Suppression of matrix metalloproteinase-9 by prostaglandin E(2) in peritoneal macrophage is associated with severity of endometriosis

Decreased phagocytotic ability of macrophages has been reported to be associated with the severity of endometriosis, although the underlying mechanism remains uncharacterized. Expression and secretion of matrix metalloproteinase (MMP)-9 by macrophages is a means to degrade the extracellular matrix of cells that are designated for phagocytosis. Here, we describe the regulation of MMP-9 expression and activity in peritoneal macrophages of women with endometriosis. Results demonstrated that peritoneal macrophages isolated from women with endometriosis have decreased levels of protein and enzyme activity of MMP-9. Treatment of macrophages with peritoneal fluid obtained from patients with severe endometriosis inhibited MMP-9 expression and gelatinase activity. Further investigation identified prostaglandin (PG) E(2) as the major factor in the peritoneal fluid that inhibited MMP-9 activity. The inhibitory effect of PGE(2) was mediated via the EP2/EP4-dependent PKA pathway. Furthermore, expression of tissue inhibitor of metalloproteinase-1, tissue inhibitor of metalloproteinase-2, and RECK in macrophages was not affected by treatment with PGE(2), indicating the effect of PGE(2) on suppressing MMP-9 activity was not mediated by up-regulation of its inhibitor. Our results suggest that decreased phagocytotic capability of peritoneal macrophage in patients with endometriosis may be caused by PGE(2)-mediated decreases in MMP-9 expression.     

Endometrial breakdown in women using Norplant is associated with migratory cells expressing matrix metalloproteinase-9 (gelatinase B)

Norplant, subdermally implanted slow-release levonorgestrel, is an effective and widely used contraceptive agent but has a high rate of discontinuation due to unacceptable abnormal uterine bleeding. Matrix metalloproteinases (MMPs) are expressed in normal cycling endometrium and are postulated to be responsible for the tissue breakdown at menstruation. We have compared the immunolocalization of MMP-9 and migratory cells in endometrium from Indonesian women using Norplant with normal controls. Positive MMP-9 immunostaining was observed intracellularly within stromal and intravascular leukocytes and extracellularly in areas of tissue lysis adjacent to these migratory cells. The MMP-9 positive cells were identified as neutrophils, eosinophils, CD3+ T-cells and macrophages. Quantitative assessment revealed that the number of MMP-9 positive cells, neutrophils and eosinophils were significantly increased in those endometrial biopsies from Norplant users displaying a shedding morphology and in normal controls at menstruation. There was no correlation between the number of MMP-9 positive cells and the number of bleeding days reported. Endometrial immunostaining for tissue inhibitor of metalloproteinases was similar in Norplant users and normal controls. These results suggest that MMP-9, an enzyme capable of degrading basement membrane components, may be involved in endometrial breakdown in women using Norplant.     

A polymorphism in the matrix metalloproteinase-9 promoter is associated with increased risk of preterm premature rupture of membranes in African Americans

Fetal membrane rupture is associated with increased expression of matrix metalloproteinase-9 (MMP-9) and matrix degradation. We have determined the functional significance of a variable number tandem repeat and a single nucleotide polymorphism (SNP) in the MMP-9 gene on promoter activity and their association with preterm premature rupture of membranes (PPROM). The 14 CA-repeat allele was a stronger promoter than the 20 CA-repeat allele in amnion epithelial cells and WISH amnion-derived cells, but in THP-1 monocyte/macrophage cells the 14 and 20 CA-repeat alleles had similar activities. An SNP at -1562 did not significantly affect promoter activity. A case-control study of African American neonates revealed that the 14 CA-repeat allele was more common in newborns delivered of mothers who had PPROM than in those delivered at term. There was no association between the -1562 SNP and PPROM. We conclude that there are cell host-dependent differences in MMP-9 promoter activity related to CA-repeat number and that fetal carriage of the 14 CA-repeat allele is associated with PPROM in African Americans.     

Plasmodium falciparum AARP1, a giant protein containing repeated motifs rich in asparagine and aspartate residues, is associated with the infected erythrocyte membrane.

