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.

Induction of nuclear orphan receptor NGFI-B gene and apoptosis in rat vascular smooth muscle cells treated with pyrrolidinedithiocarbamate.

NGFI-B is one of the orphan nuclear receptors, and its gene is implicated in the apoptosis of T cells. The aim of this study was to investigate the expression and the role of NGFI-B in vascular smooth muscle cells (VSMCs). Pyrrolidinedithiocarbamate (PDTC) is a modulator of an oxidative state and is reported to induce apoptosis only when the density of VSMCs is low. Under low VSMC density (10 000 cells/cm(2)), addition of PDTC (0.1 to 10 micromol/L) caused apoptosis of VSMCs, which was confirmed by Hoechst 33258 staining under fluorescence microscopy. At low VSMC density, expression of NGFI-B mRNA was induced 1 hour after the addition of PDTC, peaking at 6 hours, and persisted for up to 12 hours. The protein level of NGFI-B was increased 4 hours after PDTC addition and persisted for up to 12 hours. Under low VSMC density, PDTC-induced expression of NGFI-B mRNA was correlated with the magnitude of apoptosis, which was quantified by enzyme immunoassay for histone-associated DNA fragments. In contrast, when the density of VSMCs was high (50 000 cells/cm(2)), PDTC did not induce apoptosis, and the expression of NGFI-B was only transient. This transient expression pattern was also seen when VSMCs were treated with phorbol ester, calcium ionophore, hydrogen peroxide, or angiotensin II, even at low cell density. We next investigated whether the NGFI-B gene may act as a transcription factor under treatment with PDTC by measuring the promoter activity of luciferase reporter plasmids that contained typical NGFI-B-responsive elements. The PDTC-induced transcriptional activity of NGFI-B was 2-fold higher at low cell density than at high cell density. These data demonstrate that NGFI-B can be induced in VSMCs and suggest that NGFI-B may play a role in PDTC-induced VSMC apoptosis.

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.

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.

Prostanoids regulate proliferation of vascular smooth muscle cells induced by arginine vasopressin.

The aim of the present study was to investigate the effect of arginine [Arg(8)]vasopressin (vasopressin) on proliferation of vascular smooth muscle cells and the mechanisms underlying the action of vasopressin. To clarify these issues, we used two different types of vascular smooth muscle cells, cultured adult rat aortic smooth muscle cells and A10 cells, a cell line derived from fetal rat aorta. Vasopressin (10(-8) to 10(-6) M) significantly stimulated the proliferation of rat aortic smooth muscle cells in a dose-dependent manner. In contrast, vasopressin significantly inhibited the proliferation of A10 cells. This inhibition was abolished when A10 cells were treated with indomethacin. Vasopressin stimulated the production of prostanoids several-fold in A10 cells but not in rat aortic smooth muscle cells. These effects were completely blocked by the vasopressin V(1) receptor antagonist, 1-¿1-[4-(3-acetylamino-propoxy)benzoyl]4-piperidyl¿-3, 4-dihydro-2(1H)-quinolinone (OPC21268), but not by the vasopressin V(2) receptor antagonist, (+/-)-5-dimethylamino-1-[4-(2-methylbenzoylamino)benzol]-2, 3,4,5-tetrahydro-1H-benzazepine hydrochloride (OPC31260). These results indicate that vasopressin has diverse effect on proliferation of vascular smooth muscle cells through the vasopressin V(1) receptor, depending on the production of growth regulatory prostanoids.

Cytokine-induced expression of parathyroid hormone-related peptide in cultured human vascular endothelial cells.

Parathyroid hormone-related peptide (PTHrP) is a potent vasodilatory peptide whose expression has been demonstrated in various tissues. The present study was undertaken to examine the regulation of PTHrP expression in cultured endothelial cells derived from human umbilical vein. Immunoradiometric assay revealed that the amount of PTHrP in the conditioned medium was increased by both tumor necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta) in both a time- and a dose-dependent manner. The induction of PTHrP mRNA was also observed, with a peak after 2 hours of incubation with both TNF-alpha and IL-1beta. Angiotensin II, endothelin-1, and arginine vasopressin had no affect on PTHrP production. Our results suggest that PTHrP produced in vascular endothelial cells in response to cytokines may modulate vascular function as a local factor.

