Hana Tuby

Induction of autologous mesenchymal stem cells in the bone marrow by low-level laser therapy has profound beneficial effects on the infarcted rat heart

The adult mammalian heart is known to have a very limited regenerative capacity following acute ischemia. In this study we investigated the hypothesis that photobiostimulation of autologous bone‐marrow‐derived mesenchymal stem cells (MSCs) by low‐level laser therapy (LLLT) applied to the bone marrow (BM), may migrate to the infarcted area and thus attenuate the scarring processes following myocardial infarction (MI).

Long-Term Safety of Low-Level Laser Therapy at Different Power Densities and Single or Multiple Applications to the Bone Marrow in Mice

OBJECTIVE The purpose of this study was to determine the long-term safety effect of low-level laser therapy (LLLT) to the bone marrow (BM) in mice. BACKGROUND DATA LLLT has been shown to have a photobiostimulatory effect on various cellular processes and on stem cells. It was recently shown that applying LLLT to BM in rats post-myocardial infarction caused a marked reduction of scar tissue formation in the heart. METHODS Eighty-three mice were divided into five groups: control sham-treated and laser-treated at measured density of either 4, 10, 18, or 40 mW/cm(2) at the BM level. The laser was applied to the exposed flat medial part of the tibia 8 mm from the knee joint for 100 sec. Mice were monitored for 8 months and then killed, and histopathology was performed on various organs. RESULTS No histological differences were observed in the liver, kidneys, brain or BM of the laser-treated mice as compared with the sham-treated, control mice. Moreover, no neoplasmic response in the tissues was observed in the laser-treated groups as compared with the control, sham-treated mice. There were no significant histopathological differences among the same organs under different laser treatment regimes in response to the BM-derived mesenchymal stem cell proliferation following LLLT to the BM. CONCLUSIONS LLLT applied multiple times either at the optimal dose (which induces photobiostimulation of stem cells in the BM), or at a higher dose (such as five times the optimal dose), does not cause histopathological changes or neoplasmic response in various organs in mice, as examined over a period of 8 months.

Autologous Bone-Marrow Stem Cells Stimulation Reverses Post-Ischemic-Reperfusion Kidney Injury in Rats

Background/Aims: 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 LLLT application to stem cells in the bone marrow (BM), on the kidneys of rats that had undergone acute ischemia-reperfusion injury (IRI). Methods: Injury to the kidneys was induced by the excision of the left kidney and 60 min of IRI to the right kidney in each rat. Rats were then divided randomly into 2 groups: non-laser-treated and laser-treated. LLLT was applied to the BM 10 min and 24 h post-IRI and rats were sacrificed 4 days post-IRI. Blood was collected before the sacrifice and the kidney processed for histology. Results: Histological evaluation of kidney sections revealed the restored structural integrity of the renal tubules, and a significant reduction of 66% of pathological score in the laser-treated rats as compared to the non-laser-treated ones. C-kit positive cell density in kidneys post-IRI and laser-treatment was (p = 0.05) 2.4-fold higher compared to that of the non-laser treated group. Creatinine, blood urea nitrogen, and cystatin-C levels were significantly 55, 48, and 25% lower respectively in the laser-treated rats as compared to non-treated ones. Conclusion: LLLT application to the BM causes induction of stem cells, which subsequently migrate and home in on the injured kidney. Consequently, a significant reduction in pathological features and improved kidney function post-IRI are evident. The results demonstrate a novel approach in cell-based therapy for acute ischemic injured kidneys. i 2014 S. Karger AG, Basel

Light Therapy for the Cardiovascular System

Coronary artery disease, which may lead to myocardial infarction (MI), is the primary cause of mortality world-wide. In a series of studies in which the rat and canine models were used, the effect of LLLT on infarct size after chronic myocardial infarction in rats was investigated. LLLT caused a profound (50–70%) reduction in infarct size and ventricular dilatation in the rat heart after chronic MI. This phenomenon was achieved by the cardioprotective effect of LLLT on mitochondria, elevation of cytoprotective heat shock proteins and enhanced angiogenesis in the myocardium following laser irradiation. The effect of LLLT on the expression of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) in the infarcted heart was also investigated. It was found that VGEF and iNOS expression in the infarcted rat heart is markedly upregulated by LLLT and is associated with enhanced angiogenesis and cardioprotection. The possible beneficial effects on implantation of autologeous mesenchymal stem cells (MSCs) that had been laser irradiated prior to their implantation into the infarcted rat heart was also investigated. These findings provided the first evidence that LLLT can significantly increase survival and/or proliferation of MSCs post implanation into the ischemic/ infarcted heart, followed by a marked reduction of scarring, and enhanced angio-genesis. The results of the animal studies may also have clinical relevance. It can be postulated that the use of laser following MI is most probably safe and our observations indicate that delivery of laser energy to the heart may have an important beneficial effect on patients after acute MI or ischemic heart conditions.