ABSTRACT
Abstract The aim of this study was to determine expression, not previously described, of PLUNC (palate, lung, and nasal epithelium clone) (BPI-fold containing) proteins in major and minor salivary glands from very early fetal tissue to the end of the second trimester and thus gain further insight into the function of these proteins. Early fetal heads, and major and minor salivary glands were collected retrospectively and glands were classified according to morphodifferentiation stage. Expression of BPI-fold containing proteins was localized through immunohistochemistry. BPIFA2, the major BPI-fold containing protein in adult salivary glands, was detected only in the laryngeal pharynx; the lack of staining in salivary glands suggested salivary expression is either very late in development or is only in adult tissues. Early expression of BPIFA1 was seen in the trachea and nasal cavity with salivary gland expression only seen in late morphodifferentiation stages. BPIFB1 was seen in early neural tissue and at later stages in submandibular and sublingual glands. BPIFA1 is significantly expressed in early fetal oral tissue but BPIFB1 has extremely limited expression and the major salivary BPIF protein (BPIFA2) is not produced in fetal development. Further studies, with more sensitive techniques, will confirm the expression pattern and enable a better understanding of embryonic BPIF protein function.
Subject(s)
Humans , Phosphoproteins/analysis , Salivary Glands/chemistry , Salivary Proteins and Peptides/analysis , Autoantigens/analysis , Glycoproteins/analysis , Proteins/analysis , Fetus/chemistry , Palate/embryology , Palate/chemistry , Salivary Glands/embryology , Time Factors , Tongue/embryology , Tongue/chemistry , Immunohistochemistry , Retrospective Studies , Gestational Age , Fetal Development , Epithelium/chemistry , Head/embryology , Neck/embryologySubject(s)
Humans , Infant, Newborn , Adult , Middle Aged , Glycoconjugates/metabolism , Lectins/metabolism , Palate/growth & development , Salivary Glands/growth & development , Carbohydrate Metabolism , Carbohydrates/chemistry , Glycoconjugates/analysis , Histocytochemistry , Human Development , Lectins/analysis , Palate/embryology , Salivary Glands/embryologyABSTRACT
La histogénesis de las glándulas palatinas fue estudiada desde el punto de vista estructural y citoquímico en embriones y fetos humanos de 8 a 32 semanas de desarrollo. Los primordios glandulares aparecían a las 12 semanas de vida intrauterina. Los extremos distales redondeados de los cordones epiteliales y el mesénquima circundante mostraban abundantes gránulos PAS positivos y alcianofílicos. A las 14 semanas las piezas secretorias terminales y el sistema ductal presentaban diferentes estadios de diferenciación estructural. Predominaban los acinos mucosos con escasos acinos mixtos, en tanto que los acinos serosos aparecían ocasionalmente. Entre las 20 y 24 semanas los acinos mucosos coloreados con azul de toluidina presentaban diferentes grados de metacromasia aún dentro de células de un mismo acino. En los conductos se identificaban células metacromáticas intercaladas con células basófilas en la cubierta epitelial. Estos hallazgos sugieren que las glándulas palatinas presentan un material histofisiológico típico entre las 14 y 20 semanas. La presencia de sustancias secretorias PAS positivas, alcianofílicas y metacromáticas en la luz acinar y contenido luminal de los conductos nos sugiere que la secreción de mucinas se inicia en la vida intrauterina