银屑病患者皮损表皮生长因子及其受体的检测

用抗表皮生长因子（ＥＧＦ）多克隆抗体、抗表皮生长因子受体（ＥＧＦＲ）单克隆抗体及ＡＢＣ免 疫酶标技术，对２０例寻常型银屑病患者皮损及１０例正常人皮肤进行观察。结果表明：①正常人皮肤及 银屑病非皮损区皮肤ＥＧＦ及ＥＧＦＲ主要分布在表皮基底细胞层及基底层上部。②银屑病进行期皮损 ＥＧＦ及ＥＧＦＲ分布于表皮各层，表皮中、上层含量明显升高。③经有效治疗消退期皮损ＥＧＦ及ＥＧＦＲ 从角质层开始消退，分布趋于正常。提示ＥＧＦ及ＥＧＦＲ对银屑病皮损角肮细胞过度增殖及异常分化起 重要作用。     

Role of the epidermis and other epithelia in wound healing: selected concepts

In its normal state, the epidermis is a complex organ in which several cell types, including keratinocytes, Langerhans cells, and melanocytes coexist and interact in complex ways about which little is currently known. The keratinocytes undergo, first, cell division in the deeper layers of the stratum malpighii, then active migration and differentiation to rearrange themselves in the stratum granulosum for final differentiation into keratinized cells. The process by which these cells migrate in an orderly fashion from the undulating dermal-epidermal interface to the flat interface with the keratinized layer is not understood. It is known that few of the basalar cells are undergoing replication at any one time, so that a large, reserve “G^O” pool of cells exists.When there is an injury to the epidermis so that, for example, a portion is removed without damage being done to the dermis, the cell migration pattern changes, so that an increased number of keratinocytes is produced to replace those that have been damaged, killed, or removed. The kinetics of this process is, however, poorly characterized. Also, in states of inflammatory or metabolic injury to the epidermis, there are marked changes, again rather poorly characterized, in epidermal cell migration patterns, which often produce the parakeratotic crust and scale characteristic of many of those pathologic states. Finally, there are diseases—of which the prototype is psoriasis—in which there is a marked change in cellular proliferation and differentiation that, itself, constitutes or produces the major manifestations of the disease. Although the kinetic considerations in psoriasis have been well studied, the studies are difficult to interpret and questions regarding them abound. Recently this problem in nonwounded skin has been reviewed and critically analyzed by Gelfant.¹We face a large number of uncertainties about the division, migration, and differentiation of keratinocytes in normal, damaged, or pathologically altered epidermis. Further, there are many unanswered questions regarding other epidermal cell types, their interactions with each other and with keratinocytes, and the chemical and other signals that mediate those interactions. Thus, the problem of analyzing the role of the epidermis in wound healing, in which there is damage to the dermis as well as to the epidermis, becomes difficult, if not insolvable. Nevertheless, there are rather extensive experimental data regarding several aspects of the problem, including changes in cell morphology, mechanisms of cell migration, kinetics and patterns of cell migration, and factors controlling cell division. Some of these data on the role of the epidermis in wound healing will now be briefly examined.     

银屑病患者表皮及真皮中Bcl-X、Bcl-2、Bax表达的免疫组化研究

目的 探讨银屑病患者细胞增殖与凋亡的调节。方法 用免疫组化ＳＰ法检测银屑病皮损及非皮损中Ｂｃｌ－Ｘ、Ｂｃｌ－２、Ｂａｘ的表达情况。结果 银屑病皮损中,Ｂｃｌ－Ｘ在表皮各层、真皮炎症细胞及血管内皮的表达均较正常明显增高;Ｂａｘ在颗粒层与棘层的表达轻度增高。上述异常在非皮损中已经部分存在,且隍未完全恢复正常。而Ｂｃｌ－２表达与正常相似,局限于基底层黑素细胞,角质形成细胞未是性。结论 银屑病中角质形成细     

Psoriasiform architecture of murine epidermis overlying human psoriatic dermis transplanted onto SCID mice

