scholarly journals The ABCC6 Transporter as a Paradigm for Networking from an Orphan Disease to Complex Disorders

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Eva Y. G. De Vilder ◽  
Mohammad Jakir Hosen ◽  
Olivier M. Vanakker
Keyword(s):  
Pseudoxanthoma Elasticum ◽  
Integrated System ◽  
Orphan Disease ◽  
Complex Disorders ◽  
Monogenic Disorders ◽  
Ectopic Mineralization ◽  
Monogenic Diseases ◽  
Network Approaches ◽  
Generation Sequencing

The knowledge on the genetic etiology of complex disorders largely results from the study of rare monogenic disorders. Often these common and rare diseases show phenotypic overlap, though monogenic diseases generally have a more extreme symptomatology.ABCC6, the gene responsible for pseudoxanthoma elasticum, an autosomal recessive ectopic mineralization disorder, can be considered a paradigm gene with relevance that reaches far beyond this enigmatic orphan disease. Indeed, common traits such as chronic kidney disease or cardiovascular disorders have been linked to theABCC6gene. While during the last decade the awareness of the wide ramifications ofABCC6has increased significantly, the gene itself and the transmembrane transporter it encodes have not unveiled all of the mysteries that surround them. To gain more insights, multiple approaches are being used including next-generation sequencing, computational methods, and various “omics” technologies. Much effort is made to place the vast amount of data that is gathered in an integrated system-biological network; the involvement ofABCC6in common disorders provides a good view on the wide implications and potential of such a network. In this review, we summarize the network approaches used to studyABCC6and the role of this gene in several complex diseases.

scholarly journals The Role of Vitamin K and Its Related Compounds in Mendelian and Acquired Ectopic Mineralization Disorders

2019 ◽  
Vol 20 (9) ◽  
pp. 2142
Author(s):  
Lukas Nollet ◽  
Matthias Van Gils ◽  
Shana Verschuere ◽  
Olivier Vanakker
Keyword(s):  
Vitamin K ◽  
Current Knowledge ◽  
Pseudoxanthoma Elasticum ◽  
Ectopic Calcification ◽  
Multifactorial Diseases ◽  
Multiple Organs ◽  
Keutel Syndrome ◽  
Ectopic Mineralization ◽  
Related Compounds

Ectopic mineralization disorders comprise a broad spectrum of inherited or acquired diseases characterized by aberrant deposition of calcium crystals in multiple organs, such as the skin, eyes, kidneys, and blood vessels. Although the precise mechanisms leading to ectopic calcification are still incompletely known to date, various molecular targets leading to a disturbed balance between pro- and anti-mineralizing pathways have been identified in recent years. Vitamin K and its related compounds, mainly those post-translationally activated by vitamin K-dependent carboxylation, may play an important role in the pathogenesis of ectopic mineralization as has been demonstrated in studies on rare Mendelian diseases, but also on highly prevalent disorders, like vascular calcification. This narrative review compiles and summarizes the current knowledge regarding the role of vitamin K, its metabolism, and associated compounds in the pathophysiology of both monogenic ectopic mineralization disorders, like pseudoxanthoma elasticum or Keutel syndrome, as well as acquired multifactorial diseases, like chronic kidney disease. Clinical and molecular aspects of the various disorders are discussed according to the state-of-the-art, followed by a comprehensive literature review regarding the role of vitamin K in molecular pathophysiology and as a therapeutic target in both human and animal models of ectopic mineralization disorders.

scholarly journals Dysregulation of gene expression in ABCC6 knockdown HepG2 cells

2014 ◽  
Vol 19 (4) ◽  
Author(s):  
Rocchina Miglionico ◽  
Maria Armentano ◽  
Monica Carmosino ◽  
Antonella Salvia ◽  
Flavia Cuviello ◽  
...  
Keyword(s):  
Hepg2 Cells ◽  
Autosomal Recessive ◽  
Pseudoxanthoma Elasticum ◽  
Arterial Calcification ◽  
Elastic Fibers ◽  
Ectopic Calcification ◽  
Ectopic Mineralization ◽  
Abcc6 Gene ◽  
Basolateral Plasma Membrane

