Spinous Cell Layers Research Articles

Clinicopathological study of 24 cases of monkeypox virus infection-related rashes

Objective: To investigate the clinicopathological characteristics of rashes in monkeypox patients through a series of skin biopsies, and examine their pathological features and the most effective tests. Methods: Patients with monkeypox virus infection admitted to Beijing Ditan Hospital from June to August 2023 were identified. Among them, 24 patients underwent skin biopsies for clinical pathological study that were included in this study. Clinical information, rash pictures, and nucleic acid test results were analyzed using histopathology, immunohistochemistry, RNAscope® hybridization and electron microscopy. Results: All 24 patients were male, including 14 patients with concurrent human immunodeficiency virus infection. Their average age was (32.3±5.4) years. The nucleic acid test confirmed monkeypox virus infection. The clinical feature of monkeypox rashes was solitary rather than clustered distribution, with rashes occurring in similar phase, distinguishing it from herpesvirus. The rashes in these patients were mostly scattered, with an average of (13.0±11.8) rashes, and most commonly present in the perineum, face, limbs, and trunk. The three main pathological features of these rashes were ballooning degeneration of the epidermal spinous cell layer, the characteristic intra-cytoplasmic Guarnieri's bodies and significant infiltration of inflammatory cells in whole dermal layer. Immunohistochemistry, RNAscope® hybridization, and electron microscopy can all effectively detect the monkeypox virus. Electron microscopy showed viral replication in various types of skin cells. Conclusions: The study describes the pathological features of monkeypox virus rashes. Pathological examination of skin biopsy samples is helpful to diagnose these rashes. The study suggests that the monkeypox virus has a unique epitheliotropic affinity and can infect various types of cells in the skin.

Enlarged rete pegs with excessive accumulation of melanosomes leading to darker aging spots revealed by histomorphological measurements of internal structures of the epidermis.

Various histological studies of facial pigmented spot sites such as solar lentigo have been reported, but few studies have used quantitative indices by histomorphometric analysis of the internal structure of pigmented spot sites using non-invasive methods. In the present study, to quantitatively elucidate morphological changes in the epidermis in male, darker-pigmented spots and female, light-pigmented spots, indices that characterize the internal structure of the epidermis in pigmented spot sites were measured using in vivo confocal laser scanning microscopy (CLSM). The darkness of pigmented spots on the cheeks of 69 women and 43 men was analysed using image analysis software. The L* value was calculated from RGB values obtained from facial images. The internal structures of pigmented spots on the cheeks of 13 subjects were observed by CLSM. Various parameters were measured using CLSM images from the surface of the stratum corneum to the bottom of the dermal papillae, including the thickness of the epidermis, melanosome content, and shape of the dermal papillae. Mean ΔL* values between pigmented spots and non-pigmented areas of male subjects were significantly increased in the 40s and 50s compared with those of female subjects. Conspicuous pigmented spots increased in the 40s in male subjects and the 50s in female subjects. In CLSM observations, significant increases in the thickness of the epidermis and melanosome content were confirmed in pigmented spots compared with surrounding non-pigmented areas. In particular, melanosome content in the male subject group with dark-coloured pigmented spots increased significantly to about eight times that of non-pigmented areas, and more than double that of the male subject group with light-coloured pigmented spots. From the measurements of quantitative parameters, morphological changes in the epidermis were clearly related to the surface colour tone of pigmented spots. Darker pigmented spot sites tended to show longer rete pegs in the epidermis. Accumulation of melanosomes in epidermal basal cells could be considered to increase with the degree of elongation of rete pegs at pigmented spot sites and, thus, induce darker pigmented spots.

Variants in the Gene Encoding Filaggrin Cause Autosomal-Dominant Symmetrical Acral Keratoderma

Variants in the Gene Encoding Filaggrin Cause Autosomal-Dominant Symmetrical Acral Keratoderma

Effect of acupuncture and moxibustion on skin barrier function in guinea pigs with eczema of skin damp-heat accumulation

