Syringaresinol Reverses Age-Related Skin Atrophy by Suppressing FoxO3a-Mediated Matrix Metalloproteinase-2 Activation in Copper/Zinc Superoxide Dismutase-Deficient Mice

Adiponectin inhibits ROS/NLRP3 inflammatory pathway through FOXO3A to ameliorate oral submucosal fibrosis

Oral submucous fibrosis (OSF) is an oral condition characterized by chronic progression, which may lead to the development of malignancy. Currently, available treatments for OSF only provide temporary relief of symptoms, and there is a limited availability of effective interventions that can effectively cure this condition. In this study, we aimed to investigate whether adiponectin (APN) could ameliorate OSF and the mechanisms involved in it. First, human oral mucosal fibroblasts (HOMFs) were cultured, an OSF model was established using arecoline, and APN and Imiquimod treatment were administered. Then we overexpressed NLRP3 and knocked down FOXO3A. FOXO3A, fibrosis-related factors (ɑ-SMA, COL1A, CTGF), TGF-β1/Smad3 signaling-related factors (TGF-β1, p-Smad3, Smad3), NLRP3 inflammasome-related factors (NLRP3, Caspase-1, IL-1β), and ROS levels were evaluated. Finally, we explored the effect of APN on OSF in mice by in vivo experiments. We found that arecoline significantly increased ɑ-SMA, COL1A, CTGF, and TGF-β1 expressions and promoted Smad3 phosphorylation, while APN significantly inhibited the elevation of these fibrosis-related factors. ROS production was significantly elevated in HOMFs after arecoline treatment, while APN treatment inhibited ROS production. However, the addition of Imiquimod and overexpression of NLRP3 exhibited a trend of elevated ROS, resisting the inhibitory effect of APN. Furthermore, adding Imiquimod and overexpression of NLRP3 elevated ɑ-SMA, COL1A and CTGF and activated TGF-β1/Smad3 signaling pathway. Additionally, knockdown of FOXO3A enhanced APN-inhibited ɑ-SMA and COL1A. In vivo experiments further confirmed that APN ameliorated OSF in mice by inhibiting ROS/NLRP3 inflammatory pathway. In conclusion, APN ameliorated arecoline-induced OSF by promoting FOXO3A expression and downregulating the ROS/NLRP3 pathway.

The Antioxidant PAPLAL Protects against Allergic Contact Dermatitis in Experimental Models

PAPLAL, a mixture of platinum (nPt) and palladium (nPd) nanoparticles, is widely used as a topical agent because of its strong antioxidant activity. Allergic contact dermatitis (ACD) is one of the most common occupational skin diseases worldwide. However, the role of oxidative stress in ACD remains unclear. In the present study, we investigated the protective effects of topical PAPLAL treatment on 2,4-dinitrofluorobenzene (DNFB)-induced ACD. DNFB treatment increased 8-isoprostane content; upregulated Xdh, Nox2, and Nox4, pro-oxidant genes; and downregulated Sod1, an antioxidant gene, indicating oxidative damage in the ear skin. PAPLAL therapy significantly reduced ear thickness associated with the downregulation of inflammatory cytokine-related genes. PAPLAL also significantly increased the expression of the stress-response-related genes Ahr and Nrf2, as well as their target genes, but failed to alter the expression of redox-related genes. Furthermore, Sod1 loss worsened ACD pathologies in the ear. These results strongly suggest that PAPLAL protects against ACD through its antioxidant activity and activation of the AHR and NRF2 axes. The antioxidant PAPLAL can be used as a novel topical therapy for ACD that targets oxidative stress.

