Dermal fibroblast-to-myofibroblast transition sustained by αvß3 integrin-ILK-Snail1/Slug signaling is a common feature for hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders

Joint Hypermobility Syndrome and Membrane Proteins: A Comprehensive Review

Ehlers-Danlos syndromes (EDSs) constitute a heterogeneous group of connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. Asymptomatic EDSs, joint hypermobility without associated syndromes, EDSs, and hypermobility spectrum disorders are the commonest phenotypes associated with joint hypermobility. Joint hypermobility syndrome (JHS) is a connective tissue disorder characterized by extreme flexibility of the joints, along with pain and other symptoms. JHS can be a sign of a more serious underlying genetic condition, such as EDS, which affects the cartilage, bone, fat, and blood. The exact cause of JHS could be related to genetic changes in the proteins that add flexibility and strength to the joints, ligaments, and tendons, such as collagen. Membrane proteins are a class of proteins embedded in the cell membrane and play a crucial role in cell signaling, transport, and adhesion. Dysregulated membrane proteins have been implicated in a variety of diseases, including cancer, cardiovascular disease, and neurological disorders; recent studies have suggested that membrane proteins may also play a role in the pathogenesis of JHS. This article presents an exploration of the causative factors contributing to musculoskeletal pain in individuals with hypermobility, based on research findings. It aims to provide an understanding of JHS and its association with membrane proteins, addressing the clinical manifestations, pathogenesis, diagnosis, and management of JHS.

Genetic complexity of diagnostically unresolved Ehlers-Danlos syndrome

BACKGROUND

The Ehlers-Danlos syndromes (EDS) are heritable disorders of connective tissue (HDCT), reclassified in the 2017 nosology into 13 subtypes. The genetic basis for hypermobile Ehlers-Danlos syndrome (hEDS) remains unknown.

METHODS

Whole exome sequencing (WES) was undertaken on 174 EDS patients recruited from a national diagnostic service for complex EDS and a specialist clinic for hEDS. Patients had already undergone expert phenotyping, laboratory investigation and gene sequencing, but were without a genetic diagnosis. Filtered WES data were reviewed for genes underlying Mendelian disorders and loci reported in EDS linkage, transcriptome and genome-wide association studies (GWAS). A genetic burden analysis (Minor Allele Frequency (MAF) <0.05) incorporating 248 Avon Longitudinal Study of Parents and Children (ALSPAC) controls sequenced as part of the UK10K study was undertaken using TASER methodology.

RESULTS

Heterozygous pathogenic (P) or likely pathogenic (LP) variants were identified in known EDS and Loeys-Dietz (LDS) genes. Multiple variants of uncertain significance where segregation and functional analysis may enable reclassification were found in genes associated with EDS, LDS, heritable thoracic aortic disease (HTAD), Mendelian disorders with EDS symptomatology and syndromes with EDS-like features. Genetic burden analysis revealed a number of novel loci, although none reached the threshold for genome-wide significance. Variants with biological plausibility were found in genes and pathways not currently associated with EDS or HTAD.

CONCLUSIONS

We demonstrate the clinical utility of large panel-based sequencing and WES for patients with complex EDS in distinguishing rare EDS subtypes, LDS and related syndromes. Although many of the P and LP variants reported in this cohort would be identified with current panel testing, they were not at the time of this study, highlighting the use of extended panels and WES as a clinical tool for complex EDS. Our results are consistent with the complex genetic architecture of EDS and suggest a number of novel hEDS and HTAD candidate genes and pathways.

Integrative medicine for hypermobility spectrum disorders (HSD) and Ehlers-Danlos syndromes (EDS): a feasibility study

PURPOSE

Hypermobility spectrum disorders (HSD) and Ehlers-Danlos syndromes (EDS) are multisystem conditions marked by dysfunctional connective tissue. This feasibility study evaluated a 9-week integrative medicine program in this population.

METHODS

Using a single-arm study design, adults with HSD or EDS were given recommendations for an anti-inflammatory Mediterranean diet and self-management with additional behavioral and psychosocial support. Preliminary data on feasibility based on recruitment and retention, adherence to the diet, mobile app tracking, changes to perceived well-being via health outcomes, and satisfaction with care were obtained.

RESULTS

Thirteen participants were enrolled within a 4-month timeframe. Eight participants completed the study. Three participants met dietary tracking requirement in at least 4 of 8 intervention weeks and met the macronutrient requirements in at least half of the weeks tracked. No decreases in VAS pain scores after 5 and 9 weeks were noted; however, 62.5% (n = 5) of participants had decreased pain at 9 weeks, compared to baseline. There were significant improvements (p<.05) in six of twelve measurements of satisfaction with care at the end of the intervention.

CONCLUSION

This study provides a foundation for future research on patient experience and introduces a novel treatment paradigm focused on nutrition and self-management.

Trial Registration: National Institutes of Health clinicaltrials.gov; identifier: NCT04734041.

IMPLICATIONS FOR REHABILITATION

Lifestyle and dietary interventions are relatively safe and well tolerated in the hypermobility spectrum disorder (HSD) and Ehlers-Danlos disorder (EDS) population.Participants in our 9-week integrative medicine program actively engaged in self-management of their condition and showed promising adherence to dietary and tracking requirements.Effective treatment of the intricacies and dynamics of these highly variable and clinically heterogeneous disorders may require a network of healthcare providers, integrative healthcare, as well as behavioral and psychosocial support.Dietary tracking through mobile apps might help promote self-efficacy and adherence to dietary changes.Symptom tracking might be an effective way for patients to track changes to their health and could provide valuable information for health professionals engaged in managing the disorders.

