The Effects Of Low Frequency Electromagnetic Field On The Hair Growth, Expression Of KGF And β-catenin In Mice

【Objective】This study aims to observe effects of the low frequency electromagnetic field(LFEMF)on hair growth in C57BL/6mice,the expression of KGF and β-catenin, K15-positivecells and Ki67-positive cells. To find new therapeutic strategies to achieve hair regrowth.【Methods】The female C57BL/6adult mice were plucked hair shafts by wax/resin(1:1)toinduce the next anagen, and randomly divided into the control group and the low frequencyelectromagnetic field group which was exposed to electromagnetic field(50Hz、5mT),30min/d,for16days,take photos everyday. After exposing the low frequency electromagnetic field for3days,9days and16days, we graded the hair growth, and then harvested the skin specimens, andused the HE staining to assess for hair follicle growth, RT-PCR and Western-blot to test theexpression of keratinocyte growth factor, IF to observe the expression location of KGF, RT-PCRto test the expression of β-catenin, IHC and IF to observe Ki67-positive cells and K15-positivecells in the hair follicle.【Results】1.Pictures showed that: at nine days, the colour of mouse back skin was gray in thetwo groups, mouse in the LFEMF group showed hair in vitro was evenly tiny hairs, and mouse in control group showed hair in vitro was uneven. At16days, hair length in the LFEMF group waslonger than the control group.2.At3days,at the bottom of hair follicle, we could see enlargedDP：matrix cells surrounded the dermal papilla and melanin above the dermal papilla in LFEMFgroup. We could rarely see those in control group. At9days,16days, compared with the controlgroup, the length of the hair follicle in LFEMF group significantly increased (P <0.05).3.TheIHC test of Ki67showed that: at3,9,16days, compared with the control group, the number ofKi67-positive cells in the low frequency electromagnetic field group were significantlyincreased(P<0.05); Ki67-positive cells mainly distributes in in the outer root sheath and theregion of the hair matrix cells.4.The IHC test of K15showed that:at3,9,16days, compared withthe control group, the number of K15-positive cells in the low frequency electromagnetic fieldgroup were significantly increased(P<0.05). At3days, K15-positive cells mainly distributes theskin base layer and the bulge of the hair follicle.At9,16days, K15-positive cells mainlydistributes in in the outer root sheath in control group and low frequency electromagnetic fieldgroup. The IF test of K15showed that: compared with the control group, K15-positive cells inthe low frequency electromagnetic field group were more.5.Real-time PCR and Western-blotshowed that expression of KGF was increased in the low-frequency electromagnetic field groupat3,9,16days; immunofluorescence showed that KGF is mainly distributes in the inner rootsheath and the region of the hair matrix cells.6.Real-time PCR showed that the expression ofβ-catenin was significantly increased in the low-frequency electromagnetic field group in3days,9days,16days(P<0.05).【Conclusion】 The result showed that the low frequency electromagnetic field promoted hairgrowth in C57BL/6mice. It may associate with the low frequency electromagnetic fieldspromote the expression of KGF and β-catenin, the proliferation of K15-positive cell, matrix cellsand cells of outer root sheath.