We explored the role of hypocretins in human narcolepsy through histopathology of six narcolepsy brains and mutation screening of Hcrt, Hcrtr1 and Hcrtr2 in 74 patients of various human leukocyte antigen and family history status. One Hcrt mutation, impairing peptide trafficking and processing, was found in a single case with early onset narcolepsy. In situ hybridization of the perifornical area and peptide radioimmunoassays indicated global loss of hypocretins, without gliosis or signs of inflammation in all human cases examined. Although hypocretin loci do not contribute significantly to genetic predisposition, most cases of human narcolepsy are associated with a deficient hypocretin system.
Recently, we cloned the human myo-inositol monophosphatase 2 (IMPA2) cDNA and established its map location to chromosome 18p11.2, a region previously implicated in bipolar disorder. Because the myo-inositol monophosphatase enzyme has been shown to be inhibited by lithium, an effective therapeutic agent for bipolar disorder, IMPA2 is a plausible positional and functional candidate gene. To permit comprehensive screening for variants we characterized the genomic structure and isolated the potential promoter of IMPA2. The gene was found to encode eight exons spanning ෂ27 kb. The proximal 1-kb 5Ј flanking region did not contain an obvious TATA box but multiple potential binding sites for Sp1 and consensus motifs for AP2 and other transcription factors were evident. Sequencing of the coding region and splice junctions in unrelated bipolar disorder patients detected novel variants. A missense mutation in exon 2, His76Tyr, was found in one patient. His76 is evolutionarily conserved and replacement with Tyr introduces a potential site for phosphorylation. The other polymorphisms included an RsaI polymorphism, IVS1-15GϾA, and a T → C silent mutation in the third nucleotide of codon 53 in exon 2. By Fisher's exact test the silent mutation showed a trend for association (P = 0.051) with bipolar disorder suggesting that further scrutiny of this gene is warranted. Molecular Psychiatry (2000) 5, 165-171.
Osteoarthritis (OA) is a chronic and debilitating disease of the knee joint. OA of the knee is initiated by physical damage and accumulated oxidative stress, followed by an exaggerated inflammation leading to cartilage damage. Currently, no effective and safe therapeutic option capable of restoring articular cartilage tissue and joint architecture is available. We here report a novel and highly bioavailable formulation of curcumin, labeled as Next Generation Ultrasol Curcumin (NGUC), which was 64.7 times more bioavailable than natural 95% curcumin extract as demonstrated in rat bioavailability studies. We further investigated the protective effect of NGUC against monosodium iodoacetate (MIA)‐induced knee OA in rats. Analysis of X-ray and histopathological images revealed that NGUC supplementation restored joint architecture and reduced swelling of joints induced by MIA. NGUC treatment caused a significant reduction in the levels of inflammatory mediators such as TNF-α, IL-1β, IL-6, COMP, and CRP, and expressions of MMP-3, 5-LOX, COX-2, and NFκB in synovial tissue of rats with MIA-induced OA. NGUC also decreased serum MDA level and increased the levels of antioxidant enzymes SOD, CAT, and GPX. Thus, our results indicate that a novel formulation of curcumin with enhanced bioavailability effectively ameliorates the pathophysiology of OA.
SummaryIntracellular signals triggered by DNA breakage flow through proteins containing BRCT (BRCA1 C-terminal) domains. This family, comprising 23 conserved phosphopeptide-binding modules in man, is inaccessible to small-molecule chemical inhibitors. Here, we develop Bractoppin, a drug-like inhibitor of phosphopeptide recognition by the human BRCA1 tandem (t)BRCT domain, which selectively inhibits substrate binding with nanomolar potency in vitro. Structure-activity exploration suggests that Bractoppin engages BRCA1 tBRCT residues recognizing pSer in the consensus motif, pSer-Pro-Thr-Phe, plus an abutting hydrophobic pocket that is distinct in structurally related BRCT domains, conferring selectivity. In cells, Bractoppin inhibits substrate recognition detected by Förster resonance energy transfer, and diminishes BRCA1 recruitment to DNA breaks, in turn suppressing damage-induced G2 arrest and assembly of the recombinase, RAD51. But damage-induced MDC1 recruitment, single-stranded DNA (ssDNA) generation, and TOPBP1 recruitment remain unaffected. Thus, an inhibitor of phosphopeptide recognition selectively interrupts BRCA1 tBRCT-dependent signals evoked by DNA damage.
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