Staining Of Keratinocytes Research Articles

A case of revertant mosaic-like normal-looking spots in a patient with erythroderma with IL36RN and CARD14 heterozygous mutations.

An 89-year-old Japanese woman presented with erythroderma associated with significant scaling. A histological examination showed acanthosis with hyperkeratosis and hyperkeratinization of the hair follicles. Genetic analyses using DNA from the peripheral blood revealed heterozygous mutations in IL36RN (c.115+6T>C) and CARD14 c.2648G>A (p.Arg883His). Based on these findings, we diagnosed her with erythroderma attributable to autoinflammatory keratinization disease. She then developed more than 30 small, round, well-defined, spots on her back and extremities that appeared histologically normal. We suspected that these spots might be revertant mosaicism. Immunohistochemical staining with p65, which is a component of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), revealed nuclear staining in epidermal keratinocytes in erythematous lesions, but not in the normal-looking spots. However, mutations in IL36RN and CARD14 unexpectedly persisted in the epidermis and dermis of the normal-looking spots.

Direct immunofluorescence (DIF) versus immunohistochemical (IHC) staining of complements and immunoglobulins (Ig) in pemphigus group.

Pemphigus is a group of bullous disorders of the skin characterized by the formation of autoantibodies present in the intercellular junction of the epidermis. Diagnosis is made by clinical, histopathological examination, and DIF. As DIF needs frozen sections, fluorescent tagged antibodies, UV light microscope for examination, and trained personnel, its non-availability makes a definitive diagnosis challenging. To evaluate the utility of IHC staining of complements and Ig in cases of Pemphigus. Twenty-six diagnosed cases of Pemphigus were stained by Peroxidase immunohistochemical method using monoclonal antibody to IgG, IgA, IgM, IgG4, C3, C4 d with DAB as chromogen. Pemphigus cases include twenty of pemphigus vulgaris (PV), four cases of pemphigus foliaceous (PF), and two of pemphigus vegetans (Pveg). Positivity was defined as the deposition of Ig and complements as distinct, continuous brown staining of keratinocytes at intercellular junctions. On IHC total of 20 PV 17 showed positivity (85%) for IgG, 11 (55%) C4d, 19 (95%) C3d, and 16 (80%) IgG4 deposits at the intercellular junction of the epidermis. All cases of PF showed a deposit of IgG, with three (75%) cases for IgG4, C3d, and C4d. Both cases of Pveg showed positivity for IgG and C4d while one case was negative for IgG4 and C3d. The overall IgG, C3, IgG4, and C4d expression for pemphigus was seen in 88%, 88%, 76.9%, and 61.5% of cases. The relation between these markers, combination of IgG and C3, was best related to each other ( P value = 0.80). The sensitivities for IgG, IgG4, and C3 were 77.8%%, 73%, and 73% resp. We conclude that IHC is a useful tool in the diagnosis of PV with the highest sensitivity of IgG and C3d. The combination of IgG and C3d could replace the DIF in almost all of our cases, so IHC on FFPE sections be used as an alternative method to DIF.

Detection of N-glycolyl-neuraminic acid-containing glycolipids in human skin.

Humans lack the enzyme that produces the sialic acid N-glycolyl neuraminic acid (Neu5Gc), but several lines of evidence have shown that Neu5Gc can be taken up by mammalian food sources and replace the common human sialic acid N-acetyl neuraminic acid (Neu5Ac) in glycans. Cancer tissue has been shown to have increased the presence of Neu5Gc and Neu5Gc-containing glycolipids such as the ganglioside GM3, which have been proposed as tumor-specific antigens for antibody treatment. Here, we show that a previously described antibody against Neu5Gc-GM3 is binding to Neu5GC-containing gangliosides and is strongly staining different cancer tissues. However, we also found a strong intracellular staining of keratinocytes of healthy skin. We confirmed this staining on freshly isolated keratinocytes by flow cytometry and detected Neu5Gc by mass spectrometry. This finding implicates that non-human Neu5Gc can be incorporated into gangliosides in human skin, and this should be taken into consideration when targeting Neu5Gc-containing gangliosides for cancer immunotherapy.

Expression of Interleukin-1ß and Interleukin-8 in Oral Potentially Malignant Disorders and Carcinomas.

