Far-infrared therapy induces the nuclear translocation of PLZF which inhibits VEGF-induced proliferation in human umbilical vein endothelial cells

Therapeutic Potential of Infrared and Related Light Therapies in Metabolic Diseases

Infrared and related light therapies are gaining increasing interest due to their potential therapeutic properties in treating various health conditions, particularly metabolic diseases such as insulin resistance and type 2 diabetes. These diseases often coexist with dyslipidemia, obesity, non-alcoholic fatty liver disease, and cardiovascular complications. This review paper analyzes the impact, primarily of far-infrared light therapy (FIR), on improving endothelial function, reducing oxidative stress, and modulating inflammatory responses-key factors in metabolic diseases. Preliminary studies suggest that FIR may improve blood circulation, increase the secretion of VEGF, and enhance insulin sensitivity by alleviating inflammatory states and oxidative damage commonly associated with these diseases. In addition, FIR has been associated with potential benefits in blood pressure regulation and lipid metabolism, which could contribute to reduced cardiovascular risk. However, it is important to acknowledge that most current evidence is derived from preclinical models and small-scale clinical trials, limiting direct applicability to broader patient populations. Moreover, significant variability exists in exposure parameters and treatment protocols across studies. While FIR therapy holds potential as a complementary approach to the conventional management of metabolic diseases, careful monitoring is essential to mitigate potential adverse effects. Further well-designed, large-scale clinical trials are necessary to validate the therapeutic efficacy, optimize treatment parameters, and comprehensively assess the safety profile of FIR interventions in metabolic health.

Induction of apoptosis and hypoxic stress in malignant melanoma cells via graphene-mediated far-infrared radiation

BACKGROUND

Malignant melanoma (MM) is a highly aggressive skin tumor with a rising incidence and poor prognosis. Although current clinical treatments, including surgery, targeted therapy, immunotherapy, and radiotherapy, have shown some efficacy, therapeutic options remain limited for elderly patients and those with metastatic disease, highlighting the urgent need for novel therapeutic strategies. In recent years, the unique far-infrared radiation (FIR) properties of graphene have demonstrated potential applications in cancer treatment. However, the mechanisms underlying FIR's effects in MM therapy remain poorly understood.

METHODS

This study systematically evaluated the inhibitory effects of FIR on MM through in vitro cell experiments, animal models, and molecular mechanism analysis. First, the B16F10 melanoma cell line was used as the experimental model. The effects of FIR on cell proliferation, apoptosis, and the cell cycle were assessed using CCK-8 assays and flow cytometry, while RNA sequencing was conducted to analyze the associated signaling pathways. Second, specific caspase inhibitors were employed to further validate the mechanisms of FIR-induced apoptosis. Finally, a syngeneic tumor transplantation model in C57BL/6J mice was established to comfirm the anti-tumor efficacy of FIR in vivo, thereby comprehensively elucidating its anti-cancer mechanisms.

RESULTS

The results demonstrated that FIR significantly inhibits MM. In vitro experiments revealed that FIR treatment markedly suppressed B16F10 cell proliferation, induced apoptosis, caused G0/G1 phase cell cycle arrest, and downregulated the expression of hypoxia-related proteins such as HIF-1α. In animal studies, FIR significantly inhibited tumor growth. RNA sequencing revealed that FIR exerts its anti-cancer effects through multiple signaling pathways. Notably, the use of caspase inhibitors Z-DEVD-FMK and Z-LEHD-FMK, which specifically inhibit caspase-3 and caspase-9, respectively, can rescue cells from apoptosis induced by FIR treatment.

CONCLUSION

This study systematically elucidated that FIR exerts anti-tumor effects through multiple mechanisms, including inducing MM cell apoptosis, exacerbating hypoxic stress, and causing cell cycle arrest. The findings provide new insights and approaches for MM treatment and establish a theoretical foundation for the clinical application of FIR in cancer therapy.

The Effect of Increasing the Body's Core Temperature and Improving Blood Flow by Using Far-Infrared Rays Emitted from Functional Loess Bio-Balls

BACKGROUND

Low-energy far-infrared rays (FIRs) are widely used in the treatment of wounds, lymphedema, and various vascular diseases, and various types of products that emit infrared rays are being used at home for patients with blood flow-related diseases without experimental evidence.

METHODS

Blood flow and epidermal temperature were measured while applying conductive heat and FIRs via an electric mat (non-intervention) or a loess bio-ball mat (intervention).

RESULTS

In the control group (n = 30), there was a minimal change in blood flow and epidermal temperature in the right and left middle fingers (LMF, RMF) as the mat temperature gradually increased. In the experimental group (n = 30), when the mat temperature increased from 25 °C to 50 °C, the blood flow increased by 39.80% in the LMF and by 41.83% in the RMF. In addition, the epidermal temperature increased by 8.78% in the LMF and by 8.44% in the RMF.

CONCLUSIONS

The FIRs emitted from loess bio-balls can be applied to alleviate symptoms not only in patients with blood flow problems in medical settings but also in people who complain of discomfort due to blood flow disorders or cold hands and feet during their daily life and sleep.

Far-infrared irradiation inhibits proliferation of human upper airway epithelial cells via protein phosphatase 2A-promoted dephosphorylation of p70 S6 kinase

Far-infrared (FIR) ray, an invisible electromagnetic radiation with a wavelength of 3‒1000 μm, elicits various biological effects. Excessive proliferation of human upper airway epithelial cells (HUAEpCs) contributes to the development and exacerbation of nasal narrowing diseases, including nasal polyposis and chronic rhinosinusitis with nasal polyps (CRSwNP). Here, we investigated the molecular mechanisms through which FIR irradiation inhibits the proliferation of HUAEpCs. FIR irradiation significantly inhibited the proliferation of NCI-H292 cells without alteration in cell viability. The anti-proliferative effect of FIR radiation was accompanied by decreased phosphorylation of p70S6K at Thr389 (p-p70S6K-Thr389), without changes in the phosphorylation of mammalian target of rapamycin and adenosine monophosphate-activated protein kinase (AMPK). Overexpression of p70S6K-T389E mutant gene, not dominant negative-AMPKα1 gene, significantly reversed FIR irradiation-inhibited p-p70S6K-Thr389 and cell proliferation. Cotreatment with okadaic acid or knockdown of protein phosphatase 2A catalytic subunit (PP2Ac) gene expression significantly reversed FIR irradiation-decreased p-p70S6K-Thr389 and cell proliferation. FIR irradiation remarkably promoted the physical association of p70S6K and PP2Ac without change in total PP2Ac expression. Hyperthermal stimulus (39 °C) did not alter p-p70S6K-Thr389 and cell proliferation. In line with NCI-H292 cell results, FIR irradiation, not hyperthermal stimulus, significantly decreased p-p70S6K-Thr389 and cell proliferation in primary human nasal turbinate and polyp epithelial cells. These results demonstrated that FIR irradiation decreased the proliferation of HUAEpCs through PP2A-mediated inhibition of p70S6K phosphorylation, independent of its hyperthermal effect. Our data suggest that FIR therapy can be used to treat upper airway narrowing epithelial hyperplastic diseases, including nasal polyposis and CRSwNP.

Patch-Based Far-Infrared Radiation (FIR) Therapy Does Not Impact Cell Tracking or Motility of Human Melanoma Cells In Vitro

Far-Infrared Radiation (FIR) is emerging as a novel non-invasive tool for mitigating inflammation and oxidative stress, offering potential benefits for certain medical conditions such as cardiovascular disease and chronic inflammatory disorders. We previously demonstrated that the application of patch-based FIR therapy on human umbilical vein endothelial cells (HUVECs) reduced the expression of inflammatory biomarkers and the levels of reactive oxygen species (ROS). Several in vitro studies have shown the inhibitory effects of FIR therapy on cell growth in different cancer cells (including murine melanoma cells), mainly using the wound healing assay, without direct cell motility or tracking analysis. The main objective of the present study was to conduct an in-depth analysis of single-cell motility and tracking during the wound healing assay, using an innovative high-throughput technique in the human melanoma cell line M14/C2. This technique evaluates various motility descriptors, such as average velocity, average curvature, average turning angle, and diffusion coefficient. Our results demonstrated that patch-based FIR therapy did not impact cell proliferation and viability or the activation of mitogen-activated protein kinases (MAPKs) in the human melanoma cell line M14/C2. Moreover, no significant differences in cell motility and tracking were observed between control cells and patch-treated cells. Altogether, these findings confirm the beneficial effects of the in vitro application of patch-based FIR therapy in human melanoma cell lines, although such effects need to be confirmed in future in vivo studies.

Far-infrared radiation and its therapeutic parameters: A superior alternative for future regenerative medicine?

