Sirt1 inhibitor, Sirtinol, induces senescence-like growth arrest with attenuated Ras-MAPK signaling in human cancer cells

The induction of senescence-like growth arrest has emerged as a putative contributor to the anticancer effects of chemotherapeutic agents. Clinical trials are underway to evaluate the efficacy of inhibitors for class I and II histone deacetylases to treat malignancies. However, a potential antiproliferative effect of inhibitor for Sirt1, which is an NAD(+)-dependent deacetylase and belongs to class III histone deacetylases, has not yet been explored. Here, we show that Sirt1 inhibitor, Sirtinol, induced senescence-like growth arrest characterized by induction of senescence-associated beta-galactosidase activity and increased expression of plasminogen activator inhibitor 1 in human breast cancer MCF-7 cells and lung cancer H1299 cells. Sirtinol-induced senescence-like growth arrest was accompanied by impaired activation of mitogen-activated protein kinase (MAPK) pathways, namely, extracellular-regulated protein kinase, c-jun N-terminal kinase and p38 MAPK, in response to epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I). Active Ras was reduced in Sirtinol-treated senescent cells compared with untreated cells. However, tyrosine phosphorylation of the receptors for EGF and IGF-I and Akt/PKB activation were unaltered by Sirtinol treatment. These results suggest that inhibitors for Sirt1 may have anticancer potential, and that impaired activation of Ras-MAPK pathway might take part in a senescence-like growth arrest program induced by Sirtinol.

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.

Fumonisins as a possible contributory risk factor for primary liver cancer: a 3-year study of corn harvested in Haimen, China, by HPLC and ELISA

Employing HPLC fluorometry, gas-liquid chromatography (GLC) and a novel enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody, 40 corn samples, each collected in 1993 from agricultural stocks for human consumption in Haimen (Jiangsu County) and Penlai (Shandong Province), high- and low-risk areas for primary liver cancer (PLC) in China, respectively, were analysed for fumonisins (FBs), aflatoxins (AFs) and trichothecenes. Levels and positive rates of FBs and deoxynivalenol (DON) were significantly higher in Haimen than in Penlai. ELISA of the 40 corn samples harvested in the two areas in 1994 revealed that FB contamination levels and rates in these areas were comparable to those observed in 1993 in Haimen. ELISA analysis of 1993 and 1994 products revealed a wide occurrence of AFB1 but the positive rates as well as levels were not significantly different between these areas. ELISA of the same sample number of corn harvested in 1995 revealed that FB contamination in Haimen was significantly higher than in Penlai. These 3-yearly surveys of corn samples (240 in total) demonstrated that corn harvested in Haimen was highly contaminated with FBs and that the contamination level, as well as positive rate in 1993 and 1995, were 10-50-fold higher than those in Penlai, suggesting FBs as a risk factor for promotion of PLC in endemic areas, along with the trichothecene DON. Co-contamination with AFs, potent hepatocarcinogens, was assumed to play an important role in the initiation of hepatocarcinogenesis.

The polymorphism interleukin 8 -251 A/T influences the susceptibility of Helicobacter pylori related gastric diseases in the Japanese population

BACKGROUND

Helicobacter pylori infection is associated with variable clinical outcomes, including gastroduodenal diseases, and genetic factors may be relevant in this process.

AIMS

We investigated the effects of an interleukin 8 (IL-8) gene polymorphism on the risk of gastroduodenal diseases, the degree of H pylori induced gastritis, and IL-8 gene transcription.

SUBJECTS

The study was performed in 244 healthy control subjects and 690 H pylori positive patients with non-cardia gastric cancer, gastric ulcer, duodenal ulcer, or gastritis.

METHODS

We identified the IL-8 -251 A/T polymorphism by direct sequence analysis, and measured the gastritis score and serum pepsinogen (PG). The transcriptional promoter activity of the IL-8 gene was assessed by luciferase assay.