During Plasmodium falciparum asexual intraerythrocytic development, the host's cell plasma membrane is modified by the insertion of parasite proteins. One or more of these modifications mediate the cytoadherence of infected erythrocytes to host vascular endothelium. However, these surface antigens can be the target of cytophilic antibodies which promote phagocytosis of the infected erythrocyte. It has been proposed that antibodies directed to epitopes rich in asparagine play an important role in this process, which has promoted efforts to isolate the corresponding gene(s). We describe here P. falciparum asparagine- and aspartate-rich protein 1 (PfAARP1), a new giant (circa 700-kDa) protein associated with the infected erythrocyte membrane which is rich in asparagine and aspartate residues due to the presence of nine blocks of repeats. Topology analysis predicts that PfAARP1 has multiple transmembrane domains and at least five external loops. Human antibodies immunopurified against a sequence composed exclusively of asparagine and aspartate amino acids derived from PfAARP1 label the surface of the infected erythrocyte, demonstrating that such motifs are exposed. Interestingly, external loop 4 of PfAARP1 contains repetitions of these residues, and their possible role as a target of cytophilic antibodies is discussed.     

Influenza A virus NP protein expressed in insect cells by a recombinant baculovirus is associated with a protein kinase activity and possesses single-stranded RNA binding activity.

Influenza A virus NP protein, the phosphoprotein associated with viral RNA in ribonucleoprotein (RNP) complexes, has been expressed at high levels (approximately 100 mg/liter cells) in insect (Sf9) cells by a baculovirus recombinant, and was localized almost entirely in the nuclei of these cells. NP was purified by immuno-affinity chromatography, and purified NP was shown to autophosphorylate and to phosphorylate casein in a cAMP-independent reaction. Furthermore, purified NP was able to bind to ssRNA as demonstrated by a mobility shift of ssRNA in non-denaturing gels. The binding of NP to ssRNA caused a diminution of its kinase activity in proportion to binding.     

Rs1894720 polymorphism is associated with the risk of age-related cataract by regulating the proliferation of epithelial cells in the lens via the signalling pathway of MIAT/miR-26b/BCL2L2

IntroductionCataracts caused by old age are one of the most frequent causes for blindness and poor vision worldwide. In this study, we aimed to clarify the possible role of rs1894720 polymorphism in the pathogenesis of age-related cataract.Material and methodsRs1894720 polymorphism genotype was detected by TaqMan. Bioinformatics analysis, luciferase assay, real-time PCR, western blot, and protein density analysis were conducted to establish the correlations between MIAT and miR-26b as well as between BCL2L2 and miR-26b. Flow cytometry and MTT assay were also performed to observe the effect of MIAT/miR-26b/BCL2L2 signalling pathway on the status of cell apoptosis and viability.ResultsMIAT functioned as an endogenous competing RNA to sponge miR-26b. In addition, BCL2L2 was identified as a target of miR-26b. Therefore, the expression of miR-26b was obviously suppressed by MIAT or anti-miR-26b, while the mRNA and protein expression of BCL2L2 was up-regulated in the presence of MIAT or anti-miR-26b. Moreover, the positive effect of MIAT on BCL2L2 expression was exerted via inhibition of the expression of miR-26b. In addition, the cells transfected with MIAT or anti-miR-26b showed suppressed expression of caspase-3 and reduced apoptosis index but higher cell viability, indicating that MIAT could suppress cell apoptosis via inhibition of miR-26b expression. Furthermore, the subjects carrying the GT and TT genotypes of single-nucleotide polymorphism (SNP) rs1894720 were associated with a higher risk of age-related cataracts, as indicated by their odds ratio (OR) and p-values.ConclusionsRs1894720 SNP could down-regulate the expression of MIAT, thus leading to reduced BCL2L2 expression and enhanced epithelial cell apoptosis in the lens, eventually increasing the incidence of age-related cataract.     

