Numb ameliorates necrosis and inflammation in acute kidney injury induced by cisplatin.

Cisplatin induces acute renal failure in humans and mice.Tubular apoptosis, necrosis and inflammation are the primary pathogenesis of cisplatin-induced acute kidney injury(AKI). We previously reported that the depletion of Numb from proximal tubules exacerbates tubular cells apoptosis in cisplatin-induced AKI, however, the role of Numb in tubular necrosis and renal inflammation in cisplatin-induced AKI remains unclear. A mouse model of AKI was produced by cisplatin intraperitoneally injection in mice from proximal tubule-specific depletion of Numb (PT-Nb-KO) and their wild-type littermates (PT-Nb-WT) respectively. Renal Numb expression was determined by Western blotting. Renal morphological damage was examined by hematoxylin and eosin staining (H&E staining). Tubular necrosis was evaluated by histological study and the protein level of renal Mixed lineage kinase domain-like protein (MLKL) which is a molecular marker of necrosis. Leukocyte infiltration and pro-inflammatory cytokines was determined by immunostaining and quantitative real-time PCR (qRT-PCR) respectively.The protein level of Numb was dramatically decreased in kidneys of PT-Nb-KO mice compared with PT-Nb-WT mice. After cisplatin injection, a significant increase of tubular injury score and the protein level of renal MLKL were detected in PT-Nb-KO mice compared with those in PT-Nb-WT. In addition, the number of F4/80-positve and CD3-positive cells, markers for macrophages and neutraphils respectively, showed significantly increased in kidneys from PT-Nb-KO mice compared with those in PT-Nb-WT mice. Consistently, the gene expression of pro-inflammatory cytokines including TNF-α and MCP-1 in the kidneys was higher in PT-Nb-KO mice than those in PT-Nb-WT mice. Numb play additional protective role in cisplatin-induced AKI through ameliorating tubular necrosis and renal inflammation besides attenuating cisplatin-induced tubular apoptosis.

Locating QTLs controlling overwintering seedling rate in perennial glutinous rice 89-1 (Oryza sativa L.).

A new cold tolerant germplasm resource named glutinous rice 89-1 (Gr89-1, Oryza sativa L.) can overwinter using axillary buds, with these buds being ratooned the following year. The overwintering seedling rate (OSR) is an important factor for evaluating cold tolerance. Many quantitative trait loci (QTLs) controlling cold tolerance at different growth stages in rice have been identified, with some of these QTLs being successfully cloned. However, no QTLs conferring to the OSR trait have been located in the perennial O. sativa L. To identify QTLs associated with OSR and to evaluate cold tolerance. 286 F12 recombinant inbred lines (RILs) derived from a cross between the cold tolerant variety Gr89-1 and cold sensitive variety Shuhui527 (SH527) were used. A total of 198 polymorphic simple sequence repeat (SSR) markers that were distributed uniformly on 12 chromosomes were used to construct the linkage map. The gene ontology (GO) annotation of the major QTL was performed through the rice genome annotation project system. Three main-effect QTLs (qOSR2, qOSR3, and qOSR8) were detected and mapped on chromosomes 2, 3, and 8, respectively. These QTLs were located in the interval of RM14208 (35,160,202 base pairs (bp))-RM208 (35,520,147 bp), RM218 (8,375,236 bp)-RM232 (9,755,778 bp), and RM5891 (24,626,930 bp)-RM23608 (25,355,519 bp), and explained 19.6%, 9.3%, and 11.8% of the phenotypic variations, respectively. The qOSR2 QTL displayed the largest effect, with a logarithm of odds score (LOD) of 5.5. A total of 47 candidate genes on the qOSR2 locus were associated with 219 GO terms. Among these candidate genes, 11 were related to cell membrane, 7 were associated with cold stress, and 3 were involved in response to stress and biotic stimulus. OsPIP1;3 was the only one candidate gene related to stress, biotic stimulus, cold stress, and encoding a cell membrane protein. After QTL mapping, a total of three main-effect QTLs-qOSR2, qOSR3, and qOSR8-were detected on chromosomes 2, 3, and 8, respectively. Among these, qOSR2 explained the highest phenotypic variance. All the QTLs elite traits come from the cold resistance parent Gr89-1. OsPIP1;3 might be a candidate gene of qOSR2.