Search

Background: Aortic dilation, stiffening, and dissection are common and potentially lethal complications of Marfan syndrome (MFS) and Loeys-Dietz syndrome (LDS), which involve abnormal transforming growth factor beta (TGF-β) signalling. The relation of aortic dimensions, stiffness, and biomarker levels is unknown. The objective of this study was to measure aortic dimensions, stiffness, TGF-β and matrix metalloproteinase (MMP) levels, and endothelial function in patients with MFS, and to compare TGF-β levels in patients with MFS receiving different therapeutic regimens. Methods: This was a cohort study of 40 MFS and 4 LDS patients and 87 control participants. Aortic dimension and stiffness indexes, including pulse wave velocity (PWV), were measured using echocardiography and Doppler. Total and free TGF-β and MMP blood levels were measured using Quantikine (R&D Systems, Inc, Minneapolis, MN) and Quanterix (Billerica, MA) kits. Endothelial function was measured using brachial artery flow-mediated dilation. Results: PWV was increased in patients with MFS. There were increased MMP-2 levels in those with MFS but no increase in free or total TGF-β or MMP-9 levels compared with control participants. There was no difference in TGF-β levels between MFS patients receiving no medications, angiotensin receptor blockers, and β-blockers. PWV correlated most strongly with age. Endothelial function showed premature gradual decline in patients with MFS. Conclusions: Despite the increased PWV, monitoring aortic stiffness or TGF-β levels would not be helpful in patients with MFS. TGF-β levels were not increased and the increased MMP-2 levels suggest consideration of a different therapeutic target. Résumé: Contexte: La dilatation, la rigidification et la dissection de l’aorte sont des complications fréquentes et parfois mortelles du syndrome de Marfan (SM) et du syndrome de Loeys-Dietz (SLD), qui sont tous deux dûs à une anomalie de la voie de signalisation du facteur de croissance transformant bêta (TGF-β). On ne connaît pas la relation entre les dimensions et la rigidité de l’aorte et la présence de biomarqueurs. Notre étude visait à mesurer les dimensions et la rigidité de l’aorte, les taux de TGF-β et de métalloprotéases matricielles (MMP) et la fonction endothéliale chez des patients atteints du SM, et à les comparer aux taux de TGF-β observés chez des patients également atteints de SM, mais recevant un autre traitement. Méthodologie: Il s’agissait d’une étude de cohorte menée auprès de 40 patients atteints du SM et de quatre patients atteints du SLD, ainsi que de 87 témoins. Les indices des dimensions et de la rigidité aortiques, y compris la vitesse d’onde de pouls (VOP), ont été mesurés par échocardiographie et par échographie Doppler. Les taux sanguins de TGF-β et de MMP totaux et libres ont été mesurés à l’aide de trousses Quantikine (R&D Systems, Inc, Minneapolis, MN) et Quanterix (Billerica, MA). La fonction endothéliale a été mesurée par dilatation liée au flux dans l’artère brachiale. Résultats: La VOP était plus élevée chez les patients atteints du SM. On a aussi observé une hausse des taux de MMP-2 chez les patients atteints de SM, mais aucune augmentation des taux de TGF-β ou de MMP-9 libres ou totaux comparativement aux témoins. Il n’y avait pas de différence entre les taux de TGF-β chez les patients atteints de SM ne recevant aucun traitement, ceux qui prenaient un antagoniste des récepteurs de l’angiotensine et ceux qui prenaient un bêtabloquant. La VOP été plus fortement corrélée avec l’âge. La fonction endothéliale a affiché un déclin progressif prématuré chez les patients atteints du SM. Conclusions: Malgré l’augmentation de la VOP, il ne semble pas utile de surveiller la rigidité aortique ni les taux de TGF-β en cas de SM. Les taux de TGF-β n’étaient pas plus élevés chez les patients atteints du SM, et la hausse des taux de MMP-2 indique qu’il conviendrait de choisir une autre cible thérapeutique.

