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Saroya GA, Siismets E, Hu M, Panaretos C, Rice A, Reynolds K, Zhou CJ, Kaartinen V. Canonical Wnt signaling is not required for Tgfb3 expression in the basal medial edge epithelium during palatogenesis. Front Physiol 2023; 14:704406. [PMID: 37250135 PMCID: PMC10213314 DOI: 10.3389/fphys.2023.704406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 04/28/2023] [Indexed: 05/31/2023] Open
Abstract
The secondary palate forms from two lateral primordia called the palatal shelves which form a contact in the midline, become adherent at the fusing interface (medial edge epithelia, MEE) and subsequently fuse. The gene encoding transforming growth factor-ß3 (Tgfb3) is strongly and specifically expressed in MEE cells. Our previous study suggested that Tgfb3 expression is controlled via upstream cis-regulatory elements in and around the neighboring Ift43 gene. Another study suggested that the canonical Wnt signaling via ß-Catenin is responsible for the MEE-specific Tgfb3 gene expression, since deletion of the Ctnnb1 gene by a commonly used Keratin 14-Cre (K14Cre) mouse line almost completely abolished Tgfb3 expression in the MEE resulting in cleft palate. Here, we wanted to analyze whether Tcf/Lef consensus binding sites located in the previously identified regions of the Ift43 gene are responsible for the spatiotemporal control of Tgfb3 expression during palatogenesis. We show that contrary to the previous report, deletion of the Ctnnb1 gene in basal MEE cells by the K14Cre driver (the same K14Cre mouse line was used as in the previous study referenced above) does not affect the MEE-specific Tgfb3 expression or TGFß3-dependent palatal epithelial fusion. All mutant embryos showed a lack of palatal rugae accompanied by other craniofacial defects, e.g., a narrow snout and a small upper lip, while only a small subset (<5%) of Ctnnb1 mutants displayed a cleft palate. Moreover, the K14Cre:Ctnnb1 embryos showed reduced levels and altered patterns of Shh expression. Our present data imply that epithelial ß-catenin may not be required for MEE-specific Tgfb3 expression or palatal epithelial fusion.
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Affiliation(s)
- Ghazi-Abdullah Saroya
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, United States
| | - Erica Siismets
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, United States
- Oral Health Sciences PhD Program, University of Michigan School of Dentistry, Ann Arbor, MI, United States
| | - Max Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, United States
- College of Literature, Sciences and the Arts, University of Michigan, Ann Arbor, MI, United States
| | - Christopher Panaretos
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, United States
| | - Adam Rice
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, United States
| | - Kurt Reynolds
- School of Medicine, Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California, University of California at Davis, Sacramento, CA, United States
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California at Davis, Sacramento, CA, United States
| | - Chengji J. Zhou
- School of Medicine, Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California, University of California at Davis, Sacramento, CA, United States
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California at Davis, Sacramento, CA, United States
| | - Vesa Kaartinen
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, United States
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Ye EA, Liu L, Steinle JJ. miR-15a/16 inhibits TGF-beta3/VEGF signaling and increases retinal endothelial cell barrier proteins. Vision Res 2017; 139:23-29. [PMID: 28774775 DOI: 10.1016/j.visres.2017.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/12/2017] [Accepted: 07/18/2017] [Indexed: 01/28/2023]
Abstract
Hyperglycemia is a significant risk factor for diabetic retinopathy and induces multiple biochemical changes, including inflammation and endothelial dysfunction in the retina. Alterations in microRNA expression have been implicated in the pathological responses of diabetic retinopathy and the manipulation of microRNA may provide powerful strategy for therapeutics. Among the predicted targets of miR-15a and -16 are TGF-beta3, SMAD2/3, and VEGF, all of which are known to play a role in vascular endothelial functions. The purpose of this study was to investigate the hypothesis that miR-15a/16 inhibits TGF-beta3/VEGF signaling to maintain retinal endothelial cell barrier protein levels. Human primary retinal endothelial cells (REC) were maintained in normal (5mM) glucose or transferred to high glucose medium (25mM) for 3days. REC were transfected with miRNA mimics (hsa-miR-15a-5p and -16-5p). Retinal lysates from miR-15a-transgenic mice were also analyzed. We demonstrated that overexpression of miR-15a/16 resulted in decreased TGF-beta3 signaling and VEGF levels in cultured REC grown in high glucose conditions. In addition, the levels of tight junction proteins, zonula occludens-1 (ZO-1) and occludin, were elevated in REC following overexpression of miR-15a and -16. Overexpression of miR-15a and -16 played a role in reducing cellular permeability through inhibition of VEGF signaling in REC cultured under high glucose conditions. Using miR-15a-transgenic mice, we demonstrated the regulatory role of miR-15a on TGF-beta3 signaling and tight junction proteins in vivo. Our outcomes suggest that miR-15a/16 maintain the retinal endothelial cell barrier by reducing TGFbeta3/VEGF signaling and increasing levels of key tight junction proteins.
