Comparative Analysis of the Expression of Involucrin, Filaggrin and Cytokeratin 4, 10, 16 in Cholesteatoma

BACKGROUND AND OBJECTIVES: The aim of this study is to determine whether the hyperproliferative and hyperkeratotic characters of cholesteatoma are associated with differentiation of keratinocytes in cholesteatoma by examining the localization of marker proteins, such as involucrin, filaggrin, and cytokeratins. MATERIALS AND METHODS: Immunohistochemical study was carried out in 30 cholesteatoma tissues and 10 retroauricular skins to examine the expression of involucrin, filaggrin, cytokeratin 4, 10 and 16. The staining results were graded as negative, weakly positive (70%). RESULTS: Involucrin was strongly expressed in upper spinous, granular, and corneal layer of cholesteatoma. Filaggrin was strongly expressed in granular and corneal layer of cholesteatoma. Cytokeratin 4 was expressed in basal layer of retroauricular skin, but occasionally expressed in suprabasal layer of cholesteatoma. Cytokeratin 10 was homogenously expressed in all suprabasal layer of retroauricular skin, whereas pattern of shift to surface layer was showed in cholesteatoma. Cytokeratin 16 was moderately expressed at suprabasal layer in cholesteatoma. CONCLUSIONS: It can be suggested that early differentiation of suprabasal layer may lead to hyperdifferentiation and hyperkeratosis. Different expression of cytokeratins possibly indicates the altered differentiation of cholesteatoma.

Comparative Analysis of the Expression of Involucrin, Filaggrin and Cytokeratin 4, 10, 16 in Cholesteatoma

BACKGROUND AND OBJECTIVES: The aim of this study is to determine whether the hyperproliferative and hyperkeratotic characters of cholesteatoma are associated with differentiation of keratinocytes in cholesteatoma by examining the localization of marker proteins, such as involucrin, filaggrin, and cytokeratins. MATERIALS AND METHODS: Immunohistochemical study was carried out in 30 cholesteatoma tissues and 10 retroauricular skins to examine the expression of involucrin, filaggrin, cytokeratin 4, 10 and 16. The staining results were graded as negative, weakly positive (70%). RESULTS: Involucrin was strongly expressed in upper spinous, granular, and corneal layer of cholesteatoma. Filaggrin was strongly expressed in granular and corneal layer of cholesteatoma. Cytokeratin 4 was expressed in basal layer of retroauricular skin, but occasionally expressed in suprabasal layer of cholesteatoma. Cytokeratin 10 was homogenously expressed in all suprabasal layer of retroauricular skin, whereas pattern of shift to surface layer was showed in cholesteatoma. Cytokeratin 16 was moderately expressed at suprabasal layer in cholesteatoma. CONCLUSIONS: It can be suggested that early differentiation of suprabasal layer may lead to hyperdifferentiation and hyperkeratosis. Different expression of cytokeratins possibly indicates the altered differentiation of cholesteatoma.

The Expression of Human Beta Defensins by Thermal Injury

PURPOSE: Defensins are important components of innate immune system. These peptides have antimicrobial activity against a wise variety of pathogens that associated with burn wound infection. In particular, human beta-defensins are expressed in normal epidermal region and showed differential expression of some skin disease. We investigated that expression of human beta-defensin by in vitro and ex-vivo by thermal condition. METHODS: To investigate the expression of human beta-defensins in acute burn condition, we cultured keratinocytes and used to rat's skin at this experiment. After thermal condition, we showed the expression of beta-defensins-2 (hBD-2), -3 (hBD-3), keratins, keratinocyte differentiation and junction protein levels by RT-PCR and immunohistochemistry (IHC). RESULTS: HBD-2 & involucrin were down-regulated from 1 hr to 8 hrs in mRNA level. But others were not changed in mRNA level. In protein level, hBD-3 was decreased but pan-cytokeratin and beta-catenin were not changed. CONCLUSION: HBD-2 was down-regulated in thermal injury. Because thermal injury could induce the influence of keratinocyte differentiation and the decrease of skin protection ability. Our results suggested that human beta-defensins plays an important role in protection by several injury.

