Immunohistochemical Expression of Placental Form of Glutathione S-transferase (GST-pi) in Fetal Skin / 대한피부과학회지

BACKGROUND: Glutathione S-transferases(GST) are a family of multi-functional enzymes involved in cellular detoxification and excretion of a variety of exogenous and endogenous toxic or carcinogenic compounds. The GST family has been divided into three classes, alpha, mu, and pi, based on substrate specificity and sequence homology. GST-pi is an acidic type and predominant in skin, small intestine, breast, lung and prostate. The overexpression of GST-pi associated with skin tumor and tumor-like lesion suggests that GST-pi is a major detoxifying enzyme in skin tumors. OBJECTIVE: The purpose of this study was to observe the expression and the distribution pattern of GST-pi in the human fetal skin. METHODS: Skin was obtained from the scalp, chest, and sole of 49 human fetuses, ranging from 8th to 40th weeks of gestational age. Immunohistochemical staining was performed using avidin biotin peroxidase complex method on paraffin embedded tissue using antirabbit polyclonal antibody against the human GST-pi. RESULTS: GST-pi was expressed in intermediated layer of epidermis at 8th week, and gradually increased in strength of expression stronger in suprabasal layer. In hair unit, GST-pi was expressed in sebaceous gland, bulge, hair matrix cell and outer root sheath cell from 15th week. In eccrine gland, also GST-pi was expressed in central differentiated cells of intradermal eccrine duct from 18th week, and in terminal duct and acini from 26th week of fetal age. CONCLUSION: GST-pi was expressed from the 8th week of gestation suggesting that GST-pi plays an important role in detoxification for the protection of the skin in fetal stage from the various toxic agent.

CHARACTERISTICS OF INSULIN-LIKE GROWTH FACTOR-Ⅰ RECEPTOR EXPRESSION IN FETAL AND ADULT SKINS / 解放军医学杂志

Localization and expression of two subunits (IGF ⅠR? and IGF ⅠR?) of insulin like growth factor Ⅰ receptor and phosphorylated tyrosine proteins (P Tyr) in skins at different developmental stages were studied in order to explore their potential biological significance. Immunohistochemistry and pathological methods were used to detect the expression intensity and distribution of IGF ⅠR?, IGF ⅠR? and P Tyr in skins of 12 fetuses with different gestational ages and 8 adults. The results showed that positive immunohistochemical signals of IGF ⅠR?, IGF ⅠR? and P Tyr could be found in fetal and adult skins. Along with growth and development of the fetus, the positive cell rates of IGF ⅠR?, IGF ⅠR? and P Tyr in skins elevated progressively. In adult skins, IGF ⅠR was mainly located in the cell membrane of epidermal cells, while P Tyr was chiefly distributed in epidermal cells and some fibroblasts. These results suggested that IGF ⅠR and its mediating signaling pathway might be involved in cutaneous development at embryonic stage, in cutaneous structure and function maintenance, and in wound healing at postnatal stage.

CHANGE OF EXTRACELLULAR-SIGNAL REGULATED-PROTEIN KINASE1/2 SIGNALING PATHWAY IN SKIN AT DIFFERENT DEVELOPMENT STAGES / 解放军医学杂志

The purpose of this study was to investigate the localization and expression characteristics of phosphorylated form of extracellular-signal regulated-protein kinasel/2 (p-ERKl/2), Ras and C-fos in skin at different development stages and to explore their potential biological significance. Immunohistochemistry and pathological methods were used to detect the expression intensity and distribution of p-ERKl/2, Ras and C-fos in skin of 8 fetuses with different gestational ages (13 to 31 weeks) and 8 adults. Positive immunohistochemical signals of p-ERK1/2, Ras and C-fos. could be found in fetal and postnatal skins. Along with the increment in gestational age, the positive cell rates of p-ERK1/2, Ras and C-fos in the skin elevated progressively. In skins derived from the fetus of late-trimester pregnancy and adult, the positive rates of these three proteins were significantly increased in comparison with skin from the early-trimester fetus (P

Gene expression of mitogen-activated protein kinases in fetal skin at different developmental stages and its potentially biological siginificance / 解放军医学杂志

Objective To explore the change in gene expression of extracellular signal regulated protein kinase1 (erk1),erk2,p38MAPK and 3 c-Jun N- terminal kinases (jnk1,jnk2,jnk3) in fetal skin at different developmental stages and children skin. Methods After morphological characteristics of fetal skin at different developmental stages were examined histologically,gene expressions of erk1,erk2,p38MAPK,jnk1,jnk2 and jnk3 were determined with reverse transcription-polymerase chain reaction analysis (RT-PCR). Results Compared with early gestational fetal skin,the levels of gene expression of erk1 and erk2 showed no substantial change in late gestational fetal skin,while the contents of transcripts of p38MAPK and jnk1 were significantly decreased,the expressions of mRNA of jnk2 and jnk3 were obviously elevated. In children skin,gene expressions of erk2,p38MAPK and jnk1 were even more remarkably lowered. In contrary,gene expressions of jnk2 and jnk3 were marked enhanced. Conclusion The relative elevation of gene transcription of erk2 and p38MAPK and the inhibition of gene expression of jnk2 and jnk3 in fetal skin of earlier developmental stage might be related to fetal scarless healing.