In future regenerative medicine, far-infrared radiation (FIR) may be an essential component of optical therapy. Many studies have confirmed or validated the efficacy and safety of FIR in various diseases, benefiting from new insights into FIR mechanisms and the excellent performance of many applications. However, the lack of consensus on the biological effects and therapeutic parameters of FIR limits its practical applications in the clinic. In this review, the definition, characteristics, and underlying principles of the FIR are systematically illustrated. We outline the therapeutic parameters of FIR, including the wavelength range, power density, irradiation time, and distance. In addition, the biological effects, potential molecular mechanisms, and preclinical and clinical applications of FIR are discussed. Furthermore, the future development and applications of FIR are described in this review. By applying optimal therapeutic parameters, FIR can influence various cells, animal models, and patients, eliciting diverse underlying mechanisms and offering therapeutic potential for many diseases. FIR could represent a superior alternative with broad prospects for application in future regenerative medicine.

Graphene Far-Infrared Irradiation Can Effectively Relieve the Blood Pressure Level of Rat Untr-HT in Primary Hypertension

Graphene, when electrified, generates far-infrared radiation within the wavelength range of 4 μm to 14 μm. This range closely aligns with the far-infrared band (3 μm to 15 μm), which produces unique physiological effects. Contraction and relaxation of vascular smooth muscle play a significant role in primary hypertension, involving the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate pathway and the renin-angiotensin-aldosterone system. This study utilized spontaneously hypertensive rats (SHRs) as an untr-HT to investigate the impact of far-infrared radiation at specific wavelengths generated by electrified graphene on vascular smooth muscle and blood pressure. After 7 weeks, the blood pressure of the untr-HT group rats decreased significantly with a notable reduction in the number of vascular wall cells and the thickness of the vascular wall, as well as a decreased ratio of vessel wall thickness to lumen diameter. Additionally, blood flow perfusion significantly increased, and the expression of F-actin in vascular smooth muscle myosin decreased significantly. Serum levels of angiotensin II (Ang-II) and endothelin 1 (ET-1) were significantly reduced, while nitric oxide synthase (eNOS) expression increased significantly. At the protein level, eNOS expression decreased significantly, while α-SMA expression increased significantly in aortic tissue. At the gene level, expressions of eNOS and α-SMA in aortic tissue significantly increased. Furthermore, the content of nitric oxide (NO) in the SHR's aortic tissue increased significantly. These findings confirm that graphene far-infrared radiation enhances microcirculation, regulates cytokines affecting vascular smooth muscle contraction, and modifies vascular morphology and smooth muscle phenotype, offering relief for primary hypertension.

A Graphene Composite Film Based Wearable Far-Infrared Therapy Apparatus (GRAFT) for Effective Prevention of Postoperative Peritoneal Adhesion

Postoperative peritoneal adhesion (PPA) is the most frequent complication after abdominal surgery. Current anti-adhesion strategies largely rely on the use of physical separating barriers creating an interface blocking peritoneal adhesion, which cannot reduce inflammation and suffers from limited anti-adhesion efficacy with unwanted side effects. Here, by exploiting the alternative activated macrophages to alleviate inflammation in adhesion development, a flexible graphene-composite-film (F-GCF) generating far-infrared (FIR) irradiation that effectively modulates the macrophage phenotype toward the anti-inflammatory M2 type, resulting in reduced PPA formation, is designed. The anti-adhesion effect of the FIR generated by F-GCF is determined in the rat abdominal wall abrasion-cecum defect models, which exhibit reduced incidence and area of PPA by 67.0% and 92.1% after FIR treatment without skin damage, significantly superior to the clinically used chitosan hydrogel. Notably, within peritoneal macrophages, FIR reduces inflammation reaction and promotes tissue plasminogen activator (t-PA) level via the polarization of peritoneal macrophages through upregulating Nr4a2 expression. To facilitate clinical use, a wirelessly controlled, wearable, F-GCF-based FIR therapy apparatus (GRAFT) is further developed and its remarkable anti-adhesion ability in the porcine PPA model is revealed. Collectively, the physical, biochemical, and in vivo preclinical data provide compelling evidence demonstrating the clinical-translational value of FIR in PPA prevention.

A Phase 1 randomized, open-label clinical trial to evaluate the effect of a far-infrared emitting patch on local skin perfusion, microcirculation and oxygenation

Far-infrared radiation (FIR) has been investigated for reduction of pain and improvement of dermal blood flow. The FIRTECH patch is a medical device designed to re-emit FIR radiated by the body. This phase 1 study was conducted to evaluate the local effects of the FIRTECH patch on local skin perfusion, microcirculation and oxygenation. This prospective, randomized, open-label, parallel designed study admitted 20 healthy participants to a medical research facility for treatment for 31 h on three anatomical locations. During treatment, imaging assessments consisting of laser speckle contrast imaging, near-infrared spectroscopy, side-stream dark-field microscopy, multispectral imaging and thermography were conducted regularly on patch-treated skin and contralateral non-treated skin. The primary endpoint was baseline perfusion increase during treatment on the upper back. Secondary endpoints included change in baseline perfusion, oxygen consumption and temperature of treated versus untreated areas. The primary endpoint was not statistically significantly different between treated and non-treated areas. The secondary endpoints baseline perfusion on the forearm (least square means [LSMs] difference 2.63 PU, 95% CI: 0.97, 4.28), oxygen consumption (LSMs difference: 0.42 arbitrary units [AUs], 95% CI: 0.04, 0.81) and skin temperature (LSMs difference 0.35°C, 95% CI: 0.16, 0.6) were statistically significantly higher in treated areas. Adverse events observed during the study were mild and transient. The vascular response to the FIRTECH patch was short-lived suggesting a non-thermal vasodilatory effect of the patch. The FIRTECH patch was well tolerated, with mild and transient adverse events observed during the study. These results support the therapeutic potential of FIR in future investigations.

Enhanced far infrared emissivity, UV protection and near-infrared shielding of polypropylene composites via incorporation of natural mineral for functional fabric development

Far infrared radiation in the range of 4-20 µm has been showed to have biological and health benefits to the human body. Therefore, incorporating far-infrared emissivity additives into polymers and/or fabrics hold promise for the development of functional textiles. In this study, we incorporated nine types of natural minerals into polypropylene (PP) film and examined their properties to identify potential candidates for functional textiles and apparels. The addition of 2% mineral powders into PP film increased the far-infrared emissivity (5-14 µm) by 7.65%-14.48%. The improvement in far-infrared emissivity within the range of 5-14 µm, which overlaps with the peak range of human skin radiation at 8-14 µm, results in increased absorption efficiency, and have the potential to enhance thermal and biological effects. Moreover, the incorporation of mineral powders in PP films exhibited favorable ultraviolet (UV) protection and near-infrared (NIR) shielding properties. Two films, specifically those containing red ochre and hematite, demonstrated excellent UV protection with a UPF rating of 50+ and blocked 99.92% and 98.73% of UV radiation, respectively. Additionally, they showed 95.2% and 93.2% NIR shielding properties, compared to 54.1% NIR shielding properties of PP blank films. The UV protection and NIR shielding properties offered additional advantages for the utilization of polymer composite with additives in the development of sportswear and other outdoor garments. The incorporation of minerals could absorb near-IR radiation and re-emit them at longer wavelength in the mid-IR region. Furthermore, the incorporation of minerals significantly improved the heat retention of PP films under same heat radiation treatment. Notably, films with red ochre and hematite exhibited a dramatic temperature increase, reaching 2.5 and 3.2 times the temperature increase of PP films under same heat radiation treatment, respectively (46.8 °C and 59.9 °C higher than the temperature increase of 20.9 °C in the PP film). Films with additives also demonstrated lower thermal effusivity than PP blank films, indicating superior heat insulation properties. Therefore, polypropylene films with mineral additives, particularly those containing red ochre and hematite, showed remarkable heat capacity, UV-protection, NIR-shielding properties and enhanced far infrared emissivity, making them promising candidates for the development of functional textiles.

Far-Infrared Irradiation Decreases Proliferation in Basal and PDGF-Stimulated VSMCs Through AMPK-Mediated Inhibition of mTOR/p70S6K Signaling Axis

BACKGROUND

Far-infrared (FIR) irradiation has been reported to improve diverse cardiovascular diseases, including heart failure, hypertension, and atherosclerosis. The dysregulated proliferation of vascular smooth muscle cells (VSMCs) is well established to contribute to developing occlusive vascular diseases such as atherosclerosis and in-stent restenosis. However, the effects of FIR irradiation on VSMC proliferation and the underlying mechanism are unclear. This study investigated the molecular mechanism through which FIR irradiation inhibited VSMC proliferation.

METHODS

We performed cell proliferation and cell death assay, adenosine 5'-triphosphate (ATP) assay, inhibitor studies, transfection of dominant negative (dn)-AMP-activated protein kinase (AMPK) α1 gene, and western blot analyses. We also conducted confocal microscopic image analyses and ex vivo studies using isolated rat aortas.

