Florinda Jiménez-Vega

Molecular characterization of the bifunctional VHDL-CP from the hemolymph of white shrimp Penaeus vannamei

A very high-density lipoprotein (VHDL) purified from the hemolymph of the white shrimp Penaeus vannamei is shown to be identical to the clotting protein (CP) previously reported from the same organism based on size, subunits and N-terminal amino acid sequence. The approximately 440-kDa protein, a homodimer of approximately 200-kDa subunits, was present in KBr gradient fractions ranging in density from 1.155 to 1.212 g/ml. Samples of VHDL after purification by strong cation exchange chromatography were subjected to electrophoresis on native polyacrylamide gels. Lipids associated with the VHDL were detected by Sudan Black and Oil Red O staining and comprise 9-15% of the purified protein. Circular dichroism of VHDL-CP indicates that the alpha-helix content of the VHDL-CP is 32%, while beta-sheets correspond to 33%, closely resembling the secondary structure of CP from the shrimp Penaeus monodon and, remarkably, the secondary structure of very high-density lipophorin E (VHDLpE) from the tobacco hornworm, Manduca sexta.

Single IB domain (SIBD) protein from Litopenaeus vannamei, a novel member for the IGFBP family

Several clones encoding for a peptide similar to insulin-like growth factor protein binding (IGFBP) were found in a Litopenaeus vannamei hemocytes cDNA library. Although IGFBP is constituted by two well defined domains (IB and tyroglobulin) joint by a flexible region; the shrimp transcript encoding only for the IB domain as confirmed by Northern analysis. The expression of this, single IB domain (SIBD)-containing protein is modified by bacteria inoculation suggesting a role in immune response. In addition, shrimp SIBD protein seems to be the common ancestor for the IGFBP superfamily.

Distribución geoespacial y detección del virus del dengue en mosquitos Aedes (Stegomyia) aegypti de Ciudad Juárez, Chihuahua, México

OBJETIVO: Determinar la distribucion de Aedes aegypti en Ciudad Juarez, Mexico, y evaluarlo como portador del virus del dengue. MATERIAL Y METODOS: Se colectaron mosquitos empleando minitrampas CDC. Se aplicaron tecnicas geoespaciales del vecino mas proximo y funcion K. Para evaluar la asociacion entre la presencia del vector y variables sociodemograficas se aplico la prueba de ji². Las pruebas de infeccion fueron mediante RT-PCR. RESULTADOS: Se capturaron 122 mosquitos hembra. Se demostro la tendencia de distribucion en conglomerado (R=-1.2995 p=0.05) del mosquito a los 4000 m pero ninguna de las variables sociodemograficas mostro asociacion significativa. Siete lotes evaluados fueron positivos para DEN-2, diez para DEN-3 y siete para ambos serotipos. CONCLUSIONES: Es el primer reporte de la presencia de mosquitos Aedes aegypti infectados con dengue en la region, lo que permitira promover su vigilancia con el fin de disminuir la probabilidad de ocurrencia de la enfermedad entre la poblacion fronteriza.

The expression of protein disulfide isomerase from Litopenaeus vannamei hemocytes is regulated by bacterial inoculation

A partial clone encoding a member of the protein disulfide isomerase (PDI) was isolated from a Litopenaeus vannamei hemocyte cDNA library. The 5?-end sequence was obtained by RACE. The complete sequence encodes for a 502-residues protein that contains two thioredoxin domains and the typical endoplasmic reticulum retention KDEL motif. Shrimp PDI is highly similar to the homologue protein described in both vertebrates and invertebrates. Changes in the shrimp PDI mRNA expression were observed after injection of Vibrio alginolyticus, suggesting that PDI is implicated in the immune defense system. This is the first report of a PDI in crustaceans.