Histologic morphology and involucrin, filaggrin, and keratin expression in normal canine skin from dogs of different breeds and coat types

The purpose of this study was to measure the thickness of canine epidermis at various anatomical sites according to localization of cornified envelopes (involucrin and filaggrin), keratins (keratin 10, 5), and their mRNA expression. This was done in the skin of five breeds of dogs including seven poodles, six golden retrievers, six Shih Tzus, four pugs, and four Labrador retrievers. Epidermal thickness of the stratum corneum and nucleated epidermal layer was significantly different. The greatest thickness was observed in the digital web area and the thinnest epidermis was in the axilla. Epidermal thickness was also significantly different between the breeds (p < 0.05). Immunohistochemical staining scores revealed significant decreases of involucrin, filaggrin, and keratin 10 in the ventral and weight-bearing sites, and a relative increase of keratin 5 (p < 0.05). q-PCR analysis showed that their the levels of mRNA were positively correlated with expression of the corresponding proteins in skin samples (p < 0.05). The present study is the first to report the relationship between epidermal gene expression and histologic morphology of the skin in normal dogs. Further studies will be essential to fully understand the pathogenesis of skin barrier dysfunctions in canines.

The Expressions of Cytokeratin 16, Involucrin and PCNA in Clear Cell Acanthoma on Areola / 대한피부과학회지

BACKGROUND: Clear cell acanthoma usually appears as an asymptomatic nodule on the leg. It has an unusual clinical feature in that it is presented as chronic eczema on the areola. The origin of clear cell acanthoma is not yet clear, although many hypotheses have been proposed, including a benign neoplasm or an inflammatory dermatosis. OBJECTIVE: In this study, clear cell acanthoma on the areola showing clinically eczematous features were analysed by immunohistochemical techniques, using antibodies against cytokeratin 16, involucrin and PCNA and compared with psoriasis and squamous cell carcinoma. METHODS: Using the immunohistochemical method with formalin-fixed, paraffin-embedded sections, we analysed the expression of cytokeratin 16, involucrin and PCNA in biopsy specimens of 6 cases of clear cell acanthoma on the areola, 5 cases of psoriasis, and 5 cases of squamous cell carcinoma. RESULTS: The expression of cytokeratin 16 was detected in spinous and granular layers in all cases of clear cell acanthoma and psoriasis and three cases of squamous cell carcinoma. Psoriasis showed slightly higher immunoreactivity than clear cell acanthoma and squamous cell carcinoma, but this difference was not statistically significant (p=0.142). The expression of involucrin was detected in spinous and granular layers in all cases of clear cell acanthoma, psoriasis, and squamous cell carcinoma. The immunoreactivities were similar. The expression of PCNA was detected in basal and spinous layers in two cases of clear cell acanthoma, four cases of psoriasis, and five cases of squamous cell carcinoma. The expression of PCNA was higher in psoriasis and squamous cell carcinoma than in clear cell acanthoma, and this difference was statistically significant (p=0.034, p=0.004). CONCLUSION: Clear cell acanthoma on the areola may result from increased psoriasis-like inflammatory proliferation and accelerated differentiation of keratinocytes.