RESULTS

FIR irradiation for 30 minutes decreased VSMC proliferation without altering the cell death. Furthermore, FIR irradiation accompanied decreases in phosphorylation of the mammalian target of rapamycin (mTOR) at Ser2448 (p-mTOR-Ser2448) and p70 S6 kinase (p70S6K) at Thr389 (p-p70S6K-Thr389). The phosphorylation of AMPK at Thr172 (p-AMPK-Thr172) was increased in FIR-irradiated VSMCs, which was accompanied by a decreased cellular ATP level. Similar to in vitro results, FIR irradiation increased p-AMPK-Thr172 and decreased p-mTOR-Ser2448 and p-p70S6K-Thr389 in isolated rat aortas. Pre-treatment with compound C, a specific AMPK inhibitor, or ectopic expression of dn-AMPKα1 gene, significantly reversed FIR irradiation-decreased VSMC proliferation, p-mTOR-Ser2448, and p-p70S6K-Thr389. On the other hand, hyperthermal stimulus (39°C) did not alter VSMC proliferation, cellular ATP level, and AMPK/mTOR/p70S6K phosphorylation. Finally, FIR irradiation attenuated platelet-derived growth factor (PDGF)-stimulated VSMC proliferation by increasing p-AMPK-Thr172, and decreasing p-mTOR-Ser2448 and p-p70S6K-Thr389 in PDGF-induced in vitro atherosclerosis model.

CONCLUSION

These results show that FIR irradiation decreases the basal and PDGF-stimulated VSMC proliferation, at least in part, by the AMPK-mediated inhibition of mTOR/p70S6K signaling axis irrespective of its hyperthermal effect. These observations suggest that FIR therapy can be used to treat arterial narrowing diseases, including atherosclerosis and in-stent restenosis.

Effect of far-infrared therapy device on arteriovenous fistula maturation and lifespan in hemodialysis patients: a randomized controlled clinical trial

Introduction

Arteriovenous fistula (AVF) is the first choice of vascular access for hemodialysis treatment, and its surgical maturity rate is not high, and its postoperative complications (mostly stenosis) significantly shorten its life. At present, there are few studies on treatment methods to improve the maturity and survival of AVF. In this study, the effect of far infrared therapy (FIR) on the maturity and longevity of arteriovenous fistula in hemodialysis patients was discussed, and the protective mechanism of AVF induced by FIR therapy was explored, aiming at exploring a new treatment method.

Methods

The hemodialysis patients admitted to the 900th Hospital of the Chinese Joint Logistics Support Force of the People's Liberation Army from January 2021 to April 2023 were randomly divided into control group and intervention group, with 40 cases in each group. Among them, the control group was coated with mucopolysaccharide polysulfonate cream; Intervention group: The patients were treated with mucopolysaccharide polysulfonate cream and far infrared radiation at the same time. After 3 months' intervention, the arteriovenous fistula (vein diameter, mature time of arteriovenous fistula, blood flow controlled by pump during dialysis, blood flow of brachial artery during dialysis and the occurrence of complications of internal fistula (oozing, occlusion and infection) and the pain score (numerical rating scale, NRS) of the two groups were compared, and the curative effects were compared.

Results

There was no significant difference in general data between the two groups (P > 0.05), which indicated that the study was comparable. After 3 months' intervention, the vein diameter, pump-controlled blood flow and brachial artery blood flow in the intervention group were significantly higher than those in the control group (P < 0.05). And the maturity time, NRS score and complication rate of arteriovenous fistula were significantly lower than those of the control group (P < 0.05). The primary patency rate of AVF in the intervention group was higher than that in the control group, and the overall patency rate between the two groups was statistically significant (P < 0.05).

Conclusions

As a promising new treatment method, far infrared therapy can effectively promote the maturity of AVF, increase venous diameter, pump controlled blood flow during dialysis, brachial artery blood flow during dialysis, and prolong the service life of AVF.

Enhanced ZBTB16 Levels by Progestin-Only Contraceptives Induces Decidualization and Inflammation

Progestin-only long-acting reversible-contraceptive (pLARC)-exposed endometria displays decidualized human endometrial stromal cells (HESCs) and hyperdilated thin-walled fragile microvessels. The combination of fragile microvessels and enhanced tissue factor levels in decidualized HESCs generates excess thrombin, which contributes to abnormal uterine bleeding (AUB) by inducing inflammation, aberrant angiogenesis, and proteolysis. The- zinc finger and BTB domain containing 16 (ZBTB16) has been reported as an essential regulator of decidualization. Microarray studies have demonstrated that ZBTB16 levels are induced by medroxyprogesterone acetate (MPA) and etonogestrel (ETO) in cultured HESCs. We hypothesized that pLARC-induced ZBTB16 expression contributes to HESC decidualization, whereas prolonged enhancement of ZBTB16 levels triggers an inflammatory milieu by inducing pro-inflammatory gene expression and tissue-factor-mediated thrombin generation in decidualized HESCs. Thus, ZBTB16 immunostaining was performed in paired endometria from pre- and post-depo-MPA (DMPA)-administrated women and oophorectomized guinea pigs exposed to the vehicle, estradiol (E2), MPA, or E2 + MPA. The effect of progestins including MPA, ETO, and levonorgestrel (LNG) and estradiol + MPA + cyclic-AMP (E2 + MPA + cAMP) on ZBTB16 levels were measured in HESC cultures by qPCR and immunoblotting. The regulation of ZBTB16 levels by MPA was evaluated in glucocorticoid-receptor-silenced HESC cultures. ZBTB16 was overexpressed in cultured HESCs for 72 h followed by a ± 1 IU/mL thrombin treatment for 6 h. DMPA administration in women and MPA treatment in guinea pigs enhanced ZBTB16 immunostaining in endometrial stromal and glandular epithelial cells. The in vitro findings indicated that: (1) ZBTB16 levels were significantly elevated by all progestin treatments; (2) MPA exerted the greatest effect on ZBTB16 levels; (3) MPA-induced ZBTB16 expression was inhibited in glucocorticoid-receptor-silenced HESCs. Moreover, ZBTB16 overexpression in HESCs significantly enhanced prolactin (PRL), insulin-like growth factor binding protein 1 (IGFBP1), and tissue factor (F3) levels. Thrombin-induced interleukin 8 (IL-8) and prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA levels in control-vector-transfected HESCs were further increased by ZBTB16 overexpression. In conclusion, these results supported that ZBTB16 is enhanced during decidualization, and long-term induction of ZBTB16 expression by pLARCs contributes to thrombin generation through enhancing tissue factor expression and inflammation by enhancing IL-8 and PTGS2 levels in decidualized HESCs.

Physical properties and biological effects of ceramic materials emitting infrared radiation for pain, muscular activity, and musculoskeletal conditions

BACKGROUND

Up to 33% of the general population worldwide suffer musculoskeletal conditions, with low back pain being the single leading cause of disability globally. Multimodal therapeutic options are available to relieve the pain associated with muscular disorders, including physical, complementary, and pharmacological therapies. However, existing interventions are not disease modifying and have several limitations.

METHOD

Literature review.

RESULTS

In this context, the use of nonthermal infrared light delivered via patches, fabrics, and garments containing infrared-emitting bioceramic minerals have been investigated. Positive effects on muscular cells, muscular recovery, and reduced inflammation and pain have been reported both in preclinical and clinical studies. There are several hypotheses on how infrared may contribute to musculoskeletal pain relief, however, the full mechanism of action remains unclear. This article provides an overview of the physical characteristics of infrared radiation and its biological effects, focusing on those that could potentially explain the mechanism of action responsible for the relief of musculoskeletal pain.

CONCLUSIONS

Based on the current evidence, the following pathways have been considered: upregulation of endothelial nitric oxide synthase, increase in nitric oxide bioavailability, anti-inflammatory effects, and reduction in oxidative stress.

Choroidal arteriovenous anastomoses: a hypothesis for the pathogenesis of central serous chorioretinopathy and other pachychoroid disease spectrum abnormalities

The pachychoroid disease spectrum (PDS) includes several chorioretinal diseases that share specific choroidal abnormalities. Although their pathophysiological basis is poorly understood, diseases that are part of the PDS have been hypothesized to be the result of venous congestion. Within the PDS, central serous chorioretinopathy is the most common condition associated with vision loss, due to an accumulation of subretinal fluid in the macula. Central serous chorioretinopathy is characterized by distinct risk factors, most notably a high prevalence in males and exposure to corticosteroids. Interestingly, sex differences and corticosteroids are also strongly associated with specific types of arteriovenous anastomoses in the human body, including dural arteriovenous fistula and surgically created arteriovenous shunts. In this manuscript, we assess the potential of such arteriovenous anastomoses in the choroid as a causal mechanism of the PDS. We propose how this may provide a novel unifying concept on the pathophysiological basis of the PDS, and present cases in which this mechanism may play a role.

Pathogenic Risk Factors and Associated Outcomes in the Bullous Variant of Central Serous Chorioretinopathy

PURPOSE

To compare the clinical features, treatments, and outcomes between bullous and chronic variants of central serous chorioretinopathy (CSC).

