1. Enamel Anomalies in a Pachyonychia Congenita Patient with a Mutation in KRT16 
Olivier Duverger, Michael A. Cross, Frances J.D. Smith, Maria I. Morasso 
Journal of Investigative Dermatology 
Volume 139, Issue 1, Pages (January 2019)
DOI: /j.jid
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2. Figure 1
K16 incorporation into dental enamel and third molar extracted from a patient with PC-K16. (a) Immunohistochemical analysis of K16 expression in rat enamel organ at postnatal day 10. Nuclei are stained with DAPI (blue). Inset at the top shows an enlarged view of Tomes’ processes. The white arrowheads mark transverse bands of K16 incorporated into the core of the developing enamel rods. Scale bar: 100 μm. (b) Immunohistochemical analysis of K16 distribution on polished mesial-distal sections of mature human enamel. Scale bar: 100 μm (left panel), 20 μm (inset right panel). The white arrowheads mark transverse bands of K16 staining detected in the core of mature enamel rods. (c) Chromatograph on the left shows wild-type sequence of KRT16 exon 1 at position c.367–381. Chromatograph on the right shows equivalent region from a patient with PC with heterozygous mutation c.374A>G leading to missense mutation p.Asn125Ser (K16N125S). Schematics in the lower panel shows the position of the N125S amino-acid substitution at the beginning of the rod domain in K16. (d) Plantar keratoderma and toenail dystrophy exhibited by the patient with PC-K16. Insets show an enlarged view of plantar keratoderma and nail dystrophy. (e) Micro-computed tomography 3D reconstruction of a wisdom tooth extracted from a healthy control and a patient with PC who is heterozygous for the mutation described in (C). White arrowheads indicate small defects on the enamel surface, with the inset displaying a magnified image of a defect. (f) Three-axis sections of the molar on which enamel (En) and dentin (De) can be distinguished. Am, ameloblasts; COR, coronal; DEJ, dentin-enamel junction; IR, interred; PC, pachyonychia congenital; R, rod; SAG, sagittal; SI; stratum intermedium; TP, Tomes’ processes; TRA, transverse.
Journal of Investigative Dermatology  , DOI: ( /j.jid )
Copyright © 2018 The Authors Terms and Conditions

3. Figure 2
Enamel defects in a patient with PC-K16 and effects of p.Asn125Ser on the assembly of K16 filaments. (a) Scanning electron microscopy analysis of the polished transverse section of wisdom teeth from patients with PC-K16 and control patients. Sections were taken in the area of the cusps and in a plane perpendicular to the orientation of the enamel rods. Scale bar: 10 μm. The white arrowheads indicate a fissure going through multiple rods. (b) Scanning electron microscopy (SEM) analysis of the polished mesial-distal section of wisdom teeth from patients with PC and control patients. The white arrowheads indicate numerous fissures running across enamel rods in the inner enamel region. Scale bar: 100 μm. (c) Immunohistochemical detection of K16 (green) on the polished section of human third molar extracted from patients with PC and control patients. The white arrowheads indicate aggregates of different sizes. The two panels on the right side correspond to the area shown in the SEM image in (b) and indicate that the fissures in enamel coincide with accumulation of aggregated K16. Scale bar: 50 μm. (d) Schematic representation of pBi4-GFP/K16 bidirectional constructs used for tetracycline inducible expression of GFP with KRT16WT or KRT16A374G (produces K16N125S). When transfected into cells expressing the transactivator rTA, transgene expression through binding of rTA to the tetracycline responsive element (TRE) can be induced by the addition of doxycycline (Dox) to the culture medium. (e) Detection of GFP induction in ameloblast-like cells stably expressing rTA (ALC-TetON) transfected with pBi4-GFP/K16 constructs and grown with or without Dox. Scale bar: 150 μm. (f) Immunohistochemical analysis of K16 subcellular distribution (red) in ALC-TetON cells producing K16WT or K16N125S. Nuclei are stained with DAPI (blue), and actin filaments are stained with phalloidin conjugated to Alexa Fluor 647 (white). Scale bar: 10 μm. ALC, ameloblast-like cell; De, dentin; DEJ, dentin-enamel junction; En, enamel; PC, pachyonychia congenital.
Journal of Investigative Dermatology  , DOI: ( /j.jid )
Copyright © 2018 The Authors Terms and Conditions