(-)-Syringaresinol attenuates ulcerative colitis by improving intestinal epithelial barrier function and inhibiting inflammatory responses

BACKGROUND

(-)-Syringaresinol (SYR), a natural lignan with significant antioxidant and anti-inflammatory activities, possesses various pharmacological benefits including cardio-protective, antibacterial, anticancer, and anti-aging effects. It was shown that the effectiveness of (+)-syringaresinol diglucoside on the ulcerative colitis (UC) was attributed to the active metabolite (+)-syringaresinol (the enantiomor of SYR). However, the efficacy of SYR against UC remains unclear, and the associated molecular mechanism has not been revealed yet PURPOSE: This study aimed to assess the protective effect of SYR in UC and its underlying mechanism STUDY DESIGN AND METHODS: We examined SYR's protective impact on the intestinal epithelial barrier and its ability to inhibit inflammatory responses in both a lipopolysaccharide (LPS)-induced Caco-2 cell model and a dextran sodium sulfate (DSS)-induced UC mouse model. We also explored the potential signaling pathways regulated by SYR using transcriptome analysis and western blot assay RESULTS: In Caco-2 cells, SYR significantly increased trans-epithelial electrical resistance, reduced tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interferon-γ (IFN-γ), and cyclooxygenase-2 (COX-2) levels, and enhanced cellular tight junction protein expression and distribution. In mice with UC, oral treatment with SYR (10, 20, 40 mg·kg-1) dose-dependently increased body weight, colon length, and expression of tight junction proteins, decreased disease activity index score, spleen coefficient, cytokine serum levels, bacterial translocation, and intestinal damage, and also preserved the ultrastructure of colonic mucosal cells. Transcriptomics indicated that the anti-UC effect of SYR is mediated via the PI3K-Akt/MAPK/Wnt signaling pathway.

CONCLUSION

In summary, SYR effectively mitigated the development of UC by enhancing the intestinal epithelial barrier function and attenuating the inflammatory response. The plant-derived product SYR might be a potentially effective therapeutical agent against UC.

Skin wound healing effects of (+)-syringaresinol from ginseng berry

Background

Ginseng has been used as a traditional medicine and functional cosmetic ingredients for many years. Recent studies have focused on the potential biological effects of the ginseng berry and its ingredients. (+)-Syringaresinol (SYR) is enriched in ginseng berry and its beneficial effects on the skin have been recently reported. However, little is known about the its effects on the wound healing process of skin.

Methods

Here, we evaluated the skin wound healing effect of (+)-SYR using the human fibroblast Hs68 cell and ex vivo pig and human skin tissue model. Scratch wound test and hydrogen peroxide (HPO) induce chemical wound model were employed.

Results

(+)-SYR promoted the migration and proliferation of Hs68 cells without significant cytotoxicity at the tested concentrations. Especially, in ex vivo pig and human skin tissue, HPO-induced chemical wound was recovered almost completely by (+)-SYR. In line with the finding in Hs68, the protein expression levels of TGF-β and PCNA, a proliferation marker were increased, demonstrating the beneficial effects of (+)-SYR on skin wound repair.

Conclusion

Collectively, we demonstrated that (+)-SYR from ginseng berry, can enhance the wound healing effect by accelerating cell proliferation and skin regeneration, suggesting the potential utility of (+)-SYR for skin wound repair.

Low back pain and osteoarthritis pain: a perspective of estrogen

Low back pain (LBP) is the world's leading cause of disability and is increasing in prevalence more rapidly than any other pain condition. Intervertebral disc (IVD) degeneration and facet joint osteoarthritis (FJOA) are two common causes of LBP, and both occur more frequently in elderly women than in other populations. Moreover, osteoarthritis (OA) and OA pain, regardless of the joint, are experienced by up to twice as many women as men, and this difference is amplified during menopause. Changes in estrogen may be an important contributor to these pain states. Receptors for estrogen have been found within IVD tissue and nearby joints, highlighting the potential roles of estrogen within and surrounding the IVDs and joints. In addition, estrogen supplementation has been shown to be effective at ameliorating IVD degeneration and OA progression, indicating its potential use as a therapeutic agent for people with LBP and OA pain. This review comprehensively examines the relationship between estrogen and these pain conditions by summarizing recent preclinical and clinical findings. The potential molecular mechanisms by which estrogen may relieve LBP associated with IVD degeneration and FJOA and OA pain are discussed.