RESULTS

IL-8 -251A was associated with a higher risk of gastric cancer and gastric ulcer. Patients carrying IL-8 -251A showed an increased risk of gastric cancer (odds ratios (OR) 2.01 (95% confidence interval (CI) 1.38-2.92)) and gastric ulcer (OR 2.07 (95% CI 1.37-3.12)). Compared with patients younger than 49 years, atrophy and metaplasia scores in the antrum were significantly higher and the PG I/II ratio significantly lower in -251A carriers than in T/T carriers. In the in vitro assay, IL-8 -251A showed enhanced promoter activity in response to IL-1beta or tumour necrosis factor alpha.

CONCLUSIONS

The IL-8 -251A allele may be associated with progression of gastric atrophy in patients with H pylori infection, and may increase the risk of gastric cancer and gastric ulcer in Japanese people.

Group 2 innate lymphoid cells and CD4+ T cells cooperate to mediate type 2 immune response in mice

BACKGROUND

Innate lymphoid cells (ILCs) play important roles in innate immunity and tissue remodeling via production of various cytokines and growth factors. Group 2 ILCs (ILC2s) were recently shown to mediate the immune pathology of asthma even without adaptive immunity. However, little is known about possible interactions between ILC2s and other immune cells. We sought to investigate the capacity of ILC2s to regulate effector functions of T cells.

METHODS

We isolated ILC2s from the lungs of naïve mice. We cultured CD4(+) T cells with ILC2s in vitro and examined the functions of these cell types. The mechanisms were investigated using blocking antibodies and cells isolated from cytokine-deficient mice. For the in vivo study, we adoptively transferred ILC2s and CD4(+) T cells into Il7ra(-/-) mice and subsequently exposed the mice to ovalbumin and a cysteine protease.

RESULTS

Lung ILC2s enhanced CD4(+) T-cell proliferation and promoted production of type 2 cytokines in vitro. The interaction between ILC2s and CD4(+) T cells involved costimulatory molecule OX40L and cytokine IL-4, which was mainly derived from ILC2s. Adoptive transfer of both ILC2 and CD4(+) T-cell populations, but not each population alone, into Il7ra(-/-) mice resulted in induction of a robust antigen-specific type 2 cytokine response and airway inflammation.

CONCLUSION

Lung ILC2s function to promote adaptive immunity in addition to their established roles in innate immunity. This novel function of ILC2s needs to be taken into account when considering the pathophysiology of asthma and other allergic airway diseases.

Helicobacter pylori infection prevents erosive reflux oesophagitis by decreasing gastric acid secretion

BACKGROUND

Helicobacter pylori infection is less prevalent and atrophic gastritis is less extensive in patients with reflux oesophagitis than those without it, but few studies have examined this relationship directly.

AIMS

We investigated the relationship between H pylori infection, acid secretion, and reflux oesophagitis in Japanese subjects.

SUBJECTS

A total of 105 patients with erosive reflux oesophagitis were compared with 105 sex and age matched patients without reflux oesophagitis.

METHODS

The diagnosis of H pylori infection was made by histological examination of gastric mucosal biopsy specimens, rapid urease test, and detection of serum IgG antibodies. Acid secretion was assessed by the endoscopic gastrin test.

RESULTS

H pylori infection was present in 36 patients with erosive reflux oesophagitis (34.3%) and in 80 control subjects (76.2%) (odds ratio 0.163, 95% confidence interval 0.09-0.29). Overall acid secretion was significantly greater in patients with reflux oesophagitis. Among H pylori positive patients, acid secretion was greater in patients with reflux oesophagitis than those without oesophagitis.

CONCLUSION

In Japan, erosive reflux oesophagitis occurs most often in the absence of H pylori infection and gastric hyposecretion. Even in the presence of H pylori infection, reflux oesophagitis is more likely to develop in patients without gastric hyposecretion. H pylori infection may inhibit reflux oesophagitis by inducing hypoacidity.

