Diogo M.F. Silva

The expression and localization of leptin and its receptor in goat ovarian follicles.

Leptin, a hormone that was originally identified in adipocytes, has been implicated in the regulation of ovarian folliculogenesis through endocrine, autocrine and/or paracrine mechanisms. The aim of this study was to investigate the expression patterns of leptin (LEP) and its receptor (LEPRb) in different types of ovarian follicular cells from goats. In small follicles, the expression levels of LEP were higher (P<0.001) in granulosa cells than in theca cells, cumulus cells and oocytes. The expression of LEP in granulosa cells was higher (P<0.001) in small follicles than in large follicles. In large follicles, the expression of LEPRb was higher (P<0.05) in granulosa cells than in theca cells, cumulus cells and oocytes. Higher expression (P<0.05) of LEPRb was detected in granulosa cells isolated from large follicles than in granulosa cells isolated from small follicles. Immunohistochemical analyses revealed the presence of the LEP and LEPR proteins in follicles at all stages of development. The most intense staining for LEP and LEPR was observed in the cytoplasm of oocytes and the surrounding granulosa cells. In conclusion, it was demonstrated that leptin and its receptor are expressed at both the mRNA and protein levels in goat ovarian follicles. Furthermore, the presence of a leptin signaling system in the caprine ovary suggests a potential regulatory role for leptin in follicular development and the maturation of goat oocytes.

Identification and genetic characterization of classical swine fever virus isolates in Brazil: a new subgenotype

The classical swine fever (CSF) is a highly contagious viral disease of pigs and wild boar. The CSF causes great economic losses for pork production and the occurrence of the disease is notifiable to the OIE. The objective of this work was to identify and characterize CSF virus isolates from Brazil. Seven viral isolates were obtained and the full-length E2 sequences were analyzed. Phylogenetic analysis revealed a different segregation pattern between Brazilian isolates and members of subgenotype 1.1, forming a separate group within genotype 1. Genetic distance analysis suggested the existence of two new subgenotypes, designated subgenotypes 1.5 and 1.6.

Latex protein extracts from Calotropis procera with immunomodulatory properties protect against experimental infections with Listeria monocytogenes.

BACKGROUND The latex from the medicinal plant Calotropis procera is often used in folk medicine against infectious and inflammatory diseases. PURPOSE In this study, we investigate a protein fraction with immunomodulatory properties, named LPPI, against experimental infections, in vitro and in vivo, with a virulent strain of Listeria monocytogenes. STUDY DESIGN LPPI was exposed to cultured macrophages or Swiss mice and then challenged with L. monocytogenes. METHODS Peritoneal macrophages were obtained from Swiss mice, and cultured in 96-well microplates. Soluble latex proteins (LP) were subjected to fractionation by ion-exchange chromatography. The major peak (LPPI) was added into wells at 10 or 100µg/ml. Albumin (100µg/ml) was used for comparison between protein treatments. After incubation for 1h at 5% CO2/ 37°C, the supernatant was discarded and 0.2ml of L. monocytogenes overnight culture was added in the wells. Following 4h and 24h infection, the cytokine mRNA expression was evaluated as well as the number of intracellular colony forming units. Swiss mice (n=16) were injected intraperitoneally (i.p.) with LPPI (5 and 10mg/kg) while the control mice received albumin (10mg/kg) or LP (10mg/kg). After 24h, all animal groups were challenged with L. monocytogenes (10(6) CFU/ ml), also by i.p. route. RESULTS LPPI was not toxic to uninfected macrophages (pMØ) and significantly increased mRNA expression of TNF-α, IL-6, IL-1β and iNOS. Following infection, cell viability was reduced by 50% in albumin-treated pMØ (control); but only 17% in pMØ treated with LPPI at 100µg/ml. In this case, LPPI increased expression of TNF-α and IL-6 whereas the number of bacterial colony-forming units was reduced 100-fold in comparison to control groups. Swiss mice pretreated with LPPI showed dose-dependent survival rates that reached 80%, while mice that received albumin died 1-3 days after infection. After 24h infection, leukocyte migration to the infectious foci was high in LPPI-treated mice whereas the number of viable bacteria in the peritoneal fluid, liver and bloodstream were significantly reduced. CONCLUSION We conclude that LPPI present immunomodulatory properties that are beneficial for prevention of systemic bacterial infections caused by the intracellular bacteria L. monocytogenes.

