Reactive oxygen species control senescence-associated matrix metalloproteinase-1 through c-Jun-N-terminal kinase

Activating transcription factor 3 induces oxidative stress and genotoxicity, transcriptionally modulating metastasis-related gene expression in human papillomavirus-infected cervical cancer

BACKGROUND

Activating Transcription Factor 3 (ATF3) is known for its tumor-suppressive properties in cervical cancer, particularly through its role in stress response and interactions with human papillomavirus (HPV) oncogenes. This study investigates ATF3's regulatory impact on metastasis-related genes, oxidative stress, and DNA damage in HPV-positive cervical cancer cells.

METHODS

HeLa and Ca Ski cell lines were transfected with ATF3-expressing vectors. Western blotting and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to confirm ATF3 overexpression following transfection. ROS assays and Comet assays assessed the impact of ATF3 on oxidative stress and DNA damage, while RT-qPCR was used to evaluate changes in HPV E6/E7, SHARP1, and MMP1 gene expression.

RESULTS

ATF3 overexpression led to elevated ROS levels (p < 0.02), resulting in oxidative DNA damage. These results demonstrate ATF3's cytotoxic impact on cervical cancer cells through oxidative stress and DNA damage. Additionally, ATF3 overexpression significantly decreased MMP1 expression (p < 0.03), indicating a potential anti-metastatic effect, while SHARP1 and HPV E6/E7 expression levels were not significantly altered, indicating selective gene modulation by ATF3.

CONCLUSION

These findings reveal that ATF3 contributes to tumor suppression in cervical cancer by modulating oxidative stress and DNA damage, selectively targeting genes involved in metastasis. These findings supports ATF3's role in regulating key pathways in HPV-positive cervical cancer cells, providing a basis for further exploration of ATF3 as a target in therapeutic strategies aimed at improving outcomes in cervical cancer.

Toxicity effects of microplastics individually and in combination with Aeromonas hydrophila on freshwater crayfish (Astacus leptodactylous)

Opportunistic pathogens, such as Aeromonas hydrophila, can cause damage to freshwater crayfish (Astacus leptodactylous) in some situations. In addition to direct damage to the body, microplastics (MPs) can also be responsible for transmitting pathogens to the animal. Accordingly, this research was prepared to investigate the effects of MP on the damage caused by A. hydrophila exposure in A. leptodactylous. Hepatic oxidative biomarkers, blood biochemical indices, and clinical signs were investigated in freshwater crayfish co-exposed to MPs (500 and 1000 mg kg-1) and A. hydrophila (5 and 10% of the median lethal dose (LD50)) for 30 days. In the hemolymph of infested crayfish with A. hydrophila, there were no significant changes in glutathione peroxidase activity or total antioxidant level. However, in some of the clinical parameters, exposure to MP alone had a significant effect. Cholesterol levels, glutathione peroxidase, catalase, and the activity of γ-glutamyltransferase reduced, conversely, glucose, malondialdehyde, and aspartate aminotransferase increased. After co-exposure to A. hydrophila and MPs, certain parameters elevated in the hemolymph of crayfish such as glucose, activity of alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase. However, total protein, cholesterol, γ-glutamyltransferase, glutathione peroxidase, catalase activity, and total antioxidants decreased. In contrast, elevation in malondialdehyde content and superoxide dismutase activity was observed in the hepatocytes of crayfish after co-exposure to A. hydrophila and MPs. To summarize, the investigation demonstrated that the interaction of MPs and A. hydrophila in crayfish has a synergistic effect on various factors.

