V. E. Aguirre-Arzola

11 beta-hydroxysteroid dehydrogenase 2 promoter methylation is associated with placental protein expression in small for gestational age newborns

Highlights11&bgr;‐HSD2 protein expression is lower in placentas of SGA newborns.Placental 11&bgr;‐HSD2 expression is directly correlated to birthweight.HSD11B2 promoter methylation is higher in SGA placentas.AGA and SGA placentas have no variation in global placental methylation.Reduced 11&bgr;‐HSD2 protein expression may be modulated by methylation of the HSD11B2 promoter. ABSTRACT Small for gestational age infants have greater risk of developing metabolic diseases in adult life. It has been suggested that low birth weight may result from glucocorticoid excess in utero, a key mechanism in fetal programming. The placental enzyme 11‐beta hydroxysteroid dehydrogenase type 2 (11&bgr;‐HSD2, HSD11B2 gene) acts as a barrier protecting the fetus from maternal corticosteroid deleterious effects. Low placental 11&bgr;‐HSD2 transcription and activity have been associated with low birth weight, yet the mechanism regulating its protein expression is not fully understood. In the present study we aimed to analyze 11&bgr;‐HSD2 protein expression in placentas of adequate and small for gestational age (AGA and SGA, respectively) newborns from healthy mothers, and to explore whether 11&bgr;‐HSD2 protein expression could be modulated by DNA methylation. 11&bgr;‐HSD2 protein levels were measured by western blot in placental biopsies from term AGA and SGA infants (n = 10 per group). DNA methylation was profiled both globally and in the HSD11B2 promoter by liquid chromatography with UV detection and methylation‐specific melting curve analysis, respectively. We found lower placental 11&bgr;‐HSD2 protein expression and higher HSD11B2 promoter methylation in SGA compared to AGA. Promoter methylation was inversely correlated with both protein expression and, importantly, birth weight. No changes in global placental methylation were found. In conclusion, lower 11&bgr;‐HSD2 protein expression is associated with higher HSD11B2 promoter methylation, correlating with birth weight in healthy pregnancy. Our data support the role of 11&bgr;‐HSD2 in determining birth weight, providing evidence of its regulation by epigenetic mechanisms, which may affect postnatal metabolic disease risk.

ETIQUETAS DE SECUENCIAS EXPRESADAS DIFERENCIALES DE FRUTOS DE AGUACATE RAZA MEXICANA (Persea americana Mill. var. drymifolia)

In this study, Differential Expressed Sequence Tags (ESTs) of immature fruits of Persea americana Mill var. drymifolia of the state of Nuevo León, Mexico were developed and identified. Ten genotypes with fruits of different size and shape were selected to generate ESTs by the differential display technique. In total, 393 amplified differential fragments were obtained, 82 fragments were sequenced and edited for identification and comparison with NCBI nucleotide and protein databases. Forty sequences showed significant similarity to mRNA sequences and / or sequences of hypothetical or predicted proteins belonging to P. americana and / or other genera. Some sequences were related to enzymes such as flavanone-3-hydroxylase (F3H), lecithin-cholesterol acyltransferase, glutathione-S-transferase microsomal and pleiotropic drug resistance protein. With the information of the nucleotide composition of ESTs, primers could be designed to quantify expression levels by real-time RT-PCR of genes in different phenological stages of the fruit and to make comparisons among genotypes that allow determining alternative uses of their fruits.

Evidence of cross gene regulation of some virulence factors of Porphyromonas gingivalis by Streptococcus intermedius

Periodontal disease has been associated with poor dental care, which promotes the accumulation of bacteria and the development of diseases of the mouth. Porphyromonas gingivalis are anaerobic Gramnegative bacteria found in the subgingival plaque. They are largely responsible for chronic periodontal disease. Streptococcus intermedius is a Gram positive coccus found in the supragingival plaque. The objective of the present work was to evaluate the expression of several virulence genes of P. gingivalis in a mixed culture with S. intermedius using qPCR and heterologous microarrays. P. gingivalis ATCC 33277 and W83 and S. intermedius ATCC 27335 strains were cultured and total RNA was extracted using the High Pure RNA isolation kit. Oligodeoxynucleotides were designed to make multiple comparisons with organisms. Microarray was performed to identify gene expression. To quantify gene expression, cDNA samples from three different P. gingivalis:S. intermedius ratios were diluted 10-1, 10-2 and 10-3. The microarray experiment indicated that in P. gingivalis , 29 genes were upregulated. The putative function of upregulated genes was the biosynthesis of different metabolic pathways. Heterologous microarrays are a new approach that are useful for investigating gene expression. Keywords: Porphyromonas gingivalis, Streptococcus intermedius , periodontal disease, virulence genes, cross gene regulation. African Journal of Biotechnology Vol. 12(28), pp. 4498-4502

Identification and characterization of a Cry7-like protein of Bacillus thuringiensis GM-33 strain holotype for subsp. monterrey

V.E. Aguirre-Arzola, A. G, Alcazar-Pizana, L. J. Galan-Wong, H. A. Luna-Olvera, B.E. Rivera Chavira and B. Pereyra-Alferez 1 Instituto de Biotecnologia. Facultad de Ciencias Biologicas. Universidad Autonoma de Nuevo Leon. Pedro de Alba y Manuel L. Barragan S/N. Cd. Universitaria. San Nicolas de los Garza, NL. 66450. Mexico 2 Facultad de Ciencias Quimicas. Universidad Autonoma de Chihuahua. Av. Universidad S/N. Cd. Universitaria. Chihuahua, Apdo. Postal 669. c.p.31170, Mexico.