Looking back and beyond the 2017 diagnostic criteria for hypermobile Ehlers-Danlos syndrome: A retrospective cross-sectional study from an Italian reference center

The most common conditions with symptomatic joint hypermobility are hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD). Diagnosing these overlapping connective tissue disorders remains challenging due to the lack of established causes and reliable diagnostic tests. hEDS is diagnosed applying the 2017 diagnostic criteria, and patients with symptomatic joint hypermobility but not fulfilling these criteria are labeled as HSD, which is not officially recognized by all healthcare systems. The 2017 criteria were introduced to improve diagnostic specificity but have faced criticism for being too stringent and failing to adequately capture the multisystemic involvement of hEDS. Herein, we retrospectively evaluated 327 patients from 213 families with a prior diagnosis of hypermobility type EDS or joint hypermobility syndrome based on Villefranche and Brighton criteria, to assess the effectiveness of the 2017 criteria in distinguishing between hEDS and HSD and document the frequencies of extra-articular manifestations. Based on our findings, we propose that the 2017 criteria should be made less stringent to include a greater number of patients who are currently encompassed within the HSD category. This will lead to improved diagnostic accuracy and enhanced patient care by properly capturing the diverse range of symptoms and manifestations present within the hEDS/HSD spectrum.

Change in gliding properties of the iliotibial tract in hypermobile Ehlers-Danlos Syndrome

PURPOSE

Fascial changes in hypermobile Ehlers-Danlos syndrome (hEDS), a heritable connective tissue disorder, can be used visualized with sonoelastography. The purpose of this study was to explore the inter-fascial gliding characteristics in hEDS.

METHODS

In 9 subjects, the right iliotibial tract was examined with ultrasonography. Tissue displacements of the iliotibial tract were estimated from ultrasound data using cross-correlation techniques.

RESULTS

In hEDS subjects, shear strain was 46.2%, lower than those with lower limb pain without hEDS (89.5%) and in control subjects without hEDS and without pain (121.1%).

CONCLUSION

Extracellular matrix changes in hEDS may manifest as reduced inter-fascial plane gliding.

“Long COVID-19” and viral “fibromyalgia-ness”: Suggesting a mechanistic role for fascial myofibroblasts (Nineveh, the shadow is in the fascia)

The coronavirus pandemic has led to a wave of chronic disease cases; “Long COVID-19” is recognized as a new medical entity and resembles “fibromyalgia” which, likewise, lacks a clear mechanism. Observational studies indicate that up to 30%–40% of convalescent COVID-19 patients develop chronic widespread pain and fatigue and fulfill the 2016 diagnostic criteria for “fibromyalgia.” A recent study suggested a theoretical neuro-biomechanical model (coined “Fascial Armoring”) to help explain the pathogenesis and cellular pathway of fibromyalgia, pointing toward mechanical abnormalities in connective tissue and fascia, driven by contractile myo/fibroblasts and altered extracellular matrix remodeling with downstream corresponding neurophysiological aberrations. This may help explain several of fibromyalgia’s manifestations such as pain, distribution of pain, trigger points/tender spots, hyperalgesia, chronic fatigue, cardiovascular abnormalities, metabolic abnormalities, autonomic abnormalities, small fiber neuropathy, various psychosomatic symptoms, lack of obvious inflammation, and silent imaging investigations. Pro-inflammatory and pro-fibrotic pathways provide input into this mechanism via stimulation of proto/myofibroblasts. In this hypothesis and theory paper the theoretical model of Fascial Armoring is presented to help explain the pathogenesis and manifestations of “long COVID-19” as a disease of immuno-rheumo-psycho-neurology. The model is also used to make testable experimental predictions on investigations and predict risk and relieving factors.

Suggesting a mechanism for acupuncture as a global percutaneous needle fasciotomy that respects tensegrity principles for treating fibromyalgia

Acupuncture is a minimally invasive therapeutic method that uses small caliber needles while inserting them through the skin into various areas of the body. Some empirical studies find evidence to support the use of acupuncture as a treatment for certain medical conditions, however, this peculiar practice is widely considered as the domain of alternative and non-evidence-based medicine. Several mechanisms have been suggested in an attempt to explain the therapeutic action of acupuncture, but the way in which acupuncture alleviates chronic non-cancer pain or psychosomatic and psychiatric disorders is not fully understood. A recent study suggested a theoretical model (coined "Fascial Armoring") with a cellular pathway to help explain the pathogenesis of myofascial pain/fibromyalgia syndrome and functional psychosomatic syndromes. It proposes that these syndromes are a spectrum of a single medical entity that involves myofibroblasts with contractile activity in fascia and aberrant extracellular matrix (ECM) remodeling, which may lead to widespread mechanical tension and compression. This can help explain diverse psycho-somatic manifestations of fibromyalgia-like syndromes. Fascia is a continuous interconnected tissue network that extends throughout the body and has qualities of bio-tensegrity. Previous studies show that a mechanical action by needling induces soft tissue changes and lowers the shear modulus and stiffness in myofascial tissue. This hypothesis and theory paper offers a new mechanism for acupuncture therapy as a global percutaneous needle fasciotomy that respects tensegrity principles (tensegrity-based needling), in light of the theoretical model of "Fascial Armoring." The translation of this model to other medical conditions carries potential to advance therapies. These days opioid overuse and over-prescription are ubiquitous, as well as chronic pain and suffering.

