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Biomedical subjects

M Ichihashi

Publications and source records attributed to M Ichihashi.

At least 19 recordsLinked to original sources
PubMed2002

Protean manifestations of human papillomavirus type 60 infection on the extremities.

BACKGROUND: Human papillomavirus type 60 (HPV-60) induces a ridged wart or an epidermal cyst on the sole of the foot, exhibiting identical pathological changes, with a single refractile eosinophilic intracytoplasmic inclusion body in infected cells. However, there is no information on the role of HPV-60 in the development of cutaneous lesions on other anatomical sites. OBJECTIVES: To perform the clinicopathological analysis of various cutaneous lesions of a patient in relation to HPV genotype. PATIENT: A 50-year-old male patient developed multiple papules, plaques and nodules on his hand, arm and legs. RESULTS: Clinicopathologically, the lesions were classified into three categories. A common wart on the finger showed papillomatosis and acanthosis characterized by numerous keratohyalin granules. Plane warts on the arm showed perinuclear vacuolization of the cells in the upper Malpighian layer. On the other hand, a pigmented papillomatous nodule on the finger, and the other lesions on the hands and legs exhibited similar histological features with a unique cytoplasmic eosinophilic inclusion body. All the three categorized lesions were equally positive for HPV capsid antigen by immunohistochemistry. By blot hybridization analysis for HPV sequences, it was revealed that a common wart on the finger and plane warts on the arm harboured HPV-27 and HPV-3, respectively, while all the other lesions harboured HPV-60. The histological localization of each viral DNA was confirmed in the corresponding lesions by in situ hybridization. CONCLUSIONS: HPV-60 is able to induce papular and nodular lesions on the extremities.

Arm↗
PubMed2001

UV-induced tyrosine phosphorylation of PKC delta and promotion of apoptosis in the HaCaT cell line.

Protein kinase C delta (PKC delta) is activated through tyrosine phosphorylation and is involved in apoptosis induction in the H(2)O(2)-treated fibroblasts. In the human keratinocyte HaCaT cell line, ultraviolet radiation, which induces apoptosis, promoted tyrosine phosphorylation and activation of PKC delta, but neither enhanced threonine phosphorylation in the activation loop nor generated the catalytic fragment of the PKC isoform. Tyrosine phosphorylation of PKC delta was prevented by a radical scavenger, N-acetyl-l-cysteine, and by a tyrosine kinase inhibitor, genistein, in the ultraviolet-irradiated keratinocyte cell line. Ultraviolet radiation-induced apoptosis was attenuated by N-acetyl-l-cysteine and genistein as well as by a PKC inhibitor, bisindolylmaleimide I. These results indicate that reactive oxygen species generated by ultraviolet radiation enhance tyrosine phosphorylation of PKC delta, and the PKC isoform thus activated by the modification reaction contributes to induction of apoptotic cell death in keratinocytes.

Antineoplastic Agents↗
PubMed2001

Low-dose ultraviolet B radiation synergizes with TNF-alpha to induce apoptosis of keratinocytes.

High-dose ultraviolet B (UVB) irradiation is known to induce apoptosis of keratinocytes, but low-dose UVB dose not. In this paper we present evidence that low-dose UVB can induce TNF-alpha-dependent apoptosis of keratinocytes. In our study, 5 mJ/cm(2) doses of UVB were not sufficient by themselves to induce apoptosis of cultured human keratinocytes, but 20 mJ/cm(2) doses of UVB were. The combination of 5 mJ/cm(2) doses of UVB and exogenous TNF-alpha (15 ng/ml) induced significant apoptosis of keratinocytes, although exogenous TNF-alpha without UVB did not. This phenomenon was accompanied by enhanced clustering of tumor necrosis factor receptor 1 (TNFR1). TNF-alpha's promotion of the induction of apoptosis by low-dose UVB was seen until 30 min after irradiation but not at 1 h. We confirmed this finding using a skin organ culture system. UVB (20 mJ/cm(2)), which did not induce transformation of epidermal keratinocytes into sunburn cells, induced apoptosis when TNF-alpha was added to the culture medium. These results suggest that one of the possible mechanisms of inducing keratinocyte apoptosis by low-dose UVB and TNF-alpha is that low-dose UVB augments ligand-binding-induced TNFR1 clustering, resulting in increased apoptotic cell death.

Antigens, CD↗
PubMed2001

Epidermal changes caused by chronic low-dose UV irradiation induce wrinkle formation in hairless mouse.

