Background and objectives: Aminoguanidine (AMG) has been found to inhibit apoptotic cell death in hair follicle micrografts and improves the viability of isolated micrografts during the storage period in hair restoration surgery. In this study, we investigated the effect of AMG on messenger ribonucleic acid (mRNA) synthesis of growth factors in stored micrografts and primary cultures of follicle-derived cell populations.
Method: Hair follicles were obtained from 10 different patients undergoing routine micrograft transplant and were stored for 5 hours at room temperature in phosphate-buffered saline containing different concentrations of AMG. After a culture period of 72 hours, quantitative changes of mRNA for basic fibroblast growth factor (bFGF), insulin-like growth factor 1 (IGF-1), and vascular endothelial growth factor (VEGF) were determined by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Primary cell cultures of dermal papilla and outer root sheath cells were stimulated for 72 hours with AMG followed by RT-PCR measurement of growth factor mRNA.
Results: A dose-dependent induction of VEGF mRNA could be demonstrated in stored micrografts after stimulation with AMG (unstimulated: 1.0 [0.7-2.2]; AMG 10 pg/mL: 5.6 [3.1-9.7], p < .05; AMG 50 pg/mL: 6.9 [5.7-10.0], p < .05; AMG 100 microg/mL: 17.1 [14.1-22.3], p < .001). Expression of bFGF mRNA and IGF-1 mRNA levels was not influenced by AMG stimulation. Stimulation of cultured dermal papilla and outer root sheath cells demonstrated 14-fold induction of VEGF mRNA by AMG in outer root sheath cells (unstimulated: 1.0 [0.8-1.4]; AMG 100 pg/mL: 14.0 [12.5-16.1], p < .01), and no changes in VEGF mRNA levels were detected in dermal papilla cells.
Conclusions: Our study demonstrated induction of VEGF mRNA in stored micrografts by AMG. Although the clinical relevance in post-transplant hair growth and wound healing needs further evaluation, the possibility of actively influencing growth factor production in isolated micrografts during the storage period is the basis for the development of hair follicle growth-promoting storage solutions in the future.