Estrogen prevents oxidative stress-induced endothelial cell apoptosis in rats

BACKGROUND

Estrogen replacement attenuates the increased risk of cardiovascular disease in postmenopausal women. Recent studies using an in vitro culture system have shown that estrogen inhibits endothelial cell (EC) apoptosis. The in vivo relevance of this finding, however, is not defined. To do so, we have developed a rat vascular injury model in which EC apoptosis induced by hydrogen peroxide plays a role.

METHODS AND RESULTS

Intracarotid arterial administration of 0.01 mmol/L hydrogen peroxide for 5 minutes evoked EC apoptosis after 6 to 24 hours, determined by nuclear staining with Hoechst 33342, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, and electron microscopy. Apoptosis was associated with EC loss and was followed by EC regeneration at 72 hours and neointima formation at 1 to 2 weeks. Estradiol replacement in ovariectomized female Wistar rats decreased the rate of apoptotic ECs by approximately 50%, assayed by nuclear morphology of en face specimens, resulting in increased remaining ECs and decreased neointima formation. Progesterone did not influence the effects of estradiol on EC apoptosis.

CONCLUSIONS

These results provide new insight into the cardioprotective action of estrogen as well as a paradigm of the response-to-injury hypothesis.

Effect of IL-12 encoding plasmid administration on tight-skin mouse

The tight-skin (Tsk/+) mutant mice, a putative murine model of scleroderma, are characterized by the excessive deposition of collagen and the presence of antinuclear antibodies. Type 2 cytokines, such as IL-4 and IL-6, are capable of regulating the synthesis of various matrix molecules, including type I collagen, by fibroblasts. IL-12 is well known to induce type 1 cytokine production and to reduce type 2 activity. Here, we examined the effect of IL-12 encoding plasmid (pCAGGSIL-12) on the disease progression of Tsk/+ mice. pCAGGSIL-12 plasmid or pCAGGS parental vector was injected intramuscularly 7 times at 3 week intervals into Tsk/+ mice. One week after the last injection, pCAGGSIL-12 administered Tsk/+ mice exhibited a marked decrease in the skin thickness compared with the mice treated with pCAGGS vector. The serum levels of antinuclear antibodies were diminished in pCAGGSIL-12 treated mice. IL-4 production by spleen cells from pCAGGSIL-12 plasmid treated mice was significantly lower than that from vector treated mice. These results indicate that pCAGGSIL-12 administration into Tsk/+ mice had beneficial effects in preventing the collagen accumulation in the skin and suppressing the autoimmunity via improvement of Th1/Th2 balance. The present study suggests that the IL-12 encoding plasmid administration might have a therapeutic effect on systemic sclerosis.

A high serum-soluble interleukin-2 receptor level is associated with a poor outcome of aggressive non-Hodgkin's lymphoma

Soluble interleukin-2 receptor (sIL-2R) is produced by activated T and B cells, and the level of this receptor is elevated in patients with non-Hodgkin's lymphoma (NHL). The present study demonstrated that the sIL-2R level was high in the following groups of patients with aggressive NHL; those aged > or = 60 yr, those with a poor PS, those in Ann Arbor stage III or IV, and those in the high intermediate or high risk group according to the International Prognostic Index (IPI). Overall survival was significantly poorer when the sIL-2R level was 2000 U/ml or more. In addition, the overall survival of patients in the low (L) and low-intermediate (L-I) risk groups with an sIL-2R level of 3000 U/ml or more was significantly poorer, suggesting that the sIL-2R level could be particularly useful for identifying patients with a poor prognosis among the L and L-I risk groups. Univariate analysis identified some significant prognostic factors, and multivariate analysis of these factors plus the five IPI prognostic factors showed that the sIL-2R level was an independent prognostic indicator. In conclusion, the present findings established that the sIL-2R level is a significant independent prognostic factor in patients with aggressive NHL.

