{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T14:07:09Z","timestamp":1777385229187,"version":"3.51.4"},"reference-count":35,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2024,4,4]],"date-time":"2024-04-04T00:00:00Z","timestamp":1712188800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"NIH","award":["R01 EY29071"],"award-info":[{"award-number":["R01 EY29071"]}]},{"name":"NIH","award":["R01 EY31051"],"award-info":[{"award-number":["R01 EY31051"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cells"],"abstract":"<jats:p>(1) Background: Our previous data indicated that disturbance of the Transforming Growth Factor beta (TGFB) signaling pathway via its Type-2 Receptor (TGFBR2) can cause a Corneal Ectasia (CE)-like phenotype. The purpose of this study is to elucidate whether the SMAD4-dependent signaling pathway is involved in the TGFBR2-related CE-like pathogenesis. (2) Methods: Smad4 was designed to be conditionally knocked out from keratocytes. Novel triple transgenic mice, KerartTA; Tet-O-Cre; Smad4flox\/flox (Smad4kera-cko), were administered with doxycycline (Dox). Optical Coherence Tomography (OCT) was performed to examine Central Corneal Thickness (CCT), Corneal Radius, Anterior Chamber and CE-like phenotype and compared to the littermate Control group (Smad4Ctrl). (3) Results: The OCT revealed normal cornea in the Smad4Ctrl and a CE-like phenotype in the Smad4kera-cko cornea, in which the overall CCT in Smad4kera-cko was thinner than that of Smad4Ctrl at P42 (n = 6, p &lt; 0.0001) and showed no significant difference when compared to that in Tgfbr2kera-cko. Furthermore, the measurements of the Anterior Chamber and Corneal Radius indicated a substantial ectatic cornea in the Smad4kera-cko compared to Smad4Ctrl. The H&amp;E staining of Smad4kera-cko mimics the finding in the Tgfbr2kera-cko. The positive immunostaining of cornea-specific marker K12 indicating the cell fate of cornea epithelium remained unchanged in Smad4kera-cko and the Proliferating Cell Nuclear Antigen (PCNA) immunostaining further indicated an enhanced proliferation in the Smad4kera-cko. Both immunostainings recapitulated the finding in Tgfbr2kera-cko. The Masson\u2019s Trichrome staining revealed decreased collagen formation in the corneal stroma from both Smad4kera-cko and Tgfbr2kera-cko. The collagen type 1 (Col1a1) immunostaining further confirmed the reduction in collagen type 1 formation in Smad4kera-cko. (4) Conclusions: The aforementioned phenotypes in the Smad4kera-cko strain indicated that the SMAD4-dependent signaling pathway is involved in the pathogenesis of the CE-like phenotype observed in Tgfbr2kera-cko.<\/jats:p>","DOI":"10.3390\/cells13070626","type":"journal-article","created":{"date-parts":[[2024,4,4]],"date-time":"2024-04-04T06:57:34Z","timestamp":1712213854000},"page":"626","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["SMAD4-Dependent Signaling Pathway Involves in the Pathogenesis of TGFBR2-Related CE-like Phenotype"],"prefix":"10.3390","volume":"13","author":[{"given":"Yen-Chiao","family":"Wang","sequence":"first","affiliation":[{"name":"Edith Crawley Vision Research Center, Department of Ophthalmology, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA"},{"name":"Department of Anesthesia, School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA"},{"name":"School of Optometry, Indiana University, Bloomington, IN 47405, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Olivia Betty","family":"Zolnik","sequence":"additional","affiliation":[{"name":"School of Optometry, Indiana University, Bloomington, IN 47405, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chia-Yang","family":"Liu","sequence":"additional","affiliation":[{"name":"Edith Crawley Vision Research Center, Department of Ophthalmology, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA"},{"name":"School of Optometry, Indiana University, Bloomington, IN 47405, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,4]]},"reference":[{"key":"ref_1","unstructured":"Gandhi, S., and Jain, S. (2014). Keratoprostheses and Artificial Corneas: Fundamentals and Surgical Applications, Springer."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"108137","DOI":"10.1016\/j.exer.2020.108137","article-title":"Composition, structure and function of the corneal stroma","volume":"198","author":"Espana","year":"2020","journal-title":"Exp. Eye Res."