Chikako Yasui

HTLV-I-associated myelopathy in a patient with adult T-cell leukemia

Disseminated erythematous papules and plaques developed in a 60-year-old man 3 years before the appearance of neurologic manifestations. A biopsy specimen of the plaque revealed Pautriers microabscess and a dense mononuclear cell infiltration with atypical convoluted nuclei in the papillary dermis. These cells were helper/inducer T lymphocytes that expressed the interleukin 2 receptor. The patients white blood cell count was normal, but 1% atypical lymphocytes and a high titer of anti-human T-lymphotropic virus (HTLV)-I antibody were detected in his serum. A smoldering type of adult T-cell leukemia was diagnosed. While he was being treated with PUVA, a gait disturbance developed. A high titer of anti-HTLV-I antibody, characteristic of HTLV-I-associated myelopathy, was demonstrated in his cerebrospinal fluid.

Substance P induces inositol 1,4,5-trisphosphate and intracellular free calcium increase in cultured normal human epidermal keratinocytes.

Abstract Substance P is a neuropeptide which is present in peripheral C nerve endings and released from them. Free nerve endings of C nerve are present in human epidermis. The effects of substance P on the transmembrane signaling system of pig epidermal sheets were previously reported. In these studies, a small amount of cells other than keratinocytes contaminated the epidermal sheets and the species difference from human was also noticed. Therefore we investigated the effects of substance P on cultured normal human epidermal keratinocytes. Alteration of intracellular free calcium (Ca2+) in single living keratinocytes was studied using an inverted fluorescence microscope and Ca2+ ‐sensitive dye, Fura 2‐AM. Treatment of normal human epidermal kertinocytes with substance P resulted in an increase in inositol 1,4,5‐trisphosphate and in intracellular Ca2+. Substance P inhibited DNA synthesis of the keratinocytes in a dose‐dependent manner. These results are consistent with the view that substance P stimulates phosphatidylinositol‐4,5‐bisphosphate hydrolysis of human keratinocytes, resulting in inositol 1,4,5‐trisphosphate‐Ca2+ signal.

Adenylate cyclase induces intracellular Ca2+ increase in single human epidermal keratinocytes of the epidermal sheet as measured by digital imaging microscopy using Fura 2-AM

SummaryIntracellular Ca2+ ([Ca2+]i) is thought to act as a second messenger of transmembrane signalling systems. However, no measurement of [Ca2+]i has been made in intact epidermal keratinocytes. We have developed a method for measuring [Ca2+]i in human keratinocytes from pure epidermal sheet by the application of digital imaging fluorescence microscopy with the use of Fura 2-AM. Normal human pure epidermal sheets were obtained by dispase treatment. Epinephrine and salbutamol induced transient [Ca2+]i increases. Propranolol, a Β-antagonist, inhibited this response, while prazosin and yohimbine (alpha1- and alpha2-antagonists, respectively) did not affect the response. Histamine and adenosine, also receptor agonists of the epidermal adenylate cyclase system, induced a similar [Ca2+]i increase, as did forskolin, a direct activator of adenylate cyclase. These data coincide with those previously presented for cultured human epidermal keratinocytes, and reveal that adenylate cyclase activation induces an increase of [Ca2+]i in intact epidermal cells. This technique enables the kinetics of [Ca2+]i in various skin disorders to be investigated.

Adenylate cyclase induces intracellular calcium increase in single human epidermal keratinocytes measured by fluorescence microscopy using Fura 2-AM.

Intracellular calcium ([Ca2+]i) is an important second messenger of extracellular signals to induce various cellular responses. Extracellular and intracellular Ca2+ are considered to be important for cellular differentiation and proliferation of epidermal keratinocytes. Several mechanisms which increase [Ca2+]i have been demonstrated in various tissues, but in epidermal keratinocytes these mechanisms are poorly understood. In epidermal keratinocytes the adenylate cyclase‐cyclic AMP response is thought to regulate cell proliferation and differentiation. However, the series of reactions which follow the cyclic AMP response remain unknown. Beta‐adrenergic agonists increase [Ca2+]i in cultured epidermal keratinocytes, and we have therefore studied whether stimulation of keratinocyte adenylate cyclase could induce [Ca2+]i increase, by using fluorescence microscopy with Fura 2‐AM.

Translocation of protein kinase C from cytosol to membrane fractions in human epidermal keratinocytes by recombinant human interferon-gamma

The activation of protein kinase C involves its translocation from a cytosol fraction to a membrane fraction. Effects of interferon-gamma (IFN-gamma) on the epidermal protein kinase C were investigated. The treatment of recombinant human IFN-gamma on intact human epidermis resulted in the translocation of protein kinase C from a cytosol to a membrane fraction. The human IFN-gamma had no translocation effect on pig epidermal protein kinase C. Tumor promoter, 12-o-tetradecanoylphorbol-13-acetate (TPA), and a membrane-permeable diacylglycerol analogue, 1-oleoyl-2-acetylglycerol (OAG), both of which are well-known activators of protein kinase C, translocated the epidermal protein kinase C. The IFN-gamma had no direct effect on the epidermal protein kinase C; the addition of the IFN-gamma to partially-purified pig epidermal protein kinase C had no effect on its activity. The effect of the IFN-gamma on human epidermal protein kinase C appears to be through the species specific IFN-gamma receptors. It has been reported that the epidermal beta-adrenergic adenylate cyclase response is decreased following the TPA- (and OAG-) induced activation of protein kinase C. Human recombinant IFN-gamma, however, had no effect on the beta-adrenergic response of the human epidermis. Our results indicate that IFN-gamma affects intact keratinocytes in vitro, resulting in the activation of protein kinase C, which might be related to the physiological effect of IFN-gamma on keratinocyte.

Stimulation of prostaglandin E adenylate cyclase response in pig epidermis by hydrocortisone

Psoriatic involved epidermis is characterized by a defective beta-adrenergic adenylate cyclase response [5, 6, 9]. Using pig skin organ culture in vitro, previous findings show that various antipsoriatic and antimetabolic agents augment the beta-adrenergic adenylate cyclase response of epidermis. These chemicals include hydrocortisone, colchicine, Ro 10-1670 (Etretin), mepacrine, actinomycin D, and puromycin [8, 10, 11]. The effects of these chemicals on the prostaglandin E adenylate cyclase response have not been studied because of the weak response in pig skin epidermis. It is interesting to note that besides the beta-adrenergic response, the prostaglandin E response is also defective in psoriatic hyperproliferative epidermis [i, 3]. Therefore, we investigated the effect of various antipsoriatic and antimetabolic agents on the epidermal prostaglandin E adenylate cyclase response. The epidermal slices were obtained from pigs weighing about 10 kg with a Castroviejo keratome set at a depth of 0.2 mm. The epidermal slices were cut into 5 x 5 mm squares and rinsed three times. Then they were floated with the keratin layers up on RPMI medium 1640 with antibiotics (0.1 mg/ml streptomycin, 100 U/ml penicillin, and 0.25 gg/ml fungizone) containing the agents to be tested. After a 24-h incubation period at 37~ in an atmosphere of 5% CO2 in air, the epidermal slices were transferred on new RPMI medium where they were incubated for cyclic AMP accumulation studies. The specimens were incubated for 5 rain at 37~ on a water bath with either

Exacerbation of pemphigus foliaceus after electron-beam radiation.

© 2014 The Authors. doi: 10.2340/00015555-1811 Journal Compilation