(WHS-P93) NEWT PLASMA INHIBIT DIFFERENTIATION OF MOUSE FIBROBLASTS INTO MYOFIBROBLASTS AND CONTRIBUTE TO WOUND REGENERATION.
Friday, May 17, 2024
7:30 AM – 5:00 PM East Coast USA Time
While scar healing by fibrosis is a wound healing strategy that we mammals are equipped with, it is also the cause of many intractable diseases such as keloids and pulmonary fibrosis. Although numerous studies have been conducted to inhibit fibrosis, the inflammatory response that leads to fibrosis is also required for beneficial repair processes, so targeting it for disease treatment is still expected to be challenging. To identify fibrosis-suppressed regenerative therapeutic strategies, we focused on the special regenerative potential of newts, which belong to the salamander family of tailed amphibians. Many studies have shown that newts maintain a strong regenerative capacity throughout life without fibrosis even after reaching adulthood beyond metamorphosis. Considering that even amphibians with strong regenerative abilities lose or decline their regenerative abilities as they grow, it is likely that newts have an unknown regenerative factor. In this study, we report our findings that newt plasma may confer fibrosis-inhibitory properties on mouse fibroblasts across species. First, to determine the effect of newt plasma on mouse fibroblasts, we examined cell viability after the addition of newt plasma. To avoid variation due to individual differences, whole blood was collected from each of five blastema. After isolating plasma from the whole blood samples, cell viability at 72 hours was evaluated. The results showed that the administration of newt plasma within the range of 0.1% to 1% had no lethal effect on mouse fibroblasts. Next, we tested the inhibitory effect of the addition of newt plasma on fibrosis by using TGFβ1 to induce fibroblast differentiation into myofibroblasts in an assay. Fluorescent immunostaining using F-actin and αSMA as markers showed that the expression of both was attenuated by the addition of newt plasma. Quantitative evaluation using Western blotting confirmed that the addition of newt plasma reduced the amount of αSMA to the same level as the control group. This suggests that the addition of newt plasma may have inhibited the induction of differentiation into myofibroblasts. To further identify the location of fibrosis inhibitory factors, we focused on extracellular vesicles (EVs) and isolated EVs from newt plasma by ultracentrifugation. We performed the same experiment with the isolated EVs as with plasma addition, and found that the same effect was obtained. This suggests that newt plasma has the ability to suppress fibrosis across animal species, and that it is highly likely that plasma EVs contain factors that can suppress fibrosis. This research may offer new possibilities for regenerative medicine.