DESIGN

Retrospective, observational case series.

PARTICIPANTS

Sixty-two eyes of 44 patients with bullous-variant CSC (bvCSC) and 97 eyes of 85 patients with nonbullous CSC.

METHODS

We conducted a national survey between September 1, 2020, and March 31, 2021, of members of the Korean Retina Society and obtained data of patients with bvCSC from 11 retinal centers. A comparator group comprised consecutive chronic CSC patients without bullous detachment.

MAIN OUTCOME MEASURES

Baseline demographics and patient characteristics were compared between groups. Secondary outcomes included factors associated with visual prognosis within the bvCSC group.

RESULTS

Compared with the nonbullous CSC group, the bvCSC group presented at a younger age (49 vs. 52 years; P = 0.047) and with more bilateral involvement (41% vs. 14%; P < 0.001). Systemic corticosteroid use was more prevalent in the bvCSC group, both in terms of any exposure (50% vs. 20%; P = 0.001) and long-term exposure (36% vs. 9%; P <  0.001). The bvCSC group had distinct imaging features (all P < 0.05): retinal folding (64% vs. 1%), subretinal fibrin (75% vs. 13%), multiple retinal pigment epithelium tears (24% vs. 2%), and multifocal fluorescein leakages with terminal telangiectasia (36% vs. 1%). Although bvCSC patients had worse vision at diagnosis (20/80 vs. 20/44; P =  0.003), treatment response was more robust (fluid resolution by final follow-up, 84% vs. 68%; P = 0.034) even with conservative management, resulting in similar final vision (20/52 vs. 20/45; P =  0.52). History of kidney-related (odds ratio [OR] 5.4; 95% confidence interval [CI] 1.3-18.5; P =  0.045) and autoimmune/rheumatoid diseases (OR 25.4, 95% CI 2.8-195.0; P =  0.004) showed associations with the bvCSC group. Apart from vision at diagnosis (OR 0.1, 95% CI 0.05-0.36; P  <  0.001), a history of renal transplantation was most predictive of visual prognoses for bvCSC eyes (OR 0.2, 95% CI 0.04-0.75; P  =  0.020).

CONCLUSIONS

Bullous-variant CSC may be associated with pathogenic risk factors based on underlying medical conditions and systemic corticosteroid use. Poor vision at diagnosis and history of renal transplantation were associated with poor visual outcome.

Skin Minerals: Key Roles of Inorganic Elements in Skin Physiological Functions

As odd as it may seem at first glance, minerals, it is what we are all about…or nearly. Although life on Earth is carbon-based, several other elements present in the planet’s crust are involved in and often indispensable for functioning of living organisms. Many ions are essential, and others show supportive and accessory qualities. They are operative in the skin, supporting specific processes related to the particular situation of this organ at the interface with the environment. Skin bioenergetics, redox balance, epidermal barrier function, and dermal remodeling are amongst crucial activities guided by or taking advantage of mineral elements. Skin regenerative processes and skin ageing can be positively impacted by adequate accessibility, distribution, and balance of inorganic ions.

The Cortisol Response of Male and Female Choroidal Endothelial Cells: Implications for Central Serous Chorioretinopathy

CONTEXT

Central serous chorioretinopathy (CSC) is a severe ocular disease characterized by fluid accumulation under the retina and abnormalities in the underlying vascular layer, the choroid. CSC has a striking prevalence in males of 80% to 90% of total patients. Corticosteroids are the most pronounced extrinsic risk factor for CSC. Choroidal endothelial cells (CECs) are important for the vascular integrity of the choroid, but the effects of corticosteroid effects in these cells are unknown.

OBJECTIVE

We aimed to reveal the potential steroidal contribution to CSC.

METHOD

We characterized the expression of the glucocorticoid, mineralocorticoid, and androgen receptor in the human choroid using immunohistochemistry. Using RNA-sequencing, we describe the cortisol response in human CECs derived from 5 male and 5 female postmortem donors.

RESULTS

The glucocorticoid receptor was highly expressed in the human choroid, whereas no to minimal expression of the mineralocorticoid and androgen receptors was observed. The extensive transcriptional response to cortisol in human primary cultured CECs showed interindividual differences but very few sex differences. Several highly regulated genes such as ZBTB16 (log2 fold change males 7.9; females 6.2) provide strong links to choroidal vascular regulation.

CONCLUSIONS

The glucocorticoid receptor predominantly mediates the response to cortisol in human CECs. Interindividual differences are an important determinant regarding the cortisol response in human cultured CECs, whereas intrinsic sex differences appear less pronounced. The marked response of particular target genes in endothelial cells to cortisol, such as ZBTB16, warrants further investigation into their potential role in the pathophysiology of CSC and other vascular conditions.

The Yin and Yang dualistic features of autophagy in thermal burn wound healing

Burn healing should be regarded as a dynamic process consisting of two main, interrelated phases: (a) the inflammatory phase when neutrophils and monocytes infiltrate the injury site, through localized vasodilation and fluid extravasation, and (b) the proliferative-remodeling phase, which represents a key event in wound healing. In the skin, both canonical autophagy (induced by starvation, oxidative stress, and environmental aggressions) and non-canonical or selective autophagy have evolved to play a discrete, but, essential, “housekeeping” role, for homeostasis, immune tolerance, and survival. Experimental data supporting the pro-survival roles of autophagy, highlighting its Yang, luminous and positive feature of this complex but insufficient explored molecular pathway, have been reported. Autophagic cell death describes an “excessive” degradation of important cellular components that are necessary for normal cell function. This deadly molecular mechanism brings to light the darker, concealed, Yin feature of autophagy. Autophagy seems to perform dual, conflicting roles in the angiogenesis context, revealing once again, its Yin–Yang features. Autophagy with its Yin–Yang features remains the shadow player, able to decide quietly whether the cell survives or dies.

Germanium-Titanium-π Polymer Composites as Functional Textiles for Clinical Strategy to Evaluate Blood Circulation Improvement and Sexual Satisfaction

By continuously enhancing the blood flow, far-infrared (FIR) textile is anticipated to be a potential non-pharmacological therapy in patients with peripheral vascular disorders, for instance, patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) and experiencing vasculogenic erectile dysfunction (VED). Hence, we manufactured a novel polymer composite, namely, germanium-titanium-π (Ge-Ti-π) textile and aimed to evaluate its characteristics and quality. We also investigated the immediate and long-term effects of the textile on patients with ESRD undergoing HD and experiencing VED. The Ge-Ti-π textile was found to have 0.93 FIR emissivity, 3.05 g/d strength, and 18.98% elongation. The results also showed a 51.6% bacteria reduction and negative fungal growth. On application in patients receiving HD, the Ge-Ti-π textile significantly reduced the limb numbness/pain (p < 0.001) and pain score on the visual analog scale (p < 0.001). Moreover, the Doppler ultrasound assessment data indicated a significant enhancement of blood flow in the right hand after 1 week of Ge-Ti-π textile treatment (p < 0.041). In VED patients, the Ge-Ti-π underpants treatment significantly improved the quality of sexual function and increased the average penile blood flow velocity after 3 months of the treatment. Our study suggests that the Ge-Ti-π textile could be beneficial for patients with blood circulation disorders.

Far infrared irradiation suppresses experimental arthritis in rats by down-regulation of genes involved inflammatory response and autoimmunity

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FIR treatment improved adjuvant arthritis in rats.

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FIR exposure inhibited the inflammatory genes expression of synovial tissues in AIA rats.

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FIR exposure down-regulated inflammatory genes expression mainly through transcription factors AP-1, CEBPα, CEBPβ, c-Fos, GR, HNF-3β, USF-1, and USF-2.

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FIR irradiation may exhibit anti-arthritic effects through inactivation of the MAPK, PI3K-Akt, and NF-κB signaling pathways.

Introduction

Objectives

Methods

Results

Conclusion

The Effect of Far-Infrared Therapy on the Peritoneal Membrane Transport Characteristics of Uremic Patients Undergoing Peritoneal Dialysis: An Open-Prospective Proof-of-Concept Study

Long-term peritoneal dialysis (PD) can lead to detrimental changes in peritoneal membrane function, which may be related to the accumulation of glucose degradation products. A previous study demonstrated that 6 months of far-infrared (FIR) therapy may decrease glucose degradation products in PD dialysate. Due to limited literature on this matter, this study aims to investigate the effect of FIR therapy on the peritoneal membrane transport characteristics of PD patients. Patients were grouped according to baseline peritoneal transport status: lower transporters (low and low-average) and higher transporters (high-average and high). Both groups underwent 40 min of FIR therapy twice daily for 1 year. In lower transporters, FIR therapy increased weekly dialysate creatinine clearance (6.91 L/wk/1.73 m²; p = 0.04) and D/P creatinine (0.05; p = 0.01). In higher transporters, FIR therapy decreased D/P creatinine (−0.05; p = 0.01) and increased D/D0 glucose (0.05; p = 0.006). Fifty percent of high transporter patients shifted to high-average status after FIR therapy. FIR therapy may decrease D/P creatinine for patients in the higher transporter group and cause high transporters to shift to high-average status, which suggests the potential of FIR therapy in improving peritoneal membrane function in PD patients.

