Role of erythropoietin in the angiogenic activity of bone marrow endothelial cells of MGUS and multiple myeloma patients

Increasing evidences suggest several biological roles for erythropoietin and its receptor (Epo and EpoR), unrelated to erythropoiesis, including angiogenesis. Here, we detected the expression of EpoR in bone marrow-derived endothelial cells from monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) patients (MGECs and MMECs, respectively) and assessed whether Epo plays a role in MGECs- and MMECs-mediated angiogenesis. We show that EpoR is expressed by both MGECs and MMECs even though at a higher level in the first ones. Both EC types respond to rHuEpo in terms of cell proliferation, whereas other responses, including activation of JAK2/STAT5 and PI3K/Akt pathways, cell migration and capillarogenesis are enhanced by Epo in MGECs, but not in MMECs. In addition, the conditioned media of both Epo-treated cells induce a strong angiogenic response in vivo in the chorioallantoic membrane assay, comparable to that of vascular endothelial growth factor (VEGF). Overall, these data highlight the effect of Epo on MGECs- and MMECs-mediated angiogenesis: MGECs are more responsive to Epo treatment than MMECs, probably because over-angiogenic phenotype of MMECs is already activated by their autocrine/paracrine loops occurring in the "angiogenic switch" from MGUS

ALLELE-SPECIFIC TRANSCRIPTIONAL ACTIVITY OF THE VARIABLE NUMBER OF TANDEM REPEATS OF THE INDUCIBLE NITRIC OXIDE SYNTHASE GENE IS ASSOCIATED WITH IDIOPATHIC ACHALASIA

Background: Polymorphisms of genes involved in the regulation of the immune response are risk factors for achalasia, but their contribution to disease pathogenesis is unknown. Nitric oxide is involved in both immune function and inhibitory neurotransmission. Objective: to assess the association and the functional relevance of the CCTTT inducible Nitric Oxide Synthase (NOS2) gene promoter polymorphism in achalasia. Methods: Genomic DNA was isolated from 181 achalasia patients and 220 controls. Genotyping of the (CCTTT)n repeats was performed by PCR and capillary electrophoresis, and data analyzed by considering the frequency of the different alleles. HT29 cells were transfected with iNOS luciferase promoter-reporter plasmids containing different (CCTTT)n. Results: The alleles’ distribution ranged from 7 to 18, with a peak frequency at 12 repeats. Analysis of the allele frequencies revealed that individuals carrying 10 and 13 CCTTT repeats were respectively less and more frequent in achalasia (OR 0.5, 95% CI 0.3-0.5 and OR 1.6, 95% CI 1-2.4, all p<0.05). Long repeats were also significantly associated with an earlier onset of the disease (OR 1.69, 95% CI 1.13-2.53, p=0.01). Transfection experiments’ revealed a similar allele-specific iNOS transcriptional activity. Conclusion: The functional polymorphism (CCTTT) of NOS2 promoter is associated with achalasia, likely by an allele-specific modulation of nitric oxide production

