| 1. |
- Arregi, Igor, et al.
(författare)
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Retinol dehydrogenase-10 regulates pancreas organogenesis and endocrine cell differentiation via paracrine retinoic acid signaling
- 2016
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 157:12, s. 4615-4631
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Tidskriftsartikel (refereegranskat)abstract
- Vitamin A-derived retinoic acid (RA) signals are critical for the development of several organs, including the pancreas. However, the tissue-specific control of RA synthesis in organ and cell lineage development has only poorly been addressed in vivo. Here, we show that retinol dehydrogenase-10 (Rdh10), a key enzyme in embryonic RA production, has important functions in pancreas organogenesis and endocrine cell differentiation. Rdh10 was expressed in the developing pancreas epithelium and surrounding mesenchyme. Rdh10 null mutant mouse embryos exhibited dorsal pancreas agenesis and a hypoplastic ventral pancreas with retarded tubulogenesis and branching. Conditional disruption of Rdh10 from the endoderm caused increased mortality, reduced body weight, and lowered blood glucose levels after birth. Endodermal Rdh10 deficiency led to a smaller dorsal pancreas with a reduced density of early glucagonβ and insulinβ cells. During the secondary transition, the reduction of Neurogenin3β endocrine progenitors in the mutant dorsal pancreas accounted for fewer β-and α-cells. Changes in the expression of β-and α-cellspecific transcription factors indicated that Rdh10 might also participate in the terminal differentiation of endocrine cells. Together, our results highlight the importance of both mesenchymal andepithelialRdh10forpancreogenesisandthefirstwaveofendocrinecell differentiation.Wefurther propose a model in which the Rdh10-expressing exocrine tissue acts as an essential source ofRAsignals in the second wave of endocrine cell differentiation.
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| 2. |
- Gouignard, Nadège, et al.
(författare)
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Musculocontractural Ehlers-Danlos syndrome and neurocristopathies : Dermatan sulfate is required for Xenopus neural crest cells to migrate and adhere to fibronectin
- 2016
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Ingår i: Disease Models and Mechanisms. - : The Company of Biologists. - 1754-8403 .- 1754-8411. ; 9:6, s. 607-620
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Tidskriftsartikel (refereegranskat)abstract
- Of all live births with congenital anomalies, approximately one-third exhibit deformities ofthe head and face. Most craniofacial disorders are associated with defects in a migratory stem and progenitor cell population, which is designated the neural crest (NC). Musculocontractural Ehlers-Danlos syndrome (MCEDS) is a heritable connective tissue disorder with distinct craniofacial features; this syndrome comprises multiple congenital malformations that are caused bydysfunction ofdermatan sulfate (DS) biosynthetic enzymes, including DS epimerase-1 (DS-epi1; also known as DSE). Studies in mice have extended our understanding of DS-epi1 inconnective tissue maintenance; however, its role in fetal development is not understood. We demonstrate that DS-epi1isimportant for the generationofisolated iduronic acid residues in chondroitin sulfate (CS)/DS proteoglycans in early Xenopus embryos. The knockdown of DS-epi1 does not affect the formation of early NC progenitors; however, it impairs the correct activation of transcription factors involved in the epithelial-mesenchymal transition (EMT) and reduces the extent of NC cell migration, which leads to a decrease in NC-derived craniofacial skeleton, melanocytes and dorsal fin structures. Transplantation experiments demonstrate a tissue-autonomous role for DS-epi1 in cranial NC cell migration in vivo. Cranial NC explant and single-cell cultures indicate a requirement of DS-epi1 in cell adhesion, spreading and extension of polarized cell processes on fibronectin. Thus, our work indicates a functional link between DS and NC cell migration. We conclude that NC defects in the EMT and cell migration might account for the craniofacial anomalies and other congenital malformations in MCEDS, which might facilitate the diagnosis and development of therapies for this distressing condition. Moreover, the presented correlations between human DS-epi1 expression and gene sets of mesenchymal character, invasion and metastasis in neuroblastoma and malignant melanoma suggest an association between DS and NC-derived cancers.
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| 3. |
- Pera, Edgar, et al.
(författare)
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Aberrant neural crest development causes craniofacial and other malformations in an animal model of Musculocontractural Ehlers-Danlos syndrome.
- 2016
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Ingår i: Journal of Rare Diseases Research & Treatment. - 2572-9411. ; 1:3, s. 74-77
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Forskningsöversikt (refereegranskat)abstract
- Musculocontractural Ehlers-Danlos syndrome (MC-EDS) is a rare recessive disorder that is characterized by connective tissue fragility, distinct craniofacial features and congenital malformations. MC-EDS patients have defects in the enzymes dermatan sulfate epimerase-1 and dermatan 4-O-sulfotransferase-1, which are involved in the biosynthesis of iduronic acid in the chondroitin sulfate/dermatan sulfate (CS/DS) chains of proteoglycans (PGs). While the connective tissue defect is a result of disturbed collagen fibril assembly based on a decreased iduronic acid content of interacting CS/DS-PGs, the cause of the developmental malformations in MC-EDS is not well understood. This review focuses on a new role of CS/DS-PGs in the development of multipotent and highly migratory neural crest (NC) cells in the Xenopus embryo model of MC-EDS. Single iduronic acid residues in CS/DS-PGs are involved in the formation of NC-derived craniofacial structures by facilitating the migration and adhesion of NC cells to fibronectin. Our results suggest a defect in NC development as cause of the craniofacial and other congenital anomalies in MC-EDS patients, which might contribute to an improved diagnosis and etiology-based therapy.
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