Red light interferes in UVA-induced photoaging of human skin fibroblast cells

Assembling AgAuSe Quantum Dots with Peptidoglycan and Neutrophils to Realize Enhanced Tumor Targeting, NIR (II) Imaging, and Sonodynamic Therapy

Significant progress is made in drug delivery systems, but they still face problems such as poor stability in vivo, off-target drugs, and difficulty in crossing biological barriers. It is urgent to realize efficient targeted delivery and precisely controlled sustained release of drugs by using the integrated nanoplatform. Theranostic nanoplatform is a new biomedical technology that combines diagnosis or monitoring of diseases with treatment. Here, an integrated strategy of diagnosis and treatment is reported for delivering NIR-II imaged and therapeutic AgAuSe quantum dots (QDs) carried by peptidoglycan multilayer networks of bacteria to hitchhike circulating neutrophils for targeting the tumor. The assembled nanomaterials have good stability, which can not only initiate endogenous cells for drug delivery and achieve efficient targeting, but also guide drug imaging with excellent fluorescence property. Meanwhile, the elimination of established solid tumor is achieved with the administration of sonodynamic therapy without recurrence. This drug system expands the application of endogenous cell to participate in drug delivery system. Thus, the assembly strategy demonstrates the potential of endogenous neutrophils in functioning as natural drug vehicles and the application of NIR-II fluorescent QDs in biomedical engineering.

The role of sirtuins in dermal fibroblast function

The sirtuins are a family of seven proteins that perform a variety of dermatological functions and help maintain both the structure and function of the skin. More specifically, the sirtuins have been shown to be altered in multiple dermal cell types including dermal fibroblasts. The functions of dermal fibroblasts are extensive, and include playing a significant role in wound healing as well as helping to maintain the integrity of the skin. As dermal fibroblasts age, they can undergo a state of permanent cell cycle arrest, known as cellular senescence. This senescent process can occur as a result of various stressors, including oxidative stress, ultraviolet radiation -induced stress, and replicative stress. In recent years, there has been a growing interest in both enhancing the cutaneous fibroblast’s ability to facilitate wound healing and altering fibroblast cellular senescence. Thus, in this review, we examine the relationship between sirtuin signaling and dermal fibroblasts to understand how this family of proteins may modulate skin conditions ranging from the wound healing process to photocarcinogenesis associated with fibroblast senescence. Additionally, we offer supporting data from experiments examining the relationship between fibroblast senescence and sirtuin levels in an oxidative stress model indicating that senescent dermal fibroblasts exhibit diminished sirtuin levels. Furthermore, we survey the research on the role of sirtuins in specific dermatological disease states that where dermal fibroblast function has been implicated. Finally, we conclude with outlining potential clinical applications of sirtuins in dermatology. In sum, we find that the literature on the involvement of sirtuins in dermal fibroblasts is limited, with research still in its early stages. Nevertheless, intriguing preliminary findings merit additional investigation into the clinical implications of sirtuins in dermatology.

Treatment with LEDs at a wavelength of 642 nm enhances skin tumor proliferation in a mouse model

Photobiomodulation (PBM) is attracting increased attention in the fields of dermatology and cosmetics. PBM with a variety of light parameters has been used widely in skin care, but can cause certain types of unwanted cells to proliferate in the skin; this can lead to skin tumors, such as papillomas and cancers. We constructed a mouse model of human skin tumors using DMBA as an initiator and TPA as a promoter, and confirmed that LEDs with a wavelength of 642 nm (red light) increased tumor size, epidermal thickness, and systemic proinflammatory cytokine levels. These results indicated that skin tumor cell proliferation may result from the use of 642 nm LEDs, suggesting the need for regulation of skin care based on LED light therapy.