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Affiliation(s)
- Eun-Ah Ye
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI, USA
| | - Li Liu
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI, USA
| | - Jena J Steinle
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI, USA; Department of Ophthalmology, Wayne State University, Detroit, MI, USA.
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Guo X, Hutcheon AEK, Zieske JD. Molecular insights on the effect of TGF-β1/-β3 in human corneal fibroblasts. Exp Eye Res 2016; 146:233-241. [PMID: 26992778 DOI: 10.1016/j.exer.2016.03.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 03/10/2016] [Accepted: 03/12/2016] [Indexed: 01/01/2023]
Abstract
Transforming growth factor β (TGF-β) plays a critical role in wound healing and the pathogenesis of fibrosis (scarring). Three isoforms of TGF-β have been identified in mammals. Previous studies have shown that the addition of TGF-β1 (T1) or -β2 (T2) to human corneal fibroblasts (HCF) cultured in a 3-dimensional construct resulted in a fibrotic matrix, while the addition of TGF-β3 (T3) resulted in the production of enhanced non-fibrotic matrix as compared to control (Vitamin C [VitC] only). In the current investigation, we undertook the molecular comparison of fibrosis-related gene expression in T1 or T3-treated HCF to gain further insights into the regulation and roles of these two isoforms on the fibrotic response. HCF were cultured in 100 mm dishes in basic medium (Eagles minimum essential medium [EMEM] with 10% fetal bovine serum [FBS]). At 70-80% confluency, cells were exposed to basic medium with 0.5 mM 2-O-α-d-glucopyranosyl-l-ascorbic acid (VitC) ± 2 ng/ml of T1 or T3. After 4 h or 3 days, cells were harvested, and mRNA or protein was isolated. Fibrosis related mRNA levels were assayed using a commercial qRT-PCR Array. Selected proteins were examined using Western blotting (WB). Experiments were performed 6 times for the qRT-PCR and 4 times for WB for each condition. qRT-PCR results showed that most of the fibrosis-related genes were up or downregulated in HCF exposed to T1 or T3 as compared with VitC control. At 4 h, only Smad7 expression was significantly altered in T3-treated HCF, compared to T1, and at 3 days, five genes were altered. WB confirmed that T1 significantly decreased Smad7 expression compared to T3 and control, and that the expression of thrombospondin-1 in T3-stimulated HCF was enhanced compared to T1-treated cells. Finally, both T1 and T3 decreased Smad3 expression dramatically at both time points. At early time points, T1 and T3 have similar effects on expression of fibrosis related genes; however, with a longer exposure, an increasing number of genes were differentially expressed. Interestingly, most of the differentially expressed gene products are secreted by the cells and may be related to the modulation of extracellular matrix.
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Affiliation(s)
- Xiaoqing Guo
- Schepens Eye Research Institute/MEE and Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
| | - Audrey E K Hutcheon
- Schepens Eye Research Institute/MEE and Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
| | - James D Zieske
- Schepens Eye Research Institute/MEE and Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
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