| 1. |
- Andrae, Johanna, et al.
(författare)
-
A role for PDGF-C/PDGFR alpha signaling in the formation of the meningeal basement membranes surrounding the cerebral cortex
- 2016
-
Ingår i: Biology Open. - : The Company of Biologists. - 2046-6390. ; 5:4, s. 461-474
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor-C (PDGF-C) is one of three known ligands for the tyrosine kinase receptor PDGFR alpha. Analysis of Pdgfc null mice has demonstrated roles for PDGF-C in palate closure and the formation of cerebral ventricles, but redundancy with other PDGFR alpha ligands might obscure additional functions. In search of further developmental roles for PDGF-C, we generated mice that were double mutants for Pdgfc(-/-) and Pdgfra(GFP/+). These mice display a range of severe phenotypes including spina bifida, lung emphysema, abnormal meninges and neuronal over-migration in the cerebral cortex. We focused our analysis on the central nervous system (CNS), where PDGF-C was identified as a critical factor for the formation of meninges and assembly of the glia limitans basement membrane. We also present expression data on Pdgfa, Pdgfc and Pdgfra in the cerebral cortex and microarray data on cerebral meninges.
|
|
| 2. |
- Andrae, Johanna, et al.
(författare)
-
Characterization of Platelet-Derived Growth Factor-A Expression in Mouse Tissues Using a lacZ Knock-In Approach
- 2014
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8, s. e105477-
-
Tidskriftsartikel (refereegranskat)abstract
- Expression of the platelet-derived growth factor A-chain gene (Pdgfa) occurs widely in the developing mouse, where it is mainly localized to various epithelial and neuronal structures. Until now, in situ mRNA hybridization (ISH) has been the only reliable method to identify Pdgfa expression in tissue sections or whole mount preparations. Validated protocols for in situ detection of PDGF-A protein by immunohistochemistry is lacking. In particular, this has hampered understanding of Pdgfa expression pattern in adult tissues, where ISH is technically challenging. Here, we report a gene targeted mouse Pdgfa allele, Pdgfa(ex4COIN), which is a combined conditional knockout and reporter allele. Cre-mediated inversion of the COIN cassette inactivates Pdgfa coding while simultaneously activating a beta-galactosidase (lacZ) reporter under endogenous Pdgfa transcription control. The generated Pdgfa(ex4COIN-INV-lacZ) allele can next be used to identify cells carrying a Pdgfa null allele, as well as to map endogenous Pdgfa expression. We evaluated the Pdgfa(ex4COIN-INV-lacZ) allele as a reporter for endogenous Pdgfa expression patterns in mouse embryos and adults. We conclude that the expression pattern of Pdgfa(ex4COIN-INV-lacZ) recapitulates known expression patterns of Pdgfa. We also report on novel embryonic and adult Pdgfa expression patterns in the mouse and discuss their implications for Pdgfa physiology.
|
|
| 3. |
|
|
| 4. |
- Carvalho, Alexandra T. P., et al.
(författare)
-
Understanding the structural and dynamic consequences of DNA epigenetic modifications : Computational insights into cytosine methylation and hydroxymethylation
- 2014
-
Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 9:12, s. 1604-1612
-
Tidskriftsartikel (refereegranskat)abstract
- We report a series of molecular dynamics (MD) simulations of up to a microsecond combined simulation time designed to probe epigenetically modified DNA sequences. More specifically, by monitoring the effects of methylation and hydroxymethylation of cytosine in different DNA sequences, we show, for the first time, that DNA epigenetic modifications change the molecule's dynamical landscape, increasing the propensity of DNA toward different values of twist and/or roll/tilt angles (in relation to the unmodified DNA) at the modification sites. Moreover, both the extent and position of different modifications have significant effects on the amount of structural variation observed. We propose that these conformational differences, which are dependent on the sequence environment, can provide specificity for protein binding.
|
|
| 5. |
|
|
| 6. |
- Gouveia, Leonor, et al.
