Syringotropic and pilotropic cutaneous T-cell lymphoma without follicular mucinosis

BACKGROUND: Mycosis fongoides rarely exhibits predilection for infiltration of hair follicles and eccrine glands. We report the case of a patient with cutaneous T-cell lymphoma with syringotropism and pilotropism without follicular mucinosis. CASE REPORT: A 51-year-old man presented with erythematous infiltrated patches with alopecia and anhydrosis, cystic lesions, comedon-like lesions, follicular keratosis and an ulcer over the lower left leg. Clinical examination revealed no palpable adenopathy or hepatosplenomegaly. The patient complained about hypohydrosis. Histological examination of skin biopsies evidenced pilotropic cutaneous T-cell lymphoma without follicular mucinosis. Immunohistological examination and T-cell receptor B-chain gene rearrangement analysis showed a clonal population of T-cells. Moreover sweat glands and sweat ducts were infiltrated by atypical lymphocytes with syringolymphoid hyperplasia. DISCUSSION: Syringolymphoid hyperplasia and folliculotropism without follicular mucinosis are rarely seen in mycosis fongoides. Deep biopsies of adnexal structures are required for this critical diagnosis and clonal rearrangement of TCR genes is a reliable means of assessing clonality. Syringolymphoid hyperplasia and pilotropism without mucinosis are variants of cutaneous T-cell lymphomas

Protective effects of antioxidants against UVA-induced DNA damage in human skin fibroblasts in culture

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Does manganese protect cultured human skin fibroblasts against oxidative injury by UVA, dithranol and hydrogen peroxide?

Reactive oxygen species (ROS) are involved in the mechanism of photoaging and carcinogenesis. Skin is endowed with antioxidant enzymes including superoxide dismutases (SOD): cytosolic copper zinc SOD and mitochondrial manganese SOD. The aim of our study was to estimate the protective effect of manganese against oxidative injury on cultured human skin fibroblasts. Dithranol, hydrogen peroxide and UV-A radiation (375 nm) were employed as oxidative stressors. The supply of manganese chloride produced an increase in cellular content of this element up to 24 fold without concomitant elevation of MnSOD activity. Nevertheless, manganese protects cells against two of the three ROS generating systems assessed, namely hydrogen peroxyde and UV-A. This protective effect depends on the concentration of manganese in the medium, 0.1 mM and 0.2 mM protect against UVA cytotoxicity, only 0.2 mM protects against H2O2 cytotoxicity

Impairment of cultured cell proliferation and metallothionein expression by metal chelator NNN'N'-tetrakis-(2-pyridylmethyl)ethylene diamine

Metallothioneins (MT) are a family of intracellular, cysteine-rich, zinc-binding proteins. Their expression is constitutive but can also be induced at the transcriptional level by various stimuli. In this study, we exposed HaCaT human keratinocytes to excess zinc (ZnCl2) or to zinc deprivation by the diffusible chelator NNN'N'-tetrakis(2-pyridyl-methyl)ethylene diamine (TPEN), and to ultraviolet B (UVB) irradiation. We examined both cell proliferation and MT expression. Cell proliferation was maximally stimulated by 100 mu M Zn2+ supply and was markedly inhibited by zinc deprivation or UVB irradiation. Zinc and UVB irradiation both increased MTI and/or MTII as detected by immunocytochemistry and enhanced the baseline level of MT-IIA mRNA, whereas TPEN treatment inhibited MT basal expression. Zinc partially prevented the concentration-dependent, UVB-induced decrease in cell proliferation. On the other hand, TPEN partially prevented the UVB-induced increase in MTIIA mRNA. These results suggest that zinc is involved in defense mechanisms of skin keratinocytes and in their stress-induced response

Metal chelator NNN'N'-tetrakis-(2-pyridylmethyl)ethylene diamine inhibits the induction of heat shock protein 70 synthesis by heat in cultured keratinocytes

Heat shock protein (HSP) synthesis results from various types of injury, including heat shock (HS) and some oxidants. The intracellular signals leading to HSP synthesis are not yet fully elucidated. We have studied the influence of NNN' N'-tetrakis(2-pyridylmethyl)ethylene diamine (TPEN), a metal chelator known to induce cellular zinc and copper deprivation, on resistance to heat and on hsp70 synthesis in HaCaT keratinocytes. TPEN was shown to sensitize HaCaT cells to heat shock. The effect of TPEN was neutralized by equimolar Zn2+ By the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and Western blotting characterization of hsp70, it was shown that cultured HaCaT cells constitutively express the inducible form of hsp70. The application of TPEN alone slightly increases the level of hsp70 but inhibits its induction by HS. This inhibitory effect is related to metal deprivation, because it is eliminated when Cu2+ Or Zn2+ ions are supplied together with TPEN. These results suggest that these metals are involved in the expression by keratinocytes of a stress protein which has a protective action against environmental stress

Involvement of zinc in intracellular oxidant/antioxidant balance

The effect of zinc (Zn) on cellular oxidative metabolism is complex and could be explained by multiple complementary interactions. In this study, we evaluated the impact of Zn on the pro-oxidant/antioxidant balance of HaCaT keratinocytes