Helium-neon laser irradiation stimulates migration and proliferation in melanocytes and induces repigmentation in segmental-type vitiligo

Tailoring photobiomodulation to enhance tissue regeneration

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

Phototherapy for vitiligo: A narrative review on the clinical and molecular aspects, and recent literature

BACKGROUND

Vitiligo is characterized by depigmented patches resulting from loss of melanocytes. Phototherapy has emerged as a prominent treatment option for vitiligo, utilizing various light modalities to induce disease stability and repigmentation.

AIMS AND METHODS

This narrative review aims to explore the clinical applications and molecular mechanisms of phototherapy in vitiligo.

RESULTS AND DISCUSSION

The review evaluates existing literature on phototherapy for vitiligo, analyzing studies on hospital-based and home-based phototherapy, as well as outcomes related to stabilization and repigmentation. Narrowband ultra-violet B, that is, NBUVB remains the most commonly employed, studied and effective phototherapy modality for vitiligo. Special attention is given to assessing different types of lamps, dosimetry, published guidelines, and the utilization of targeted phototherapy modalities. Additionally, the integration of phototherapy with other treatment modalities, including its use as a depigmenting therapy in generalized/universal vitiligo, is discussed. Screening for anti-nuclear antibodies and tailoring approaches for non-photo-adapters are also examined.

CONCLUSION

In conclusion, this review provides a comprehensive overview of phototherapy for vitiligo treatment. It underscores the evolving landscape of phototherapy and offers insights into optimizing therapeutic outcomes and addressing the challenges ahead. By integrating clinical evidence with molecular understanding, phototherapy emerges as a valuable therapeutic option for managing vitiligo, with potential for further advancements in the field.

Comparative efficacy of 2% minoxidil alone against combination of 2% minoxidil and low-level laser therapy in female pattern hair loss-A randomized controlled trial in Chinese females

OBJECTIVES

To investigate the effectiveness and safety of combination of 655 nm low level laser helmet device with topical 2 % minoxidil solution at FPHL in Chinese population.

MATERIALS AND METHODS

Randomized, parallel, controlled, single-blind clinical trial was conducted. FPHL subjects were randomly allocated into 2 % minoxidil group and combination group. The 2 % minoxidil group received 1 ml topical 2 % minoxidil solution twice daily for 24 weeks. The combination group received 1 ml topical 2 % minoxidil solution twice daily together with 20 min 655 nm low-level laser helmet once every other day for 24 weeks. Hair parameters in two scalp areas including midscalp and vertex were evaluated at baseline, 12th week and 24th week.

RESULTS

In midscalp area, the combination group showed a lower increase in intermediate hair percentage than 2 % minoxidil group, which was statistically significant. Besides, the combination group had statistically significant increase than 2 % minoxidil group in mean hair diameter. Reported relative adverse events included slightly hair loss (27.8 %), desquamation (19.0 %), pruritus (15.2 %), seborrhea (2.5 %) and hypertrichosis (2.5 %).

CONCLUSION

In our trial, LLLT was demonstrated as a useful supplementary treatment for FPHL and the combination with 2 % minoxidil accomplished better improvement in intermediate hair enlargement and hair diameter of midscalp for FPHL.

A focused review of visible light therapies for vitiligo

BACKGROUND

Vitiligo can be challenging to treat and exhibit an unpredictable clinical course. Phototherapy in the form of visible light can achieve both repigmentation and depigmentation outcomes in vitiligo, with minimal associated adverse events. This review focuses on the mechanistic understandings and clinical outcomes of visible light-based treatments for vitiligo.

METHODS

Articles were retrieved from PubMed starting from May 1965 until August 2023, yielding 496 unique articles. We conducted title, abstract, and full-text screening to identify articles describing the use of visible light (380-750 nm), either as part of combination therapy or as monotherapy, for repigmentation or depigmentation treatment in vitiligo.

RESULTS

Twenty-seven articles met inclusion criteria, offering preclinical and clinical data regarding the utilization of helium-neon laser (red light) and blue light-emitting diodes (LEDs) as methods of repigmentation therapy in vitiligo. Preclinical and clinical data on the utilization of Q-switched ruby laser (694 nm) and frequency-doubled (FD) Nd:YAG laser (532 nm) for vitiligo depigmentation therapy were also identified.

CONCLUSION

While limited by small studies and a lack of standardized administration of phototherapy, the evidence for visible light's effectiveness in managing vitiligo is encouraging. Red light therapy using He-Ne lasers and blue light therapy via LEDs can stimulate repigmentation in patients with vitiligo with minimal adverse events. Q-switched ruby and FD Nd:YAG lasers provide viable, visible light depigmentation options, either alone or with topical agents. With limited clinical data, larger studies are needed to validate the efficacy of visible light therapy in treating vitiligo and to better understand its long-term outcomes.

Photobiomodulation for melasma treatment: Integrative review and state of the art

PURPOSE

Photobiomodulation therapy (PBM) is a versatile technique for treating skin diseases. Melasma, a chronic hyperpigmentation condition, has recently been associated with vascular features and dermal photoaging and poses significant management challenges. We review the recent literature on melasma etiology and the evidence supporting PBM as a therapeutic modality for melasma treatment.

METHODS

We conducted a comprehensive literature search in three different databases from May to August 2023, focusing on studies published in the past 10 years. The inclusion criteria comprised full-text studies investigating low-power lasers and/or light-emitting diodes (LEDs) in in vitro or in vivo models, as well as clinical trials. We excluded studies discussing alternative melasma therapies or lacking experimental data. We identified additional studies by searching the reference lists of the selected articles.

RESULTS

We identified nine relevant studies. Clinical studies, in agreement with in vitro experiments and animal models, suggest that PBM effectively reduces melasma-associated hyperpigmentation. Specific wavelengths (red: 630 nm; amber: 585 and 590 nm; infrared: 830 and 850 nm) at radiant exposures between 1 and 20 J/cm2 exert modulatory effects on tyrosinase activity, gene expression, and protein synthesis of melanocytic pathway components, and thus significantly reduce the melanin content. Additionally, PBM is effective in improving the dermal structure and reducing erythema and neovascularization, features recently identified as pathological components of melasma.

