Homing, proliferation and survival sites of human leukemia cells in vivo in immunodeficient mice

The cellular components of the hematopoietic stem cell niche have been gradually identified. However, the niche for malignant hematopoiesis remains to be elucidated. Here, using human leukemia cells, which could be transplanted to immunodeficient mice, we studied the in vivo homing, proliferation and survival sites by immunohistopathology, compared with the corresponding sites for cord blood CD34(+) (CBCD34(+)) cells. The human leukemia cells initially localized on the surface of osteoblasts in the epiphysial region, and expanded to the inner vascular and diaphysial regions within 4 weeks. The percentage of CD34(+) leukemia cells in the bone marrow was transiently increased up to 50%. In vivo 5-bromo-2'-deoxyuridine labeling revealed that the epiphysis was the most active site for leukemia cell proliferation. CBCD34(+) cells showed the similar pattern of homing and proliferation to leukemia cells. After high-dose administration of cytosine-1-beta-D-arabinofuranoside, residual leukemia cells were localized in the perivascular endothelium as well as in contact with the trabecular endosteum. These findings suggest that xenotransplantation into immunodeficient mice provides a useful model to study the leukemia niche.

Mechanism of ASC-mediated apoptosis: bid-dependent apoptosis in type II cells

Apoptosis-associated speck-like protein containing a CARD (ASC) is an adaptor molecule that mediates apoptotic and inflammatory signals, and implicated in tumor suppression. However, the mechanism of ASC-mediated apoptosis has not been well elucidated. Here, we investigated the molecular mechanisms of ASC-mediated apoptosis in several cell lines using a caspase recruitment domain 12-Nod2 chimeric protein that transduces the signal from muramyl dipeptide into ASC-mediated apoptosis. Experiments using dominant-negative mutants, small-interfering RNAs and peptide inhibitors for caspases indicated that caspase-8 was generally required for ASC-mediated apoptosis, whereas a requirement for caspase-9 depended on the cell type. In addition, caspase-like apoptosis-regulatory protein (CLARP)/Fas-like inhibitor protein, a natural caspase-8 inhibitor, suppressed ASC-mediated apoptosis, and Clarp-/- mouse embryonic fibroblasts were highly sensitive to ASC-mediated apoptosis. Bax-deficient HCT116 cells were resistant to ASC-mediated apoptosis as reported previously, although we failed to observe colocalization of ASC and Bax in cells. Like Fas-ligand-induced apoptosis, the ASC-mediated apoptosis was inhibited by Bcl-2 and/or Bcl-XL in type-II but not type-I cell lines. Bid was cleaved upon ASC activation, and suppression of endogenous Bid expression using small-interfering RNAs in type-II cells reduced the ASC-mediated apoptosis. These results indicate that ASC, like death receptors, mediates two types of apoptosis depending on the cell type, in a manner involving caspase-8.

Cytokine production profile of splenocytes derived from zymosan A-treated SKG mice developing arthritis

OBJECTIVE

SKG mice have a point mutation of the zeta-associated protein of 70 kD (ZAP-70) and spontaneously develop a severe polyarthritis in the conventional condition, whereas they are healthy under the specific pathogen free (SPF) condition. The purpose of this study was to investigate the cytokine production from splenocytes in SKG mice developing arthritis under the SPF condition.

MATERIAL

SKG and BALB/c mice were intraperitoneally injected with zymosan A under the SPF condition. Spleen was isolated 1, 2 or 8 weeks after the intraperitoneal injection of saline or zymosan A. Splenocytes were cultured with concanavalin A. Cytokine production and proliferation were measured 48 and 72 h after the culture.

RESULTS

An intraperitoneal injection of zymosan A induced severe polyarthritis with increased levels of rheumatoid factor and interleukin 6 (IL-6) only in SKG mice. Splenocytes from SKG mice did not proliferate well maybe because of less productivity of IL-2. The IL-4 production from splenocytes of SKG mice was higher, while interferon-gamma production was lower than those of BALB/c mice. An injection of zymosan A reduced the IL-4 production only in SKG mice.

