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: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.