Preliminary observations in a xenogeneic SCID mouse transplantation model indicated that murine epidermis overgrows human dermis from psoriatic skin but not that form normal skin. To investigate the effect of peripheral blood mononuclear cells on the differentiation of murine keratinocytes, we transplanted involved and uninvolved full-thickness skin from patients with psoriasis onto SCID mice and followed this with repeated subcutaneous injections of cells suspended in patient serum. After 6 weeks grafts were analysed morphologically and immunohistochemically. The epidermis in grafts from clinically uninvolved skin appeared normal. The persistence of a psoriasiform epidermis was noted in all grafts from affected sites despite a lack of lymphocytic infiltration. Staining for human and mouse MHC class I antigens revealed the murine origin of keratinocytes forming the psoriasiform epidermis, while the human dermis was retained. Our observations indicate that the defect underlying the pathogenesis of psoriasis is most likely located in the dermal rather than the epidermal compartment. This xenogeneic transplantation model may be useful for future studies of the pathogenesis and treatment of psoriasis.     

Morphology of aged skin

Despite an overall thinning of the epidermis and focal areas of cytologic atypia, there was no morphologic evidence that the protective function of this tissue was compromised by age. The characteristic morphologic markers associated with the keratinization process were not altered either in appearance or in amounts. A well-formed stratum corneum was present, suggestive that barrier ability is not compromised in senile skin. Whereas alterations in the aged epidermis are slight, the dermal-epidermal changes are marked and have greater physiologic consequences. The major change is a relatively flat dermal-epidermal junction because of retraction of the epidermal papillae as well as the microprojections of basal cells into the dermis. This flattening results in a more fragile tissue less resistant to shearing forces. Retraction of the epidermal downgrowths may also explain the loss in proliferative capacity associated with the aged epidermis. The major alterations in the aged dermis concern the architecture of the collagen and elastin networks. Both fibrous components appear more compact because of a decrease in the voids or spaces between the fibers; the spaces resulted from a loss of ground substance. Collagen bundles appear to unravel, and the individual elastic fibers show signs of elastolysis. The net effect of these fibrous rearrangements and alterations is a dermis that is less stretchable, less resilient, more lax, and prone to wrinkling.     

Effects of lithium carbonate (Li2CO3) on in-vitro-cultured normal human skin explants

The early morphological changes induced by lithium carbonate, a well-known psoriasis-provoking drug, were studied on cultured skin. Normal human skin from patients undergoing mastectomy was cultured in the presence of 3 mM, 6 mM and 10 mM of Li2CO3 for 4 days. The morphological changes were then evaluated by three observers in a blind manner and their reports were matched and collated. The cultured skin in the presence of Li2CO3 showed cell crowding of keratinocytes in the lower part of the epidermis, indicating epidermal hyperplasia. Another striking finding was intercellular oedema and vacuolar alteration with formation of small cavities in the upper dermis. There was no evidence of parakeratosis or any other histological characteristic of psoriasis, except hyperproliferation of the epidermis. Based on our knowledge of mechanisms of lithium action, we proposed two competitive explanations for its action on the epidermis: i) that lithium acts directly on dividing cells of the epidermis; and ii) that it acts indirectly by altering epidermal barrier function. Although we lack definite proof, we suggest that the observed morphological changes, in particular the non-specific stimulus to epidermal proliferation, are the primary events which initiate the process that will ultimately lead to the development of psoriasis in a predisposed patient.     

Immunohistochemical localization of lipocortins in normal and psoriatic human skin

The distribution of lipocortin I, a steroid-induced inhibitory protein of phospholipase A₂, was examined in normal and psoriatic human skin. Using immunoblotting analysis with specific antibody against human lipocortin I purified from human placenta, lipocortin I was detected as a 37 kDa protein in cultured epidermal cells, whole skin and epidermis. In the dermis and stratum corneum, lipocortin I was only weakly detectable by Western blotting. In contrast to normal skin, much less lipocortin I was detected by Western blotting analysis in psoriatic skin. Using immunoperoxidase immunohistochemical analysis, lipocortin I was demonstrated in the cytoplasm of keratinocytes in the upper and middle layers of the epidermis and in some infiltrating cells in the dermis in normal skin. In involved psoriatic skin, by contrast, lipocortin I was almost undetectable in the epidermis, although it was demonstrated in some infiltrating cells in the dermis. No immunostaining of lipocortin I was observed in the stratum corneum of normal or psoriatic skin. These results, together with the finding that phospholipase A₂ activity is higher in psoriatic epidermis than in normal epidermis, suggest that lipocortin I plays an important role in the regulation of differentiation and proliferation of epidermal keratinocytes.     

