In Vivo Low-level Light Therapy Increases Cytochrome Oxidase in Skeletal Muscle

Low-level light therapy (LLLT) increases survival of cultured cells, improves behavioral recovery from neurodegeneration and speeds wound healing. These beneficial effects are thought to be mediated by upregulation of mitochondrial proteins, especially the respiratory enzyme cytochrome oxidase. However, the effects of in vivo LLLT on cytochrome oxidase in intact skeletal muscle have not been previously investigated. We used a sensitive method for enzyme histochemistry of cytochrome oxidase to examine the rat temporalis muscle 24 h after in vivo LLLT. The findings showed for the first time that in vivo LLLT induced a dose- and fiber type-dependent increase in cytochrome oxidase in muscle fibers. LLLT was particularly effective at enhancing the aerobic capacity of intermediate and red fibers. The findings suggest that LLLT may enhance the oxidative energy metabolic capacity of different types of muscle fibers, and that LLLT may be used to enhance the aerobic potential of skeletal muscle.     

The ability of low level laser therapy to prevent muscle tissue damage induced by snake venom

Antivenom therapy has been ineffective in neutralizing the severe local fast developing tissue damage following snakebite envenoming. Herein, some effects of in situ helium neon (HeNe) laser irradiation on rat nerve-muscle preparation injected with Bothrops jararacussu venom are described. The tibialis anterior muscle was injected with venom diluted in 0.9% saline solution (60 microg/0.02 mL) or saline solution alone. Sixty minutes after venom injection, laser (HeNe) treatment was administered at three incident energy densities: dose 1, a single exposure of 3.5 J cm(-2); dose 2, three exposures of 3.5 J cm(-2); dose 3, a single exposure of 10.5 J cm(-2). Muscle function was assessed through twitch tension recordings whereas muscle damage was evaluated through histopathologic analysis, morphometry of area of tissue affected and creatine kinase (CK) serum levels, and compared to unirradiated muscles. Laser application at the dose of 3.5 J cm(-2) reduced the area of injury by 64% (15.9 +/- 1.5%vs 44.2 +/- 5.7%), decreased the neuromuscular blockade (NMB) by 62% (11.5 +/- 2.5%vs 30.4 +/- 5.2%) and reduced CK levels by 58% (from 455 +/- 4.5% to 190.3 +/- 23.4%) when compared with unirradiated controls. Dose 2 showed a poorer benefit than dose 1, and dose 3 was ineffective in preventing the venom effects. Measurements of the absorbance of unirradiated and irradiated venom solution showed no difference in absorption spectra. In addition, no difference in the intensity of partial NMB in nerve-muscle preparation was shown by unirradiated and irradiated venom. The results indicate that the laser light did not alter venom toxicity. We conclude that HeNe laser irradiation at a dosage of 3.5 J cm(-2) effectively reduces myonecrosis and the neuromuscular transmission blocking effect caused by B. jararacussu snake venom. Thus, low level laser therapy may be a promising tool to minimize the severity of some of the local effects of snake envenoming.     

Effects of 660‐nm and 780‐nm Laser Therapy on ST88‐14 Schwann Cells

The aim of the present study was to evaluate the comparative effects of red (660‐nm) and near‐infrared (780‐nm) low‐level laser therapy (LLLT) on viability, mitochondrial activity, morphology and gene expression of growth factors on Schwann cells (SC). ST88‐14 cells were grown in RPMI 1640 with 10 mM of HEPES, 2 mM of glutamine, 10% fetal bovine serum and 1% antibiotic‐antimycotic solution at 37°C in humidified atmosphere of 5% CO₂. Cells were detached with trypsin and centrifugated at 231 g for 5 min at 10°C, and the pellet (8 × 10⁴ cells/tube) was irradiated at the bottom of 50 ml polypropylene tube with a Twin‐Laser system (660 and 780 nm, 40 mW, 1 mW cm^?2, 3.2 and 6.4 J, 80 and 160 J cm^?2 with 80 and 160 s). After 1, 3 and 7 days, the analysis was performed. After irradiation, the SC increase mitochondrial activity, gene expression of the neural growth factors NGF and BDNF, and cell migration and increase the G2/M cells. SC showed neuronal morphology, normal F‐actin cytoskeleton organization and positive labeling for S100. PBM increased metabolic activity, mitosis and gene expression when irradiated with red and infrared LLLT. An increase in cell migration was obtained when irradiated with infrared LLLT.     

