Low level light therapy (LLLT) significantly up‐regulated 11 proteins and down‐regulated two proteins in the dermal papilla (DP), offering a potential explanation of its mechanism of action in hair regrowth. Researchers Ratchathorn Panchaprateep MD, PhD, et al, obtained punch scalp biopsy specimens from male patients with androgenetic alopecia (AGA) before and after LLLT treatment. Subjects used an at-home, helmet-type LLLT device (655 nm, 5 mW) for 25 minutes every other day for 24 weeks.
The researchers performed liquid chromatography tandem mass spectrometry (LC‐MS/MS) analysis to identify proteins expressed in DP tissues from the biopsy specimens. The analysis revealed 11 statistically significant up‐regulated and 2 down‐regulated proteins in LLLT-treated DP compared with baseline. The most up-regulated protein was ATP‐binding cassette sub‐family G member, a transporter involved in cellular lipid homeostasis. Additionally, LLLT increased the main extracellular matrix (ECM) proteins in DP, which results in a greater volume of DP and a clinical improvement of hair diameter. Additional biological processes impacted by the up- and down-regulated proteins include cellular transcription, protein biosynthesis, cell energy, lipid homeostasis, ECM, ECM structural constituent, cell‐cell/cell‐matrix adhesion and angiogenesis.
The study was published in Lasers in Surgery and Medicine (September 2019).
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