Masashi Akiyama

Harlequin ichthyosis (HI) is a devastating skin disorder with an unknown underlying cause. Abnormal keratinocyte lamellar granules (LGs) are a hallmark of HI skin. ABCA12 is a member of the ATP-binding cassette transporter family, and members of the ABCA subfamily are known to have closely related functions as lipid transporters. ABCA3 is involved in lipid secretion via LGs from alveolar type II cells, and missense mutations in ABCA12 have been reported to cause lamellar ichthyosis type 2, a mil

mPer1, a mouse gene, is a homolog of the Drosophila clock gene period and has been shown to be closely associated with the light-induced resetting of a mammalian circadian clock. To investigate whether the rapid induction of mPer1 after light exposure is necessary for light-induced phase shifting, we injected an antisense phosphotioate oligonucleotide (ODN) to mPer1 mRNA into the cerebral ventricle. Light-induced phase delay of locomotor activity at CT16 was significantly inhibited when the mice

Generalized pustular psoriasis (GPP) is a rare disease characterized by recurrent fever and systemic flushing accompanied by extensive sterile pustules. The committee of the guidelines was founded as a collaborative project between the Japanese Dermatological Association and the Study Group for Rare Intractable Skin Diseases under the Ministry of Health, Labour, and Welfare Research Project on Overcoming Intractable Diseases. The aim of the guidelines was to provide current information to aid in

Daily restricted feeding (RF) produces an anticipatory locomotor activity rhythm and entrains the peripheral molecular oscillator independently of the central pacemaker located in the suprachiasmatic nucleus (SCN). As orexins (hypocretins) are neuropeptides that coordinate sleep/wake patterns and motivated behaviours, such as food seeking, we studied the involvement of orexin in the food anticipatory activity (FAA) induced by RF. Daily RF shifted the mRNA rhythm of a clock-controlled gene mDbp i

ADAMTS13 specifically cleaves plasma von Willebrand factor (VWF) and thereby controls VWF-mediated platelet thrombus formation. Severe deficiencies in ADAMTS13 can cause life-threatening thrombotic thrombocytopenic purpura. Here, we determined 2 crystal structures of ADAMTS13-DTCS (residues 287-685), an exosite-containing human ADAMTS13 fragment, at 2.6-A and 2.8-A resolution. The structures revealed folding similarities between the disintegrin-like (D) domain and the N-terminal portion of the c

Filaggrin is a key protein involved in skin barrier function. Mutations in the gene encoding filaggrin (FLG) have been identified as the cause of ichthyosis vulgaris and have been shown to be major predisposing factors for atopic eczema (AE), initially in European populations. Subsequently, FLG mutations were identified in Japanese, Chinese, Taiwanese and Korean populations. It was demonstrated that FLG mutations are closely associated with AE in the Japanese population. Notably, the same FLG mu

Mutations in ABCA12 have been described in autosomal recessive congenital ichthyoses (ARCI) including harlequin ichthyosis (HI), congenital ichthyosiform erythroderma (CIE), and lamellar ichthyosis (LI). HI shows the most severe phenotype. CIE and LI are clinically characterized by fine, whitish scales on a background of erythematous skin, and large, thick, dark scales over the entire body without serious background erythroderma, respectively. To date, a total of 56 ABCA12 mutations have been re