Laser Stimulation of Stem Cells Repairs Kidney and Liver Damage – Sheds Light on How Laser Therapy Heals


Stem cells stimulated with laser irradiation can do more than just reduce scar tissue in rat hearts after heart attack (Tuby, H. et al, 2011); additional studies show that stem cells can rejuvenate rat liver and rat kidney, and even migrate from bone marrow to the ischemia-reperfusion injury in the kidney resulting in improved organ function. Is this proof-of-concept for an underlying mechanism by which laser therapy, used to relieve pain in the lower back, knees or joints, could be repairing bone or muscle tissue?

Laser stimulation of stem cells, tissue regeneration, tissue repair

Rat Kidney
(photo by M. Bahe)

In a 2014 study reported in the Journal of Biomedical Science and Engineering, researchers sought to investigate the potential benefits of laser stimulated stem cells in a rat model of renal failure since there are few treatment options currently available for this life-threatening disease. They induced an ischemia-reperfusion injury in the kidneys of rats and then evaluated the effect of laser therapy applied to the bone marrow. Results showed restoration of renal tubules and reduced necrosis in the laser-treated rats as compared to the control group. Researchers concluded that the laser stimulation of the bone marrow caused an increase in the density of mesenchymal stem cells in the kidneys and thus an increase in kidney function.

In a 2010 study conducted at Tel-Aviv University, Professor Uri Oron and his team applied laser irradiation to stem cells in 12 rats that had undergone removal of 70% of their livers for experimental purposes. Results showed a significant increase in the number of proliferating (stem) cells in the regenerating parts of the laser-treated livers compared to the non-treated livers. Furthermore, researchers observed an increase in density of newly formed blood vessels. Did these new blood vessels contribute to tissue repair and healing? Wound healing is similarly marked by the formation of granulation tissue complete with tiny capillaries and new connective tissue.

Patients suffering from diseases that either threaten life or limit its quality are anxious to see more clinical studies like these advance to human trials in order to prove the efficacy of new treatments like laser stimulation of bone marrow.

Induction of Autologous Bone-Marrow Stem Cells by Low-Level Laser Therapy Has Beneficial Effects on the Kidneys Post-Ischemia-Reperfusion Injury in the Rat

Authors: Hana Tuby, Lidya Maltz, Uri Oron

Citation: Journal of Biomedical Science and Engineering (2014), 7, 453-463. doi: 10.4236/jbise.2014.78048.

Acute renal failure has a 50% – 80% mortality rate. Currently, treatment options for this life-threatening disease are limited. Low-level laser therapy (LLLT) has been found to modulate biological activity. The aim of the present study was to investigate the possible beneficial effects of laser application to stem cells in the bone marrow, on the kidneys of rats that had undergone ischemia-reperfusion injury (IRI). IRI was induced by occlusion of the renal artery to 3- and 7-month-old rats for 15 or 30 minutes. In an additional experiment IRI was applied to both kidneys for 20 min each in 2-3-month-old rats. Rats were then divided randomly into two groups of control and laser-treated. Laser therapy (Ga-Al-As 810 nm, 200 mW output for 2 min) was applied to the bone marrow 1 and 7 days post-IRI to the kidneys, and rats were sacrificed 2 weeks later. Histomorphometry and immunohistochemistry were performed on kidney sections and blood markers for kidney function. Quantitative histomorphometric analysis revealed a reduction in dilatation of the renal tubules, restored structural integrity of the renal tubules, and reduced necrosis in the laser-treated rats as compared to the control, non-laser-irradiated group. C-kit positive cell density in kidneys post-IRI and laser-treatment was significantly (p = 0.015) 3.2-fold higher compared to the control group. Creatinine and blood urea nitrogen content were significantly lower in the laser-treated rats as compared to control. It is concluded that LLLT application to the bone marrow (BM) causes a significant increase in the density of mesenchymal stem cells in the kidneys post-IRI, probably by induction of stem cells in the BM, which subsequently migrate to the IRI kidney, significantly reducing the pathological features of the kidney and increasing kidney function post IRI.

Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.

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Enhanced liver regeneration following acute hepatectomy by low-level laser therapy

Authors: Oron U1, Maltz L, Tuby H, Sorin V, Czerniak A.

Citation: Photomed Laser Surg. 2010 Oct;28(5):675-8. doi: 10.1089/pho.2009.2756. Epub 2010 Oct 9.

The aim of the present study was to investigate the effect of low-level laser therapy (LLLT) on liver regeneration following hepatectomy.

LLLT has been found to modulate various biological processes.

Twelve mature male rats were used. The liver was exposed, and 70% of it was excised. The rats were assigned randomly to two groups: control, non-laser treated, and experimental, laser-treated (diode [Ga-Al-As] laser 804 nm) group. For determination of newly formed blood vessels and proliferating cells, 5-Bromo-2’deoxyuridine (BrdU) was injected intraperitoneally. The rats were sacrificed 2 d post hepatectomy, and histological sections from each liver were processed for analysis of new blood-vessel formation using BrdU immunostaining kit. Mesenchymal stem cells (MSCs) were assessed using c-kit immunostaining. BrdU-labeled cells were counted as for estimation of newly formed hepatic cells.

It was found that the number of proliferating cells (BrdU positive cells) per area in the regenerating regions of the livers were significantly (p < 0.01) 2.6-fold higher in the laser-treated rats than in the control non-laser-treated rats. The density of the newly formed blood vessels and c-kit immunopositive cells in the regenerating area of the laser-treated livers was significantly (p < 0.01) 3.3- and 2.3-fold respectively higher than the control non-laser treated livers.

It is concluded that LLLT following acute hepatectomy most probably stimulates a significant enhancement of liver regeneration conducive to both the formation of new hepatocytes and MSCs and angiogenesis in the regenerating liver.

Author information
1 Department of Zoology, Life Sciences Faculty, Tel-Aviv University, Tel-Aviv, Israel.