CONCLUSIONS

SKG mice do not develop arthritis under the SPF condition possibly because of a low proliferative activity of T cells and Th2-predominance.

Interstitial lung diseases associated with amyopathic dermatomyositis

The aim of the present study was to clarify the clinical characteristics and prognosis of patients with interstitial lung disease (ILD) associated with amyopathic dermatomyositis (ILD-ADM). The study consisted of 14 consecutive patients with ILD-ADM. Patients were classified into two categories, acute/subacute and chronic forms, according to the clinical presentation of ILD. The clinical features, responsiveness to therapy, and prognosis between the two forms were compared. Nine ILD-ADM patients were categorised as the acute/subacute form, and five as the chronic form. Arterial oxygen tension was significantly lower in the acute/subacute ILD than chronic ILD patients. On high-resolution computed tomography, ground-glass opacities were frequently found in the two forms, but consolidation was more common in acute/subacute ILD than chronic ILD. Bronchoalveolar lavage analysis showed higher numbers of total cells and lymphocytes in acute/subacute ILD than chronic ILD. Histologically, the most common finding was nonspecific interstitial pneumonia in the two forms, while diffuse alveolar damage was only found in acute/subacute ILD. Acute/subacute ILD was generally resistant to therapy, while chronic ILD responded well. Notably, the mortality of acute/subacute ILD was much higher than that of chronic ILD (67 versus 0%, respectively). In conclusion, interstitial lung disease associated with amyopathic dermatomyositis includes two different forms, the acute/subacute and chronic forms, with distinct prognoses.

Dietary fat and meat intake and idiopathic pulmonary fibrosis: a case-control study in Japan

SETTING

There is sparse epidemiologic information regarding the role of dietary factors in the development of idiopathic pulmonary fibrosis (IPF).

OBJECTIVE

To examine the relationship between specific types of fatty acids and selected foods high in fat and IPF in Japan.

DESIGN

Included were 104 cases aged > or = 40 years who had been diagnosed in the last 2 years in accordance with the most recent criteria. Controls aged > or = 40 years consisted of 56 hospitalised patients diagnosed as having acute bacterial pneumonia and four out-patients with common cold.

RESULTS

Intake of saturated fatty acids, mono-unsaturated fatty acids, n-6 polyunsaturated fatty acids and meat was independently associated with an increased risk of IPF. Specifically, the multivariate OR for comparison of the highest with the lowest quartile of intake of saturated fatty acids was 6.26 (95%CI 1.79-24.96, P for trend = 0.01) and for meat it was 7.19 (95%CI 2.15-27.07, P for trend = 0.02). Intake of cholesterol, n-3 polyunsaturated fatty acids, fish, eggs and dairy products was not related to the risk.

CONCLUSION

These findings suggest that consumption of saturated fatty acids and meat may increase the risk of IPF.

A novel mutation of the thiazide-sensitive sodium chloride cotransporter gene in a Japanese family with Gitelman syndrome

Gitelman syndrome is an inherited renal disorder characterized by impaired NaCl reabsorption in the distal convoluted tubule leading to hypokalemia, hypomagnesemia and normocalcemic hypocalciuria. It has been shown that this syndrome results from mutations in the gene encoding the thiazide-sensitive sodium chloride cotransporter (TSC). We performed the mutational analysis in the TSC gene of a 30-year-old Japanese woman with Gitelman syndrome and found two mutations at adjacent spots in both alleles. One was a frame shift mutation which generated stop codon at position 671, the other was a single nucleotide mutation, which resulted in an aminoacid substitution at position 672, Met to Ile. Her 52-year-old mother and two daughters had neither hypokalemia nor hypomagnesemia. However, her mother and her 8-year-old daughter had the Met672Ile mutation as heterozygotes. Her 4-year-old daughter had the same frame shift mutation as her mother, a heterozygotic mutation. These results suggest that Gitelman syndrome requires 2 compound heterozygotic mutations and the coexistence of the large deletion in the C-terminal domain with Met672Ile substitution of the TSC could impair the transporter activity underling the hypokalemia and hypomagnesemia in this patient.