Extracellular matrix stiffness-The central cue for skin fibrosis

Skin fibrosis is a physiopathological process featuring the excessive deposition of extracellular matrix (ECM), which is the main architecture that provides structural support and constitutes the microenvironment for various cellular behaviors. Recently, increasing interest has been drawn to the relationship between the mechanical properties of the ECM and the initiation and modulation of skin fibrosis, with the engagement of a complex network of signaling pathways, the activation of mechanosensitive proteins, and changes in immunoregulation and metabolism. Simultaneous with the progression of skin fibrosis, the stiffness of ECM increases, which in turn perturbs mechanical and humoral homeostasis to drive cell fate toward an outcome that maintains and enhances the fibrosis process, thus forming a pro-fibrotic "positive feedback loop". In this review, we highlighted the central role of the ECM and its dynamic changes at both the molecular and cellular levels in skin fibrosis. We paid special attention to signaling pathways regulated by mechanical cues in ECM remodeling. We also systematically summarized antifibrotic interventions targeting the ECM, hopefully enlightening new strategies for fibrotic diseases.

RNA-Seq of Dermal Fibroblasts from Patients with Hypermobile Ehlers-Danlos Syndrome and Hypermobility Spectrum Disorders Supports Their Categorization as a Single Entity with Involvement of Extracellular Matrix Degrading and Proinflammatory Pathomechanisms

Hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD) are clinically overlapping connective tissue disorders of unknown etiology and without any validated diagnostic biomarker and specific therapies. Herein, we in-depth characterized the cellular phenotype and gene expression profile of hEDS and HSD dermal fibroblasts by immunofluorescence, amplicon-based RNA-seq, and qPCR. We demonstrated that both cell types show a common cellular trait, i.e., generalized extracellular matrix (ECM) disarray, myofibroblast differentiation, and dysregulated gene expression. Functional enrichment and pathway analyses clustered gene expression changes in different biological networks that are likely relevant for the disease pathophysiology. Specifically, the complex gene expression dysregulation (mainly involving growth factors, structural ECM components, ECM-modifying enzymes, cytoskeletal proteins, and different signal transducers), is expected to perturb many ECM-related processes including cell adhesion, migration, proliferation, and differentiation. Based on these findings, we propose a disease model in which an unbalanced ECM remodeling triggers a vicious cycle with a synergistic contribution of ECM degradation products and proinflammatory mediators leading to a functional impairment of different connective tissues reflecting the multisystemic presentation of hEDS/HSD patients. Our results offer many promising clues for translational research aimed to define molecular bases, diagnostic biomarkers, and specific therapies for these challenging connective tissue disorders.

Mechanobiology in the Comorbidities of Ehlers Danlos Syndrome

Ehlers-Danlos Syndromes (EDSs) are a group of connective tissue disorders, characterized by skin stretchability, joint hypermobility and instability. Mechanically, various tissues from EDS patients exhibit lowered elastic modulus and lowered ultimate strength. This change in mechanics has been associated with EDS symptoms. However, recent evidence points toward a possibility that the comorbidities of EDS could be also associated with reduced tissue stiffness. In this review, we focus on mast cell activation syndrome and impaired wound healing, comorbidities associated with the classical type (cEDS) and the hypermobile type (hEDS), respectively, and discuss potential mechanobiological pathways involved in the comorbidities.

Scoping review and interpretation of myofascial pain/fibromyalgia syndrome: An attempt to assemble a medical puzzle

BACKGROUND

Myofascial Pain Syndrome (MPS) is a common, overlooked, and underdiagnosed condition and has significant burden. MPS is often dismissed by clinicians while patients remain in pain for years. MPS can evolve into fibromyalgia, however, effective treatments for both are lacking due to absence of a clear mechanism. Many studies focus on central sensitization. Therefore, the purpose of this scoping review is to systematically search cross-disciplinary empirical studies of MPS, focusing on mechanical aspects, and suggest an organic mechanism explaining how it might evolve into fibromyalgia. Hopefully, it will advance our understanding of this disease.

METHODS

Systematically searched multiple phrases in MEDLINE, EMBASE, COCHRANE, PEDro, and medRxiv, majority with no time limit. Inclusion/exclusion based on title and abstract, then full text inspection. Additional literature added on relevant side topics. Review follows PRISMA-ScR guidelines. PROSPERO yet to adapt registration for scoping reviews.

FINDINGS

799 records included. Fascia can adapt to various states by reversibly changing biomechanical and physical properties. Trigger points, tension, and pain are a hallmark of MPS. Myofibroblasts play a role in sustained myofascial tension. Tension can propagate in fascia, possibly supporting a tensegrity framework. Movement and mechanical interventions treat and prevent MPS, while living sedentarily predisposes to MPS and recurrence.

CONCLUSIONS

MPS can be seen as a pathological state of imbalance in a natural process; manifesting from the inherent properties of the fascia, triggered by a disrupted biomechanical interplay. MPS might evolve into fibromyalgia through deranged myofibroblasts in connective tissue ("fascial armoring"). Movement is an underemployed requisite in modern lifestyle. Lifestyle is linked to pain and suffering. The mechanism of needling is suggested to be more mechanical than currently thought. A "global percutaneous needle fasciotomy" that respects tensegrity principles may treat MPS/fibromyalgia more effectively. "Functional-somatic syndromes" can be seen as one entity (myofibroblast-generated-tensegrity-tension), sharing a common rheuma-psycho-neurological mechanism.

Matrix Metalloproteinases Inhibition by Doxycycline Rescues Extracellular Matrix Organization and Partly Reverts Myofibroblast Differentiation in Hypermobile Ehlers-Danlos Syndrome Dermal Fibroblasts: A Potential Therapeutic Target?