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.

Dietary nitrate generates potentially mutagenic concentrations of nitric oxide at the gastroesophageal junction

BACKGROUND & AIMS

Twenty-five percent of absorbed dietary nitrate is re-secreted in saliva, and 30% of this is reduced to nitrite by buccal bacteria. When saliva is swallowed, the acidic gastric juice reduces the nitrite to nitric oxide. The aim of this study was to examine the anatomic distribution of nitric oxide generation within the lumen of the upper gastrointestinal tract under basal conditions and after ingesting nitrate equivalent to that in salad portion.

METHODS

Using custom-made sensors, the dissolved luminal nitric oxide concentration and pH were measured at 1-cm increments for 2 minutes throughout the length of the stomach and distal esophagus in 15 Helicobacter pylori-negative healthy volunteers with and without ingestion of 2 mmol potassium nitrate. Serum nitrate and saliva nitrite concentrations were also monitored.

RESULTS

The nitrate ingestion increased mean (range) serum nitrate from 30 micromol/L (18-49) to 95 micromol/L (32-152), mean salivary nitrite from 36 micromol/L (19-153) to 252 micromol/L (32-600), and mean peak luminal nitric oxide concentration from 4.7 micromol/L (1.4-7.8) to 23.2 micromol/L (2.1-50) (P < 0.05 for each). After nitrate, the peak nitric oxide concentration occurred in 11 of the 15 (73%) subjects within 1 cm distal to the gastroesophageal pH step-up point. The mean nitric oxide concentration over the 1-cm segment immediately distal to the gastroesophageal pH step-up after nitrate was 7.5 micromol/L (range, 0.5-30.7) and was significantly higher than at all other sites. Nitric oxide concentrations greater than 50 micromol/L were observed at the precise location where neutral esophageal pH fell to acidic gastric pH.

CONCLUSIONS

Luminal generation of nitric oxide from dietary nitrate via salivary nitrite is maximal at the gastroesophageal junction and cardia. The high concentrations of nitric oxide generated may contribute to the high incidence of mutagenesis and neoplasia at this site.

Estrogen receptor beta is involved in the anorectic action of estrogen

OBJECTIVE

Estrogen has been implicated in feeding behavior and adiposity. This study was undertaken to elucidate the mechanism underlying the anti-obesity and anorectic action of estrogen and the role of estrogen receptor (ER) in the central nervous system.

METHODS AND RESULTS

Ovariectomy in 8-week-old female Wistar rats induced hyperphagia along with an increase in body weight and abdominal fat accumulation compared to control sham-operated rats. These changes were fully reversed by subcutaneous replacement of estradiol and were abrogated by pair-feeding. Then, the effects of intracerebroventricular infusion of estradiol, alone or in combination with antisense oligodeoxynucleotides (ODN), for ER in ovariectomized rats were examined. The estradiol group showed 10-20% lower daily food intake, and after the 2-week infusion period a 14% reduction in body weight with a similar reduction in abdominal fat compared to the vehicle group. The inhibitory effect of estradiol on food intake and body weight was blocked by co-administration of ER-beta antisense ODN, whereas ER-alpha antisense ODN did not show any influence.

CONCLUSION

These results indicate that ER-beta in the central nervous system is involved in the anorectic action of estrogen.

Correlation between flow-mediated vasodilatation of the brachial artery and intima-media thickness in the carotid artery in men

