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

Photobiomodulation with 630-nm LED Inhibits M1 Macrophage Polarization via STAT1 Pathway Against Sepsis-Induced Acute Lung Injury

Background: Sepsis-induced acute lung injury (ALI) is a clinical syndrome characterized by excessive uncontrolled inflammation. Photobiomodulation such as light-emitting diode (LED) irradiation has been used to attenuate inflammatory disease. Objective: The protective effect of 630 nm LED irradiation on sepsis-induced ALI remains unknown. The purpose of this study was to investigate the role of 630 nm LED irradiation in sepsis-induced ALI and its underlying mechanism. Methods and results: C57BL/6 mice were performed cecal ligation and puncture (CLP) for 12 h to generate experimental sepsis models. Histopathology analysis showed that alveolar injury, inflammatory cells infiltration, and hemorrhage were suppressed in CLP mice after 630 nm LED irradiation. The ratio of wet/dry weigh of lung tissue was significantly inhibited by irradiation. The number of leukocytes was reduced in bronchoalveolar lavage fluid. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) results and enzyme-linked immunosorbent assay showed that 630 nm LED irradiation significantly inhibited the mRNA and protein levels of M1 macrophage-related genes in the lung of CLP-induced septic mice. Meanwhile, LED irradiation significantly inhibited signal transducer and activator of transcription 1 (STAT1) phosphorylation in the lung of septic mice. In vitro experiments showed that 630 nm LED irradiation significantly inhibited M1 genes mRNA and protein expression in THP-1-derived M1 macrophages without affecting the cell viability. LED irradiation also significantly inhibited the level of STAT1 phosphorylation in THP-1-derived M1 macrophages. Conclusions: We concluded that 630 nm LED is promising as a treatment against ALI through inhibiting M1 macrophage polarization, which is associated with the downregulation of STAT1 phosphorylation.

Exploring the Safety and Efficacy of Organic Light-Emitting Diode in Skin Rejuvenation and Wound Healing

PURPOSE

Photobiomodulation (PBM), encompassing low-energy laser treatment and light-emitting diode (LED) phototherapy, has demonstrated positive impacts on skin rejuvenation and wound healing. Organic light-emitting diodes (OLEDs) present a promising advancement as wearable light sources for PBM. However, the biological and biochemical substantiation of their skin rejuvenation and wound healing effects remains limited. This study aimed to ascertain the safety and efficacy of OLEDs as a next-generation PBM modality through comprehensive in vitro and in vivo investigations.

MATERIALS AND METHODS

Cell viability assays and human ex vivo skin analyses were performed after exposure to OLED and LED irradiation to examine their safety. Subsequent evaluations examined expression levels and wound healing effects in human dermal fibroblasts (HDFs) using quantitative reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, and wound healing assays post-irradiation. Additionally, an in vivo study was conducted using a ultra violet (UV)-irradiated animal skin model to explore the impact of OLED exposure on dermal collagen density and wrinkles, employing skin replica and tissue staining techniques.

RESULTS

OLED irradiation had no significant morphological effects on human skin tissue, but caused a considerably higher expression of collagen than the control and LED-treated groups. Moreover, OLED irradiation reduced the expression levels of matrix metalloproteinases (MMPs) more effectively than did LED on HDFs. OLED irradiation group in HDFs had significantly higher expression levels of growth factors compared to the control group, but similar to those in the LED irradiation group. In addition, OLED irradiation on photo-aged animal skin model resulted in increased collagen fiber density in the dermis while reducing ultra violet radiation-mediated skin wrinkles and roughness, as shown in the skin replica.

CONCLUSION

This study established comparable effectiveness between OLED and LED irradiation in upregulating collagen and growth factor expression levels while downregulating MMP levels in vitro. In the UV-irradiated animal skin model, OLED exposure post UV radiation correlated with reduced skin wrinkles and augmented dermal collagen density. Accelerated wound recovery and demonstrated safety further underscore OLEDs' potential as a future PBM modality alongside LEDs, offering promise in the realms of skin rejuvenation and wound healing.

BMP4 up-regulated by 630 nm LED irradiation is associated with the amelioration of rheumatoid arthritis