Impaired incorporation of fibronectin into the extracellular matrix during aging exacerbates the senescent state of dermal cells

Fibronectin (Fn) is a ubiquitous extracellular matrix (ECM) glycoprotein that acts as an ECM scaffold organizer and is essential in many biological functions, including tissue repair, differentiation or cancer dissemination. Evidence suggests that the amount of Fn changes during aging. However, how these changes influence the aging process remains unclear. This study aims to understand Fn influence on cell aging. First, we assess the relative level of Fn abundance in both different biopsies of skin donors and replicative senescence cellular model. In skin biopsies, we observed that Fn level decreases with aging in the reticular dermis, while its expression remains relatively stable in the papillary dermis, likely to sustain the dermis-epidermis junction. During replicative senescence, in BJ skin fibroblasts, while intracellular Fn increases, we found that secretion and Fn fibrils formation are less effective. Reduced Fn fibrils leads to disorganization of the ECM. This could be explained by the expression of different Fn isoforms observed in the secretome of senescent cells. Surprisingly, the knockdown of Fn delays the onset of senescence while cultivating cells onto a Fn-coated support promotes it. Taken together, these new insights on the role of Fn during aging may emerge new therapeutic strategies on aged-related diseases.

Phylloquinone improves endothelial function, inhibits cellular senescence, and vascular inflammation

Phylloquinon (PK) and menaquinones (MK) are both naturally occurring compounds belonging to vitamin K group. Present study aimed to comprehensively analyze the influence of PK in several models of vascular dysfunction to determine whether PK has vasoprotective properties, similar to those previously described for MK. Effects of PK and MK on endothelial dysfunction were studied in ApoE/LDLR-/- mice in vivo, in the isolated aorta incubated with TNF, and in vascular cells as regard inflammation and cell senescence (including replicative and stress-induced models of senescence). Moreover, the vascular conversion of exogenous vitamins to endogenous MK-4 was analyzed. PK, as well as MK, given for 8 weeks in diet (10 mg/kg) resulted in comparable improvement in endothelial function in the ApoE/LDLR-/- mice. Similarly, PK and MK prevented TNF-induced impairment of endothelium-dependent vasorelaxation in the isolated aorta. In in vitro studies in endothelial and vascular smooth muscle cells, we identified that both PK and MK displayed anti-senescence effects via decreasing DNA damage while in endothelial cells anti-inflammatory activity was ascribed to the modulation of NFκB activation. The activity of PK and MK was comparable in terms of their effect on senescence and inflammation. Presence of endogenous synthesis of MK-4 from PK in aorta and endothelial and smooth muscle cells suggests a possible involvement of MK in vascular effects of PK. In conclusion, PK and MK display comparable vasoprotective effects, which may be ascribed, at least in part, to the inhibition of cell senescence and inflammation. The vasoprotective effect of PK in the vessel wall can be related to the direct effects of PK, as well as to the action of MK formed from PK in the vascular wall.

MBNL2 promotes aging-related cardiac fibrosis via inhibited SUMOylation of Krüppel-like factor4

Aging-related cardiac fibrosis represents the principal pathological progression in cardiovascular aging. The Muscleblind-like splicing regulator 2 (MBNL2) has been unequivocally established as being associated with cardiovascular diseases. Nevertheless, its role in aging-related cardiac fibrosis remains unexplored. This investigation revealed an elevation of MBNL2 levels in the aged heart and senescent cardiac fibroblasts. Notably, the inhibition of MBNL2 demonstrated a capacity to mitigate H2O2-induced myofibroblast transformation and aging-related cardiac fibrosis. Further mechanistic exploration unveiled that aging heightened the expression of SENP1 and impeded the SUMO1 binding with KLF4, and SUMOylation of KLF4 effectively increased by the inhibition of MBNL2. Additionally, the inhibition of TGF-β1/SMAD3 signaling attenuated the impact of over-expression of MBNL2 in inducing senescence and cardiac fibrosis. MBNL2, by orchestrating SUMOylation of KLF4, upregulating the TGF-β1/SMAD3 signaling pathway, emerges as a significant promoter of aging-related cardiac fibrosis. This discovery identifies a novel regulatory target for managing aging-related cardiac fibrosis.