Increase in HDL-C concentration by a dietary portfolio with soy protein and soluble fiber is associated with the presence of the ABCA1R230C variant in hyperlipidemic Mexican subjects

BackgroundA dietary portfolio has been used to reduce blood lipids in hyperlipidemic subjects. To increase the effectiveness of these dietary treatments in specific populations, it is important to study the genetic variability associated with the development of certain types of hyperlipidemias. Low plasma high-density lipoprotein cholesterol (HDL-C) levels are the most common dyslipidemia in Mexican adults and are coupled with the presence of the ABCA1 R230C genotype. Therefore, the aim of this study was to assess the response of HDL-C concentration to a dietary portfolio in a group of Mexican hyperlipidemic subjects with ABCA1R230C (rs9282541) and R219K (rs2230806) polymorphisms.MethodsForty-three hyperlipidemic subjects (20 men and 23 women) were given a low saturated fat (LSF) diet for one month, followed by a LSF diet that included 25 g of soy protein and 15 g of soluble fiber daily for 2 months. We analyzed two ABCA1 polymorphisms and studied their association with serum lipids before and after treatment.ResultsHyperlipidemic subjects with the ABCA1 R230C genotype showed lower HDL-C concentrations at the beginning of the study and were better responders to the dietary treatment than subjects with the ABCA1 R230R genotype (+ 4.6% vs. + 14.6%) (p = .05). According to gender and the presence of the R230C genotype, women responded more significantly to the dietary treatment, reflected by an increase of 21.9% in HDL concentration (p = .022), than women with R230R genotype who only experienced an increase of 2.7% in HDL-C concentration. There was no association between the presence of the ABCA1 R219K variant (p = .544) and HDL concentration.ConclusionHyperlipidemic Mexican subjects with the ABCA1 R230C genotype showed lower HDL-concentrations and were better responders to dietary portfolio treatments for increasing HDL-C concentrations than subjects with the R230R genotype.     

PfCG2, a Plasmodium falciparum protein peripherally associated with the parasitophorous vacuolar membrane, is expressed in the period of maximum hemoglobin uptake and digestion by trophozoites

A Plasmodium falciparum gene closely linked to the chloroquine resistance locus encodes PfCG2, a predicted 320-330kDa protein. In the parasitized erythrocyte, PfCG2 expression rises sharply in the trophozoite stage and is detected in electron-dense patches along the parasitophorous vacuolar membrane (PVM), in the cytoplasm and in the digestive vacuole (DV). Results of extraction and partitioning experiments show that PfCG2 is a peripheral membrane protein. Exposure of trophozoite-infected erythrocytes to trypsin-containing buffer after streptolysin O permeabilization indicates that PfCG2 is exposed to the erythrocyte cytosol at the outer face of the PVM. PfCG2 is highly susceptible to hydrolysis by aspartic and cysteine proteases and shows dose-dependent accumulation in the presence of protease inhibitors. These results suggest that PfCG2 is delivered from the outside face of the PVM to the DV, where it is broken down by parasite proteases. PfCG2 interacts with erythrocyte cytoplasm and may be associated with processes of hemoglobin uptake and digestion by erythrocytic-stage parasites.     

Circulating antibodies to a conserved epitope of the Chlamydia trachomatis 60-kDa heat shock protein is associated with decreased spontaneous fertility rate in ectopic pregnant women treated by salpingectomy

PROBLEM: This prospective study was aimed to evaluate whether non-invasive clinical and serologic parameters of tubal disease are predictive for subsequent spontaneous conception and pregnancy outcome after first episode of ectopic pregnancy (EP). METHOD OF STUDY: Overall, 144 women aged <35 years were enrolled. Outcome of subsequent spontaneous conception was analyzed after 3 years and compared with clinical parameters and antibody responses to Chlamydia trachomatis and epitopes of the 60-kDa chlamydial heat shock protein (CHSP-60). RESULTS: Antibody response to a conserved epitope of CHSP-60 (amino acids, aa 260-277) was independently correlated with both decreased spontaneous conception and term delivery rates (adjusted odds ratios, OR: 3.6 and 5.4, respectively). CONCLUSION: Presence of circulating antibodies to a conserved epitope of the CHSP-60 is associated with a lower spontaneous conception rate, and increased likelihood of adverse pregnancy outcome in women treated by salpingectomy for first episode of EP.