CONCLUSION

PBM emerges as a promising, contemporary, and non-invasive procedure for treating melasma. Beyond its role in inhibiting melanogenesis, PBM shows potential in reducing erythema and vascularization and improving dermal conditions. However, robust and well-designed clinical trials are needed to determine optimal light parameters and to evaluate the effects of PBM on melasma thoroughly.

Electromechanical therapy in diabetic foot ulcers patients: A systematic review and meta-analysis

Purpose

Diabetic foot ulcer (DFU) is one of the most devastating and troublesome consequences of diabetes. The current therapies are not always effective because of the complicated aetiology and interactions of local and systemic components in DFU. However, adjunctive therapy (electromechanical therapy) has become the latest modality in recent years, although there is a lack of significant research to support its utilization as a treatment standard. The purpose of this systematic research was to review the literature on the application of electromechanical therapies in the healing of DFUs.

Methods

For this systematic review, we searched PubMed, Medline, EmBase, the Cochrane library, and Google Scholar for the most current research (1990-2022) on electromechanical therapies for DFUs. We used the PICO method (where P is population, I is intervention, C is comparator/control, and O is outcome for our study) to establish research question with the terms [Electromechanical therapy OR Laser therapy OR photo therapy OR Ultrasound therapy OR Shockwave therapy] AND [diabetic foot ulcers OR diabetes] were used as search criteria. Searches were restricted to English language articles only. Whereas, Cochrane handbook of "Systematic Reviews of Interventions" with critical appraisal for medical and health sciences checklist for systematic review was used for risk of bias assessment. There were 39 publications in this study that were deemed to be acceptable. All the suitably selected studies include 1779 patients.

Results

The meta-analysis of 15 included research articles showed the overall effect was significant (P = 0.0002) thus supporting experimental groups have improvement in the DFUs healing in comparison to the control group.

Conclusion

This systematic review and meta-analysis revealed electromechanical treatments are significantly viable options for patients with DFUs. Electromechanical therapy can considerably reduce treatment ineffectiveness, accelerate healing, and minimize the time it takes for complete ulcer healing.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01240-2.

Wearable Surface-Lighting Micro-Light-Emitting Diode Patch for Melanogenesis Inhibition

Wearable light-emitting diode (LED)-based phototherapeutic devices have recently attracted attention as skin care tools for wrinkles, acne, and hyperpigmentation. However, the therapeutic effectiveness and safety of LED stimulators are still controversial due to their inefficient light transfer, high heat generation, and non-uniform spot irradiation. Here, a wearable surface-lighting micro-LED (SµLED) photostimulator is reported for skin care and cosmetic applications. The SµLEDs, consisting of a light diffusion layer (LDL), 900 thin film µLEDs, and polydimethylsiloxane (PDMS), achieve uniform surface-lighting in 2 × 2 cm² -sized area with 100% emission yields. The SµLEDs maximize photostimulation effectiveness on the skin surface by uniform irradiation, high flexibility, and thermal stability. The SµLED's effect on melanogenesis inhibition is evaluated via in vitro and in vivo experiments to human skin equivalents (HSEs) and mouse dorsal skin, respectively. The anti-melanogenic effect of SµLEDs is confirmed by significantly reduced levels of melanin contents, melan-A, tyrosinase, and microphthalmia-associated transcription factor (MITF), compared to a conventional LED (CLED) stimulator.

Femtosecond laser attenuates oxidative stress, inflammation, and liver fibrosis in rats: Possible role of PPARγ and Nrf2/HO-1 signaling

Liver fibrosis is the excessive accumulation of extracellular matrix (ECM) proteins that occurs in chronic liver injury. Inflammation and oxidative stress play a key role in fibrogenesis which can develop into cirrhosis and carcinoma. Low-level laser therapy (LLLT) has promising therapeutic effects against fibrogenesis; however, the specific underlying mechanism is not fully elucidated. We investigated the potential of LLLT to attenuate carbon tetrachloride (CCl₄)-induced liver fibrosis in rats, focusing on oxidative injury, inflammatory response, and the possible role of PPARγ and Nrf2/HO-1 signaling. Rats were given CCl₄ and exposed to LLLT twice/week for 6 weeks and blood and liver samples were collected for analysis. CCl₄ caused liver injury and fibrosis manifested by hepatocyte injury, steatosis, inflammatory cell infiltration, and accumulation of collagen, elevated serum transaminases and bilirubin, and decreased albumin. ROS, MDA, NO, NF-κB p65, TNF-α, iNOS, TGF-β1, and IL-6 were increased in the liver of CCl₄-administered rats. Exposure to LLLT ameliorated histopathological alterations, collagen deposition, and liver function markers, and downregulated hepatic α-SMA, collagen 1A1, and collagen 3A1. In Addition, LLLT decreased ROS, MDA, NO, NF-κB p65, TGF-β1, and pro-inflammatory mediators, and enhanced antioxidant defenses. These effects were associated with upregulated PPARγ, Nrf2, and HO-1, both gene and protein expression. In conclusion, LLLT attenuated liver fibrosis by suppressing ECM production and deposition, oxidative injury and inflammation, and upregulating PPARγ and Nrf2/HO-1 signaling.