Objective: To evaluate interleukin-1ß (IL-1ß) and interleukin-8 (IL-8) epithelial expressions in potentially malignant disorders of the oral mucosa as malignant predictive markers.Study design: About 55 tissues embedded in paraffin, comprising 15 oral lichen planus (OLP) lesions, 15 leukoplakias, 15 oral squamous cell carcinomas (OSCC), and 10 samples of normal oral mucosa were included in the study. IL-1ß and 8 expressions were assessed by immunohistochemistry using antibodies antihuman IL-1ß human (sc-7884, Santa Cruz® H-153) and antihuman IL-8 (ab7747, abcam®). The number of positive cells was compared using Student's t-test. Any p-value < 0.05 was considered statistically significant.Results: Nuclear and cytoplasmatic keratinocyte staining were positive for both cytokines in all study groups. However, a statistically significant decrease was observed within all cases compared to normal mucosa, both staining for IL-1β and 8. Moreover, IL-8 showed significant differences between OLP and leukoplakia, and when compared to OSCC.Conclusions: Oral epithelial expression of IL-1β and 8 seems to decrease when the malignant transformation of the oral mucosa increases.

Classification and Staging of Morgellons Disease: Lessons from Syphilis.

IntroductionMorgellons disease (MD) is a contested dermopathy that is associated with Borrelia spirochetal infection. A simple classification system was previously established to help validate the disease based on clinical features (classes I-IV).MethodsDrawing on historical and pathological parallels with syphilis, we formulated a more detailed staging system based on clinical features as well as severity of skin lesions and corresponding histopathological infection patterns, as determined by anti-Borrelia immunohistochemical staining.ResultsClinical classes I-IV of MD are further categorized as mild, moderate and severe, or stages A, B and C, respectively, based on histopathological findings. Stage A lesions demonstrated little or no immune infiltrates and little or no disorganization of cells; macrophages were not present, and hemorrhage was negligible. Extracellular isolated spirochetes and intracellular staining of keratinocytes in the lower epidermis was occasionally seen. Stage C lesions demonstrated positive staining of keratinocytes in the stratum basale and stratum spinosum and positive intracellular staining of macrophages for Borrelia. Aggregate Borrelia colonies were frequently encountered, hemorrhage was frequent, and intracellularly stained fibroblasts were occasionally seen. Stage B lesions demonstrated a pattern intermediate between Stages A and C.ConclusionThe enhanced staging system provides objective criteria to assess the severity of dermopathy in MD. Further studies are needed to determine the optimal treatment for MD based on this staging system related to Borrelia infection.

Epidermal expression of eotaxins and thymic stromal lymphopoietin in eosinophil rich dermatoses.

Eosinophils are seen in a number of dermatologic conditions. While the extent of their function in these diseases remains to be fully elucidated, pathogenic activity in bullous pemphigoid suggests a more significant role than previously thought. Several dermatoses have a fairly characteristic histologic morphology of eosinophil infiltration. We hypothesized that epidermal expression of eotaxins and TSLP would differ by disease, perhaps explaining the different histologic morphologies. We performed a retrospective study of eosinophil rich dermatoses to perform immunohistochemistry. We collected 49 specimens composed of bullous pemphigoid (n = 15), atopic dermatitis (n = 12), drug rash (n = 8), arthropod assault (n = 5), and non-bullous pemphigoid eosinophilic spongiosis (n = 5). We used lichen planus (n = 4) as a control for lymphocyte-mediated inflammation. TSLP was diffusely expressed in all epidermal samples, whereas eotaxins demonstrated a weaker staining. Eotaxins and TSLP demonstrated a gradientbetween basal and spinous keratinocytes. The correlation between overall basal keratinocyte and spinous keratinocyte staining of eotaxins and TSLP with the number of eosinophils demonstrated a significant correlation between eotaxin-1 (R = 0.404, P = 0.004), eotaxin-2 (R = 0.576, P < 0.001), and eotaxin-3 (R = 0.512, P < 0.001), but not TSLP (R = 0.164, P = 0.251). These remained significant after correcting for multiple comparisons. While we were unable to detect significant differences in epidermal expression of eotaxins and TSLP in various eosinophil rich dermatoses, we identified a significant correlation of spinous keratinocyte eotaxin staining with tissue eosinophilia. Our identification of a correlation of spinous keratinocyte eotaxin staining with tissue eosinophilia may provide insight into local eosinophil chemotaxis.