Expression patterns and significance of different genes in developing stage of human fetal skin / 解放军医学杂志

Objective To comprehensively analyse the transcriptional changes of genes and their biologic significance that occurred in the process of development of human fetal skin by using high-density oligonucleotide DNA array. Methods Samples of human fetal skin were obtained from aborted fetuese of 10W, 15W, 24W, 32W EGA (estimated gestational age) respectively. Total RNAs were isolated from of skin specimens of fetuses of different EGA, and mRNAs were purified and labeled with incorporation of fluorescent dUTP to prepare the hybridization probes by using reverse transcription polymerase chain reaction (RT-PCR). Approximately 21 329 human genes were spotted on a chemical-material-coated-glass plate in array. Results According to the hybridization results from oligonucleotide DNA microarray, gene expresion patterns and functions were analysed. Gene-chip disclosed a large scale of information in developmental human fetal skin, rendering a convenient way to investigate the temporal and spatial expressions of gene profile among skin cells. Many specific genes transcription expressed differently at different stages of development of fetal skin, suggesting their key roles in development, differentiation and regulation. Conclusions Microarray or DNA chip technology has revolutioned biological research by empowering to broaden the scope of collecting genomic information. Therefore, microarray-based study is able to reveal a substantial number of genes which might participate in embryogenesis and development of human skin. The present study demonstrated a previously unrecongnized role of gene expression in the control of human fetal skin growth and structure during its developmental stage. A complicated network of skin development process was fairly well characterized.

Localization and expression of TGF-? _(1,2) in fetal and adult skins / 中国病理生理杂志

AIM: To explore the localization and expression of transfo rming grow th factor-? 1,2 (TGF-? 1,2 ) and alpha-smooth muscle actin (?- ASMA) in fetal a nd adult skins. METHODS: Skins of 15 cases of fetuses with different gestational ages and 5 cases of adults were taken, embedded with paraffin wax, and sectione d. Immunohistochemistry method and pathological method were used to detect the e xpression intensity and distribution of TGF-? 1,2 and ?-ASMA. RESULTS: Positive immunohistochemical signals of TGF-? 1,2 and ?-A SMA were found in fetal and adult skins. In skins derived from young fet us, the positive signals of these three proteins were very weak. Along with the incr ement in gestational age, the positive cellular rates of TGF-? 1,2 and ?- ASMA were elevated pro gressively. In elder fetal and adult skins, TGF-? 1,2 were mostly distributed i n epidermal cells, endothelial cells and some fibroblasts, while ?-ASMA was mainly located in myofibroblasts and sweat gland epithelial cells. CONCLUSION: The endo genous TGF-? 1,2 might be involved in the cutaneous development at embryoni c stage, in the cutaneous structure maintenance at adult stage, and in the wound healing af ter injury.

The Changes of Cytokeratin 19 and bcl-2 Expression during Hair Follicle Morphogenesis in Human Fetal Skin / 대한피부과학회지

BACKGROUND: During human skin development, hair follicles dynamically develop to adult hair structures through the hair germ, hair peg and bulbous hair peg. In this perspective, it is thought that the distributions of stem cells changes following the stage of the hair follicle morphogenesis. OBJECTIVE: The purpose of this study was to observe the distribution of stem cells following the stage of hair follicle morphogenesis. METHODS: Skin was obtained from the abdomen skin of 15 human fetuses, ranging from 10 to 23 weeks of gestational age. Immunoperoxidase staining was performed on frozen sections using monoclonal antibodies to cytokeratin 19, known as a stem cell marker, and bcl-2, a factor to prevent cells from entering the apoptotic pathway. RESULTS: 1. Cytokeratin 19 was expressed in the periderm, basal cell layer and condenced cells constituting the hair germ and peg. In the early bulbous hair peg stage, it was expressed in the entire outer root sheath cells, the bulge area and basal cells of the hair bulb. In the late bulbous hair peg stage, it was expressed in the bulge area, outer root sheath cells only of inferior portion and some of the germinative cells of the hair bulb. 2. Bcl-2 was expressed in the basal cells intermittently, condenced cells constituting the hair germ and aggregates of dermal mesenchymal cells concentrating along the hair germ. In the hair peg stage, it was expressed in the entire basal cell layer, condenced cells constituting the hair peg and aggregates of dermal mesenchymal cells along the hair peg. In t.he bulbous hair peg stage it was expressed in the basal cells of the infundibulum, sebaceous gland, bulge area, germinative cells of the hair bulb and the dermal papilla cells. CONCLUSION: From the results obtained, we thought that the distribution of stem cells is dynamically changing following the stages of the hair follicle morphogenesis. It was also speculated that bcl-2 might have an important role in dermoepidermal interactions during hair follicle morphogenesis.