To investigate the effects of chronic low-dose UV irradiation on the skin, hairless mice were irradiated with a 1/3 minimal erythemal dose (MED) of UV. We examined the relationship between visible changes and skin damage in the dermis and epidermis. Hairless mice were irradiated with UVB (20 mJ/cm2) and UVA (14 J/cm2) three times a week for 10 weeks, followed by a 24-week non-irradiation period. Visible fine wrinkling was present after 4 weeks of irradiation, and the wrinkling progressively worsened throughout the period of irradiation. The wrinkles remained after irradiation was discontinued. In dermal components, no significant histological changes in the collagen fibers and elastic fibers were found, and the amount of hydroxyproline was also not changed. Thus, in the epidermis, there was a significant increase in the number of stratum corneum layers and the terminal-differentiation marker, filaggrin, positive cells. The intensity of staining for the differentiation marker, keratin 1, was reduced. These changes were accompanied by wrinkle formation, and remained after discontinuance of irradiation. These findings suggested that chronic low-dose UV irradiation induces structural and quantitative changes in the epidermis as a result of keratinization impairment, and that this damage in the epidermis is an important causative factor in wrinkle formation.

Animals↗
PubMed2001

Quantitative evaluation of skin condition in an epidemiological survey of females living in northern versus southern Japan.

Image analysis and biophysical methods were used to compare the skin condition of a group of females ranging in age from 5 to 65 years who had lived all of their lives in either Kagoshima (n=300), located in southern Japan, or Akita (n=302), located in northern Japan. Kagoshima annually receives approximately 1.5 times more solar UVB radiation than Akita. The methods used and corresponding skin parameters reported in this survey were: high resolution digital imaging followed by computer analysis of facial images for facial skin wrinkling and hyperpigmentation; silicone skin replicas followed by Moiré interferometry for facial skin surface roughness (texture); the Minolta Chromameter for skin color (L*a*b*) on sun-exposed (forehead) and sun-protected (upper inner arm) skin sites; the Corneometer for skin capacitance (hydration) on the cheek and ventral forearm; the Sebumeter for sebum excretion rate on the forehead; and the Minolta Spot Thermometer for skin temperature on the upper cheek. Compared with Japanese women living in Akita, Japanese women living in Kagoshima had significantly longer facial wrinkles, higher number of wrinkles, larger hyperpigmented spots, higher number of spots, rougher facial skin texture, more yellow foreheads and upper inner arms, darker foreheads, and less stratum corneum hydration in the cheeks and arms. When compared on an age-for-age basis, the average 40-year-old Kagoshima women has the same level of facial wrinkling as a 48-year-old Akita women, a delay of 8 years for living in the northern latitude. For facial hyperpigmentation, the delay is 16 years; the average 40-year-old Kagoshima women has the same level of facial hyperpigmentation as a 56-year-old Akita women. The results further testify to the skin damaging effects of sun exposure and may be useful in public health education to promote everyday sun protection.

Adolescent↗
PubMed2001

The efficacy of glycolic acid for treating wrinkles: analysis using newly developed facial imaging systems equipped with fluorescent illumination.

The clinical characteristics of photodamaged skin, such as coarse and fine wrinkling, can not be quantitatively evaluated from ordinary photographic records. The purpose of this study was to assess the efficacy of glycolic acid (GA) peeling on facial wrinkling, using computer assisted image analysis. This was accomplished with reproducible imaging techniques, which allowed precise repositioning of the subject's face in front of the camera. Two parameters, the change in wrinkle number and the change in wrinkle length were assessed. Although the clinical improvement of wrinkles correlated with both parameters, wrinkle length more precisely reflected the degree of clinical wrinkles, because the wrinkle number appeared to increase as some shallow wrinkles divided into multiple smaller wrinkles during their improvement. Comparison of responses by different age groups showed that the reduction of total wrinkle length was observed in the order of: 50s>30s and 40s>60s>over 70>under 30. The lack of response by subjects over 70 might be due to the nature of their wrinkles being mainly coarse wrinkles rather than fine ones. We next compared the effect of GA by concentration (35, 50 or 70%), but found no significant differences. As the concentration of GA used for treatment was determined by each subject's erythema reaction, our present result suggests that erythema elicited by GA correlates with improvement of wrinkles and that these two phenomena can be induced by a common pathway of GA treatment. This quantitative analysis clearly shows the efficacy and limitation of GA treatment of wrinkles, and might help to disclose the precise mechanisms of GA effects on the skin structure and function.

Adult↗
PubMed2001

Tissue factor expression and serum level in patients with melanoma does not correlate with disease progression.