High Final Energy of Low‐Level Gallium Arsenide Laser Therapy Enhances Skeletal Muscle Recovery without a Positive Effect on Collagen Remodeling

The aim of this study was to evaluate the effects of a Gallium Arsenide (GaAs) laser, using a high final energy of 4.8 J, during muscle regeneration after cryoinjury. Thirty Wistar rats were divided into three groups: Control (C, n = 10); Injured (I, n = 10) and Injured and laser treated (Injured/LLLT, n = 10). The cryoinjury was induced in the central region of the tibialis anterior muscle (TA). The applications of the laser (904 nm, 50 mW average power) were initiated 24 h after injury, at energy density of 69 J cm^?1 for 48 s, for 5 days, to two points of the lesion. Twenty‐four hours after the final application, the TA muscle was removed and frozen in liquid nitrogen to assess the general muscle morphology and the gene expression of TNF‐α, TGF‐β, MyoD, and Myogenin. The Injured/LLLT group presented a higher number of regenerating fibers and fewer degenerating fibers (P < 0.05) without changes in the collagen remodeling. In addition, the Injured/LLLT group presented a significant decrease in the expression of TNF‐α and myogenin compared to the injured group (P < 0.05). The results suggest that the GaAs laser, using a high final energy after cryoinjury, promotes muscle recovery without changing the collagen remodeling in the muscle extracellular matrix.     

Mealworm Oil (MWO) Enhances Wound Healing Potential through the Activation of Fibroblast and Endothelial Cells

Mealworm and mealworm oil (MWO) have been reported to affect antioxidant, anti-coagulation, anti-adipogenic and anti-inflammatory activities. However, the function of MWO in wound healing is still unclear. In this study, we found that MWO induced the migration of fibroblast cells and mRNA expressions of wound healing factors such as alpha-smooth muscle actin (α-SMA), collagen-1 (COL-1) and vascular endothelial growth factor (VEGF) in fibroblast cells. The tube formation and migration of endothelial cells were promoted through the activation of VEGF/VEGF receptor-2 (VEGFR-2)-mediated downstream signals including AKT, extracellular signal-regulated kinase (ERK) and p38 by MWO-stimulated fibroblasts for angiogenesis. Moreover, we confirmed that MWO promoted skin wound repair by collagen synthesis, re-epithelialization and angiogenesis in an in vivo excisional wound model. These results demonstrate that MWO might have potential as a therapeutic agent for the treatment of skin wounds.     

Effects of flavonoid derivatives on human microvascular endothelial cells

Some natural compounds, including flavonoids, are active in vasculature re-growth during hair follicle disruption, but their effects have not been yet evaluated directly on microvascular endothelial cells. Skin vascularisation regulates the physiological blood supply required for hair growth and its dysregulation is the basis of several human diseases. Follicle-derived vascular endothelial growth factor (VEGF) release from follicular keratinocytes promotes perifollicular vascularisation and increases follicle and hair size, while blockade of VEGF-mediated angiogenesis leads to impaired hair growth. Here, we tested three flavonoids, namely visnadin (VSD), hesperidin (HSP) and baicalin (BC), on cultured human microvascular endothelial cells (HMEC), comparing their effects with minoxidil (MXD), a synthetic drug broadly used in the treatment of androgenetic alopecia. The response to these compounds was assayed in terms of endothelial survival, proliferation, tubulogenesis and proangiogenic signalling. We show that BC promotes HMEC proliferation, while both VSD and MXD enhance tubulogenesis. Interestingly, only HSP increases VEGFR-2 phosphorylation.     

Effect of low intensity helium-neon (HeNe) laser irradiation on experimental paracoccidioidomycotic wound healing dynamics