The purpose of this article was to review the current literature on psychosocial implications of Marfan syndrome (MFS) and its impact on adolescents, adults, their families and to provide important considerations for providers. Since the previous reviews in 2015, numerous studies have been published that are included in the current review. This literature review was conducted using PubMed, Medline, PsychINFO, ERIC, Web of Science, and Academic Search Premier databases and only articles that studied psychosocial factors that influence MFS patients as adolescents, adults, family members, or their interactions with providers were included in this review. Of the 522 articles reviewed, 41 were selected based on the inclusion and exclusion criteria. All articles were peer-reviewed. MFS has various implications that can impact one's life; studies have shown that MFS causes a negative impact on an individual's formative years, quality of life, reproductive decision-making, work participation, and satisfaction with life. Clinicians and multidisciplinary teams should be aware of these factors to provide support focusing on coping strategies for the patient and their family.

Marfan syndrome (MFS) is a genetic disorder that results in accelerated aortic root widening and aneurysm. However, management of MFS patients with blood pressure (BP)‐lowering medications, such as angiotensin II (AngII) receptor blocker (ARB) losartan, continues to pose challenges due to their questionable efficacy at attenuating the rate of aortic root widening in patients. Herein we investigate the anti‐aortic root widening effects of a sub‐BP‐lowering dose valsartan, an ARB previously linked to non‐BP lowering anti‐remodeling effects. Despite absence of BP‐lowering effects, valsartan attenuated MFS aortic root widening by 75.9%, which was similar to a hypotensive dose of losartan (79.4%) when assessed by ultrasound echocardiography. Medial thickening, elastic fiber fragmentation, and phospho‐ERK signaling were also inhibited to a similar degree with both treatments. Valsartan and losartan decreased vascular contractility ex vivo between 60% and 80%, in a nitric oxide (NO)‐sensitive fashion. Valsartan increased acetylcholine (Ach)‐induced vessel relaxation and phospho‐eNOS levels in the aortic vessel supporting BP‐independent activation of protective endothelial function, which is critical to ARB‐mediated aortic root stability. This study supports the concept of achieving aortic root stability with valsartan in absence of BP‐lowering effects, which may help address efficacy and compliance issues with losartan‐based MFS patient management., Inhibition of Marfan aortic root remodeling and widening with blood pressure lowering medications losartan and valsartan. However, valsartan was used at sub‐blood pressure lowering dose, therefore implying blood pressure independence.

Marfan syndrome (MFS) is a connective tissue disorder that results in aortic root widening and aneurysm if unmanaged. We have previously reported doxycycline, a nonselective matrix metalloproteinases (MMPs) inhibitor, to attenuate aortic root widening and improve aortic contractility and elasticity in MFS mice. We were also first to use multiphoton microscopy, a non-invasive and label-free imaging technique, to quantify and link the aortic ultrastructure to possible changes in the skin dermis. Here, we aimed to assess the effects of long-term doxycycline treatment on the aortic ultrastructure and skin dermis of MFS mice through immunohistochemical evaluation and quantification of elastic and collagen content and morphology using multiphoton microscopy. Our results demonstrate a rescue of aortic elastic fiber fragmentation and disorganization accompanied by a decrease in MMP-2 and MMP-9 expression within the aortic wall in doxycycline-treated MFS mice. At 12 months of age, reduced skin dermal thickness was observed in both MFS and control mice, but only dermal thinning in MFS mice was rescued by doxycycline treatment. MMP-2 and MMP-9 expression was reduced in the skin of doxycycline-treated MFS mice. A decrease in dermal thickness was found to be positively associated with increased aortic root elastin disorganization and wall thickness. Our findings confirm the beneficial effects of doxycycline on ultrastructural properties of aortic root as well as on skin elasticity and structural integrity in MFS mice.

Marfan syndrome (MFS) is a genetic disorder that frequently leads to aortic root dissection and aneurysm. Despite promising preclinical and pilot clinical data, a recent large-scale study using antihypertensive angiotensin II (AngII) receptor type 1 (ATR1) blocker losartan has failed to meet expectations at preventing MFS-associated aortic root dilation, casting doubts about optimal therapy. To study the deleterious role of normal ATR1 signaling in aortic root widening, we generated MFS mice lacking ATR1a expression in an attempt to preserve protective ATR2 signaling. Despite being hypotensive and resistant to AngII vasopressor effects, MFS/ATR1a-null mice showed unabated aortic root enlargement and remained fully responsive to losartan, confirming that blood pressure lowering is of minor therapeutic value in MFS and that losartan's antiremodeling properties may be ATR1 independent. Having shown that MFS causes endothelial dysfunction and that losartan can activate endothelial function in mice and patients, we found that nitric oxide synthase (NOS) inhibition renders losartan therapeutically inactive, whereas multiple transgenic and pharmacologic models of endothelial NOS activation block aortic root dilation by correcting extracellular signal–regulated kinase signaling. In vitro , losartan can increase endothelial NO release in the absence of AngII and correct MFS NO levels in vivo . Our data suggest that increased protective endothelial function, rather than ATR1 inhibition or blood pressure lowering, might be of therapeutic significance in preventing aortic root disease in MFS.

