Transient Repetitive Exposure to Low Level Light Therapy Enhances Collateral Blood Vessel Growth in The Ischemic Hindlimb of The Tight Skin Mouse

Abstract

The tight skin mouse (Tsk−/+) is a model of scleroderma characterized by impaired vasoreactivity, increased oxidative stress, attenuated angiogenic response to VEGF, and production of the angiogenesis inhibitor angiostatin. Low level light therapy (LLLT) stimulates angiogenesis in myocardial infarction and chemotherapy-induced mucositis. We hypothesize repetitive LLLT restores vessel growth in the ischemic hindlimb of Tsk−/+ mice by attenuating angiostatin and enhancing angiomotin effects in vivo. C57Bl/6J and Tsk−/+ mice underwent ligation of the femoral artery. Relative blood flow to the foot was measured using a laser Doppler imager. Tsk−/+ mice received LLLT (670 nm, 50 mW cm2, 30 J/cm2) for 10 min/day for 14 days. Vascular density was determined using lycopersicom lectin staining. Immunofluorescent labeling, western blot analysis, and immunoprecipitation were used to determine angiostatin and angiomotin expression. Recovery of blood flow to the ischemic limb was reduced in Tsk−/+ compared with C57Bl/6 mice two weeks after surgery. LLLT treatment of Tsk−/+ mice restored blood flow to levels observed in C57Bl/6 mice. Vascular density was decreased, angiostatin expression was enhanced and angiomotin depressed in the ischemic hindlimb of Tsk−/+ mice. LLLT treatment reversed these abnormalities. LLLT stimulates angiogenesis by increasing angiomotin and decreasing angiostatin expression in the ischemic hindlimb of Tsk−/+ mice.

Which wavelength is optimal for transcranial low‐level laser stimulation?

“…Photobiomodulation employs high influence but low power light from light emitting diode (LED) system or laser sources in wavelength range from 600 to 1000 nm, to modulate mitochondrial respiration in a nonthermal and noninvasive way . Transcranial low‐level laser stimulation of the brain with light at near‐infrared range is a novel form of photobiomodulation, which is well known as low‐level light/laser therapy/treatment (LLLT) on patients .…”

Effect of the transdermal low-level laser therapy on endothelial function

“…A 14-day exposure to laser radiation contributed to the formation of collateral circulation in the limbs, which were previously hypoxic [20]. In the available literature, there were no more data regarding the relationship between LLLT and the level of angiostatin.…”

Animal Models of Systemic Sclerosis

“…Indeed, D-4F improved vascular function, decreased myocardial inflammation, and restored angiogenic potential in the hearts of Tsk/+ mice [77]. Second, transient repetitive exposure to low level light therapy stimulated angiogenesis and collateral blood vessel growth by increasing angiomotin and decreasing angiostatin expression in Tsk/+ [78].…”