AbstractABCC6 protein is an ATP-dependent transporter that is mainly found in the basolateral plasma membrane of hepatocytes. ABCC6 deficiency is the primary cause of several forms of ectopic mineralization syndrome. Mutations in the human ABCC6 gene cause pseudoxanthoma elasticum (PXE), an autosomal recessive disease characterized by ectopic calcification of the elastic fibers in dermal, ocular and vascular tissues. Mutations in the mouse ABCC6 gene were also associated with dystrophic cardiac calcification. Reduced levels of ABCC6 protein were found in a β-thalassemic mouse model. Moreover, some cases of generalized arterial calcification in infancy are due to ABCC6 mutations. In order to study the role of ABCC6 in the pathogenesis of ectopic mineralization, the expressions of genes involved in this process were evaluated in HepG2 cells upon stable knockdown of ABCC6 by small hairpin RNA (shRNA) technology. ABCC6 knockdown in HepG2 cells causes a significant upregulation of the genes promoting mineralization, such as TNAP, and a parallel downregulation of genes with anti-mineralization activity, such as NT5E, Fetuin A and Osteopontin. Although the absence of ABCC6 has been already associated with ectopic mineralization syndromes, this study is the first to show a direct relationship between reduced ABCC6 levels and the expression of pro-mineralization genes in hepatocytes.

scholarly journals ABCC6, Pyrophosphate and Ectopic Calcification: Therapeutic Solutions

2021 ◽  
Vol 22 (9) ◽  
pp. 4555
Author(s):  
Briana K. Shimada ◽  
Viola Pomozi ◽  
Janna Zoll ◽  
Sheree Kuo ◽  
Ludovic Martin ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Genetic Disorders ◽  
Pseudoxanthoma Elasticum ◽  
Arterial Calcification ◽  
Ectopic Calcification ◽  
Direct Inhibition ◽  
Inorganic Pyrophosphate ◽  
Cardiovascular Tissues ◽  
Ectopic Mineralization

Pathological (ectopic) mineralization of soft tissues occurs during aging, in several common conditions such as diabetes, hypercholesterolemia, and renal failure and in certain genetic disorders. Pseudoxanthoma elasticum (PXE), a multi-organ disease affecting dermal, ocular, and cardiovascular tissues, is a model for ectopic mineralization disorders. ABCC6 dysfunction is the primary cause of PXE, but also some cases of generalized arterial calcification of infancy (GACI). ABCC6 deficiency in mice underlies an inducible dystrophic cardiac calcification phenotype (DCC). These calcification diseases are part of a spectrum of mineralization disorders that also includes Calcification of Joints and Arteries (CALJA). Since the identification of ABCC6 as the “PXE gene” and the development of several animal models (mice, rat, and zebrafish), there has been significant progress in our understanding of the molecular genetics, the clinical phenotypes, and pathogenesis of these diseases, which share similarities with more common conditions with abnormal calcification. ABCC6 facilitates the cellular efflux of ATP, which is rapidly converted into inorganic pyrophosphate (PPi) and adenosine by the ectonucleotidases NPP1 and CD73 (NT5E). PPi is a potent endogenous inhibitor of calcification, whereas adenosine indirectly contributes to calcification inhibition by suppressing the synthesis of tissue non-specific alkaline phosphatase (TNAP). At present, therapies only exist to alleviate symptoms for both PXE and GACI; however, extensive studies have resulted in several novel approaches to treating PXE and GACI. This review seeks to summarize the role of ABCC6 in ectopic calcification in PXE and other calcification disorders, and discuss therapeutic strategies targeting various proteins in the pathway (ABCC6, NPP1, and TNAP) and direct inhibition of calcification via supplementation by various compounds.

scholarly journals The Integration of Psychosocial Care into National Dementia Strategies Across Europe: Evidence from the Skills in DEmentia Care (SiDECar) Project

2021 ◽  
Vol 18 (7) ◽  
pp. 3422
Author(s):  
Ilaria Chirico ◽  
Rabih Chattat ◽  
Vladimíra Dostálová ◽  
Pavla Povolná ◽  
Iva Holmerová ◽  
...  
Keyword(s):  
Content Analysis ◽  
Clinical Practice ◽  
Social Services ◽  
Psychosocial Care ◽  
Psychosocial Interventions ◽  
System Of Care ◽  
Dementia Care ◽  
Integrated System ◽  
Health And Social Services