Expression of angiogenic factors and luteinizing hormone receptors in the corpus luteum of mares induced to ovulate with deslorelin acetate

The effects of deslorelin acetate use in inducing ovulation need to be clarified to improve the results of equine embryo transfer. The mRNA abundance for angiogenic factors and LH receptor (LHR) in corpus luteum (CL) was studied in mares with natural (control group [CG]) and induced ovulation with deslorelin acetate (treatment group [TG]; follicles: ≥ 35 mm). Transrectal ultrasonography was used to verify the ovulation day, and on Days 4, 8, and 12 after ovulation (Day 0), CL samples were obtained through ultrasound-guided biopsy. The messenger RNA expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and LHR genes were analyzed by real-time polymerase chain reaction. A positive correlation was observed between VEGF and LHR (P < 0.00001, r = 0.78), and it was possible to detect higher LHR expression in the TG than in the CG on Day 4 (P < 0.05). Moreover, this expression was higher on Days 4 and 8 than on Day 12 in the TG. Basic fibroblast growth factor was also expressed in luteal tissue on all days for both groups; however, these differences were not significant. In conclusion, deslorelin acetate was effective for the induction of ovulation in mares, resulting in higher expression of LHR, especially on the fourth day after ovulation. In addition, VEGF expression was influenced by induced ovulation, with a lower level on Day 12, which is expected in nonpregnant mares.

Peptidases from Latex of Carica candamarcensis Upregulate COX-2 and IL-1 mRNA Transcripts against Salmonella enterica ser. Typhimurium-Mediated Inflammation

The immunomodulatory properties of a mixture of cysteine peptidases (P1G10) obtained from the fruit lattice of Carica candamarcensis were investigated. P1G10 was obtained from fresh latex samples by chromatography in a Sephadex column and initially administered to Swiss mice (n = 5; 1 or 10 mg/kg) via i.p. After 30 min, the mice were injected with carrageenan (0.5 mg/mouse) or heat-killed S. Typhimurium (107 CFU/mL; 100°C/30 min) into the peritoneal cavity. Afterwards, two animal groups were i.p. administered with P1G10 (n = 6; 1, 5, or 10 mg/Kg) or PBS 24 hours prior to challenge with live S. Typhimurium (107 CFU/mL). P1G10 stimulated the proliferation of circulating neutrophils and lymphocytes, 6 h after injection of carrageenan or heat-killed bacteria, respectively. Furthermore, survival after infection was dose-dependent and reached 60% of the animal group. On the other hand, control mice died 1–3 days after infection. The examination of mRNA transcripts in liver cells 24 h after infection confirmed fold variation increases of 5.8 and 4.8 times on average for IL-1 and COX-2, respectively, in P1G10 pretreated mice but not for TNF-α, IL-10, γ-IFN and iNOS, for which the results were comparable to untreated animals. These data are discussed in light of previous reports.

N-pentyl-nitrofurantoin induces apoptosis in HL-60 leukemia cell line by upregulating BAX and downregulating BCL-xL gene expression

BACKGROUND Nitrofurantoin is a nitroderivative antibiotic that has bactericidal activity against pathogens causing urinary tract infection. A few studies have reported that nitrofurantoin has cytotoxic activity against cancer cells; however, nitrofurans remain a poorly explored class of compounds with respect to their anticancer potential. The aim of this study was to investigate the anticancer effects of a nitrofurantoin derivative, n-pentyl-nitrofurantoin (NFP), on HL-60 leukemia cells. METHODS Cytotoxicity was assayed by the MTT assay. Cell morphology and phosphatidylserine externalization were visualized after Giemsa-May-Grunwald and annexin V staining, respectively. DNA content and mitochondrial depolarization were measured by flow cytometry. BAX and BCL-xL expression was examined by RT-PCR. RESULTS NFP was 3.8-fold more cytotoxic against HL-60 leukemia cells than against normal cells. NFP reduced the number of viable cells 24h after the treatment with a concomitant increase in the number of apoptotic cells indicated by the externalization of phosphatidylserine, DNA fragmentation, and mitochondrial depolarization. The mRNA levels of BAX increased, whereas the mRNA levels of BCL-xL decreased. CONCLUSION The results indicate that NFP induces apoptosis in HL-60 cells by upregulating BAX and downregulating BCL-xL.