The Mechanism Of Platelet-Rich Plasma Impacts Investigation Research On The Hair Cycles

Background:Alopecia is a worldwide problem issue,one of the main type of Alopecia is androgen alopecia(AGA).Epidemiological investigation in China shows that 53.3%~63.9%of AGA patients has a genetic history,and the paternal line is significantly higher than the maternal.The current treatment for AGA patients mainly includes hair transplantation surgery and medication treatments.However,the surgical treatments for hair transplant are difficult to provide sufficient donor hair follicles for patients whom has massive area of hair losses.As for the medication treatments,such as finasteride,is also rejected by some patients due to its side effects.Therefore,a safe,effective and widely applicable treatment for androgen alopecia is urgently needed in the clinical practice.Platelet-Rich Plasma(PRP),is a new type of treatment for AGA,which has been attracted clinical attentions.PRP is a concentration of autologous platelets and plasma,preliminary animal experiments and clinical studies have suggested that PRP can promote the hair follicles in the hair loss area during the telogen phase and to re-enter to anagen phase to establish a new hair follicle cycle,prolong hair growth period and delay its conversion to catagen phase.As a new treatment for hair loss,it shows unique advantages,mechanism of PRP promoting hair growth cycle is not yet clear.This experiment is obtained PRP was injected into the subcutaneous of the back of mice using an animal model,and relevant tests were performed to explore the mechanism of PRP on the hair growth cycle.Objective:(1)Investigate the role of PRP in promoting hair growth;(2)To explore the mechanism of PRP on hair cycles;(3)It provides a theoretical basis for PRP micro-needle injection to promote hair regeneration in patients with alopecia.Method:(1)Platelet-rich plasma/Platelet-poor plasma was prepared100ml blood was taken from a healthy adults into the ice box,then centrifuge at 4℃ Celsius,PRP/PPP was obtained after two-step centrifugation.As differential centrifugation preparation by this group of PRP process under low temperature environment,so to speak as temperature control platelet rich plasma,namely t-PRP.(2)Preparation of a mouse model of t-PRP on hair cycles20 C57BL/6 mice aged 5～6 weeks were selected,and randomly divided into the experimental group(t-PRP group)or the control group(PPP group),with 10 mice in each group,then depilated the back hair of mice with depilatory cream.Divided into left and right halves from the midline of the mouse back,then t-PRP or PPP was subcutaneously injected into the left back,and the same amount of normal saline was injected into the right side.Injections were given every 3 days for a total of 3 injections.(3)Observe the influence of t-PRP or PPP injection on the hair cycle of mice and carry out relevant detectionC57BL/6 mice in the experimental group(t-PRP)and the control group(PPP)at different time periods were taken respectively.Observe the general view of the hair at the injection site and carry out relevant detection.After taking skin samples from the back of mice,then paraffin-embedded sections,tissue sections were stained with H&E,parallel protein chip detection.In the end,the results of protein chip detection were further verified by qRT-PCR and Western blot.Results:(1)The dorsal hair of mice at different periods(week 1,2,5,7)after injection of t-PRP/PPP/Nacl was observed respectively.It was found that the back hair of mice injected with t-PRP at week 2/5/7 was darker than that of the PPP group and the Nacl group,and the hair was longer than that of other groups,while there was no significant difference between the PPP group and the Nacl group.(2)Samples were taken from the back skin of mice at different periods(week I,2,5,7)after t-PRP/PPP/Nacl injection,and H&E staining showed that the back hair of the t-PRP group entered the growth period earlier than that of other groups.Protein chip detection showed that the amount of PDGF,Ki67,β-catenin protein in the back skin of the t-PRP injection group were significantly higher than that of the control group(PPP injection group)and the Nacl group.(3)According to the detection results of protein microarray,RNA levels of hair follicle cyclin-related proteins were detected.For example,samples were taken from the dorsal hair skin of mice at different periods(week 1,2,5,7)after t-PRP/PPP/Nacl injection,and the results were further verified by qRT-PCR and Western-blot,which were consistent with the above positive results.