There is evidence supporting the use of psychosocial interventions in dementia care. Due to the role of policy in clinical practice, the present study investigates whether and how the issue of psychosocial care and interventions has been addressed in the national dementia plans and strategies across Europe. A total of 26 national documents were found. They were analyzed by content analysis to identify the main pillars associated with the topic of psychosocial care and interventions. Specifically, three categories emerged: (1) Treatment, (2) Education, and (3) Research. The first one was further divided into three subcategories: (1) Person-centred conceptual framework, (2) Psychosocial interventions, and (3) Health and social services networks. Overall, the topic of psychosocial care and interventions has been addressed in all the country policies. However, the amount of information provided differs across the documents, with only the category of ‘Treatment’ covering all of them. Furthermore, on the basis of the existing policies, how the provision of psychosocial care and interventions would be enabled, and how it would be assessed are not fully apparent yet. Findings highlight the importance of policies based on a comprehensive and well-integrated system of care, where the issue of psychosocial care and interventions is fully embedded.

scholarly journals Disruption of Abcc6 Transporter in Zebrafish Causes Ocular Calcification and Cardiac Fibrosis

2020 ◽  
Vol 22 (1) ◽  
pp. 278
Author(s):  
Jianjian Sun ◽  
Peilu She ◽  
Xu Liu ◽  
Bangjun Gao ◽  
Daqin Jin ◽  
...  
Keyword(s):  
Vitamin K ◽  
Cardiac Fibrosis ◽  
Clinical Manifestations ◽  
Pseudoxanthoma Elasticum ◽  
Matrix Gla Protein ◽  
Ectopic Calcification ◽  
Transcription Activator ◽  
Multisystem Disorder ◽  
Ectopic Mineralization ◽  
Extensive Calcification

Pseudoxanthoma elasticum (PXE), caused by ABCC6/MRP6 mutation, is a heritable multisystem disorder in humans. The progressive clinical manifestations of PXE are accompanied by ectopic mineralization in various connective tissues. However, the pathomechanisms underlying the PXE multisystem disorder remains obscure, and effective treatment is currently available. In this study, we generated zebrafish abcc6a mutants using the transcription activator-like effector nuclease (TALEN) technique. In young adult zebrafish, abcc6a is expressed in the eyes, heart, intestine, and other tissues. abcc6a mutants exhibit extensive calcification in the ocular sclera and Bruch’s membrane, recapitulating part of the PXE manifestations. Mutations in abcc6a upregulate extracellular matrix (ECM) genes, leading to fibrotic heart with reduced cardiomyocyte number. We found that abcc6a mutation reduced levels of both vitamin K and pyrophosphate (PPi) in the serum and diverse tissues. Vitamin K administration increased the gamma-glutamyl carboxylated form of matrix gla protein (cMGP), alleviating ectopic calcification and fibrosis in vertebrae, eyes, and hearts. Our findings contribute to a comprehensive understanding of PXE pathophysiology from zebrafish models.

scholarly journals Polymorphism in BACH2 gene is a marker of polyglandular autoimmunity

Endocrine ◽  
2021 ◽  
Author(s):  
Marta Fichna ◽  
Magdalena Żurawek ◽  
Bartosz Słomiński ◽  
Marta Sumińska ◽  
Agata Czarnywojtek ◽  
...  
Keyword(s):  
Immune Cell ◽  
Premature Menopause ◽  
Complex Disorders ◽  
Increased Risk ◽  
Organ Specific ◽  
Autoimmune Conditions ◽  
Cell Balance ◽  
Type 3 ◽  
Polyglandular Autoimmunity

Abstract Purpose Genetically predisposed individuals may develop several autoimmune diseases—autoimmune polyendocrine syndromes (APS). APS types 2–4, are complex disorders, which combine various organ-specific autoimmune conditions. Recent reports support the considerable role of the BACH2 gene in immune cell differentiation and shifting the T-cell balance towards regulatory T-cells. BACH2 polymorphisms are associated with autoimmune disorders, including Addison’s disease (AD), Graves’ disease (GD), and probably type 1 diabetes (T1D). Our study was aimed to investigate the BACH2 variant, rs3757247, in endocrine autoimmunity in the Polish population. Methods The analysis comprised 346 individuals with APS, 387 with T1D only, and 568 controls. Genotyping was performed using TaqMan chemistry. Results APS type 2 was found in 219 individuals, type 3 in 102, and type 4 in 25 subjects. Overall, AD was diagnosed in 244 subjects, Hashimoto’s thyroiditis—in 238, T1D—in 127, GD—in 58, vitiligo and chronic gastritis each in 40 patients, celiac disease—in 28, premature menopause in 18, and alopecia in 4 patients. Minor T allele at rs3757247 was found in 56.4% APS vs. 44.1% control alleles (OR 1.59; 95%CI: 1.30–1.95, p < 0.0001). The distribution of genotypes revealed excess TT homozygotes in the APS cohort (33.2 vs. 20.1% in controls, p < 0.0001). The frequencies of rs3757247 alleles and genotypes in T1D patients did not present significant differences vs. controls (p-values > 0.05). Conclusions These results provide evidence of the association between BACH2 polymorphism and polyglandular autoimmunity. Since carriers of rs3757247 display increased risk for additional autoimmune conditions, this variant could identify individuals prone to develop APS.

