Transgenic overexpression of human LY6K in mice suppresses mature T cell development in the thymus.

Lymphocyte antigen 6 family member K (LY6K) is upregulated in a number of types of cancer and promotes tumor cell proliferation and metastasis. In addition, LY6K is involved in tamoxifen resistance in breast cancer. However, the in vivo molecular mechanism of LY6K has not yet been investigated. In the present study, transgenic mice overexpressing human LY6K (hLY6K) were generated using the pMAMneo vector, and the effect of LY6K upregulation in vivo was investigated. A total of 4 transgenic mice were generated, and the gene copy number was examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RT-qPCR demonstrated that mRNA of hLY6K was overexpressed in the thymus and spleen of the transgenic mice compared with wild-type mice. Flow cytometric analysis demonstrated that the proportions of B and T cells in the spleen were similar in wild-type and transgenic mice; however, the proportion of thymic mature T cells decreased in the transgenic mice, while there was an increase in the proportion of naïve T cells. These findings suggest that the overexpression of LY6K suppresses T cell development, and that LY6K is a potential therapeutic target for cancer.

Three-dimensional brain-like microenvironments facilitate the direct reprogramming of fibroblasts into therapeutic neurons.

Biophysical cues can improve the direct reprogramming of fibroblasts into neurons that can be used for therapeutic purposes. However, the effects of a three-dimensional (3D) environment on direct neuronal reprogramming remain unexplored. Here, we show that brain extracellular matrix (BEM) decellularized from human brain tissue facilitates the plasmid-transfection-based direct conversion of primary mouse embryonic fibroblasts into induced neuronal (iN) cells. We first show that two-dimensional (2D) surfaces modified with BEM significantly increase the generation efficiency of iN cells and enhance neuronal transdifferentiation and maturation. Moreover, in an animal model of ischaemic stroke, iN cells generated on the BEM substrates and transplanted into the brain led to significant improvements in locomotive behaviours. We also show that compared with the 2D BEM substrates, 3D BEM hydrogels recapitulating brain-like microenvironments further promote neuronal conversion and potentiate the functional recovery of the animals. Our findings suggest that 3D microenvironments can boost nonviral direct reprogramming for the generation of therapeutic neuronal cells.