Aortic aneurysm is the most life-threatening complication in Marfan syndrome (MFS) patients. Doxycycline, a nonselective matrix metalloproteinases inhibitor, was reported to improve the contractile function and elastic fiber structure and organization in a Marfan mouse aorta using ex vivo small chamber myography. In this study, we assessed the hypothesis that a long-term treatment with doxycycline would reduce aortic root growth, improve aortic wall elasticity as measured by pulse wave velocity, and improve the ultrastructure of elastic fiber in the mouse model of MFS. In our study, longitudinal measurements of aortic root diameters using high-resolution ultrasound imaging display significantly decreased aortic root diameters and lower pulse wave velocity in doxycycline-treated Marfan mice starting at 6 months as compared to their non-treated MFS counterparts. In addition, at the ultrastructural level, our data show that long-term doxycycline treatment corrects the irregularities of elastic fibers within the aortic wall of Marfan mice to the levels similar to those observed in control subjects. Our findings underscore the key role of matrix metalloproteinases during the progression of aortic aneurysm, and provide new insights into the potential therapeutic value of doxycycline in blocking MFS-associated aortic aneurysm.

Marfan syndrome (MFS) is a connective tissue disorder that affects skeletal, ocular, pulmonary, cardiovascular, and central nervous systems. Psychological and physiologic symptoms may lead to diminished quality of life (QoL) in individuals with MFS compared with healthy individuals. Currently, there is little evidence regarding the impact of MFS on executive function and QoL. This study examined perceptions of executive function and QoL among persons with MFS. A total of 318 participants with MFS completed surveys assessing perceptions of executive function abilities and QoL. Responses to executive function questions were grouped using principle component analysis. Responses to QoL questions were separated into overall QoL, questions dealing with satisfaction of QoL, and importance placed on aspect of QoL. Principle component analysis revealed that executive function difficulties, particularly mental fatigue, associated with MFS symptoms affect QoL satisfaction and total QoL. Interestingly, medication status did not significantly impact QoL, over and above executive function difficulties. The findings of the current study suggest that individuals with MFS may experience specific executive function difficulties which impact QoL. These findings also have implications for clinicians who work with individuals with MFS.

The fertility of men with neurofibromatosis 1 (NF1) is reduced. Despite this observation, gonadal function has not been examined in patients with NF1. In order to assess the role of reduced neurofibromin in the testes, we examined testicular morphology and function in an Nf1+/- mouse model. We found that although Nf1+/- male mice are able to reproduce, they have significantly fewer pups per litter than Nf1+/+ control males. Reduced fertility in Nf1+/- male mice is associated with disorganization of the seminiferous epithelium, with exfoliation of germ cells and immature spermatids into the tubule lumen. Morphometric analysis shows that these alterations are associated with decreased Leydig cell numbers and increased spermatid cell numbers. We hypothesized that hyper-activation of Ras in Nf1+/- males affects ectoplasmic specialization, a Sertoli-spermatid adherens junction involved in spermiation. Consistent with this idea, we found increased expression of phosphorylated ERK, a downstream effector of Ras that has been shown to alter ectoplasmic specialization, in Nf1+/- males in comparison to control Nf1+/+ littermates. These data demonstrate that neurofibromin haploinsufficiency impairs spermatogenesis and fertility in a mouse model of NF1.

