The development of the basement membrane and collagen fibrils below placodes, including the corneal region of the ectoderm, lens epithelium, nasal plate, and auditory vesicle in anuran larvae was observed by transmission electron microscopy and compared with that in nonplacodal regions such as the epidermis, neural tube, and optic vesicle. In the corneal region the lamina densa becomes thick concomitantly with the development of the connecting apparatuses such as hemidesmosomes and anchoring fibrils. The collagen fibrils increase in number and form a multilayered structure, showing similar morphology to the connective tissues below the epidermis. These two areas, i.e., the corneal region and epidermis, possess much collagenous connective tissue below them. On the other hand, the neural tube and ophthalmic vesicle that originated from the neural tube each have a thin lamina densa and a small number of underlying collagen fibrils. The lamina densa does not thicken and the number of collagen fibrils do not significantly increase during development. These two areas possess little extracellular matrix. The nasal plate and auditory vesicle show intermediate characteristics between the epidermis-type and the neural tube-type areas. In these areas, the lamina densa becomes thick and hemidesmosomes and anchoring fibrils develop. The number of collagen fibrils increases during development, but does not show an orderly arrangement; rather, they are randomly distributed. It is thought that the difference in the arrangement of collagen fibrils in different tissues is due to differences in the extracellular matrix around the collagen fibrils. Placodal epithelia have the same origin as epidermis, but during development their morphological characteristics differ and they are not associated with the pattern of extracellular matrix with characteristics of epidermal and corneal multilayered collagen fibril areas.
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http://dx.doi.org/10.1002/jmor.10061 | DOI Listing |
J Mater Chem B
January 2025
Key Laboratory of Leather Chemistry and Engineering (Ministry of Education), Sichuan University, Chengdu 610065, P. R. China.
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View Article and Find Full Text PDFSci Rep
December 2024
Department of Chemistry and Biochemistry, Northern Arizona University, Flagstaff, AZ, USA.
Idiopathic pulmonary fibrosis (IPF) is a fatal disease defined by a progressive decline in lung function due to scarring and accumulation of extracellular matrix (ECM) proteins. The SOCS (Suppressor Of Cytokine Signaling) domain is a 40 amino acid conserved domain known to form a functional ubiquitin ligase complex targeting the Von Hippel Lindau (VHL) protein for proteasomal degradation. Here we show that the SOCS conserved domain operates as a molecular tool, to disrupt collagen and fibronectin fibrils in the ECM associated with fibrotic lung myofibroblasts.
View Article and Find Full Text PDFPurpose: Using a thin semitendinosus tendon as an autograft is a risk factor for poor clinical outcomes after anterior cruciate ligament reconstruction. Preoperative evaluation of the cross-sectional area of the semitendinosus tendon using magnetic resonance imaging is useful. However, studies comparing the cross-sectional area of the semitendinosus tendon on magnetic resonance imaging and the collagen fibril diameter of the semitendinosus tendon are lacking.
View Article and Find Full Text PDFBiomimetics (Basel)
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Center for Advanced Eye Care, Vero Beach, FL 32960, USA.
We have compared the biomechanical properties of human and porcine corneas using vibrational optical coherence tomography (VOCT). The elastic modulus of the cornea has been previously reported in the literature to vary from about several kPa to more than several GPa based on the results of different techniques. In addition, the formation of corneal cones near the central cornea in keratoconus has been observed in the clinic.
View Article and Find Full Text PDFBiomech Model Mechanobiol
December 2024
Department of Biomedical Engineering, Virginia Commonwealth University, 401 W. Main St., Richmond, VA, 23284, USA.
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