To observe the effect of acupuncture and moxibustion on the water content of stratum corneum (WCSC), expression of serum inflammatory factors and aquaporin 3 (AQP3) in skin, lung and rectum in guinea pigs with eczema of skin damp-heat accumulation, and to explore the possible mechanism of acupuncture and moxibustion for regulating skin barrier function. A total of 24 male albino guinea pigs were randomly divided into a blank group (n=6) and a modeling group (n=18). The guinea pigs in the modeling group were induced by 2,4-dinitrochlorobenzene (DNCB) to establish the eczema model of skin damp-heat accumulation. The guinea pigs with successful modeling were further randomly divided into a model group, a medication group and an acupuncture-moxibustion group, 6 guinea pigs in each group. The guinea pigs in the medication group were treated with loratadine tablets (0.8 mg/kg) by gavage, once a day for 7 days; the guinea pigs in the acupuncture-moxibustion group were treated with acupuncture at "Feishu" (BL 13), "Pishu" (BL 20), "Quchi" (LI 11), "Zusanli" (ST 36) and "Xuehai" (SP 10); at the same time, moxibustion was applied at "Feishu" (BL 13) and "Zusanli" (ST 36), moxibustion intervention for 10 min and needle retaining for 15 min at each acupoint, once a day for 7 days. The eczema area and severity index (EASI) score was evaluated before and After intervention, and WCSC and trans-epidermal water loss (TEWL) were measured by skin tester. After intervention, The HE staining was used to observe the changes of skin histomorphology in each group; ELISA was used to measure the contents of serum immunoglobulin E (IgE), interleukin (IL)-4 and IL-17; Western blot was used to measure the protein expression of AQP3 in skin, lung and rectum. Before the intervention, compared with the blank group, the EASI scores and TEWL were increased in the remaining groups (P<0.01), and the WCSC was decreased (P<0.01). After the intervention, compared with the model group, the EASI scores and TEWL were decreased (P<0.05, P<0.01), and WCSC was increased (P<0.01) in the medication group and the acupuncture-moxibustion group. The epidermal structure in the blank group was complete and the fibers in the dermis were arranged orderly; in the model group, epidermal hyperkeratosis, proliferation of granular layer, spinous cell layer and basal layer, and disordered arrangement of dermal fibers and infiltration of inflammatory cells were observed. The morphological performance in the medication group and the acupuncture-moxibustion group was better than that in the model group. Compared with the blank group, the contents of serum IgE and IL-17 were increased (P<0.01), and the content of serum IL-4 and the protein expression of AQP3 in skin, lung and rectum were decreased in the model group (P<0.01, P<0.05). Compared with the model group, the contents of serum IgE and IL-17 were decreased and the contents of serum IL-4 were increased in the medication group and the acupuncture-moxibustion group (P<0.01), and the protein expression of AQP3 in skin, lung and rectum in the acupuncture- moxibustion group were increased (P<0.05). Compared with the medication group, the contents of serum IgE and IL-17 were increased (P<0.01), and the content of serum IL-4 was decreased (P<0.01) in the acupuncture-moxibustion group. Acupuncture and moxibustion could improve the epidermal water metabolism and skin tissue morphology in guinea pigs with eczema of skin damp-heat accumulation. Its mechanism may be related to regulating inflammatory factors, up-regulating the expression of AQP3, and then repairing the skin barrier function.

Oral verruciform hyperkeratotic lesions indicating the presence of plantar or palmoplantar keratodermas

Oral verruciform hyperkeratotic lesions (OVHLs) affecting the gingiva and palate are frequent in proliferative verrucous leukoplakia (PVL). Intraoral hyperkeratotic lesions can also be observed in epidermolytic keratodermas, albeit such association has received limited attention in oral and maxillofacial pathology. The authors report on 5 individuals whose plantar (PK) or palmoplantar keratodermas (PPKs) were confirmed after evaluation of gingival leukoplakic biopsies. Two women and 3 men, ages 18 to 64, presented with solitary or diffuse leukoplakias of the attached gingiva and hard palate, clinically interpreted as PVL. All individuals underwent diagnostic gingival and/or palatal biopsies. Microscopically, the lesions featured verruciform hyperparakeratosis, occasionally conspicuous hypergranulosis and acanthosis. In the spinous cell layer, numerous cells presented with vacuolated cytoplasm and paranuclear eosinophilic condensations that, infrequently, engulfed the nucleus. The histopathologic findings were interpreted as verrucous hyperkeratosis consistent with those described in epidermolytic PPKs. Further evaluation of the individuals for cutaneous lesions disclosed PK or PPKs in all 5 patients. Additionally, the men exhibited elbow and subungual hyperkeratoses. A family history of keratodermas was confirmed in all 3 male individuals. Gingival and/or palatal OVHLs associated with PK and PPKs display pathognomonic histopathologic features and exhibit indolent biologic behavior. Therefore, any confusion with PVL should be avoided to prevent overtreatment.

