Haruo Kutsuna

Hematopoietic, angiogenic and eye defects in Meis1 mutant animals

Meis1 and Hoxa9 expression is upregulated by retroviral integration in murine myeloid leukemias and in human leukemias carrying MLL translocations. Both genes also cooperate to induce leukemia in a mouse leukemia acceleration assay, which can be explained, in part, by their physical interaction with each other as well as the PBX family of homeodomain proteins. Here we show that Meis1‐deficient embryos have partially duplicated retinas and smaller lenses than normal. They also fail to produce megakaryocytes, display extensive hemorrhaging, and die by embryonic day 14.5. In addition, Meis1‐deficient embryos lack well‐formed capillaries, although larger blood vessels are normal. Definitive myeloerythroid lineages are present in the mutant embryos, but the total numbers of colony‐forming cells are dramatically reduced. Mutant fetal liver cells also fail to radioprotect lethally irradiated animals and they compete poorly in repopulation assays even though they can repopulate all hematopoietic lineages. These and other studies showing that Meis1 is expressed at high levels in hematopoietic stem cells (HSCs) suggest that Meis1 may also be required for the proliferation/self‐renewal of the HSC.

Selective Activation of p38 Mitogen-Activated Protein Kinase Cascade in Human Neutrophils Stimulated by IL-1β

We investigated activation of mitogen-activated protein kinase (MAPK) subtype cascades in human neutrophils stimulated by IL-1β. IL-1β induced phosphorylation and activation of p38 MAPK and phosphorylation of MAPK kinase-3/6 (MKK3/6). Maximal activation of p38 MAPK was obtained by stimulation of cells with 300 U/ml IL-1β for 10 min. Extracellular signal-regulated kinase (ERK) was faintly phosphorylated and c-Jun N-terminal kinase (JNK) was not phosphorylated by IL-1β. IL-1β primed neutrophils for enhanced release of superoxide (O2−) stimulated by FMLP in parallel with increased phosphorylation of p38 MAPK. IL-1β also induced O2− release and up-regulation of CD11b and CD15, and both responses were inhibited by SB203580 (p38 MAPK inhibitor), suggesting that p38 MAPK activation mediates IL-1β-induced O2− release and up-regulation of CD11b and CD15. Combined stimulation of neutrophils with IL-1β and G-CSF, a selective activator of the ERK cascade, resulted in the additive effects when the priming effect and phosphorylation of p38 MAPK and ERK were assessed. IL-1β induced phosphorylation of ERK and JNK as well as p38 MAPK in human endothelial cells. These findings suggest that 1) in human neutrophils the MKK3/6-p38 MAPK cascade is selectively activated by IL-1β and activation of this cascade mediates IL-1β-induced O2− release and up-regulation of CD11b and CD15, and 2) the IL-1R-p38 MAPK pathway and the G-CSF receptor-ERK pathway work independently for activation of neutrophils.

Enhanced neutrophil motility by granulocyte colony‐stimulating factor: the role of extracellular signal‐regulated kinase and phosphatidylinositol 3‐kinase

The effect of granulocyte colony‐stimulating factor (G‐CSF) on human neutrophil motility was studied using videomicroscopy. Stimulation of neutrophils with G‐CSF resulted in enhanced motility with morphological change and increased adherence. Enhanced neutrophil motility was detected within 3–5 min after G‐CSF stimulation, reached a maximum at 10 min, and was sustained for approximately 35 min. The maximum migration rate was 84·4 ± 2·9 μm/5 min. A study using the Boyden chamber method revealed that G‐CSF‐stimulated neutrophils exhibited random migration but not chemotaxis. Enhanced neutrophil motility and morphological change were inhibited by MEK [mitogen‐activated protein kinase (MAPK)/extracellular signal‐regulated kinase (ERK) kinase] inhibitors (PD98059 and U0126), and a phosphatidylinositol 3‐kinase (PI3K) inhibitor (wortmannin), but not by a p38 MAPK inhibitor (SB203580). These findings are consistent with the fact that G‐CSF selectively activates MEK/ERK and PI3K, but not p38, in neutrophils. MEK/ERK activation was associated with G‐CSF‐induced redistribution of F‐actin and phosphorylated myosin light chain. Enhanced neutrophil motility was observed even in the presence of neutralizing anti‐CD18 antibody, which prevented cell adherence. These findings indicate that G‐CSF induces human neutrophil migration via activation of MEK/ERK and PI3K.

An Alternative Approach to Atopic Dermatitis: Part I—Case-Series Presentation

Atopic dermatitis (AD) is a complex disease of obscure pathogenesis. A substantial portion of AD patients treated with conventional therapy become intractable after several cycles of recurrence. Over the last 20 years we have developed an alternative approach to treat many of these patients by diet and Kampo herbal medicine. However, as our approach is highly individualized and the Kampo formulae sometimes complicated, it is not easy to provide evidence to establish usefulness of this approach. In this Review, to demonstrate the effectiveness of the method of individualized Kampo therapy, results are presented for a series of patients who had failed with conventional therapy but were treated afterwards in our institution. Based on these data, we contend that there exist a definite subgroup of AD patients in whom conventional therapy fails, but the ‘Diet and Kampo’ approach succeeds, to heal. Therefore, this approach should be considered seriously as a second-line treatment for AD patients. In the Discussion, we review the evidential status of the current conventional strategies for AD treatment in general, and then specifically discuss the possibility of integrating Kampo regimens into it, taking our case-series presented here as evidential basis. We emphasize that Kampo therapy for AD is more ‘art’ than technology, for which expertise is an essential pre-requisite.