Vascular proliferation and angiogenic factors in psoriasis

Psoriasis is a common, chronic skin disorder characterized by hyperproliferation of the epidermis, inflammatory cell accumulation and increased tortuosity and dilatation of dermal papillary blood vessels. Research into the pathogenesis of psoriasis has concentrated mainly on the interplay between inflammatory cells and epidermal proliferation. Central to the proposed pathogenetic pathway are cytokines produced by activated keratinocytes, which are thought to induce both keratinocyte proliferation and lymphocyte migration. Cytokines also mediate upregulation of adhesion molecules on vascular endothelium which in turn permits lymphocyte recruitment. The close spatial relationship between altered microvasculature and epidermis is clearly important in psoriasis. Consequently, understanding the mechanisms underlying vascular changes is fundamental to an elucidation of pathogenetic mechanisms in psoriasis.     

银屑病皮损中γ干扰素的免疫组化分析

采用γ干扰素（ＩＦＮ－ ）单克隆抗体、双层ＡＰＡＡＰ染色法及显微分光光度测定技术对３０例银屑病患者皮损、１５例正常对照皮肤进行ＩＦＮ－ 抗原的测定。结果显示：除表皮基底层及表皮突下部 １～３层基层外，大量的ＩＦＮ－　抗原阳性染色弥漫分布于皮损全层表皮的角肮细胞间隙；正常对照皮肤的表皮中无明确的ＩＦＮ－　阳性反应；银屑病皮损表皮中ＩＦＮ－　的含量①与银屑病的活动性有关，进行期为２４．３８０８．２５０，静止期为１５．９５５　５．３２７（Ｐ＜０．０１）；②与皮损表皮中Ｔ细胞、ＨＬＡ－ＤＲ细胞的数量呈直线正相关（ｒ１＝０，６９４，ｒ２＝０．４３６，Ｐ＜０．０５）。     

Histologic features of paraneoplastic pemphigus.

BACKGROUND--We describe the histopathologic features of paraneoplastic pemphigus, a recently described autoimmune mucocutaneous disease associated with neoplasia. Complete evaluation for paraneoplastic pemphigus requires identification of the characteristic mucocutaneous eruption, tissue specimens for routine histologic and direct immunofluorescence evaluation, and identification of circulating autoantibodies with a unique specificity. Immunoprecipitation from keratinocytes reveals a characteristic complex of four proteins with the circulating antibodies. Various neoplasms have been identified in patients with paraneoplastic pemphigus. OBSERVATIONS--We reviewed 16 skin and oral mucous membrane biopsy specimens from six patients with paraneoplastic pemphigus confirmed by fulfillment of all criteria. Major features include epidermal acantholysis, suprabasal cleft formation, dyskeratotic keratinocytes, vacuolar change of the basilar epidermis, and epidermal exocytosis of inflammatory cells. Seven (44%) of 16 specimens displayed a unique combination of suprabasal acantholysis and dyskeratotic keratinocytes throughout the epidermis. These histologic findings correspond to those of the characteristic clinical lesions that are described as having features of pemphigus and erythema multiforme. CONCLUSIONS--Paraneoplastic pemphigus represents a unique clinical, histologic, and immunologic disease characterized by autoantibody production to desmoplakin I and desmoplakin II, bullous pemphigoid antigen, and, possibly, other antigens in the desmosomal complex. Recognition of the histologic features should prompt immunopathologic confirmation and evaluation for an occult neoplasm.     

In situ localization of IFN-gamma-positive cells in psoriatic lesional epidermis.

Interferon-gamma (IFN-gamma) is believed to be an important mediator in the cytokine cascade of psoriasis. Lesional T cells in the epidermis may play a role in psoriasis. We examined whether IFN-gamma-producing T cells were present in the epidermis of psoriasis in situ by immunohistochemical techniques. Mixtures of CD4+ T cells and CD8+ T cells were found to be present in the papillary dermis and the epidermis of the psoriatic lesions. CD8+ T cells seemed to be dominant in the epidermis. Considerable amounts of IFN-gamma-positive cells were detected in infiltrates of the papillary dermis. IFN-gamma-positive cells were found to be present in the epidermis. The pattern of IFN-gamma staining appeared to be a combination of intracellular staining in mononuclear lymphoid cells and extracellular deposition in the surrounding areas. The staining was considered to be highly specific because it could be completely blocked by preabsorption with recombinant IFN-gamma. Our data suggest that psoriatic epidermal T cells produce and secrete IFN-gamma within the lesion and that these T cells are involved in the pathogenesis of psoriasis.     