Syringaresinol protects against diabetic nephropathy by inhibiting pyroptosis via NRF2-mediated antioxidant pathway

Diabetic nephropathy (DN) is one of the serious complications of diabetes that has limited treatment options. As a lytic inflammatory cell death, pyroptosis plays an important role in the pathogenesis of DN. Syringaresinol (SYR) possesses anti-inflammatory and antioxidant properties. However, the therapeutic effects and the underlying mechanism of SYR in DN remain unclear. Herein, we showed that SYR treatment ameliorated renal hypertrophy, fibrosis, mesangial expansion, glomerular basement membrane thickening, and podocyte foot process effacement in streptozotocin (STZ)-induced diabetic mice. Mechanistically, SYR prevented the abundance of pyroptosis-related proteins such as NOD-like receptor family pyrin domain containing 3 (NLRP3), cysteinyl aspartate-specific proteinase 1 (Caspase-1), and gasdermin D (GSDMD), and the biosynthesis of inflammatory cytokines interleukin 1β (IL-1β) and interleukin 18 (IL-18). In addition, SYR promoted the nuclear translocation of nuclear factor E2-related factor 2 (NRF2) and enhanced the downstream antioxidant enzymes heme oxygenase 1 (HO-1) and manganese superoxide dismutase (MnSOD), thereby effectively decreasing excess reactive oxygen species (ROS). Most importantly, knockout of NRF2 abolished SYR-mediated renoprotection and anti-pyroptotic activities in NRF2-KO diabetic mice. Collectively, SYR inhibited the NLRP3/Caspase-1/GSDMD pyroptosis pathway by upregulating NRF2 signaling in DN. These findings suggested that SYR may be promising a therapeutic option for DN.

Lignans as Pharmacological Agents in Disorders Related to Oxidative Stress and Inflammation: Chemical Synthesis Approaches and Biological Activities

Plant lignans exhibit a wide range of biological activities, which makes them the research objects of potential use as therapeutic agents. They provide diverse naturally-occurring pharmacophores and are available for production by chemical synthesis. A large amount of accumulated data indicates that lignans of different structural groups are apt to demonstrate both anti-inflammatory and antioxidant effects, in many cases, simultaneously. In this review, we summarize the comprehensive knowledge about lignan use as a bioactive agent in disorders associated with oxidative stress and inflammation, pharmacological effects in vitro and in vivo, molecular mechanisms underlying these effects, and chemical synthesis approaches. This article provides an up-to-date overview of the current data in this area, available in PubMed, Scopus, and Web of Science databases, screened from 2000 to 2022.

Syringaresinol attenuates sepsis-induced cardiac dysfunction by inhibiting inflammation and pyroptosis in mice

The mortality of sepsis-induced cardiac dysfunction (SICD) is very high due to the complex pathophysiological mechanism. Syringaresinol (SYR) is a natural abstract which possesses anti-inflammatory property. The present study aims was to identify the protective impact of SYR on sepsis-induced cardiac dysfunction and investigate the specific mechanisms. We found that SYR improved the cardiac function and alleviated myocardial injury in mice that subjected to cecal ligation and puncture, in addition, SIRT1 expression was significantly elevated after SYR treatment compared to sepsis group both in vivo and in vitro, along with suppression of NLRP3 activation and proinflammatory cytokines release. However, SIRT1 inhibitor EX427 abolished the impact of SYR on LPS-induced pyroptosis in cardiomyocytes. Furthermore, molecular docking analysis predicted that there is high affinity between SYR and estrogen receptor (ER), ER inhibitor ICI182780, the specific ERβ inhibitor PHTP and the specific ERαinhibitor AZD9496 were used to examine the role of ER in the protective effect of SYR against SICD, and the results suggested that ER activation was essential for the cardioprotective function of SYR. In conclusion, SYR ameliorates SICD via the ER/SIRT1/NLRP3/GSDMD pathway.

