Project description:A small molecule, AT7867, promotes proliferation of human pluripotent stem cell-derived pancreatic progenitor cells (PPCs), yet detailed mechanisms of its proliferative effect were not fully understood. Here, we performed cell-based siRNA screening on a subset of genes to reveal that WNT7B is a growth factor of human PPCs as previously shown in mouse pancreas development. Although recombinant proteins had no in vitro activity, feeder cell lines stably expressing Wnt7a or Wnt7b enhanced PPC proliferation. Further analyses showed that canonical Wnt signaling pathway was not affected by AT7867 treatment as well as Wnt7a and Wnt7b. Knockdown of a non-canonical Wnt pathway component, PKCα, and its downstream substrate, MARCKS, blocked PPC proliferation suggesting a requirement of this pathway. Phosphoproteome analysis revealed that AT7867 inhibited Yin Yang 1 (YY1) phosphorylation at Ser118, which directly or indirectly regulated expression of WNT7B in PPCs. Taken together, non-canonical Wnt signaling mediated by WNT7B plays a critical role for the expansion of human PPC population that is a promising alternative cell source to generate β cells for the cure of diabetes.
Project description:A small molecule, AT7867, promotes proliferation of human pluripotent stem cell-derived pancreatic progenitor cells (PPCs), yet detailed mechanisms of its proliferative effect were not fully understood. Here, we performed cell-based siRNA screening on a subset of genes to reveal that WNT7B is a growth factor of human PPCs as previously shown in mouse pancreas development. Although recombinant proteins had no in vitro activity, feeder cell lines stably expressing Wnt7a or Wnt7b enhanced PPC proliferation. Further analyses showed that canonical Wnt signaling pathway was not affected by AT7867 treatment as well as Wnt7a and Wnt7b. Knockdown of a non-canonical Wnt pathway component, PKCα, and its downstream substrate, MARCKS, blocked PPC proliferation suggesting a requirement of this pathway. Phosphoproteome analysis revealed that AT7867 inhibited Yin Yang 1 (YY1) phosphorylation at Ser118, which directly or indirectly regulated expression of WNT7B in PPCs. Taken together, non-canonical Wnt signaling mediated by WNT7B plays a critical role for the expansion of human PPC population that is a promising alternative cell source to generate β cells for the cure of diabetes.
Project description:Inflammation is a key component of pathological angiogenesis. Here we induce cornea neovascularisation using sutures placed into the cornea, and sutures are removed to induce a regression phase. We used whole transcriptome microarray to monitor gene expression profies of several genes
Project description:Few studies have assessed the patterns of parasite populations of rodents over a longitudinal gradient in Chile. In this work, the gastrointestinal helminthic fauna of invasive rodents in Chile was examined to assess the association between their presence/absence and abundance with latitude, host sex, and host body condition, and to assess the coexistence and correlation of the abundance between parasite species. Rodents were obtained from 20 localities between 33 and 43°S. Helminths were extracted from the gastrointestinal tract and identified morphologically. Overall, 13 helminth taxa were obtained. The most frequently identified parasite species was Heterakis spumosa, and the most abundant was Syphacia muris, while Physaloptera sp. was the most widely distributed. No locality presented with a coexistence that was different from that expected by chance, while the abundance of five helminthic species correlated with the abundance of another in at least one locality, most likely due to co-infection rather than interaction. Host sex was associated with parasite presence or abundance, and female sex-biased parasitism was notably observed in all cases. Body condition and latitude presented either a positive or negative association with the presence or abundance of parasites depending on the species. It is notable that the likely native Physaloptera sp. is widely distributed among invasive rodents. Further, gravid females were found, suggesting spillback of this species to the native fauna. The low frequency and abundance of highly zoonotic hymenolepid species suggest that rodents are of low concern regarding gastrointestinal zoonotic helminths.
Project description:Analysis of hormone effects on irradiated LBNF1 rat testes, which contain only somatic cells except for a few type A spermatgogonia. Rats were treated for 2 weeks with either sham treatment (group X), hormonal ablation (GnRH antagonist and the androgen receptor antagonist flutamide, group XAF), testosterone supplementation (GnRH antagonist and testosterone, group XAT), and FSH supplementation ((GnRH antagonist, androgen receptor antagonist, and FSH, group XAFF). Results provide insight into identifying genes in the somatic testis cells regulated by testosterone, LH, or FSH.
Project description:Analysis of LBNF1 rat testes from controls, containing both somatic and all germ cell types and from irradiated rats in which all cells germ cells except type A spermatgogonia are eliminated. Results provide insight into distinguishing germ and somatic cell genes and identification of somatic cell genes that are upregulated after irradiation.