A factor XI deficiency associated with a nonsense mutation (Trp501stop) in the catalytic domain

We identified a novel mutation in an asymptomatic 65-year-old Japanese man with severe factor XI deficiency. Sequence analysis after polymerase chain reaction single-stranded conformation polymorphism (PCR-SSCP) analysis of his factor XI gene revealed a G-->A transition in codon 501 of exon 13, resulting in a substitution of Trp501 (TGG) by a stop codon (TAG) in the catalytic domain. This mutation abolished a FokI restriction site. The PCR product from normal subjects was digested with FokI and yielded two fragments, one of 223 bp and one of 47 bp. The PCR product from the patient gave a single 270-bp fragment, demonstrating possible homozygosity.

Pericardial constriction due to malignant lymphoma

We experienced a case of T-cell lymphoma demonstrating diastolic heart failure as an initial manifestation. An 81-year-old Japanese male was admitted to the University of Tokyo Hospital because of progressive dyspnea and general fatigue. Clinical presentation was congestive heart failure and cervical lymphadenopathy. Right heart catheterization revealed "dip and plateau" waveforms in right ventricular pressure, which suggested a constrictive nature of heart failure. Gallium scintigram showed marked uptake in the heart. Biopsy from a cervical lymph node confirmed the diagnosis of malignant lymphoma of T-cell origin. Diastolic heart failure remained after successful chemotherapy. Autopsy revealed pericarditis with severe adhesion of the pericardium and the epicardium.

Neuron-specific phosphorylation of Alzheimer's beta-amyloid precursor protein by cyclin-dependent kinase 5

The mature form of Alzheimer's beta-amyloid precursor protein (APP) is phosphorylated specifically at Thr(668) in neurons. In mature neurons, phosphorylated APP is detected in neurites, with dephosphorylated APP being found mostly in the cell body. In vitro, active cyclin-dependent kinase 5 (Cdk5) phosphorylated the cytoplasmic domain of APP at Thr(668). Treatment of mature neurons with an antisense oligonucleotide to Cdk5 suppressed Cdk5 expression and significantly diminished the level of phosphorylated APP. The expression of APP was unaffected in antisense-treated neurons. These results indicate that in neurons APP is phosphorylated by Cdk5, and that this may play a role in its localization.

Expression of thrombopoietin receptor and its functional role in human B-precursor leukemia cells with 11q23 translocation or Philadelphia chromosome

Thrombopoietin (TPO) is a hematopoietic growth factor which plays a central role in normal megakaryocytopoiesis and thrombopoiesis. Although the interaction between TPO and its receptor c-Mpl encoded by the c-mpl gene is now known to be implicated in the proliferation and/or differentiation of abnormal myeloid cells and normal hematopoietic stem cells, little is known about a role of the TPO/c-Mpl system in lymphoid leukemia cells. In the present study, we first examined the expression of c-mpl/c-Mpl in 23 human lymphoid leukemic cell lines (T-lineage 4, B-lineage 19) using three distinct methods. The c-mpl mRNA was detectable in as many as 20 cell lines (T-lineage 3, B-lineage 17) by reverse transcriptase-polymerase chain reaction, but its translated product, c-Mpl, was demonstrable by Western blot only in B-lineage cell lines. Flow cytometric analysis revealed the surface c-Mpl expression in 13 of 17 B-lineage cell lines, but its higher expression (>40%) was restricted in nine B-precursor cell lines, eight of which had 11q23 translocation or Philadelphia chromosome (Ph1). We also demonstrated that two of eight cell lines with 11q23 translocation or Ph1 exhibited a significant proliferative response to TPO in the 3H-thymidine uptake and colony-forming assays. Triggering of these cell lines by TPO transiently up-regulated tyrosine phosphorylation of JAK-2 and Shc, indicating that their receptor is functional. Primary leukemia cells separated from patients with B-precursor acute lymphoblastic leukemia with Ph1 or 11q23 translocation also showed the surface c-Mpl expression and a significant responsiveness to TPO. These results suggest that the TPO/c-Mpl interaction may play a physiological role in the growth regulation of B-precursor leukemia cells particularly with specific chromosomal abnormalities.