Plaque psoriasis vs. atopic dermatitis and lichen planus: a comparison for lesional T-cell subsets, epidermal proliferation and differentiation

BACKGROUND: T-cell infiltration in plaque psoriasis has recently been an important subject of investigation. Interestingly, comparative analyses of the disease-specific composition of the lesional T-cell infiltrate in plaque psoriasis and other inflammatory dermatoses have only sparsely been performed. OBJECTIVES: To compare plaque psoriasis vs. atopic dermatitis and lichen ruber planus with respect to T-cell subsets, epidermal proliferation and keratinization. PATIENTS AND METHODS: Biopsies were taken from untreated lesional skin of patients, six with psoriasis, six with atopic dermatitis and six with lichen planus. T-cell subsets (CD4+, CD8+, CD45RO+, CD45RA+, CD2+, CD25+), an epidermal proliferation (Ki-67) and a keratinization marker (K10) were stained immunohistochemically and quantified using image analysis. RESULTS: The high number of CD8+ T cells (52 +/- 13 cells mm(-1)) found in the psoriatic epidermis was not found in the epidermis of atopic dermatitis (9 +/- 4), nor in the epidermis of lichen planus (34 +/- 10). The other T-cell subsets in the epidermis and dermis showed no statistically significant differences between psoriasis and atopic dermatitis. In contrast to the limited presence of CD4+, CD8+ and CD2+ in the psoriatic dermis (110 +/- 19, 27 +/- 9, 127 +/- 41, cells mm(-1), respectively), more impressive numbers of these cells were observed in the dermis of lichen planus (300 +/- 53, 144 +/- 38, 272 +/- 48, respectively). CD45RO+ memory effector T-cell counts were significantly higher in the epidermis of lichen planus (39 +/- 10) than in psoriasis (19 +/- 5). Psoriatic epidermis proved to have major keratinocyte hyperproliferation (247 +/- 26 cells mm(-1) lamina basalis), as compared with atopic dermatitis (134 +/- 15) and lichen planus (128 +/- 20). Furthermore, a marked decreased expression of keratin 10 was observed in psoriasis (41% of epidermal area) contrary to atopic dermatitis (70%). CONCLUSIONS: Psoriatic epidermis exhibits a pronounced CD8+ epidermotropism with accompanying epidermal hyperproliferation and abnormal keratinization, which changes are only minimally expressed in atopic dermatitis and lichen planus. In plaque psoriasis, substantially fewer activated CD4+ and CD8+ T cells in the dermis and less CD45RO+ T cells in the epidermis are present in comparison with lichen ruber planus.     

Expression of Bmi-1 in epidermis enhances cell survival by altering cell cycle regulatory protein expression and inhibiting apoptosis

The polycomb group (PcG) genes are epigenetic suppressors of gene expression that play an important role in development. In this study, we examine the role of Bmi-1 (B-cell-specific Moloney murine leukemia virus integration site 1) as a regulator of human epidermal keratinocyte survival. We identify Bmi-1 mRNA and protein expression in epidermis and in cultured human keratinocytes. Bmi-1 is located in the nucleus in cultured keratinocytes, and in epidermis it is expressed in the basal and suprabasal layers. Adenovirus-delivered Bmi-1 promotes keratinocyte survival and protects keratinocytes from stress agent-mediated cell death. This is associated with increased levels of cyclin D1 and selected cyclin-dependent kinases, and reduced caspase activity and poly(ADP-ribose) polymerase (PARP) cleavage. Bmi-1 may be involved in the maintenance of disease state, as Bmi-1 levels are elevated in transformed keratinocytes, skin tumors, and psoriasis. The presence of Bmi-1 in suprabasal non-proliferative cells of the epidermis and within a high percentage of cells within skin tumors suggests a non-stem cell pro-survival role for Bmi-1 in this tissue. Based on the suprabasal distribution of Bmi-1 in epidermis, we propose that Bmi-1 may promote maintenance of suprabasal keratinocyte survival to prevent premature death during differentiation. Such a function would help assure proper formation of the stratified epidermis.     