Not only does tissue factor (TF) play a crucial role in hemostasis and thrombosis, but it is also involved in tumor progression and metastatic potency in some malignant tumors. We evaluated the clinical relevance of TF expression in melanocytic tumors and TF serum level in patients with malignant melanoma. TF expression in benign and malignant melanocytic lesions was examined by immunoperoxidase staining in 20 nevi, 41 primary, and 24 metastatic melanoma lesions. TF was detected in 94, 95, and 100% of these lesions, respectively. The staining pattern was membranous and cytoplasmic both in nevi and melanoma cells. This finding was confirmed by western blot analysis using cultured human melanocytes, nevi cells, and melanoma cell lines. TF was also expressed on blood vessels in benign and malignant melanocytic lesions. Expression of TF in primary melanoma lesions was not associated with any clinicopathological variables. In addition, the serum level of TF was elevated in 14% of patients with melanoma; however, it was not correlated with disease progression. These results suggest that TF was ubiquitously expressed in melanocytic cells and its expression was not correlated with disease progression and/or metastatic potency of melanoma cells.

Adolescent↗
PubMed2001

The effect of thioredoxin on the expression of proopiomelanocortin-derived peptides, the melanocortin 1 receptor and cell survival of normal human keratinocytes.

An important constituent of the cellular antioxidant buffering system that controls the redox state of proteins is thioredoxin (TRX), a 13 kDa protein that catalyzes thiol-disulfide exchange reactions, regulates activation of transcription factors, and possesses several other biologic functions similar to cytokines. We have previously reported that TRX released from UVB-irradiated keratinocytes stimulates melanogenesis by upregulating MSH receptor expression and its binding activity in melanocytes. The purpose of this study was to examine the effects of TRX on keratinocytes as an autocrine factor. TRX suppressed the UVB-induced production and secretion of alpha-melanocyte stimulating hormone (alpha-MSH) and of adrenocorticotropic hormone (ACTH), and also suppressed proopiomelanocortin (POMC) mRNA expression by normal human keratinocytes; however, TRX upregulated melanocortin 1 receptor (MC1-R) expression synergistically with UVB in normal human keratinocytes. These results suggest that exogenous TRX regulates expression of those genes in different manners. Furthermore, addition of an antibody against TRX induced cell death in keratinocytes, probably due to enhanced signaling of MSH, as it has been shown that MSH suppresses heat shock protein (hsp) 70 expression in differentiated keratinocytes, which express high levels of MC1-R and decreases their survival rate during oxidative stress. Taken together, the results suggest that keratinocyte-derived TRX regulates the expression of stress inducible neuropeptides and their receptor, and is critically involved in the survival of keratinocytes.

Acetylcysteine↗
PubMed2001

Aspirin enhances the induction of type I allergic symptoms when combined with food and exercise in patients with food-dependent exercise-induced anaphylaxis.

We examined the effect of aspirin as a substitute for exercise in inducing urticaria/anaphylaxis in three patients with food-dependent exercise-induced anaphylaxis (FDEIA). Two of the patients had specific IgE antibodies to wheat and the other had antibodies to shrimp. Administration of aspirin before ingestion of food allergens induced urticaria in one patient and urticaria and hypotension in another, while aspirin alone or food alone elicited no response. The third patient developed urticaria only when he took all three items, i.e. aspirin, food and additional exercise, whereas provocation with any one or or two of these did not induce any symptoms. These findings suggest that aspirin upregulates type I allergic responses to food in patients with FDEIA, and further shows that aspirin synergizes with exercise to provoke symptoms of FDEIA. This is the first report of a synergistic effect of aspirin in inducing urticaria/anaphylaxis, which was confirmed using challenge tests in patients with FDEIA.

Adolescent↗
PubMed2001

Regulation of Ras and Rho small G proteins by SHP-2.

BACKGROUND: Hepatocyte growth factor/scatter factor (HGF/SF) induces cell scattering through the tyrosine kinase-type HGF/SF receptor, c-Met. We have previously shown that SHP-2, a protein tyrosine phosphatase, positively regulates the HGF/SF-induced cell scattering through modulating the activity of Rho to form stress fibres and focal adhesions. To further investigate the role of SHP-2 in HGF/SF-induced cell scattering, we have now examined the effect of a dominant active mutant of SHP-2 (SHP-2-DA). RESULTS: Expression of SHP-2-DA markedly increased the formation of lamellipodia with ruffles, while it decreased the accumulation of E-cadherin and beta-catenin at cell-cell adhesion sites in MDCK cells. In addition, expression of SHP-2-DA markedly enhanced cell scattering of MDCK cells in response to HGF/SF. Expression of SHP-2-DA induced the activation of MAP kinase without HGF/SF stimulation, whereas an inhibitor of MEK partly reversed the SHP-2-DA-induced morphological phenotypes. Furthermore, expression of either a dominant-active mutant of Rho or Vav2 also reversed the SHP-2-DA-induced morphological phenotypes. CONCLUSION: These results indicate that SHP-2 plays a crucial role in the HGF/SF-induced cell scattering through the regulation of two distinct small G proteins, Ras and Rho.

