Immunolocalization and characterization of cornification proteins in snake epidermis

Little is known about specific proteins involved in keratinization of the epidermis of snakes, which is composed of alternating beta- and alpha-keratin layers. Using immunological techniques (immunocytochemistry and immunoblotting), the present study reports the presence in snake epidermis of proteins with epitopes that cross-react with certain mammalian cornification proteins (loricrin, filaggrin, sciellin, transglutaminase) and chick beta-keratin. alpha-keratins were found in all epidermal layers except in the hard beta- and alpha-layers. beta-keratins were exclusively present in the oberhautchen and beta-layer. After extraction and electrophoresis, alpha-keratins of 40-67 kDa in molecular weights were found. Loricrin-like proteins recorded molecular weights of 33, 50, and 58 kDa; sciellin, 55 and 62 kDa; filaggrin-like, 52 and 65 kDa; and transglutaminase, 45, 50, and 56 kDa. These results suggest that alpha-layers of snake epidermis utilize proteins with common epitopes to those present during cornification of mammalian epidermis. The beta-keratin antibody on extracts from whole snake epidermis showed a strong cross-reactive band at 13-16 kDa. No cross-reactivity was seen using an antibody against feather beta-keratin, indicating absence of a common epitope between snake and feather keratins.     

Regeneration of the plantar skin in mammals

Two posterior plantar pads together with the surrounding skin were removed from the hind limb in rats, and one plantar pad each without the surrounding skin was removed from the hind and fore limbs of hedgehogs. As a result of healing of the skin wounds in the rats and hedgehogs, areas of regeneration were formed with the typical stratum papillare of plantar skin. In hedgehogs the regenerating skin covered the restored plantar pad. In rats the plantar pads were not restored.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Kraevskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 5, pp. 591–595, May, 1977.     

Psittacine beak and feather disease infected cells show a pattern of apoptosis in psittacine skin.

Skin biopsies from 23 birds with psittacine beak and feather disease (PBFD) were examined by light and electron microscopy. Affected cells, preferentially found in the cell layers of the feather follicles, could be clearly identified by the presence of intracytoplasmic virus inclusion bodies. Ultrastructurally, the degenerative process in these cells was morphologically suggestive of apoptosis.     

Evolution of hard proteins in the sauropsid integument in relation to the cornification of skin derivatives in amniotes

Hard skin appendages in amniotes comprise scales, feathers and hairs. The cell organization of these appendages probably derived from the localization of specialized areas of dermal–epidermal interaction in the integument. The horny scales and the other derivatives were formed from large areas of dermal–epidermal interaction. The evolution of these skin appendages was characterized by the production of specific coiled‐coil keratins and associated proteins in the inter‐filament matrix. Unlike mammalian keratin‐associated proteins, those of sauropsids contain a double beta‐folded sequence of about 20 amino acids, known as the core‐box. The core‐box shows 60%–95% sequence identity with known reptilian and avian proteins. The core‐box determines the polymerization of these proteins into filaments indicated as beta‐keratin filaments. The nucleotide and derived amino acid sequences for these sauropsid keratin‐associated proteins are presented in conjunction with a hypothesis about their evolution in reptiles‐birds compared to mammalian keratin‐associated proteins. It is suggested that genes coding for ancestral glycine‐serine‐rich sequences of alpha‐keratins produced a new class of small matrix proteins. In sauropsids, matrix proteins may have originated after mutation and enrichment in proline, probably in a central region of the ancestral protein. This mutation gave rise to the core‐box, and other regions of the original protein evolved differently in the various reptilians orders. In lepidosaurians, two main groups, the high glycine proline and the high cysteine proline proteins, were formed. In archosaurians and chelonians two main groups later diversified into the high glycine proline tyrosine, non‐feather proteins, and into the glycine‐tyrosine‐poor group of feather proteins, which evolved in birds. The latter proteins were particularly suited for making the elongated barb/barbule cells of feathers. In therapsids‐mammals, mutations of the ancestral proteins formed the high glycine‐tyrosine or the high cysteine proteins but no core‐box was produced in the matrix proteins of the hard corneous material of mammalian derivatives.     

