant in FBN1 (E1297G) is associated with lower height and shows evidence of positive selection within the Peruvian population.

Objective: Bicuspid aortic valve is a common risk factor for thoracic aortic aneurysm and dissection. Guidelines for elective ascending aortic intervention (AAI) in bicuspid aortic valve are derived from limited evidence, and the extent of practice variation due to patient and provider characteristics is unknown. Using data from 2 large cardiovascular registries, we investigated factors that influence decisions for AAI. Methods: All bicuspid aortic valve cases with known aortic diameters and surgical status were included. We used multivariable logistic regression to profile predictors of isolated aortic valve replacement (AVR) or AVR+AAI, stratified by patient characteristics, surgical indications, and institution. Results: We studied 2861 subjects at 18 institutions from 1996 to 2015. The median aortic diameter of patients who underwent AVR+AAI varied widely across institutions (39-52 mm). Aortic diameters were

Background: In patients with ascending aortic aneurysms (AscAA), biomechanical differences are seen among patients with congenital bicuspid aortic valves (BAV), Marfan syndrome (MFS), and tricuspid aortic valves (TAV). We examined the hemodynamic profiles and ultrastructures of aneurysmal specimens, focusing on vascular remodelling to better understand AscAA pathogenesis. Methods: A total of 795 patients with BAV (43.97 +/- 0.51 years; 93.2% male), 69 with MFS (34.43 +/- 1.44 years; 86.2% male), and 90 with TAV (67.27 +/- 0.58 years; 60% male) were enrolled, primarily upon admission with AscAA. The biomechanical properties of the aortic root were assessed and intraoperative specimens were analyzed by light-microscopy and two-photon autofluorescence microscopy. Results: Patientswith BAV had significantly greater distension of the aortic root, irrespective of age or aneurysmal widening (R-2= 0.543, p < 0.05). This was associated with significantly increase in the size of the tunica media. Patients with MFS displayed significant stiffness in the sinuses that worsened with age (R-2 = 0.752, p < 0.001), similar to patients with TAV (R-2= 0.626, p < 0.05). Patients with MFS showed significant root elasticity with aneurysmal growth (R-2 = 0.596, p < 0.05) and increased medial degeneration. Patients with TAV maintained biomechanical properties, apart from aneurysmal dimensions and high levels of inflammation. Conclusions: Among patientswith AscAA, those with BAVmaintain tissue elasticity in the aortic root, regardless of age. Patients with MFS demonstrate increased sinus stiffness with medial degeneration, both during aging and with aneurysmal growth. Patients with TAV and AscAA present with increased inflammation. (c) 2018 Published by Elsevier B.V.

Bicuspid aortic valve (BAV) is a common congenital heart defect (population incidence, 1-2%) that frequently presents with ascending aortic aneurysm (AscAA)4. BAV/AscAA shows autosomal dominant inheritance with incomplete penetrance and male predominance. Causative gene mutations (for example, NOTCH1, SMAD6) are known for ≤1% of nonsyndromic BAV cases with and without AscAA, impeding mechanistic insight and development of therapeutic strategies. Here, we report the identification of variants in ROBO4 (which encodes a factor known to contribute to endothelial performance) that segregate with disease in two families. Targeted sequencing of ROBO4 showed enrichment for rare variants in BAV/AscAA probands compared with controls. Targeted silencing of ROBO4 or mutant ROBO4 expression in endothelial cell lines results in impaired barrier function and a synthetic repertoire suggestive of endothelial-to-mesenchymal transition. This is consistent with BAV/AscAA-associated findings in patients and in animal models deficient for ROBO4. These data identify a novel endothelial etiology for this common human disease phenotype. Bicuspid aortic valve (BAV) is a common congenital heart defect (population incidence, 1-2%) that frequently presents with ascending aortic aneurysm (AscAA)4. BAV/AscAA shows autosomal dominant inheritance with incomplete penetrance and male predominance. Causative gene mutations (for example, NOTCH1, SMAD6) are known for ≤1% of nonsyndromic BAV cases with and without AscAA, impeding mechanistic insight and development of therapeutic strategies. Here, we report the identification of variants in ROBO4 (which encodes a factor known to contribute to endothelial performance) that segregate with disease in two families. Targeted sequencing of ROBO4 showed enrichment for rare variants in BAV/AscAA probands compared with controls. Targeted silencing of ROBO4 or mutant ROBO4 expression in endothelial cell lines results in impaired barrier function and a synthetic repertoire suggestive of endothelial-to-mesenchymal transition. This is consistent with BAV/AscAA-associated findings in patients and in animal models deficient for ROBO4. These data identify a novel endothelial etiology for this common human disease phenotype.

In the published version of this paper the author Neus Baena's name was incorrectly given as Neus Baena Diez. This has now been corrected in both the HTML and PDF versions of the paper.

Background Aortic dissection (AoD) is a serious complication of thoracic aortic aneurysm (TAA). Relative risk for AoD in relation to TAA etiology, incidence, and pattern after prophylactic TAA surgery are poorly understood. Objectives This study sought to determine the incidence, pattern, and relative risk for AoD among patients with genetically associated TAA. Methods The population included adult GenTAC participants without AoD at baseline. Standardized core laboratory tests classified TAA etiology and measured aortic size. Follow-up was performed for AoD. Results Bicuspid aortic valve (BAV) (39%) and Marfan syndrome (MFS) (22%) were the leading diagnoses in the studied GenTAC participants (n = 1,991). AoD occurred in 1.6% over 3.6 ± 2.0 years; 61% of AoD occurred in patients with MFS. Cumulative AoD incidence was 6-fold higher among patients with MFS (4.5%) versus others (0.7%; p Conclusions Among patients with genetically associated TAA, MFS augments risk for AoD even after TAA grafting. Although increased aortic size is a risk factor for subsequent AoD, events typically occur below established thresholds for prophylactic TAA repair.

Prophylactic aortic root replacement improves survival in patients with Marfan syndrome with aortic root aneurysms, but the optimal procedure remains undefined.Adult patients with Marfan syndrome who had Bentall or aortic valve-sparing root replacement (VSRR) procedures between 1997 and 2013 were identified. Comprehensive follow-up information was obtained from hospital charts and telephone contact.One hundred sixty-five adult patients with Marfan syndrome (aged20 years) had either VSRR (n = 98; 69 reimplantation, 29 remodeling) or Bentall (n = 67) procedures. Patients undergoing Bentall procedure were older (median, 37 vs 36 years; P = .03), had larger median preoperative sinus diameter (5.5 cm vs 5.0 cm; P = .003), more aortic dissections (25.4% vs 4.1%; P.001), higher incidence of moderate or severe aortic insufficiency (49.3% vs 14.4%; P.001) and more urgent or emergent operations (24.6% vs 3.3%; P.001). There were no hospital deaths and 9 late deaths in more than 17 years of follow-up (median, 7.8 deaths). Ten-year survival was 90.5% in patients undergoing Bentall procedure and 96.3% in patients undergoing VSRR (P = .10). Multivariable analysis revealed that VSRR was associated with fewer thromboembolic or hemorrhagic events (hazard ratio, 0.16; 95% confidence interval, 0.03-0.85; P = .03). There was no independent difference in long-term survival, freedom from reoperation, or freedom from endocarditis between the 2 procedures.After prophylactic root replacement in patients with Marfan syndrome, patients undergoing Bentall and valve-sparing procedures have similar late survival, freedom from root reoperation, and freedom from endocarditis. However, valve-sparing procedures result in significantly fewer thromboembolic and hemorrhagic events.