Rheumatoid arthritis (RA) is caused by inflammatory response of joints with cartilage and damage of synovium and bone erosion. In our previous studies, it has showed that irradiation of 630 nm LED reduce inflammation of synovial fibroblasts and cartilage and bone destruction in RA. However, the key genes and mechanism in ameliorating RA by irradiation of 630 nm LED remains unknown. In this study, human fibroblast-like synoviocytes (FLS) cell line MH7A and primary human RA-FLSs were treated with TNF-α and 630 nm LED irradiation with the different energy density. The mRNA sequencing was performed to screen the differentially expressed genes (DEGs). In all datasets, 10 DEGs were identified through screening. The protein interaction network analysis showed that 8 out of the 10 DEGs interacted with each other including IL-6, CXCL2, CXCL3, MAF, PGF, IL-1RL1, RRAD and BMP4. This study focused on BMP4, which is identified as important morphogens in regulating the development and homeostasis. CCK-8 assay results showed that 630 nm LED irradiation did not affect the cell viability. The qPCR and ELISA results showed that TNF-α stimulation inhibited BMP4 mRNA and protein level and irradiation of 630 nm LED increased the BMP4 mRNA and protein level in MH7A cells. In CIA and transgenic hTNF-α mice models, H&E staining showed that irradiation of 630 nm LED decreased the histological scores assessed from inflammation and bone erosion, while BMP4 expression level was up-regulated after 630 nm LED irradiation. Pearson correlation analysis shown that BMP4 protein expression was negatively correlated with the histological score of CIA mice and transgenic hTNF-α mice. These results indicated that BMP4 increased by irradiation of 630 nm LED was associated with the amelioration of RA, which suggested that BMP4 may be a potential targeting gene for photobiomodulation.

The gut-joint axis mediates the TNF-induced RA process and PBMT therapeutic effects through the metabolites of gut microbiota

The gut-joint axis, one of the mechanisms that mediates the onset and progression of joint and related diseases through gut microbiota, and shows the potential as therapeutic target. A variety of drugs exert therapeutic effects on rheumatoid arthritis (RA) through the gut-joint axis. However, the anti-inflammatory and immunomodulatory effect of novel photobiomodulatory therapy (PBMT) on RA need further validation and the involvement of gut-joint axis in this process remains unknown. The present study demonstrated the beneficial effects of PBMT on RA, where we found the restoration of gut microbiota homeostasis, and the related key pathways and metabolites after PBMT. We also discovered that the therapeutic effects of PBMT on RA mainly through the gut-joint axis, in which the amino acid metabolites (Alanine and N-acetyl aspartate) play the key role and rely on the activity of metabolic enzymes in the target organs. Together, the results prove that the metabolites of amino acid from gut microbiota mediate the regulation effect on the gut-joint axis and the therapeutic effect on rheumatoid arthritis of PBMT.

Rheumatoid Arthritis and Reactive Oxygen Species: A Review

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that causes progressive joint damage and can lead to lifelong disability. Numerous studies support the hypothesis that reactive oxygen species (ROS) are associated with RA pathogenesis. Recent advances have clarified the anti-inflammatory effect of antioxidants and their roles in RA alleviation. In addition, several important signaling pathway components, such as nuclear factor kappa B, activator-protein-1, nuclear factor (erythroid-derived 2)-like 2/kelch-like associated protein, signal transducer and activator of transcription 3, and mitogen-activated protein kinases, including c-Jun N-terminal kinase, have been identified to be associated with RA. In this paper, we outline the ROS generation process and relevant oxidative markers, thereby providing evidence of the association between oxidative stress and RA pathogenesis. Furthermore, we describe various therapeutic targets in several prominent signaling pathways for improving RA disease activity and its hyper oxidative state. Finally, we reviewed natural foods, phytochemicals, chemical compounds with antioxidant properties and the association of microbiota with RA pathogenesis.

[Low level laser therapy: molecular mechanisms of anti-inflammatory and regenerative effects]

Laser therapy as a physiotherapeutic method has been successfully used for a long time in the treatment of various pathologies, but the action mechanisms of low level laser therapy (LLLT) remain understudied.

OBJECTIVE

To perform the analysis of published results of LLLT investigations, to describe the physical principles of photobiomodulation, its action mechanisms on various cells and tissues, therapeutic intervention and efficiency of the technique.

MATERIAL AND METHODS

The search of articles was done for the period from 2014 to 2022. The preference was given to the articles for the last 5 years in the PubMed database depending on keywords: low level laser therapy, photobiomodulation, exosomes, monocytes, macrophages.

RESULTS AND DISCUSSION

This article represents the current conceptions about the action mechanisms and reproduced effects of low level laser therapy, the photobiomodulation influence on the inflammation and reparative processes in human body by intervention on cells and their signal pathways. The discussion of research results and probable causes of conflicting data are performed, as well as the efficacy assessment of laser irradiation in different conditions and diseases is made.

CONCLUSION

Laser therapy has certain variety of advantages, among which: non-invasiveness and availability, long-term service of equipment, stable intensity of light radiation and the ability to use in various wavelength ranges. The technique efficacy was proven for a large number of diseases. However, for the successful application of photobiomodulation in clinical practice in current evidence-based medicine, additional investigations are necessary to determine the best dosimetric radiation parameters, as well as further study of action mechanisms on various human cells and tissues.