Infrared radiation from cage bedding moderates rat inflammatory and autoimmune responses in collagen-induced arthritis

The development of collagen type II (CII)-induced arthritis (CIA), a model of rheumatoid arthritis, in rats housed in cages with bedding composed of Celliant fibres containing ceramic particles, which absorb body heat and re-emit the energy back to the body in the form of infrared radiation (+IRF rats), and those housed in cages with standard wooden shaving bedding (-IRF control rats) was examined. The appearance of the first signs of CIA was postponed, while the disease was milder (judging by the arthritic score, paw volume, and burrowing behaviour) in +IRF compared with -IRF rats. This correlated with a lower magnitude of serum anti-CII IgG antibody levels in +IRF rats, and lower production level of IL-17, the Th17 signature cytokine, in cultures of their paws. This could be partly ascribed to impaired migration of antigen-loaded CD11b + dendritic cells and their positioning within lymph nodes in +IRF rats reflecting diminished lymph node expression of CCL19 /CCL21. Additionally, as confirmed in rats with carrageenan-induced paw inflammation (CIPI), the infrared radiation from Celliant fibres, independently from immunomodulatory effects, exerted anti-inflammatory effects (judging by a shift in pro-inflammatory mediator to anti-inflammatory/immunoregulatory mediator ratio towards the latter in paw cultures) and ameliorated burrowing behaviour in CIA rats.

The effectiveness of far-infrared irradiation on foot skin surface temperature and heart rate variability in healthy adults over 50 years of age: A randomized study

BACKGROUND

Far-infrared irradiation (FIR) is used in the medical field to improve wound healing, hemodialysis with peripheral artery occlusive disease, and osteoarthritis but seldom used in ameliorating poor lower extremity circulation. The purpose of this study was to evaluate the effect of FIR on changes in foot skin surface temperature (FSST) and autonomic nerve system (ANS) activity to evaluate its effectiveness in improving lower limb circulation.

METHODS

A randomized controlled study was conducted. Subjects (n = 44), all over the age of 50 years and satisfying the inclusion criteria, were randomly allocated into 2 groups. The intervention group received FIR on a lower limb for 40 minutes and the control group received no intervention. Left big toe (LBT), right big toe (RBT), left foot dorsal (LFD), right foot dorsal (RFD) surface skin temperature, autonomic nervous activity, and blood pressure were assessed.

RESULTS

The main results were skin surface temperature at the LBT increased from 30.8 ± 0.4°C to 34.8 ± 0.4°C, at RBT increased from 29.6 ± 0.4°C to 35.3 ± 0.4°C and LFD increased from 31.9 ± 0.3°C to 36.4 ± 0.4°C, RFD increased from 30.7 ± 0.3°C to 37.7 ± 0.2°C. FIR caused a significant increase of the FSST ranging in a 4°C to 7°C increase after 40 minutes irradiation (P < .001). The ANS low-frequency (LF) and high-frequency (HF) activity showed a statistically significant increase in the FIR group (P < .05) but not the LF/HF ratio.

CONCLUSION

FIR significantly increased the FSST from between 4°C and 7°C after 40 minutes irradiation, which might improve lower extremity circulation and regulation of ANS activity.

Evaluating the Far-Infrared Radiation Bioeffects on Micro Vascular Dysfunction, Nervous System, and Plantar Pressure in Diabetes Mellitus

The most frequent clinical complication is diabetes. Diabetes is characterized by elevated blood glucose levels resulting in sensory nerve damage or lesions. Diabetic foot wounds are often slow to heal and require medical attention and monitoring. This study evaluates the effect of far-infrared radiation on the microcirculation and plantar pressure in the diabetic foot. Ten diabetics and 4 nondiabetics were recruited in this study. The diabetic group was examined before and after the intervention in each month for 3 consecutive months. Four nondiabetic groups were also measured before and after the intervention for 2 weeks in each month. The surface temperature and blood flow in the diabetic foot was significantly improved (temperature: 32.1 ± 2.3°C vs 33.5 ± 2.2°C, P < .05; blood flow image: 118.3 ± 58.1 PU [perfusion unit] vs 50.4 ± 4.3 PU, P < .05). The sympathetic nerve activity index LF also increased from 40.8 ± 18.6% to 61.8 ± 13.5% (P = .07) in the second month. Plantar pressure tended to increase in the third month. This might indicate that far-infrared radiation could affect the mechanical properties of the plantar foot soft tissue. These results indicated that the effects of far-infrared radiation would improve blood circulation and change the soft tissue properties in the diabetic foot.

Detecting the limits of the biological effects of far-infrared radiation on epithelial cells

Far-infrared radiation (FIR) exerts numerous beneficial effects on health and cell physiology. Recent studies revealed that the biological effects of FIR are independent of thermal effects. There is no proper method for measuring the parameters of the non-thermal biological effects of FIR, which limits its biomedical application. In this study, we established a cell detection platform using epithelial cell migration to measure the limits of the biological effects of FIR. FIR promoted the migration of rat renal tubular epithelial cells as revealed by our standardized detection method. We defined the ratio of the FIR-promoted migration area to the migration area of the control group as the FIR biological index (FBI). An increase of the FBI was highly associated with FIR-promoted mitochondrial function. Through FBI detection, we revealed the limits of the biological effects of FIR, including effective irradiation time, wavelengths, and temperature. FBI detection can be used to clarify important parameters of the biological effects of FIR in biomedical studies and health industry applications.

Expression of the PTEN/FOXO3a/PLZF signalling pathway in pancreatic cancer and its significance in tumourigenesis and progression

Pancreatic cancer (PC) is one of the most lethal gastrointestinal malignancies. The PTEN/AKT signalling pathway is closely related to the tumourigenesis and progression of PC. The downstream effectors, FOXO3a, PLZF and VEGF, are reported to be involved in angiogenesis, lymph node metastasis and poor survival in PC. By using tissue microarrays and immunohistochemistry, we found, that PTEN, FOXO3a and PLZF expression was significantly decreased in PC specimens compared with that in chronic pancreatitis (CP) specimens, while VEGF expression was significantly increased. Furthermore, the expression of PTEN was positively correlated with that of FOXO3a and PLZF but negatively correlated with that of VEGF. Our results suggest that the PTEN/FOXO3a/PLZF signalling pathway may negatively regulate VEGF expression in PC. Through clinical analysis of 69 PC patients, PTEN, FOXO3a and PLZF expression was found to be significantly decreased in specimens from PC patients with lymph node metastasis and poor prognosis, while VEGF expression was significantly increased. Taken together, these reaults suggest that the PTEN/FOXO3a/PLZF signalling pathway may be capable of inhibiting growth and metastasis in PC by regulating VEGF-mediated angiogenesis, which requires further in vivo and in vitro studies and can potentially be a therapeutic target for PC.

Far-infrared radiation stimulates platelet-derived growth factor mediated skeletal muscle cell migration through extracellular matrix-integrin signaling

Despite increased evidence of bio-activity following far-infrared (FIR) radiation, susceptibility of cell signaling to FIR radiation-induced homeostasis is poorly understood. To observe the effects of FIR radiation, FIR-radiated materials-coated fabric was put on experimental rats or applied to L6 cells, and microarray analysis, quantitative real-time polymerase chain reaction, and wound healing assays were performed. Microarray analysis revealed that messenger RNA expressions of rat muscle were stimulated by FIR radiation in a dose-dependent manner in amount of 10% and 30% materials-coated. In 30% group, 1,473 differentially expressed genes were identified (fold change [FC] > 1.5), and 218 genes were significantly regulated (FC > 1.5 and p < 0.05). Microarray analysis showed that extracellular matrix (ECM)-receptor interaction, focal adhesion, and cell migration-related pathways were significantly stimulated in rat muscle. ECM and platelet-derived growth factor (PDGF)-mediated cell migration-related genes were increased. And, results showed that the relative gene expression of actin beta was increased. FIR radiation also stimulated actin subunit and actin-related genes. We observed that wound healing was certainly promoted by FIR radiation over 48 h in L6 cells. Therefore, we suggest that FIR radiation can penetrate the body and stimulate PDGF-mediated cell migration through ECM-integrin signaling in rats.