Oral Melanoacanthoma: A series of 33 cases and Review of the Literature

<h3>Background</h3> Oral Melanoacanthoma (OM) is an unusual, likely reactive heavily pigmented, benign epithelial proliferation. OM often grows rapidly mimicking melanoma and leading to anxiety for both the patient and the clinician. We present a large series of OM including demographics, description of clinical appearance and characteristics, histology, and literature review. To the best of our knowledge, this is the largest series of OM reported to date. <h3>Materials and Methods</h3> Following IRB approval, OM cases from the University of Florida Oral Pathology Biopsy Service archives (1998-2020) were included. Demographics and clinical features were collected and slides were reviewed. <h3>Results</h3> 33 cases were included with a mean age of 38 years, female: male ratio of 2.6:1. The most common location was buccal mucosa (n = 16, 48.48%), followed by palate (n = 11, 33.33%), tongue and labial mucosa (n = 2 each, 6.06%), maxillary and mandibular gingiva (n = 1 each, 3.03%). Most lesions are dark black/brown, and often described as macular in nature. Duration ranged from one week to twelve months, and all cases were asymptomatic. The clinical impression in the majority of cases were that of a benign melanotic lesion. Ethnicity was only documented in 6/33 cases, of which five cases were African American and one was Caucasian. Histomorphologically, majority of cases (n=27, 81.8%) were hyperplastic/acanthotic, while atrophic epithelium cases were (n=4, 12.1%) and less commonly, spongiotic epithelium cases were (n=2, 6.06%). <h3>Conclusion</h3> The findings of this study are consistent with those in the literature concerning demographics and clinical presentation. Histologically, presence of dendritic melanocytes extending into the spinous cell layer along with acanthosis of the spinous cell layer is diagnostic for OM when combined with the clinical presentation. However, it is important to add cases of OM to the literature so clinicians can be more aware of this lesion.

Epidermal structure and differentiation.

In this Primer, Moreci and Lechler follow the lifetime of an epidermal cell from its birth to its ultimate death, and detail how this journey is necessary for epidermal function.

HAIRY LEUKOPLAKIA IN A PATIENT UNDERGOING ANTI-RETROVIRAL THERAPY

We report a case of hairy leukoplakia that developed in a patient undergoing anti-retroviral therapy. A 53-year old white male presented with mild erythema in the anterior maxillary gingiva and was managed with clobetasol gel, after excluding the possibility of candidiasis. Patient's medical history was significant for HIV, bipolar disorder, high blood pressure, high cholesterol, chronic bronchitis, smoking, and alcohol. His medications included Androgel, Axiron, atorvastatin, bupropion, clonazepam, finasteride, hydrochlorothiazide, lamotrigine, lisinopril, pantoprazole, Prezcobix, Trazadone, Truvada (200 mg emticitabine, 300 mg tenofovir), Ziprasidone, zolpidem, and baby aspirin. During one of multiple follow-up appointments, an asymptomatic white plaque was identified on right lateral tongue. Clinical differential diagnoses included hairy leukoplakia and hyperkeratosis secondary to trauma. Patient reported that his physician changed Truvada to Descovy (200 mg emticitabine, 25 mg tenofovir) since his last appointment. At the appointment six weeks later, the white plaque increased in size, and additional white plaques were found on the left dorso-lateral surface and dorsal tongue. Two biopsies were taken, one from the right lateral and the other from left dorso-lateral tongue. The biopsies showed similar histological features including hyperparakeratosis with shaggy surface and bacterial colonization. Intracellular edema and pyknotic nuclei were noted in the spinous cell layer. Upper spinous cell nuclei were enlarged and glassy appearing, without obvious nucleoli or nuclear beading. An Epstein-Barr encoding region (EBER) in-situ hybridization was performed, which demonstrated presence of EBV. Blood testing, taken five days after the biopsy, showed a CD4 count and viral load within normal limits. The patient's physician prescribed a course of acyclovir 800mg for treating oral hairy leukoplakia. The oral lesions reduced in size at the follow-up appointment three weeks after completion of acyclovir therapy. Further follow-up information also will be presented.