In Vitro Effect of Photodynamic Therapy with Different Lights and Combined or Uncombined with Chlorhexidine on Candida spp

Candidiasis is very common and complicated to treat in some cases due to increased resistance to antifungals. Antimicrobial photodynamic therapy (aPDT) is a promising alternative treatment. It is based on the principle that light of a specific wavelength activates a photosensitizer molecule resulting in the generation of reactive oxygen species that are able to kill pathogens. The aim here is the in vitro photoinactivation of three strains of Candida spp., Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258, using aPDT with different sources of irradiation and the photosensitizer methylene blue (MB), alone or in combination with chlorhexidine (CHX). Irradiation was carried out at a fluence of 18 J/cm² with a light-emitting diode (LED) lamp emitting in red (625 nm) or a white metal halide lamp (WMH) that emits at broad-spectrum white light (420–700 nm). After the photodynamic treatment, the antimicrobial effect is evaluated by counting colony forming units (CFU). MB-aPDT produces a 6 log₁₀ reduction in the number of CFU/100 μL of Candida spp., and the combination with CHX enhances the effect of photoinactivation (effect achieved with lower concentration of MB). Both lamps have similar efficiencies, but the WMH lamp is slightly more efficient. This work opens the doors to a possible clinical application of the combination for resistant or persistent forms of Candida infections.

Natural Compounds and PCL Nanofibers: A Novel Tool to Counteract Stem Cell Senescence

Tissue homeostasis mainly depends on the activity of stem cells to replace damaged elements and restore tissue functions. Within this context, mesenchymal stem cells and fibroblasts are essential for maintaining tissue homeostasis in skin, in particular in the dermis. Modifications in collagen fibers are able to affect stem cell features. Skin properties can be significantly reduced after injuries or with aging, and stem cell niches, mainly comprising extracellular matrix (ECM), may be compromised. To this end, specific molecules can be administrated to prevent the aging process induced by UV exposure in the attempt to maintain a youngness phenotype. NanoPCL-M is a novel nanodevice able to control delivery of Mediterranean plant myrtle (Myrtus communis L.) extracts. In particular, we previously described that myrtle extracts, rich in bioactive molecules and nutraceuticals, were able to counteract senescence in adipose derived stem cells. In this study, we analyzed the effect of NanoPCL-M on skin stem cells (SSCs) and dermal fibroblasts in a dynamic cell culture model in order to prevent the effects of UV-induced senescence on proliferation and collagen depot. The BrdU assay results highlight the significantly positive effect of NanoPCL-M on the proliferation of both fibroblasts and SSCs. Our results demonstrate that-M is able to preserve SSCs features and collagen depot after UV-induced senescence, suggesting their capability to retain a young phenotype.

The inflammation and reactive oxygen species regulated by Nrf2 and NF-κB signaling pathways in 630-nm light-emitting diode irradiation treated THP-1 monocytes/macrophages

Because of a large number of macrophages and its secreted pro-inflammatory factors in the synovial fluid of patients with rheumatoid arthritis, the present study aimed to investigate the effect and mechanism of 630-nm LED exposure on monocytes/macrophages and its anti-inflammatory effect. The THP-1 monocytes and PMA-induced THP-1 macrophages (THP-1 macrophages) were employed and irradiated by 630-nm LED for different time and times, and then measure the pro-inflammatory cytokines production by RT-qPCR and Milliplex MAP Multiplex assay, the proteins involved in inflammation pathway and reactive oxygen species (ROS) levels in the cells were detected by Western blot and DCFH-DA method. The exposure dose of red LED (15.3 J/cm², 30.6 J/cm²) were determined as no-influence on the cell proliferation, the pro-inflammatory factors TNF-α and IL-1β mRNAs, and secretions in supernatant of THP-1 macrophages were significantly decreased after LED exposure. The ROS production was blocked in THP-1 monocytes and THP-1 macrophages after treatment of LED. Finally, the phosphorylated NF-κB proteins which involved in inflammation pathway significantly decreased, and its inhibitors Nrf2 were slightly upregulated. The effects of LED anti-inflammation response are dependent on the mechanism of inhibiting ROS level and regulating NF-κB signaling pathways by increasing Nrf2 expression in the cells. It is suggested that 630-nm LED could decrease pro-inflammation in immune cells, and it may be a beneficial adjunct therapy in relieving inflammation of patients with rheumatoid arthritis.

