Characterization of mesenchymal cells beneath cornification of the fetal epithelium and epidermis at the face: an immunohistochemical study using human fetal specimens

Abstract

Fetal development of the face involves a specific type of cornification in which keratinocytes provide a mass or plug to fill a cavity. The epithelial-mesenchymal interaction was likely to be different from that in the usual skin. We examined expression of intermediate filaments and other mesenchymal markers beneath cornification in the fetal face. Using sections from 5 mid-term human fetuses at 14–16 weeks, immunohistochemistry was conducted for cytokeratins (CK), vimentin, nestin, glial fibrilary acidic protein, desmin, CD34, CD68 and proliferating cell nuclear antigen (PCNA). Fetal zygomatic skin was composed of a thin stratum corneum and a stratum basale (CK5/6+, CK14+, and CK19+) and, as the intermediate layer, 2–3 layered large keratinocytes with nucleus. The basal layer was lined by mono-layered mesenchymal cells (CD34+ and nestin+). Some of basal cells were PCNA-positive. In the keratinocyte plug at the external ear and nose, most cell nuclei expressed PCNA, CK5/6, CK14, and CK19. Vimentin-positive mesenchymal cells migrated into the plug. The PCNA-positive nucleus as well as mesenchymal cell migration was not seen in the lip margin in spite of the thick keratinocyte layer. The lingual epithelium were characterized by the CK7-positive stratum corneum as well as the thick mesenchymal papilla. CD68-positive macrophages were absent in the epidermis/epithelium. Being different from usual cornification of the skin, loss of a mesenchymal monolayer as well as superficial migration of mesenchymal cells might connect with a specific differentiation of keratinocyte to provide a plug at the fetal nose and ear.

Development of the squamate naso-palatal complex: detailed 3D analysis of the vomeronasal organ and nasal cavity in the brown anole Anolis sagrei (Squamata: Iguania)

“…The presence of the embryonic nasal plug is a common transient embryonic feature of amniotes. It has been found in snakes [ 66 , 69 , 72 ], lizards [ 19 , 73 ], turtle [ 69 ], Sphenodon [ 74 ] , birds [ 71 , 72 ] and mammals [ 72 , 75 ] including human [ 76 , 77 ]. The nature of the nasal plug is poorly understood.…”

Expression of Nestin, Transcription Factor SOX3 and Homeobox Protein DLX-4 in the Facial Tissue of Children with Cleft Lip and Palate

“…Nestin has also been found in preneoplastic lesions of oral epithelium and possibly is associated with differentiation, invasion and poorer prognosis in oral squamous cell carcinoma (Ravindran & Devaraj, 2015). In the facial tissue of 14 to 16 weeks old human fetuses using immunohistochemistry nestin-reactivity was seen in striated muscles, mesenchymal cells and fibers and the basal layer of the skin (Kim et al, 2016). In our study tissue samples showed prominent immunoreactivity for nestin with overall total number of nestin-positive structures higher in CBCLP tissue samples.…”

Development of the squamate naso-palatal complex: detailed 3D analysis of the vomeronasal organ and nasal cavity in the brown anole Anolis sagrei (Squamata: Iguania)

“…The presence of the embryonic nasal plug is a common transient embryonic feature of amniotes. It has been found in snakes [66,69,72], lizards [18,73], turtle [69], Sphenodon [74], birds [71,72] and mammals [72,75] including human [76,77]. The nature of the nasal plug is poorly understood.…”

“…The nature of the nasal plug is poorly understood. It is described as mass of epithelial cells [75], mass of isodiametric cells [21], peridermal plug [72,78], or structure formed by keratinocytes [77]. It has been proposed that it forms between the nasal prominences from the epithelial seam, which does not undergo disintegration [71,72], or as a proliferation of the "invaginated" oral epithelium [78], which in fact may be considered as walls of the presumptive vestibulum.…”