Orthokeratinized Odontogenic Cyst with an Associated Keratocystic Odontogenic Tumor Component and Ghost Cell Keratinization and Calcifications in a Patient with Gardner Syndrome

Gardner syndrome (GS) is caused by mutations in the APC and besides adenomatous colorectal polyps includes such manifestations as osteomas, epidermoid cysts (ECs) and occasionally multiple pilomatricomas. More than 50% of ECs in patients with GS exhibit pilomatricoma-like ghost cell keratinization. The latter may be explained by the fact that the development of both GS and pilomatricoma is driven by activation of the Wnt/β-catenin signaling pathway. A 62-year-old, Caucasian male with history of GS presented with a unilocular, mixed radiopaque/radiolucent mandibular lesion causing divergence and external root resorption of involved teeth. Histopathologically, the lesion was composed of two cystic components, an orthokeratinized odontogenic cyst (OOC) and a smaller one with characteristics of keratocystic odontogenic tumor (KCOT) featuring, focally, ghost cells and an epithelial morule-like structure. Dystrophic calcifications essentially similar to those seen in pilomatricomas were observed in the fibrous connective tissue wall. The KCOT and OOC epithelia revealed strong and diffuse cytokeratin (AE1/AE3) and β-catenin immunoreactivity. CD10 positive immunostaining was seen in the keratin and superficial spinous cell layers in both OOC and KCOT. The intraepithelial and mural ghost cells showed a cytokeratin (+), β-catenin and CD10 (-) immunophenotype. The diagnosis of OOC with ghost cell calcifications in association with KCOT was rendered. The patient was lost to follow-up. Although a coincidental co-existence cannot be excluded, ghost cell calcifications mimicking pilomatricoma-like changes in an unusual odontogenic cyst combining OOC and KCOT features as seen in this patient with GS may be explained by the common molecular mechanisms underlying the pathogenesis of cutaneous pilomatricomas and GS.

Morphometry As a Diagnostic Tool for Potentially Malignant Lesions.

Though we are in 21(st) century with nano technology & tissue printing, there still exist many lacunae in the field of diagnosis. Not much is known about prognostic markers till now from literature to assess potentially malignant lesions. Lesions so called potentially malignant can be termed only after clinical & malignant changes have been developed and there are no means of predicting with certainty the risk of cancerous transformation. Our present study was undertaken to establish the morphometric parameters of the parabasal and spinous cells of normal oral epithelium with the changes occurring in cells of Oral Leukoplakia (OL), Oral Verrucous Carcinoma (OVC) and Oral Squamous Cell Carcinoma (OSCC). Total 40 patients were divided into Group I which includes patients with normal oral mucosa, group II oral leukoplakia patients, group III oral verrucous carcinoma patients and group IV includes oral squamous cell carcinoma patients. Tissue sections were taken and morphometric analysis of cell area, cell diameter, nuclear area, nuclear diameter, nuclear cytoplasmic ratio was done for parabasal and spinous layer cells. Statistical analysis was done using one-way ANOVA and T-test. Nuclear diameter, nuclear area, cell area, nuclear cytoplasmic ratio were significantly increased in OL, OVC, OSCC patients than normal oral mucosa, which was statistically significant. Cell diameter was decreased in OL, OVC, OSCC patients than with normal oral mucosa which was statistically significant. Cellular & nuclear parameters showed statistically significant changes in oral leukoplakia, oral verrucous carcinoma & oral squamous cell carcinoma in comparison with normal oral mucosa.

A Molluscum contagiosum fusion protein inhibits CCL1-induced chemotaxis of cells expressing CCR8 and penetrates human neonatal foreskins: clinical applications proposed.

Inflammation in atopic dermatitis is mediated in part by the chemokine CCL1 and its receptor, CCR8. Recombinant Molluscum contagiosum viral protein (rMC148p), a cc-chemokine homolog, inhibits CCL1-induced chemotaxis of cells expressing CCR8. rMC148p was prepared using the baculovirus/Sf9 insect cell expression system. The recombinant MC148 fusion protein (rMC148fp), rMC148-TAT-6xHis, was similarly prepared by adding base sequences onto the PCR primers to fuse TAT and 6xHis to rMC148p at the carboxyl terminus. rMC148fp retains the capacity of rMC148p to inhibit CCL1-induced chemotaxis. Furthermore, unlike rMC148p, topically applied rMC148fp penetrates stratum corneum of human neonatal foreskins and concentrates along the basal and lower spinous cell layers of the epidermis. rMC148fp may be a safe and effective agent in the treatment of atopic dermatitis and other CCR8-mediated disorders.