Hypermobile Ehlers-Danlos syndrome (hEDS) is the most frequent type of EDS and is characterized by generalized joint hypermobility and musculoskeletal manifestations which are associated with chronic pain, and mild skin involvement along with the presence of more than a few comorbid conditions. Despite numerous research efforts, no causative gene(s) or validated biomarkers have been identified and insights into the disease-causing mechanisms remain scarce. Variability in the spectrum and severity of symptoms and progression of hEDS patients’ phenotype likely depend on a combination of age, gender, lifestyle, and the probable multitude of genes involved in hEDS. However, considering the clinical overlap with other EDS forms, which lead to abnormalities in extracellular matrix (ECM), it is plausible that the mechanisms underlying hEDS pathogenesis also affect the ECM to a certain extent. Herein, we performed a series of in vitro studies on the secretome of hEDS dermal fibroblasts that revealed a matrix metalloproteinases (MMPs) dysfunction as one of the major disease drivers by causing a detrimental feedback loop of excessive ECM degradation coupled with myofibroblast differentiation. We demonstrated that doxycycline-mediated inhibition of MMPs rescues in hEDS cells a control-like ECM organization and induces a partial reversal of their myofibroblast-like features, thus offering encouraging clues for translational studies confirming MMPs as a potential therapeutic target in hEDS with the expectation to improve patients’ quality of life and alleviate their disabilities.

Fascial thickness and stiffness in hypermobile Ehlers-Danlos syndrome

There is a high prevalence of myofascial pain in people with hypermobile Ehlers-Danlos Syndrome (hEDS). The fascial origin of pain may correspond to changes in the extracellular matrix. The objective of this study was to investigate structural changes in fascia in hEDS. A series of 65 patients were examined prospectively-26 with hEDS, and 39 subjects with chronic neck, knee, or back pain without hEDS. The deep fascia of the sternocleidomastoid, iliotibial tract, and iliac fascia were examined with B-mode ultrasound and strain elastography, and the thicknesses were measured. Stiffness (strain index) was measured semi-quantitatively using elastography comparing fascia to muscle. Differences between groups were compared using one-way analysis of variance. hEDS subjects had a higher mean thickness in the deep fascia of the sternocleidomastoid compared with non-hEDS subjects. There was no significant difference in thickness of the iliac fascia and iliotibial tract between groups. Non-hEDS subjects with pain had a higher strain index (more softening of the fascia with relative stiffening of the muscle) compared with hEDS subjects and non-hEDS subjects without back or knee pain. In myofascial pain, softening of the fascia may occur from increase in extracellular matrix content and relative increase in stiffness of the muscle; this change is not as pronounced in hEDS.

Hypermobile Ehlers-Danlos syndrome: A review and a critical appraisal of published genetic research to date

The Ehlers-Danlos syndromes (EDS) are a collection of rare hereditary connective tissue disorders with heterogeneous phenotypes, usually diagnosed following clinical examination and confirmatory genetic testing. Diagnosis of the commonest subtype, hypermobile Ehlers-Danlos Syndrome (hEDS), relies solely on a clinical diagnosis since its molecular aetiology remains unknown. We performed an up-to-date literature search and selected 11 out of 304 publications according to a set of established criteria. Studies reporting variants affecting collagen proteins were found to be hindered by cohort misclassification and subsequent lack of reproducibility of these genetic findings. The role of the described variants affecting Tenascin-X and LZTS1 is yet to be demonstrated in the majority of hEDS cases, while the functional implication of associated signaling pathways and genes requires further elucidation. The available literature on the genetics of hEDS is scant, dispersed and conflicting due to out-dated nosology terminology. Recent literature has suggested the role of several promising candidate mechanisms which may be linked to the underlying molecular aetiology. Knowledge of the molecular genetic basis of hEDS is expected to increase in the near future through the mainstream use of high-throughput sequencing combined with the updated classification of EDS, and the upcoming Hypermobile Ehlers-Danlos Genetic Evaluation (HEDGE) study.

Hypermobile Ehlers-Danlos syndrome (hEDS) phenotype in fragile X premutation carriers: case series

BACKGROUND

While an association between full mutation CGG-repeat expansions of the Fragile X Mental Retardation 1 (FMR1) gene and connective tissue problems are clearly described, problems in fragile X premutation carriers (fXPCs) CGG-repeat range (55-200 repeats) of the FMR1 gene may be overlooked.

OBJECTIVE

To report five FMR1 fXPCs cases with the hypermobile Ehlers-Danlos syndrome (hEDS) phenotype.

METHODS

We collected medical histories and FMR1 molecular measures from five cases who presented with joint hypermobility and loose connective tissue and met inclusion criteria for hEDS.

RESULTS

Five cases were female and ranged between 16 and 49 years. The range of CGG-repeat allele sizes ranged from 66 to 150 repeats. All had symptoms of hEDS since early childhood. Commonalities in molecular pathogenesis and coexisting conditions between the fXPCs and hEDS are also presented. The premutation can lead to a reduction of fragile X mental retardation protein, which is crucial in maintaining functions of the extracellular matrix-related proteins, particularly matrix metallopeptidase 9 and elastin. Moreover, elevated FMR1 messenger RNA causes sequestration of proteins, which results in RNA toxicity.

CONCLUSION

Both hEDS phenotype and premutation involvement may co-occur because of related commonalities in pathogenesis.