Laser Photobiomodulation 808 nm: Effects on Gene Expression in Inflammatory and Osteogenic Biomarkers in Human Dental Pulp Stem Cells

The tissue engineering of dental oral tissue is tackling significant advances and the use of stem cells promises to boost the therapeutical approaches of regenerative dentistry. Despite advances in this field, the literature is still scarce regarding the modulatory effect of laser photobiomodulation (PBM) on genes related to inflammation and osteogenesis in Postnatal Human Dental Pulp Stem cells (DPSCs). This study pointedly investigated the effect of PBM treatment in proliferation, growth and differentiation factors, mineralization, and extracellular matrix remodeling genes in DPSCs. Freshly extracted human third molars were used as a source for DPSCs isolation. The isolated DPSCs were stimulated to an inflammatory state, using a lipopolysaccharide (LPS) model, and then subjected or not to laser PBM. Each experiment was statistically evaluated according to the sample distribution. A total of 85 genes related to inflammation and osteogenesis were evaluated regarding their expression by RT-PCR. Laser PBM therapy has shown to modulate several genes expression in DPSCs. PBM suppressed the expression of inflammatory gene TNF and RANKL and downregulated the gene expression for VDR and proteolytic enzymes cathepsin K, MMP-8 and MMP-9. Modulation of gene expression for proteinase-activated receptors (PARs) following PBM varied among different PARs. As expected, PBM blocked the odontoblastic differentiation of DPSCs when subjected to LPS model. Conversely, PBM has preserved the odontogenic potential of DPSCs by increasing the expression of TWIST-1/RUNEX-2/ALP signaling axis. PBM therapy notably played a role in the DPSCs genes expression that mediate inflammation process and tissue mineralization. The present data opens a new perspective for PBM therapy in mineralized dental tissue physiology.

Synergistic effect of photobiomodulation and phthalocyanine photosensitizer on fibroblast signaling responses in an in vitro three-dimensional microenvironment

Photobiomodulation (PBM) is a promising medical treatment modality in the area of photodynamic therapy (PDT). In this study, we investigated the effect of combined therapy in a 3D microenvironment using aluminum chloride phthalocyanines (AlClPc) as the photosensitizing agent. Normal human fibroblast-containing collagen biomatrix was prepared and treated with an oil-in-water (o/a) AlClPc-loaded nanoemulsion (from 0.5 to 3.0 μM) and irradiated at a range of fluences (from 0.1 to 3.0 J/cm²) using a continuous-wave light-emitting diode (LED) irradiation system (660 nm). PBM at 1.2 J/cm² and AlClPc/NE at 0.5 μM modified the fibroblast signaling response under 3D conditions, promoting collagen synthesis, ROS production, MMP-9 secretion, proliferation of the actin network, and facile myofibroblastic differentiation. PBM alone (at 1.2 J/cm² and 0.3 J/cm²) had no significant effect on any of these parameters. The combined therapy affected myofibroblastic differentiation, inflammatory response, and extracellular matrix pliability, and should thus be examined further in subsequent studies considering that no side effects of PBM have been reported. Even though significant progress has been made in the field of phototherapy in recent years, it is necessary to further elucidate the detailed mechanisms underlying its effects already shown in 2D conditions to increase the acceptance of this beneficial and non-invasive therapeutic approach.

Photobiomodulation has rejuvenating effects on aged bone marrow mesenchymal stem cells

The plasticity and proliferative capacity of stem cells decrease with aging, compromising their tissue regenerative potential and therapeutic applications. This decline is directly linked to mitochondrial dysfunction. Here, we present an effective strategy to reverse aging of mouse bone marrow mesenchymal stem cells (BM-MSCs) by restoring their mitochondrial functionality using photobiomodulation (PBM) therapy. Following the characterization of young and aged MSCs, our results show that a near-infrared PBM treatment delivering 3 J/cm2 is the most effective modality for improving mitochondrial functionality and aging markers. Furthermore, our results unveil that young and aged MSCs respond differently to the same modality of PBM: whereas the beneficial effect of a single PBM treatment dissipates within 7 h in aged stem cells, it is lasting in young ones. Nevertheless, by applying three consecutive treatments at 24-h intervals, we were able to obtain a lasting rejuvenating effect on aged MSCs. Our findings are of particular significance for improving autologous stem cell transplantation in older individuals who need such therapies most.

Photobiomodulation: The Clinical Applications of Low-Level Light Therapy

BACKGROUND

Low-level light therapy (LLLT) is a recent addition to the pantheon of light-based therapeutic interventions. The absorption of red/near-infrared light energy, a process termed "photobiomodulation," enhances mitochondrial ATP production, cell signaling, and growth factor synthesis, and attenuates oxidative stress. Photobiomodulation is now highly commercialized with devices marketed directly to the consumer. In the gray area between the commercial and therapeutic sectors, harnessing the clinical potential in reproducible and scientifically measurable ways remains challenging.

OBJECTIVES

The aim of this article was to summarize the clinical evidence for photobiomodulation and discuss the regulatory framework for this therapy.

METHODS

A review of the clinical literature pertaining to the use of LLLT for skin rejuvenation (facial rhytids and dyschromias), acne vulgaris, wound healing, body contouring, and androgenic alopecia was performed.

RESULTS

A reasonable body of clinical trial evidence exists to support the role of low-energy red/near-infrared light as a safe and effective method of skin rejuvenation, treatment of acne vulgaris and alopecia, and, especially, body contouring. Methodologic flaws, small patient cohorts, and industry funding mean there is ample scope to improve the quality of evidence. It remains unclear if light-emitting diode sources induce physiologic effects of compararable nature and magnitude to those of the laser-based systems used in most of the higher-quality studies.

CONCLUSIONS

LLLT is here to stay. However, its ubiquity and commercial success have outpaced empirical approaches on which solid clinical evidence is established. Thus, the challenge is to prove its therapeutic utility in retrospect. Well-designed, adequately powered, independent clinical trials will help us answer some of the unresolved questions and enable the potential of this therapy to be realized.

Role of Visible Light on Skin Melanocytes: A Systematic Review

In the last few years, the focus of phototherapy has shifted toward the visible (400-700 nm) part of the electromagnetic spectrum of light. Lately, it has been demonstrated that visible light (VL) can have both beneficial and detrimental effects, especially on the skin. Previously and until now, the most harmful effects on the skin are associated with ultraviolet radiation (UVR). After exposure to natural light, the most evident and immediate change is observed on skin pigmentation. Various wavelengths within the visible spectrum have been reported to alter skin pigmentation. However, the underlying mechanisms are incompletely understood so far. The article aims to shed light on the progress made in the photobiology field (photobiomodulation, PBM) to study the role of visible light on skin melanocytes.