Syringaresinol Resisted Sepsis-Induced Acute Lung Injury by Suppressing Pyroptosis Via the Oestrogen Receptor-β Signalling Pathway

Acute lung injury (ALI) is a common lung disease characterized by severe acute inflammatory lung injury in patients with sepsis. Syringaresinol (SYR) has been reported to have anti-apoptotic and anti-inflammatory effects, but whether it could prevent pyroptosis to improve sepsis-induced ALI remains unclear. The purpose of this work was to examine the impact of SYR on sepsis-induced ALI and investigate the underlying mechanisms. The ALI model was induced by caecal ligation and puncture (CLP) in C57BL/6 mice, structural damage in the lung tissues was determined using haematoxylin and eosin (HE) staining, and the levels of related inflammatory cytokines and macrophage polarization were examined by enzyme-linked immunosorbent assays (ELISAs) and flow cytometry, respectively. The activation of the NLRP3 inflammasome and the protein levels of TLR4, NF-κB and MAPKs was measured by western blotting. The results demonstrated that SYR pretreatment significantly reduced lung tissue histological damage, inhibited the production of proinflammatory cytokines and albumin in bronchoalveolar lavage fluid (BALF), and decreased myeloperoxidase (MPO) levels, thereby alleviating lung tissue injury. Meanwhile, septic mice treated with SYR displayed a higher survival rate and lower percentage of M1 macrophages in the BALF and spleen than septic mice. In addition, lung tissues from the CLP + SYR group exhibited downregulated protein expression of NLRP3, ASC, GSDMD caspase-1 p20 and TLR4, along with decreased phosphorylated levels of NF-κB, ERK, JNK and P38, indicating that SYR administration effectively prevented CLP-induced pyroptosis in the lung. SYR also suppressed LPS-induced pyroptosis in RAW 264.7 cells by inhibiting the activation of the NLRP3 inflammasome, which was abolished by an oestrogen receptor-β (ERβ) antagonist (PHTPP). In conclusion, SYR exerted protective effects on CLP-induced ALI via the oestrogen receptor-β signalling pathway.

Nutrition and youthful skin

Nutrition and dietary supplements have been used to promote a youthful appearance for millennia. Despite high public demand for these products, evidence supporting their efficacy is limited and often inconsistent. We discuss the structural and functional changes that occur in the skin during the aging process. We also review evidence supporting the use of nutritional supplements commonly used to promote a youthful appearance, including essential fatty acids, coenzyme Q, collagen peptides, curcumin, polyphenols, flavonoids, probiotics, silymarin, and vitamins A, C, D, and E. We also consider the role of advanced glycosylated end products, antiinflammatory diets, and caloric restriction in delaying premature skin aging. Although evidence supporting the use of some dietary interventions is promising, further long-term studies in humans are required to fully understand their effects on the promotion of a youthful appearance.

Bibliometric analysis of the effects of ginseng on skin

OBJECTIVE

Ginseng is widely used in cosmetics and skin care. The progress of research on the effect of ginseng on the skin was explored through a summary and analysis of skin-related studies on ginseng conducted over in the past 20 years, and this exploration aimed to elucidate new research opportunities with regard to the development and application of ginseng treatments for the skin.

MATERIALS AND METHODS

Keywords were used to retrieve human studies related to the use of ginseng to treat skin conditions from the Web of Science. Scientometric analyses were performed in R to analyze the studies on the human skin-related effects of ginseng conducted from 2000 to 2019.

RESULTS

The main active ingredient in ginseng is ginsenoside, and its effects on the skin are mostly anti-aging and whitening. Ginseng extract regulates the levels of matrix metalloproteinases in human fibroblast type I collagen to improve the elasticity and water content of skin. In addition, ginseng inhibits the transcription factors or signaling pathways involved in the formation of melanin, it exerts a whitening effect. The authors of the retrieved studies are mostly located in Asia, mainly South Korea and China. Wang Y, Kim JH, and Kim YJ are relatively influential scholars, these ginseng-related articles published in the Journal of Ginseng Research, Molecules and other journals are very important in this field.

CONCLUSION

This study shows the development of trends in research on ginseng as a raw cosmetic material used on the skin and thus enables researchers to rapidly understand the key information in the field of ginseng research, comprehend the research directions, and improve their research efficiency.