The Role of Cell Adhesion and Cytoskeleton Dynamics in the Pathogenesis of the Ehlers-Danlos Syndromes and Hypermobility Spectrum Disorders

The Ehlers-Danlos syndromes (EDS) are a group of 13 disorders, clinically defined through features of joint hypermobility, skin hyperextensibility, and tissue fragility. Most subtypes are caused by mutations in genes affecting the structure or processing of the extracellular matrix (ECM) protein collagen. The Hypermobility Spectrum Disorders (HSDs) are clinically indistinguishable disorders, but are considered to lack a genetic basis. The pathogenesis of all these disorders, however, remains poorly understood. Genotype-phenotype correlations are limited, and findings of aberrant collagen fibrils are inconsistent and associate poorly with the subtype and severity of the disorder. The defective ECM, however, also has consequences for cellular processes. EDS/HSD fibroblasts exhibit a dysfunctional phenotype including impairments in cell adhesion and cytoskeleton organization, though the pathological significance of this has remained unclear. Recent advances in our understanding of fibroblast mechanobiology suggest these changes may actually reflect features of a pathomechanism we herein define. This review departs from the traditional view of EDS/HSD, where pathogenesis is mediated by the structurally defective ECM. Instead, we propose EDS/HSD may be a disorder of membrane-bound collagen, and consider how aberrations in cell adhesion and cytoskeleton dynamics could drive the abnormal properties of the connective tissue, and be responsible for the pathogenesis of EDS/HSD.

Hypermobile Ehlers-Danlos syndromes: Complex phenotypes, challenging diagnoses, and poorly understood causes

The Ehlers-Danlos syndromes (EDS) are a group of heritable, connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. There is phenotypic and genetic variation among the 13 subtypes. The initial genetic findings on EDS were related to alterations in fibrillar collagen, but the elucidation of the molecular basis of many of the subtypes revealed several genes not involved in collagen biosynthesis or structure. However, the genetic basis of the hypermobile type of EDS (hEDS) is still unknown. hEDS is the most common type of EDS and involves generalized joint hypermobility, musculoskeletal manifestations, and mild skin involvement along with the presence of several comorbid conditions. Variability in the spectrum and severity of symptoms and progression of patient phenotype likely depend on age, gender, lifestyle, and expression domains of the EDS genes during development and postnatal life. In this review, we summarize the current molecular, genetic, epidemiologic, and pathogenetic findings related to EDS with a focus on the hypermobile type.

Biological insights in the pathogenesis of hypermobile Ehlers-Danlos syndrome from proteome profiling of patients' dermal myofibroblasts

Hypermobile Ehlers-Danlos syndrome (hEDS), mainly characterized by generalized joint hypermobility and its complications, minor skin changes, and apparently segregating with an autosomal dominant pattern, is still without a known molecular basis. Hence, its diagnosis is only clinical based on a strict set of criteria defined in the revised EDS nosology. Moreover, the hEDS phenotypic spectrum is wide-ranging and comprises multiple associated signs and symptoms shared with other heritable or acquired connective tissue disorders and chronic inflammatory diseases. In this complex scenario, we previously demonstrated that hEDS patients' skin fibroblasts show phenotypic features of myofibroblasts, widespread extracellular matrix (ECM) disarray, perturbation of ECM-cell contacts, and dysregulated expression of genes involved in connective tissue architecture and related to inflammatory and pain responses. Herein, the cellular proteome of 6 hEDS dermal myofibroblasts was compared to that of 12 control fibroblasts to deepen the knowledge on mechanisms involved in the disease pathogenesis. Qualitative and quantitative differences were assessed based on top-down and bottom-up approaches and some differentially expressed proteins were proofed by biochemical analyses. Proteomics disclosed the differential expression of proteins principally implicated in cytoskeleton organization, energy metabolism and redox balance, proteostasis, and intracellular trafficking. Our findings offer a comprehensive view of dysregulated protein networks and related pathways likely associated with the hEDS pathophysiology. The present results can be regarded as a starting point for future in-depth investigations aimed to decipher the functional impact of potential bioactive molecules for the development of targeted management and therapies.

Pelvic Girdle Pain, Hypermobility Spectrum Disorder and Hypermobility-Type Ehlers-Danlos Syndrome: A Narrative Literature Review

Pelvic girdle pain (PGP) refers specifically to musculoskeletal pain localised to the pelvic ring and can be present at its anterior and/or posterior aspects. Causes such as trauma, infection and pregnancy have been well-established, while patients with hypermobile joints are at greater risk of developing PGP. Research exploring this association is limited and of varying quality. In the present study we report on the incidence, pathophysiology, diagnostic and treatment modalities for PGP in patients suffering from Hypermobility Spectrum Disorder (HSD) and Hypermobility-Type Ehlers-Danlos Syndrome (hEDS). Recommendations are made for clinical practice by elaborating on screening, diagnosis and management of such patients to provide a holistic approach to their care. It appears that this cohort of patients are at greater risk particularly of mental health issues. Moreover over, they may require a multidisciplinary approach for their management. Ongoing research is still required to expand our understanding of the relationship between PGP, HSD and hEDS by appropriately diagnosing patients using the latest updated terminologies and by conducting randomised control trials to compare outcomes of interventions using standardised patient reported outcome measures.

Chronic mucocutaneous candidiasis and connective tissue disorder in humans with impaired JNK1-dependent responses to IL-17A/F and TGF-β

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' T_H17 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.

Colonoscopy is safe and not associated with higher pain scores in patients with hypermobility spectrum disorder: results from an exploratory prospective study

BACKGROUND

Patient perception of colonoscopy varies greatly. Young slender women and patients with irritable bowel syndrome (IBS) appear to be at risk for periprocedural pain. Recent evidence suggests a high prevalence of joint hypermobility related connective tissue disorders in this population. Therefore, we aimed to investigate whether hypermobility spectrum disorder (HSD) is associated with increased pain during colonoscopy.