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Gould, D., and McLellan, G.J. BSAVA manual of canine and feline ophthalmology. BSAVA manual of canine and feline ophthalmology., 2014.","DOI":"10.22233\/20412495.0115.14"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/bs.pmbts.2015.04.001","article-title":"Overview of the cornea: Structure, function, and development","volume":"134","author":"Eghrari","year":"2015","journal-title":"Prog. Mol. Biol. Transl. Sci."},{"key":"ref_5","first-page":"e428","article-title":"The role of corneal stroma: A potential nutritional source for the cornea","volume":"3","author":"Zhang","year":"2017","journal-title":"J. Nat. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/j.gene.2018.10.074","article-title":"Smad4-dependent regulation of type I collagen expression in the muscle of grass carp fed with faba bean","volume":"685","author":"Yu","year":"2018","journal-title":"Gene"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2000","DOI":"10.1046\/j.1523-1755.2003.00009.x","article-title":"Role of Smad4 on TGF-\u03b2\u2013induced extracellular matrix stimulation in mesangial cells","volume":"63","author":"Tsuchida","year":"2003","journal-title":"Kidney Int."},{"key":"ref_8","first-page":"565","article-title":"Role of transforming growth factor Beta in corneal function, biology and pathology","volume":"10","author":"Tandon","year":"2010","journal-title":"Curr. Mol. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.clae.2010.04.006","article-title":"Keratoconus: A review","volume":"33","author":"Wolffsohn","year":"2010","journal-title":"Contact Lens Anterior Eye"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1016\/j.jtos.2023.06.014","article-title":"Transforming growth factor beta receptor 2 (Tgfbr2) deficiency in keratocytes results in corneal ectasia","volume":"29","author":"Wang","year":"2023","journal-title":"Ocul. Surf."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1864","DOI":"10.1038\/s41467-018-03646-6","article-title":"Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases","volume":"9","author":"Iglesias","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_12","first-page":"577","article-title":"Keratoconus in vitro and the key players of the TGF-\u03b2 pathway","volume":"21","author":"Priyadarsini","year":"2015","journal-title":"Mol. Vis."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"582","DOI":"10.1038\/ejhg.2017.4","article-title":"Collagen synthesis disruption and downregulation of core elements of TGF-\u03b2, Hippo, and Wnt pathways in keratoconus corneas","volume":"25","author":"Kabza","year":"2017","journal-title":"Eur. J. Hum. Genet."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"616","DOI":"10.1038\/nrm3434","article-title":"TGF\u03b2 signalling in context","volume":"13","year":"2012","journal-title":"Nat. Rev. Mol. Cell Biol."},{"key":"ref_15","unstructured":"Wheeler, J., Hauser, M.A., Afshari, N.A., Allingham, R.R., and Liu, Y. (2012). The genetics of keratoconus: A review. Microscopy, 001."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1016\/j.tcb.2008.06.006","article-title":"Decoding the quantitative nature of TGF-\u03b2\/Smad signaling","volume":"18","author":"Clarke","year":"2008","journal-title":"Trends Cell Biol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1186\/1471-213X-9-54","article-title":"Smad4-dependent pathways control basement membrane deposition and endodermal cell migration at early stages of mouse development","volume":"9","author":"Costello","year":"2009","journal-title":"BMC Dev. Biol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2019","DOI":"10.1177\/15353702211012288","article-title":"Correlation between TGF-\u03b22\/3 promoter DNA methylation and Smad signaling during palatal fusion induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin","volume":"246","author":"Chen","year":"2021","journal-title":"Exp. Biol. Med."