Differences in regeneration of the skin in different species of mammals

The healing of full-thickness skin wounds measuring 1.2 cm² was studied in mink and sable. In both species of animals the skin defect closed mainly through contraction of the wound. Hairs and sebaceous glands were found in the small area of regenerating skin formed in the center of the primary defect. It is postulated that these hairs developed from bulbs of old hairs which migrated into the regenerating zone together with the lower layers of the dermis adjacent to the wound.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 6, pp. 742–745, June, 1976.     

Immunolocalization of aquaporin-9 in rat hepatocytes and Leydig cells

The aquaporin (AQP)-9 gene was recently isolated from human and rat liver cDNA libraries as a member of the water channel family for water and neutral solutes. Although the expression of AQP9 mRNA has been demonstrated in several organs including the liver and testis by Northern blot analysis, the cellular and subcellular localization of the AQP9 protein remains unclear. In the present light and electron microscopic immunohistochemical study, the localization of the AQP9 immunoreactivity was examined in fifteen kinds of rat organs using an antibody against rat AQP9 synthetic peptide. The antibody immunostained a major band of approximately 33 kDa in the liver by Western blot analysis. Immunoreactivity for AQP9 was found exclusively in the liver and testis among the organs examined. In the liver, positive staining appeared selectively along the space of Disse. Immunoelectron microscopy confirmed the localization of AQP9 on the surface of hepatocyte microvilli facing the space of Disse. In the testis, the plasma membrane of Leydig cells located between seminiferous tubules was conspicuously immunoreactive to the antibody. Intense mRNA expression was detected in the liver and testis but not in other organs by ribonuclease protection assay. These findings suggest a specific role for AQP9 in the transport of water and non-charged solutes in hepatocytes and Leydig cells.     

Induction the cornification of squamous cancerous cells to eliminate tumor cells by promotion cell differentiation and stratum

Cornification is a kind of apoptosis of squamous epithelial cell in the upper layer of the epithelial tissue. The basal cells away from cell-cycle embark on terminal differentiation, stratum, then die by apoptosis. The critical elements interference from the normal differentiation of squamous cells will lead to cell malignant transformation. We would like to put forward a hypothesis that initiation the cornification of squamous cancerous cells by promotion cell differentiation and stratum can promote squamous carcinoma cells death. Attempts of induction squamous cancerous cells terminal differentiation will add to our understanding of the connection between keratinocytes cornification and the death of squamous-cell carcinoma.     

Cross reactions in skin tests between house dust mite extract and feather extract

Of 248 patients skin tested with house dust mite extract and feather extract 102 gave reactions with both, thirty-one with mite extract alone and four with feather extract alone. It is believed that nearly all the reactions to feathers were due to mite allergens in the feather extract. As the extract was not made from feathers from old upholstery it is suggested that the reactions might be due to a poultry mite having cross-antigenicity with the house dust mite.     