An Alternative Approach to Atopic Dermatitis: Part II—Summary of Cases and Discussion

In the first part of this Review, we presented case-series where Kampo treatment was introduced for those atopic dermatitis (AD) patients who had failed with conventional therapy, in an attempt to prove that there exists a definite subgroup of AD patients for whom Kampo treatment is effective. In this second part, we will first provide the summary of the results for 140 AD patients we treated in 2000. The results suggest that Kampo treatment is effective for more than half of AD patients who fail with conventional therapy. In the Discussion, we will examine the evidential basis for conventional AD therapy and discuss how Kampo treatment should be integrated into the guidelines for AD therapy. We contend that Kampo treatment should be tried before systematic immunosuppressive agents are considered. As each Kampo treatment is highly individualized, it should be regarded more as ‘art’ than technology, and special care should be taken to assess its efficacy in clinical trial.

Cyclic AMP delays neutrophil apoptosis via stabilization of Mcl-1

Human neutrophils underwent spontaneous apoptosis, which was accompanied by degradation of Mcl‐1, but not other anti‐apoptotic molecules (cIAP1, cIAP2, A1, survivin and Bcl‐2). Spontaneous neutrophil apoptosis and Mcl‐1 degradation were prevented by cyclic AMP (cAMP) agonists (dibutyryl cAMP and prostaglandin E 1), and the effects of cAMP agonists on neutrophils were highly resistant to cycloheximide, a protein synthesis inhibitor, although slight increase in Mcl‐1 mRNA expression was induced by cAMP agonists. Proteasome inhibitors (epoxomicin and lactacystin) also prevented spontaneous neutrophil apoptosis and Mcl‐1 degradation to the same extent as cAMP agonists, and no additive effect was obtained by combination of cAMP agonists and proteasome inhibitors. These findings suggest that cAMP agonists, like proteasome inhibitors, delay neutrophil apoptosis primarily via stabilization of Mcl‐1.

Lymphocytic aleukemic leukemia cutis

A 21-year-old male patient had localized papules on the chest and arms. Biopsy of a lesion showed it to be a malignant lymphoid neoplasm, and immunohistochemical studies confirmed a lymphoblastoma origin. Aberrant lymphoid cells were noted in the cutaneous blood vessels, but simultaneous examination of the peripheral blood showed no evidence of leukemia. One month elapsed before observable leukemic cells were found in the blood and sternal marrow, confirming the diagnosis of acute lymphocytic leukemia. Examination of a cutaneous biopsy specimen led to early diagnosis of the disease.

Twenty-nail dystrophy (trachyonychia) caused by lichen planus in a patient with alopecia universalis and ichthyosis vulgaris

A 7-year-old girl with alopecia universalis had dystrophy of all 20 nails. A nail biopsy specimen disclosed features of lichen planus. The patient also had ichthyosis vulgaris and hypogammaglobulinemia. We are not aware of any previous reports of these associations, which we believe to be noncoincidental.

Activation of Human Neutrophils by Granulocyte Colony-Stimulating Factor, Granulocyte-Macrophage Colony-Stimulating Factor, and Tumor Necrosis Factor α: Role of Phosphatidylinositol 3-Kinase

Stimulation of human neutrophils with granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), or tumor necrosis factor a (TNF) resulted in phosphorylation of Akt, the potency being GM-CSF > G-CSF = TNF, which was inhibited by wortmannin. The findings indicated that phosphatidylinositol 3-kinase (PI3K) is activated by these cytokines. The possible participation of PI3K in activation of neutrophil functions induced by these cytokines was explored with PI3K inhibitors (wortmannin and LY294002). Superoxide release and adherence induced by GM-CSF or TNF were inhibited by PI3K inhibitors. Actin reorganization and morphological changes induced by G-CSF or GM-CSF were also inhibited by wortmannin, whereas these responses induced by TNF were unaffected by wortmannin. These findings suggested that PI3K is differentially involved in cytokine-mediated activation of neutrophil functions depending on the cytokines used. The results also showed that activation of extracellular signal-regulated kinase, but not p38 mitogen-activated protein kinase, induced by these cytokines is partly mediated by PI3K activation.

Squamous cell carcinoma of the scrotum

A patient with psoriasis was found to have a large skin tumor on his scrotum. He had received psoralen and ultraviolet A radiation therapy to control psoriasis. Histopathologic study revealed that the tumor was a well-differentiated squamous cell carcinoma. We present this rare case and suggest that the genitalia be shielded during ultraviolet therapy.