Evolutionary conservation and changes in insect TRP channels.

BACKGROUND: TRP (Transient Receptor Potential) channels respond to diverse stimuli and thus function as the primary integrators of varied sensory information. They are also activated by various compounds and secondary messengers to mediate cell-cell interactions as well as to detect changes in the local environment. Their physiological roles have been primarily characterized only in mice and fruit flies, and evolutionary studies are limited. To understand the evolution of insect TRP channels and the mechanisms of integrating sensory inputs in insects, we have identified and compared TRP channel genes in Drosophila melanogaster, Bombyx mori, Tribolium castaneum, Apis mellifera, Nasonia vitripennis, and Pediculus humanus genomes as part of genome sequencing efforts. RESULTS: All the insects examined have 2 TRPV, 1 TRPN, 1 TRPM, 3 TRPC, and 1 TRPML subfamily members, demonstrating that these channels have the ancient origins in insects. The common pattern also suggests that the mechanisms for detecting mechanical and visual stimuli and maintaining lysosomal functions may be evolutionarily well conserved in insects. However, a TRPP channel, the most ancient TRP channel, is missing in B. mori, A. mellifera, and N. vitripennis. Although P. humanus and D. melanogaster contain 4 TRPA subfamily members, the other insects have 5 TRPA subfamily members. T. castaneum, A. mellifera, and N. vitripennis contain TRPA5 channels, which have been specifically retained or gained in Coleoptera and Hymenoptera. Furthermore, TRPA1, which functions for thermotaxis in Drosophila, is missing in A. mellifera and N. vitripennis; however, they have other Hymenoptera-specific TRPA channels (AmHsTRPA and NvHsTRPA). NvHsTRPA expressed in HEK293 cells is activated by temperature increase, demonstrating that HsTRPAs function as novel thermal sensors in Hymenoptera. CONCLUSION: The total number of insect TRP family members is 13-14, approximately half that of mammalian TRP family members. As shown for mammalian TRP channels, this may suggest that single TRP channels are responsible for integrating diverse sensory inputs to maintain the insect sensory systems. The above results demonstrate that there are both evolutionary conservation and changes in insect TRP channels. In particular, the evolutionary processes have been accelerated in the TRPA subfamily, indicating divergence in the mechanisms that insects use to detect environmental temperatures.

Karyotypic analysis of bone marrow cells in pyodermic lesions associated with myelodysplastic syndrome.

BACKGROUND: Recalcitrant pyodermic lesions and neutrophilic dermatoses are often associated with subclinical myelodysplastic syndrome (MDS). In this case series, we assessed the diagnostic importance of karyotypic analysis of bone marrow cells in 4 patients with MDS-associated pyodermic eruptions treated at our university hospital. Karyotypic analysis was performed in bone marrow cells and peripheral blood lymphocytes obtained. Serum levels of granulocyte colony-stimulating factor were measured. OBSERVATIONS: Four patients with pyodermic eruptions or neutrophilic dermatosis had chromosomal abnormalities in bone marrow cells, including del(20)(q11;q13.3) in 2 patients, trisomy 8 in 1 patient, and t(11;22)(q23;q11) in 1 patient. Three patients without morphologic findings suggestive of MDS were diagnosed as having refractory anemia. One female patient had refractory anemia with ringed sideroblasts associated with del(20). Two patients with refractory anemia had a normal karyotype in peripheral blood lymphocytes. Two patients with elevated serum levels of granulocyte colony-stimulating factor had more active or widespread cutaneous diseases. CONCLUSIONS: Karyotypic analysis of bone marrow cells, but not of peripheral blood lymphocytes, is essential in proving a diagnosis of MDS-associated pyodermic lesions. The overexpression of granulocyte colony-stimulating factor, which may compensate for impaired hematopoiesis in patients with MDS, seems to be a key cytokine leading to neutrophilic infiltration.

Oculocutaneous albinism type 4: six novel mutations in the membrane-associated transporter protein gene and their phenotypes.

Oculocutaneous albinism type 4 (OCA4) is an autosomal recessive hypopigmentary disorder caused by mutations in the Membrane-Associated Transporter Protein gene (SLC45A2). The SLC45A2 protein is a 530-amino-acid polypeptide that contains 12 putative transmembrane domains, and appears to be a transporter that mediates melanin synthesis. Eighteen pathological mutations have been reported so far. In this study, six novel mutations, p.Y49C (c.146A > G), p.G89R (c.265G > A), p.C229Y (c.686G > A), p.T437A (c.1309A > G), p.T440A (c.1318A > G) and p.G473D (c.1418G > A) were found in eight Japanese patients with various clinical phenotypes. The phenotypes of OCA4 were as various as the other types of OCA and probably depended on the mutation sites in the SLC45A2 gene.