Expression of CDK6 in Oral Squamous Cell Carcinomas

Background:CDK6 is the key factor in regulation of the cell cycle and essential for passage into the G1 phase. It also plays an important role in the development of various tumors. In this cross-sectional study expression of the CDK6 protein in oral squamous cell carcinoma (OSCC) and healthy oral mucosa of controls was assessed to determine relations with malignant transformation and clinicopathologic factors.Method:A total of 60 samples, 45 from OSCCs and 15 from healthy tissue, underwent immunohistochemistry for CDK6. Nuclear and cytoplasmic staining of keratinocytes was considered as positive and the percentages of positive cells were calculated.Results:Expression of CDK6 was detected in 55.6% of OSCC samples (25 cases) and 13.3% of controls (2 cases), the difference being significant. Mean percentage of CDK6 stained cells was 24.2±29.3 in the OSCC cases and 4.33±2.1 in the control group, again statistically significant. No relationship was detected between CDK6 expression and clinicopathologic factors.Conclusion:Overexpression of CDK6 observed in OSCC points to a role for this protein in oral carcinogenesis.

The role of intradermal proliferation of T-cells in the pathogenesis of psoriasis

BACKGROUNDPsoriasis is a common immune-mediated chronic inflammatory disease of the skin and joints, affecting 1-3% of the population. It is generally accepted that the pathogenesis of psoriasis involves accumulation of effector T-cells within lymph nodes and their subsequent migration into the skin through the blood system. Here we provide evidence that psoriatic plaque itself may serve as a source of inflammatory T-cells.OBJECTIVEWe examined the intradermal proliferation of T-cells and the number of effector/memory (CD45RO+) T-cells in the skin of psoriatic patients at different periods of the disease.METHODSSkin samples were obtained from 41 patients with progressive psoriatic lesions; 18 of these patients also donated skin specimens during the remission of the disease. The control group consisted of 16 healthy subjects. Ki-67 immunohistochemical staining was applied to detect proliferating cells, CD3ε served as a T-cell marker, and CD45RA and CD45RO antibodies were utilized to discriminate between naive and effector/memory T-cells, respectively.RESULTSProgressive psoriatic lesions demonstrated Ki67 staining both in keratinocytes and in the CD3ε+ cells of dermal infiltrate. Median count of CD45RO+ cells per microscopic field was 15 in healthy controls, 59 in patients in remission and 208 in progressive psoriatic plaques. The observed differences demonstrated high level of statistical significance.STUDY LIMITATIONSLimited number of analyzed patients.CONCLUSIONProgressive phase of psoriasis is characterized by intradermal proliferation of T-cells. Spots of regressed psoriatic lesions contain high number of CD45RO+ cells, which are likely to render an immunological memory.

Gamma-interferon-inducible lysosomal thiol reductase is upregulated in human melanoma.

T-cell-mediated immunity has the ability to produce durable antimelanoma responses, resulting in improved survival of patients with advanced melanoma. Antigen presentation is a key determinant of T-cell responses. Gamma-interferon-inducible lysosomal thiol reductase (GILT) is critical for MHC class II-restricted presentation of multiple melanoma antigens to CD4+ T cells. However, GILT expression in melanoma has not been defined. We evaluated GILT and MHC class II expression in human primary and metastatic melanomas and nevi using immunohistochemical analysis. GILT staining in melanocytes was observed in 70% of primary and 58% of metastatic melanomas versus 0% of nevi. When present, the GILT staining intensity in melanocytes was typically faint. Both GILT and MHC class II expression were increased in melanocytes of primary and metastatic melanomas compared with nevi. GILT staining in antigen-presenting cells (APCs) was detected in 100% of primary and metastatic melanomas versus 31% of nevi, and it was typically intense. GILT expression was increased in APCs of primary and metastatic melanomas compared with nevi, whereas MHC class II had equivalent high expression in APCs of all melanocytic lesions. GILT staining in keratinocytes was detected in 67% of primary melanomas versus 14% of nevi and 6% of metastatic melanomas. GILT, but not MHC class II, expression was increased in keratinocytes of primary melanomas compared with nevi and metastases. GILT expression is anticipated to result in improved presentation of melanoma antigens and more effective antimelanoma T-cell responses. GILT expression may be a biomarker of immune recognition of melanoma.