The effect of HeNe laser on the extracellular matrix deposition, chemokine expression and angiogenesis in experimental paracoccidioidomycotic lesions was investigated. At days 7, 8 and 9 postinfection the wound of each animal was treated with a 632.8 nm HeNe laser at a dose of 3 J cm(-2). At day 10 postinfection, the wounds were examined by using histologic and immunohistochemical methods. Results revealed that laser-treated lesions were lesser extensive than untreated ones, and composed mainly by macrophages and lymphocytes. High IL-1beta expression was shown in the untreated group whereas in laser-treated animals the expression was scarce. On the other hand, the expression of CXCL-10 was found to be reduced in untreated animals and quite intensive and well distributed in the laser-treated ones. Also, untreated lesions presented vascular endothelial growth factor (VEGF) in a small area near the center of the lesion and high immunoreactivity for hypoxia-inducible factor-1 (HIF-1), whereas laser-treated lesions expressed VEGF surrounding blood vessels and little immunoreactivity for HIF-1. Laser-treated lesions presented much more reticular fibers and collagen deposition when compared with the untreated lesion. Our results show that laser was efficient in minimizing the local effects observed in paracoccidioidomycosis and can be an efficient tool in the treatment of this infection, accelerating the healing process.     

Low‐Level Laser Therapy Restores the Oxidative Stress Balance in Acute Lung Injury Induced by Gut Ischemia and Reperfusion

It remains unknown if the oxidative stress can be regulated by low‐level laser therapy (LLLT) in lung inflammation induced by intestinal reperfusion (i‐I/R). A study was developed in which rats were irradiated (660 nm, 30 mW, 5.4 J) on the skin over the bronchus and euthanized 2 h after the initial of intestinal reperfusion. Lung edema and bronchoalveolar lavage fluid neutrophils were measured by the Evans blue extravasation and myeloperoxidase (MPO) activity respectively. Lung histology was used for analyzing the injury score. Reactive oxygen species (ROS) was measured by fluorescence. Both expression intercellular adhesion molecule 1 (ICAM‐1) and peroxisome proliferator‐activated receptor‐y (PPARy) were measured by RT‐PCR. The lung immunohistochemical localization of ICAM‐1 was visualized as a brown stain. Both lung HSP70 and glutathione protein were evaluated by ELISA. LLLT reduced neatly the edema, neutrophils influx, MPO activity and ICAM‐1 mRNA expression. LLLT also reduced the ROS formation and oppositely increased GSH concentration in lung from i‐I/R groups. Both HSP70 and PPARy expression also were elevated after laser irradiation. Results indicate that laser effect in attenuating the acute lung inflammation is driven to restore the balance between the pro‐ and antioxidants mediators rising of PPARy expression and consequently the HSP70 production.     

Cathepsin L derived from skeletal muscle cells transfected with bFGF promotes endothelial cell migration

Gene transfer of basic fibroblast growth factor (bFGF) has been shown to induce significant endothelial migration and angiogenesis in ischemic disease models. Here, we investigate what factors are secreted from skeletal muscle cells (SkMCs) transfected with bFGF gene and whether they participate in endothelial cell migration. We constructed replication-defective adenovirus vectors containing the human bFGF gene (Ad/bFGF) or a control LacZ gene (Ad/LacZ) and obtained conditioned media, bFGF-CM and LacZ-CM, from SkMCs infected by Ad/bFGF or Ad/LacZ, respectively. Cell migration significantly increased in HUVECs incubated with bFGF-CM compared to cells incubated with LacZ-CM. Interestingly, HUVEC migration in response to bFGF-CM was only partially blocked by the addition of bFGF-neutralizing antibody, suggesting that bFGF-CM contains other factors that stimulate endothelial cell migration. Several proteins, matrix metalloproteinase-1 (MMP-1), plasminogen activator inhibitor-1 (PAI-1), and cathepsin L, increased in bFGF-CM compared to LacZ-CM; based on 1-dimensional gel electrophoresis and mass spectrometry. Their increased mRNA and protein levels were confirmed by RT-PCR and immunoblot analysis. The recombinant human bFGF protein induced MMP-1, PAI-1, and cathepsin L expression in SkMCs. Endothelial cell migration was reduced in groups treated with bFGF-CM containing neutralizing antibodies against MMP-1 or PAI-1. In particular, HUVECs treated with bFGF-CM containing cell-impermeable cathepsin L inhibitor showed the most significant decrease in cell migration. Cathepsin L protein directly promotes endothelial cell migration through the JNK pathway. These results indicate that cathepsin L released from SkMCs transfected with the bFGF gene can promote endothelial cell migration.     