METHODS

We prospectively included patients undergoing routine colonoscopy. Subjects were assessed for HSD using the 2017 criteria, and IBS and functional dyspepsia using the Rome III criteria. After colonoscopy and recovery from sedation, patients were asked to report pain scores on a 100-mm visual analogue scale (VAS). In addition, caecal intubation time was measured, endoscopists scored the difficulty of the procedure (100-mm VAS) and procedure-related adverse events were registered.

RESULTS

Of 200 included patients, 22 (11%) met criteria for HSD. A female predominance was observed in patients with HSD (86.4% versus 49.4%, p < 0.001). A crude linear regression model demonstrated that pain scores were 13.30 mm higher in patients with HSD versus non-HSD patients (95% CI 0.07 - 26.53, p = 0.049). When subsequently correcting for possible confounding factors, however, this difference in pain scores could be explained by a confounding effect of female gender. Caecal intubation time, perceived procedural difficulty and complication rate did not differ significantly between groups.

CONCLUSION

HSD does not seem to be a predictor of painful colonoscopy, probably due to female gender as a confounding factor. In addition, performing colonoscopy is not more complicated in patients with HSD versus non-HSD patients, nor is it associated with more adverse events.

Severity classes in adults with hypermobile Ehlers-Danlos syndrome/hypermobility spectrum disorders: a pilot study of 105 Italian patients

OBJECTIVES

This study is aimed at identifying discrete severity classes among adults with hypermobile Ehlers-Danlos syndrome (hEDS)/hypermobility spectrum disorders (HSD).

METHODS

Subjects were selected according to the old and new nomenclatures and all completed a set of questionnaires exploring pain, fatigue, dysautonomic symptoms, coordination and attention/concentration deficits and quality of life in general. Data were investigated by hierarchical clustering on principal components. Cluster comparisons were then performed by using the two-sample unpaired t test and the standardized mean difference was reported as a measure of effect size. Conditional classification tree analysis and multivariable logistic regression were carried out in order to identify the profiles that were at higher risk to belong to the more severe cluster. Weighted linear combination was used to identify a numerical score measuring this risk.

RESULTS

A total of 105 patients were selected and distributed in two distinct severity groups. These groups were statistically separated on the basis of 47 of 59 items/characteristics. One group featured the worse values of most questionnaire items (complex/severe cluster) and the other was dominated by the better values (simplex/milder cluster). Only three items were able to stratify patients according to their risk to belong to the complex cluster. A severity score was then constructed on these three items.

CONCLUSION

Adults with hEDS/HSD can be separated in two severity classes, which do not mirror either the old or new criteria for hEDS. The identified severity score could allow a bi-dimensional approach to adults with hEDS/HSD for optimal management planning.

High Prevalence of Connective Tissue Gene Variants in Professional Ballet

BACKGROUND

There is a high prevalence of hypermobility spectrum disorder (HSD) in dancers. While there is no known genetic variant for HSD, hypermobile Ehlers-Danlos syndrome is a genetic disorder that exists within HSD. There are many connective tissue disorders (CTDs) with known (and unknown) genes associated with hypermobility. Hypermobility has distinct advantages for participation in flexibility sports, including ballet.

PURPOSE

To determine the prevalence of gene variants associated with hypermobility in a large professional ballet company.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

In this cross-sectional investigation, 51 professional male and female dancers from a large metropolitan ballet company were eligible and offered participation after an oral and written informed consent process. Whole blood was obtained from peripheral venipuncture, and DNA was isolated. Isolated DNA was subsequently enriched for the coding exons of 60 genes associated with CTD that included hypermobility as a phenotype, including Ehlers-Danlos syndromes, osteogenesis imperfecta, Marfan syndrome, and others. Genes were targeted with hybrid capture technology. Prepared DNA libraries were then sequenced with next-generation sequencing technology. Genetic database search tools (Human Gene Mutation Database and e!Ensembl, http://useast.ensembl.org/ ) were used to query specific variants. Descriptive statistics were calculated.

RESULTS

Of 51 dancers, 32 (63%) agreed to participate in DNA analysis (mean ± SD age, 24.3 ± 4.4 years; 18 men, 14 women). Twenty-eight dancers had at least 1 variant in the 60 genes tested, for an 88% prevalence. A total of 80 variants were found. A variant in 26 of the 60 genes was found in at least 1 dancer. Among the 28 dancers with variants, 16 were found in the TTN gene; 10 in ZNF469; 5 in RYR1; 4 in COL12A1; 3 in ABCC6 and COL6A2; 2 in ADAMTS2, CBS, COL1A2, COL6A3, SLC2A10, TNC, and TNXB; and 1 in ATP6V0A2, B4GALT7, BMP1, COL11A1, COL5A2, COL6A1, DSE, FBN1, FBN2, NOTCH1, PRDM5, SMAD3, and TGFBR1. Nine variants found in this population have never been reported. No identified variant was identical to any other variant. No identified variant was known to be disease causing. In the general population, the prevalence of each variant ranges from never reported to 0.33%. In the study population, the prevalence of each variant was 3.13%. There was no association between hypermobility scores and genetic variants.

CONCLUSION

Genetic variants in CTD-associated genes are highly prevalent (88%) in professional ballet dancers. This may significantly account for the high degree of motion in this population.

