muramidase and Dermatitis

Beside its physical barrier against invading microorganisms, the skin has the ability to produce a number of antimicrobial peptides and proteins, including human beta-defensins, cathelicidin LL-37 and lysozyme that participate in the innate host defense. These antimicrobial agents are strongly active against a wide spectrum of various pathogens such as bacteria, viruses and fungi. Thus, antimicrobial agents are proposed to be promising candidates for innovative anti-infective drugs, and some antimicrobial peptides are currently used in clinical trials for treatment of various skin infections. In addition to their direct antimicrobial functions against invading pathogenic microorganisms, antimicrobial agents have also multiple roles as mediators of inflammation with the effects on epithelial and inflammatory cells, influencing cell proliferation, wound healing, cytokine/chemokine production and chemotaxis. This review describes the biology of these antimicrobial molecules and discusses their structure, expression and functions. Understanding the actions of antimicrobial agents in skin will provide further insight into the mechanism of innate cutaneous disease control, and yield novel therapeutic approaches to the treatment of skin disorders.

Topics: Amino Acid Sequence; Antimicrobial Cationic Peptides; beta-Defensins; Cathelicidins; Dermatitis; Humans; Infections; Molecular Sequence Data; Muramidase

Aryl hydrocarbon receptor nuclear translocator (ARNT) is a transcription factor that binds to partners to mediate responses to environmental signals. To investigate its role in the innate immune system, floxed ARNT mice were bred with lysozyme M-Cre recombinase animals to generate lysozyme M-ARNT (LAR) mice with reduced ARNT expression. Myeloid cells of LAR mice had altered mRNA expression and delayed wound healing. Interestingly, when the animals were rendered diabetic, the difference in wound healing between the LAR mice and their littermate controls was no longer present, suggesting that decreased myeloid cell ARNT function may be an important factor in impaired wound healing in diabetes. Deferoxamine (DFO) improves wound healing by increasing hypoxia-inducible factors, which require ARNT for function. DFO was not effective in wounds of LAR mice, again suggesting that myeloid cells are important for normal wound healing and for the full benefit of DFO. These findings suggest that myeloid ARNT is important for immune function and wound healing. Increasing ARNT and, more specifically, myeloid ARNT may be a therapeutic strategy to improve wound healing.

Topics: Aged; Animals; Aryl Hydrocarbon Receptor Nuclear Translocator; Case-Control Studies; Cells, Cultured; Cytokines; Deferoxamine; Dermatitis; Diabetes Complications; Diabetes Mellitus, Experimental; Female; Gene Expression Regulation; Genotype; Graft Survival; Humans; Immunity, Innate; Immunocompromised Host; Inflammation Mediators; Integrases; Macrophage Activation; Macrophages; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Middle Aged; Monocytes; Muramidase; Myeloid Cells; Phenotype; RNA, Messenger; Skin; Skin Transplantation; Time Factors; Transplantation Tolerance; Wound Healing

A grave prognosis is usually associated with leukemic skin infiltrates (leukemia cutis). However, some leukemic skin infiltrates are clinically similar to reactive non-leukemic infiltrates in patients with leukemia; thus it is of great importance to distinguish them. Fifty-four cases which were thought clinically to be leukemia cutis underwent immunophenotyping with a panel of nine T, B, monocytic, and macrophage markers using paraffin sections. Immunohistochemistry helped identify 44 cases with leukemia cutis and 10 with reactive infiltrates. In all cases of leukemia cutis, the staining patterns of skin infiltrates were concordant with cell type in the bone marrow. Furthermore, the panel of markers was usually helpful in distinguishing reactive from leukemia infiltrates, especially in cases with chronic lymphatic leukemia. Immunohistochemistry is a valuable adjunct in histopathologic differentiation of skin infiltrates in most cases of leukemia. With formalin-fixed, paraffin-embedded biopsies, we recommend that CD45 (LCA), CD45RO (UCHL-1), CD3, CD20 (L-26), CD43 (Leu-22), CD68 (KP-1), lysozyme, and chloroacetate esterase be considered in cases of systemic leukemia with cutaneous papules and nodules that prove difficult to interpret with routine section.

Topics: Acute Disease; Adolescent; Adult; Aged; Antigens, CD; Antigens, CD20; Antigens, Differentiation, B-Lymphocyte; Antigens, Differentiation, Myelomonocytic; Biomarkers, Tumor; Biopsy; Bone Marrow; CD3 Complex; Cell Movement; Dermatitis; Female; Humans; Immunohistochemistry; Leukemia; Leukemia, Lymphocytic, Chronic, B-Cell; Leukemic Infiltration; Leukocyte Common Antigens; Leukosialin; Lymphocytes, Tumor-Infiltrating; Macrophages; Male; Middle Aged; Muramidase; Paraffin; Sialoglycoproteins; Skin; Staining and Labeling

Topics: Blood Protein Electrophoresis; Chemical Phenomena; Chemistry; Dermatitis; Electrophoresis; Eye Manifestations; Female; Humans; Lupus Erythematosus, Systemic; Middle Aged; Muramidase; Tears

Topics: Adrenal Cortex Hormones; Dermatitis; Dermatitis Herpetiformis; Dermatitis, Exfoliative; Dermatologic Agents; Dermatology; Dexamethasone; Humans; Muramidase; Pemphigus; Prednisolone; Prednisone