Infrared (810 nm) low-level laser therapy in experimental model of strain-induced skeletal muscle injury in rats: effects on functional outcomes

Muscle strains are among the most prevalent causes for athletes' absence from sport activities. Low-level laser therapy (LLLT) has recently emerged as a potential contender to nonsteroidal anti-inflammatory drugs in muscle strain treatment. In this work we investigated effects of LLLT and diclofenac on functional outcomes in the acute stage after muscle strain injury in rats. Muscle strain was induced by overloading the tibialis anterior muscle of rats during anesthesia. The injured groups received either no treatment, or a single treatment with diclofenac 30 min prior to injury, or LLLT (810 nm, 100 mW) with doses of 1, 3, 6 or 9 J, at 1 h after injury. Functional outcome measures included a walking index and assessment of electrically induced muscle performance. All treatments (except 9 J LLLT) significantly improved the walking index 12 h postinjury compared with the untreated group. The 3 J group also showed a significantly better walking index than the drug group. All treatments significantly improved muscle performance at 6 and 12 h. LLLT dose of 3 J was as effective as the pharmacological agent in improving functional outcomes in the early phase after a muscle strain injury in rats.     

Low‐Level Laser Therapy and Sodium Diclofenac in Acute Inflammatory Response Induced by Skeletal Muscle Trauma: Effects in Muscle Morphology and mRNA Gene Expression of Inflammatory Markers

Pharmacological therapy is widely used in the treatment of muscle injuries. On the other hand, low‐level laser therapy (LLLT) arises as a promising nonpharmacological treatment. The aim of this study was to analyze the effects of sodium diclofenac (topical application) and LLLT on morphological aspects and gene expression of biochemical inflammatory markers. We performed a single trauma in tibialis anterior muscle of rats. After 1 h, animals were treated with sodium diclofenac (11.6 mg g^‐1 of solution) or LLLT (810 nm; continuous mode; 100 mW; 3.57 W cm^?2; 1, 3 or 9 J; 10, 30 or 90 s). Histological analysis and quantification of gene expression (real‐time polymerase chain reaction—RT‐PCR) of cyclooxygenase 1 and 2 (COX‐1 and COX‐2) and tumor necrosis factor‐alpha (TNF‐α) were performed at 6, 12 and 24 h after trauma. LLLT with all doses improved morphological aspects of muscle tissue, showing better results than injury and diclofenac groups. All LLLT doses also decreased (P < 0.05) COX‐2 compared to injury group at all time points, and to diclofenac group at 24 h after trauma. In addition, LLLT decreased (P < 0.05) TNF‐α compared both to injury and diclofenac groups at all time points. LLLT mainly with dose of 9 J is better than topical application of diclofenac in acute inflammation after muscle trauma.     

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

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 that 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 cm^?2, 30 J cm^?2) for 10 min per 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 2 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.     

Low Level Light Therapy Modulates Inflammatory Mediators Secreted by Human Annulus Fibrosus Cells during Intervertebral Disc Degeneration In Vitro

Intervertebral disc degeneration (IVD) is one of the important causes of low back pain and is associated with inflammation induced by interaction between macrophages and the human annulus fibrosus (AF) cells. Low‐level light therapy (LLLT) has been widely known to regulate inflammatory reaction. However, the effect of LLLT on macrophage‐mediated inflammation in the AF cells has not been studied till date. The aim of this study is to mimic the inflammatory microenvironment and to investigate the anti‐inflammatory effect of LLLT at a range of wavelengths (405, 532 and 650 nm) on the AF treated with macrophage‐like THP‐1 cells conditioned medium (MCM) containing proinflammatory cytokines and chemokines (interleukin‐1beta, tumor necrosis factor‐alpha, interleukin‐6 and 8). We observed that AF cells exposed to MCM secrete significantly higher concentrations of IL‐6, IL‐8, IL‐1β and TNF‐α. LLLT markedly inhibited secretion of IL‐6 at 405 nm in a time‐dependent manner. Level of IL‐8 was significantly decreased at all wavelengths in a time‐dependent manner. We showed that MCM can induce the inflammatory microenvironment in AF cells and LLLT selectively suppressed IL‐6 and 8 levels. The results indicate that LLLT is a potential method of IVD treatment and provide insights into further investigation of its anti‐inflammation effect on IVD.     