Diagnosis of a case of Gitelman's syndrome based on renal clearance studies and gene analysis of a novel mutation of the thiazide-sensitive Na-Cl cotransporter

Gitelman's syndrome is a recessively inherited renal tubular disorder characterized by low plasma potassium and magnesium levels, reduced calcium excretion, metabolic alkalosis, and increased plasma renin activity and plasma aldosterone concentration with normal blood pressure levels. A 23-yr-old man was referred to our department for further evaluation of hypokalemia. The patient also had hypomagnesemia and markedly reduced urinary calcium excretion. Renal clearance studies and gene analysis of the thiazide-sensitive Na-Cl cotransporter (TSC) were performed in the patient. In response to an iv injection of furosemide, chloride clearance (CCl) increased markedly, while distal fractional chloride reabsorption CH2O/(CH2O+CCl) was considerably reduced. In contrast, thiazide ingestion had no significant effects on these parameters. The patient had compound heterozygous mutations in the alleles encoding the TSC gene, one of which has not been formerly reported. Renal clearance studies and TSC gene analysis by amplification and direct sequencing are useful diagnostic tools for confirming a diagnosis of Gitelman's syndrome.

Clinical significance of Ki-67 proliferation index in disease progression and prognosis of patients with resected colorectal carcinoma

BACKGROUND

The prognostic role of proliferation markers in patients with colorectal neoplasia is inconclusive. The aim of this study was to evaluate proliferation markers in patients with colorectal carcinoma, to relate these to standard clinicopathological findings and to investigate their potential role in the prediction of long-term survival.

METHODS

Archived formalin-fixed, paraffin-embedded tissue samples from a cohort of 106 patients who underwent curative resection for colorectal carcinoma were analysed to determine a Ki-67 (MIB-1)-derived proliferation index (PI) using a double immunostaining technique. The relationship between PI and standard clinicopathological variables was assessed and its association with long-term survival evaluated.

RESULTS

A significant association was found between PI and tumour (T) status (P = 0.001), lymph node (N) involvement (P = 0.0098), the presence of distant metastases (P < 0.010) and advanced stage of disease (P < 0.001). On multivariate analysis, PI was shown to be an independent prognostic factor for long-term survival (hazard ratio 2.1 (95 per cent confidence interval 1.1 to 4.1); P = 0.032).

CONCLUSION

Cell proliferation is significantly associated with tumour progression and may be used to identify patients with a predicted adverse outcome after resection of colorectal carcinoma.

Dapsone suppresses human neutrophil superoxide production and elastase release in a calcium-dependent manner

BACKGROUND

Dapsone (4,4'-diaminodiphenyl sulphone) is a powerful therapeutic tool in many skin diseases including neutrophilic dermatoses. The drug has an outstanding therapeutic efficacy against many skin diseases characterized by neutrophil-rich infiltrates; however, mechanisms of its action are poorly understood.

OBJECTIVES

We investigated the effects of dapsone on respiratory and secretory functions of human neutrophils triggered by the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP), the physiological agonist C5a, and phorbol myristate acetate (PMA).

METHODS

Human neutrophils were isolated from venous blood obtained from healthy donors. We detected extracellular production of superoxide (O(2) (-)) by cytochrome C reduction assay, and intracellular production of O(2) (-) by flow cytometry. Neutrophil elastase release was measured by the cleavage of the specific elastase substrate N-methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroanilide. Measurement of cytosolic free calcium concentration was performed using the calcium-reactive fluorescence probe, Fluo-3.

RESULTS

Dapsone suppressed intra- and extracellular production of O(2) (-) and elastase release triggered by fMLP and C5a, but not by PMA. Both fMLP and C5a signalled the above pathways by inducing calcium influx, but PMA functions bypassed calcium influx. Dapsone was capable of antagonizing the induction of calcium influx.

