| 1. |
- Bademci, Guney, et al.
(author)
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FOXF2 is required for cochlear development in humans and mice.
- 2019
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In: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 28:8, s. 1286-1297
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Journal article (peer-reviewed)abstract
- Molecular mechanisms governing the development of the human cochlea remain largely unknown. Through genome sequencing, we identified a homozygous FOXF2 variant c.325A>T (p.I109F) in a child with profound sensorineural hearing loss associated with incomplete partition type I anomaly of the cochlea. This variant is not found in public databases or in over 1,000 ethnicity-matched control individuals. I109 is a highly conserved residue in the forkhead box (Fox) domain of FOXF2, a member of the Fox protein family of transcription factors that regulate the expression of genes involved in embryogenic development as well as adult life. Our in vitro studies show that the half-life of mutant FOXF2 is reduced compared to that of wildtype. Foxf2 is expressed in the cochlea of developing and adult mice. The mouse knockout of Foxf2 shows shortened and malformed cochleae, in addition to altered shape of hair cells with innervation and planar cell polarity defects. Expressions of Eya1 and Pax3, genes essential for cochlear development, are reduced in the cochleae of Foxf2 knockout mice. We conclude that FOXF2 plays a major role in cochlear development and its dysfunction leads to sensorineural hearing loss and developmental anomalies of the cochlea in humans and mice.
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| 2. |
- Cansby, Emmelie, 1984, et al.
(author)
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Increased expression of STK25 leads to impaired glucose utilization and insulin sensitivity in mice challenged with a high-fat diet.
- 2013
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In: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - : Wiley. - 1530-6860. ; 27:9, s. 3660-3671
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Journal article (peer-reviewed)abstract
- Partial depletion of serine/threonine protein kinase 25 (STK25), a member of the Ste20 superfamily of kinases, increases lipid oxidation and glucose uptake in rodent myoblasts. Here we show that transgenic mice overexpressing STK25, when challenged with a high-fat diet, develop reduced glucose tolerance and insulin sensitivity compared to wild-type siblings, as evidenced by impairment in glucose and insulin tolerance tests as well as in euglycemic-hyperinsulinemic clamp studies. The fasting plasma insulin concentration was elevated in Stk25 transgenic mice compared to wild-type littermates (4.9±0.8 vs. 2.6±0.4 ng/ml after 17 wk on high-fat diet, P<0.05). Overexpression of STK25 decreased energy expenditure during the dark phase of observation (P<0.05), despite increased spontaneous activity. The oxidative capacity of skeletal muscle of transgenic carriers was reduced, as evidenced by altered expression of Cpt1, Acox1, and ACC. Hepatic triglycerides and glycogen were elevated (1.6- and 1.4-fold, respectively; P<0.05) and expression of key enzymes regulating lipogenesis (Fasn), glycogen synthesis (Gck), and gluconeogenesis (G6pc, Fbp1) was increased in the liver of the transgenic mice. Our findings suggest that overexpression of STK25 in conditions of excess dietary fuels associates with a shift in the metabolic balance in peripheral tissues from lipid oxidation to storage, leading to a systemic insulin resistance.-Cansby, E., Amrutkar, M., Mannerås Holm, L., Nerstedt, A., Reyahi, A., Stenfeldt, E., Borén, J., Carlsson, P., Smith, U., Zierath, J.R., Mahlapuu, M. Increased expression of STK25 leads to impaired glucose utilization and insulin sensitivity in mice challenged with a high-fat diet.
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| 3. |
- Cirnaru, Maria-Daniela, et al.
(author)
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Unbiased identification of novel transcription factors in striatal compartmentation and striosome maturation.
- 2021
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In: eLife. - 2050-084X. ; 10
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Journal article (peer-reviewed)abstract
- Many diseases are linked to dysregulation of the striatum. Striatal function depends on neuronal compartmentation into striosomes and matrix. Striatal projection neurons are GABAergic medium spiny neurons (MSNs), subtyped by selective expression of receptors, neuropeptides, and other gene families. Neurogenesis of the striosome and matrix occurs in separate waves, but the factors regulating compartmentation and neuronal differentiation are largely unidentified. We performed RNA- and ATAC-seq on sorted striosome and matrix cells at postnatal day 3, using the Nr4a1-EGFP striosome reporter mouse. Focusing on the striosome, we validated the localization and/or role of Irx1, Foxf2, Olig2, and Stat1/2 in the developing striosome and the in vivo enhancer function of a striosome-specific open chromatin region 4.4 Kb downstream of Olig2. These data provide novel tools to dissect and manipulate the networks regulating MSN compartmentation and differentiation, including in human iPSC-derived striatal neurons for disease modeling and drug discovery.