Heparanase regulates esophageal keratinocyte differentiation through nuclear translocation and heparan sulfate cleavage.

Heparanase is an endo-beta-glucuronidase that specifically cleaves heparan sulfate (HS) chains. Heparanase is involved in the process of metastasis and angiogenesis through the degradation of HS chains of the extracellular matrix and cell surface. Recently, we demonstrated that heparanase was localized in the cell nucleus of normal esophageal epithelium and esophageal cancer, and that its expression was correlated with cell differentiation. However, the nuclear function of heparanase remains unknown. To elucidate the role of heparanase in esophageal epithelial differentiation, primary human esophageal cells were grown in monolayer as well as organotypic cultures, and cell differentiation was induced. Expression of heparanase, HS, involucrin, and p27 was determined by immunostaining and Western blotting. SF4, a novel pharmacological inhibitor, was used to specifically inhibit heparanase activity. Upon esophageal cell differentiation, heparanase was translocated from the cytoplasm to the nucleus. Such translocation of heparanase appeared to be associated with the degradation of HS chains in the nucleus and changes in the expression of keratinocyte differentiation markers such as p27 and involucrin, whose induction was inhibited by SF4. Furthermore, these in vitro observations agreed with the expression pattern of heparanase, HS, involucrin, cytokeratin 13, and p27 in normal esophageal epithelium. Nuclear translocation of heparanase and its catalytic cleavage of HS may play a critical role in the differentiation of esophageal epithelial cells. Our study provides a novel insight into the role of heparanase in an essential differentiation process.

Generalized morphea-like lesions arising in mechanically-compressed areas by underclothes.

We report two patients with generalized morphea-like eruptions, the distribution of which was confined to areas mechanically compressed by underclothes. One patient had Raynaud's phenomenon and anti-centromere antibodies, and the other patient had a long history of occupational exposure to organic solvents. We believe that the Koebner phenomenon, resulting from local compression by underclothes, might be responsible for the development of morphea-like lesions in patients with subclinical systemic sclerosis.

Interferon-gamma-induced 15-lipoxygenase-2 expression in normal human epidermal keratinocytes and a pathogenic link to psoriasis vulgaris.

Epidermal keratinocytes contain 15-lipoxygenase, which generates 15-hydroxyeicosatetraenoic acid, a major metabolite of arachidonic acid. Although two isozymes, 15-lipoxygenase-1 and -2, exist, it remains unclear which isozyme plays an important role in inflammatory processes and proliferative skin diseases. In the present study, we demonstrated that 15-lipoxygenase-2 expression was increased in normal human epidermal keratinocytes and HaCaT cells treated with interferon-gamma (200 U/ml), while no induction of 15-lipoxygenase-1 was observed. Under the same culture conditions, no 15-lipoxygenase-2 was expressed by a carcinoma cell line, A431. Weak expression of 15-lipoxygenase-2 was observed in the basal cell layer of non-lesional psoriatic skin by in situ hybridization and immunostaining, whereas strong expression of 15-lipoxygenase-2 was observed in all living layers of psoriatic lesions. Actinic keratosis and squamous cell carcinomas showed a variable immunostaining pattern for 15-lipoxygenase-2. These results indicate that 15-lipoxygenase-2 is implicated in interferon-gamma-induced inflammatory processes in normal human epidermal keratinocytes and psoriatic skin.

A case of infectious eccrine hidradenitis.

We report a case of "infectious" neutrophilic eccrine hidradenitis who developed papules on the upper arm and trunk. Histological findings revealed vacuolar degeneration and necrosis of epithelial cells in the eccrine sweat ducts and neutrophils that had migrated through ductal epithelium to the lumen. A microabscess was also seen in the eccrine sweat gland coil. Our patient had received no chemotherapy such as cytarabine. Gram-positive cocci were present in the lesional eccrine duct indicating an infective origin of the disease. Human beta defensin-2, one of epithelial antimicrobial peptides, was present in the lesional epidermis and eccrine duct.

Effect of formaldehyde gas exposure in a murine allergic contact hypersensitivity model.