Pan-cytokeratin markers for rapid frozen section immunocytochemistry from head and facial Mohs cases of basal cell carcinoma: a comparison and evaluation to determine the marker of choice

ABSTRACTThe application of immunocytochemistry in the field of Mohs micrographic surgery (MMS) is well established. This study evaluates the use of pan-cytokeratins (AE1/AE3, MNF116 and AE1/AE3+PCK26) in the assessment of basal cell carcinoma (BCC) on frozen tissue debulk specimens. Fifty-five cases of BCC, all from head and facial sites, were assessed in the study. In addition to staining all cases for the three cytokeratin antibodies under investigation, sections were also stained with haematoxylin and eosin (H&E) to demonstrate tumour architecture and morphology. All sections for immunocytochemistry were stained on a Roche Ventana BenchMark Ultra automated platform employing a rapid frozen section protocol. Results were assessed based on the intensity of staining of keratinocytes (scale: 0–100%), as well as sensitivity of staining determined by the total percentage of keratinocytes stained within the tissue section. AE1/AE3 demonstrated the most consistent staining both in terms of intensity of staining and sensitivity, with a mean of 99.1% and 99.9%, respectively. AE1/AE3+PCK26 average results indicated scores of 70.6% for intensity and 87.2% for sensitivity, with MNF116 scoring 92.9% for intensity but only 57.3% for sensitivity. The data indicate that AE1/AE3 is the best pan-cytokeratin antibody to use in the assessment of BCC in MMS. The use of cytokeratin immunocytochemistry is justified in morphologically complex cases of BCC, or in cases where dense inflammatory infiltrate surrounding any suspicious cells make identification of small numbers of tumour cells difficult to determine with just an H&E stain. The significant rationale is that cytokeratin staining is a valuable adjunct in the study of tumour cell assessment in cases of MMS for BCC. In addition, the use of anti-AE1/AE3 cytokeratin antibodies provides the most consistent staining results for such cases.

Hematopoietic Stem Cells: Do They Have a Role in Keloid Pathogenesis?

Keloids are slow growing neoplasms characterized by benign proliferation of fibroblasts that is due, at least in part, to altered cytokine profiles. Stem cells were claimed to play a role in skin tumor development. However, their role in keloid formation is unclear. The current study investigated the immunoreactivity of CD34 and c-KIT antibodies in 30 cases with keloid lesions together with normal skin biopsies of 30, sex and age-matched subjects representing the control group. Examined keloid sections showed positive dermal stromal immunoreactivity for CD34 in 76.7% of cases. CD34 expression intensity and H score were upregulated in keloid tissue relative to normal skin (p < 0.0001, p = 0.0002, respectively) and in perilesional relative to lesional tissue (p = 0.03, p < 0.001, respectively). c-KIT showed positive dermal stromal expression in all cases. Dermal c-KIT expression intensity and H score were upregulated in keloid tissue relative to normal skin (p < 0.008, p < 0.001, respectively) and in perilesional relative to lesional tissue (p < 0.0001, p < 0.001, respectively). Lesional skin showed more staining of basal keratinocytes when compared to perilesional tissue (p < 0.0001). Hematopoietic stem cells may share in keloid pathogenesis. Further studies are warranted to gain firmer conclusion about the exact role played by these cells and the significance of their perilesional accumulation. The future therapy of keloid scars may have to target this stem cell population in order to deprive these tumors of their regenerative cell pools.

Correlation of the expression of human kallikrein‐related peptidases 4 and 7 with the prognosis in oral squamous cell carcinoma

Very few articles have been written about the expression of kallikreins (KLK4 and KLK7) in oral cancers. Therefore, the purpose of this study was to examine and report on their prognostic potential. Eighty archival blocks of primary oral cancers were sectioned and stained for KLK4 and KLK7 by immunohistochemistry. The percentage and the intensity of malignant keratinocyte staining were correlated with patient survival using Cox regression analysis. Both kallikreins were expressed strongly in the majority of tumor cells in 68 of 80 cases: these were mostly moderately or poorly differentiated neoplasms. Staining was particularly intense at the infiltrating front. Patients with intense staining had significantly shorter overall survival (p < .05). This is the first observation on the patient survival influenced by kallikrein expression in oral carcinoma. The findings are consistent with those for carcinomas at other sites, in particular the prostate and ovary. KLK4 and/or KLK7 immunohistochemistry seems to have diagnostic and prognostic potential in this disease.