Electron microscopy of the effects of dithranol on healthy and on psoriatic skin

The fine structure of healthy and of psoriatic skin was studied after dithranol irritation. Following a minimum erythematogenic or a moderate-to-considerable irritant reaction of healthy skin with dithranol, all epidermal cell types were focally affected. The Langerhans' cells (LC) were most sensitive, reacting with strongly swollen mitochondria with broken cristae, and sometimes by forming branched and circular Birbeck granules. More often than is normal, the Birbeck granules showed continuity with the LC cytomembrane. Also, melanocytes were more sensitive than keratinocytes. Most of the more strongly affected keratinocytes became cytolytic with edemic cytoplasm, but scattered cells underwent dyskeratosis (apoptosis) resulting in colloid bodies in the upper dermis. High amounts of lipid droplets developed in the basal keratinocytes, LCs, melanocytes, and dermal cells. Lipid droplets also developed in the keratinocytes at the stratum granulosum/stratum corneum interface concomitantly with a decrease in keratohyalin. Ten days after challenge, keratohyalin granules were normal again, but otherwise many changes in epidermis persisted, with increased numbers of exocytic cells and LC-mononuclear cell contacts in the epidermis and immunocompetent cells crossing the dermal-epidermal junction. These findings indicate that an irritant reaction could predispose to sensitization via nonspecifically activated immunocompetent cells. A single half-hour contact treatment with dithranol caused negligible changes in the psoriatic skin, while 24 hours' occlusion caused moderate-to-massive changes in mitochondria of keratinocytes, resulting in giant perinuclear mitochondria with broken cristae. Dithranol affects all cell types in the skin and morphologically it cannot be concluded which effect is the important one in clearing the psoriatic lesions.     

Psoralen-UVA-treated psoriatic lesions. Ultrastructural changes

Psoralen-ultraviolet light (PUVA)-treated psoriatic lesions were studied for ultrastructural changes. In early stages of treatment, sunburn cells in the epidermis and bizarre giant cells in the dermis were more frequently observed. When clinical improvement was apparent, these changes had subsided. Dermal abnormality in long-term therapy consisted of a thick perivascular coat of amorphous substance. No abnormality was found in the epidermal keratinocytes in long-term therapy, except a clustering and giant cell formation of melanocytes, a heavy melanization of keratinocytes, and hyperkeratosis. Low-dose initiation and slow increment of both 8-methoxypsoralen and UVA is probably a reasonable regimen for benign dermatoses such as psoriasis because it will allow enough time for the skin to become more protected, while the therapeutic results are as satisfactory as in a high-dose schedule.     

The activity of fatty acid synthase of epidermal keratinocytes is regulated in the lower stratum spinousum and the stratum basale by local inflammation rather than by circulating hormones

The epidermal keratinocytes produce and secrete lipids to maintain the water barrier of the epidermis. To clarify the regulation of epidermal lipid synthesis, we investigated the hormonal effect on the activity of fatty acid synthase (FAS) of the keratinocytes, and the expression of FAS in the human skin. In cultured keratinocytes, the FAS activity, assayed by measuring the oxidation of NADPH, was slightly increased by hydrocortisone or testosterone, but not influenced by thyroid hormone, estrogen, progesterone or insulin. In immunohistochemical study of normal human epidermis, FAS was expressed strongly in the stratum granulosum and moderately in the uppermost layer of the stratum spinousum (SS), suggesting that fatty acid synthesis may increase during normal epidermal differentiation. In inflammatory disorders, such as psoriasis, lichen planus, and atopic dermatitis, FAS was also expressed in the lower SS and the stratum basale (SB), resulting in strong staining in the whole layers of the epidermis. Remarkable increase of FAS expression was only observed in the lower SS and the SB. Therefore, the activity of FAS in the epidermis may be regulated in the lower SS and the SB by local inflammation rather than by circulating hormones. In other components of the skin, FAS was strongly expressed not only in adipose tissue and sebaceous glands, which are known as active sites of lipid synthesis, but also in sweat glands, suggesting that the sweat glands can synthesize abundant fatty acids de novo.     

A new marker of epidermal differentiation associated with the membrane coating granules: characterization and applications to pathology.