Syringaresinol derived from Panax ginseng berry attenuates oxidative stress-induced skin aging via autophagy

Background

In aged skin, reactive oxygen species (ROS) induces degradation of the extracellular matrix (ECM), leading to visible aging signs. Collagens in the ECM are cleaved by matrix metalloproteinases (MMPs). Syringaresinol (SYR), isolated from Panax ginseng berry, has various physiological activities, including anti-inflammatory action. However, the anti-aging effects of SYR via antioxidant and autophagy regulation have not been elucidated.

Methods

The preventive effect of SYR on skin aging was investigated in human HaCaT keratinocytes in the presence of H₂O₂, and the keratinocyte cells were treated with SYR (0–200 μg/mL). mRNA and protein levels of MMP-2 and -9 were determined by real-time PCR and Western blotting, respectively. Radical scavenging activity was researched by 2,2 diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. LC3B level was assessed by Western blotting and confocal microscopy.

Results

SYR significantly reduced gene expression and protein levels of MMP-9 and -2 in both H₂O₂-treated and untreated HaCaT cells. SYR did not show cytotoxicity to HaCaT cells. SYR exhibited DPPH and ABTS radical scavenging activities with an EC₅₀ value of 10.77 and 10.35 μg/mL, respectively. SYR elevated total levels of endogenous and exogenous LC3B in H₂O₂-stimulated HaCaT cells. 3-Methyladenine (3-MA), an autophagy inhibitor, counteracted the inhibitory effect of SYR on MMP-2 expression.

Conclusion

SYR showed antioxidant activity and up-regulated autophagy activity in H₂O₂-stimulated HaCaT cells, lowering the expression of MMP-2 and MMP-9 associated with skin aging. Our results suggest that SYR has potential value as a cosmetic additive for prevention of skin aging.

Pathological Relationship between Intracellular Superoxide Metabolism and p53 Signaling in Mice

Intracellular superoxide dismutases (SODs) maintain tissue homeostasis via superoxide metabolism. We previously reported that intracellular reactive oxygen species (ROS), including superoxide accumulation caused by cytoplasmic SOD (SOD1) or mitochondrial SOD (SOD2) insufficiency, induced p53 activation in cells. SOD1 loss also induced several age-related pathological changes associated with increased oxidative molecules in mice. To evaluate the contribution of p53 activation for SOD1 knockout (KO) (Sod1-/-) mice, we generated SOD1 and p53 KO (double-knockout (DKO)) mice. DKO fibroblasts showed increased cell viability with decreased apoptosis compared with Sod1-/- fibroblasts. In vivo experiments revealed that p53 insufficiency was not a great contributor to aging-like tissue changes but accelerated tumorigenesis in Sod1-/- mice. Furthermore, p53 loss failed to improve dilated cardiomyopathy or the survival in heart-specific SOD2 conditional KO mice. These data indicated that p53 regulated ROS-mediated apoptotic cell death and tumorigenesis but not ROS-mediated tissue degeneration in SOD-deficient models.

Xanthine Oxidoreductase-Mediated Superoxide Production Is Not Involved in the Age-Related Pathologies in Sod1-Deficient Mice

Reactive oxygen species (ROS) metabolism is regulated by the oxygen-mediated enzyme reaction and antioxidant mechanism within cells under physiological conditions. Xanthine oxidoreductase (XOR) exhibits two inter-convertible forms (xanthine oxidase (XO) and xanthine dehydrogenase (XDH)), depending on the substrates. XO uses oxygen as a substrate and generates superoxide (O2•-) in the catalytic pathway of hypoxanthine. We previously showed that superoxide dismutase 1 (SOD1) loss induced various aging-like pathologies via oxidative damage due to the accumulation of O2•- in mice. However, the pathological contribution of XO-derived O2•- production to aging-like tissue damage induced by SOD1 loss remains unclear. To investigate the pathological significance of O2•- derived from XOR in Sod1-/- mice, we generated Sod1-null and XO-type- or XDH-type-knock-in (KI) double-mutant mice. Neither XO-type- nor XDH-type KI mutants altered aging-like phenotypes, such as anemia, fatty liver, muscle atrophy, and bone loss, in Sod1-/- mice. Furthermore, allopurinol, an XO inhibitor, or apocynin, a nicotinamide adenine dinucleotide phosphate oxidase (NOX) inhibitor, failed to improve aging-like tissue degeneration and ROS accumulation in Sod1-/- mice. These results showed that XOR-mediated O2•- production is relatively uninvolved in the age-related pathologies in Sod1-/- mice.