Role of bcl-2 oncoprotein in oral potentially malignant disorders and squamous cell carcinoma: An immunohistochemical study

The product of bcl-2 gene, bcl-2 protein, an anti-apoptotic protein, is known to be over-expressed in potentially malignant disorders and squamous cell carcinoma (SCC) of the oral cavity. The aim of this study is to compare the topographical aspect and degree of bcl-2 over-expression in potentially malignant disorders including leukoplakia, oral submucous fibrosis (OSMF), and oral lichen planus (OLP), with that of the oral squamous cell carcinoma (OSCC), and to determine whether bcl-2 protein can be considered as a tumor marker. A group of 60 histo-pathologically diagnosed, formalin-fixed, paraffin embedded tissue samples was included in the study. The study group was further subdivided into four groups: Group I, consisting of oral leukoplakia; Group II, OSMF; Group III, OLP and Group IV, OSCC. These samples were collected from Government Dental College, Bangalore, and then subjected to immunohistochemical (IHC) staining using indirect immunoenzyme labeled streptavidin biotin (LSAB) method. Out of 30 cases of OSCC: 11 (36.7%) cases showed greater supra-basal keratinocyte staining; 15 (50%) cases showed greater number of positive cells in the basal cell layer, with relatively less number of supra-basal cells showing positive staining; and, rest of the 4 (13.3%) cases did not show convincing staining. Among the total 30 cases of potentially malignant disorders: 10 each of leukoplakia, OSMF and OLP, 2 (20%), 2 (20%), 4 (40%) of the cases showed greater supra-basal cell layer positive staining and 8 (80%), 6 (60%), 6 (60%) of them showed greater basal cell staining, respectively. Two cases of OSMF did not show convincing staining. In the cases that were bcl-2 positive: 2 (6.67%) of the OSCC, 3 (30%) of leukoplakia, 2 (20%) of OSMF and 1 (10%) of OLP, showed more than 50% of the cells positive. 25-50% cells were positive in 21 (70%) of OSCC, 6 (60%) of leukoplakia, 4 (40%) of OSMF and 6 (60%) of OLP cases. 10-25% of cells were positive in 4 (13.3%) of OSCC, 1(10%) of leukoplakia, 2 (20%) of OSMF and 3 (30%) of OLP cases. Less than 10% of cells were positive in 3 (10%) of OSCC and 2 (20%) of OSMF cases. CLINICAL SIGNIFICANCE AND CONCLUSION: As definite number of cases showed bcl-2 over expression in our study, the role of bcl-2 in the development and progression of oral neoplasia needs further investigation along with other oncogenes.

Soluble Adenylyl Cyclase Defines a Nuclear cAMP Microdomain in Keratinocyte Hyperproliferative Skin Diseases

Cyclic adenosine monophosphate (cAMP) is a nearly ubiquitous signaling molecule important for numerous signaling pathways in human skin. We studied a novel class of mammalian adenylyl cyclase, the soluble adenylyl cyclase (sAC). We examined sAC localization in normal human skin and found it to be present in keratinocytes, melanocytes, mononuclear cells, eccrine ducts, and nerves. In normal skin, sAC keratinocyte staining was evenly distributed throughout the cell. However, in certain hyperproliferative disorders of the skin, including psoriasis, verruca vulgaris, and SCCIS on sun-damaged skin, sAC keratinocyte staining was predominantly nuclear. In contrast, in other hyperproliferative disorders, such as basal cell carcinoma, sAC staining was similar to normal human skin. Using a model of epithelial differentiation, we established that sAC migrates into the nucleus when differentiated cells are induced to reenter the cell cycle. Previous work had determined that nuclear sAC activates the cAMP-response-element-binding (CREB) transcription factor, and we found that in psoriasis lesions, nuclear sAC occurs concomitantly with activation of CREB. Hence, sAC may play a role in the pathogenesis of certain hyperproliferative skin disorders via modulation of gene expression.