The Effects of Testosterone on Skin Barrier / 대한피부과학회지

BACKGROUND: Although there are no known gender-related differences in permeability barrier function in adults, estrogen accelerates whereas testosterone retards barrier development in fetal skin. However, there have been few studies concerning the effects of testosterone on the skin barrier. OBJECT: We evaluated the effects and mechanisms of testosterone on the skin barrier. METHODS: In this experiment, hairless mice were divided into three groups; sham-operated, castrated and testosterone-replacement castrated group. Testosterone was administered subcutaneously once a day for 7 days. We performed a skin biopsy at 7 days and performed hematoxyline-eosin staining, calcium-ion capture cytometry and the immunohistochemical examination of involucrin, loricrin, filaggrin and proliferating cell nuclear antigen (PCNA). The specimens were prepared for electron microscopy using RuO4 and OsO4 postfixation. RESULTS: The results were summarized as follows 1. Light microscopic findings of the testosterone-replacement castrated group showed apparent hyperkeratosis and acanthosis, not present in the sham-operated and castrated group. 2. Whereas the expression of involucrin, loricrin and filaggrin of immunohistochemical staining and in situ hybridization of the sham-operated and castrated group were normal, it was abnormal in the testosterone-replacement castrated group. 3. Labelling indices for PCNA in the sham-operated and castrated group were not statistically different, but the testosterone-replacement castrated group showed a marked increase of PCNA labeling index. 4. Wherease the calcium gradient was normal in the sham-operated and castrated group, it was distorted in the testosterone-replacement castrated group. Calcium deposition was increased through all layers of the epidermis and the calcium gradient disappeared in the testosterone-replacement castrated group. 5. Normal looking membrane structure was observed in the sham-operated and castrated group, but a membrane structure which appeared fragmented, incomplete lipid bilayer structures and prominent dilatation of lacunar domains were observed only in the testosterone-replacement castrated group. CONCLUSION: From the above results, it is concluded that there is a functional alteration of the epidermal barrier induced by testosterone, including the formation of an abnormal cornified envelope and also incomplete lipid synthesis.

Distribution Patterns of Involucrin in the Stratum Corneum of the Normal and Psoriatic Artificial Skins / 대한해부학회지

Cornified envelope is highly insoluble structure formed beneath the plasma membrane during terminal differentiation of keratinocytes and is stabilized by cross linking of various proteins, including involucrin, loricrin, and cornifin. Psoriasis is a chronic skin disease characterizing inflammatory reaction and hyperproliferation of keratinocyte. There are some differences in involucrin immunolabelling in stratum corneum between normal and psoriasis epidermis. Labelling was convergent to cornified envelope in psoriasis skin but throughout cytoplasm in normal skin. To compare terminal differentiation patterns of normal and psoriasis keratinocytes, we reconstructed normal and psoriatic artificial skin by using primary cultured keratinocytes from normal and psoriasis skin and then performed immunogold labelling for involucrin in stratum corneum. Psoriatic artificial skin had thin and poorly organized corneal layer. Immunogold labelling for involucrin revealed same pattern of that in vivo by showing throughout cytoplasm in lower layer but convergent cornified envelope in upper layer. Compared with psoriatic artificial skin, normal artificial skin had well organized and thick stratum corneum. Involucrin labelling was throughout cytoplasm in most of corneal layer but convergent to cornified envelope in some uppermost cells. Even though some cells show convergent pattern in normal artificial skin, absolute number of this pattern was no lesser than in artificial psoriatic skin because of normal artificial skin had thick stratum corneum. This result showed there was no difference in involucrin distribution in terminal differentiation of normal and psoriasis keratinocytes in organotypic culture model. It is concluded that although well organized multiple corneal layers are formed in normal artificial skin, they can not reach to full maturation of cornified envelope, and difference of involucrin localization in cornified envelope of psoriasis epidermis is related with not peculiarities of the cells but rapid growing in vivo.

bcl-2 and Involucrin Expression in Basal Cell Carcinoma and Squamous Cell Carcinoma / 대한피부과학회지

BACKGROUND: The histologic distinction between basal cell carcinoma(BCC) and squamous cell carcinoma(SCC) is sometimes difficult, but clinically important because the risk of progressive disease is significantly higher with SCC than BCC. OBJECTIVE: The purpose was to investigate the usefulness of bcl-2 and involucrin staining in distinguishing BCC from SCC. METHODS: We studied 10 cases of BCC and 10 cases of SCC with monoclonal antibodies for bcl-2 and involucrin. RESULTS: Five of 10 cases of BCC stained with bcl-2, but none of SCC stained. Only 2 of 10 cases of BCC stained weakly with involucrin, but all 10 cases of SCC stained moderately or strongly. CONCLUSION: A panel of antibodies for bcl-2 and involucrin may be useful in distinguishing BCC from SCC. We might speculate that involucrin is a more useful marker because it is moderately to strongly positive for all cases of SCC while weakly positive for only 2 of 10 cases of BCC.