The effect of Q-switched 1064-nm Nd: YAG laser on skin barrier and collagen synthesis via miR-663a to regulate TGFβ1/smad3/p38MAPK pathway

BACKGROUND

Our previous research found that Q-switched 1064-nm Nd: YAG laser (1064-QSNYL) induces skin collagen synthesis by activating TGFβ1/Smad3/p38MAPKs pathway. Moreover, a lot of studies shown that MicroRNAs (miRNAs) contribute to regulate collagen synthesis and skin barrier. Therefore, we intend to explore the mechanism of 1064-QSNYL on collagen synthesis and skin barrier through miRNAs.

METHODS

We predicted the upstream miRNAs of TGFβ1 by bioinformatics databases, and verified them through dual-luciferase reporter genes and Western blotting. The expression of collagen, skin barrier-related protein K10 and filaggrin, TIMP-1, and MMP-2 were detected by RT-qPCR and Western blotting, respectively. Moreover, we detected moisture content, elasticity value, TEWL value, SOD vitality, and hydroxyproline content to evaluate skin barrier of mice. H&E staining to observe the change of dermis thickness and inflammation and infiltration of mice skin.

RESULTS

The results shown that TGFβ1 was target gene of miR-663a. Moreover, we found that 1064-QSNYL activated TGFβ1/smad3/p38MAPK pathway by down-regulating the expression of miR-663a in HaCaT, HDF cells, and mice, thereby promoting expression of Collagen I, Collagen IV, TIMP-1, K10, and filaggrin and inhibiting MMP-2. Furthermore, 1064-QSNYL contributed to moisture content, elasticity, SOD vitality, and hydroxyproline content via miR-663a to activate TGFβ1/smad3/p38MAPK pathway.

CONCLUSIONS

In summary, this study found for the first time that 1064-QSNYL contributed to collagen synthesis and skin repair via miR-663a to regulate TGFβ1/smad3/p38MAPK pathway, thereby achieving skin rejuvenation.

Syringaresinol Protects against Type 1 Diabetic Cardiomyopathy by Alleviating Inflammation Responses, Cardiac Fibrosis, and Oxidative Stress

SCOPE

Syringaresinol (SYR) is a phenolic compound, which could be found in various cereals and medicinal plants. It exerts both anti-inflammatory and antioxidant pharmacological properties. However, little is known about the effect of SYR on modulating diabetic cardiomyopathy. The present study aimed to investigate the pharmacodynamic effect of SYR on diabetic cardiomyopathy and the underlying molecular mechanism.

METHODS AND RESULTS

In STZ-induced type 1 diabetic mice, orally administration with SYR in every other day for 8 weeks significantly improves cardiac dysfunction and preventes cardiac hypertrophy and fibrosis. The macrophage infiltration and oxidative stress biomarkers are also suppressed by SYR without affecting hyperglycemia and body weight. In neonatal cardiomyocytes, high glucose-induced cell apoptosis and fibrosis are potently decreased by SYR, and the inflammatory response and oxidant stress are also alleviated by SYR incubation. Mechanistically, SYR may exert protective effects by restoring suppression of antioxidant kelch-like ECH-associated protein 1 (Keap1)/nuclear factor-E2-related factor 2 (Nrf2) system and abnormal activation of transforming growth factor-β (TGF-β)/mothers against decapentaplegic homolog (Smad) signaling pathway in vitro and in vivo.