Participation of granulocyte colony-stimulating factor in the growth regulation of leukemia cells from Philadelphia chromosome-positive acute leukemia and blast crisis of chronic myeloid leukemia

Granulocyte colony-stimulating factor (G-CSF) has been shown to support the growth of multipotential hematopoietic stem cells in addition to the cells of neutrophilic lineage. Philadelphia chromosome (Ph1)-positive leukemia has its origin in the hematopoietic stem cell. In the present study, we demonstrated that the proliferation of leukemic cells from chronic myeloid leukemia in blast crisis (CML-BC) and Ph1-positive acute lymphoblastic leukemia (ALL) cases is frequently stimulated with G-CSF in vitro. We next studied a total of 12 leukemic cell lines established from CML-BC (n= 6) and Ph1-positive acute leukemia (n= 6): four 'myeloid', five 'biphenotypic', and three 'lymphoid' types. All cell lines expressed G-CSF receptor (G-CSFR) in flow cytometric analysis, but their proliferative response to G-CSF in 3H-thymidine incorporation assay varied. The 'biphenotypic' cell lines expressed G-CSFR at higher levels and showed the most pronounced response to G-CSF. The 'lymphoid' cell lines showed intermediate G-CSFR expression with the modest response to G-CSF. Unexpectedly, 'myeloid' cell lines showed lower G-CSFR expression and lower G-CSF response compared with 'biphenotypic' cell lines. In three of four 'myeloid' cell lines, proliferation was partially inhibited by an addition of anti-G-CSF neutralizing monoclonal antibody into culture medium. Further, the % inhibition of 3H-thymidine uptake of cell lines positively correlated with the amount of their intracellular G-CSF measured by enzyme immunoassay, suggesting an autocrine growth mechanism via the G-CSF/G-CSFR interaction. These results suggest that G-CSF play an important role in the growth regulation of leukemia cells from Ph1-positive acute leukemia and CML-BC.

Analysis of serum lactate dehydrogenase and its isozymes during administration of granulocyte colony-stimulating factor in children

Serum lactate dehydrogenase (LDH) activity is known to become elevated following granulocyte colony-stimulating factor (G-CSF) therapy in some patients, but no extensive studies on this phenomenon have been performed. In 26 children with malignancies in complete remission who received recombinant human G-CSF intravenously after combined chemotherapy, we measured serum LDH and its isozymes (81 episodes) before chemotherapy (pre-Tx), during administration of G-CSF (mid-Tx), and after stopping G-CSF (post-Tx) and compared the obtained data using paired t test. Twelve episodes were excluded from analysis because of liver dysfunction (alanine aminotransferase > 45 IU/L). Serum LDH at mid-Tx (343.1+/-19.8 IU/L; mean +/- SE) was significantly higher than that at pre-Tx (186.9+/-6.7 IU/L) and post-Tx, but this difference was observed only when change in white blood cell counts (WBCs) (WBC at mid-Tx minus WBC at pre-Tx) was greater than or equal to 4000/microL (58 episodes). Percentages of LDH isozymes 3, 4, and 5 at mid-Tx (23.5+/-1.0, 11.7+/-0.8, and 8.3+/-0.7) were significantly increased compared with those at pre-Tx (19.5+/-0.7, 6.3+/-0.3, and 4.2+/-0.5) and post-Tx, resulting in a significant decrease in percentages of LDH isozymes 1 and 2 at mid-Tx. In episodes of change in WBCs > or =4000/microL, change in LDH significantly correlated to changes in WBCs and granulocytes but not to change in lymphocytes or monocytes. These results suggest that serum LDH is significantly elevated during G-CSF administration in accordance with the increase in peripheral granulocytes, which accompanies change in the pattern of percentages of LDH isozymes.