A murine monoclonal antibody, BC12, was obtained after immunization against suprabasal human keratinocytes. In the epidermis of normal human skin, the antigen recognized by BC12 (BC12 antigen) is located at the apex of keratinocytes in the upper stratum spinosum and stratum granulosum but is absent in other layers. The BC12 antigen is also present in hair follicles. Immunoblotting performed on keratinocyte subpopulations confirmed the presence of the BC12 antigen in differentiated keratinocytes only. Two-dimensional immunoblotting showed that the BC12 antigen corresponds to a set of polypeptides with an apparent molecular weight of approximately 33kD. In keratinocyte cultures, the antigen is present only in stratified areas. The distribution of the BC12 antigen, as studied by indirect immunofluorescence and immunoelectron microscopy, and its presence in certain subcellular fractions of epidermal cells suggest that it is a component of membrane coating granules (MCGs) or that it is associated with these structures. Strikingly, in psoriasis, eczema and many other diseases, the BC12 antibody does not label the epidermis, but vessels in dermal papillae. The BC12 antibody may thus be a useful tool in the study of keratinocyte differentiation and MCG physiology, and, also, in pathology.     

Local effects of TL01 phototherapy in psoriasis

The mechanisms whereby narrowband ultraviolet B (UVB) (311-313 nm, TL01) phototherapy are effective in psoriasis may differ from those occurring in broadband UVB phototherapy. In the present study, changes in epidermal cells as a result of TL01 therapy were assessed in the skin of patients with psoriasis. The non-lesional skin of five subjects with plaque psoriasis was biopsied before and after a series of 12 whole-body TL01 treatments. Following appropriate staining of skin sections, the numbers of p53-positive keratinocytes, sunburn cells and Langerhans cells in the epidermis were counted. TL01 therapy induced a threefold increase in the number of p53-positive epidermal cells, a 12-fold increase in sunburn cells and a twofold decrease in Langerhans cells. The increase in epidermal p53 expression and apoptosis of keratinocytes together with the depletion of Langerhans cells in the non-lesional skin of psoriasis patients are likely to contribute to the effectiveness of TL01 phototherapy.     

Effects of gemfibrozil on in vitro cultured normal human skin explants

BACKGROUND: Several lipid-lowering agents, when given topically, show a profound effect on skin morphology. Because of low bioavailability of these drugs for keratinocytes, the incidence is extremely low clinically. The most appropriate way to study the effect of hypolipidemic drugs on keratinocytes is by artificial exposure of the skin to high drug concentrations. OBJECTIVE: To study the effects of gemfibrozil on the morphology of in vitro cultured normal human skin explants. As gemfibrozil induces barrier disruption by inhibiting epidermal sterologenesis, essential for a competent permeability barrier, it is interesting to investigate the morphologic changes associated with this phenomenon. Studying the epidermal changes induced by lipid-lowering agents is important, not only because it might lead to a better understanding of the effects of these drugs on keratinocytes, but as it might also unlock the door to a wider knowledge of the pathomechanism of disorders of cornification. METHODS: Normal human skin from patients undergoing mastectomy was cultured in the presence of 2, 5, and 10 mM of gemfibrozil for 4 days The morphologic changes were evaluated by three blinded observers. Their reports were matched and collated. RESULTS: The cultured skin in the presence of gemfibrozil showed cell crowding of keratinocytes in the lower part of the epidermis, indicating epidermal hyperplasia and increased proliferation. Intercellular edema with the formation of small cavities in the epidermis, intracellular edema, and vacuolar alteration of keratinocytes in the upper portion of the epidermis were also observed. The intensity of these changes tended to parallel the gemfibrozil concentration. Some dermo-epidermal detachments did not correlate with the gemfibrozil concentration, but rather with tissue characteristics peculiar to each explant. CONCLUSIONS: The morphologic changes caused by gemfibrozil to normal human skin were not characteristic of psoriasis, and included intracellular and intercellular edema in the upper portion of the epidermis and cell crowding, indicating epidermal hyperplasia in the lower portion of the epidermis. The present experimental study gives further support to the hypothesis that hypolipidemic drugs cause an initial break in the barrier function of the epidermis, followed by a physiologic epidermal response, aimed at barrier restoration. This rather nonspecific stimulus to epidermal proliferation may trigger psoriasis in predisposed patients.