Role of Photo-Biomodulation Therapy in Facial Rejuvenation and Facial Plastic Surgery

Photo-biomodulation (PBM) also known as low-level laser therapy is a rising technology with multiple potential uses in medicine and recently in the cosmetic field for the treatment of skin conditions and skin rejuvenation. Due to its wound healing and anti-inflammatory properties, there is an increase in popularity in its use as adjunctive treatment before and after surgical procedures in the face and neck.

Photobiomodulation: A review of the molecular evidence for low level light therapy

Light energy is harnessed for therapeutic use in a number of ways, most recently by way of photobiomodulation (PBM). This phenomenon is a cascade of physiological events induced by the nonthermal exposure of tissue to light at the near infrared end of the visible spectrum. Therapeutic PBM has become a highly commercialized interest, marketed for everything from facial rejuvenation to fat loss, and diode-based devices are popular in both the clinic setting and for use at home. The lack of regulatory standards makes it difficult to draw clear conclusions about efficacy and safety but it is crucial that we understand the theoretical basis for PBM, so that we can engage in an honest dialogue with our patients and design better clinical studies to put claims of efficacy to the test. This article presents a summary of the science of PBM and examines the differences between laser light, on which much of the preclinical evidence is based and light from diodes, which are typically used in a clinical setting.

Mechanisms of repigmentation induced by photobiomodulation therapy in vitiligo

Photobiomodulation (PBM) therapy is based on the exposure of biological tissues to low-level laser light (coherent light) or light-emitting diodes (LEDs; noncoherent light), leading to the modulation of cellular functions, such as proliferation and migration, which result in tissue regeneration. PBM therapy has important clinical applications in regenerative medicine. Vitiligo is an acquired depigmentary disorder resulting from disappearance of functional melanocytes in the involved skin. Vitiligo repigmentation depends on available melanocytes derived from (a) melanocyte stem cells located in the bulge area of hair follicles and (b) the epidermis at the lesional borders, which contains a pool of functional melanocytes. Since follicular melanoblasts (MBs) are derived from the melanocyte stem cells residing at the bulge area of hair follicle, the process of vitiligo repigmentation presents a research model for studying the regenerative effect of PBM therapy. Previous reports have shown favourable response for treatment of vitiligo with a low-energy helium-neon (He-Ne) laser. This review focuses on the molecular events that took place during the repigmentation process of vitiligo triggered by He-Ne laser (632.8 nm, red light). Monochromatic radiation in the visible and infrared A (IRA) range sustains matrix metalloproteinase (MMP), improves mitochondrial function, and increases adenosine triphosphate (ATP) synthesis and O₂ consumption, which lead to cellular regenerative pathways. Cytochrome c oxidase in the mitochondria was reported to be the photoacceptor upon which He-Ne laser exerts its effects. Mitochondrial retrograde signalling is responsible for the cellular events by red light. This review shows that He-Ne laser initiated mitochondrial retrograde signalling via a Ca²⁺ -dependent cascade. The impact on cytochrome c oxidase within the mitochondria, an event that results in activation of CREB (cyclic-AMP response element binding protein)-related cascade, is responsible for the He-Ne laser promoting functional development at different stages of MBs and boosting functional melanocytes. He-Ne laser irradiation induced (a) melanocyte stem cell differentiation; (b) immature outer root sheath MB migration; (c) differentiated outer root sheath MB melanogenesis and migration; and (d) perilesional melanocyte migration and proliferation. These photobiomodulation effects result in perifollocular and marginal repigmentation in vitiligo.

Laser irradiation pretreatment improves endometrial preparation of frozen-thawed embryo transfer in recurrent implantation failure patients

Recurrent implantation failure (RIF) remains a clinical dilemma. Helium-Neon (He-Ne) laser irradiation has recently become more popular under certain clinical conditions. Given the unique therapeutic effects, we were interested in determining whether pretreatment with He-Ne laser irradiation prior to frozen-thawed embryo transfer (FET) would improve the microcirculation and cause the release of growth factors and cytokines, thus improving endometrial receptivity and the clinical pregnancy rates. Patients chose for themselves whether to proceed with (n = 29) or without (n = 31) pretreatment with He-Ne laser irradiation prior to FET. The clinical pregnancy rate (37.9%) and implantation rate (20.3%) were higher in the laser-treatment group than in the control group (35.5% and 15.9%, respectively, p = .844 and .518, respectively). The live birth rate was higher in the laser-treatment group (27.6% vs. 25.8%, respectively, p = .876) and the miscarriage rate was lower in the laser-treatment group (18.2% and 27.3%, respectively, p = .611). No side effects or complications from laser irradiation were encountered in patients who received the laser treatment. We concluded that pretreatment with He-Ne laser prior to FET may be an alternative choice for RIF-affected women; however, additional well-designed prospective studies are necessary to determine the precise clinical value of this treatment.

miRNA-183∼96∼182 regulates melanogenesis, cell proliferation and migration in B16 cells

Melanoma is a highly invasive malignant skin tumor having high metastatic rate and poor prognosis. The biology of melanoma is controled by miRNAs. The miRNA-183 cluster, which is composed of miRNA-183∼96∼182 genes, plays an important roles in tumor development. In order to investigate the role and action of miRNA-183 cluster in B16 cells, we overexpressed and knocked down miRNA-183 cluster in B16 cells. Using bioinformatics analysis, we predicted that the key framscript factor of melangenic genes. Microphthalmia-associated transcription factor (MITF) is one of the targets of miRNA-183 cluster. The results of Luciferase activity assays confirmed that MITF was targeted by miRNA-183 cluster. Overexpression and knockdown of miRNA-183 cluster in B16 cells resulted in down and up regulation of MITF expression, respectively at both mRNA and protein levels. Furthmore, overexpression and knockdown of the miRNA-183 cluster in B16 cells decreased and increased the expression of mRNA and protein of melangenic genes tyrosinase (TYR), and tyrosinase-related protein 1 (TYRP1), dopachrome-tautomerase (DCT), as well as the production of melanins and eumelanin production, respectively. On the proliferation and migration pathway, overexpression and knockdown of miRNA-183 cluster increased and decreased, respectively the expression of mRNA and protein of mitogen-activated protein kinase 1 (MEK1), extracellular regulated protein kinases1/2 (ERK1/2) and cAMP-responsive-element binding protein (CREB). These results indicated that miRNA-183 cluster regulated melanogenesis in B16 cells as well as cell proliferation and migration by directly targeting MITF through migration pathway.