CONCLUSION

The results indicated that SYR could be a potential therapeutic agent for the treatment of diabetic cardiomyopathy by inhibiting inflammation, fibrosis, and oxidative stress. The signaling pathway of Keap1/Nrf2 and TGF-β/Smad could be used as therapeutic targets for diabetic complications.

Syringaresinol Inhibits UVA-Induced MMP-1 Expression by Suppression of MAPK/AP-1 Signaling in HaCaT Keratinocytes and Human Dermal Fibroblasts

Ultraviolet (UV) irradiation induces detrimental changes in human skin which result in photoaging. UV-induced intracellular changes cause degradation of extracellular matrix (ECM). UV-stimulated cleavage of collagen in ECM occurs via matrix metalloproteinases (MMPs). (±)-syringaresinol (SYR), a phytochemical which belongs to the lignan group of polyphenols, was investigated for its ability to reverse the UVA-induced changes in human HaCaT keratinocytes and dermal fibroblasts (HDFs) in vitro. Effect of SYR on UVA-induced changes was investigated by production and activation of MMPs and its transcriptional upstream effectors; mitogen-activated protein kinases (MAPKs) and pro-inflammatory mediators. Levels of expression were determined using ELISA, RT-PCR and immunoblotting. UVA irradiation stimulated the production of MMP-1 and inhibited collagen production. SYR treatment suppressed MMP-1 and enhanced collagen production in UVA-irradiated HaCaT keratinocytes and HDFs. SYR repressed the UV-induced phosphorylation of p38, ERK and JNK MAPKs in HaCaT keratinocytes while only suppressing JNK phosphorylation in HDFs. In addition, SYR was able to inhibit UVA-induced production of inflammatory cytokines; TNF-α, COX-2, IL-1β and IL-6. Moreover, SYR suppressed the activator protein-1 (AP-1), a heterodimer of phosphorylated transcription factors c-Jun and c-Fos. SYR-treatment decreased nuclear levels of activated c-Fos and c-Jun as a mechanism to inhibit UVA-induced transcriptional activities leading to MMP-1 production. In conclusion, current results demonstrated that SYR could inhibit UVA-induced upregulation of MMP-1 by suppressing MAPK/AP-1 signaling in HaCaT keratinocytes and HDFs. Therefore, SYR was suggested as a potential compound with antiphotoaging properties against UVA-induced skin aging.

Copper/Zinc Superoxide Dismutase in Human Skin: Current Knowledge

Superoxide dismutase is widespread in the human body, including skin and its appendages. Here, we focus on human skin copper/zinc superoxide dismutase, the enzyme that protects skin and its appendages against reactive oxygen species. Human skin copper/zinc superoxide dismutase resides in the cytoplasm of keratinocytes, where up to 90% of cellular reactive oxygen species is produced. Factors other than cell type, such as gender, age and diseased state influence its location in skin tissues. We review current knowledge of skin copper/zinc superoxide dismutase including recent studies in an attempt to contribute to solving the question of its remaining unexplained functions. The research described here may be applicable to pathologies associated with oxidative stress. However, recent studies on copper/zinc superoxide dismutase in yeast reveal that its predominant function may be in signaling pathways rather than in scavenging superoxide ions. If confirmed in the skin, novel approaches might be developed to unravel the enzyme's remaining mysteries.

17β-Estradiol Prevents Extracellular Matrix Degradation by Downregulating MMP3 Expression via PI3K/Akt/FOXO3 Pathway

STUDY DESIGN

In vitro studies of the role of 17β-estradiol (E2) and its possible targets in intervertebral disc degeneration (IDD).

OBJECTIVE

To define the regulatory role of E2 in IDD and the potential mechanisms.

SUMMARY OF BACKGROUND DATA

IDD has intricate etiology that is influenced by multiple risk factors. However, the underlying molecular mechanisms of occurrence and progression of IDD are not well elucidated. The degradation of extracellular matrix (ECM) has been extensively observed in IDD. E2 was found to inhibit ECM degradation in human nuleus pulposus cells (HNPCs), but the molecular mechanism remained to be determined.