Bee (Apis mellifera) venom produced toxic effects of higher amplitude in rat thoracic aorta than in skeletal muscle--an ultrastructural study

In this study, changes produced in aorta and triceps surae muscle of Wistar rats as response to bee venom (BV) envenomation were analyzed by transmission electron microscopy and morphometry. A subchronic treatment of 30 days with daily doses of 700 μg BV/kg and an acute-lethal treatment with a single dose of 62 mg BV/kg were performed. The subchronic treatment resulted in endothelial cell retraction, a thicker subendothelial layer, and thinner elastic laminae and musculoelastic layers in aorta, and thicker endothelium and basal laminae in skeletal muscle. In both tissues polymorphous, swollen mitochondria with disrupted cristae were observed. The acute treatment produced extensive endothelial lesions, breakdown of the collagen layer and migration of muscle cells toward the intima in the aorta, and dilatation of endoplasmic reticulum in the skeletal muscle cells. Mitochondria were almost devoid of cristae or with few circular cristae in the smooth muscle cells while most of the mitochondria presented abnormal circular cristae in the skeletal muscle cells. Degenerative alterations in the aorta were of higher intensity in our experiments-both the intima and media strongly responded to BV, in contrast to those found at the level of the skeletal muscle cells where a moderate degenerative myopathy was recorded.     

Flow goes forward and cells step backward: endothelial migration

Systemic and pulmonary circulations constitute a complex organ that serves multiple important biological functions. Consequently, any pathological processing affecting the vasculature can have profound systemic ramifications. Endothelial and smooth muscle are the two principal cell types composing blood vessels. Critically, endothelial proliferation and migration are central to the formation and expansion of the vasculature both during embryonic development and in adult tissues. Endothelial populations are quite heterogeneous and are both vasculature type- and organ-specific. There are profound molecular, functional, and phenotypic differences between arterial, venular and capillary endothelial cells and endothelial cells in different organs. Given this endothelial cell population diversity, it has been challenging to determine the origin of endothelial cells responsible for the angiogenic expansion of the vasculature. Recent technical advances, such as precise cell fate mapping, time-lapse imaging, genome editing, and single-cell RNA sequencing, have shed new light on the role of venous endothelial cells in angiogenesis under both normal and pathological conditions. Emerging data indicate that venous endothelial cells are unique in their ability to serve as the primary source of endothelial cellular mass during both developmental and pathological angiogenesis. Here, we review recent studies that have improved our understanding of angiogenesis and suggest an updated model of this process.Subject terms: Cell lineage, Chemotaxis     

In vivo study of the inflammatory modulating effects of low-level laser therapy on iNOS expression using bioluminescence imaging

This study was designed to demonstrate that bioluminescence imaging (BLI) can be used as a new tool to evaluate the effects of low-level laser therapy (LLLT) during in vivo inflammatory process. Here, the efficacy of LLLT in modulating inducible nitric oxide synthase (iNOS) expression using different therapeutic wavelengths was determined using transgenic animals with the luciferase gene under control of the iNOS gene expression. Thirty transgenic mice, FVB/N-Tg(iNOS-luc)Xen, were allocated randomly to one of four experimental groups treated with different wavelengths (lambda = 635, 785, 808 and 905 nm) or a control group (nontreated). Inflammation was induced by intra-articular injection of zymosan A in both knee joints. Laser treatment (25 mW cm(-2), 200 s, 5 J cm(-2)) was applied to the knees 15 min after inflammation induction. Measurements of iNOS expression were performed at various times (0, 3, 5, 7, 9 and 24 h) by measuring the bioluminescence signal using a highly sensitive charge-coupled device (CCD) camera. The results showed a significant increase in BLI signal after irradiation with 635 nm laser when compared to the nonirradiated animals and the other LLLT-treated groups, indicating wavelength dependence of LLLT effects on iNOS expression during the inflammatory process, and thus demonstrating an action spectrum of iNOS gene expression following LLLT in vivo that can be detected by BLI. Histological analysis was also performed and demonstrated the presence of fewer inflammatory cells in the synovial joints of mice irradiated with 635 nm compared with nonirradiated knee joints.     

