Transgenic silkworm expression systems have been applied for producing various recombinant proteins. Knocking out or downregulating an endogenous silk protein is considered a viable strategy for improving the ability of transgenic expression systems to produce exogenous proteins. Here, we report the expression of human epidermal growth factor (hEGF) in a P25 gene knockout silkworm. The hEGF gene regulated by the P25 gene promoter was integrated into a silkworm’s genome. Five transgenic positive silkworm lineages were generated with different insertion sites on silkworm chromosomes and the ability to synthesize and secrete proteins into cocoons. Then, a cross-strategy was used to produce transgenic silkworms with a P25 gene knockout background. The results of the protein analysis showed that the loss of an endogenous P25 protein can increase the hEGF production to about 2.2-fold more than normal silkworms. Compared to those of transgenic silkworms with wild type (non-knockout) background, the morphology and secondary structure of cocoon silks were barely changed in transgenic silkworms with a P25 gene knockout background, indicating their similar physical properties of cocoon silks. In conclusion, P25 gene knockout silkworms may become an efficient bioreactor for the production of exogenous proteins and a promising tool for producing various protein-containing silk biomaterials.

The leucine zipper-like transcriptional regulator 1 (LZTR1) gene has been reported to be associated with many kinds of human diseases, including cardiac disease, Noonan syndrome, and schwannomatosis. In this study, peripheral blood mononuclear cells (PBMCs) derived from patient diagnosed with dilated cardiomyopathy (DCM) was successfully reprogrammed into the human induced pluripotent stem cells (iPSCs) line, harboring a distinct heterozygous mutation in the LZTR1 gene. The established patient-derived iPSCs expressed endogenous pluripotent markers, demonstrated the potential to differentiate into three germ layers (endoderm, mesoderm, and ectoderm), and exhibited a normal karyotype.