α-Synuclein inclusions in the skin of Parkinson's disease and parkinsonism.

ObjectiveThe presence in the brain of α-synuclein containing Lewy neurites, or bodies, is the histological hallmark of Parkinson's disease (PD). The discovery of α-synuclein aggregates in nerve endings of the heart, digestive tract, and skin has lent support to the concept of PD as a systemic disease. Our goals were, first, to demonstrate the presence of α-synuclein inclusions in the skin and, second, to detect quantitative differences between patients with PD and atypical parkinsonism (AP).MethodsSkin biopsies were taken from 67 patients and 20 controls. The biopsies underwent immunohistochemistry (IHC) and immunofluorescence (IF) testing for α-synuclein, whereupon its presence was quantified as the percentage of positive cells. Patients were divided into those with PD and those with AP. AP patients included AP with neurodegenerative disease (proteinopathies) and secondary AP.ResultsSixty-seven patients (34 with PD) and 20 controls were recruited. In the PD group, α-synuclein was detected in 58% of the cells in the spinous cell layer (SCL), 62% in the pilosebaceous unit (PSU), and 58% in the eccrine glands (EG). The AP-proteinopathies group showed 7%, 7%, and 0% expression of α-synuclein, respectively. No expression was found in the skin of the control group.ConclusionsThe expression of α-synuclein in the skin was relatively high in the PD group, scarce in AP, and null for the individuals in the control group. While these findings require further confirmation, this minimally invasive technique may aid in the improvement of the accuracy of PD diagnoses.

Notch signaling may be involved in the abnormal differentiation of epidermal keratinocytes in psoriasis.

Localization of each keratin isoform differs among epidermal layers. Proliferating basal cells synthesize keratin 14 (K14) and suprabasal cells express keratin 10 (K10) in normal skin. Notch signaling is essential for keratinocyte differentiation. Notch1 is expressed in all epidermal layers, Notch2 in the basal cell layer and Notch3 in basal cell and spinous cell layers in normal epidermis. It has been poorly elucidated how localization and expression levels of Notch molecules are related to epidermal molecular markers K10 and K14 in psoriatic skin with abnormal differentiation of epidermal tissue. This study aimed to investigate the relationship between abnormal differentiation of epidermal cells in psoriatic skin and expression of Notch molecules. We investigated keratins (K14 and K10) and Notches (1, 2, 3 and 4) using immunohistochemistry in psoriatic skin (n=30) and normal skin (n=10). In normal skin, K14 and K10 were discretely observed in the basal cell layer and suprabasal layer, respectively. In psoriatic skin, K14 was expressed in the pan epidermal layer while it and K10 were co-expressed in some middle suprabasal layer cells. Notch1, 2, 3, and 4 localized in all epidermal layers in normal skin. In psoriatic skin, Notch1, 2, and 4 mainly localized in suprabasilar layers and Notch3 is lacalized in pan epidermal, suprabasilar, and basilar layers. Protein and mRNA of Notch1, 2, and 3 isoforms decreased in psoriatic epidermis compared with normal epidermis. These data suggest that decrements in these Notch molecules might cause aberrant expression of K10 and K14 leading to anomalous differentiation of the epidermis in psoriatic lesions.

Learning from eponyms: George F. Odland and Odland bodies.

Odland bodies (lamellar) bodies are small sub-cellular structures of size 200-300 nm that are present in the upper spinous and granular cell layers of the epidermis. These act as processing and repository areas for lipids that contribute to the epidermal permeability barrier. They also contain proteases, cathepsin D, kallikrein and other proteins including corneo-desmosins. Recent information also credits them with a role in the local innate immune response as they contain beta 2 defensins, which are anti-microbial peptides with potent activity against Gram-negative bacteria and candida. Odland bodies are important for maintaining homeostasis of the epidermis and are involved in epidermal permeability barrier function, desquamation of keratinocytes, formation of the cornified envelope and in local anti-microbial immunity. This article reviews the structure and functions of these bodies with a brief biography of George F. Odland who first described these bodies in 1960 and whose name is eponymically associated with them.