Endothelial dysfunction has been reported to be the initial step in atherosclerosis. A noninvasive technique that uses ultrasound to measure the intima-media thickness of the carotid artery has been applied to evaluate localized atherosclerosis. This study was undertaken to elucidate whether endothelial dysfunction in the brachial artery is related to the intima-media thickness of the carotid artery. Thirty-four men with atherosclerosis (mean+/-SE age 61+/-2 years) and 33 age-matched men without clinical atherosclerosis were examined. The intima-media thickness and plaque formation of the common carotid artery were assessed by B-mode ultrasonography. We also noninvasively measured brachial artery diameter by the same ultrasound machine when the subjects were at rest, during reactive hyperemia, which causes endothelium-dependent vasodilatation, and after sublingual administration of nitroglycerin, which causes endothelium-independent vasodilatation. The atherosclerosis group had a significantly greater intima-media thickness of the common carotid artery than did the control group (1. 02+/-0.04 versus 0.91+/-0.03 mm, P<0.05). The flow-mediated diameter (FMD) increase (percent FMD=DeltaD/D x 100) in the atherosclerosis group was significantly smaller than that in the control group (2. 8+/-0.4% versus 5.1+/-0.6%, P<0.01). A significant negative correlation between the intima-media thickness of the carotid artery and percent FMD was found in all of the subjects. On multiple regression analysis, percent FMD showed a significant negative correlation with the intima-media thickness of the common carotid artery. These findings support the concept that endothelial dysfunction is significantly related to atherogenesis.

Human mesangial cells and peripheral blood mononuclear cells produce vascular permeability factor

Vascular permeability factor, or vascular endothelial growth factor (VPF/VEGF) is a disulfide-linked dimeric glycoprotein of about 40 kD that promotes fluid and protein leakage from blood vessels. Various human tumor cell lines and cells including fetal vascular smooth muscle cells produce VPF/VEGF. Since glomerular mesangial cells (MC) are closely related to vascular smooth muscle cells, we examined whether cultured human MC produce VPF/VEGF. Northern blotting analysis revealed that cultured human MC expressed a 3.7 kilobases (kb) VPF/VEGF mRNA. Human peripheral blood mononuclear cells (PBMC) also expressed VPF/VEGF transcripts of 8.6 and 3.8 kb. Although the sizes of the transcripts suggested the existence of unique molecular species of VPF/VEGF mRNA in PBMC, RT-PCR analysis revealed that PBMC as well as human MC expressed 121, 165, and 189 amino acid-containing isoforms of VPF/VEGF, implying that there are no unique alternative splicing products of VPF/VEGF mRNA in PBMC. Fetal calf serum and 12-o-tetradecanoyl- phorbol-13-acetate (TPA) transiently enhanced VPF/VEGF mRNA expression in cultured human MC. Transforming growth factor-beta 1 enhanced VPF/VEGF mRNA expression in cultured human MC at least within 24 hours. Dexamethasone (DEX) inhibited the TPA-induced increase in VPF/VEGF mRNA expression, whereas DEX did not change the basal level. The DEX depressed the TPA-induced increase in VPF/VEGF mRNA expression is therefore probably a result of transcriptional control. VPF/VEGF protein was detected in cultured human MC with immunoperoxidase staining using anti-VPF/VEGF antibody. TPA increased VPF/VEGF protein levels as well as those of VPF/VEGF mRNA in cultured human MC.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in gastric acid secretion assayed by endoscopic gastrin test before and after Helicobacter pylori eradication

BACKGROUND

It remains controversial whether or not Helicobacter pylori infection causes altered gastric acid secretion. A novel test for evaluating gastric acid secretion (endoscopic gastrin test; EGT) has recently been developed.

AIM

To investigate by EGT the effects of H pylori eradication on the state of gastric acid secretion in patients with peptic ulcer.

METHODS

Twenty six patients with duodenal ulcer and 33 with gastric ulcer, for all of whom H pylori infection had been documented, were studied by EGT, histological examination of gastric mucosa, and measurement of plasma gastrin levels before and one and seven months after H pylori eradication.

RESULTS

In patients with duodenal ulcer, the mean EGT value before H pylori eradication was higher than that in H pylori negative controls, but it had decreased significantly seven months after the treatment. In contrast, the mean EGT value of patients with gastric ulcer before H pylori eradication was lower than that in H pylori negative controls, but it had increased one month after the treatment; this was followed by a slight decrease at seven months. In both groups, mean EGT values seven months after the treatment were not significantly different from the mean control value.