A brief literature review and own clinical experience in prophylaxis of oral mucositis in children using low level laser therapy

OBJECTIVE

The article describes the experience of clinical application of low level laser therapy in pediatric oncology for the prevention and treatment of chemotherapy complications such as oral mucositis.

BACKGROUND

For this purpose, for the first time in the world non-invasive laser blood illumination is used on the sinocarotid zone (on the projection of the common carotid artery symmetrically) and popliteal fossa in order to stimulate the phagocytic activity of leukocytes.

METHODS

25 children with different oncological diseases were given non-invasive laser blood illumination treatment (904 nm, pulse mode, 100 ns, 50-150 Hz, 5-7 W, 4 cm², 1-2 minutes daily per each procedure) 1-3 days before the beginning of chemotherapy. For the objectification of the results of treatment, the phagocytic activity of leukocytes was evaluated.

RESULTS

None of the children who underwent low level laser therapy course had any complications and no cases of oral mucositis developed.

CONCLUSIONS

Clinical experience has shown high efficacy and safety of low level laser therapy aimed at preventing the development of complications of chemotherapy, primarily oral mucositis, and stimulating the phagocytic activity of leukocytes.

Efficacy of low-level light therapy for treatment of diabetic foot ulcer: A systematic review and meta-analysis of randomized controlled trials

AIMS

The goal of this systematic review and meta-analysis based on seven Randomized control trials (RCTs) is to examine whether Low-level light therapy (LLLT) is effective at healing diabetic foot ulcer (DFU) and to provide evidence-based recommendations and clinical guidelines for the future clinical treatment of DFUs.

METHODS

Medline, Embase, Scopus, Cochrane Library, and Web of Science databases were searched for studies published up to June 30, 2017, without language or data restrictions. RCTs that investigated the use of LLLT for DFU treatment were included. Standard methods of meta-analysis were performed to evaluate outcomes of LLLT on the healing of DFU.

RESULTS

Seven RCTs involving 194 participants were eligible for this systematic review and meta-analysis. The results of meta-analysis showed that LLLT has emerged as a potential noninvasive treatment for DFUs, as LLLT was found to effectively reduce the ulcer area [weighted mean difference (WMD) 34.18, 95% confidence intervals (CI) 19.38-48.99, P < 0.00001], improve the complete healing rate [odds ratio (OR) 6.72, 95% CI 1.99-22.64, P = 0.002]. Qualitative analysis of the included RCTs found that LLLT also played a role in the treatment of DFUs through promoting rapid granulation formation and shortening ulcer closure time, as well as alleviating foot ulcer pain. None of the treatment-related adverse event was reported.

CONCLUSIONS

LLLT was recognized as a potential method in the comprehensive treatment of DFUs. Further well designed and high-quality studies are required to confirm the role of LLLT in the management of DFUs.

The convergence theory for vitiligo: A reappraisal

Vitiligo is characterized by progressive loss of skin pigmentation. The search for aetiologic factors has led to the biochemical, the neurologic and the autoimmune theory. The convergence theory was then proposed several years ago to incorporate existing theories of vitiligo development into a single overview of vitiligo aetiology. The viewpoint that vitiligo is not caused only by predisposing mutations, or only by melanocytes responding to chemical/radiation exposure, or only by hyperreactive T cells, but rather results from a combination of aetiologic factors that impact melanocyte viability, has certainly stood the test of time. New findings have since informed the description of progressive depigmentation. Understanding the relative importance of such aetiologic factors combined with a careful selection of the most targetable pathways will continue to drive the next phase in vitiligo research: the development of effective therapeutics. In that arena, it is likewise important to acknowledge that pathways affected in some patients may not be altered in others. Taken together, the convergence theory continues to provide a comprehensive viewpoint of vitiligo aetiology. The theory serves to intertwine aetiologic pathways and will help to define pathways amenable to disease intervention in individual patients.

Cyclin-dependent kinase 5 regulates MAPK/ERK signaling in the skin of mice

Cyclin-dependent kinase 5 (CDK5) is a proline-directed serine/threonine kinase that has been shown to play important roles in many tissues except the nervous system. We previously reported that CDK5 showed differential expression in the transcriptome profiles of the skin of alpacas with different hair colors. To understand the functional role of CDK5 in hair color determination, we constructed CDK5-knockdown mice and identified the effect on the mitogen-activated protein kinase (MAPK) pathway in the mouse skin. Quantitative real-time polymerase chain reaction, co-immunoprecipitation, and western blotting were performed to analyze the effects of CDK5-knockdown on the MAPK pathway in mice. The results showed that MAP3K6 was inhibited by phosphorylated CDK5 through its activator CDK7. The decrease in MAP3K6 levels caused down-regulation of MEK1 and ERK expression, leading to the up-regulation of miR-143-3p, which targets MAP3K6 via Dicer. Taken together, our findings indicate that CDK5 functions in regulating the MAPK pathway. Given that MAP3K6 was inhibited in two directions, this mechanism can provide insight into the contributions of the MAPK/ERK pathway to the inhibition of melanin production.