Autophagy promotes angiogenesis via AMPK/Akt/mTOR signaling during the recovery of heat-denatured endothelial cells

Our previous study demonstrated that angiogenesis increased during the recovery of heat-denatured endothelial cells. However, the mechanism is still unclear. This study aimed to investigate the relation of autophagy and angiogenesis during the recovery of heat-denatured endothelial cells. A rat deep partial-thickness burn model and heat-denatured human umbilical vein endothelial cells (HUVECs) model (52 °C for 35 s) were used. Autophagy increased significantly in the dermis and HUVECs in a time-dependent manner after heat denaturation and recovery for 2-5 days. Rapamycin-mediated autophagy enhanced the pro-angiogenic effect, evidenced by increased proliferation and migration of HUVECs, and formation of tube-like structures. Autophagy inhibition by 3-Methyladenine (3-MA) abolished the angiogenesis in heat-denatured HUVECs after recovery for 3-5 days. Moreover, heat denaturation augmented the phosphorylation of AMP-activated protein kinase (AMPK) but reduced the phosphorylation of Akt and mTOR in HUVECs. Furthermore, autophagy inhibition by antioxidant NAC, compound C or AMPK siRNA impaired cell proliferation, migration and tube formation heat-denatured HUVECs. At last, the in vivo experiments also showed that inhibition of autophagy by bafilomycin A1 could suppress angiogenesis and recovery of heat-denatured dermis.Taken together, we firstly revealed that autophagy promotes angiogenesis via AMPK/Akt/mTOR signaling during the recovery of heat-denatured endothelial cells and may provide a potential therapeutic target for the recovery of heat-denatured dermis.

Potential mechanisms for the effects of far-infrared on the cardiovascular system - a review

Far-infrared (FIR) is a form of thermal radiation, which may have beneficial effects on cardiovascular health. Clinical studies suggest that FIR irradiation may have therapeutic effects in heart failure, myocardial ischaemia and may improve flow and survival of arteriovenous fistula. Animal studies have suggested a wide range of potential mechanisms involving endothelial nitric oxide synthase and nitric oxide bioavailability, oxidative stress, heat shock proteins and endothelial precursor cells. However, the exact cellular and molecular mechanism of FIR on the cardiovascular system remains elusive. The purpose of this review is to discuss the current literature, focusing on mechanistic studies involving the cardiovascular system, and with a view to highlighting areas for future investigation.

Effects of Combined Far-Infrared Radiation and Acupuncture at ST36 on Peripheral Blood Perfusion and Autonomic Activities

Using four-channel photoplethysmography (PPG) for acquiring peripheral arterial waveforms, this study investigated vascular and autonomic impacts of combined acupuncture-far infrared radiation (FIR) in improving peripheral circulation. Twenty healthy young adults aged 25.5 ± 4.6 were enrolled for 30-minute measurement. Each subject underwent four treatment strategies, including acupuncture at ST36 (Zusanli), pseudoacupuncture, FIR, and combined acupuncture-FIR at different time points. Response was assessed at 5-minute intervals. Area under arterial waveform at baseline was defined as AreaBaseline, whereas AreaStim referred to area at each 5-minute substage during and after treatment. AreaStim/AreaBaseline was compared at different stages and among different strategies. Autonomic activity at different stages was assessed using low-to-high frequency power ratio (LHR). The results demonstrated increased perfusion for each therapeutic strategy from stage 1 to stage 2 (all p < 0.02). Elevated perfusion was noted for all treatment strategies at stage 3 compared to stage 1 except pseudoacupuncture. Increased LHR was noted only in subjects undergoing pseudoacupuncture at stage 3 compared to stage 1 (p = 0.045). Reduced LHR at stage 2 compared to stage 1 was found only in combined treatment group (p = 0.041). In conclusion, the results support clinical benefits of combined acupuncture-FIR treatment in enhancing peripheral perfusion and parasympathetic activity.

Far-infrared suppresses skin photoaging in ultraviolet B-exposed fibroblasts and hairless mice

Ultraviolet (UV) induces skin photoaging, which is characterized by thickening, wrinkling, pigmentation, and dryness. Collagen, which is one of the main building blocks of human skin, is regulated by collagen synthesis and collagen breakdown. Autophagy was found to block the epidermal hyperproliferative response to UVB and may play a crucial role in preventing skin photoaging. In the present study, we investigated whether far-infrared (FIR) therapy can inhibit skin photoaging via UVB irradiation in NIH 3T3 mouse embryonic fibroblasts and SKH-1 hairless mice. We found that FIR treatment significantly increased procollagen type I through the induction of the TGF-β/Smad axis. Furthermore, UVB significantly enhanced the expression of matrix metalloproteinase-1 (MMP-1) and MMP-9. FIR inhibited UVB-induced MMP-1 and MMP-9. Treatment with FIR reversed UVB-decreased type I collagen. In addition, FIR induced autophagy by inhibiting the Akt/mTOR signaling pathway. In UVB-induced skin photoaging in a hairless mouse model, FIR treatment resulted in decreased skin thickness in UVB irradiated mice and inhibited the degradation of collagen fibers. Moreover, FIR can increase procollagen type I via the inhibition of MMP-9 and induction of TGF-β in skin tissues. Therefore, our study provides evidence for the beneficial effects of FIR exposure in a model of skin photoaging.

Far-infrared protects vascular endothelial cells from advanced glycation end products-induced injury via PLZF-mediated autophagy in diabetic mice

The accumulation of advanced glycation end products (AGEs) in diabetic patients induces vascular endothelial injury. Promyelocytic leukemia zinc finger protein (PLZF) is a transcription factor that can be activated by low-temperature far-infrared (FIR) irradiation to exert beneficial effects on the vascular endothelium. In the present study, we investigated the influence of FIR-induced PLZF activation on AGE-induced endothelial injury both in vitro and in vivo. FIR irradiation inhibited AGE-induced apoptosis in human umbilical vein endothelial cells (HUVECs). PLZF activation increased the expression of phosphatidylinositol-3 kinases (PI3K), which are important kinases in the autophagic signaling pathway. FIR-induced PLZF activation led to autophagy in HUVEC, which was mediated through the upregulation of PI3K. Immunofluorescence staining showed that AGEs were engulfed by HUVECs and localized to lysosomes. FIR-induced autophagy promoted AGEs degradation in HUVECs. In nicotinamide/streptozotocin-induced diabetic mice, FIR therapy reduced serum AGEs and AGEs deposition at the vascular endothelium. FIR therapy also reduced diabetes-induced inflammatory markers in the vascular endothelium and improved vascular endothelial function. These protective effects of FIR therapy were not found in PLZF-knockout mice. Our data suggest that FIR-induced PLZF activation in vascular endothelial cells protects the vascular endothelium in diabetic mice from AGE-induced injury.

Effects of far infrared rays emitting clothing on recovery after an intense plyometric exercise bout applied to elite soccer players: a randomized double-blind placebo-controlled trial

The aim was to investigate the effects of far infrared (FIR) ray emitting clothes on indirect markers of exercise-induced muscle damage and physical performance recovery after a plyometric bout applied to soccer players. Twenty-one male players (18.9±0.6 years; 70.8±5.01 kg; 178.3±0.06 cm) performed 100 drop-jumps. Six hours after the bout, athletes put on FIR clothes (FIR) (density of 225 g·m^-2, 88% far infrared rays emitting polyamide 66 Emana yarn (PA66) fibre, 12% Spandex, emissivity of 0.88 and power emitted of 341 W/m2µm at 37°C in the 5-20 µm wavelength range, patent WO 2009/077834 A2) (N = 10) or placebo clothes (PLA) (N = 11). Mid-thigh circumferences, creatine kinase (CK), and delayed-onset muscle soreness (DOMS) were assessed before, immediately after and 24, 48, and 72 h after the bout. Squat (SJ) and countermovement jump (CMJ) heights were measured before and at 24, 48, and 72 h after, while 1RM leg press (maximum strength) was measured before and at 72 h after the plyometrics. No differences between groups were found in mid-thigh circumferences, SJ, CMJ or 1RM. CK increased significantly 24 h after the plyometrics in comparison to before (p < 0.05) in both groups. PLA showed significant DOMS increases at 24, 48, and 72 h, while FIR showed significant increases at 24 and 48 h (p < 0.05). DOMS effect sizes were greater in FIR (moderate at 48 h, ES = 0.737 and large at 72 h, ES = 0.844), suggesting that FIR clothes may reduce perceived DOMS after an intense plyometric session performed by soccer players.

Far-infrared promotes burn wound healing by suppressing NLRP3 inflammasome caused by enhanced autophagy

Understanding the underlying molecular mechanisms in burn wound progression is crucial to providing appropriate diagnoses and designing therapeutic regimens for burn patients. When inflammation becomes unregulated, recurrent, or excessive, it interferes with burn wound healing. Autophagy, which is a homeostatic and catabolic degradation process, was found to protect against ischemic injury, inflammatory diseases, and apoptosis in some cases. In the present study, we investigated whether far-infrared (FIR) could ameliorate burn wound progression and promote wound healing both in vitro and in a rat model of deep second-degree burn. We found that FIR induced autophagy in differentiated THP-1 cells (human monocytic cells differentiated to macrophages). Furthermore, FIR inhibited both the NLRP3 inflammasome and the production of IL-1β in lipopolysaccharide-activated THP-1 macrophages. In addition, FIR induced the ubiquitination of ASC, which is the adaptor protein of the inflammasome, by increasing tumor necrosis factor receptor-associated factor 6 (TRAF6), which is a ubiquitin E3 ligase. Furthermore, the exposure to FIR then promoted the delivery of inflammasome to autophagosomes for degradation. In a rat burn model, FIR ameliorated burn-induced epidermal thickening, inflammatory cell infiltration, and loss of distinct collagen fibers. Moreover, FIR enhanced autophagy and suppressed the activity of the NLRP3 inflammasome in the rat skin tissue of the burn model. Based on these results, we suggest that FIR-regulated autophagy and inflammasomes will be important for the discovery of novel therapeutics to promote the healing of burn wounds.