Effects of Photobiomodulation on Functionality in Wistar Rats with Sciatic Nerve Injury

A peripheral nerve injury (PNI) can result in motor or sensory disorders. Low‐level laser therapy (LLLT) has demonstrated positive results as a treatment option for PNI. Wistar rats were divided into five groups: Control, Injury, Injury + LLLTn (nerve), Injury + LLLTm (muscle) and Injury + LLLTn + m (nerve and muscle irradiation). The groups were analyzed after one, two, three and four weeks. PNI was achieved by crushing the sciatic nerve. Laser treatment (780 nm, 3.2 J) was realized over the nerve and/or tibialis anterior muscle. In gait analyses, the groups irradiated over the nerve demonstrated an improvement after two weeks. In the analysis of mechanical sensitivity, the Injury + LLLTn demonstrated a reduction after one week in comparison with Injury group; the Injury + LLLTn + m and Injury + LLLTm demonstrated an increase after two weeks in comparison with Injury group; and the irradiated groups demonstrated a reduction in nociception after four weeks in comparison with Injury group. In the analysis of muscle atrophy, the Injury + LLLTn demonstrated more muscle mass after two weeks. LLLT improves functional aspects related to gait, mechanical sensitivity and muscle mass, with better results regarding motor aspects and muscle mass when administered over the injured nerve and better results regarding sensory aspects when administered over the muscle.     

The discovery of placenta growth factor and its biological activity

Angiogenesis is a complex biological phenomenon crucial for a correct embryonic development and for post-natal growth. In adult life, it is a tightly regulated process confined to the uterus and ovary during the different phases of the menstrual cycle and to the heart and skeletal muscles after prolonged and sustained physical exercise. Conversly, angiogenesis is one of the major pathological changes associated with several complex diseases like cancer, atherosclerosis, arthritis, diabetic retinopathy and age-related macular degeneration. Among the several molecular players involved in angiogenesis, some members of VEGF family, VEGF-A, VEGF-B and placenta growth factor (PlGF), and the related receptors VEGF receptor 1 (VEGFR-1, also known as Flt-1) and VEGF receptor 2 (VEGFR-2, also known as Flk-1 in mice and KDR in human) have a decisive role. In this review, we describe the discovery and molecular characteristics of PlGF, and discuss the biological role of this growth factor in physiological and pathological conditions.     

Anti-inflammatory effects of low-level laser therapy (LLLT) with two different red wavelengths (660 nm and 684 nm) in carrageenan-induced rat paw edema

It has been suggested that low-level laser therapy (LLLT) can modulate inflammatory processes. The aim of this experiment was to investigate what effects red laser irradiation with two different wavelengths (660 nm and 684 nm) on carrageenan-induced rat paw edema and histology. Thirty two male Wistar rats were randomly divided into four groups. One group received a sterile saline injection, while inflammation was induced by a sub-plantar injection of carrageenan (1 mg/paw) in the three other groups. After 1 h, LLLT was administered to the paw in two of the carrageenan-injected groups. Continuous wave 660 nm and 684 nm red lasers respectively with mean optical outputs of 30 mW and doses of 7.5 J/cm(2) were used. The 660 nm and 684 nm laser groups developed significantly (p<0.01) less edema (0.58 ml [SE+/-0.17] ml and 0.76 ml [SE+/-0.10] respectively) than the control group (1.67 ml [SE+/-0.19]) at 4h after injections. Similarly, both laser groups showed a significantly lower number of inflammatory cells in the muscular and conjunctive sub-plantar tissues than the control group. We conclude that both 660 nm and 684 nm red wavelengths of LLLT are effective in reducing edema formation and inflammatory cell migration when a dose of 7.5 J/cm(2) is used.     

Vibrio vulnificus cytolysin induces hyperadhesiveness of pulmonary endothelial cells for neutrophils through endothelial P-selectin: a mechanism for pulmonary damage by Vibrio vulnificus cytolysin

Vibrio vulnificus cytolysin forms transmembrane pores that are permeable to calcium ions in pulmonary endothelial cells, and has been suggested as an important virulence factor that sequestrate neutrophils primarily in the lung. To elucidate the mechanism we investigated whether the cytolysin affect the expression of endothelial P-selectin and adhesiveness of pulmonary endothelial cells for neutrophils. The cytolysin increased the adhesiveness of CPAE cell, a pulmonary endothelial cell line, for neutrophils in a concentration- and time-dependent manner. The increase of adhesiveness occurred within several minutes after the cytolysin exposure, persisted up to 90 min, and was not affected by cycloheximide. Furthermore, flow cytometric analyses showed that cytolysin enhanced the level of P-selectin on CPAE cell surface. Therefore, these results suggest that the cytolysin-induced hyperadhesiveness of pulmonary endothelial cells for neutrophils is mediated by the mobilization of endothelial P-selectin to the cell surface.