Sox10 regulates skin melanocyte proliferation by activating the DNA replication licensing factor MCM5

BACKGROUND

The control of cell proliferation is a fundamental aspect of tissue formation in development and regeneration. A cell type that illustrates this point particularly well is the neural crest-derived melanocyte, the pigment cell of vertebrates, as melanocytes can be followed easily during development and their pigment is directly visible in the integument of the adult. In mammals, melanocytes undergo physiological cycles of loss and proliferative regeneration during the hair cycle, and their proliferation is also critical during wound healing, repigmentation of depigmented lesions, and in melanoma formation and progression. Hence, a thorough analysis of the molecular parameters controlling melanocyte proliferation is crucial for our understanding of the physiology of this cell type both in health and disease.

OBJECTIVE

SOX10 is a critical regulator in melanocytes and melanoma cells, but its specific role in their proliferation is far from clear. In this study we analyze the role of SOX10 in regulating mammalian melanocyte proliferation in a mouse model.

METHODS

The role of SOX10 in melanoblast proliferation was analyzed in Sox10/+ mice by co-staining for melanocyte-specific markers and cell proliferation. In vitro, the role of SOX10 was studied by manipulating its levels using RNAi and analyzing the effects on DNA synthesis and cell growth and on gene expression at the RNA and protein levels.

RESULTS

Reduction of Sox10 gene dose led to a reduction in the number of melanoblasts. Knockdown of Sox10 in melanocytes led to inhibition of cell proliferation and a decrease in the expression of the minichromosome maintenance complex component 5 (MCM5). In fact, SOX10 directly activated MCM5 transcription by binding to conserved SOX10 consensus DNA sequences in the MCM5 promoter. Furthermore, the defect in cell proliferation could be rescued partially by overexpression of MCM5 in Sox10 knockdown melanocytes.

CONCLUSION

The results suggest that the SOX10-MCM5 axis plays an important role in controlling melanocyte proliferation. Our findings provide novel insights into the regulatory mechanisms of melanocyte proliferation and may have implications for our understanding of the roles of SOX10 and MCM5 in abnormal melanocyte proliferation disorders such as cutaneous melanoma.

[LED lights in dermatology]

The use in dermatology of light-emitting diodes (LEDs) continues to be surrounded by controversy. This is due mainly to poor knowledge of the physicochemical phases of a wide range of devices that are difficult to compare to one another, and also to divergences between irrefutable published evidence either at the level of in vitro studies or at the cellular level, and discordant clinical results in a variety of different indications: rejuvenation, acne, wound healing, leg ulcers, and cutaneous inflammatory or autoimmune processes. Therapeutic LEDs can emit wavelengths ranging from the ultraviolet, through visible light, to the near infrared (247-1300 nm), but only certain bands have so far demonstrated any real value. We feel certain that if this article remains factual, then readers will have a different, or at least more nuanced, opinion concerning the use of such LED devices in dermatology.

Abrupt skin lesion border cutoff measurement for malignancy detection in dermoscopy images

Background

Automated skin lesion border examination and analysis techniques have become an important field of research for distinguishing malignant pigmented lesions from benign lesions. An abrupt pigment pattern cutoff at the periphery of a skin lesion is one of the most important dermoscopic features for detection of neoplastic behavior. In current clinical setting, the lesion is divided into a virtual pie with eight sections. Each section is examined by a dermatologist for abrupt cutoff and scored accordingly, which can be tedious and subjective.

Methods

This study introduces a novel approach to objectively quantify abruptness of pigment patterns along the lesion periphery. In the proposed approach, first, the skin lesion border is detected by the density based lesion border detection method. Second, the detected border is gradually scaled through vector operations. Then, along gradually scaled borders, pigment pattern homogeneities are calculated at different scales. Through this process, statistical texture features are extracted. Moreover, different color spaces are examined for the efficacy of texture analysis.

Results

The proposed method has been tested and validated on 100 (31 melanoma, 69 benign) dermoscopy images. Analyzed results indicate that proposed method is efficient on malignancy detection. More specifically, we obtained specificity of 0.96 and sensitivity of 0.86 for malignancy detection in a certain color space. The F-measure, harmonic mean of recall and precision, of the framework is reported as 0.87.

Conclusions

The use of texture homogeneity along the periphery of the lesion border is an effective method to detect malignancy of the skin lesion in dermoscopy images. Among different color spaces tested, RGB color space’s blue color channel is the most informative color channel to detect malignancy for skin lesions. That is followed by YCbCr color spaces Cr channel, and Cr is closely followed by the green color channel of RGB color space.

Ultra-structural effects of different low-level lasers on normal cultured human melanocytes: an in vitro comparative study

The aim of this study was to investigate the effects of the different types of low-level laser therapy (LLLT) on the ultra-structure and number of melanosomes in normal cultured human melanocytes. Specific effects of various types of LLLT on the ultra-structure of melanosomes have not yet been reported. Melanocytes were exposed to LLLT at an energy level of 2.0 J/cm², using a blue (457 nm), red (635 nm), or ultraviolet (UV) (355 nm) laser. After 72 h of irradiation, the melanocytes were fixed in 2.5 % glutaraldehyde (pH 7.2) phosphate buffer for 8 h and analyzed by transmission electron microscopy. Four developmental stages (I to IV) of melanosomes were observed, and their numbers were counted manually. The percentage of stages I, II, III, and IV melanosomes was 12.8, 14.2, 22.6, and 50.3 %, respectively, in the control (sham light). However, the melanosome percentages were 41.2, 5.4, 8.2, and 24.2 % in stages I, II, III, and IV, respectively, in the blue laser-treated group; 58.4, 6.1, 9.3, and 26.2 % for stages I, II, III, and IV, respectively, in the red laser-treated group; and 31.3, 11.1, 16.5, and 41.1 % for stages I, II, III, and IV, respectively, in the UV laser-treated group. The present data show that the amount of stage I is significantly higher (P < 0.0001) in the LLLT-treated cells compared to the control, which indicates significant stimulation of melanogenesis. The red laser was more effective than the other lasers. Moreover, the effects of LLLT on the ultra-structure of melanosomes need to be studied in a larger number of subject groups.