KEY MESSAGES

Far-infrared (FIR) induced autophagy in THP-1 macrophages. FIR suppressed the NLRP3 inflammasome through the activation of autophagy. FIR induced the ubiquitination of ASC by increasing TRAF6. FIR ameliorated burn wound progression and promoted wound healing in a rat burn model.

Long-term antihypertensive effects of far-infrared ray irradiated from wooden board in spontaneously hypertensive rats

Background

Far-infrared ray (FIR) has been widely used in promoting health and has been shown to exert beneficial effects in vascular function. The non-thermal effect of FIR has been found to play a significant role in the protective effect on some vascular-related diseases, but its protective effects and use against hypertension have not been clearly presented.

Methods

In the present study, by using a wooden board coated with FIR-irradiated materials, we evaluated the long-term antihypertensive effect on spontaneously hypertensive rats (SHRs) in the environment in contact with the FIR-irradiated wooden board. SHRs were placed on the wooden board with or without FIR radiation for 4 weeks.

Results

The systolic blood pressure (BP) of SHRs undergoing different treatments was measured weekly using a tail-cuff method. FIR radiation significantly reduced the systolic BP of the SHRs along with a decreasing plasma level of angiotensin II and an increasing plasma level of bradykinin. In addition, long-term contact of FIR did not significantly affect the BP in normotensive Wistar Kyoto rats (WKYs).

Conclusions

Our results provided the evidence based on which FIR radiation could be considered an effective non-pharmacological choice for preventing hypertension.

Peroxisome Proliferator-Activated Receptor α Protects Renal Tubular Cells from Gentamicin-Induced Apoptosis via Upregulating Na+/H+ Exchanger NHE1

Peroxisome proliferator-activated receptor (PPAR)-α is a transcription factor that has been reported to inhibit gentamicin-induced apoptosis in renal tubular cells. However, the antiapoptotic mechanism of PPARα is still unknown. In this study, we found that PPARα overexpression induced Na⁺/H⁺ exchanger-1 (NHE1) expression in the rat renal tubular cells NRK-52E. Beraprost, a PPARα ligand, also increased NHE1 expression in the renal tubules in normal mice, but not in PPARα knockout mice. Chromatin immunoprecipitation assays revealed that two PPARα binding elements were located in the rat NHE1 promoter region. Na⁺/H⁺ exchanger activity also increased in the PPARα-overexpressed cells. Flow cytometry showed that the PPARα-overexpressed cells were resistant to apoptosis-induced shrinkage. Cariporide, a selective NHE1 inhibitor, inhibited the antiapoptotic effect of PPARα in the gentamicin-treated cells. The interaction between NHE1 and ezrin/radixin/moesin (ERM) and between ERM and phosphatidylinositol 4,5-bisphosphate in the PPARα-overexpressed cells was more than in the control cells. ERM short interfering RNA (siRNA) transfection inhibited the PPARα-induced antiapoptotic effect. PPARα overexpression also increased the phosphoinositide 3-kinase (PI3K) expression, which is dependent on NHE1 activity. Increased PI3K further increased the phosphorylation of the prosurvival kinase Akt in the PPARα-overexpressed cells. Wortmannin, a PI3K inhibitor, inhibited PPARα-induced Akt activity and the antiapoptotic effect. We conclude that PPARα induces NHE1 expression and then recruits ERM to promote PI3K/Akt-mediated cell survival in renal tubular cells. The application of PPARα activation reduces the nephrotoxicity of gentamicin and may expand the clinical use of gentamicin.

A Parallel-Arm Randomized Controlled Trial to Assess the Effects of a Far-Infrared-Emitting Collar on Neck Disorder

The purpose of this study is to assess the beneficial effects of a far-infrared-emitting collar (FIRC) on the management of neck disorders. A neck disorder is generalized as neck muscle pain and its relative mental disorders because the etiologies of the neck's multidimensional syndrome are either muscle impairment or psychiatric distress. This is the first study to determine the efficacy of a FIRC by evaluating objective physical evidence and psychometric self-reports using a parallel-arm randomized sham-controlled and single-blinded design. In this trial, 60 participants with neck disorders were observed at baseline and post-intervention. Compared to the placebo group after a 30-min intervention, the FIRC demonstrated a statistically significant biological effect in elevating skin temperature and promoting blood circulation with p-values 0.003 and 0.020, respectively. In addition, FIRC application significantly reduced neck muscle tension, relieved pain, ameliorated fatigue, improved depression, and decreased anxiety. The FIRC could therefore be a potential treatment for neck disorders.

Lycopene inhibits cyclic strain-induced endothelin-1 expression through the suppression of reactive oxygen species generation and induction of heme oxygenase-1 in human umbilical vein endothelial cells

Lycopene is the most potent active antioxidant among the major carotenoids, and its use has been associated with a reduced risk for cardiovascular disease (CVD). Endothelin-1 (ET-1) is a powerful vasopressor synthesized by endothelial cells and plays a crucial role in the pathophysiology of CVD. However, the direct effects of lycopene on vascular endothelial cells have not been fully described. This study investigated the effects of lycopene on cyclic strain-induced ET-1 gene expression in human umbilical vein endothelial cells (HUVECs) and identified the signal transduction pathways that are involved in this process. Cultured HUVECs were exposed to cyclic strain (20% in length, 1 Hz) in the presence or absence of lycopene. Lycopene inhibited strain-induced ET-1 expression through the suppression of reactive oxygen species (ROS) generation through attenuation of p22(phox) mRNA expression and NAD(P)H oxidase activity. Furthermore, lycopene inhibited strain-induced ET-1 secretion by reducing ROS-mediated extrace-llular signal-regulated kinase (ERK) phosphorylation. Conversely, lycopene treatment enhanced heme oxygenase-1 (HO-1) gene expression through the activation of phosphoinositide 3-kinase (PI3K)/Akt pathway, followed by induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation; in addition, HO-1 silencing partially inhibited the repressive effects of lycopene on strain-induced ET-1 expression. In summary, our study showed, for the first time, that lycopene inhibits cyclic strain-induced ET-1 gene expression through the suppression of ROS generation and induction of HO-1 in HUVECs. Therefore, this study provides new valuable insight into the molecular pathways that may contribute to the proposed beneficial effects of lycopene on the cardiovascular system.

Far-infrared therapy for cardiovascular, autoimmune, and other chronic health problems: A systematic review

Physical therapy (physiotherapy), a complementary and alternative medicine therapy, has been widely applied in diagnosing and treating various diseases and defects. Increasing evidence suggests that convenient and non-invasive far-infrared (FIR) rays, a vital type of physiotherapy, improve the health of patients with cardiovascular disease, diabetes mellitus, and chronic kidney disease. Nevertheless, the molecular mechanisms by which FIR functions remain elusive. Hence, the purpose of this study was to review and summarize the results of previous investigations and to elaborate on the molecular mechanisms of FIR therapy in various types of disease. In conclusion, FIR therapy may be closely related to the increased expression of endothelial nitric oxide synthase as well as nitric oxide production and may modulate the profiles of some circulating miRNAs; thus, it may be a beneficial complement to treatments for some chronic diseases that yields no adverse effects.

Effects of far-infrared radiation on heart rate variability and central manifestations in healthy subjects: a resting-fMRI study

The aim of this study was to investigate the autonomic responses and central manifestations by peripheral FIR stimulation. Ten subjects (mean ± SD age 26.2 ± 3.52 years) received FIR stimulation at left median nerve territory for 40 min. Electrocardiograph was continuously recorded and heart rate variability (HRV) were analyzed. By using a 3 T-MRI scanner, three sessions of resting-state functional magnetic resonance images (fMRI) were acquired, namely, before (baseline-FIR), immediately after (IA-FIR) and 15 min after FIR was turned off (Post-FIR). The fractional amplitude of low-frequency (0.01-0.08 Hz) fluctuation (fALFF) of each session to evaluate the intensity of resting-brain activity in each session was analyzed. Our results showed that FIR stimulation induced significant HRV responses such as an increasing trend of nLF and LF/HF ratio, while FIR increased fALFF in right superior front gyrus, middle frontal gyrus and decreased the resting brain activity at fusiform gyrus, extrastriae cortex, inferior temporal gyrus and middle temporal gyrus, especially 15 min after FIR was turned off. We conclude that the central manifestation and the autonomic responses are prominent during and after FIR stimulation, which provide important mechanistic explanation on human disorder treated by such energy medicine.

