Prostate cancer cell proliferation and angiogenesis in different obese mice models.

Obesity has been associated with increased incidence and aggressiveness of prostate cancer. Although controversial, several studies suggest that leptin could influence tumour cell growth and proliferation. The main goal of this study was to assess cellular growth of prostate adenocarcinoma cells in obese mice with different endogenous hormonal environments in what relates to leptin circulating levels and sensitivity. Four groups of mice (n = 6/group) were used, namely obese mice with congenital non-functioning leptin receptor OBR (db/db), obese mice with congenital leptin deficiency (ob/ob), mice with diet induced obesity (DIO) and normal weight C57BL/6J mice (control). All groups of mice were injected subcutaneously with 3.0 x 10(5) RM1 cells/500 microl PBS (murine prostate carcinoma androgen insensitive cells) and tumour growth and angiogenesis were evaluated 14 days after inoculation. The tumours induced in ob/ob and DIO mice were significantly larger (P < 0.001) while those induced in db/db mice were significantly smaller (P = 0.047), when compared with controls. Morphometric analysis revealed that mitotic index and Ki-67 positive nuclear density, both cell proliferation markers, were also significantly lower in the tumours of db/db mice (P < 0.001) when compared to controls. An inverse correlation was observed between leptin plasma levels and tumour weight (r = -0.642, P < 0.001), mitotic index (r = -0.646, P < 0.01) and Ki-67 positive nuclear density (r = -0.795, P < 0.001). These results suggest that high leptin concentrations are not favourable to RM1 cell growth and proliferation. On the contrary, high plasma leptin levels were associated with less cellular proliferation and angiogenesis in vivo.

Chronic exposure of rats to occupational textile noise causes cytological changes in adrenal cortex.

Chronic exposure to industrial noise and its effects on biological systems. Occupational exposure to noise may result in health disorders. Our aim was to evaluate the effects of chronic exposure to high-intensity noise of textile industry cotton rooms on the adrenal morphology. The environmental noise of a cotton-mill room from a large textile factory of Northern Portugal was recorded and reproduced by an adopted electroacoustic setup in a sound-insulated animal room where the rats were housed. The sounds were reproduced at the original levels of approximately 92 dB, which was achieved by equalization and distribution of sound output in the room. Wistar rats were submitted to noise exposure, in the same time schedule as employed in textile plants. After one, three, five, and seven months, the adrenals were collected and analyzed by light microscopy. Analyzed by multivariate analysis of variance and post hoc Bonferroni correction for multiple comparisons of the means between the groups. Noise exposure induced time-dependent changes in adrenal cortex, with decrease of zona fasciculata (ZF) and increase of zona reticularis volumes, together with a significant depletion of lipid droplet density in ZF cells of exposed rats, in comparison to control rats. Chronic exposure of rats to textile industry noise triggers cytological changes in the adrenals that suggest the existence of a sustained stress response.

Sleeve gastrectomy and gastric plication in the rat result in weight loss with different endocrine profiles.

BACKGROUND: Restrictive bariatric surgery procedures currently used include adjustable gastric banding, sleeve gastrectomy (SG), and gastric plication (GP), of which the last two techniques still lack sufficient data and long-term studies on weight loss, surgical complications, resolution of comorbidities, and mechanisms of weight loss. Therefore, gastric plication and sleeve gastrectomy as a standalone procedure are still considered experimental. Our aim was to analyze the effects of SG and GP on body weight, food intake, and endocrine profile. METHODS: Forty-four male Wistar rats were randomized into six weight-matched groups and submitted either to SG, GP, or sham-operated. Sham-operated rats were divided into pair-fed and fed ad libitum controls, one for each procedure. Animals were followed up for 21 days after surgery, while body weight and food intake were recorded daily, when fasting ghrelin, leptin, insulin and glucose plasma levels, and ghrelin expression in the stomach were measured. RESULTS: Rats submitted to SG and GP showed a significant decrease in body weight gain to the same extent as rats pair-fed to the surgical groups when compared to sham-operated fed ad libitum controls. After surgery, SG rats showed no difference in body composition, ghrelin, leptin, insulin, or glucose levels, while GP rats displayed lower body fat content and leptin levels compared to controls. Ghrelin was also lower in GP rats compared to sham-operated pair-fed rats. Ghrelin expression displayed a pattern similar to circulating ghrelin. CONCLUSIONS: SG and GP result in weight loss, although with differences in body composition and metabolic and endocrine profiles.

Immunization against active ghrelin using virus-like particles for obesity treatment.

Ghrelin is a gut hormone that stimulates food intake. In physiological conditions, ghrelin plasma levels rise with fasting and decrease after meals. Obese individuals have low fasting ghrelin levels that rise after food restriction, which is pointed out as a reason for the difficulty in maintaining weight loss. Some bariatric surgery procedures prevent rise in ghrelin levels with weight loss and this has been hypothesised to contribute to the long-term success of the treatment. The main goal of this study was to develop a safe and effective anti-ghrelin vaccine for obesity, through the chemical conjugation of ghrelin with a virus like particle, namely NS1 protein tubules from the Bluetongue Virus (BTV) using a hetero-bifunctional cross linker. Male adult C57BL/6 mice, with a normal weight and with diet-induced obesity (DIO), were randomized into six weight matched groups (n=6/group) and each group of mice received three intra-peritoneal injections with two weeks intervals, containing either 75 µg of ghrelin- NS1 immunoconjugate, 75 µg of NS1 or PBS. Our data show that immunized animals present increasing titres of anti-ghrelin antibodies, while their cumulative food intake significantly decreased and energy expenditure was significantly enhanced, although there were no significative changes in body weight.Vaccinated DIO mice also displayed significant decrease of NPY gene expression in the basal hypothalamus reflecting a decrease in central orexigenic signals. This study suggests that this anti-ghrelin vaccine has a positive impact on energy homeostasis and may be an additional therapeutical tool to be used with diet and exercise for obesity treatment.