Regular low-impact physical activity is generally allowed in patients with Marfan syndrome, a connective tissue disorder caused by heterozygous mutations in the fibrillin-1 gene. However, being above average in height encourages young adults with this syndrome to engage in high-intensity contact sports, which unfortunately increases the risk for aortic aneurysm and rupture, the leading cause of death in Marfan syndrome. In this study, we investigated the effects of voluntary (cage-wheel) or forced (treadmill) aerobic exercise at different intensities on aortic function and structure in a mouse model of Marfan syndrome. Four-week-old Marfan and wild-type mice were subjected to voluntary and forced exercise regimens or sedentary lifestyle for 5 mo. Thoracic aortic tissue was isolated and subjected to structural and functional studies. Our data showed that exercise improved aortic wall structure and function in Marfan mice and that the beneficial effect was biphasic, with an optimum at low intensity exercise (55–65% V̇o2max) and tapering off at a higher intensity of exercise (85% V̇o2max). The mechanism underlying the reduced elastin fragmentation in Marfan mice involved reduction of the expression of matrix metalloproteinases 2 and 9 within the aortic wall. These findings present the first evidence of potential beneficial effects of mild exercise on the structural integrity of the aortic wall in Marfan syndrome associated aneurysm. Our finding that moderate, but not strenuous, exercise protects aortic structure and function in a mouse model of Marfan syndrome could have important implications for the medical care of young Marfan patients. NEW & NOTEWORTHY The present study provides conclusive scientific evidence that daily exercise can improve aortic health in a mouse model of Marfan syndrome associated aortic aneurysm, and it establishes the threshold for the exercise intensity beyond which exercise may not be as protective. These findings establish a platform for a new focus on promoting regular exercise in Marfan patients at an optimum intensity and create a paradigm shift in clinical care of Marfan patients suffering from aortic aneurysm complications.

Introduction: Aortic aneurysm is the most life-threatening complication in Marfan syndrome (MFS), a connective tissue disorder caused by mutations in fibrillin-1 gene. We have previously reported that doxycycline, an antibiotic and a general inhibitor of matrix metalloproteinases (MMPs), could improve aortic contractility and elastin fibers structure and organization in a mouse model of MFS. However, the in vivo effects of MMPs inhibition on the progression of aneurysm and pulse wave velocity (PWV) have not been investigated. In this study, we assessed the hypothesis that a long-term treatment with a sub-antibiotic dose of doxycycline would delay the progression of aortic aneurysm and improve the PWV in the Marfan mouse. Methods: In this study, we have used a high-resolution, high-contrast ultrasound imaging technique to conduct a longitudinal study in order to measure aortic diameter (dilatation) and PWV (indication of aortic elasticity/stiffness) in the animals. Marfan (n=12) and control (n=13) mice were given a sub-antibiotic dose of doxycycline in their drinking water at a concentration of 0.24 g/L/day beginning at 6 weeks of age, whereas another group of Marfan (n=12) and control (n=12) mice were given plain drinking water for comparison. At 3, and 6 months of age, aortic diameter and PWV of the experimental animals were measured by ultrasound imaging. Results: At 3 months of age, measurement of aortic root diameter showed significant dilatation in both treated and non-treated Marfan mice as compared to control groups (p < 0.01). However, at 6 months of age, the aortic root diameter in treated Marfan mice was not different from those in controls. The same observation was made for the Sinus of Valsalva region. Especially in this region, treated Marfan aorta showed significantly reduced diameter compared to non-treated Marfan groups (p < 0.05). With respect to the measurement of PWV, a significant increase was observed in 3- and 6-month Marfan mice aorta vs. control (p < 0.01). Interestingly, doxycycline treatment normalized the PWV in 6-month old Marfan mice compared to non-treated Marfan aorta. Conclusions: Our findings show that long-term doxycycline treatment has protective effects in terms of reduction of aortic dilatation and stiffness in Marfan mice.

Aortic aneurysm is the leading cause of death in Marfan syndrome (MFS), a connective tissue disorder caused by mutations in the fibrillin-1 gene. MFS aneurysm is characterized by weakening of the a...

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder presented with multiple cafe-au-lait spots, Lisch nodules,multiple nerve sheath tumors, and cardiovascular complications such as ischemia...

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder, characterized by multiple cafe-au-lait spots, iris harmartomas, multiple nerve sheath tumors. Patients also present with heart and cereb...