(författare)
-
Expression analysis of platelet-derived growth factor receptor alpha and its ligands in the developing mouse lung
- 2017
-
Ingår i: Physiological Reports. - : WILEY. - 2051-817X. ; 5:6
-
Tidskriftsartikel (refereegranskat)abstract
- Activation of the platelet-derived growth factor receptor-a (PDGFRa) signaling pathway is critically important during lung alveogenesis, the process in lung development during which alveoli are formed from the terminal alveolar sacs. Several studies have aimed to characterize the expression patterns of PDGFRa and its two ligands (PDGF-A and -C) in the lung, but published analyses have been limited to embryonic and/or perinatal time points, and no attempts have been made to characterize both receptor and ligand expression simultaneously. In this study, we present a detailed map of the expression patterns of PDGFRa, PDGF-A and PDGF-C during the entire period of lung development, that is, from early embryogenesis until adulthood. Three different reporter mice were analyzed (Pdgfa ex4-COIN-INV-lacZ, Pdgfc tm1Nagy, and Pdgfra tm11(EGFP) Sor), in which either lacZ or H2B-GFP were expressed under the respective promoter in gene-targeted alleles. A spatiotemporal dynamic expression was identified for both ligands and receptor. PDGF-A and PDGF-C were located to distinct populations of epithelial and smooth muscle cells, whereas PDGFRa expression was located to different mesenchymal cell populations. The detailed characterization of gene expression provides a comprehensive map of PDGFRa signaling in lung cells, opening up for a better understanding of the role of PDGF signaling during lung development.
|
|
| 7. |
- Gouveia, Leonor, et al.
(författare)
-
PDGF-A signaling is required for secondary alveolar septation and controls epithelial proliferation in the developing lung
- 2018
-
Ingår i: Development. - : The Company of Biologists. - 0950-1991 .- 1477-9129. ; 145:7
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor A (PDGF-A) signaling through PDGF receptor a is essential for alveogenesis. Previous studies have shown that Pdgfa(-/-) mouse lungs have enlarged alveolar airspace with absence of secondary septation, both distinctive features of bronchopulmonary dysplasia. To study how PDGF-A signaling is involved in alveogenesis, we generated lung-specific Pdgfa knockout mice (Pdgfa(fl/-); Spc-cre) and characterized their phenotype postnatally. Histological differences between mutant mice and littermate controls were visible after the onset of alveogenesis and maintained until adulthood. Additionally, we generated Pdgfa(fl/-); Spc-cre; Pdgfra(GFP/+) mice in which Pdgfra(+) cells exhibit nuclear GFP expression. In the absence of PDGF-A, the number of Pdgfra(GFP+) cells was significantly decreased. In addition, proliferation of Pdgfra(GFP+) cells was reduced. During alveogenesis, Pdgfra(GFP+) myofibroblasts failed to form the alpha-smooth muscle actin rings necessary for alveolar secondary septation. These results indicate that PDGF-A signaling is involved in myofibroblast proliferation and migration. In addition, we show an increase in both the number and proliferation of alveolar type II cells in Pdgfa(fl/-); Spc-cre lungs, suggesting that the increased alveolar airspace is not caused solely by deficient myofibroblast function.