Insulin prevents leptin inhibition of RM1 prostate cancer cell growth.

The association between obesity and cancer is controversial: whereas several epidemiological, clinical and research studies using cancer cell lines have supported that high levels of insulin and leptin could favor prostate cancer development and dissemination, other studies have demonstrated opposite effects or even absence of association. The main goal of this study was to evaluate the in vitro proliferation of murine androgen insensitive prostate carcinoma cells RM1 in the presence of leptin and insulin. After assessing and confirming the presence of leptin and insulin receptors in RM1 cells by immunocytochemistry, cells were cultured in the presence of different concentrations of leptin (0, 25, 50, 100 and 200 ng/mL), insulin (0, 50, 100, 150 and 200 nM) or leptin plus insulin ( 25 ng/ml + 50 nM; 50 ng/ml + 100 nM; 100 ng/ml + 150 nM; 200 ng/ml + 200 nM; 25 ng/ml + 150 nM; 100 ng/ml + 50 nM of leptin plus insulin, respectively). Cell proliferation was evaluated by assessing the percentage of resazurin reduction, a surrogate marker of cell metabolic rate. Leptin significantly decreased the percentage of resazurin reduction in all studied concentrations while there was only a slight or non significant difference in RM1cell proliferation in the presence of insulin or insulin combined with leptin when compared with control. These results show that leptin decreases RM1 prostate cancer cell proliferation at the studied concentrations, while insulin is able to antagonize the leptin inhibition of RM1 prostate cancer cell growth in vitro. The difference in cell growth that is modulated by the various hormonal environments may explain the heterogeneous behavior of prostate cancer in the obese human population.

Virulência e formação de biofilme microbiano por Enterococcus faecalis isolados de swabs cloacais de frangos de corte infectados com Eimeria spp / Virulence and biofilm formation by Enterococcus faecalis isolates from cloacal swabs of broilers infected with Eimeria spp

A dinâmica da microbiota no trato gastrointestinal (TG) de animais pode ser afetada por patógenos, tais como Eimeria spp. Os enterococos são bactérias saprófitas que colonizam o TG de mamíferos e aves. A influência sobre a microbiota intestinal está relacionada com a capacidade de adaptação das bactérias em se aderir às células hospedeiras e de colonizar as células das mucosas. O objetivo deste estudo foi analisar a frequência de genes de virulência ace, agg e operon do bopABCD em Enterococcus faecalis isolados de swabs cloacais de frangos de corte desafiados com Eimeria spp e alimentados com dietas padrões suplementadas ou não com anticoccidiano (monesina) e também avaliar a capacidade dessas cepas em formar biofilmes sob condições in vitro. Um total de 70 E. faecalis foram selecionadas e o gene agg foi mais freqüente em cepas isoladas de frangos de corte alimentados com anticoccidiano (92,3%) quando comparado ao grupo que não recebeu anticoccidiano (70,5%). Por outro lado, os genes ace e do operon bopABCD não demostraram nenhuma diferença significativa entre os dois grupos de frangos (P>0,005). Os E. faecalis isolados de frangos de corte alimentados com anticoccidiano demostraram uma maior frequência de fortes aderentes quando crescendo em meio suplementado com glicose (92,3-88,5%) e urina (77%), quando comparado com enterococos isolados de frangos que não receberam anticoccidiano. Observou-se que E. faecalis isolados de frangos tratados com anticoccidiano mostraram uma maior frequêencia dos genes dos fatores de virulência e de perfil de fortes formadores de biofilme, o que indica uma melhor adaptação dos isolados em ambiente intestinal saudável.

The microbiota dynamics in the gastrointestinal tract (GT) of animals can be disrupted by pathogens, such as Eimeria spp. Enterococci are saprophytic bacteria that colonize the GT of mammals and birds. The influence on the intestinal microbiota is related to the adaptive capacity of bacteria to adhere to host cells and colonize the mucosal cells. The aim of this study was to analyze the frequency of virulence genes ace, agg and bopABCD operon in Enterococcus faecalis isolated from cloacal swabs of broilers challenged with Eimeria spp. and fed with a standard diet supplemented or not with anticoccidial (monensin), and, also to evaluate for the ability of these strains to form biofilms under in vitro conditions. A total of 70 E. faecalis were selected and the agg gene was more frequent in strains isolated from the broilers treated with anticoccidial (92.3%) when compared to the group that not received anticoccidial (70.5%). On the other hand, the ace and bopABCD operon genes showed no significant difference between the two groups of broilers (P>0.005). The E. faecalis isolated from the broilers treated with anticoccidial showed a higher frequency of strong biofilm formation when growing in medium supplemented with glucose (92.3-88.5%) and urine (77%) when compared with enterococci isolated from broilers that not received anticoccidial. It was observed that E. faecalis isolated from broilers treated with anticoccidial showed a higher frequency of virulence factors genes and stronger biofilms formation, indicating better adaptation of the isolates in healthy intestinal environment.