Viral myocarditis is a major cause of sudden cardiac death in children and young adults. Among viruses, coxsackievirus B3 (CVB3) is the most common agent for myocarditis. Recently, more consideration has been given to the role of signaling pathways in pathogenesis of enteroviral myocarditis, providing new platform for identifying a new potential therapeutic target for this, so far, incurable disease. Previously, we reported on the role of the protein kinase-B/Akt in CVB3 replication and virus-induced cell injury. Here, we report on regulation of virus-induced Akt activation by the integrin-linked kinase in infected mouse cardiomyocytes and HeLa cells. This study also presents the first observation that inhibition of ILK in CVB3-infected cells significantly improves the viability of infected cells, while blocking viral replication and virus release. Complementary experiments using a constitutively active form of Akt1 revealed that the observed protective effect of ILK inhibition is dependent on the associated downregulation of virus-induced Akt activation. To our knowledge, this is the first report of such beneficial effects of ILK inhibition in a viral infection model and conveys new insights in our efforts to characterize a novel therapeutic target for treatment of enteroviral myocarditis.

In a mouse model of Marfan syndrome, conventional Verhoeff-Van Gieson staining displays severe fragmentation, disorganization and loss of the aortic elastic fiber integrity. However, this method involves chemical fixatives and staining, which may alter the native morphology of elastin and collagen. Thus far, quantitative analysis of fiber damage in aorta and skin in Marfan syndrome has not yet been explored. In this study, we have used an advanced noninvasive and label-free imaging technique, multiphoton microscopy to quantify fiber fragmentation, disorganization, and total volumetric density of aortic and cutaneous elastin and collagen in a mouse model of Marfan syndrome. Aorta and skin samples were harvested from Marfan and control mice aged 3-, 6- and 9-month. Elastin and collagen were identified based on two-photon excitation fluorescence and second-harmonic-generation signals, respectively, without exogenous label. Measurement of fiber length indicated significant fragmentation in Marfan vs. control. Fast Fourier transform algorithm analysis demonstrated markedly lower fiber organization in Marfan mice. Significantly reduced volumetric density of elastin and collagen and thinner skin dermis were observed in Marfan mice. Cutaneous content of elastic fibers and thickness of dermis in 3-month Marfan resembled those in the oldest control mice. Our findings of early signs of fiber degradation and thinning of skin dermis support the potential development of a novel non-invasive approach for early diagnosis of Marfan syndrome.

Marfan syndrome (MFS) is an autosomal-dominant disorder of connective tissue caused by mutations in the fibrillin-1 (FBN1) gene. Mortality is often due to aortic dissection and rupture. We investigated the structural and functional properties of the heart and aorta in a [Fbn1C1039G/+] MFS mouse using high-resolution ultrasound (echo) and optical coherence tomography (OCT). Echo was performed on 6- and 12-month old wild type (WT) and MFS mice (n = 8). In vivo pulse wave velocity (PWV), aortic root diameter, ejection fraction, stroke volume, left ventricular (LV) wall thickness, LV mass and mitral valve early and atrial velocities (E/A) ratio were measured by high resolution echocardiography. OCT was performed on 12-month old WT and MFS fixed mouse hearts to measure ventricular volume and mass. The PWV was significantly increased in 6-mo MFS vs. WT (366.6 ± 19.9 vs. 205.2 ± 18.1 cm/s; p = 0.003) and 12-mo MFS vs. WT (459.5 ± 42.3 vs. 205.3 ± 30.3 cm/s; p< 0.0001). PWV increased with age in MFS mice only. We also found a significantly enlarged aortic root and decreased E/A ratio in MFS mice compared with WT for both age groups. The [Fbn1C1039G/+] mouse model of MFS replicates many of the anomalies of Marfan patients including significant aortic dilation, central aortic stiffness, LV systolic and diastolic dysfunction. This is the first demonstration of the direct measurement in vivo of pulse wave velocity non-invasively in the aortic arch of MFS mice, a robust measure of aortic stiffness and a critical clinical parameter for the assessment of pathology in the Marfan syndrome.

Myocarditis is a cardiac disease associated with inflammation and injury of the myocardium. Several viruses have been associated with myocarditis in humans. However, coxsackievirus B3 is still considered the dominant etiological agent. The observed pathology in viral myocarditis is a result of cooperation or teamwork between viral processes and host immune responses at various stages of disease. Both innate and adaptive immune responses are crucial determinants of the severity of myocardial damage, and contribute to the development of chronic myocarditis and dilated cardiomyopathy following acute viral myocarditis. Advances in genomics and proteomics, and in the use of informatics and biostatistics, are allowing unbiased initial evaluations that can be the basis for testable hypotheses about virus pathogenesis and new therapies.