CONCLUSIONS

The reduced acid secretion in gastric ulcer patients and gastric acid hypersecretion in duodenal ulcer patients were both normalised after the clearance of H pylori.

Oxidative stress serves as a key checkpoint for IL-33 release by airway epithelium

BACKGROUND

Interleukin (IL)-33 is implicated in the pathophysiology of asthma and allergic diseases. However, our knowledge is limited regarding how IL-33 release is controlled. The transcription factor nuclear factor-erythroid-2-related factor 2 (Nrf2) plays a key role in antioxidant response regulation.

OBJECTIVE

The goal of this project was to investigate the role of cellular oxidative stress in controlling IL-33 release in airway epithelium.

METHODS

Complementary approaches were used that included human bronchial epithelial cells and mouse models of airway type-2 immunity that were exposed to fungus Alternaria extract. The clinically available Nrf2 activator 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid methyl ester (CDDO-Me) was used to evaluate the role of Nrf2-induced antioxidant molecules.

RESULTS

Human bronchial epithelial cells produced reactive oxygen species (ROS) when they were exposed to Alternaria extract. ROS scavengers, such as glutathione (GSH) and N-acetyl cysteine, prevented extracellular secretion of ATP and increases in intracellular calcium concentrations that precede IL-33 release. Administration of CDDO-Me to mice enhanced expression of a number of antioxidant molecules in the lungs and elevated lung levels of endogenous GSH. Importantly, CDDO-Me treatment reduced allergen-induced ATP secretion and IL-33 release by airway epithelial cells in vitro and protected mice from IL-33 release and asthma-like pathological changes in the lungs.

CONCLUSIONS

The balance between oxidative stress and antioxidant responses plays a key role in controlling IL-33 release in airway epithelium. The therapeutic potential of Nrf2 activators needs to be considered for asthma and allergic airway diseases.

Multiple combined therapy for severe Henoch-Schönlein nephritis in children

From 1980 through 1992, 14 children with Henoch-Schönlein nephritis (HSN) showing severe glomerular changes (grade IV or V) were given a multiple combined therapy with prednisolone, cyclophosphamide, heparin/warfarin, and dipyridamole, and were followed for 7.5+/-0.9 years. The period between the onset of nephritis and the start of therapy was 0.8+/-0.4 years. Ten patients underwent follow-up biopsy after therapy. The percentage of glomeruli having crescents/segmental lesions was significantly reduced after therapy (70%+/-5% vs. 42%+/-7%, P <0.01), due mainly to the resolution of crescents (51%+/-8% vs. 13%+/-5%, P <0.01). Thus, histological grade was significantly improved (5 grade IV and 5 grade V vs. 7 grade III and 3 grade IV, P <0.01). After an average follow-up period of 7.5 years, 9 patients showed normal urine and renal function, 4 showed minor urinary abnormalities, and 1 heavy proteinuria. No patient developed chronic renal insufficiency. These findings suggest that the multiple combined therapy could be effective. for histologically severe HSN, although a prospective controlled study should be performed.

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.

The effects of lansoprazole on erosive reflux oesophagitis are influenced by CYP2C19 polymorphism

BACKGROUND

The acid suppressive effect of lansoprazole is influenced by the P450 2C19 (CYP2C19) polymorphism.

AIM

To investigate whether the CYP2C19 genotype is related to the healing of erosive reflux oesophagitis during treatment with lansoprazole.

METHODS

Eighty-eight Japanese patients with erosive reflux oesophagitis were treated with a daily oral dose of 30 mg lansoprazole for 8 weeks. The CYP2C19 genotype, Helicobacter pylori infection status and serum pepsinogen I/II ratio were assessed before treatment. At 4 and 8 weeks, the healing of erosive reflux oesophagitis was evaluated endoscopically.