Antitumor activity of astaxanthin and its mode of action

Astaxanthin, a carotenoid without vitamin A activity, may exert antitumor activity through the enhancement of immune responses. Here, we determined the effects of dietary astaxanthin on tumor growth and tumor immunity against transplantable methylcholanthrene-induced fibrosarcoma (Meth-A tumor) cells. These tumor cells express a tumor antigen that induces T cell-mediated immune responses in syngenic mice. BALB/c mice were fed astaxanthin (0.02%, 40 micrograms/kg body wt/day in a beadlet form) mixed in a chemically defined diet starting zero, one, and three weeks before subcutaneous inoculation with tumor cells (3 x 10(5) cells, 2 times the minimal tumorigenic dose). Three weeks after inoculation, tumor size and weight were determined. We also determined cytotoxic T lymphocyte (CTL) activity and interferon-gamma (IFN-gamma) production by tumor-draining lymph node (TDLN) and spleen cells by restimulating cells with Meth-A tumor cells in culture. The astaxanthin-fed mice had significantly lower tumor size and weight than controls when supplementation was started one and three weeks before tumor inoculation. This antitumor activity was paralleled with higher CTL activity and IFN-gamma production by TDLN and spleen cells in the astaxanthin-fed mice. CTL activity by TDLN cells was highest in mice fed astaxanthin for three weeks before inoculation. When the astaxanthin-supplemented diet was started at the same time as tumor inoculation, none of these parameters were altered by dietary astaxanthin, except IFN-gamma production by spleen cells. Total serum astaxanthin concentrations were approximately 1.2 mumol/l when mice were fed astaxanthin (0.02%) for four weeks and appeared to increase in correlation with the length of astaxanthin supplementation. Our results indicate that dietary astaxanthin suppressed Meth-A tumor cell growth and stimulated immunity against Meth-A tumor antigen.

Haemophilus parainfluenzae antigen and antibody in children with IgA nephropathy and Henoch-Schönlein nephritis

Although the pathogenesis of immunoglobulin A (IgA) nephropathy and Henoch-Schönlein nephritis (HSN) remains uncertain, there is substantial evidence that they are immune complex-mediated diseases. Recently, Haemophilus parainfluenzae antigens were shown in the glomerular mesangium of adult patients with IgA nephropathy, and greater levels of IgA antibody against H parainfluenzae were also shown in the sera of adult patients with IgA nephropathy. The present study was performed to detect H parainfluenzae antigens and antibody against H parainfluenzae in children with IgA nephropathy and HSN. H parainfluenzae antigens in the mesangium were examined by indirect immunofluorescence, and antibody against H parainfluenzae was examined by enzyme-linked immunosorbent assay. Diffuse global staining of the mesangium with rabbit antisera against H parainfluenzae was shown in 10 of the 32 patients (31%) with IgA nephropathy and 12 of the 34 patients (35%) with HSN. Conversely, only 2 of the 47 patients (4%) with other renal diseases showed staining of glomeruli with rabbit antisera against H parainfluenzae (IgA nephropathy versus other renal diseases, P = 0.003; HSN versus other renal diseases, P = 0.0006). Patients with IgA nephropathy and those with HSN showed significantly greater levels of plasma IgA1 antibody against H parainfluenzae than patients with other renal diseases (IgA nephropathy versus other renal diseases, P = 0.008; HSN versus other renal diseases, P = 0.025). These findings suggest that H parainfluenzae has a role in the cause of these two conditions in a subset of patients.