Transforming growth factor beta 1 in oral submucous fibrosis: An immunohistochemical study - Understanding the pathogenesis

Background: The development of fibrosis is pathognomic in the potentially malignant oral disorder, oral submucous fibrosis (OSF). Strong evidence exists to implicate the chewing of areca nut in the pathogenesis of the lesion. The constituents of areca nut activate several pro-fibrotic cytokines, chiefly transforming growth factor beta 1 (TGF-β1), which leads to an increased deposition and decreased degradation of extracellular matrix and collagen. TGF-β1 probably represents the major pathway in the deposition of collagen fibers in this condition. The present study aims to identify and correlate the expressions of TGF-β1 immunohistochemically on paraffin sections of various stages of OSF. Materials and Methods: The expression of TGF-β1 antibody was detected immunohistochemically using the anti-TGF-β1 mouse monoclonal antibodies (8A11-NovusBio USA) on paraffin sections of 58 cases of OSF, 10 cases of normal buccal mucosa tissue and 5 cases of scar tissue. The site, extent, and intensity of expression and quantification of TGF-β1 were noted and a comparative evaluation between various grades of OSF. Scar tissue and normal oral mucosa was made using image analysis software (Jenoptik optical system-ProReg ® Capture Pro 2.8.8 software [2011]). Results: Cells of spinous layer of the epithelium showed more intense staining in all grades of OSF, Grade II showed the highest percentage of expression, same as that of keloid (17%) but less than that of normal mucosa (12%). Positive staining was seen around blood vessels, muscles, fibers in the submucosa and perimuscle fibers. Highest expression was in the muscle in Grade III (80%) compared with normal oral mucosa (37%). Conclusion: These results suggest that the pathogenesis of OSF and scar/keloid could be linked through the TGF-β1 pathway. Interventions directed at the TGF-beta pathway may hold the key in the future management of this oral potentially malignant condition.

Czynnik wzrostu komórek rogowaciejących i jego receptor w perlaku ucha środkowego

AimEtiology of middle ear cholesteatoma is far from beeing elicidated. Current concepts postulate that cholesteatoma is the result of disturbed wound healing process. Keratinocyte growth factor (KGF) plays important role in wound healing, so it seemed interesting to assess the expression of KGF and its receptor in the cholesteatoma. Material and methods25 cholesteatoma and 7 retraction pockets specimens were obtained from the patients during middle ear surgery. The expression of KGF and FGFR2 was evaluated by immunohistochemical staining using polyclonal antibodies. The results were analyzed depending on clinical features such as: localization, number of anatomic sites involved and presence of purulent discharge. ResultsKGF expression was detected in the cells of subepithelial tissue. It was observed in 4/7 (57%) of the specimens of retraction pockets and 11/25 (44%) of cholesteatoma specimens. FGFR2 expression was observed mainly in the cells of spinous layer of epithelium in 4/7 (57%) specimens of retraction pockets and 19/25 (76%) of specimens of cholesteatoma. Statistically significant (p=0.011) relationship between the presence of KGF expression in the subepithelial tissue and the presence of FGFR2 expression in the epithelium was found. There were no differences in the expression of KGF and FGFR2 between retraction pocket and cholesteatoma specimens. Also, no differences in the expression, depending on localization, extend of the cholesteatoma and presence of purulent discharge were observed. ConclusionKGF and its receptor seem to play an important role in paracrine regulation of cholesteatoma growth.

Calcium–calmodulin signaling induced by epithelial cell differentiation upregulates BRAK/CXCL14 expression via the binding of SP1 to the BRAK promoter region

The chemokine BRAK/CXCL14 (BRAK) is expressed in normal squamous epithelium, but is not expressed or is expressed at negligible levels in head and neck squamous cell carcinoma. Malignant cells are known to be dedifferentiated compared with normal epithelial cells, suggesting a role for differentiation cues in the expression of BRAK. Thus, we examined the relationship between BRAK expression and stages of differentiation level in epithelial cells. Immunohistochemical analysis showed that BRAK protein was expressed in cells above the spinous cell layer in normal epithelia. In HSC-3 cells in culture, expression of BRAK mRNA was significantly upregulated by cell contact in a cell density-dependent manner, and mRNA expression of cell differentiation markers such as involucrin, cystatin-A, TGM1, TGM3, and TGM5 was concomitantly augmented. Furthermore, the upregulation of BRAK induced by cell contact was suppressed by chlorpromazine, a specific inhibitor of calmodulin. We previously reported that GC boxes and a TATA-like sequence in the BRAK promoter region are associated with the expression of BRAK. Using a promoter assay and ChIP, we demonstrated that binding of the stimulating protein-1 (SP1) transcription factor to a GC box upstream of the BRAK transcription start site was necessary for cell density-dependent upregulation of BRAK. These results indicated that upregulation of BRAK was accompanied by differentiation of epithelial cells induced by calcium/calmodulin signaling, and that SP1 binding to the BRAK promoter region played an important role in this signaling.

