Four decades in the making: Collagen III and mechanisms of vascular Ehlers Danlos Syndrome

Placenta accreta spectrum disorder at single-cell resolution: a loss of boundary limits in the decidua and endothelium

BACKGROUND

Placenta accreta spectrum disorders are associated with severe maternal morbidity and mortality. Placenta accreta spectrum disorders involve excessive adherence of the placenta preventing separation at birth. Traditionally, this condition has been attributed to excessive trophoblast invasion; however, an alternative view is a fundamental defect in decidual biology.

OBJECTIVE

This study aimed to gain insights into the understanding of placenta accreta spectrum disorder by using single-cell and spatially resolved transcriptomics to characterize cellular heterogeneity at the maternal-fetal interface in placenta accreta spectrum disorders.

STUDY DESIGN

To assess cellular heterogeneity and the function of cell types, single-cell RNA sequencing and spatially resolved transcriptomics were used. A total of 12 placentas were included, 6 placentas with placenta accreta spectrum disorder and 6 controls. For each placenta with placenta accreta spectrum disorder, multiple biopsies were taken at the following sites: placenta accreta spectrum adherent and nonadherent sites in the same placenta. Of note, 2 platforms were used to generate libraries: the 10× Chromium and NanoString GeoMX Digital Spatial Profiler for single-cell and spatially resolved transcriptomes, respectively. Differential gene expression analysis was performed using a suite of bioinformatic tools (Seurat and GeoMxTools R packages). Correction for multiple testing was performed using Clipper. In situ hybridization was performed with RNAscope, and immunohistochemistry was used to assess protein expression.

RESULTS

In creating a placenta accreta cell atlas, there were dramatic difference in the transcriptional profile by site of biopsy between placenta accreta spectrum and controls. Most of the differences were noted at the site of adherence; however, differences existed within the placenta between the adherent and nonadherent site of the same placenta in placenta accreta. Among all cell types, the endothelial-stromal populations exhibited the greatest difference in gene expression, driven by changes in collagen genes, namely collagen type III alpha 1 chain (COL3A1), growth factors, epidermal growth factor-like protein 6 (EGFL6), and hepatocyte growth factor (HGF), and angiogenesis-related genes, namely delta-like noncanonical Notch ligand 1 (DLK1) and platelet endothelial cell adhesion molecule-1 (PECAM1). Intraplacental tropism (adherent versus non-adherent sites in the same placenta) was driven by differences in endothelial-stromal cells with notable differences in bone morphogenic protein 5 (BMP5) and osteopontin (SPP1) in the adherent vs nonadherent site of placenta accreta spectrum.

CONCLUSION

Placenta accreta spectrum disorders were characterized at single-cell resolution to gain insight into the pathophysiology of the disease. An atlas of the placenta at single cell resolution in accreta allows for understanding in the biology of the intimate maternal and fetal interaction. The contributions of stromal and endothelial cells were demonstrated through alterations in the extracellular matrix, growth factors, and angiogenesis. Transcriptional and protein changes in the stroma of placenta accreta spectrum shift the etiologic explanation away from "invasive trophoblast" to "loss of boundary limits" in the decidua. Gene targets identified in this study may be used to refine diagnostic assays in early pregnancy, track disease progression over time, and inform therapeutic discoveries.

Dysregulation of extracellular matrix and Lysyl Oxidase in Ehlers-Danlos syndrome type IV skin fibroblasts

BACKGROUND

Ehlers-Danlos syndrome Type IV (aka Vascular Ehlers Danlos, or vEDS) is a dominantly inherited mutation in the Collagen 3A1 gene (COL3A1). The disease is characterized by tissue friability and age-related susceptibility to arterial aneurysm, dissection and rupture as well as uterine and bowl tears. These clinical manifestations result in major surgical intervention and decreased life expectancy. Understanding how mutations in COL3A1 impact the structure and function of the extracellular matrix (ECM) is important to managing the disease and finding treatments.