Animals↗
PubMed2001

Secreted type of modified interleukin-18 gene transduced into mouse renal cell carcinoma cells induces systemic tumor immunity.

PURPOSE: Interleukin (IL)-18 is a novel cytokine that has been identified as a strong interferon-gamma inducer. IL-18 has bioactivity similar to that of IL-12 and demonstrates antitumor effects. Since IL-18 does not have a signal sequence, we constructed the gene, consisting of the signal sequences of interferon-beta and mature IL-18 complementary (c) DNA. The modified gene was subsequently transduced into a mouse renal cell carcinoma cell line to induce IL-18 secretion from tumor cells to establish whether this IL-18 secreting tumor cell line may induce systemic tumor immunity. MATERIALS AND METHODS: Modified IL-18 cDNA consisting of the signal sequences of interferon-beta and mature type of IL-18 cDNA was constructed by the overlap extension method. The modified and original IL-18 cDNA was transduced into the RenCa mouse renal cell carcinoma cell line. Expression of IL-18 messenger RNA and concentration of IL-18 in the culture supernatant were determined. Direct antitumor and tumor vaccine effects were investigated in syngeneic Balb/c mice. To determine the mechanism of the antitumor effect immunodeficient mice were challenged with IL-18 secreting RenCa cells. RESULTS: Although the modified and original IL-18 genes transduced RenCa showed almost the same level of IL-18 messenger RNA expression, only RenCa cells transduced with modified IL-18 gene secreted IL-18 into the culture supernatant and were completely rejected when transplanted into syngeneic mice. T lymphocytes were involved in this antitumor effect. Moreover, the modified IL-18 transduced RenCa induced tumor vaccine effect against parental RenCa cells injected at a distant site. CONCLUSIONS: Immune gene therapy using modified IL-18 cDNA appears to be effective and IL-18 secreting cancer cells may be a candidate for tumor vaccine therapy.

Animals↗
PubMed2001

Inhibition of the motility and growth of B16F10 mouse melanoma cells by dominant negative mutants of Dok-1.

Dok-1 (p62(Dok)) is a multiple-site docking protein that acts downstream of receptor and nonreceptor tyrosine kinases. Although it has been proposed to contribute to the control of cell growth and migration through association with the Ras GTPase-activating protein and the adapter protein Nck, the role of Dok-1 remains largely unknown. The functions of Dok-1 have now been investigated by the generation of two different COOH-terminal truncation mutants of this protein: one (DokPH+PTB) containing the pleckstrin homology and phosphotyrosine-binding domains, and the other (DokPH) composed only of the pleckstrin homology domain. Both of these mutant proteins were shown to act in a dominant negative manner. Overexpression of each of the mutants in highly metastatic B16F10 mouse melanoma cells thus both inhibited the tyrosine phosphorylation of endogenous Dok-1 induced by cell adhesion as well as reduced the association of the endogenous protein with cellular membranes and the cytoskeleton. Overexpression of DokPH+PTB in these cells also markedly reduced both the rates of cell spreading, migration, and growth as well as the extent of Ras activation. The effects of DokPH on these processes were less pronounced than were those of DokPH+PTB, indicating the importance of the phosphotyrosine-binding domain. These results suggest that at least in B16F10 cells, Dok-1 positively regulates not only cell spreading and migration but also cell growth and Ras activity.

Animals↗
PubMed2001

Aberrant expression of MSG1 transcriptional activator in human malignant melanoma in vivo.