The activation of melanogenesis by p-CREB and MITF signaling with extremely low-frequency electromagnetic fields on B16F10 melanoma

Melanin in the skin determines the skin color, and decreased melanin causes many hypopigmentation disorders and increased damage to skin by ultraviolet B (UVB) light irradiation. Here, we stimulate melanogenesis in B16F10 melanoma cells by using specific frequencies of ELF-EMFs. In this study, we focus on the melanogenesis of EMF-ELFs and find that 60-75Hz ELF-EMFs upregulate melanin synthesis by stimulated expression of tyrosinase and TRP-1 through inhibition of phosphorylation ERK, activation of CREB, and MITF up-regulation in B16F10 melanoma cells. The results show that 60-75Hz ELF-EMFs significantly increase secreted melanin, cellular melanin content, and tyrosinase activity, and the cell mitochondria activity, cell viability, and cell membrane condition are unchanged. Furthermore, the protein expression level of MITF and p-CREB signaling pathway are significantly increased. Moreover, 60Hz ELF-EMFs reduce the phosphorylate of ERK in B16F10 melanoma cells. These findings indicate that stimulation of melanogenesis by using ELF-EMFs has therapeutic potential for treating hypopigmentation disorders such as vitiligo.

Mesenchymal Stem Cells Synergize with 635, 532, and 405 nm Laser Wavelengths in Renal Fibrosis: A Pilot Study

OBJECTIVE

To address whether a single treatment of one of three visible light wavelengths, 635, 532, and 405 nm (constant wave, energy density 2.9 J/m²), could affect the hallmarks of established renal fibrosis and whether these wavelengths could facilitate mesenchymal stem cell (MSC) beneficence.

BACKGROUND DATA

Chronic kidney disease is a global health problem with only 20% receiving care worldwide. Kidneys with compromised function have ongoing inflammation, including increased oxidative stress and apoptosis, peritubular capillary loss, tubular atrophy, and tubulointerstitial fibrosis. Promising studies have highlighted the significant potential of MSC-based strategies to mitigate fibrosis; however, reversal of established fibrosis has been problematic, suggesting that methods to potentiate MSC effects require further development. Laser treatments at visible wavelengths have been reported to enhance mitochondrial potential and available cellular ATP, facilitate proliferation, and inhibit apoptosis. We hypothesized that laser-delivered energy might provide wavelength-specific effects in the fibrotic kidney and enhance MSC responses.

MATERIALS AND METHODS

Renal fibrosis, established in C57BL6 mice following 21 days of unilateral ureter obstruction (UUO), was treated with one of three wavelengths alone or with autologous MSC. Mitochondrial activity, cell proliferation, apoptosis, and cytokines were measured 24 h later.

RESULTS

Wavelengths 405, 532, and 635 nm all significantly synergized with MSC to enhance mitochondrial activity and reduce apoptosis. Proliferative activity was observed in the renal cortices following combined treatment with the 532 nm laser and MSC; endothelial proliferation increased in response to the 635 nm laser alone and to the combined effects of MSC and the 405 nm wavelength. Reductions of transforming growth factor-β were observed with 532 nm alone and when combined with MSC.

CONCLUSIONS

Specific wavelengths of laser energy appear to induce different responses in renal fibrotic tissue. These findings support further study in the development of a customized laser therapy program of combined wavelengths to optimize MSC effects in the treatment of renal fibrosis.

Review of narrowband ultraviolet B radiation in vitiligo

Vitiligo is a common, acquired pigmentary disorder of unknown etiology with great impact on patient’s appearance and quality of life. It presents a therapeutic challenge to many dermatologists. Photochemotherapy using psoralen and ultraviolet A (UVA) therapy, topical and oral immunosuppresants, as well as cosmetic camouflage are also commonly employed with varying clinical efficacy. Phototherapy is a popular treatment option, which includes both of the generalized ultraviolet B (UVB) therapies, broadband UVB and narrowband UVB (NB-UVB). It has been used favorably, both alone as well as in combination with other agents like topical calcineurin inhibitors, vitamin-D analogs. Combination therapies are useful and may provide quicker regimentation and treat vitiligo with an additive mechanism of action than UVB phototherapy. Advances in technology may lead to the continuing use of UVB phototherapy as a treatment for vitiligo through the development of sophisticated devices and delivery systems as well as innovative application methods. These will provide increased therapeutic options for all vitiligo patients, particularly those with refractory disease. In this article, I have reviewed the available data pertaining to efficacy and safety issues for NB-UVB as monotherapy, its comparison with psoralen plus UVA and other modes of phototherapy, combination regimens that have been tried and future prospects of NB-UVB in vitiligo.

Low level laser therapy and hair regrowth: an evidence-based review

Despite the current treatment options for different types of alopecia, there is a need for more effective management options. Recently, low-level laser therapy (LLLT) was evaluated for stimulating hair growth. Here, we reviewed the current evidence on the LLLT effects with an evidence-based approach, focusing more on randomized controlled studies by critically evaluating them. In order to investigate whether in individuals presenting with hair loss (male pattern hair loss (MPHL), female pattern hair loss (FPHL), alopecia areata (AA), and chemotherapy-induced alopecia (CIA)) LLLT is effective for hair regrowth, several databases including PubMed, Google Scholar, Medline, Embase, and Cochrane Database were searched using the following keywords: Alopecia, Hair loss, Hair growth, Low level laser therapy, Low level light therapy, Low energy laser irradiation, and Photobiomodulation. From the searches, 21 relevant studies were summarized in this review including 2 in vitro, 7 animal, and 12 clinical studies. Among clinical studies, only five were randomized controlled trials (RCTs), which evaluated LLLT effect on male and female pattern hair loss. The RCTs were critically appraised using the created checklist according to the Critical Appraisal for Therapy Articles Worksheet created by the Center of Evidence-Based Medicine, Oxford. The results demonstrated that all the performed RCTs have moderate to high quality of evidence. However, only one out of five studies performed intention-to-treat analysis, and only another study reported the method of randomization and subsequent concealment of allocation clearly; all other studies did not include this very important information in their reports. None of these studies reported the treatment effect of factors such as number needed to treat. Based on this review on all the available evidence about effect of LLLT in alopecia, we found that the FDA-cleared LLLT devices are both safe and effective in patients with MPHL and FPHL who did not respond or were not tolerant to standard treatments. Future randomized controlled trials of LLLT are strongly encouraged to be conducted and reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement to facilitate analysis and comparison.