RESULTS

Skin fibroblasts from vEDS subjects heterozygous for the p.G588S pathogenic variant in the COL3A1 gene and a normal individual were cultured and studied. Proteomics analysis identified dozens of upregulated proteins related to extracellular matrix dysregulation that is characteristic of fibrosis. Gene expression libraries from cultured primary fibroblasts were screened for messenger RNA (mRNA) markers of ECM degradation. The proteomics and targeted gene expression array results were largely consistent with dysregulation of the extracellular matrix in vEDS. The data show upregulation of multiple Collagen proteins and genes, other ECM components, and enzymes related to ECM processing and turn-over. vEDS fibroblasts expressed significantly more cross linked C-Telopeptide of Collagen III (CTXIII) than normal fibroblasts, indicative of Collagen III degradation and turn-over. Further, the expression and activity of Lysyl Oxidase (LOX), an enzyme that initiates covalent cross-linking of soluble collagen and elastin into protease resistant fibers, is elevated in vEDS fibroblasts compared to normal fibroblasts.

CONCLUSION

Together, these findings suggest dysregulated ECM deposition and processing, reminiscent of a state of fibrosis. Therapeutics that target the dysregulated ECM proteins or help replace damaged tissue may improve clinical outcomes.

Blockage of VEGF function by bevacizumab alleviates early-stage cerebrovascular dysfunction and improves cognitive function in a mouse model of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder and the predominant type of dementia worldwide. It is characterized by the progressive and irreversible decline of cognitive functions. In addition to the pathological beta-amyloid (Aβ) deposition, glial activation, and neuronal injury in the postmortem brains of AD patients, increasing evidence suggests that the often overlooked vascular dysfunction is an important early event in AD pathophysiology. Vascular endothelial growth factor (VEGF) plays a critical role in regulating physiological functions and pathological changes in blood vessels, but whether VEGF is involved in the early stage of vascular pathology in AD remains unclear.

METHODS

We used an antiangiogenic agent for clinical cancer treatment, the humanized monoclonal anti-VEGF antibody bevacizumab, to block VEGF binding to its receptors in the 5×FAD mouse model at an early age. After treatment, memory performance was evaluated by a novel object recognition test, and cerebral vascular permeability and perfusion were examined by an Evans blue assay and blood flow scanning imaging analysis. Immunofluorescence staining was used to measure glial activation and Aβ deposits. VEGF and its receptors were analyzed by enzyme-linked immunosorbent assay and immunoblotting. RNA sequencing was performed to elucidate bevacizumab-associated transcriptional signatures in the hippocampus of 5×FAD mice.

RESULTS

Bevacizumab treatment administered from 4 months of age dramatically improved cerebrovascular functions, reduced glial activation, and restored long-term memory in both sexes of 5×FAD mice. Notably, a sex-specific change in different VEGF receptors was identified in the cortex and hippocampus of 5×FAD mice. Soluble VEGFR1 was decreased in female mice, while full-length VEGFR2 was increased in male mice. Bevacizumab treatment reversed the altered expression of receptors to be comparable to the level in the wild-type mice. Gene Set Enrichment Analysis of transcriptomic changes revealed that bevacizumab effectively reversed the changes in the gene sets associated with blood-brain barrier integrity and vascular smooth muscle contraction in 5×FAD mice.

CONCLUSIONS

Our study demonstrated the mechanistic roles of VEGF at the early stage of amyloidopathy and the protective effects of bevacizumab on cerebrovascular function and memory performance in 5×FAD mice. These findings also suggest the therapeutic potential of bevacizumab for the early intervention of AD.

Deciphering disease signatures and molecular targets in vascular Ehlers-Danlos syndrome through transcriptome and miRNome sequencing of dermal fibroblasts