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| 4. |
- Gritli Linde, Amel, 1959, et al.
(author)
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Abnormal hair development and apparent follicular transformation to mammary gland in the absence of Hedgehog signaling
- 2007
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In: Developmental Cell. - : Elsevier BV. - 1534-5807. ; 12:1, s. 99-112
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Journal article (peer-reviewed)abstract
- Here, we show that removing the Shh receptor Smoothened from the skin epithelium results in a seemingly contradictory constellation of phenotypes including cellular disorganization, altered proliferation, and loss of hair follicle (HF) progenitors. We provide evidence that the lack of Smoothened in the epithelium results in excess Shh levels in the mesenchyme. Thus, the observed defects can be attributed not only to decreased epithelial Shh signaling, but increased mesenchymal Shh signalling. The latter contributes to exuberant HF induction, while the former depletes the resulting follicular stem cell niches. Two additional, unanticipated epithelial requirements for Shh relate to the robust acquisition of appropriate cell type identities: In the mutant mice, follicular outer root sheath takes on an epidermal character, and certain HF disappear altogether, having adopted a strikingly mammary gland-like fate. Our study uncovers a multifaceted function for Shh in sculpting and maintaining the integrity and identity of the developing HF.
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| 5. |
- Nawaz, Muhammad, et al.
(author)
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Lipid Nanoparticles Deliver the Therapeutic VEGFA mRNA In Vitro and In Vivo and Transform Extracellular Vesicles for Their Functional Extensions
- 2023
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In: Advanced Science. - : John Wiley & Sons. - 2198-3844. ; 10:12
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Journal article (peer-reviewed)abstract
- Lipid nanoparticles (LNPs) are currently used to transport functional mRNAs, such as COVID-19 mRNA vaccines. The delivery of angiogenic molecules, such as therapeutic VEGF-A mRNA, to ischemic tissues for producing new blood vessels is an emerging strategy for the treatment of cardiovascular diseases. Here, the authors deliver VEGF-A mRNA via LNPs and study stoichiometric quantification of their uptake kinetics and how the transport of exogenous LNP-mRNAs between cells is functionally extended by cells’ own vehicles called extracellular vesicles (EVs). The results show that cellular uptake of LNPs and their mRNA molecules occurs quickly, and that the translation of exogenously delivered mRNA begins immediately. Following the VEGF-A mRNA delivery to cells via LNPs, a fraction of internalized VEGF-A mRNA is secreted via EVs. The overexpressed VEGF-A mRNA is detected in EVs secreted from three different cell types. Additionally, RNA-Seq analysis reveals that as cells’ response to LNP-VEGF-A mRNA treatment, several overexpressed proangiogenic transcripts are packaged into EVs. EVs are further deployed to deliver VEGF-A mRNA in vitro and in vivo. Upon equal amount of VEGF-A mRNA delivery via three EV types or LNPs in vitro, EVs from cardiac progenitor cells are the most efficient in promoting angiogenesis per amount of VEGF-A protein produced. Intravenous administration of luciferase mRNA shows that EVs could distribute translatable mRNA to different organs with the highest amounts of luciferase detected in the liver. Direct injections of VEGF-A mRNA (via EVs or LNPs) into mice heart result in locally produced VEGF-A protein without spillover to liver and circulation. In addition, EVs from cardiac progenitor cells cause minimal production of inflammatory cytokines in cardiac tissue compared with all other treatment types. Collectively, the data demonstrate that LNPs transform EVs as functional extensions to distribute therapeutic mRNA between cells, where EVs deliver this mRNA differently than LNPs.
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| 6. |
- Nik, Ali Moussavi, et al.