Microphthalmia-associated transcription factor/T-box factor-2 axis acts through Cyclin D1 to regulate melanocyte proliferation

OBJECTIVES

Control of cell proliferation is critical for accurate cell differentiation and tissue formation, during development and regeneration. Here, we have analysed the role of microphthalmia-associated transcription factor MITF and its direct target, T-box factor TBX2, in regulating proliferation of mammalian neural crest-derived melanocytes.

MATERIALS AND METHODS

Immunohistochemistry was used to examine spatial and temporal expression of TBX2 in melanocytes in vivo. RNAi and cell proliferation analysis were used to investigate functional roles of TBX2. Furthermore, quantitative RT-PCR, western blot analysis and flow cytometry were used to further scrutinize molecular mechanisms underlying TBX2-dependent cell proliferation.

RESULTS

TBX2 was found to be co-expressed with MITF in melanocytes of mouse hair follicles. Specific Tbx2 knockdown in primary neural crest cells led to inhibition MITF-positive melanoblast proliferation. Tbx2 knockdown in melan-a cells led to reduction in Cyclin D1 expression and G1-phase cell cycle arrest. TBX2 directly activated Ccnd1 transcription by binding to a specific sequence in the Ccnd1 promoter, and the defect in cell proliferation could be rescued partially by overexpression of Cyclin D1 in Tbx2 knockdown melanocytes.

CONCLUSIONS

Results suggest that the Mitf-Tbx2-Cyclin D1 pathway played an important role in regulation of melanocyte proliferation, and provided novel insights into the complex physiology of melanocytes.

A comparative study of the effects of different low-level lasers on the proliferation, viability, and migration of human melanocytes in vitro

The aim of this study was to investigate the effects of different low-level laser therapies (LLLTs) of various wavelengths and energies on normal cultured human melanocytes. Various studies have shown the effects of LLLs on various types of cultured cells. Presently, little is known about the biological effects of LLLTs on melanocytes. Melanocytes were exposed to LLLT at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 J/cm(2) using a blue (457 nm), red (635 nm), or ultraviolet (UV) (355 nm) laser. Melanocyte viability, proliferation, and migration were monitored at 72 h after irradiation. The blue (P < 0.001) and red (P < 0.001 and P < 0.01) lasers significantly enhanced viability at 0.5 to 2.0 J/cm(2), whereas the UV laser (P < 0.001) could significantly enhance viability only at 0.5 and 1.0 J/cm(2) compared with controls. The blue and red lasers also significantly enhanced the proliferation of the melanocytes at 0.5 to 2.0 J/cm(2) (P < 0.001), and the UV laser significantly enhanced proliferation at 0.5 to 1.5 J/cm(2) (P < 0.001 and P < 0.01) compared with controls. The blue laser significantly enhanced melanocyte migration at 0.5 to 4.0 J/cm(2) (P < 0.001 to P < 0.05), but the red (P < 0.001 and P < 0.01) and UV (P < 0.001 to P < 0.05) lasers could significantly enhance such migration at 0.5 to 1.0 J/cm(2) and 0.5 to 2.0 J/cm(2), respectively, compared with controls. LLLT at low energy densities is able to significantly increase melanocyte viability, proliferation, and migration in vitro, and at higher energy densities, it gives non-stimulatory results. Additionally, the blue laser was the best among the three lasers. These findings might have potential application in vitiligo treatment in future.

Concise review of recent studies in vitiligo

Vitiligo is an acquired pigmentry disorder of the skin and mucous membranes which manifests as white macules and patches due to selective loss of melanocytes. Etiological hypotheses of vitiligo include genetic, immunological, neurohormonal, cytotoxic, biochemical, oxidative stress and newer theories of melanocytorrhagy and decreased melanocytes survival. There are several types of vitiligo which are usually diagnosed clinically and by using a Wood's lamp; also vitiligo may be associated with autoimmune diseases, audiological and ophthalmological findings or it can be a part of polyendocrinopathy syndromes. Several interventions are available for the treatment for vitiligo to stop disease progression and/or to attain repigmentation or even depigmentation. In this article, we will present an overall view of current standing of vitiligo research work especially in the etiological factors most notably the genetic components, also, types and associations and various and newer treatment modalities.

Low-level laser therapy for fat layer reduction: a comprehensive review

BACKGROUND AND OBJECTIVE

Low-level laser (light) therapy (LLLT) is a noninvasive, nonthermal approach to disorders requiring reduction of pain and inflammation and stimulation of healing and tissue regeneration. Within the last decade, LLLT started being investigated as an adjuvant to liposuction, for noninvasive body contouring, reduction of cellulite, and improvement of blood lipid profile. LLLT may also aid autologous fat transfer procedures by enhancing the viability of adipocytes. However the underlying mechanism of actions for such effects still seems to be unclear. It is important, therefore, to understand the potential efficacy and proposed mechanism of actions of this new procedure for fat reduction.

MATERIALS AND METHODS

A review of the literature associated with applications of LLLT related to fat layer reduction was performed to evaluate the findings from pre-clinical and clinical studies with respect to the mechanism of action, efficacy, and safety.

RESULTS

The studies as of today suggest that LLLT has a potential to be used in fat and cellulite reduction as well as in improvement of blood lipid profile without any significant side effects. One of the main proposed mechanism of actions is based upon production of transient pores in adipocytes, allowing lipids to leak out. Another is through activation of the complement cascade which could cause induction of adipocyte apoptosis and subsequent release of lipids.

CONCLUSION

Although the present studies have demonstrated safety and efficacy of LLLT in fat layer reduction, studies demonstrating the efficacy of LLLT as a stand-alone procedure are still inadequate. Moreover, further studies are necessary to identify the mechanism of action.