Vascular Ehlers-Danlos syndrome (vEDS) is a severe connective tissue disorder caused by dominant mutations in the COL3A1 gene encoding type III collagen (COLLIII). COLLIII is primarily found in blood vessels and hollow organs, and its deficiency leads to soft connective tissues fragility, resulting in life-threatening arterial and organ ruptures. There are no current targeted therapies available. Although the disease usually results from COLLIII misfolding due to triple helix structure disruption, the underlying pathomechanisms are largely unknown. To address this knowledge gap, we performed a comprehensive transcriptome analysis using RNA- and miRNA-seq on a large cohort of dermal fibroblasts from vEDS patients and healthy donors. Our investigation revealed an intricate interplay between proteostasis abnormalities, inefficient endoplasmic reticulum stress response, and compromised autophagy, which may significantly impact the molecular pathology. We also present the first detailed miRNAs expression profile in patient cells, demonstrating that several aberrantly expressed miRNAs can disrupt critical cellular functions involved in vEDS pathophysiology, such as autophagy, proteostasis, and mTOR signaling. Target prediction and regulatory networks analyses suggested potential interactions among miRNAs, lncRNAs, and candidate target genes linked to extracellular matrix organization and autophagy-lysosome pathway. Our results highlight the importance of understanding the functional role of ncRNAs in vEDS pathogenesis, shedding light on possible miRNAs and lncRNAs signatures and their functional implications for dysregulated pathways related to disease. Deciphering this complex molecular network of RNA interactions may yield additional evidence for potential disease biomolecules and targets, assisting in the design of effective patient treatment strategies.

Local Net Charge State of Collagen Triple Helix Is a Determinant of FKBP22 Binding to Collagen III

Mutations in the FKBP14 gene encoding the endoplasmic reticulum resident collagen-related proline isomerase FK506 binding protein 22 kDa (FKBP22) result in kyphoscoliotic Ehlers-Danlos Syndrome (EDS), which is characterized by a broad phenotypic outcome. A plausible explanation for this outcome is that FKBP22 participates in the biosynthesis of subsets of collagen types: FKBP22 selectively binds to collagens III, IV, VI, and X, but not to collagens I, II, V, and XI. However, these binding mechanisms have never been explored, and they may underpin EDS subtype heterogeneity. Here, we used collagen Toolkit peptide libraries to investigate binding specificity. We observed that FKBP22 binding was distributed along the collagen helix. Further, it (1) was higher on collagen III than collagen II peptides and it (2) was correlated with a positive peptide charge. These findings begin to elucidate the mechanism by which FKBP22 interacts with collagen.

Bowel Perforation in Vascular Ehlers-Danlos Syndrome: Case Report and Comprehensive Review

INTRODUCTION

Ehlers-Danlos syndromes (EDS) comprise a rare variety of genetic disorders, affecting all types of collagen. Herein, we describe a case of the vascular type of EDS, with coexisting segmental absence of intestinal musculature, while simultaneously performing a narrative review of the existing literature.

CASE PRESENTATION

A 23-year-old male patient with a history of multiple abdominal operations due to recurrent bowel perforations and the presence of a high-output enterocutaneous fistula was admitted to our surgical department for further evaluation and treatment. After detailed diagnostic testing, the diagnosis of vascular-type EDS (vEDS) was made and a conservative therapeutic approach was adopted. In addition, a comprehensive review of the international literature was carried out by applying the appropriate search terms.

RESULTS

The diagnosis of vEDS was molecularly confirmed by means of genetic testing. The patient was treated conservatively, with parenteral nutrition and supportive methods. Thirty-four cases of bowel perforation in vEDS have been reported so far. Interestingly, this case is the second one ever to report co-existence of vEDS with Segmental Absence of Intestinal Musculature.

CONCLUSIONS

Establishing the diagnosis of vEDS promptly is of vital significance in order to ensure that patients receive appropriate treatment. Due to initial non-specific clinical presentation, EDS should always be included in the differential diagnoses of young patients with unexplained perforations of the gastrointestinal tract.

Case report: Complex arterial findings in vascular ehlers-danlos syndrome with a novel COL3A1 variant and death at young age

Vascular Ehlers-Danlos syndrome (vEDS) is a genetic disease caused by a pathogenic mutation in the COL3A1 gene. Despite its severe course, the rarity and extreme clinical variability of the disease can pose significant obstacles to a timely diagnosis. Early and accurate diagnosis may lead to improved patient outcomes by providing access to targeted pharmacological treatments like celiprolol and enhancing the management of vEDS-related complications. Herein, we report a patient harboring a novel de novo COL3A1 missense variant, in which the diagnosis was only possible belatedly due to delayed referral for genetic evaluation. The patient developed pulmonary complications, aneurysms, and vascular malformations, and died at the age of 26 years due to massive pulmonary bleeding.