Cells of the skin immune system in dogs with atopy

Twenty-five dogs with signs of atopic dermatitis were included in this study. Additionally, 10 healthy dogs were chosen as healthy skin controls. Skin biopsy specimens were taken from these dogs and evaluated for the following cells: basal cell layer including the number of mitotic figures in this layer, spinous cell layer, macrophages, melanocytes, mast cells and dendritic cells. Identification of mast cells and dendritic cells was performed by means of immunohistochemistry. Histological and statistical investigations showed that the number of mitotic figures in the basal cell layer as well as the number of mast cells, melanocytes, dendritic cells and macrophages was significantly higher in the skin of dogs with atopic dermatitis compared to the healthy dogs (p&lt; 0.01). This finding indicates multilateral quantitative activation within the cellular elements of the skin immune system. Furthermore, marked morphological heterogeneity and distinct degranulation patterns observed among mast cells in atopic skin points to their significant functional activation and confirms that canine atopic dermatitis is still notably a mast cell-dependent disease.

Compound Heterozygous Desmoplakin Mutations Result in a Phenotype with a Combination of Myocardial, Skin, Hair, and Enamel Abnormalities

Desmoplakin (DP) anchors the intermediate filament cytoskeleton to the desmosomal cadherins and thereby confers structural stability to tissues. In this study, we present a patient with extensive mucocutaneous blisters, epidermolytic palmoplantar keratoderma, nail dystrophy, enamel dysplasia, and sparse woolly hair. The patient died at the age of 14 years from undiagnosed cardiomyopathy. The skin showed hyperplasia and acantholysis in the mid- and lower epidermal layers, whereas the heart showed extensive fibrosis and fibrofatty replacement in both ventricles. Immunofluorescence microscopy showed a reduction in the C-terminal domain of DP in the skin and oral mucosa. Sequencing of the DP gene showed undescribed mutations in the maternal and paternal alleles. Both mutations affected exon 24 encoding the C-terminal domain. The paternal mutation, c.6310delA, leads to a premature stop codon. The maternal mutation, c.7964 C to A, results in a substitution of an aspartic acid for a conserved alanine residue at amino acid 2655 (A2655D). Structural modeling indicated that this mutation changes the electrostatic potential of the mutated region of DP, possibly altering functions that depend on intermolecular interactions. To conclude, we describe a combination of DP mutation phenotypes affecting the skin, heart, hair, and teeth. This patient case emphasizes the importance of heart examination of patients with desmosomal genodermatoses.

Expression pattern of GATA‐3 in embryonic and fetal human skin suggests a role in epidermal and follicular morphogenesis

The transcription factor GATA-3 was recently identified as a master regulator in the specification of the inner root sheath. Additionally, it seems to play a role in skin barrier physiology. p63 binds and transactivates the GATA-3 promoter. While the expression profile of GATA-3 is delineated for the mouse, little is known about its expression in the adult human hair follicle and no studies are published about its distribution during human cutaneous embryogenesis. We examined samples from embryonic, fetal and adult human skin for the expression of GATA-3 using immunohistochemistry. GATA-3 is expressed late during human skin development. Its expression pattern is comparable to the mouse and confined to the Huxley layer and inner root sheath cuticle but sparing the Henle layer. In addition, GATA-3 localizes to the spinous cell layer of the interfollicular epidermis. From the described expression pattern, it is highly probable that GATA-3 plays a role in follicular and epidermal morphogenesis. What the anatomically confined expression of GATA-3 to the spinous layer means biologically for the physiology of the skin is still unclear. Likewise, it still needs to be shown if GATA-3 could be exploited in the diagnosis of adnexal neoplasms.