To clarify the effect of formaldehyde (FA) gas exposure on contact hypersensitivity (CHS), CHS reactions against 2,4,6-trinitrochlorobenzene (TNCB) was studied in BALB/c mice with a low dose of FA gas exposure. The TNCB-induced CHS reactions were slightly suppressed by the FA gas exposure immediately after sensitization, whereas they were significantly enhanced and prolonged in mice continuously exposed to FA gas before and after sensitization. We showed that exposure to FA gas enhanced the Th2 dominant responses in draining lymph node (LN) in early stage of CHS. In contrast, T cell subsets and their intracellular cytokine production in the draining LN were similar during the early stage of CHS by FA gas exposure during the sensitization phase. The percentage of CD8+ T cells was increased, and the percentage of CD4+CD25+ T cells was decreased in the FA gas-exposed group at 72 hr after elicitation. These results indicate that FA gas-exposed might influence regulatory T cells. Furthermore, in the chronic CHS model that was repetitively elicited with TNCB, more intensive and prolonged CHS reactions, and increased numbers of mast cells were found in the FA gas-exposed group at 4 hr after elicitation than in the control group, FA gas exposure may alter the intensity of allergic CHS.

Bullous Systemic Lupus Erythematosus as an Initial Manifestation of SLE.

Bullous systemic lupus erythematosus (BSLE) is a rare subset of systemic lupus erythematosus that is often associated with autoimmunity to type VII collagen. We describe a 45-year-old woman with BSLE who presented with vesiculobullous lesions as an initial manifestation of SLE. The patient first noticed a widespread urticarial, erythematous eruption associated with tense blisters, erosions, and crusting. She was diagnosed with bullous pemphigoid and underwent a one-month course of treatment with betamethazone. Because of the appearance of marked proteinuria, a subsequent renal biopsy, and serological tests, the patient was diagnosed with rapidly progressive glomerulonephritis and systemic lupus erythematosus. The patient's IgG circulating antibodies labeled the dermal floor of salt-split skin and recognized type VII collagen in immunoblot studies. Although methylprednisolone pulse therapy for glomerulonephritis did not alleviate the vesicullobullous eruption, treatment with dapsone resulted in dramatic disappearance of the lesions. Cessation of dapsone therapy due to hemolysis with Heinz-body formation did not aggravate the bullous disease. Our case illustrates that a generalized vesiculobullous eruption can be the sole presenting manifestation of SLE. It also emphasizes the close temporal relationship between BSLE and lupus nephritis.

A spectrum of clinical manifestations caused by host immune responses against Epstein-Barr virus infections.

Epstein-Barr virus (EBV), or human herpesvirus 4 (HHV-4), infects the vast majority of adults worldwide, and establishes both nonproductive (latent) and productive (lytic) infections. Host immune responses directed against both the lytic and latent cycle-associated EBV antigens induce a diversity of clinical symptoms in patients with chronic active EBV infections who usually contain an oligoclonal pool of EBV-infected lymphocyte subsets in their blood. Episomal EBV genes in the latent infection utilize an array of evasion strategies from host immune responses: the minimized expression of EBV antigens targeted by host cytotoxic T lymphocytes (CTLs), the down-regulation of cell adhesion molecule expression, and the release of virokines to inhibit the host CTLs. The oncogenic role of latent EBV infection is not yet fully understood, but latent membrane proteins (LMPs) expressed during the latency cycle have essential biological properties leading to cellular gene expression and immortalization, and EBV-encoded gene products such as viral interleukin-10 (vIL-10) and bcl-2 homologue function to survive the EBV-infected cells. The subsequent oncogenic DNA damage may lead to the development of neoplasms. EBV-associated NK/T cell lymphoproliferative disorders are prevalent in Asia, but quite rare in Western countries. The genetic immunological background, therefore, is closely linked to the development of EBV-associated neoplasms.

Minimal change nephrotic syndrome developing during postoperative interferon-beta therapy for malignant melanoma.

A 64-year-old man presented with proteinuria during postoperative interferon (IFN)-beta therapy against malignant melanoma. Renal pathologic findings were consistent with minimal change nephrotic syndrome (MCNS) showing extensive foot process effacement of visceral glomerular epithelial cells (podocyte). Nephrotic range proteinuria gradually regressed after stoppage of local injection of IFN-beta without glucocorticoid treatment. To our knowledge this is the first report that demonstrates histological abnormalities of the glomerulus associated with postoperative IFN-beta therapy for the malignant melanoma.