Genome-Wide Association Studies in Dogs and Humans Identify ADAMTS20 as a Risk Variant for Cleft Lip and Palate

Cleft lip with or without cleft palate (CL/P) is the most commonly occurring craniofacial birth defect. We provide insight into the genetic etiology of this birth defect by performing genome-wide association studies in two species: dogs and humans. In the dog, a genome-wide association study of 7 CL/P cases and 112 controls from the Nova Scotia Duck Tolling Retriever (NSDTR) breed identified a significantly associated region on canine chromosome 27 (unadjusted p=1.1 x 10-13; adjusted p= 2.2 x 10-3). Further analysis in NSDTR families and additional full sibling cases identified a 1.44 Mb homozygous haplotype (chromosome 27: 9.29 – 10.73 Mb) segregating with a more complex phenotype of cleft lip, cleft palate, and syndactyly (CLPS) in 13 cases. Whole-genome sequencing of 3 CLPS cases and 4 controls at 15X coverage led to the discovery of a frameshift mutation within ADAMTS20 (c.1360_1361delAA (p.Lys453Ilefs*3)), which segregated concordant with the phenotype. In a parallel study in humans, a family-based association analysis (DFAM) of 125 CL/P cases, 420 unaffected relatives, and 392 controls from a Guatemalan cohort, identified a suggestive association (rs10785430; p =2.67 x 10-6) with the same gene, ADAMTS20. Sequencing of cases from the Guatemalan cohort was unable to identify a causative mutation within the coding region of ADAMTS20, but four coding variants were found in additional cases of CL/P. In summary, this study provides genetic evidence for a role of ADAMTS20 in CL/P development in dogs and as a candidate gene for CL/P development in humans

Redox regulation of mitochondrial fission, protein misfolding, synaptic damage, and neuronal cell death: potential implications for Alzheimer’s and Parkinson’s diseases

Normal mitochondrial dynamics consist of fission and fusion events giving rise to new mitochondria, a process termed mitochondrial biogenesis. However, several neurodegenerative disorders manifest aberrant mitochondrial dynamics, resulting in morphological abnormalities often associated with deficits in mitochondrial mobility and cell bioenergetics. Rarely, dysfunctional mitochondrial occur in a familial pattern due to genetic mutations, but much more commonly patients manifest sporadic forms of mitochondrial disability presumably related to a complex set of interactions of multiple genes (or their products) with environmental factors (G × E). Recent studies have shown that generation of excessive nitric oxide (NO), in part due to generation of oligomers of amyloid-β (Aβ) protein or overactivity of the NMDA-subtype of glutamate receptor, can augment mitochondrial fission, leading to frank fragmentation of the mitochondria. S-Nitrosylation, a covalent redox reaction of NO with specific protein thiol groups, represents one mechanism contributing to NO-induced mitochondrial fragmentation, bioenergetic failure, synaptic damage, and eventually neuronal apoptosis. Here, we summarize our evidence in Alzheimer’s disease (AD) patients and animal models showing that NO contributes to mitochondrial fragmentation via S-nitrosylation of dynamin-related protein 1 (Drp1), a protein involved in mitochondrial fission. These findings may provide a new target for drug development in AD. Additionally, we review emerging evidence that redox reactions triggered by excessive levels of NO can contribute to protein misfolding, the hallmark of a number of neurodegenerative disorders, including AD and Parkinson’s disease. For example, S-nitrosylation of parkin disrupts its E3 ubiquitin ligase activity, and thereby affects Lewy body formation and neuronal cell death

Extracellular-Nitric Oxide-Mediated Platelet-cGMP Production in Type 2 Diabetics Correlates Inversely with Plasma Membrane Cholesterol Levels

Recently, we showed that the diffusion of nitric oxide (NO) and NO-mediated signaling was affected by the levels of plasma membrane cholesterol in fibroblasts. The generality of these observations, which would imply that perturbations in NO-signaling mediated by increased membrane cholesterol levels, could be a common pathological trigger in vascular cells, was tested in platelets from normal and dyslipidemic type 2 diabetic (T2D) subjects. Plasma LDL-cholesterol correlated directly with platelet plasma membrane cholesterol (Y=0.28X+0.16; R2=0.39). The average platelet plasma membrane cholesterol concentration was ~2-fold larger in T2D than in control subjects (P<0.05). Cyclic GMP production in response to exogenous NO was ~4-fold larger in controls than in T2D (P<0.05). Artificial elevation of membrane cholesterol resulted in ~50 % decrease in the initial rates of NO-uptake. Elevated plasma cholesterol could be a contributing factor to T2D-induced platelet hyperactivity, since it correlated with increased plasma membrane cholesterol, the attenuation of NO-diffusion into platelets and the lowering of cGMP biosynthesis

Contemporary Drug Synthesis

1993, has achieved with great commercial success. Like its predecessor ticlopidine (I),clopidogrel (2) is an ADP-dependent platelet aggregation inhibitor. The mechanisms ofaction for both ticlopidine (1) and clopidogrel (2) are the same - through the antagonismof the P2Y12 purinergic receptor and prevention of binding of ADP to the P2Y12receptor. However, both ticlopidine (1) and clopidogrel (2) are not active in vitro, but areactivated in vivo by cytochrome P450-mediated hepatic metabolism. Remarkably, theidentity of the active metabolite 5 of clopidogrel (2) was unknown until 1999: when itwas isolated after exposure of clopidogrel (2) or 2-0x0-clopidogrel (4) to human hepaticmicrosomes. It is noteworthy that ticlopidine (1) and clopidogrel (2) do not share acommon active metabolite

PBS-1086, a Rel Inhibitor of NF-κB, Ameliorates Collagen-Induced Arthritis in Mice

The family of nuclear factor-kappaB (NF-κB) transcription factors is intimately involved in the regulation of expression of numerous genes in the setting of the inflammatory response. Inflammation, cartilage degradation, cell proliferation, angiogenesis and pannus formation are hallmarks of the pathogenesis of both collagen-induced arthritis (CIA) in rodents and rheumatoid arthritis (RA) in humans. The aim of this study is to investigate the effect of PBS-1086, a ReI inhibitor of NF-κB, on the modulation of the inflammatory response in mice subjected to CIA in comparison to the effect of etanercept. CIA was induced in mice by an intradermal injection of bovine type II collagen (CII) emulsion and complete Freund's adjuvant (CFA) at the base of the tail. On day 21, a second injection of CII in CFA was administered. Mice developed erosive hind paw arthritis when immunised with CII in CFA. Macroscopic clinical evidence of CIA first appeared as peri-articular erythema and oedema in the hind paws. The incidence of CIA was 100% by day 28 in the CII challenged mice and the severity of CIA progressed over a 35-day period with a resorption of bone. The histopathology of CIA included erosion of the cartilage at the joint. Treatment with PBS-1086 starting at the onset of arthritis (day 21) ameliorated the clinical signs at days 21–35 and improved histological status in the joint and paw. In addition, it also reduced the neutrophil infiltration which is a key mediator of RA. In this study, we demonstrate that PBS-1086 exerts an anti-inflammatory effect during chronic inflammation and ameliorates the tissue damage associated with CIA. The anti-inflammatory activities of PBS-1086 are comparable to those of etanercept treatment

Test of an antifouling treatment on tuna fish-cages in Boston Bay, Port Lincoln, South Australia

Ib Svane, Anthony Cheshire & Jeremy Barnet