COL1-related overlap disorder: A novel connective tissue disorder incorporating the osteogenesis imperfecta/Ehlers-Danlos syndrome overlap

The 2017 classification of Ehlers-Danlos syndromes (EDS) identifies three types associated with causative variants in COL1A1/COL1A2 and distinct from osteogenesis imperfecta (OI). Previously, patients have been described with variable features of both disorders, and causative variants in COL1A1/COL1A2; but this phenotype has not been included in the current classification. Here, we expand and re-define this OI/EDS overlap as a missing EDS type. Twenty-one individuals from 13 families were reported, in whom COL1A1/COL1A2 variants were found after a suspicion of EDS. None of them could be classified as affected by OI or by any of the three recognized EDS variants associated with COL1A1/COL1A2. This phenotype is dominated by EDS-related features. OI-related features were limited to mildly reduced bone mass, occasional fractures and short stature. Eight COL1A1/COL1A2 variants were novel and five recurrent with a predominance of glycine substitutions affecting residues within the procollagen N-proteinase cleavage site of α1(I) and α2(I) procollagens. Selected variants were investigated by biochemical, ultrastructural and immunofluorescence studies. The pattern of observed changes in the dermis and in vitro for selected variants was more typical of EDS rather than OI. Our findings indicate the existence of a wider recognizable spectrum associated with COL1A1/COL1A2.

Clinical and Molecular Characterization of Classical-Like Ehlers-Danlos Syndrome Due to a Novel TNXB Variant

The Ehlers-Danlos syndromes (EDS) constitute a clinically and genetically heterogeneous group of connective tissue disorders. Tenascin X (TNX) deficiency is a rare type of EDS, defined as classical-like EDS (clEDS), since it phenotypically resembles the classical form of EDS, though lacking atrophic scarring. Although most patients display a well-defined phenotype, the diagnosis of TNX-deficiency is often delayed or overlooked. Here, we described an additional patient with clEDS due to a homozygous null-mutation in the TNXB gene. A review of the literature was performed, summarizing the most important and distinctive clinical signs of this disorder. Characterization of the cellular phenotype demonstrated a distinct organization of the extracellular matrix (ECM), whereby clEDS distinguishes itself from most other EDS subtypes by normal deposition of fibronectin in the ECM and a normal organization of the α5β1 integrin.

Cellular and Molecular Mechanisms in the Pathogenesis of Classical, Vascular, and Hypermobile Ehlers‒Danlos Syndromes

The Ehlers‒Danlos syndromes (EDS) constitute a heterogenous group of connective tissue disorders characterized by joint hypermobility, skin abnormalities, and vascular fragility. The latest nosology recognizes 13 types caused by pathogenic variants in genes encoding collagens and other molecules involved in collagen processing and extracellular matrix (ECM) biology. Classical (cEDS), vascular (vEDS), and hypermobile (hEDS) EDS are the most frequent types. cEDS and vEDS are caused respectively by defects in collagen V and collagen III, whereas the molecular basis of hEDS is unknown. For these disorders, the molecular pathology remains poorly studied. Herein, we review, expand, and compare our previous transcriptome and protein studies on dermal fibroblasts from cEDS, vEDS, and hEDS patients, offering insights and perspectives in their molecular mechanisms. These cells, though sharing a pathological ECM remodeling, show differences in the underlying pathomechanisms. In cEDS and vEDS fibroblasts, key processes such as collagen biosynthesis/processing, protein folding quality control, endoplasmic reticulum homeostasis, autophagy, and wound healing are perturbed. In hEDS cells, gene expression changes related to cell-matrix interactions, inflammatory/pain responses, and acquisition of an in vitro pro-inflammatory myofibroblast-like phenotype may contribute to the complex pathogenesis of the disorder. Finally, emerging findings from miRNA profiling of hEDS fibroblasts are discussed to add some novel biological aspects about hEDS etiopathogenesis.

TAB2 c.1398dup variant leads to haploinsufficiency and impairs extracellular matrix homeostasis

Transforming growth factor β-activated kinase 1 (TAK1) mediates multiple biological processes through the nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and the mitogen-activated protein kinase (MAPK) signaling pathways. TAK1 activation is tightly regulated by its binding partners (TABs). In particular, binding with TAB2 is crucial for cardiovascular development and extracellular matrix (ECM) homeostasis. In our previous work, we reported a novel multisystem disorder associated with the heterozygous TAB2 c.1398dup variant. Here, we dissect the functional effects of this variant in order to understand its molecular pathogenesis. We demonstrate that TAB2 c.1398dup considerably undergoes to nonsense-mediated messenger RNA decay and encodes a truncated protein that loses its ability to bind TAK1. We also show an alteration of the TAK1 autophosphorylation status and of selected downstream signaling pathways in patients' fibroblasts. Immunofluorescence analyses and ECM-related polymerase chain reaction-array panels highlight that patient fibroblasts display ECM disorganization and altered expression of selected ECM components and collagen-related pathways. In conclusion, we deeply dissect the molecular pathogenesis of the TAB2 c.1398dup variant and show that the resulting phenotype is well explained by TAB2 loss-of-function. Our data also offer initial insights on the ECM homeostasis impairment as a molecular mechanism probably underlying a multisystem disorder linked to TAB2.