Adjustment to disease and quality of life in people with vascular Ehlers-Danlos and Loeys-Dietz syndromes: A mixed-method study

Background

Vascular Ehlers-Danlos (vEDS) and Loeys-Dietz syndromes (LDS) are hereditary disorders of connective tissue having severe vascular complications (HDCTv) which lead to an increased risk of premature death. Little is known about the impact of the disease in patient's daily life.

Method

Sixteen HDCTv patients (vEDS = 9 and LDS = 7), 16 age and sex-matched hypermobile Ehlers-Danlos syndrome patients (hEDS) and 18 healthy subjects (HS), responded to self-questionnaires assessing psychosocial adjustment, quality of life (QoL), anxiety, depression, pain, fatigue and sleep problems. Patients with HDCTv were also interviewed in order to explore qualitatively their experience with the disease.

Results

Compared with HS, patients with HDCTv scored significantly higher on anxiety, depression, fatigue, sleep problems, and lower on QoL. Most HDCTv patients (93.8%) have optimal psychosocial adjustment. In addition, HDCTv patients scored higher on QoL and psychosocial adjustment, but lower in pain, fatigue, sleep problems, and depressive symptoms than hEDS patients. Four main themes were identified in qualitative analyses: living with HDCTv, knowledge/ignorance of the disease, health behaviors/self-care and coping strategies.

Conclusion

Our results suggest that despite the negative impact of HDCTv on the patients' daily lives, overall, they present an optimal disease adjustment which points to appropriate coping strategies. More research in psychosocial aspects of people with these rare diseases are needed to confirm these results and better understand their needs.

The dysmorphic phenotype in vascular Ehlers Danlos syndrome

The Ehlers Danlos syndromes are identified by their connective tissue features and are not rich in dysmorphic handles. Vascular Ehlers Danlos syndrome (vEDS) however, is characterised by a recognisable phenotypic constellation of internal and external dysmorphology. This review charts the paediatric and adult phenotypes of vEDS due primarily to COL3A1 gene variants and the potential recognition of some other EDS subtypes, including COL1A1 and COL25A1 that can present with vEDS-like features, with certain dysmorphic handles as clues to the diagnosis and the adjunct of gene testing in patients presenting with vEDS features.

Lysyl hydroxylase 3-mediated post-translational modifications are required for proper biosynthesis of collagen α1α1α2(IV)

Collagens are the most abundant proteins in the body and among the most biosynthetically complex. A molecular ensemble of over 20 endoplasmic reticulum resident proteins participates in collagen biosynthesis and contributes to heterogeneous post-translational modifications. Pathogenic variants in genes encoding collagens cause connective tissue disorders, including osteogenesis imperfecta, Ehlers-Danlos syndrome, and Gould syndrome (caused by mutations in COL4A1 and COL4A2), and pathogenic variants in genes encoding proteins required for collagen biosynthesis can cause similar but overlapping clinical phenotypes. Notably, pathogenic variants in lysyl hydroxylase 3 (LH3) cause a multisystem connective tissue disorder that exhibits pathophysiological features of collagen-related disorders. LH3 is a multifunctional collagen-modifying enzyme; however, its precise role(s) and substrate specificity during collagen biosynthesis has not been defined. To address this critical gap in knowledge, we generated LH3 KO cells and performed detailed quantitative and molecular analyses of collagen substrates. We found that LH3 deficiency severely impaired secretion of collagen α1α1α2(IV) but not collagens α1α1α2(I) or α1α1α1(III). Amino acid analysis revealed that LH3 is a selective LH for collagen α1α1α2(IV) but a general glucosyltransferase for collagens α1α1α2(IV), α1α1α2(I), and α1α1α1(III). Importantly, we identified rare variants that are predicted to be pathogenic in the gene encoding LH3 in two of 113 fetuses with intracranial hemorrhage-a cardinal feature of Gould syndrome. Collectively, our findings highlight a critical role of LH3 in α1α1α2(IV) biosynthesis and suggest that LH3 pathogenic variants might contribute to Gould syndrome.