Chitosan/poly(dl,lactide-co-glycolide) scaffolds for tissue engineering

Chitosan/poly(dl-lactide-co-glycolide) (Ch/dl PLG) composite scaffolds were fabricated by freeze-drying lyophilization, and were evaluated and compared for use as a bone regeneration scaffold through measurements of the compression mechanical properties of the porous scaffolds. Also, In vitro cell culture of Sprague–Dawley rat’s osteoblasts were used to evaluate the phenotype expression of cells in the scaffolds, characterizing the cellular adhesion, proliferation and alkaline phosphatase activity. The gene expression of osteocalcin, sialoprotein, alkaline phosphatase, Type I collagen and TGFβ1 were confirmed in the samples; moreover, it was confirmed, the mineralization by IR spectra and EDS analysis. Our results thus show that Ch/dl PLG scaffolds are suitable for biological applications.

ISOFORMS OF LITOPENAEUS VANNAMEI ANTI-LIPOPOLYSACCHARIDE AND ITS EXPRESSION BY BACTERIAL CHALLENGE

Abstract Anti-lipopolysaccharide factors have been described in arthropods, including penaeid shrimp. In this study, we characterize six antilipopolysaccharide-coding clones isolated from a cDNA library from L. vannamei hemocytes. Three different isoforms (named ALFLv1, ALFLv2 and ALFLv3) are observed, based on three nucleotide differences that produce three changes in amino acid sequence (Val11Ala, Val12Ala, Arg83Lys). Other single differences in nucleotide sequences were also noted, but they do not change the translated product. Considering that the signal peptide cleavage site occurs between Ala25 and Gln26, the substitutions Val11Ala and Val12Ala are not present in the mature protein. The mRNA steady state levels of ALFLv3, but not for ALFLv1 or ALFLv2, were up regulated by Vibrio alginolyticus inoculation. Thus, the differences among penaeid ALFs seem to be associated with the Arg83Lys substitution and its expression under bacterial inoculation.

DNA Methylation of Cellular Retinoic Acid-Binding Proteins in Cervical Cancer

This study determined the methylation status of cellular retinoic acid-binding protein (CRABP) gene promoters and associated them with demographic characteristics, habits, and the presence of human papilloma virus (HPV) in patients with cervical cancer (CC), low and high squamous intraepithelial lesions, and no intraepithelial lesion. Women (n = 158) were selected from the Colposcopy Clinic of Sanitary Jurisdiction II in Ciudad Juarez, Chihuahua, Mexico. Demographic characteristics and habit information were collected. Cervical biopsy and endocervical scraping were used to determine methylation in promoter regions by methylation-specific polymerase chain reaction technique. We found hemi-methylation patterns in the promoter regions of CRABP1 and CRABP2; there was 28.5% hemi-methylation in CRABP1 and 7.0% in that of CRABP2. Methylation in CRABP1 was associated with age (≥35 years, P = 0.002), family history of cancer (P = 0.032), the presence of HPV-16 (P = 0.013), and no alcohol intake (P = 0.035). These epigenetic changes could be involved in the CC process, and CRABP1 has the potential to be a predictive molecular marker of retinoid therapy response.

Krüppel-Like Factor 10 participates in cervical cancer immunoediting through transcriptional regulation of Pregnancy-Specific Beta-1 Glycoproteins

Cervical cancer (CC) is associated with alterations in immune system balance, which is primarily due to a shift from Th1 to Th2 and the unbalance of Th17/Treg cells. Using in silico DNA copy number analysis, we have demonstrated that ~20% of CC samples exhibit gain of 8q22.3 and 19q13.31; the regions of the genome that encodes the KLF10 and PSG genes, respectively. Gene expression studies demonstrated that there were no alterations in KLF10 mRNA expression, whilst the PSG2 and −5 genes were up-regulated by 1.76 and 3.97-fold respectively in CC compared to normal tissue controls. siRNA and ChIP experiments in SiHa cells have demonstrated that KLF10 participates in immune response through regulation of IL6, IL25 and PSG2 and PSG5 genes. Using cervical tissues from KLF10−/− mice, we have identified down-regulation of PSG17, −21 and −23 and IL11. These results suggest that KLF10 may regulate immune system response genes in cervical cancer among other functions. KLF10 and PSG copy number variations and alterations in mRNA expression levels could represent novel molecular markers in CC.