Low-level laser treatment promotes skin wound healing by activating hair follicle stem cells in female mice

The aim of the study was to explore the effect and mechanism of a low-level laser on hair follicle stem cells in full-thickness skin wound healing in mice. Full-thickness skin defects were generated by a 5-mm punch biopsy tool on the backs of depilated C57/BL6N mice, which were randomly divided thereafter into a low-dose laser treatment group (LLLT-Low), a high-dose laser treatment group (LLLT-High), and a control group (control). From the day of modeling to the day before the skin samples were taken, the wound area and wound edge of the mice in the LLLT-Low and LLLT-High groups were irradiated with a laser comb every 24 h, and the energy density was 1 J/cm2 and 10 J/cm2, respectively. The control group was irradiated with an ordinary fluorescent lamp. At 0, 3, 5, 10, and 14 days after modeling, pictures of each wound were taken, and the percent wound closure was analyzed. At 3, 5, 10, and 14 days after modeling, the samples were observed by hematoxylin and eosin (HE) and immunofluorescence (IF) staining. Whole transcriptome sequencing (RNA-Seq) was performed on the samples on day 10. Gene Ontology (GO) analysis was performed, and the results were validated by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). The analysis of the percent of wound closure showed that healing was accelerated (significantly from 5 to 10 days) in the LLLT-Low group, but there was no clear change in the LLLT-High group. HE staining showed that the LLLT-Low group had an increasing number of hair follicles and a tendency to migrate to the center of the wound. There was no significant increase in the number of hair follicles and no obvious migration in the LLLT-High group. Immunofluorescence staining showed that the total number of CK15 + hair follicle stem cells in the LLLT-Low group was higher than that in the control group and LLLT-High group at all time points. The number and farthest migration distance of CK15 + hair follicle stem cells increased significantly with time, and after 5 days, they were significantly higher than those in the control group and LLLT-High group. RNA-Seq and Western blot analysis showed that the expression of related genes in hair follicle stem cells, including CK15, in the LLLT-Low group was upregulated. GO analysis and ELISA showed that the expression of many cytokines, represented by IL34, in the LLLT-Low group was upregulated. Low-level laser treatment can promote the proliferation, differentiation, and migration of CK15 + hair follicle stem cells by upregulating the cytokine IL34, thereby promoting skin wound healing in mice.

Macrophages in heterotopic ossification: from mechanisms to therapy

Heterotopic ossification (HO) is the formation of extraskeletal bone in non-osseous tissues. It is caused by an injury that stimulates abnormal tissue healing and regeneration, and inflammation is involved in this process. It is worth noting that macrophages are crucial mediators of inflammation. In this regard, abundant macrophages are recruited to the HO site and contribute to HO progression. Macrophages can acquire different functional phenotypes and promote mesenchymal stem cell (MSC) osteogenic differentiation, chondrogenic differentiation, and angiogenesis by expressing cytokines and other factors such as the transforming growth factor-β1 (TGF-β1), bone morphogenetic protein (BMP), activin A (Act A), oncostatin M (OSM), substance P (SP), neurotrophin-3 (NT-3), and vascular endothelial growth factor (VEGF). In addition, macrophages significantly contribute to the hypoxic microenvironment, which primarily drives HO progression. Thus, these have led to an interest in the role of macrophages in HO by exploring whether HO is a "butterfly effect" event. Heterogeneous macrophages are regarded as the "butterflies" that drive a sequence of events and ultimately promote HO. In this review, we discuss how the recruitment of macrophages contributes to HO progression. In particular, we review the molecular mechanisms through which macrophages participate in MSC osteogenic differentiation, angiogenesis, and the hypoxic microenvironment. Understanding the diverse role of macrophages may unveil potential targets for the prevention and treatment of HO.

The Use of a Light-Emitting Diode Device for Neck Rejuvenation and Its Safety on Thyroid Glands

Home-use light-emitting diodes (LEDs) are attracting growing attention regarding their anti-aging effects. Although most previous studies on the use of LED devices as a form of low-level laser therapy reported no significant adverse events, questions regarding the safety of using a light source on secretory tissues have been raised. This study aimed to assess the safety and efficacy of a home-use LED device for neck skin rejuvenation, particularly regarding its effect on thyroid gland morphology and function. Thyroid function tests and ultrasonographic analyses showed no significant changes after 16 weeks of LED use. Evaluation using the Lemperle wrinkle scale and global improvement scales by both investigators and subjects showed significant improvement after 16 weeks of daily application, as well as 8 weeks after discontinuation. Biophysical parameters, such as hydration, elasticity, and density, also showed significant improvements. Hence, the long-term use of the LED device was safe and effective for neck rejuvenation, and showed no significant side effects on the adjacent thyroid and parathyroid glands.