CONCLUSIONS

These findings suggest that one mechanism of the anti-inflammatory action of dapsone is inhibition of calcium-dependent functions of neutrophils including release of tissue-damaging oxidants and proteases in the affected skin.

Absence of regulatory effects of 1alpha25-dihydroxyvitamin D3 on 25-hydroxyvitamin D metabolism in rats constantly infused with parathyroid hormone

The regulatory role of 1alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2-D3] in metabolism of 25-hydroxyvitamin D was studied in sham-operated (sham) or thyroparathyroidectomized (TPTX) vitamin D-deficient rats into which calcium and parathyroid hormone (PTH) were constantly infused. A single dose of 325 or 650 pmol of 1alpha,25-(OH)2-D3 caused significant inhibition of 1alpha,25-(OH)2-D3 synthesis in D-deficient sham rats. This inhibition by 1alpha,25-(OH)2-D3, however, was not observed in D-deficient TPTX rats into which PTH was constantly infused. These results can be explained by supposing that the major regulatory effect of 1alpha,25-(OH) 2-D3 on 1alpha,25-(OH)2-D3 synthesis is realized mostly, if not all, by suppressing endogenous secretion of PTH.

Influence of apolipoprotein E genotype on the response to caloric restriction in type 2 diabetic patients with hyperlipidaemia

AIMS

Hyperlipidaemia is a major predisposing factor to atherosclerosis in patients with type 2 diabetes. Apolipoprotein (apo) E polymorphism influences lipoprotein metabolism, and the present study was undertaken to explore the relation, in type 2 diabetics, between apo E genotype and the plasma lipid response to dietary therapy.

METHODS

The subjects were 104 patients with type 2 diabetes and hyperlipidaemia, and the difference, due to apo E genotype, in dietary response was followed for 4-6 weeks. The caloric intake was maintained in the range 20-25 kcal/kg, and the medications for diabetes were not changed during the follow-up period.

RESULTS

Plasma total cholesterol (TC) and triglyceride (TG) levels were significantly lowered by the dietary treatment in patients with apo E genotypes of epsilon3/3, epsilon2/3 and epsilon3/4; however, the lipid levels in patients with epsilon2/4 did not respond to the diet.

CONCLUSIONS

apo E genotype should be taken into consideration in the treatment of hyperlipidaemia in diabetic patients.

S 12911-2 inhibits osteoclastic bone resorption in vitro

The potential anti-osteoporotic activity of the strontium compound, S12911, was tested on osteoclast-like cells and on cultured fetal mouse long bones. From 1 mM Sr2+, S12911 reduced both basal and stimulated bone resorption by decreasing osteoclast activity and ruffled border formation. The aim of this study was to evaluate the effects of S 12911-2 on osteoclastic bone resorption using in vitro systems. Osteoclast-like cells, produced in vitro by co-culture of mouse bone marrow cells with primary osteoblasts, were allowed to settle on dentine slices, and the area of resorption pits formed after 48 h was measured using an image analysis system. S 12911-2, at a minimal active concentration of 1 mM Sr2+, significantly reduced pit formation by these cells (p < 0.05). Pretreatment of slices for 48 h with S 12911-2 (5 mM Sr2+) did not produce appreciable inhibition of resorption. Bone resorption in cultured fetal mouse long bones was assessed by measuring the release of pre-incorporated 45calcium. S 12911-2 inhibited resorption in control cultures (18.9%, p < or = 0.05) and in bones cultured with the active form of vitamin D3 [1,25(OH)2D3] (44.5%, p < or = 0.05). S 12911-2 had no effect on the number of osteoclasts observed histochemically in longitudinal sections prepared from fetal mouse long bones. Electron microscopy of mouse long bones treated with S 12911-2 (3 mM Sr2+) showed osteoclasts with clear zones facing the bone surface, but without well-developed ruffled borders; untreated bones contained osteoclasts with normal ruffled borders. These results indicate that S 12911-2 inhibits osteoclast activity. This effect is directly linked to the presence of strontium, is effective on basal and stimulated resorption, and involves a decrease in ruffled border formation by osteoclasts.