Molecular insights in the pathogenesis of classical Ehlers-Danlos syndrome from transcriptome-wide expression profiling of patients' skin fibroblasts

Classical Ehlers-Danlos syndrome (cEDS) is a dominant inherited connective tissue disorder mainly caused by mutations in the COL5A1 and COL5A2 genes encoding type V collagen (COLLV), which is a fibrillar COLL widely distributed in a variety of connective tissues. cEDS patients suffer from skin hyperextensibility, abnormal wound healing/atrophic scars, and joint hypermobility. Most of the causative variants result in a non-functional COL5A1 allele and COLLV haploinsufficiency, whilst COL5A2 mutations affect its structural integrity. To shed light into disease mechanisms involved in cEDS, we performed gene expression profiling in skin fibroblasts from four patients harboring haploinsufficient and structural mutations in both disease genes. Transcriptome profiling revealed significant changes in the expression levels of different extracellular matrix (ECM)-related genes, such as SPP1, POSTN, EDIL3, IGFBP2, and C3, which encode both matricellular and soluble proteins that are mainly involved in cell proliferation and migration, and cutaneous wound healing. These gene expression changes are consistent with our previous protein findings on in vitro fibroblasts from other cEDS patients, which exhibited reduced migration and poor wound repair owing to COLLV disorganization, altered deposition of fibronectin into ECM, and an abnormal integrin pattern. Microarray analysis also indicated the decreased expression of DNAJB7, VIPAS39, CCPG1, ATG10, SVIP, which encode molecular chaperones facilitating protein folding, enzymes regulating post-Golgi COLLs processing, and proteins acting as cargo receptors required for endoplasmic reticulum (ER) proteostasis and implicated in the autophagy process. Patients’ cells also showed altered mRNA levels of many cell cycle regulating genes including CCNE2, KIF4A, MKI67, DTL, and DDIAS. Protein studies showed that aberrant COLLV expression causes the disassembly of itself and many structural ECM constituents including COLLI, COLLIII, fibronectin, and fibrillins. Our findings provide the first molecular evidence of significant gene expression changes in cEDS skin fibroblasts highlighting that defective ECM remodeling, ER homeostasis and autophagy might play a role in the pathogenesis of this connective tissue disorder.

Factors affecting quality of life in children and adolescents with hypermobile Ehlers-Danlos syndrome/hypermobility spectrum disorders

Hypermobile Ehlers-Danlos syndrome (hEDS) is a hereditary disorder of connective tissue, often presenting with complex symptoms can include chronic pain, fatigue, and dysautonomia. Factors influencing functional disability in the pediatric hEDS population are incompletely studied. This study's aims were to assess factors that affect quality of life in children and adolescents with hEDS. Individuals with hEDS between the ages 12-20 years and matched parents were recruited through retrospective chart review at two genetics clinics. Participants completed a questionnaire that included the Pediatric Quality of Life Inventory (PedsQL™), PedsQL Multidimentional Fatigue Scale, Functional Disability Inventory, Pain-Frequency-Severity-Duration Scale, the Brief Illness Perception Questionnaire, measures of anxiety and depression, and helpful interventions. Survey responses were completed for 47 children and adolescents with hEDS/hypermobility spectrum disorder (81% female, mean age 16 years), some by the affected individual, some by their parent, and some by both. Clinical data derived from chart review were compared statistically to survey responses. All outcomes correlated moderately to strongly with each other. Using multiple regression, general fatigue and pain scores were the best predictors of the PedsQL total score. Additionally, presence of any psychiatric diagnosis was correlated with a lower PedsQL score. Current management guidelines recommend early intervention to prevent disability from deconditioning; these results may help identify target interventions in this vulnerable population.

Updates in Clinical and Genetics Aspects of Hypermobile Ehlers Danlos Syndrome

Efforts on recognition, diagnosis, and management of the presumed, most common connective tissue disorder hypermobile Ehlers-Danlos syndrome have been an ongoing challenge, even decades after the description of this condition. A recent international consortium proposed a revised Ehlers-Danlos syndrome classification, an update much needed since Villefranche nosology, in 1998. Hypermobile Ehlers-Danlos syndrome is the only subtype in these groups of syndromes with no known genetic cause(s). This effort brought significant attention to this often underappreciated condition. This review provides an update of the clinical and genetic aspects of hypermobile Ehlers-Danlos syndrome for clinicians and researchers.

Multifaced Roles of the αvβ3 Integrin in Ehlers-Danlos and Arterial Tortuosity Syndromes' Dermal Fibroblasts

The αvβ3 integrin, an endothelial cells’ receptor-binding fibronectin (FN) in the extracellular matrix (ECM) of blood vessels, regulates ECM remodeling during migration, invasion, angiogenesis, wound healing and inflammation, and is also involved in the epithelial mesenchymal transition. In vitro-grown human control fibroblasts organize a fibrillar network of FN, which is preferentially bound on the entire cell surface to its canonical α5β1 integrin receptor, whereas the αvβ3 integrin is present only in rare patches in focal contacts. We report on the preferential recruitment of the αvβ3 integrin, due to the lack of FN–ECM and its canonical integrin receptor, in dermal fibroblasts from Ehlers–Danlos syndromes (EDS) and arterial tortuosity syndrome (ATS), which are rare multisystem connective tissue disorders. We review our previous findings that unraveled different biological mechanisms elicited by the αvβ3 integrin in fibroblasts derived from patients affected with classical (cEDS), vascular (vEDS), hypermobile EDS (hEDS), hypermobility spectrum disorders (HSD), and ATS. In cEDS and vEDS, respectively, due to defective type V and type III collagens, αvβ3 rescues patients’ fibroblasts from anoikis through a paxillin-p60Src-mediated cross-talk with the EGF receptor. In hEDS and HSD, without a defined molecular basis, the αvβ3 integrin transduces to the ILK-Snail1-axis inducing a fibroblast-to-myofibroblast-transition. In ATS cells, the deficiency of the dehydroascorbic acid transporter GLUT10 leads to redox imbalance, ECM disarray together with the activation of a non-canonical αvβ3 integrin-TGFBRII signaling, involving p125FAK/p60Src/p38MAPK. The characterization of these different biological functions triggered by αvβ3 provides insights into the multifaced nature of this integrin, at least in cultured dermal fibroblasts, offering future perspectives for research in this field.