Change of Stratification of Three Dimensional Culture by Gingival Keratinocytes & Fibroblasts / 대한치주과학회지

Epithelial-mesenchymal interaction plays a important role in cell growth and differentiation. This interaction is already well known to have an importance during the organ development as well as cell growth and differentiation. However, in vitro experimental model is not well developed to reproduce in vivo cellular microenvironment which provide a epithelial-mesenchymal interaction. Because conventional monolayer culture lacks epithelial-mensenchymal interaction, cultivated cells have an morphologic, biochemical, and functional characteristics differ from in vivo tissue. Moreover, it's condition is not able to induce cellular differention due to submerged culture condition. Therefore, the aims of this study were to develop and evaualte the in vitro experimental model that maintains epithelial-mesenchymal interaction by organotypic raft culture, and to characterize biologic properties of three-dimensionally reconstituted oral keratinocytes by histological and immunohistochemical analysis. The results were as follow; 1. Gingival keratinocytes reconstituted by three-dimensional organotypic culture revealed similar morphologic characteristics to biopsied patient specimen showing stratification, hyperkeratinosis, matutation of epithelial architecture. 2. Connective tissue structure was matured, and there is no difference during stratification period of epithelial 3-dimensional culture. 3. The longer of air-exposure culture on three-dimensionally reconstituted cells, the more epithelial maturation, increased epithelial thickness and surface keratinization 4. In reconstitued mucosa, the whole epidermis was positively stained by anti-involucrin antibody, and there is no difference according to air-exposured culture period. 5. The Hsp was expressed in the epithelial layer of three-dimensionally cultured cells, especially basal layer of epidermis. The change of Hsp expression was not significant by culture stratification. 6. Connexin 43, marker of cell-cell communication was revealed mild immunodeposition in reconstitued epithelium, and there is no significant expression change during stratification. These results suggest that three-dimensional oragnotypic co-culture of normal gingival keratinocytes with dermal equivalent consisting type I collagen and gingival fibroblasts results in similar morphologic and immunohistochemical characteristics to in vivo patient specimens. And this culture system seems to provide adequate micro-environment for in vitro tissue reconstitution. Therefore, further study will be focused to study of in vitro gingivitis model, development of novel perioodntal disease therapeutics and epithelial-mensenchymal interaction.

Immunohistochemical Study of Expression of Involucrin, Loricrin, Filaggrin and Bcl-2 in Psoriasis / 대한피부과학회지

BACKGROUND: The pathogenesis of psoriasis remains uncertain. It is known that a variety of factors take a role in its pathogenesis. One of them is the alteration of keratinocytes differentiation. The terminal differentiation of keratinocytes includes the process of the synthesis of proteins such as involucrin, filaggrin, loricrin and cornifin, and produce keratohyaline granules and a structure termed cornified cell envelope finally. And the terminal differentiation of keratinocytes is known as a process of apoptosis, programmed cell death. OBJECTIVE: In this study, we tried to clarify the pathogenetic mechanisms of psoriasis by comparing the expression patterns of several proteins(involucrin, loricrin, filaggrin) associated with keratinocyte differentiation and of bcl-2 protein, known as inhibitor of apoptosis, between lesional and non-lesional psoriatic skin. RESULTS: The results were summarized as follows, firstly early expression of involucrin in lower epidermis, secondly no or reduced expression of filaggrin and loricrin in upper epidermis and lastly no expression of bcl-2 in basal layer of psoriatic skin. CONCLUSION: This study clarified that the accelerated terminal differentiation, the shortening of cell-cycle of keratinocytes, and the increased turnover of keratinocytes may be involved in the pathogenetic role of psoriasis.