Lycopene Inhibits Urotensin-II-Induced Cardiomyocyte Hypertrophy in Neonatal Rat Cardiomyocytes

This study investigated how lycopene affected urotensin-II- (U-II-) induced cardiomyocyte hypertrophy and the possible implicated mechanisms. Neonatal rat cardiomyocytes were exposed to U-II (1 nM) either exclusively or following 6 h of lycopene pretreatment (1-10  μ M). The lycopene (3-10  μ M) pretreatment significantly inhibited the U-II-induced cardiomyocyte hypertrophy, decreased the production of U-II-induced reactive oxygen species (ROS), and reduced the level of NAD(P)H oxidase-4 expression. Lycopene further inhibited the U-II-induced phosphorylation of the redox-sensitive extracellular signal-regulated kinases. Moreover, lycopene treatment prevented the increase in the phosphorylation of serine-threonine kinase Akt and glycogen synthase kinase-3beta (GSK-3 β ) caused by U-II without affecting the protein levels of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN). However, lycopene increased the PTEN activity level, suggesting that lycopene prevents ROS-induced PTEN inactivation. These findings imply that lycopene yields antihypertrophic effects that can prevent the activation of the Akt/GSK-3 β hypertrophic pathway by modulating PTEN inactivation through U-II treatment. Thus, the data indicate that lycopene prevented U-II-induced cardiomyocyte hypertrophy through a mechanism involving the inhibition of redox signaling. These findings provide novel data regarding the molecular mechanisms by which lycopene regulates cardiomyocyte hypertrophy.

Docosahexaenoic acid inhibits vascular endothelial growth factor (VEGF)-induced cell migration via the GPR120/PP2A/ERK1/2/eNOS signaling pathway in human umbilical vein endothelial cells

Cell migration plays an important role in angiogenesis and wound repair. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that is essential for endothelial cell survival, proliferation, and migration. Docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, shows both anti-inflammatory and antioxidant activities in vitro and in vivo. This study investigated the molecular mechanism by which DHA down-regulates VEGF-induced cell migration. HUVECs were used as the study model, and the MTT assay, Western blot, wound-healing assay, and phosphatase activity assay were used to explore the effects of DHA on cell migration. GPR120 is the putative receptor for DHA action. The results showed that DHA, PD98059 (an ERK1/2 inhibitor), and GW9508 (a GPR120 agonist) inhibited VEGF-induced cell migration. In contrast, pretreatment with okadaic acid (OA, a PP2A inhibitor) and S-nitroso-N-acetyl-DL-penicillamine (an NO donor) reversed the inhibition of cell migration by DHA. VEGF-induced cell migration was accompanied by phosphorylation of ERK1/2 and eNOS. Treatment of HUVECs with DHA increased PP2A enzyme activity and decreased VEGF-induced phosphorylation of ERK1/2 and eNOS. However, pretreatment with OA significantly decreased DHA-induced PP2A enzyme activity and reversed the DHA inhibition of VEGF-induced ERK1/2 and eNOS phosphorylation. These results suggest that stimulation of PP2A activity and inhibition of the VEGF-induced ERK1/2/eNOS signaling pathway may be involved in the DHA suppression of VEGF-induced cell migration. Thus, the effect of DHA on angiogenesis and wound repair is at least partly by virtue of its attenuation of cell migration.

Urotensin II induces interleukin 8 expression in human umbilical vein endothelial cells

BACKGROUND

Urotensin II (U-II), an 11-amino acid peptide, exerts a wide range of actions in cardiovascular systems. Interleukin-8 (IL-8) is secreted by endothelial cells, thereby enhancing endothelial cell survival, proliferation, and angiogenesis. However, the interrelationship between U-II and IL-8 as well as the detailed intracellular mechanism of U-II in vascular endothelial cells remain unclear. The aim of this study was to investigate the effect of U-II on IL-8 expression and to explore its intracellular mechanism in human umbilical vein endothelial cells.

METHODS/PRINCIPAL FINDINGS

Primary human umbilical vein endothelial cells were used. Expression of IL-8 was determined by real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and luciferase reporter assay. Western blot analyses and experiments with specific inhibitors were performed to reveal the downstream signaling pathways as concerned. U-II increased the mRNA/protein levels of IL-8 in human umbilical vein endothelial cells. The U-II effects were significantly inhibited by its receptor antagonist [Orn(5)]-URP. Western blot analyses and experiments with specific inhibitors indicated the involvement of phosphorylation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinase in U-II-induced IL-8 expression. Luciferase reporter assay further revealed that U-II induces the transcriptional activity of IL-8. The site-directed mutagenesis indicated that the mutation of AP-1 and NF-kB binding sites reduced U-II-increased IL-8 promoter activities. Proliferation of human umbilical vein endothelial cells induced by U-II could be inhibited significantly by IL-8 RNA interference.

CONCLUSION/SIGNIFICANCE

The results show that U-II induces IL-8 expression in human umbilical vein endothelial cells via p38 mitogen-activated protein kinase and extracellular signal-regulated kinase signaling pathways and IL-8 is involved in the U-II-induced proliferation of human umbilical vein endothelial cells.

Clinical Application of Endothelial Progenitor Cell: Are We Ready?

The discovery of circulating endothelial progenitor cells (EPCs) opened up a new era of EPC-based therapies for cardiovascular diseases. While researchers are enthusiastic about applying EPCs to clinical therapy, progress has been substantially limited due to the lack of a thorough characterization and understanding of early and late outgrowth EPCs (also called endothelial colony-forming cell, ECFCs) biology. As a means of facilitating the understanding of how late EPCs can most effectively be applied to clinical therapeutics, this article reviews the recent progress covering 5 important issues: (1) The best passages of ex vivo-cultivated EPCs for cell therapy; (2) inflammatory activation of late EPCs: a real world consideration; (3) late EPC is not an endothelial cell: an issue of cell contamination; (4) ways to improve EPC function and differentiation; and (5) how to separate and delete smooth muscle progenitor cells (SPCs).

KEY WORDS

Cardiovascular disease; Cell therapy; Endothelial progenitor cell; Smooth muscle progenitor cell.

The expression and proangiogenic effect of nucleolin during the recovery of heat-denatured HUVECs

BACKGROUND

The present study aims to examine the expression patterns and roles of nucleolin during the recovery of heat-denatured human umbilical vein endothelial cells (HUVECs).

METHODS

Deep partial thickness burn model in Sprague-Dawley rats and the heat denatured cell model (52°C, 35s) were used. The expression of nucleolin was measured using Western blot analysis and real-time PCR. Angiogenesis was assessed using in vitro parameters including endothelial cell proliferation, transwell migration assay, and scratched wound healing. Gene transfection and RNA interference approaches were employed to investigate the roles of nucleolin.

RESULTS

Nucleolin mRNA and protein expression showed a time-dependent increase during the recovery of heat-denatured dermis and HUVECs. Heat-denaturation time-dependently promoted cell growth, adhesion, migration, scratched wound healing and formation of tube-like structures in HUVECs. These effects of heat denaturation on endothelial wound healing and formation of tube-like structures were prevented by knockdown of nucleolin, whereas over-expression of nucleolin increased cell growth, migration, and formation of tube-like structures in cultured HUVEC endothelial cells. In addition, we found that the expression of vascular endothelial growth factor (VEGF) increased during the recovery of heat-denatured dermis and HUVECs, and nucleolin up-regulated VEGF in HUVECs.

CONCLUSIONS

The present study reveals that the expression of nucleolin is up-regulated, and plays a pro-angiogenic role during the recovery of heat-denatured dermis and its mechanism is probably dependent on production of VEGF.

GENERAL SIGNIFICANCE

We find a novel and important pro-angiogenic role of nucleolin during the recovery of heat-denatured dermis.

Effects of somatothermal far-infrared ray on primary dysmenorrhea: a pilot study

The purpose of this study was to assess the beneficial effects of using a far-infrared (FIR) belt on the management of patients with primary dysmenorrhea. This is the first study to determine the efficacy of somatothermal FIR using a parallel-arm randomized sham-controlled and double-blinded design with objective physical evidence and psychometric self-reports. Fifty-one Taiwanese women with primary dysmenorrhea were enrolled in the study. Results indicate that there was an increased abdominal temperature of 0.6°C and a 3.27% increase in abdominal blood flow in the FIR group (wearing FIR belt) compared to those in the control group (wearing sham belt). Verbal rating scale and numeric rating scale scores in the FIR group were both lower than those in the control group. Compared to the blank group (wearing no belt), the average dysmenorrhea pain duration of the FIR group was significantly reduced from 2.5 to 1.8 days, but there was no significant difference in the control group. These results demonstrate that the use of a belt made of far-infrared ceramic materials can reduce primary dysmenorrhea.