|
|
| 8. |
- Gouveia, Leonor, 1990-
(författare)
-
The role of PDGF-A in lung development, injury and repair
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The developmental processes that take place during embryogenesis depend on a great number of proteins that are important for cell-to-cell communication. Platelet-derived growth factors are known to be important for epithelial-mesenchymal interactions during development and organogenesis. However, many details are still lacking regarding organ-specific PDGF expression patterns and detailed cellular functions. This thesis aims to better describe the contribution of PDGF-A signaling to lung developmental and injury processes.To study the cell-specific expression patterns of PDGF-A we generated a reporter mouse that show LacZ expression in all PDGF-A positive cells. This mouse model was used to characterize PDGF-A expression in embryonic and adult mouse tissues (paper I).With the use of three different reporter mice, we described the cell type specific expression patterns of PDGF-A, PDGF-C and PDGFRα in mouse lungs, from embryonic day 10.5 (E10.5) when development is initiated, until adulthood (Postnatal day 60) when the lung is fully mature (paper II).A lung-specific Pdgfa knockout mouse was generated and the impact of the deletion was studied during lung development and adulthood. Mice lacking Pdgfa expression in the lung survived until adulthood but exhibited abnormal alveolar development. This phenotype was caused by the inability of myofibroblasts to assemble alpha smooth muscle actin ring around the forming alveoli (paper III).To investigate if PDGF-A is involved in the injury response mechanisms of the adult lung, we generated inducible lung-specific Pdgfa knockout mice. In homeostasis, adult Pdgfa deletion did not result in any apparent phenotype, whereas after hyperoxia-induced lung injury, preliminary data show that mutant mice exhibit substantially more alveolar damage and immune cell infiltration (paper IV).In conclusion, this thesis reports novel insights into the expression and role of PDGF-A and PDGFRα for the lung, both in development and adulthood.
|
|
| 9. |
- Gouveia, Maria Leonor Seguardo, et al.
(författare)
-
Lung developmental arrest caused by PDGF-A deletion : consequences for the adult mouse lung
- 2020
-
Ingår i: American Journal of Physiology - Lung cellular and Molecular Physiology. - : AMER PHYSIOLOGICAL SOC. - 1040-0605 .- 1522-1504. ; 318:4, s. L831-L843
-
Tidskriftsartikel (refereegranskat)abstract
- PDGF-A is a key contributor to lung development in mice. Its expression is needed for secondary septation of the alveoli and deletion of the gene leads to abnormally enlarged alveolar air spaces in mice. In humans, the same phenotype is the hallmark of bronchopulmonary dysplasia (BPD), a disease that affects premature babies and may have long lasting consequences in adulthood. So far, the knowledge regarding adult effects of developmental arrest in the lung is limited. This is attributable to few follow-up studies of BPD survivors and lack of good experimental models that could help predict the outcomes of this early age disease for the adult individual. In this study, we used the constitutive lung-specific Pdgfa deletion mouse model to analyze the consequences of developmental lung defects in adult mice. We assessed lung morphology, physiology, cellular content, ECM composition and proteomics data in mature mice, that perinatally exhibited lungs with a BPD-like morphology. Histological and physiological analyses both revealed that enlarged alveolar air spaces remained until adulthood, resulting in higher lung compliance and higher respiratory volume in knockout mice. Still, no or only small differences were seen in cellular, ECM and protein content when comparing knockout and control mice. Taken together, our results indicate that Pdgfa deletion-induced lung developmental arrest has consequences for the adult lung at the morphological and functional level. In addition, these mice can reach adulthood with a BPD-like phenotype, which makes them a robust model to further investigate the pathophysiological progression of the disease and test putative regenerative therapies.
|
|
| 10. |
- He, Liqun, et al.
(författare)
-
Single-cell RNA sequencing of mouse brain and lung vascular and vessel-associated cell types
- 2018
-
Ingår i: Scientific Data. - : NATURE PUBLISHING GROUP. - 2052-4463. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- Vascular diseases are major causes of death, yet our understanding of the cellular constituents of blood vessels, including how differences in their gene expression profiles create diversity in vascular structure and function, is limited. In this paper, we describe a single-cell RNA sequencing (scRNA-seq) dataset that defines vascular and vessel-associated cell types and subtypes in mouse brain and lung. The dataset contains 3,436 single cell transcriptomes from mouse brain, which formed 15 distinct clusters corresponding to cell (sub) types, and another 1,504 single cell transcriptomes from mouse lung, which formed 17 cell clusters. In order to allow user-friendly access to our data, we constructed a searchable database (http://betsholtzlab.org/VascularSingleCells/database.html). Our dataset constitutes a comprehensive molecular atlas of vascular and vessel-associated cell types in the mouse brain and lung, and as such provides a strong foundation for future studies of vascular development and diseases.
|
|