The Measurement of Double Staining for Senescence Associated-beta-Galactosidase Activity and Keratin 10 or Involucrin in Monolayer and Organotypic Cultured Keratinocytes / 대한해부학회지

This experiment developed the methodology of double staining for senescence associated-beta-galactosidase (SA-beta-gal) activity and keratin 10 (K10) or involucrin. To prove the usefulness of the double staining, the author investigated the relationship between senescence and differentiation in monolayer and organotypic cultured keratinocytes. The results were as follows: K10 and involcrin together with SA-beta-gal were doubly stained in most of monolayer cultured keratinocyte. This fact indicated that the senescence and differentiation had simultaneously occurred in the same keratinocyte. In spite of the advantages to preserving structures, the paraffin specimen was not suitable for double staining because of the limitation of SA-beta-gal reactivity. Although the cryosectioned specimen did not have the morphology as good as the paraffin specimen, it was suitable for double staining due to the goodness of SA-beta-gal reactivity. Double staining well reflected the disturbances of senescence and differentiation which could be caused by deranged organizations of the organotypic cultured skin. The organotypic cultured skin which showed deranged organizations such as stratified basal layer, no typical cell features in each epdermal layer, and wide intercellular spaces had SA-beta-gal activity in epidermis and K10 or involucrin reaction in basal cell. But the skin which showed well arranged organizations resembling in vivo skin had no SA-beta-gal activity and no K10 or involucrin reaction in basal cells. In conclusion, it might be suggested that the double staining for SA-beta-gal activity and K10 or involucrin could be used for detecting the extent of senescence and differentiation in the same cell.

Replicative Senescence and Differentiation Properties of Reconstituted Skin and Monolayer Human Keratinocytes in Vitro / 대한해부학회지

This experiment tried to elucidate the characteristics of senescence and differentiation in the reconstituted skin and the monolayer cultured human keratinocytes in vitro, respectively. While the keratinocytes were cultivated from undifferentiated state to completely senescent and differentiated, the monolayer cultured cells of every passage were doubly stained with SA-beta-gal initially, then keratins or involucrin. We also performed the SA-beta-gal enzyme staining and the immuno-reaction such as keratins or involucrin in the reconstituted skin. The results were as follows: Lack of reactivity against SA-beta-gal in the reconstituted skin indicated that there was no senescence occurred. The reconstituted skin showed decreased expression of K10 and preceded expression of involucrin compare to in vivo skin. Nevertheless, the reconstituted skin which did not express the K10 or involucrin in the basal cell maintained the differentiation system similar to that of in vivo skin. On the other hand, the monolayer cultured keratinocytes showed a thoroughly different pattern in the senescent and differentiating process. SA-beta-gal was colocalized with K10 or involucrin in the cells of high percentage ratio by the double staining method, and this indicated that the senescence and differentiation in the kratinocytes were simultaneously progressed. Reaching the nearer stage leading to the cell death, the cells choosed the one of senescence or differentiation pathway. It was supported by the fact that the percentage index of double staining together with SA-beta-gal and involucrin was lower at passage 5 than passage 1~4. The SA-beta-gal's reactivity was maximally reached at passage 4 and the involucrin maximally reached at passage 5. These trends suggested that the senescence was preceded by the differentiation. In conclusion, the reconstituted skin maintained only the differentiation system without the cell senescent process similar to the in vivo while the senescent and differentiating events were simultaneously processed in the monolayer cultured keratinocytes.