Keratinocytes in culture accumulate phagocytosed melanosomes in the perinuclear area

There are many techniques for evaluating melanosome transfer to keratinocytes but the spectrophotometric quantification of melanosomes incorporated by keratinocyte phagocytosis has not been previously reported. Here we describe a new method that allows the spectrophotometric visualization of melanosome uptake by normal human keratinocytes in culture. Fontana-Masson staining of keratinocytes incubated with isolated melanosomes showed the accumulation of incorporated melanosomes in the perinuclear areas of keratinocytes within 48 h. Electron microscopic observations of melanosomes ingested by keratinocytes revealed that many phagosomes containing clusters of melanosomes or their fragments were localized in the perinuclear area. A known inhibitor of keratinocyte phagocytosis which inhibits protease-activated receptor-2, i.e., soybean trypsin inhibitor, decreased melanosome uptake by keratinocytes in a dose-dependent manner. These data suggest that our method is a useful model to quantitate keratinocyte phagocytosis of melanosomes visually in vitro.

Metabolic extract of Fusarium oxysporum induces histopathologic alterations and apoptosis in the skin of Wistar rats

Most patients with Fusarium infection present with affection of the tegumentary system, with the presence of necrotic and/or inflammatory lesions associated with pain. To evaluate the effect of the intradermal application of a metabolic extract of Fusarium oxysporum in the skin of Wistar rats. The extract was obtained from fungal cultivation in Czapek-Dox medium. It was sterilized by filtration through a Millipore membrane, and injected (0.5 mg/mL) intradermally into the skin of rats, which were killed 3, 6, 12, and 24 h after inoculation. Skin specimens were placed in paraffin and stained using hematoxylin and eosin, and toluidine blue, for the evaluation of the inflammatory response, and Sirius red for the quantification of collagen. Terminal deoxynucleotidyl transferase-mediated UTP nick end labelling (TUNEL) was used for the identification of apoptosis. Tissue reactions were graded and compared over time and compartment. The inflammatory reaction reached a peak at 12 h for both the dermis and subcutaneous region, being graded as moderate and moderate to severe, respectively. There was an influx of granulocytes, lymphocytes, and macrophages. A significant increase in the number of mast cells, as well as the presence of hyperemic vessels and apoptotic bodies, was observed. There was TUNEL staining in keratinocytes, fibroblasts, endothelial cells, muscles, and in the cells of the inflammatory infiltrate. There was a significant decrease in the area occupied by collagen after 12 h. The extract induced histopathologic alterations in the skin, probably as a result of the presence of active toxic metabolites.

TLR2 expression in oral cancer, dysplastic and hyperplastic lesions

<h3>Background</h3> Toll-like receptors (TLRs) are transmembrane proteins expressed on chronic inflammatory cells (CIC) and endothelial cells (EC) during inflammation. Initially thought to be primarily involved with immune responses to infection, it is now recognised that malignant keratinocytes may express TLR2, as well as cells in the adjacent connective tissue. <h3>Aims</h3> To investigate TLR2 expression by CIC, EC and keratinocytes in oral squamous cell carcinoma (OSCC), epithelial dysplasia (ED) and irritative hyperplasia (IH) using immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). <h3>Methods</h3> 50 archival OSCC cases, 50 ED and 50 IH were stained via immunohistochemistry (TLR2: Santa Cruz, USA), systematically evaluated and the proportion of positively stained cells to negatively stained cells determined. Keratinocytes were categorised as strongly positive, weakly positive or negative. RT-PCR was carried out on three OSCC samples that strongly expressed TLR2. <h3>Results</h3> TLR2 expression by CIC and EC was significantly higher in OSCC than in IH. All IH samples showed negative staining of keratinocytes while the malignant keratinocytes in approximately 40% of OSCC expressed TLR2. RT-PCR confirmed TLR2 gene expression in cancer cells. <h3>Conclusions</h3> TLR2 expression by malignant keratinocytes may correlate with apoptosis resistance to the benefit of tumour cells, while expression in the tumour microenvironment suggests links between infection and oral carcinogenesis.