Effects of Kampo medicine, Toki-shakuyaku-san (Tang-Kuei-Shao-Yao-San), on choline acetyltransferase activity and norepinephrine contents in brain regions, and mitogenic activity of splenic lymphocytes in ovariectomized mice

We investigated the effects of Toki-shakuyaku-san (TSS, Tang-Kuei-Shao-Yao-San in Chinese), Japanese traditional herbal medicine, on the nervous and immune systems in ovariectomized mice as a climacteric disorder model. Female C57BL/6 mice were ovariectomized (OVX) and TSS was given daily through the drinking water for either 10 or 20 days from the day after ovariectomy. After completion of experimental sessions, animals were sacrificed and specific brain regions were assayed for choline acetyltransferase (ChAT) activity and norepinephrine contents. The mitogenic activities, alkaline phosphatase activity and 3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H terazolium bromide (MTT) activity, in splenic lymphocytes has also measured. Furthermore, the effects of TSS on learning and memory ability were studied by the step-through type passive avoidance test. As the results, the administration of TSS significantly suppressed the decrease of ChAT activity in the cerebral cortex (CC) and the dorsal hippocampus (DH) of ovariectomized mice at 10 days after ovariectomy, however no significant effect was observed at 20 days after ovariectomy. Norepinephrine contents in OVX group were decreased at 10 and 20 days after ovariectomy in the CC and the ventral hippocampus (VH). The administration of TSS significantly suppressed the decrease of norepinephrine contents at 20 days after ovariectomy. The mitogenic activities of lymphocyte in spleen were increased at 10 days after ovariectomy, and decreased at 20 days after ovariectomy. However, the suppression of these changes was observed in the group given TSS. The mean latent period was also shortened in the passive avoidance test in the OVX group, but TSS treated group improved mean latency. From these observations, it is inferred that administration of TSS brings on the synthesis of acetylcholine and norepinephrine in the CC and hippocampus, and may improve the memory related behavior and the abnormalities in lymphocytes in the models of the climacteric disorder.

Platelet-activating factor acetylhydrolase gene mutation in Japanese children with Escherichia coli O157-associated hemolytic uremic syndrome

Platelet-activating factor (PAF) may be involved in the pathogenesis of Escherichia coli O157-associated hemolytic uremic syndrome (HUS). PAF is degraded to inactive products by PAF acetylhydrolase. In this study, we investigated whether a PAF acetylhydrolase gene mutation (G-->T transversion at position 994) is involved in HUS in Japanese children. A point mutation in the PAF acetylhydrolase gene (G994T) was identified using polymerase chain reaction in 50 Japanese children with E coli O157-associated HUS and 100 healthy Japanese. We then determined the relationship between the PAF acetylhydrolase G994T gene mutation and clinical features of HUS. There was no difference in genotype and allele frequencies between patients with HUS and healthy controls. The mean duration of oligoanuria was significantly longer in patients with the GT genotype than in those with the GG genotype (P = 0.012). Although 11 of 15 patients (73%) heterozygous for the mutant allele (GT) required dialysis, only 13 of the 35 wild-type homozygotes (GG; 37%) required dialysis (P = 0. 030). Mean plasma PAF acetylhydrolase activity was significantly less in patients with the GT genotype than in those with the GG genotype (P < 0.0001). In conclusion, we have shown an association between the G994T PAF acetylhydrolase gene mutation and the severity of renal damage in E coli O157-associated HUS. Our study suggests that analysis of the PAF acetylhydrolase gene mutation in Japanese children with E coli O157-associated HUS may allow the prediction of the severity of HUS.

Primary squamous cell carcinoma of the breast during lactation: a case report

A case of primary squamous cell carcinoma of the breast during lactation is reported. The patient was a 32-year-old woman, in post-partum lactating 18 months after delivery, who was referred to our hospital following detection of a lump in her left breast during physical examination in mass screening for breast cancer. The tumor, palpated in the upper outer quadrant of the left breast, was firm, well-defined and 2.8 x 2.6 cm in size. Ultrasonograms identified an irregular-shaped hypoechoic lesion and mammograms revealed a well-defined, circumscribed tumor. Based on these findings, breast cancer was suspected and an excisional biopsy was performed. The resected specimen was a firm, solid and circumscribed tumor with central hemorrhage. Microscopic findings demonstrated that the tumor consisted of an invasive ductal carcinoma with marked squamous metaplasia, such as keratinization and squamo-columnar junction. Breast-conserving surgery was performed and no lymph node involvement was noted. Both estrogen and progesterone receptors of the tumor were negative. Generally, the size of both squamous cell carcinoma and carcinoma during the lactation period tends to be larger than ordinary carcinomas. In this case, the cancerous lesion was detected at a relatively early stage. Although the cancerous lesion was detected at a relatively early stage and no lymph node involvement was noted, lung metastases occurred within 12 months of the surgery. Malignant potential is generally considered to be high in cases of squamous cell carcinoma of the breast with lactation and thus intensive treatment potentially resulting in severe side effects was considered to be necessary for this patient.