Bioengineered Skin Intended as In Vitro Model for Pharmacosmetics, Skin Disease Study and Environmental Skin Impact Analysis

This review aims to be an update of Bioengineered Artificial Skin Substitutes (BASS) applications. At the first moment, they were created as an attempt to replace native skin grafts transplantation. Nowadays, these in vitro models have been increasing and widening their application areas, becoming important tools for research. This study is focus on the ability to design in vitro BASS which have been demonstrated to be appropriate to develop new products in the cosmetic and pharmacology industry. Allowing to go deeper into the skin disease research, and to analyze the effects provoked by environmental stressful agents. The importance of BASS to replace animal experimentation is also highlighted. Furthermore, the BASS validation parameters approved by the OECD (Organisation for Economic Co-operation and Development) are also analyzed. This report presents an overview of the skin models applicable to skin research along with their design methods. Finally, the potential and limitations of the currently available BASS to supply the demands for disease modeling and pharmaceutical screening are discussed.

Attenuation of UVB-Induced Photo-Aging by Polyphenolic-Rich Spatholobus Suberectus Stem Extract Via Modulation of MAPK/AP-1/MMPs Signaling in Human Keratinocytes

It is well known that ultraviolet light activates mitogen-activated protein (MAP) kinase by increasing the reactive oxygen species (ROS) in the body, enhancing activating protein 1(AP-1) complexes (c-Jun and c-Fos), increasing matrix metalloproteinases (MMPs) and degrading collagen and elastin. In this study, we confirmed that polyphenolic rich Spatholobus suberectus (SS) stem extracts suppressed ultraviolet (UV)-induced photo-aging. The major active components of SS stem extracts were identified as gallic acid, catechin, vanillic acid, syringic acid and epicatechin. The aqueous and ethanolic extracts of the stem of SS (SSW and SSE, respectively) significantly reduced the elastase enzyme activity. Moreover, both extracts were suppressed the ROS generation and cellular damage induced by UVB in HaCaT cells. Our results also revealed that SSE could regulate the expression of MMPs, tissue inhibitor of matrix metalloproteinase (TIMP)-1, collagen type I alpha 1 (COL1A1), elastin (ELN) and hyaluronan synthase 2 (HAS2) at their transcriptional and translational level. Furthermore, SSE was blocked the UVB-induced phosphorylation of mitogen-activated protein kinases (MAPKs), nuclear factor-kappa B (NF-κB) and c-Jun. Moreover, combination of syringic acid, epicatechin and vanillic acid showed strong synergistic effects on elastase inhibition activity, in which the combination index (CI) was 0.28. Overall, these results strongly suggest that the polyphenolics of SSE exert anti-ageing potential as a natural biomaterial to inhibit UVB-induced photo-aging.

Effects of irradiance on UVA-induced skin aging

BACKGROUND

Ultraviolet A (UVA) radiation is the most relevant component of solar radiation-induced skin aging. Sunscreens were used to minimize the harmful effects of UV radiation on our skin by reducing UV irradiance. We previously found that at equivalent fluence, UVB radiation at low irradiance (LI) has higher photocarcinogenic potential as compared to its high irradiance (HI) counterpart.

OBJECTIVES

To examine the effects of equivalent fluence of UVA radiation administered at different irradiance on photoaging.

METHODS

Both the hairless mice (SKH-1) and human dermal fibroblasts were irradiated with high irradiance UVA (HIUVA) or low irradiance UVA (LIUVA; 50% irradiance of HIUVA) at equivalent fluence. Parameters related to skin photoaging were evaluated.

RESULTS

For hairless mice receiving equivalent fluence of UVA radiation, LIUVA treated mice showed prominent skin aging as compared to its HIUVA treated counterpart. In addition, LIUVA radiation induced higher reactive oxygen species (ROS) production and c-Jun N-terminal kinases (JNK) phosphorylation as compared to their HIUVA treated counterparts. Pretreatment with N-acetylcysteine (NAC) abrogate the difference between HI and LIUVA radiation on fibroblasts in terms of intracellular ROS, JNK phosphorylation, MMP-1 expression and type I collagen expression.

CONCLUSION

UVA radiation administered at LI (a scenario similar to sunscreen use) led to more severe aging process as compared to its HI counterpart. Unexpected negative effect may be imposed on the skin if sunscreen use is accompanied by longer duration spent under the sun.