RESULTS

The healing rates were 57.1%, 69.2% and 72.7% at 4 weeks and 77.4%, 95.0% and 100% at 8 weeks in homozygous extensive metabolizers, heterozygous extensive metabolizers and poor metabolizers, respectively. At 8 weeks, the healing rate of erosive reflux oesophagitis was significantly lower in homozygous extensive metabolizers than in the other two groups (P < 0.05). The H. pylori status and serum pepsinogen I/II ratio had less influence than CYP2C19 polymorphism on the healing rate of erosive reflux oesophagitis.

CONCLUSIONS

The therapeutic effect of lansoprazole on erosive reflux oesophagitis is influenced by the CYP2C19 genotype status. Therefore, a test of CYP2C19 genotype may be useful for the medical treatment of reflux oesophagitis with lansoprazole.

Red wine polyphenols inhibit proliferation of vascular smooth muscle cells and downregulate expression of cyclin A gene

BACKGROUND

Red wine polyphenols have been shown to contribute to the "French paradox" phenomenon, which consists of lower morbidity and mortality from coronary heart disease in the French population. Although vascular smooth muscle cell (VSMC) proliferation plays an important role in the progression of atherosclerotic lesions, the effects of red wine polyphenols on VSMC proliferation have not been elucidated.

METHODS AND RESULTS

We extracted the total polyphenolic fraction from red wine (RW-PF) by column chromatography. Treatment with RW-PF showed a potent inhibitory effect on the proliferation and DNA synthesis of cultured rat aortic smooth muscle cells (RASMCs). In contrast, the inhibitory effect of RW-PF on the proliferation of bovine carotid endothelial cells was observed only at much higher concentrations. To elucidate the molecular mechanisms of this antiproliferative effect of RW-PF on RASMCs, we investigated the effects of RW-PF on cell cycle regulation. RW-PF downregulated the expression of cyclin A mRNA and cyclin A promoter activity. In addition, RW-PF decreased the binding of nuclear proteins to the activating transcription factor (ATF) site in the cyclin A promoter and downregulated the mRNA levels of transcription factors, cAMP-responsive element-binding protein (CREB), and ATF-1.

CONCLUSIONS

These results suggest that the downregulation of cyclin A gene expression may contribute to the antiproliferative effect of red wine polyphenols on RASMCs through the inhibition of transcription factor expression.

Helicobacter pylori infection inhibits reflux esophagitis by inducing atrophic gastritis

OBJECTIVE

Although it is widely accepted that Helicobacter pylori (H. pylori) infection is an important cause of atrophic gastritis, few studies have examined the relationship between H. pylori-induced atrophic gastritis and the occurrence of reflux esophagitis. The present study was aimed to examine the relationship between H. pylori infection, atrophic gastritis, and reflux esophagitis in Japan.

METHODS

A total of 175 patients with reflux esophagitis were compared with sex- and age-matched 175 control subjects. Diagnosis of H. pylori infection was made by gastric mucosal biopsy, rapid urease test, and serum IgG antibodies. Severity of atrophic gastritis was assessed by histology and serum pepsinogen I/II ratio.

RESULTS

H. pylori infection was found in 59 (33.7%) patients with reflux esophagitis, whereas it was found in 126 (72.0%) control subjects. The grade of atrophic gastritis was significantly lower in the former than in the latter. Among the H. pylori-positive patients, atrophic gastritis was milder in the patients with reflux esophagitis than in the patients without it.

CONCLUSIONS

These findings suggest that most cases of reflux esophagitis in Japan occur in the absence of H. pylori infection and atrophic gastritis, and it may also tend to occur in patients with milder gastritis even in the presence of H. pylori infection. Therefore, H. pylori infection may be an inhibitory factor of reflux esophagitis through inducing atrophic gastritis and concomitant hypoacidity.

