Bold claim: A fully canine stem cell culture system is now possible because researchers engineered dog-derived scaffolding, avoiding any human components. But here’s where it gets controversial: does removing human materials truly eliminate cross-species risks, or merely shift them to a new canine-centered standard?
Canine induced pluripotent stem (iPS) cells can differentiate into any cell type, making them invaluable for studying common canine diseases and, in some cases, human conditions as well.
Culturing iPS cells requires a scaffold—an underlying substrate that cells can attach to and grow on. Without this scaffold, the cells either die or fail to differentiate properly.
Today’s culture substrates for canine iPS cells are predominantly derived from human recombinant proteins. While effective, these human-derived components are foreign to dog cells, potentially triggering immune reactions and complicating clinical applications.
A research team led by graduate student Kohei Shishida and Professor Shingo Hatoya at Osaka Metropolitan University’s Graduate School of Veterinary Science took a different approach. They bioengineered E. coli to produce vitronectin (VTN), a protein native to dogs, by inserting canine-derived genes. In essence, the bacteria acted as tiny factories to generate VTN that could serve as a scaffold for canine iPS cells, eliminating the need for human- or mouse-derived materials.
The results showed that the canine-derived VTN supported stem cell culture just as effectively as the human-derived version. The iPS cells retained their full differentiation potential, matching outcomes seen with standard media.
“This achievement is highly significant because it enables stable cultivation of canine iPS cells without human components,” Shishida explained. “It reduces cross-species contamination risks and opens the door to a fully canine culture system.”
For potential clinical translation, the team also explored a mutant variant, VTN-N, created by trimming a portion of the protein’s N-terminal region to remove parts that might be unnecessary or problematic. VTN-N performed comparably to human-derived VTN, even with a simplified structure. Future work will focus on optimizing manufacturing processes for VTN-N.
“This research brings regenerative medicine for dogs closer to reality, addressing intractable conditions such as heart disease, neurological disorders, and blood disorders,” said Professor Hatoya. “Canine-derived VTN can be produced stably and cost-effectively in E. coli, offering a foundational technology with wide-ranging applications from lab research to clinical use.”
The study appeared in Regenerative Therapy.
Declaration of Competing Interest
The authors declare no conflicts of interest.
About OMU
Osaka Metropolitan University, founded in Osaka, is among Japan’s largest public universities. It pursues societal advancement through knowledge convergence and world-class research. For more research news, visit https://www.omu.ac.jp/en/ and follow OMU on X (Twitter), Facebook, Instagram, and LinkedIn through the provided links.