METHODS

Western blot and qPCR was performed to quantify the expression of target proteins in HNPCs. Luciferase reporter gene assay was applied to detect the effects of E2 and forkhead box O-3 (FOXO3) on matrix metalloproteinases (MMP)-3 promoter activity. Chromatin immunoprecipitation assay analyzed the binding of FOXO3 to MMP-3 and the effect of E2 on this process.

RESULTS

We identified the upregulation of collagen II and aggrecan by E2 independent of time and concentration. And E2 downregulated MMP-3 expression in human nucleus pulposus cells. The phosphorylation of FOXO3 led to the reduction of MMP-3 promoter activity. Furthermore, 17β-estradiol-induced the activation of PI3K/Akt pathway is required for FOXO3 phosphorylated.

CONCLUSION

E2 prevents the degradation of ECM by upregulating collagen II and aggrecan expression via reducing MMP-3 expression in HNPCs, and PI3K/Akt/FOXO3 pathway is dispensable for MMP-3 downregulated. Therefore, E2 protects against IDD by preventing ECM degradation.

LEVEL OF EVIDENCE

3.

SOD1 deficiency alters gastrointestinal microbiota and metabolites in mice

Redox imbalance induces oxidative damage and causes age-related pathologies. Mice lacking the antioxidant enzyme SOD1 (Sod1^-/-) exhibit various aging-like phenotypes throughout the body and are used as aging model mice. Recent reports suggested that age-related changes in the intestinal environment are involved in various diseases. We investigated cecal microbiota profiles and gastrointestinal metabolites in wild-type (Sod1^+/+) and Sod1^-/- mice. Firmicutes and Bacteroidetes were dominant in Sod1^+/+ mice, and most of the detected bacterial species belong to these two phyla. Meanwhile, the Sod1^-/- mice had an altered Firmicutes and Bacteroidetes ratio compared to Sod1^+/+ mice. Among the identified genera, Paraprevotella, Prevotella, Ruminococcus, and Bacteroides were significantly increased, but Lactobacillus was significantly decreased in Sod1^-/- mice compared to Sod1^+/+ mice. The correlation analyses between cecal microbiota and liver metabolites showed that Bacteroides and Prevotella spp. were grouped into the same cluster, and Paraprevotella and Ruminococcus spp. were also grouped as another cluster. These four genera showed a positive and a negative correlation with increased and decreased liver metabolites in Sod1^-/- mice, respectively. In contrast, Lactobacillus spp. showed a negative correlation with increased liver metabolites and a positive correlation with decreased liver metabolites in Sod1^-/- mice. These results suggest that the redox imbalance induced by Sod1 loss alters gastrointestinal microflora and metabolites.

Ginsenoside Rg3-loaded, reactive oxygen species-responsive polymeric nanoparticles for alleviating myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) is a serious threat to the health and lives of patients without any effective therapy. Excessive production of reactive oxygen species (ROS) is considered a principal cause of MIRI. Some natural products, including ginsenoside Rg3 (Rg3), exhibit robust antioxidant activity. However, the lack of an effective delivery strategy for this hydrophobic compound hinders its clinical application. In addition, therapeutic targets and molecular mechanisms of Rg3 require further elucidation to establish its mode of action. This study aimed to generate ROS-responsive nanoparticles (PEG-b-PPS) via the self-assembly of diblock copolymers of poly (ethylene glycol) (PEG) and poly (propylene sulfide) (PPS) and use them for Rg3 encapsulation and delivery. We identified FoxO3a as the therapeutic target of Rg3 using molecular docking and gene silencing. In rat ischemia-reperfusion model, an intramyocardial injection of Rg3-loaded PEG-b-PPS nanoparticles improved the cardiac function and reduced the infarct size. The mechanism of action was established as Rg3 targeting of FoxO3a, which inhibited the promotion of oxidative stress, inflammation, and fibrosis via downstream signaling pathways. In conclusion, this approach, involving ROS-responsive drug release, together with the identification of the target and mechanism of action of Rg3, provided an effective strategy for treating ischemic diseases and oxidative stress and could accelerate the implementation of hydrophobic natural products in clinical applications.