Prednisolone restores blood brain barrier damages in dystrophic MDX mouse

Although the glucocorticoids delay the progression of Duchenne muscular dystrophy (DMD) their mechanism of action is unknown. In our previous studies we demonstrated that in the mdx mice, an animal model of DMD, besides the muscle degeneration, serious damages of the blood-brain barrier (BBB) occur taking to enhanced vessels permeability and brain edema (1). Moreover, we observed that the mdx mice after α–methyl-prednisolone (PDN) treatment ameloriated the histopathological profiles and the excitation-contraction of the myofibers (2). In this study, we evaluated the effects of the PDN on the BBB of the mdx mice, by estimating the immunocytochemical and biochemical expression of endothelial ZO-1 and occludin, pericyte desmin, and glial GFAP and short dystrophin isoform Dp 71 proteins, used as BBB markers. In addition, we analyzed the expression of dystrophin associate proteins (DAPs) aquaporin-4 (AQP4) and α-β dystroglycan in parallel in both brain and muscles of PDN treated mdx as well as in control mice. Results showed in mdx PDN treated mice a significant increase of the mRNA and protein content of all the glial, pericyte and endothelial proteins as compared to untreated mdx. Moreover, by immunoprecipitation we demonstrated that the BBB alteration in the mdx mice were coupled with enhanced occludin and AQP4 phosphorylation degree which, instead, was reduced after PDN treatment. Finally we observed that AQP4 and α-β dystroglycan complex increases its mRNA and protein content in both PDN mdx brain and muscle fibers, compared with mdx mice where the perivascular glial membranes and the myofibers showed a light staining after immunofluorescence analysis . These data indicate that the PDN restores the BBB damages in the mdx mice by inducing in the glial cell the expression of GFAP, AQP4 and Dp71 proteins and in the pericytes and endothelial cells, of the desmin and ZO-1 proteins, which are deficient in the distrophic mice. Moreover, the reduction in the AQP4 and occludin phosphorylation degree coupled with their ankoring to glial and endothelial membranes in the PDN mdx mice suggests that the glial and endothelial cells may be a cellular target of the drug. Finally, the enhanced expression of DAPs AQP4 and α-β dystroglycan in both brain and myofibers of PDN treated mdx mice compared to untreated mdx ones suggest the PDN might ameliorate the brain vessels and muscles functions of the dystrophic mice by a restoring a correct links between DAPs proteins and the extracellular matrix. 1. Nico B et al. Glia, 42: 235-251. (2003). 2. Cozzoli A. et al., Neuropathol. Appl. Neurobiol. 37, 243-256 (2011)

Ulcerative colitis-risk loci on chromosomes 1p36 and 12q15 found by genome-wide association study.

Ulcerative colitis is a chronic inflammatory disease of the colon that presents as diarrhea and gastrointestinal bleeding. We performed a genome-wide association study using DNA samples from 1,052 individuals with ulcerative colitis and preexisting data from 2,571 controls, all of European ancestry. In an analysis that controlled for gender and population structure, ulcerative colitis loci attaining genome-wide significance and subsequent replication in two independent populations were identified on chromosomes 1p36 (rs6426833, combined P = 5.1 x 10(-13), combined odds ratio OR = 0.73) and 12q15 (rs1558744, combined P = 2.5 x 10(-12), combined OR = 1.35). In addition, combined genome-wide significant evidence for association was found in a region spanning BTNL2 to HLA-DQB1 on chromosome 6p21 (rs2395185, combined P = 1.0 x 10(-16), combined OR = 0.66) and at the IL23R locus on chromosome 1p31 (rs11209026, combined P = 1.3 x 10(-8), combined OR = 0.56; rs10889677, combined P = 1.3 x 10(-8), combined OR = 1.29)

Association between Polymorphisms in Antioxidant Genes and Inflammatory Bowel Disease

Inflammation is the driving force in inflammatory bowel disease (IBD) and its link to oxidative stress and carcinogenesis has long been accepted. The antioxidant system of the intestinal mucosa in IBD is compromised resulting in increased oxidative injury. This defective antioxidant system may be the result of genetic variants in antioxidant genes, which can represent susceptibility factors for IBD, namely Crohn's disease (CD) and ulcerative colitis (UC). Single nucleotide polymorphisms (SNPs) in the antioxidant genes SOD2 (rs4880) and GPX1 (rs1050450) were genotyped in a Portuguese population comprising 436 Crohn's disease and 367 ulcerative colitis patients, and 434 healthy controls. We found that the AA genotype in GPX1 is associated with ulcerative colitis (OR = 1.93, adjusted P-value = 0.037). Moreover, we found nominal significant associations between SOD2 and Crohn's disease susceptibility and disease subphenotypes but these did not withstand the correction for multiple testing. These findings indicate a possible link between disease phenotypes and antioxidant genes. These results suggest a potential role for antioxidant genes in IBD pathogenesis and should be considered in future association studies.info:eu-repo/semantics/publishedVersio