Clinicohistopathologic Findings in Keratoacanthoma and its Immunohi-stochemical Study of Ki-67, p53, bcl-2 and Involucrin Protein Expression / 대한피부과학회지

BACKGROUND: Keratoacanthoma(KA) is common, benign cutaneous tumor that is most likely derived from hair follicle cells, and most often occurs on sun-exposed sites in light-skinned persons of middle age or older. Some authors believed that keratoacanthoma is a variant of squamous cell carcinoma(SCC), which it often resembles clinically and histopathologically. So, the distinction between KA and SCC is still debatable and a matter of speculation. OBJECTIVE: The purpose of this study was to investigate the clinicohistopathologic findings of KA and its expression patterns, compared with SCC, of immunohistochemical staining using Ki-67, p53, bcl-2, and involucrin. METHODS: This clinicohistopathologic study included 20 cases that had confirmed to KA. We performed the immunohistochemical staining with Ki-67, p53, bcl-2 in 14 and with involucrin in 13 KAs. Ki-67, p53, bcl-2, and involucrin staining was also performed in 6 SCCs. RESULTS: All of KAs were solitary lesions. The male to female ratio was 1.2:1. The average age was 63.315.1 years and 11 of 20(55.5%) developed in sixth and seventh decades. The site of predilection were sun-exposed areas(85%) such as face, forearm, neck. Histologically, all of KAs were fully-developed lesions, and 17 of 20(85%) were dome or berry-shaped type II KAs. 17 of 20(85%) KAs showed exo-endophytic growth pattern. Common histologic findings in this study were horn-filled crater formation(80%), epidermal collarette(85%), epidermal proliferation in the perilesional area and the base of crater(100%), lateral extension tendency(80%), individual keratinization(75%), intraepithelial neutrophilic microabscess(65%), and eosinophilic glassy appearance in kertinocytic cytoplasm(95%). In immunohistochemical study using Ki-67, p53, bcl-2, and involucrin, there were no significant differences between KA and SCC except of the distribution pattern of Ki-67 positive cells in tumor. Ten of 14(71.4%) KAs revealed the marginal pattern, whereas no SCCs showed marginal pattern in Ki-67 staining. CONCLUSION: KA is a rapidly growing, cutaneous tumor that most often occurs on sun-exposed sites in sixth and seventh decades. Our results showed that KA is almost similar to SCC immunohistochemically, we suggest that KA is a type of SCC. And also, the characteristic distribution pattern of Ki-67 positve cells is helpful in making differentiation between KAs and SCCs.

Expression Patterns of Cytokeratin and Involucrin in the Epidermis of the Artificial Skin Reconstructed by Cultured Cells / 체질인류학회지

To investigate differentiation and growth process of keratinocytes in organotypic cultured skin, we carried out immunohistochemical studies for cytokeratin (CK) 10, 14, 16, 17 and involucrin in the cultured skin. In normal skin CK14 and CK10 were detected in the basal and all suprabasal layer, respectively, whereas in artificial skin CK14 was detected up to the middle of spinous layer but CK10 expressed from the middle of spinous layer. The detection of involucrin in normal skin was from the upper spinous layer but found from lower spinous layer in the artificial skin. Both CK16 and CK17 did not expressed in in vivo skin but expressed weakly in the spinous layer of artificial skin. It is therefore concluded that the characteristics of basal cell were maintained in the several, lower layers of the sartificial skin. The growth and differentiation steps of the skin were similar to those of in vivo although differences were seen in the expression level.

Expression of Involucrin and Filaggrin in Various Skin Disorders: Immunohistochemical Study / 대한피부과학회지

BACKGROUND: The cornified cell envelope (CE) is a unique structure found in the terminal differentiation of the skin. The precursor proteins of the CE are composed of many candidate structural proteins, among which invalucrin and filaggrin are important ones to participate in the complicated process of forming, the complex structure. OBJECTIVE: The purpose of this study was to evaluate the usefulness of expression of involucrin and filaggrin as markers of terminal differentiation in various skin disorders including tumors. METHODS: Immunohistochemical studies were performed in the formalin-fixed, paraffin-embedded skin samples of non-tumors (41 cases) and tumors (43 cases).