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.

[Randomized prospective trial of gentian violet with dibutyryl cAMP and povidone-iodine with sugar as treatment for pressure sores infected with methicillin-resistant Staphylococcus aureus in elderly patients].

A randomized prospective study was done to evaluate the two treatments for pressure sores infected with methicillin-resistant Staphylococcus aureus in elderly patients: Gentian violet plus dibutyryl cAMP (GVcAMP, n = 8) and povidone-iodine plus sugar (IS, n = 11). Age, underlying diseases, and nutritional status did not differ between the two groups. Specimens were obtained biweekly from the pressure sores and were cultured. The percentage of culture dishes with no methicillin-resistant S. aureus was 93% for the patients given GVcAMP, but only 74% for those given IS (p < 0.01). By the 14th week after the start of treatment, the mean area of the pressure sores in the GVcAMP group had decreased to 45% of the area at the start of treatment. In the IS group, the decrease was smaller to 56% of the area before treatment. No local or systemic adverse effects occurred in either group. GVcAMP is useful to treat pressure sores infected with methicillin-resistant S. aureus.

Identification of arginine vasopressin mRNA in rat aortic smooth muscle cells.

We investigated the expression of mRNA for arginine vasopressin in vascular smooth muscle cells and A10 cells using reverse transcription-polymerase chain reaction and Northern blot analysis. Arginine vasopressin mRNA was identified both in rat aortic smooth muscle cells and A10 cells, suggesting that arginine vasopressin is locally produced in vascular smooth muscle cells. Arginine vasopressin, a potent vasoconstrictor, may modulate vascular function in an autocrine or paracrine fashion.

[The importance of the host nutritional and immune status on the prognosis of urinary tract infection in the elderly].

This study was performed to evaluate the role of the nutritional and immune status on the prognosis of urinary tract infections (UTI) in the elderly. 192 patients among the 790 inpatients were diagnosed as UTI. Age-related increase in the prevalence of UTI was accompanied with poor prognosis in the patients with hypoalbuminemia (< 2.6 g/dl) and lymphocytopenia (< 700/mm3). To study the immunologic basis for susceptibility to UTI in the aged further, we compared the T-cell functions between outpatients without serious disease and inpatients with chronic UTI. The absolute numbers of lymphocyte, OKT3 (pan T-cell marker), OKT4 (Helper/Inducer marker) and Interleukin (IL)-2 as well as serum albumin concentration were decreased in the patients with UTI. A prospective study was done to confirm that these nutritional and immunological changes become risk factors in the prognosis of UTI with long-term and low-dose chemotherapy. In the patients continued with bacteriuria (Non-responders, n = 6), serum albumin concentration and IL-2 production were significantly lower than the patients who became free from bacteriuria (Responders, n = 7). These results suggest that poor nutrition-related immune dysfunction contributes to the vulnerability of elderly patients to UTI and becomes risks for he prognosis of UTI.

Sialates and negative charge on the surface of syncytiotrophoblastic cells of full-term placentae in toxemic patients.

In the syncytiotrophoblastic surface of the toxemic full-term placentae, the sialates and their consequent negative charging were studied by both electron microscopic histochemistry (Ferritin method) and Western blot analysis. Evidence is presented showing (1) that the reactions with both the ferritin labelled Limulus Polyphemus Agglutinin (LPA-ferritin), specific to sialates, and the cationized ferritin, specific to a negative charge, decrease in the specimens of toxemic placentae, (2) that the density of sialates in placentae of severe gestational proteinuria or/and hypertension is statistically lower than that of severe gestational edema, and (3) that there is no difference between the blotted bands in normal placentae and toxemic ones regardless of the severity of the toxemia. These results indicate that the reduction of the surface negative charging is demonstrated in toxemic syncytiotrophoblasts and appears to be secondary to the decrease in the amount of sialate.