The genetic underpinnings of late-onset degenerative disease have typically been determined by screening families for the segregation of genetic variants with the disease trait in affected, but not unaffected, individuals. However, instances of intrafamilial etiological heterogeneity, where pathogenic variants in a culprit gene are not shared among all affected family members, continue to emerge and confound gene-discovery and genetic counselling efforts. Discordant intrafamilial cases lacking a mutation shared by other affected family members are described as disease phenocopies.
View Article and Find Full Text PDFAmyotroph Lateral Scler Frontotemporal Degener
December 2014
Our objective was to present clinicopathologic evidence of anterior visual pathway involvement in patients with amyotrophic lateral sclerosis (ALS) secondary to a C9orf72 mutation. Two related patients from an extended pedigree with ALS and GGGGCC hexanucleotide repeat expansion in the C9orf72 gene (C9-ALS) underwent neuro-ophthalmologic examination. Following death and tissue donation of the younger ALS patient, histopathologic examination of the retina, optic nerve and central nervous system (CNS) was performed.
View Article and Find Full Text PDFHigh levels of NO generated in the vasculature under inflammatory conditions are usually attributed to inducible nitric-oxide synthase (iNOS), but the role of the constitutively expressed endothelial NOS (eNOS) is unclear. In normal human lung microvascular endothelial cells (HLMVEC), bradykinin (BK) activates kinin B2 receptor (B2R) signaling that results in Ca(2+)-dependent activation of eNOS and transient NO. In inflamed HLMVEC (pretreated with interleukin-1β and interferon-γ), we found enhanced binding of eNOS to calcium-calmodulin at basal Ca(2+) levels, thereby increasing its basal activity that was dependent on extracellular l-Arg.
View Article and Find Full Text PDFThe G protein-coupled receptors (GPCRs) are the largest class of membrane proteins that play key roles in transducing extracellular signals to intracellular proteins to generate cellular responses. The kinin GPCRs, named B1 (B1R) and B2 (B2R), are responsible for mediating the biological responses to kinin peptides released from the precursor kininogens. Bradykinin (BK) or kallidin (KD) are agonists for B2Rs, whereas their carboxypeptidase (CP)-generated metabolites, des-Arg(9)-BK or des-Arg(10)-KD, are specific agonists for B1Rs.
View Article and Find Full Text PDFKinin B1 and B2 receptors (kB1R and kB2R) play important roles in many physiological and pathological processes. In some cases, kB1R or kB2R activation can have overlapping or complementary beneficial effects, thus an activator of both receptors might be advantageous. We found that replacement of the C-terminal Arg in the natural kB2R activators bradykinin (BK) or kallidin (KD) with Lys (K(9)-BK or K(10)-KD) resulted in agonists that effectively stimulate the downstream signaling of both the kB1R and kB2R as measured by increased inositol turnover, intracellular calcium, ERK1/2 phosphorylation, arachidonic acid release and NO production.
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