Expression of cytokeratins and involucrin in cultured human keratinocytes / 대한해부학회지

To evaluate the maturation and differentiation state of cultured keratinocytes, the author investigated expression of differentiation markers in cultured keratinocytes. The specimens were divided into three experimental groups, 3rd passage keratinocytes cultured in serum free media (3rd SFM group), 6th passage keratinocytes cultured in serum free media (6th SFM group) and 3rd passage keratinocytes cultured in DMEM (DMEM group). CK14, marker of basal layer, expressed in all groups. The expression was localized and condensed in the SFM groups but spreade in the DMEM group. Most of the cells in both SFM groups were positive but a few cells in DMEM group were also positive. CK10, marker of initiation of differentiation, expressed weakly in DMEM group but there was no expression in both SFM groups. Involucrin, marker of terminal differentiation, expressed weakly in DMEM group but there was no expression in both SFM groups. CK16 and 17, markers of fast turnover of keratinocytes, were not expressed in SFM groups. Weak positive reactions were observed in DMEM group. With these results the authors concluded that the keratinocytes from 3rd passage to 6th passage, cultured in serum free media with calcium less than 0.1 mM, had highly homogeneous basal cell characteristics.

Immunohistochemical Study for Differentiation of Human Middle Ear Cholesteatoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Human epidermis is a continuously dividing tissue, in which keratinocytes gradually differentiate and mature while moving from basal cells to suprabasal cell layers. Epidermal homeostasis is maintained by a delicate balance between proliferation and terminal differentiation. Cholesteatoma is characterized by the presence of a squamous epithelium invading the middle ear, which is believed to have hyperproliferative properties. The aim of this study is to determine whether the hyperproliferative character of cholesteatoma is associated with differentiation of basal cell or suprabasal cell layers. MATERIALS AND METHODS: Using immunohistochemical techniques, we investigated the reaction pattern of monoclonal antibody to involucrin and filaggrin as differentiation markers in the cholesteatoma matrices which were harvested during surgery. For the control, the same immunohistochemical study was also done in deep meatal skin and retroauricular skin during the same surgery. RESULTS: The immunostaining intensity of filaggrin at suprabasal cell layers was higher in cholesteatoma than in retroauricular skin and deep meatal skin. The immunostaining intensity of involucrin at suprabasal cell layers was higher in cholesteatoma and deep meatal skin than in retroauricular skin. CONCLUSION: This result represents that the epidermal cells in cholesteatoma at suprabasal layers actively differentiate more than the epidermal cells in retroauricular skin. So this study suggests that hyperkeratinization in cholesteatoma might be due to altered differentiation of suprabasal keratinocytes. Furthermore, this study reveals that the deep meatal skin has unusual hyperproliferative behavior in contrast to the retroauricular skin.

Development of Psoriasis Model in Vitro / 대한해부학회지

Psoriasis is a disease caused by hyperproliferation of keratinocytes. Pathogenesis of psoriasis is still unclear, but many reports suggest that psoriatic keratinocytes themselves may have some factors of pathogenesis. The author developed artificial psoriatic skin by culturing keratinocytes of psoriasis skin over collagen lattice which was constructed with collagen and normal fibroblasts. After the keratinocytes had grown to full layers of stratification, expression patterns of differentiation marks and ultrastructural changes were investigated by immunohistochemistry and electron microscope. The results were very similar to those of psoriasis skin in vivo as follows. Cytokeratin (CK)10, marker of initiation of differentiation of keratinocytes, was expressed in the spinous layer. CK14, marker of basal cells of stratified squamous epithelium, was expressed in the basal and spinous layer. CK16 and CK17, markers of fast turnover of squamous epithelium, were expressed in the spinous layer. Involucrin, marker of terminal differentiation of squamous epithelium, was expressed weakely over the lower spinous layer. In immuno electron microscopical study, involucrin was expressed but confined to cornified cell envelops in the horney layer. Mitochondria, rER and ribosomes were abundant in the basal layer. They continued to appear in the upper spinous layer but intermediate filaments were scarce. Keratohyalin granules were visible in some parts of the granular layer zone, but the granules were smaller and fewer. In the horney layer, cells were thicker than normal and there were many lipid droplets within the cells. Intercellular spaces were enlarged at the basal layer but disappeared in the upper spinous layer. In these results, non systematic expression of differentiation markers and ultrastructural changes suggest that psoriasis is a disease caused by hyperproliferation of keratinocytes concurrent with unstable maturation and degeneration. Artificial psoriatic skin, in exclusion of systemic or dermal effects, showed very similar results with psoriasis skin in vitro. So it was concluded that psoriasis keratinocytes had some factors of pathogenesis and this kind of model on artificial psoriatic skin can be used for further studying of psoriasis.