Transcriptomic analysis of human dermal fibroblast cells reveals potential mechanisms underlying the protective effects of visible red light against damage from ultraviolet B light

BACKGROUND

Ultraviolet B (UVB) radiation is a major cause of skin photodamage, including the damage associated with photodermatoses, aging, and cancer. Although many studies have shown that red light has photoprotective effects on skin, the mechanisms underlying these effects are still poorly understood.

OBJECTIVE

The aim of this study was to identify the photoprotective effects of visible red light against UVB-induced skin damage in normal human dermal fibroblast cells using a transcriptomic approach.

METHODS

Next-generation sequencing-based transcriptomic analyses were used to profile transcriptomic alterations and identify genes that are differentially expressed by visible red light and by UVB exposure. To understand the biological networks among identified genes, a literature-based biological pathway analysis was performed. Quantitative real-time polymerase chain reaction assays were used for mRNA-level validation of selected key genes.

RESULTS

We observed that visible red light contributes to skin cell protection against UVB by modulating gene expression that enhances the adaptive response to redox and inflammatory balancing and by upregulating genes involved in DNA excision repair processes. We also identified that several key genes in the red light-induced biological network were differentially regulated.

CONCLUSIONS

Visible red light enhanced the UVB-protective effects in normal human skin cells via the transcriptomic modulation of genes involved in cell-protective processes. Our findings from this next-generation sequencing analysis may lead to a better understanding of the cytoprotective effects of visible red light and provide direction for further molecular or mechanistic studies.

ATR-IR study of skin components: Lipids, proteins and water. Part II: Near infrared radiation effect

Near infrared (NIR) radiation has been widely used in medicine and biomedical engineering. In spite of numerous studies the molecular mechanism of NIR radiation on biological systems has not been established as yet. The objective of this work was examination of the effect of NIR irradiation on the skin components. Modifications of lipid organization after NIR exposure vs. temperature (from 20 to 90 °C) have been investigated using Attenuated Total Reflectance Infrared (ATR-IR) spectroscopy. This work is a continuation of our previous studies on the temperature effect on skin components [1]. After NIR exposure a temperature shift of the phase transition from the orthorhombic to hexagonal packing (≈40 °C) has been observed. In contrast, the second phase transition temperature (≈70 °C) is almost invariable. The phase transitions in lipids were correlated with modifications of the structure of water and proteins. To our knowledge, for the first time the temperatures of the phase transitions after NIR exposure were investigated.

Efficacy and safety of combined high-dose interferon and red light therapy for the treatment of human papillomavirus and associated vaginitis and cervicitis: A prospective and randomized clinical study

BACKGROUND

We evaluated the efficacy and safety of combined high-dose interferon (IFN) and red light therapy for the treatment of subclinical and latent human papillomavirus (HPV) infections.

METHODS

Ninety women diagnosed with subclinical or latent HPV infection were randomized to receive topical application of low-dose recombinant IFNα-2b (1 million IU), high-dose IFNα-2b (9 million IU), or a combination of high-dose IFNα-2b and red light therapy on the cervix and vagina. All patients received treatment once daily for 4 weeks. HPV titer was measured immediately and 4, 8, and 12 weeks after treatment to determine the rates of viral clearance and infection cure. Treatment of HPV-associated vaginitis and cervicitis was also evaluated.

RESULTS

Results showed that immediately and 4, 8, and 12 weeks after treatment, the HPV clearance rates and infection cure rates were higher in the high-dose IFN and combination groups compared to the low-dose IFN group. High-dose IFN and combination therapies were significantly effective against both low-risk and high-risk HPV infections. Although the cure rates for vaginitis and cervicitis were significantly higher in the high- compared to the low-dose IFN group, rates were even higher in the combination group compared to the high-dose IFN group. Mild adverse effects were reported by a very small subset of patients (3/30) in the combination group.

CONCLUSIONS

This study suggests that combination of high-dose IFN and red light therapy is safe and effective against subclinical and latent HPV infections.