Impact of ultraviolet radiation on the expression of marker proteins of gap and adhesion junctions in human epidermis

We aimed to investigate the impact of ultraviolet B (UVB) as well as UVA1 on the epidermal expression of specific markers of gap and adhesion junctions. Twelve healthy subjects were enrolled in the study. The back of the subjects was irradiated with three MED-UVB as well as three MED-UVA1. Twenty-four hours later, punch biopsies were taken from irradiated and non-irradiated skin. Immunohistochemical procedures were used for the detection of connexin 43, E-cadherin, involucrin, Ki-67 using specific antibodies. Staining intensity of connexin 43 in UVB-exposed skin was significantly increased when compared with non-exposed and UVA1-exposed sites. By contrast, staining intensity of E-cadherin in UVB-exposed skin was significantly decreased when compared with non-exposed and UVA1-exposed sites. Involucrin and Ki-67 staining of keratinocytes was significantly increased in UVB-exposed sites as compared with non-exposed and UVA1-irradiated sites. UVB significantly alters the epidermal expression of gap and adhesion junction proteins possibly indicating a role of these proteins in the regulation of UV-induced inflammation and development and progression of skin cancer.

C-terminally truncated kindlin-1 leads to abnormal adhesion and migration of keratinocytes

The Kindler syndrome (KS) protein kindlin-1 is a member of a protein complex that links cortical actin to integrins on the surface of basal keratinocytes. Loss of kindlin-1 leads to abnormalities of cell adhesion and motility, and to skin blistering and progressive poikiloderma as clinical symptoms. Here we investigated a severely affected patient, disclosed the mutation that caused the disease and delineated its biological consequences. Mutation screening of the kindlin-1 gene, KIND1 (now called FERMT1), was performed with polymerase chain reaction (PCR) amplification of all exons and sequencing. Mutated kindlin-1 was characterized by reverse transcriptase (RT)-PCR and immunoblotting, and genotype-phenotype correlations were analysed using immunohistochemical staining of skin biopsies and keratinocytes from the patient's skin. Cell adhesion and motility were assessed with functional tests. We disclosed a splice site mutation in the first position of intron 13 of the FERMT1 gene, which caused skipping of exon 13. The short transcript partially escaped nonsense-mediated mRNA decay and was translated into a truncated protein. A C-terminally truncated kindlin-1 in keratinocytes could not function correctly even if it were expressed.

Adhesion molecule expression in psoriatic skin lesions and the influence of cyclosporin A

Normal skin of healthy individuals and both lesional and uninvolved skin from patients with psoriasis before and after receiving cyclosporin A (CsA; 2.5 or 5 mg/kg per day) was examined by immunocytochemistry for differences in expression of adhesion-relevant epitopes. Normal, lesional and uninvolved skin all showed staining of basal keratinocytes for CD29 (the common beta chain of the beta 1-integrin family). No other adhesion molecule investigated was detected on structural components of normal skin. In uninvolved skin, weak expression of CD54 (intercellular adhesion molecule 1, ICAM-1) was noted on vascular endothelium. Uninvolved keratinocytes were found to stain with anti-CD58 (leucocyte function-associated antigen 3, LFA-3) and there was weak expression of CD11b (alpha chain of complement C3bi receptor) and CD11c (alpha chain of p150, 95 molecule) but not CD11a (leucocyte function-associated antigen 1, LFA-1, alpha chain) on those cells. In lesional skin, in addition to expression of CD58, there was also enhanced expression of CD11c. Weak expression of CD54 on keratinocytes was also observed. Lesional blood vessels were found to stain strongly with anti-CD54, CD29 and CD58. CD11a was expressed only on infiltrating mononuclear cells. CsA treatment produced marked clinical improvement, accompanied by the loss of CD54 expression on keratinocytes. However, despite the loss of T cells from lesional skin with CsA treatment, CD54 persisted on blood vessels. CsA was found to have no effect on keratinocyte expression of CD29, CD58 or CD11b and c. The persistence of CD54 on vascular endothelium and of adhesion molecule expression on keratinocytes, despite resolution of the skin lesions, may explain the universal and rapid recurrence of psoriasis on cessation of CsA administration.