MSG1 was originally isolated as a candidate pigmentation-related gene. MSG1 mRNA transcripts were expressed strongly in cultured human and mouse normal epidermal melanocytes, and in highly pigmented mouse melanoma cells, while its expression was very weak in cultured non-pigmented human melanoma cells. Thus, MSG1 was initially proposed to be a melanocyte-specific gene, and its possible role in pigmentation has been speculated. It was found recently that the MSG1 protein interacts functionally with Smad4, which plays a pivotal role in signal transduction of transforming growth factor-beta. In this study, we analyzed MSG1 protein expression by immunohistochemistry using human tumor samples from nevus and malignant melanoma to reveal its role in pigmentation and melanoma development in vivo. A relatively strong but heterogeneous expression of MSG1 protein was seen in melanomas compared with weak expression in nevi. In nevi, MSG1 expression was mostly confined to the pigmented region, while it was expressed in both pigmented and non-pigmented regions in melanoma. Intracellularly, MSG1 protein was localized in the cytoplasm of nevus cells, but was seen in both nuclei and cytoplasm of melanoma cells. These results support a hypothesis that MSG1 plays a role in pigmentation. It is also suggested that MSG1 may be involved in malignant transformation of pigment cells. Alternatively, the aberrant expression of MSG1 in melanoma cells might be due to the abnormal environment, including aberrant cytokine or growth factor expression, associated with melanoma formation.

Apoptosis Regulatory Proteins↗
PubMed2001

Fusion hybrids with macrophage and melanoma cells up-regulate N-acetylglucosaminyltransferase V, beta1-6 branching, and metastasis.

It was shown previously that a majority of hybrids produced by in vitro fusion of normal macrophages with Cloudman S91 melanoma cells displayed enhanced metastatic potential in vivo, increased motility in vitro, increased ability to produce melanin, and responsiveness to melanocyte stimulating hormone compared with the parental Cloudman S91 melanoma cells. These hybrids also showed altered N-glycosylation consistent with a slower migration pattern of lysosome-associated membrane protein (LAMP-1) on electrophoretic gels. Because LAMP-1 is the major carrier of polylactosamine sugar structures, and synthesis of this complex sugar moiety indicates the extent of beta1,6 branch formation by beta1,6-N-acetyl-glucosaminyltransferase V (GnT-V), we analyzed the expression of GnT-V and beta1,6 branching in highly metastatic macrophage-fusion hybrids and compared with poorly metastatic ones. GnT-V was up-regulated in regard to both mRNA levels and enzymatic activity specifically in metastatic hybrids as well as parental macrophages compared with weakly metastatic hybrids and parental melanoma cells. Macrophages and metastatic hybrids also showed increased binding of the lectin L-phytohemagglutinin, which specifically binds to the beta1,6-branched sugar moiety. In addition, in metastatic hybrids there was increased cell surface expression of LAMP-1 and beta1 integrin, two prominent substrates for GnT-V also known to be associated with metastasis. Finally, exposure of metastatic hybrids in vitro to L-phytohemagglutinin or LAMP-1 completely eliminated melanocyte stimulating hormone/ isobutylmethyl xanthine-induced motility, suggesting a role for GnT-V in the motility of these cells. In summary, macrophage fusion with melanoma cells often increased metastatic potential, which was associated with enhanced expression of GnT-V and beta1,6-branching in glycoproteins. It is suggested that the known correlation with elevated GnT-V in both human and animal metastasis could, at least in some cases, reflect previous fusion of tumor cells with tumor-infiltrating macrophages, which, similar to malignant cells, show elevated expression of GnT-V and beta1,6-branched polylactosamines.

Animals↗
PubMed2000

CC to TT mutation in the mitochondrial DNA of normal skin: relationship to ultraviolet light exposure.

We have previously reported that ultraviolet (UV)-specific (CC to TT) mutations in p53 gene can be detected in normal skin. This, however, cannot be used as a cumulative marker of UV exposure, since cells with the p53 mutation acquire a clonal growth advantage. Moreover, a large skin biopsy is necessary for each assay. In order to circumvent these problems, we have measured mitochondrial (Mt) DNA mutations; there are more than 1000 copies of the Mt genome per cell, and Mt genes are not directly involved in cell growth. We have established a sensitive allele-specific polymerase chain reaction (AS-PCR) assay capable of detecting one CC to TT mutation in Mt DNA among 10(7) wild-type genes using a mismatch allele-specific primer. With this assay, we found no mutation-positive samples from internal non-exposed tissue (stomach, colon, and blood) (0/50). In contrast, 17 out of 111 skin samples were positive: the mutation frequency in positive samples was around 10(7)-10(-6) (10-100 copies of mutant in 10(8) wild-type Mt DNA). In normal skin tissue, the prevalence of positive samples was higher in those from exposed sites (13/51) than in those from less-exposed sites (1/26) (p<0.05). However, a quantitative correlation between sunlight exposure and the accumulation of mutations was not found. We conclude that the UV exposure-associated CC to TT mutation in Mt DNA can be detected in normal skin, but that further studies are required to develop this as a quantitative marker for UV exposure.

Aged↗