A clinical review of phototherapy for psoriasis

Psoriasis is an autoimmune inflammatory skin disease. In the past several decades, phototherapy has been widely used to treat stable psoriatic lesions, including trunk, scalp, arms and legs, and partial nail psoriasis. A variety of light/lasers with different mechanisms of action have been developed for psoriasis including ultraviolet B (UVB), psoralen ultraviolet A (PUVA), pulsed dye laser (PDL), photodynamic therapy (PDT), intense pulsed light (IPL), light-emitting diodes (LED), and so on. Because light/laser each has specific therapeutic and adverse effects, it is important to adequately choose the sources and parameters in management of psoriasis with different pathogenic sites, severities, and duration of the disorder. This review aims at providing most updated clinic information to physicians about how to select light/laser sources and individual therapeutic regimens. To date, UV light is primarily for stable plaque psoriasis and PDL for topical psoriatic lesions with small area, both of which are safe and effective. On the other hand, PUVA has better curative effects than UVB for managing refractory psoriasis plaques, if its side effects can be better controlled. PDL provides optimal outcomes on nail psoriasis compared with other lasers. Although the trails of low-level light/laser therapy (LLLT) are still small, the near infrared (NIR) and visible red light with low energy show promise for treating psoriasis due to its strong penetration and encouraging photobiomodulation. IPL is rarely reported for psoriasis treatment, but PDT-IPL has been found to offer a moderate effect on nail psoriasis. In brief, various phototherapies have been used either in different combinations or as monotherapy. The modality has become a mainstay in the treatment of mild-to-moderate psoriasis without systemic adverse events in today's clinical practice.

Polycomb group proteins: Novel molecules associated with ultraviolet A-induced photoaging of human skin

Epigenetic repressor polycomb group (PcG) proteins are thought to serve a role in a number of cellular processes, including carcinogenesis, senescence, apoptosis and DNA repair. In the present study, long-wave ultraviolet A (UVA) was used to irradiate human skin fibroblasts (HSFs) and embryonic skin fibroblasts (ESFs) in order to simulate photoaging of the skin. The results of cell proliferation, apoptosis, hyaluronic acid (HA) content and reverse transcription-quantitative polymerase chain reaction assays revealed that the expression levels of genes encoding key PcG proteins (BMI-1 and EZH2) were altered. In addition, the expression levels of these genes were associated with the expression of enzymes that regulate HA synthesis. Furthermore, the expression levels of PcG proteins differed between HSFs and ESFs, suggesting that PcG proteins serve a role in altering HA synthesis during the UVA-induced fibroblast aging process. This signaling pathway may represent a novel molecular mechanism regulating the photoaging of the skin. The findings of the present study provide important insights into the underlying mechanisms of photoaging of the human skin. Further studies are required to clarify the molecular mechanisms underling skin aging and to identify targets for the clinical treatment of photoaging.

Sirtuins in Skin and Skin Cancers

The sirtuins are a family of proteins that comprise class III of the histone deacetylases. These NAD+-dependent proteins have been found to be intricately involved in a variety of important and skin-relevant cellular functions and processes, including aging, UV damage response, oxidative stress, and wound repair. In addition, recent research is unraveling the role of sirtuins in a variety of skin diseases, including melanoma and nonmelanoma skin cancers. In this review, we provide a discussion on the potential roles and implications of different sirtuins in skin-specific cellular processes, which may have relevance to skin health and skin diseases. Based on the available literature, the sirtuins appear to be important targets in the management of a variety of skin diseases from cosmetic (e.g., skin aging) to fatal conditions (e.g., melanoma).

Honokiol protects skin cells against inflammation, collagenolysis, apoptosis, and senescence caused by cigarette smoke damage

BACKGROUND

Pollution, especially cigarette smoke, is a major cause of skin damage.

OBJECTIVES

To assess the effects of the small molecule polyphenol, honokiol, on reversing cigarette smoke-induced damage in vitro to relevant skin cells.

METHODS

Keratinocytes (HaCat) cultures were exposed to cigarette smoke and, after 48 hours, IL-1α and IL-8 were measured in cell supernatants. Moreover, TIMP-2 production, apoptosis rate, and senescence β-galactosidase expression were evaluated in primary human foreskin fibroblasts (HFF-1) cultures.

RESULTS

Honokiol at 10 μm reduced IL-1α production by 3.4 folds (P < 0.05) and at 10 and 20 μm reduced IL-8 by 23.9% and 53.1% (P < 0.001), respectively, in HaCat keratinocytes. In HFF-1, honokiol restored TIMP-2 production by 96.9% and 91.9% (P < 0.001), respectively, at 10 and 20 μm, as well as reduced apoptosis by 47.1% (P < 0.001) and 41.3% (P < 0.01), respectively. Finally, honokiol reduced senescence-associated β-galactosidase expression in HFF-1.