Immunohistochemical study of alpha 1-5 chains of type IV collagen in hereditary nephritis

The distribution of alpha 1-5 chains of type IV collagen [alpha 1-5(IV)] in the glomerular basement membrane (GBM) and epidermal basement membrane (EBM) of 23 families with hereditary nephritis was examined by indirect immunofluorescence. These families were divided into three clinicopathological groups. Group I (10 families) patients showed a widespread "basket weave" pattern of the GBM and a family history of nephritis was present. Group II (6 families) patients showed a widespread "basket weave" change without a family history of nephritis. Group III (7 families) patients showed a widespread attenuation of the GBM but no "basket weave" change, and had a family history of nephritis and chronic renal failure. alpha 1(IV) and alpha 2(IV) were present in all affected and unaffected family members and controls. All normal family members and controls expressed alpha 3(IV), alpha 4(IV) and alpha 5(IV) in the GBM and alpha 5(IV) in the EBM in a diffuse pattern. All group I families and three of the group II families exhibited complete loss of the alpha 5(IV) antigen from the GBM and EBM in male patients, and segmental loss of the alpha 5(IV) antigen in female patients. In these families the alpha 3(IV) and alpha 4(IV) antigens were completely lost from the GBM in male patients with severe nephritis, whereas alpha 3(IV) alpha 4(IV) were present but diminished in male patients with mild nephritis. Three group II and all group III families expressed the alpha 3-5(IV) antigens in an identical manner to that of normal controls. These findings indicate that the heterogeneity of hereditary nephritis reflects a variety of aberrant expression patterns of alpha 3-5(IV) and that immunohistochemical examination of alpha 5(IV) in the EBM is a useful method for the diagnosis of X-linked Alport syndrome.

Atypical cystic lobule of the breast: an early stage of low-grade ductal carcinoma in-situ

The authors describe the characteristics of atypical cystic lobules (ACLs), which represent a step in the formation of low-grade ductal carcinoma in-situ. The authors define ACLs as a proliferation of luminal cells showing low-grade cytological atypia without architectural atypia. ACLs were compared with conventional hyperplasia, low-grade ductal carcinoma in-situ, and lobular neoplasia. 1) In about 40% of the cases, atypical cystic lobules merged with fully established micropapillary/cribriform ductal carcinoma in-situ. 2) Immunohistochemical staining for hormone receptors, keratin nineteen, and cyclin D1 revealed that atypical cystic lobules demonstrate a consistent immunophenotype, which differs from that of normal lobules and benign lesions and matches the one of low-grade ductal carcinoma in-situ. 3) ACLs are sometimes calcified. Osteopontin-positive histiocytes infiltrated all Kossa-positive (type II microcalcification) cribriform and comedo-type carcinomas and ACLs. The similarities in cytological and immunohistochemical features, the close proximity of the two types of proliferation, and the similarities with respect to calcification suggest that atypical cystic lobules represent an early stage in the formation of certain types of low-grade ductal carcinoma in-situ.

Expression of peroxisome proliferator-activated receptor gamma (PPARgamma) in rat aortic smooth muscle cells

Peroxisome proliferator-activated receptor gamma (PPARgamma), a member of nuclear receptors, is expressed at a high level in adipose tissue and plays an important role in adipocyte differentiation. In the present study, we identified the expression of PPARgamma in rat aortic smooth muscle cells (RASMC) using reverse transcription-polymerase chain reaction and gel mobility shift assay. In addition, to investigate whether PPARgamma in RASMC is functional or not, we examined the effect of two specific ligands for PPARgamma, a thiazolidinedione anti-diabetic agent, troglitazone, and 15-deoxy-Delta12,14-prostaglandin J2, on the transcriptional activity of PPAR responsive element (PPRE). A significant increase in the activity of PPRE by addition of these ligands was found. These results suggest that in RASMC, target genes for PPARgamma may be activated by specific ligands for PPARgamma through PPRE in their promoters. In conclusion, PPARgamma is expressed and functional in vascular smooth muscle cells.