Genetics of immunoglobulin A nephropathy

INTRODUCTION

Immunoglobulin (Ig) A nephropathy is the most common primary glomerulonephritis in the world and about 20% to 50% of patients with it develop progressive renal failure. There is considerable evidence to show that IgA nephropathy is influenced by genetic factors. The purpose of this review is to provide useful information concerning genetics of IgA nephropathy.

METHODS AND RESULTS

Epidemiological, familial clustering, human leukocyte antigen and IgA immune system (immunoglobulin class switch gene, I alpha 1 germ-line transcript regulatory region gene) studies have led to the hypothesis of genetic susceptibility to IgA nephropathy. Moreover, research on renin angiotensin system, platelet activating factor acetylhydrolase, neuropeptide Y Y1 receptor and others genes has demonstrated that genetic factors influence the pathological severity and natural course of IgA nephropathy.

CONCLUSIONS

The evidence presented in this review strongly supports the role of genetic factors in IgA nephropathy. Detection of genetic risk factors for IgA nephropathy will allow us to study further the pathogenesis of IgA nephropathy and devise effective therapy.

Hepatoprotective effects of Inula britannica on hepatic injury in mice

Inula britannica, a Kampo medicine, is prepared from the heads of Compositae plants such as Inula britannica L., which has been used clinically as a remedy for nausea, hiccup and excessive sputum. Here it is shown that administration of Inula britannica improves the survival rate of mice with hepatic injury induced by LPS/PA. It is also suggested that administration of Inula britannica significantly reduces the fluctuation in the amount of cytokine in the spleen of mice with hepatic injuries, and that the Th1/Th2 control effect is related to the inhibitory action of Inula britannica against hepatic injury. In vitro testing suggests that Inula britannica suppresses Th1 differentiation and induces Th2 differentiation by inhibiting the production of macrophage IL-12 and promoting the production of IL-10, thus showing the immunological effect of hepatic injury inhibition by affecting the balance between Th1 and Th2.

Association of coronary risk factors and endothelium-dependent flow-mediated dilatation of the brachial artery

Impaired endothelial function has been reported to be the initial step in atherosclerosis. Some coronary risk factors independently relate to impaired endothelial function. However, few studies have examined the association between coronary risk factors and endothelial function in patients who have multiple risk factors without clinical atherosclerosis. This study was undertaken to elucidate the relationship between accumulation of coronary risk factors and vascular endothelial dysfunction. We examined 101 subjects with one or more coronary risk factors 56.8 +/- 1.0 years old and 40 age-matched control subjects without coronary risk factors. We measured brachial artery diameter non-invasively using a 7.5-MHz ultrasound machine at rest, during reactive hyperemia caused by endothelium-dependent vasodilatation, and after sublingual administration of nitroglycerin, which causes endothelium-independent vasodilatation. The percentage change in flow-mediated diameter (%FMD; deltaD/D x 100), in subjects with one or more coronary risk factors was significantly lower than that in control subjects(4.8 +/- 0.3% vs. 6.7 +/- 0.5%, p < 0.01). Endothelium-independent vasodilatation by nitroglycerin did not differ between the two groups. Endothelial function was impaired according to the accumulation of coronary risk factors. On multiple regression analysis, the number of risk factors, age, and brachial artery diameter at rest showed significant correlation with %FMD. Our results suggest that an accumulation of coronary risk factors was significantly related to impairment of endothelial function.