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4800","DOI":"10.1167\/iovs.17-22661","article-title":"Generation and characterization of a novel mouse line, keratocan-rtTA (KeraRT), for corneal stroma and tendon research","volume":"58","author":"Zhang","year":"2017","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_20","unstructured":"Ambr\u00f3sio, R., and Wilson, S.E. (2003). Seminars in Ophthalmology, Taylor & Francis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/S0039-6257(01)00254-5","article-title":"LASIK Complications: Etiology, Management, and Prevention","volume":"46","author":"Azar","year":"2001","journal-title":"Surv. Ophthalmol."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Cortina, M.S., and de la Cruz, J. (2015). Keratoprostheses and artificial corneas. Fundam. Surg. Appl., 2015.","DOI":"10.1007\/978-3-642-55179-6"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"22","DOI":"10.3928\/1081597X-20131217-02","article-title":"Intrastromal Corneal Ring Segments Implantation in Patients with Keratoconus: 10-Year Follow-Up","volume":"30","author":"Torquetti","year":"2014","journal-title":"J. Refract. Surg."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.optom.2013.12.001","article-title":"Corneal collagen cross-linking: A review","volume":"7","year":"2014","journal-title":"J. Optom."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1016\/j.ijbiomac.2020.06.075","article-title":"Current methods of collagen cross-linking: Review","volume":"161","author":"Adamiak","year":"2020","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"991","DOI":"10.1016\/j.jcrs.2014.04.013","article-title":"Biomechanics of corneal ectasia and biomechanical treatments","volume":"40","author":"Roberts","year":"2014","journal-title":"J. Cataract Refract. Surg."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"842","DOI":"10.1016\/j.jcrs.2015.03.010","article-title":"Reshaping procedures for the surgical management of corneal ectasia","volume":"41","author":"Ziaei","year":"2015","journal-title":"J. Cataract. Refract. Surg."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1097\/ICU.0b013e3281a7ecaa","article-title":"Current treatment options for corneal ectasia","volume":"18","author":"Tan","year":"2007","journal-title":"Curr. Opin. Ophthalmol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1038\/35085597","article-title":"TAK1 is a ubiquitin-dependent kinase of MKK and IKK","volume":"412","author":"Wang","year":"2001","journal-title":"Nature"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"522","DOI":"10.1016\/j.tips.2012.06.007","article-title":"Targeting of TAK1 in inflammatory disorders and cancer","volume":"33","author":"Sakurai","year":"2012","journal-title":"Trends Pharmacol. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1087","DOI":"10.1038\/ni1255","article-title":"Essential function for the kinase TAK1 in innate and adaptive immune responses","volume":"6","author":"Sato","year":"2005","journal-title":"Nat. Immunol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1667","DOI":"10.1038\/cdd.2014.123","article-title":"TAK1 control of cell death","volume":"21","author":"Mihaly","year":"2014","journal-title":"Cell Death Differ."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1038\/eye.2014.333","article-title":"Acute corneal hydrops in keratoconus: A national prospective study of incidence and management","volume":"29","author":"Barsam","year":"2015","journal-title":"Eye"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1097\/ICU.0b013e328354a2a8","article-title":"Management of acute corneal hydrops in ectatic corneal disorders","volume":"23","author":"Sharma","year":"2012","journal-title":"Curr. Opin. Ophthalmol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1738","DOI":"10.1016\/S0161-6420(94)31110-9","article-title":"Acute Corneal Hydrops in Keratoconus","volume":"101","author":"Tuft","year":"1994","journal-title":"Ophthalmology"}],"container-title":["Cells"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4409\/13\/7\/626\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:23:17Z","timestamp":1760106197000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4409\/13\/7\/626"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4,4]]},"references-count":35,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2024,4]]}},"alternative-id":["cells13070626"],"URL":"https:\/\/doi.org\/10.3390\/cells13070626","relation":{},"ISSN":["2073-4409"],"issn-type":[{"value":"2073-4409","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4,4]]}}}