Immunolocalization of cytokines to mast cells in normal and allergic conjunctiva

Background Recently, the potential role of mast cells in allergic reactions has been extended by the discovery that these cells synthesize, store and secrete multifunctional cytokines. Seasonal allergic conjunctivitis is characterized as an immediate hypersensitivity reaction, in which allergen binds to specitic IgE on mast cells, leading to release of preformed and newly synthesized inflammatory mediators. Objective In this study we aimed to localize the cytokines IL-4, IL-5, IL-6, IL-8 and TNFα to conjunctival mast cells and lo examine the relationship between mast cell-associated ctokines and allergic conjunctivitis. Methods Immunobistochemistry was perfonned on serial sections of conjunctival biopsies from patients with seasonal allergic conjunctivitis, in and out of tbe hay fever season, as well as from non-allergic volunteers. Results IL-4, IL-5, IL-6 and TNFα were localized to mast cells in normal and allergic conjunctiva. IL-8 was localized to mast cells in two patients with seasonal allergic conjunctivitis, one during and the other outside the pollen season. Using the monoclonal antibody 3H4, which identifies the secreted form of IL-4, biopsies frotn patients with active seasonal allergic conjunctivitis contained a significantly bigher proportion of mast cells positive for IL-4. than those from out-of-season patients (P= < 0.016). There was no difference between the two groups in the number of mast cells immunostained by the antibody 4D9 which identifies the stored form of IL-4. Conclusions These results suggest that conjunctival mast cells can store a range of multifunctional cytokines and release IL-4 during active disease, which may give them an important role in upregulating allergic inflamtnation in the conjunctiva.     

哺乳动物外周皮肤温热冷感受器的分子生物学基础

伤害性感受器(nociceptor)是Sherrington(1906)首次提出的概念,指对伤害性或持续性刺激特异敏感的感受器,广泛分布于无毛或有毛皮肤、肌肉、关节和内脏器官的游离神经终末,一般认为属于Aδ和C类神经纤维,前者传导速度为5～30m／s,后者为0．5～2m／s;伤害性刺激(noxious stimulus)是指引起正常组织损伤的刺激。伤害性感觉机制的主     

HIV and metabolic syndrome: a comparison with the general population

OBJECTIVE: To compare the prevalence of metabolic syndrome (MS) in HIV-positive patients with that from a sample of a general Italian population. DESIGN: Cross-sectional study. METHODS: A total of 1263 HIV-infected patients 18 years of age or older were recruited in 18 centers for infectious diseases in northern and central Italy. Controls were 2051 subjects aged 25 to 74 years representative of the residents of Monza, a town in Milan province, who were enrolled in the Pressioni Arteriose Monitorate E Loro Associazioni study. RESULTS: The prevalence of MS in the HIV group was 20.8%, whereas in the control group, it was only 15.8%, with the difference being statistically significant. The age- and gender-adjusted risk of having MS in HIV-infected patients was twice as great as that in controls. Compared with controls, HIV-infected patients had a greater prevalence of the impaired fasting glucose, increased plasma triglycerides, and reduced high-density lipoprotein cholesterol components. MS prevalence was similar in treated and never-treated HIV-infected patients, and so were the various MS components. CONCLUSIONS: The risk of MS is greater in HIV-infected patients compared with the general population because of a greater prevalence of lipid and glucose abnormalities. The prevalence of MS and its components is similar in treated and untreated HIV-positive patients.     

Expression of hard alpha-keratins in pilomatrixoma, craniopharyngioma, and calcifying odontogenic cyst

To examine the properties of shadow and ghost cells, 3 kinds of antibodies were raised against human hair proteins and their immunoreactivity was examined in tumors expressing those cells: pilomatrixoma, 14 cases; craniopharyngioma, 17 cases; and calcifying odontogenic cyst (COC), 14 cases. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analyses demonstrated that 2 polyclonal antibodies, PA-HP1 and PA-HP 2, reacted strongly with type I acidic and type II neutral/basic hard alpha-keratins. The other monoclonal antibody, MA-HP1, reacted with type II neutral/basic hard alpha-keratins. Immunohistochemical examination revealed that all 3 antibodies reacted only with the hair shaft in sections of normal skin and dermoid cyst. In all pilomatrixoma cases, 3 antibodies reacted with the cytoplasm of transitional and shadow cells but not with that of basophilic cells. Positive reactions were found only in shadow cells of all 13 adamantinomatous craniopharyngiomas. In all COCs, the antibodies reacted only with ghost cells, not with other epithelial components. Immunoreactivity for phosphothreonine, detected in hard alpha-keratins, also was found in transitional, shadow, and ghost cells. The appearance of shadow or ghost cells might represent differentiation into hair in these 3 kinds of tumors.