(author)
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Foxf2 in Intestinal Fibroblasts Reduces Numbers of Lgr5(+) Stem Cells and Adenoma Formation by Inhibiting Wnt Signaling
- 2013
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In: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 144:5, s. 1001-1011
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Journal article (peer-reviewed)abstract
- Background & Aims The stem cell niche at the base of the intestinal crypts, as well as stemness and high clonogenicity in colon cancer cells, depend on Wnt signaling to β-catenin. Fibroblasts modulate the Wnt pathway in normal and neoplastic epithelial cells via unclear mechanisms. We investigated how in intestinal fibroblasts the forkhead transcription factor Foxf2 controls Wnt signaling to affect numbers of stem cells and formation and growth of adenomas in mice. Methods We created mice with different copy numbers of Foxf2 by generating Foxf2−/+ mice and a transgenic strain, Tg(FOXF2). Adenoma formation was investigated in ApcMin/+ mice, stem cells were counted in mice with the Lgr5–enhanced green fluorescent protein knock-in allele, proliferation was measured by incorporation of bromodeoxyuridine, Foxf2 and Sfrp1 were localized by immunohistochemistry, and signaling pathways were analyzed by quantitative polymerase chain reaction and immunoblot assays. Results Epithelial β-catenin was stabilized in Foxf2−/+ mice, resulting in increased number and size of adenomas. Tg(FOXF2) mice, however, were partially resistant to intestinal neoplasia and developed fewer and smaller adenomas; Foxf2−/+ mice developed 24-fold more tumors than Tg(FOXF2) mice. Epithelial cells of Foxf2−/+ mice also had higher numbers of Lgr5+ stem cells and greater amounts of crypt cell proliferation and expression of Myc (a target of Wnt signaling) than Tg(FOXF2) mice. Expression of Sfrp1, which encodes an extracellular inhibitor of Wnt, in fibroblasts increased with copy number of Foxf2. Conclusions Foxf2 is a fibroblast factor that inhibits paracrine Wnt signaling and restricts the crypt stem cell niche in intestines of mice. Loss of Foxf2 promotes adenoma formation and growth.
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| 7. |
- Nik, Ali Moussavi, et al.
(author)
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Foxf2 is required for secondary palate development and Tgfβ signaling in palatal shelf mesenchyme.
- 2016
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In: Developmental Biology. - : Elsevier BV. - 0012-1606 .- 1095-564X. ; 415:1, s. 14-23
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Journal article (peer-reviewed)abstract
- The secondary palate separates the oral from the nasal cavity and its closure during embryonic development is sensitive to genetic perturbations. Mice with deleted Foxf2, encoding a forkhead transcription factor, are born with cleft palate, and an abnormal tongue morphology has been proposed as the underlying cause. Here, we show that Foxf2(-/-) maxillary explants cultured in vitro, in the absence of tongue and mandible, failed to close the secondary palate. Proliferation and collagen content were decreased in Foxf2(-/-) palatal shelf mesenchyme. Phosphorylation of Smad2/3 was reduced in mutant palatal shelf, diagnostic of attenuated canonical Tgfβ signaling, whereas phosphorylation of p38 was increased. The amount of Tgfβ2 protein was diminished, whereas the Tgfb2 mRNA level was unaltered. Expression of several genes encoding extracellular proteins important for Tgfβ signaling were reduced in Foxf2(-)(/)(-) palatal shelves: a fibronectin splice-isoform essential for formation of extracellular Tgfβ latency complexes; Tgfbr3 - or betaglycan - which acts as a co-receptor and an extracellular reservoir of Tgfβ; and integrins αV and β1, which are both Tgfβ targets and required for activation of latent Tgfβ. Decreased proliferation and reduced extracellular matrix content are consistent with diminished Tgfβ signaling. We therefore propose that gene expression changes in palatal shelf mesenchyme that lead to reduced Tgfβ signaling contribute to cleft palate in Foxf2(-)(/)(-) mice.
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| 8. |
- Reyahi, Azadeh, et al.
(author)
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An IKBKE variant conferring functional cGAS/STING pathway deficiency and susceptibility to recurrent HSV-2 meningitis.
- 2023
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In: JCI insight. - 2379-3708. ; 8:21
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Journal article (peer-reviewed)abstract
- The mechanisms underlying susceptibility to recurrent herpes simplex virus type 2 (HSV-2) meningitis remain incompletely understood. In a patient experiencing multiple episodes of HSV-2 meningitis, we identified a monoallelic variant in the IKBKE gene, which encodes the IKKε kinase involved in induction of antiviral IFN genes. Patient cells displayed impaired induction of IFN-β1 (IFNB1) expression upon infection with HSV-2 or stimulation with double-stranded DNA (dsDNA) and failed to induce phosphorylation of STING, an activation marker of the DNA-sensing cyclic GMP-AMP synthase/stimulator of IFN genes (cGAS/STING) pathway. The patient allele encoded a truncated IKKε protein with loss of kinase activity and also capable of exerting dominant-negative activity. In stem cell-derived microglia, HSV-2-induced expression of IFNB1 was dependent on cGAS, TANK binding kinase 1 (TBK1), and IKBKE, but not TLR3, and supernatants from HSV-2-treated microglia exerted IKBKE-dependent type I IFN-mediated antiviral activity upon neurons. Reintroducing wild-type IKBKE into patient cells rescued IFNB1 induction following treatment with HSV-2 or dsDNA and restored antiviral activity. Collectively, we identify IKKε to be important for protection against HSV-2 meningitis and suggest a nonredundant role for the cGAS/STING pathway in human antiviral immunity.