scholarly journals Novel TTLL5 Variants Associated with Cone-Rod Dystrophy and Early-Onset Severe Retinal Dystrophy

2021 ◽  
Vol 22 (12) ◽  
pp. 6410
Author(s):  
Vasily Smirnov ◽  
Olivier Grunewald ◽  
Jean Muller ◽  
Christina Zeitz ◽  
Carolin D. Obermaier ◽  
...  
Keyword(s):  
Early Onset ◽  
Retinal Dystrophy ◽  
Copy Number Variants ◽  
Cone Dystrophy ◽  
The Novel ◽  
Targeted Next Generation Sequencing ◽  
Large Deletions ◽  
Gene Panels ◽  
Generation Sequencing

Variants of the TTLL5 gene, which encodes tubulin tyrosine ligase-like family member five, are a rare cause of cone dystrophy (COD) or cone-rod dystrophy (CORD). To date, only a few TTLL5 patients have been clinically and genetically described. In this study, we report five patients harbouring biallelic variants of TTLL5. Four adult patients presented either COD or CORD with onset in the late teenage years. The youngest patient had a phenotype of early onset severe retinal dystrophy (EOSRD). Genetic analysis was performed by targeted next generation sequencing of gene panels and assessment of copy number variants (CNV). We identified eight variants, of which six were novel, including two large multiexon deletions in patients with COD or CORD, while the EOSRD patient harboured the novel homozygous p.(Trp640*) variant and three distinct USH2A variants, which might explain the observed rod involvement. Our study highlights the role of TTLL5 in COD/CORD and the importance of large deletions. These findings suggest that COD or CORD patients lacking variants in known genes may harbour CNVs to be discovered in TTLL5, previously undetected by classical sequencing methods. In addition, variable phenotypes in TTLL5-associated patients might be due to the presence of additional gene defects.

scholarly journals Role of Probiotics and Their Metabolites in Inflammatory Bowel Diseases (IBDs)

2021 ◽  
Vol 12 (1) ◽  
pp. 56-66
Author(s):  
Toumi Ryma ◽  
Arezki Samer ◽  
Imene Soufli ◽  
Hayet Rafa ◽  
Chafia Touil-Boukoffa
Keyword(s):  
Ulcerative Colitis ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Clinical Symptoms ◽  
Therapeutic Potential ◽  
Short Chain Fatty Acids ◽  
Active Metabolites ◽  
Complex Disorders ◽  
Inflammatory Bowel

Inflammatory Bowel Disease (IBD) is a term used to describe a group of complex disorders of the gastrointestinal (GI) tract. IBDs include two main forms: Crohn’s Disease (CD) and Ulcerative Colitis (UC), which share similar clinical symptoms but differ in the anatomical distribution of the inflammatory lesions. The etiology of IBDs is undetermined. Several hypotheses suggest that Crohn’s Disease and Ulcerative Colitis result from an abnormal immune response against endogenous flora and luminal antigens in genetically susceptible individuals. While there is no cure for IBDs, most common treatments (medication and surgery) aim to reduce inflammation and help patients to achieve remission. There is growing evidence and focus on the prophylactic and therapeutic potential of probiotics in IBDs. Probiotics are live microorganisms that regulate the mucosal immune system, the gut microbiota and the production of active metabolites such as Short-Chain Fatty Acids (SCFAs). This review will focus on the role of intestinal dysbiosis in the immunopathogenesis of IBDs and understanding the health-promoting effects of probiotics and their metabolites.

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