This week: Mitochondrial-initiated immune response involved in transplant rejection and a novel stimulation method enhances neuronal repair after stroke.
The news highlights:
Lenient regenerative medicine regulations: is economic competition to blame?
Mitochondrial-initiated immune response involved in transplant rejection
Novel cell stimulation method enhances neuronal repair after stroke
Regulatory bodies are key enforcers of standards concerning the safety and efficacy of new medicines and technologies. However, as economic, and sometimes political, pressure on these agencies builds, some suggest this drives leniency in the strict regulations they enforce. In a new editorial, Douglas Sipp (RIKEN; Tokyo, Japan) and Margaret Sleeboom-Faulkner (University of Sussex, UK) consider this proposition by evaluating whether pressure-reformed policies implemented in response to economically controversial regenerative medicine regulations in Japan and other countries, still effectively protect patients and strengthen health markets.
In the article, the authors argue that: “…when regulation does not support the scientific effort to establish the safety and efficacy of medical products, it may be brokered by interest groups, including industry, particular groups of scientists and patients, and policy-makers. In an international context, regulatory changes for short-term economic or political reasons in one country can have a cascading effect, leading to unforeseeable, detrimental consequences for the field of regenerative medicine at the global level.”
In a new study, researchers from the Transplant and Stem Cell Immunobiology lab at the University of California, San Francisco (UCSF; CA, USA), in collaboration with the Laboratory of Transplantation Genomics at the National Heart, Lung and Blood Institute (NHLBI; MD, USA) and Stanford University (CA, USA), have demonstrated that mitochondrial DNA can be altered during cell reprogramming. Further, researchers transplanted genetically matched donor cells, containing unmatched mitochondrial DNA, into recipient mice. Days later, scientists harvested immune cells from the recipient mice and found these to be reactive against the mitochondrial DNA of the transplanted cells.
Hannah Valantine, study co-author and lead Investigator at the Laboratory of Organ Transplant Genomics in the Cardiovascular Branch at NHLBI, commented: “This study uncovers a possible new mechanism by which transplants are rejected, and which might be leveraged in the future to develop better diagnostic and immunosuppressive agents.”
Neuronal regeneration following stroke is critical to brain function and patient recovery. In a novel study, researchers from Emory University School of Medicine, Atlanta Veterans Affairs Medical Center (both GA, USA) and Tzu Chi Foundation (Taiwan) detail a new, non-invasive cell stimulation technique that boosts optimal neuronal repair conditions and neuronal regeneration success. The team infused induced pluripotent stem cell-derived neural progenitor cells with an optochemogenetic fusion protein called luminopsin 3 (LMO3). LMO3 is reactive to the substrate coelenterazine (CTZ). In vitro stimulation of the LMO3-infused cells with CTZ increased the cells expression of components essential for synapse formation. Subsequent transplantation of the cells into the cortices of mice who had suffered stoke, and regular, intranasal CTZ transfusion, resulted in increased neuronal regeneration.
In the study, the authors concluded: “This study pioneers the generation and application of an optochemogenetics approach in stem cell transplantation therapy after stroke for optimal neural repair and functional recovery…The noninvasive repeated coelenterazine stimulation of transplanted cells is feasible for clinical applications. The synergetic effects of the combinatorial cell therapy may have significant impacts on regenerative approach for treatments of CNS injuries.”
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