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| 9. |
- Reyahi, Azadeh, et al.
(author)
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Foxf2 Is Required for Brain Pericyte Differentiation and Development and Maintenance of the Blood-Brain Barrier
- 2015
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In: Developmental Cell. - : Elsevier BV. - 1534-5807 .- 1878-1551. ; 34:1, s. 19-32
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Journal article (peer-reviewed)abstract
- Pericytes are critical for cerebrovascular maturation and development of the blood-brain barrier (BBB), but their role in maintenance of the adult BBB, and how CNS pericytes differ from those of other tissues, is less well understood. We show that the forkhead transcription factor Foxf2 is specifically expressed in pericytes of the brain and that Foxf2(-/-) embryos develop intracranial hemorrhage, perivascular edema, thinning of the vascular basal lamina, an increase of luminal endothelial caveolae, and a leaky BBB. Foxf2(-/-) brain pericytes were more numerous, proliferated faster, and expressed significantly less Pdgfr beta. Tgf beta-Smad2/3 signaling was attenuated, whereas phosphorylation of Smad1/5 and p38 were enhanced. Tgf beta pathway components, including Tgf beta 2, Tgf beta r2, Alk5, and integrins alpha(V)beta(8), were reduced. Foxf2 inactivation in adults resulted in BBB breakdown, endothelial thickening, and increased trans-endothelial vesicular transport. On the basis of these results, FOXF2 emerges as an interesting candidate locus for stroke susceptibility in humans.
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| 10. |
- Reyahi, Azadeh
(author)
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The Foxf2 gene in development and disease
- 2015
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Doctoral thesis (other academic/artistic)abstract
- The Foxf2 gene in development and disease Azadeh Reyahi Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE 405 30, Göteborg, Sweden Abstract In this thesis I present our recent data on the involvement and the mechanism of action of the forkhead transcription factor Foxf2 in development of the brain microvasculature, formation of the blood-brain barrier, control of the intestinal stem cell niche, and fusion of the secondary palate. The potential clinical signifi- cance of these findings is strengthened by a correlation between Foxf2 expres- sion and intestinal adenoma formation, and by association between genetic vari- ants in human FOXF2 and incident stroke. We showed that Foxf2 is expressed in brain pericytes, but not in mural cells of other organs. Foxf2 null mutants have a defective brain vasculature and suffer from intracranial hemorrhage and a leaky blood-brain barrier with increased endothelial vesicular trans-cytosis. Foxf2-/- brain pericytes have diminished Pdg- frβ expression, and the cerebral vasculature a reduced activity of the Tgfβ –Alk5– Smad2/3 signaling pathway, associated with decreased expression of integrins, Tgfb2, Tgfbr2, Alk5 and other pathway components. In a large GWAS performed by an international consortium, we identified a genome-wide significant association of common variants near FOXF2 with risk of stroke. Conditional knockout mice, in which Foxf2 was deleted in healthy adults, developed clinical signs of stroke and exhibited cerebral ischemia, reactive glio- sis and microhemorrhage. The animal model results thus corroborate the human genetic association and identifies FOXF2 as a novel risk locus for stroke. In the intestine we showed that Foxf2 is expressed by subepithelial fibroblasts and restricts the size of the stem cell niche, and thereby the number and prolif- eration of Lgr5+ stem cells. Foxf2 is a target of epithelial hedegehog signaling and inhibits the Wnt pathway by increasing the expression of the extracellular Wnt inhibitor Sfrp1. As a consequence, reduced Foxf2 expression significantly in- creases both initiation and growth of intestinal tumors. Reduced proliferation and decreased extracellular matrix production in the neural crest-derived mesenchyme of the palatal shelves was found to be respon- sible for the cleft palate phenotype in Foxf2 null mutants. Mechanistically, the defect is associated with reduced canonical Tgfβ signaling and integrin expres- sion. The Tgfb2 mRNA level was not affected, but the amount of Tgfβ2 protein was significantly decreased in mutant palatal shelf mesenchyme.
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