Genomic structure and inducible expression of the IL-22 receptor alpha chain in mice

IL-22 is a newly identified member of the interferon/IL-10 family. In humans, IL-22 signals through a heteroduplex receptor consisting of IL-22R and CRF2-4/IL-10Rbeta. To investigate the physiological function of IL-22 and IL-22R, we isolated a cDNA encoding the mouse IL-22R, which has been a missing component of the functional receptor complex for mouse IL-22. Subsequently, we identified the genomic sequence of the mouse IL-22R gene by a database search. The gene consists of about 24 kb and is split into seven exons. Interestingly, intron 2 begins with a GC dinucleotide instead of the consensus GT, although otherwise the overall structure of the mouse IL-22R gene is strikingly similar to its human counterpart. The gene was mapped to mouse chromosome 4 in the region syntenic to the human IL-22R gene locus. In normal mice, IL-22R mRNA is detected at very low levels in restricted organs such as the kidney, liver, and lung. However, upon lipopolysaccharide stimulation, IL-22R mRNA expression is highly upregulated in the liver, in contrast to CRF2-4, which is expressed constitutively in a variety of tissues. Thus, the expression of the functional IL-22 receptor in the liver is regulated at the gene transcription level.

Lack of evidence for a role of Epstein-Barr virus in the increase of lung cancer in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is known as an independent risk factor for lung cancer. Because Epstein-Barr virus (EBV) may be involved in the genesis of IPF as well as certain malignancies, we investigated whether EBV contributes to the increased incidence of lung cancer in IPF The formalin-fixed and paraffin-embedded lung sections were prepared from 22 lung cancer patients with IPF and 22 lung cancer patients without IPF All ofthe IPF patients pathologically showed usual interstitial pneumonia. In situ hybridization for EBV-encoded small non-polyadenylated RNAs failed to show positive signals in the cancer tissues of either IPF or non-IPF patients. This study did not provide evidence for an etiologic role of EBV in the development of lung cancer in IPF.

Th1/Th2 profile in peripheral blood in atopic cough and atopic asthma

BACKGROUND

Eosinophilic tracheobronchitis with cough hypersensitivity, abbreviated as atopic cough, is an important cause of chronic cough. The reason for the absence of airway hyper-responsiveness is unknown, differing from asthma, a Th2 cytokine-mediated disorder.

OBJECTIVE

To compare the type 1 helper T cell (Th1)/Th2 balance in the peripheral blood from subjects with atopic cough and atopic asthma, we assessed the intracellular cytokine production at the single-cell level.

METHODS

Thirty-six subjects (10 patients with atopic cough, 18 with atopic asthma, and eight control subjects) were included. Intracellular IL-4 and IFN-gamma were detected in CD4+ T cells by flow cytometry.

RESULTS

A significantly lower ratio of IFN-gamma-/IL-4-producing CD4+ T cells after phorbol 12-myristate acetate/ionomycin stimulation was found in patients with atopic cough and atopic asthma compared with normal subjects. In comparison between atopic patients, the ratio of IFN-gamma-/IL-4-producing cells was significantly higher in atopic cough than in atopic asthma. However, the proportion of IL-4-producing CD4+ T cells was significantly higher in patients with atopic asthma than in normal control subjects and no significant difference was detected between patients with atopic cough and normal subjects. No significant difference in the proportion of IFN-gamma-producing cells was found between the subjects. Overall, the total IgE levels were positively correlated to the IL-4-producing cells and inversely correlated to the ratio of IFN-gamma-/IL-4-producing cells.

CONCLUSION

These results show the lower degree of Th2 cytokine predominance in atopic cough compared with atopic asthma and suggest the relation between the Th1/Th2 balance and atopic status.