Isolation and pure culture of microvascular endothelial cells from the fetal skin

Microvascular endothelial cells were purely isolated from human fetal skin using magnetic particles. The principle of this technique is based on the selective binding of the lectin Ulex europaeus I (UEA I) to the endothelial cell surface via fucose residues. Initially UEA I was covalently bound to tosyl-activated magnetic polydisperse polymer particles (Dynabeads) and then the UEA I-coated beads were collected using a magnetic particle concentrator (MPC). Endothelial cells were isolated by extracting microvascular segments from trypsin-treated fetal skin tissue and were purified by sieving with nylon mesh and by 35% Percoll gradient centrifugation. For further purification, the obtained cells were incubated with UEA I-coated Dynabeads. The endothelial cells bound to the Dynabeads were collected using MPC. This is a simple and reproducible technique for isolating a pure population of microvascular endothelium from the fetal skin.

Morphological Observations on the Epidermal Development of Human Fetal Skin

To observe developing process of human fetal skin during intrauterine life, morphological studies in light microscopic level were made based on 27 human embryos and 76 fetuses ranging from 4 to 40 gestation weeks. The fetuses were the products of induced abortion and were found to have no associated diseases of congenital anomalies at the autopsy. Ten different portions of the body were sampled and examined. They were scalp, forehead, face, chest, abdomen, back, palm, sole, finger and toe. In embryos two different portions; cephalic and caudal portions were examined: The following results were obtained: 1) A single layer of undifferentiated cell was the primitive epidermis at the 4th week and it was followed by two layered epidermis consisting of periderm and primitive basal cell layer. Epidermal ridges started to develop along with primitive eccrine and hair germs as clustering of basal cells at the llth week. Stratum inter-medium was formed at the 12th week, and primitive granular cell layers and keratin formation in association with hair follicles at the 19th week forming earliest adult type epidermis, followed by progressive maturation. 2) The thickness of the fetal epidermis and keratin layer increased as the fetal age approached to the term with its slightly different developmental pattern by the site of body. Cephalic protions developed slightly earlier than the other parts. 3) The developmental pattern of various portions of epidermis could be categorized into three groups; (1) scalp, forehead and face; (2) chest, abdomen and back; (3) palm, sole, finger and toe.

Immunohistochemical Staining of S - 100 Protein in Human Fetal Skin / 대한피부과학회지

The authors attempted to examine the distribution of S-100 protein in the human fetal skin. Immunohistochemical staining(ABC rnethod) using anti-S-100 antibodies was carried out on skin specimens taken from 11 human fetuses ranging from 9 weeks to 27 weeks of estimated gestational age. At 9 weeks of estimated gestational age, the embryonic epidermis consisted of three cell layers,' the basal layer, intermediate layer and periderm, all of them being stained for S-100 protein. But after 18 weeks, the basal layer changed to be negative. Granular and cornified layer's, beginning their development at 22 weeks, were not stained for S-100 protein. Hair germ of 12 week-fetuses was recognized unstained as a bulge of basal cells. In fully differentiated structural components of the hair follicle after 18 weeks, the outer root sheath only was stained for S-100 protein whereas the inner root sheath, hair matrix cells and sebaceous glands were unstained. Eccrine gland germs developed at 12 weeks of embryonic life as undulation of the basal layer and were not, stained. And at 22 weeks, the secretory portion of the eccrine glands were formed in the dermis and stained for S-100 protein. Our present study suggests that the expression of S-100 protein can undergo considerable changes during ernbryonic differentiation in the epidermis and epidermal appendages.

Characteristics of bax, bcl-2 and p53 gene expression in children and fetal skin at different developmental stages / 中国病理生理杂志

AIM: To investigate gene expression of bax, bcl-2 and p53 in fetal skin at different gestational ages and children skin in order to explore their potentially biological significance. METHODS: Apoptosis in skin specimens was determined by terminal deoxynucleotidy transferase mediated dUTP-biotin nick-end labeling technique (TUNEL). Gene expressions of bax, bcl-2 and p53 in skin at different developmental stages was examined with reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Along with fetal growth and development, the incidence rate of apoptosis was increased progressively in skin. In skin from early gestational fetus, bcl-2 was strongly expressed. This gene expression was progressively decreased with increment in gestational age. In children skin, the mRNA content of this gene was significantly reduced compared with fetal skin (P

Gene expression of epidermal growth factor, c-fos and c-myc in fetal and children skins / 解放军医学杂志

Objective To investigate gene expression of epidermal growth factor (EGF), its receptor (EGFR) and two protooncogenes (c-fos and c-myc), in fetal skin at different development stages and children skin and to delineate their potential biological significance. Methods Fetal skin biopsies of human embryo were obtained from spontaneous abortions at different gestational ages from 13 to 32 weeks and children skin specimens were collected from patients undergoing plastic surgery. After morphological characteristics of skin at different development stages were detected with histological methods, gene expressions of EGF, EGFR, c-fos and c-myc in skin at different development stages were examined with reverse transcription-polymerase chain reaction analysis (RT-PCR). Results Gene expression of EGF, EGFR, c-fos or c-myc could all be detected in fetal and childern skins. In fetal skin, the gene expression of these 4 genes was weak. Gene expression of these genes in skin was progressively enhanced with increasing gestational age. In children skin, the mRNA contents of these 4 genes were significantly increased in comparison with those in fetal skin (P