A study on cytokeratin and involucrin expression in the epidermis of nevus sebaceus / 대한피부과학회지

Thirty two cases of nevus sebaceus were studied by immunohistochemical staining employing three anticytokeratin antibodies(34bE, 34bB, CAM 5.2) and anti-involucrin antibody in order to clarify the biochemical characteristics of the covering epidermis of nevus sebaceus. An attempt was made to compare the expression pattern of these proteins in the epidermis of nevus sebaceus with that in normal skin and in epidermal nevus. Serial sections in all cases were also stained with PAS in attempt to correlate these protein expression with the amount of glycogen in the epidermis of nevus sebaceus. The following results are obtained. 1. The expression of cytokeratin and involucrin in the epidermis of nevus sebaceus was changed as the age of the lesions increased, but we could not identify a uniform pattern according to the age of lesions. 2. Several CAM 5.2 positive cells were found in the basal layer of the epidermis of nevus sebaceus lesion obtained from patients over 10 years of age. 3. The expression of cytokeratin and involucrin did not show any correlation with glycogen content. These results suggest that the covering epidermis of the lesion of nevus sebaceus may not be nevoid proliferation of epidermal nevus.

Involucrin Expression in Epidermal Tumors / 대한피부과학회지

Involucrin is a recently recognized structural component of mature squamous epithelial cells and is considered as a marker of normal eratinocyte differentiation and ma.turation. In this study peroxidase-antiperoxidase techniques were used to assess involucrin expression in histologic sections of normal skin and a variety of epidennal tumors including squamous cell carcinomas(25 cases), keratoacanthomas(11 cases), basal cell carcinomas(20 cases), trichoepitheliomas(5 cases), Howens diseases(12 cases), arsenic keratoses(10 cases), actinic keratoses(10 cases) and Pagets diseases(2 cases). The results were as follows : l. In normal skin, the upper third of the viable epidermis showed diffuse cytoplasmic staining for involucrin. In hair follicles, the lower area of inner root sheath and inner area of the outer root sheath stained positively. The sebareous glands did not stain, but the ducts of sebaceous glands were positive. 2. Keratoacanthomas showed a relatively homogeneous staining pattern for inirolucrin ', all cells except basal cells stained with mild to moderate intensity. In contrast, squamous cell carcinomas disclosed a highly irregular involucrin staining pattern with marked variation in staining intensity from cell to cell. 3. Basal cell carcinomas were negative for involucrin except squamous horn cysts, and the epidermis overlying basal cell carcinomas showed the field effect, that is, the epidermis overlying the tumors exhibited diffuse, homogeneous positive staining of cells in all layers of the epidermis. 4. ln trichoepitheliomas, the involucrin reactivity was negative as in basal cell carcinoma.s, but the field effect was not observed. 5. In Elowens disease, actinic keratosis, arsenic keratosis and Pagets disease, the positivit.y for involucrin staining extended deeper into the stratum malpighii than was observed wit,h normal epidermis. And areas showing irregular patchy pattern of involucrin staining were considered to have the potentiality of malignant invasive change much more than the negative or homogeneous areas. Paget's cells were negative for involucrin as the adjoining keratinocytes in the lower portion af epidermis.