CONCLUSION

Honokiol protects both HFF-1 and HaCat against cigarette smoke-induced inflammation, collagenolysis, apoptosis, and senescence.

A Protective Mechanism of Visible Red Light in Normal Human Dermal Fibroblasts: Enhancement of GADD45A-Mediated DNA Repair Activity

The phototherapeutic effects of visible red light on skin have been extensively investigated, but the underlying biological mechanisms remain poorly understood. We aimed to elucidate the protective mechanism of visible red light in terms of DNA repair of UV-induced oxidative damage in normal human dermal fibroblasts. The protective effect of visible red light on UV-induced DNA damage was identified by several assays in both two-dimensional and three-dimensional cell culture systems. With regard to the protective mechanism of visible red light, our data showed alterations in base excision repair mediated by growth arrest and DNA damage inducible, alpha (GADD45A). We also observed an enhancement of the physical activity of GADD45A and apurinic/apyrimidinic endonuclease 1 (APE1) by visible red light. Moreover, UV-induced DNA damages were diminished by visible red light in an APE1-dependent manner. On the basis of the decrease in GADD45A-APE1 interaction in the activating transcription factor-2 (ATF2)-knockdown system, we suggest a role for ATF2 modulation in GADD45A-mediated DNA repair upon visible red light exposure. Thus, the enhancement of GADD45A-mediated base excision repair modulated by ATF2 might be a potential protective mechanism of visible red light.

The skin aging exposome

The term "exposome" describes the totality of exposures to which an individual is subjected from conception to death. It includes both external and internal factors as well as the human body's response to these factors. Current exposome research aims to understand the effects all factors have on specific organs, yet today, the exposome of human skin has not received major attention and a corresponding definition is lacking. This review was compiled with the collaboration of European scientists, specialized in either environmental medicine or skin biology. A comprehensive review of the existing literature was performed using PubMed. The search was restricted to exposome factors and skin aging. Key review papers and all relevant, epidemiological, in vitro, ex vivo and clinical studies were analyzed to determine the key elements of the exposome influencing skin aging. Here we propose a definition of the skin aging exposome. It is based on a summary of the existing scientific evidence for the role of exposome factors in skin aging. We also identify future research needs which concern knowledge about the interaction of distinct exposomal factors with each other and the resulting net effects on skin aging and suggest some protective measures.

Red Light Combined with Blue Light Irradiation Regulates Proliferation and Apoptosis in Skin Keratinocytes in Combination with Low Concentrations of Curcumin

Curcumin is a widely known natural phytochemical from plant Curcuma longa. In recent years, curcumin has received increasing attention because of its capability to induce apoptosis and inhibit cell proliferation as well as its anti-inflammatory properties in different cancer cells. However, the therapeutic benefits of curcumin are severely hampered due to its particularly low absorption via trans-dermal or oral bioavailability. Phototherapy with visible light is gaining more and more support in dermatological therapy. Red light is part of the visible light spectrum, which is able to deeply penetrate the skin to about 6 mm, and directly affect the fibroblast of the skin dermis. Blue light is UV-free irradiation which is fit for treating chronic inflammation diseases. In this study, we show that curcumin at low concentrations (1.25–3.12 μM) has a strong anti-proliferative effect on TNF-α-induced psoriasis-like inflammation when applied in combination with light-emitting-diode devices. The treatment was especially effective when LED blue light at 405 nm was combined with red light at 630 or 660 nm, which markedly amplified the anti-proliferative and apoptosis-inducing effects of curcumin. The experimental results demonstrated that this treatment reduced the viability of human skin keratinocytes, decreased cell proliferation, induced apoptosis, inhibited NF-κB activity and activated caspase-8 and caspase-9 while preserving the cell membrane integrity. Moreover, the combined treatment also down-regulated the phosphorylation level of Akt and ERK. Taken together, our results indicated that the combination of curcumin with LED blue light united red light irradiation can attain a higher efficiency of regulating proliferation and apoptosis in skin keratinocytes.