Deconstructing heterogeneity of replicative senescence in human mesenchymal stem cells at single cell resolution

Following prolonged cell division, mesenchymal stem cells enter replicative senescence, a state of permanent cell cycle arrest that constrains the use of this cell type in regenerative medicine applications and that in vivo substantially contributes to organismal ageing. Multiple cellular processes such as telomere dysfunction, DNA damage and oncogene activation are implicated in promoting replicative senescence, but whether mesenchymal stem cells enter different pre-senescent and senescent states has remained unclear. To address this knowledge gap, we subjected serially passaged human ESC-derived mesenchymal stem cells (esMSCs) to single cell profiling and single cell RNA-sequencing during their progressive entry into replicative senescence. We found that esMSC transitioned through newly identified pre-senescent cell states before entering into three different senescent cell states. By deconstructing this heterogeneity and temporally ordering these pre-senescent and senescent esMSC subpopulations into developmental trajectories, we identified markers and predicted drivers of these cell states. Regulatory networks that capture connections between genes at each timepoint demonstrated a loss of connectivity, and specific genes altered their gene expression distributions as cells entered senescence. Collectively, this data reconciles previous observations that identified different senescence programs within an individual cell type and should enable the design of novel senotherapeutic regimes that can overcome in vitro MSC expansion constraints or that can perhaps slow organismal ageing.

Unripe Pear Extract Suppresses UVB-Induced Skin Photoaging in Hairless Mice and Keratinocytes

Our study aimed to investigate whether unripe pear extract (UP) could provide protection against UVB-induced damage to both mouse skin and keratinocytes. We observed that UVB exposure, a common contributor to skin photoaging, led to wrinkle formation, skin dryness, and inflammation in mice. Nevertheless, these effects were mitigated in the groups of UVB-irradiated mice treated with UP. Moreover, UP treatment at 400 μg/mL increased the antioxidant enzyme activities (sodium dodecyl sulfate, 2.22-fold higher; catalase, 2.91-fold higher; GPx, 1.96-fold higher) along with sphingomyelin (1.58-fold higher) and hyaluronic acid (1.31-fold higher) levels in UVB-irradiated keratinocytes. In the keratinocytes irradiated with UVB, UP 400 μg/mL resulted in reduced cytokine production (TNF-α, 33.2%; IL-1β, 45.3%; IL-6, 33.4%) and the expression of inflammatory pathway-related proteins. The findings indicate that UP has a direct protective effect on UVB-irradiated keratinocytes and is also able to shield against photoaging induced by UVB. Hence, it is suggested that UP could contribute to improved skin health by averting skin photoaging.

The Skin Microbiome: Current Landscape and Future Opportunities

Our skin is the largest organ of the body, serving as an important barrier against the harsh extrinsic environment. Alongside preventing desiccation, chemical damage and hypothermia, this barrier protects the body from invading pathogens through a sophisticated innate immune response and co-adapted consortium of commensal microorganisms, collectively termed the microbiota. These microorganisms inhabit distinct biogeographical regions dictated by skin physiology. Thus, it follows that perturbations to normal skin homeostasis, as occurs with ageing, diabetes and skin disease, can cause microbial dysbiosis and increase infection risk. In this review, we discuss emerging concepts in skin microbiome research, highlighting pertinent links between skin ageing, the microbiome and cutaneous repair. Moreover, we address gaps in current knowledge and highlight key areas requiring further exploration. Future advances in this field could revolutionise the way we treat microbial dysbiosis associated with skin ageing and other pathologies.

AL-Johani N, Alarifi S, Afzal M. Cytotoxicity Mechanisms of Blue-Light-Activated Curcumin in T98G Cell Line: Inducing Apoptosis through ROS-Dependent Downregulation of MMP Pathways

We examined the photodynamic activation of Curcumin under blue light in glioblastoma T98G cells. The therapeutic effect of Curcumin, in both the absence and presence of blue light, was measured by the MTT assay and apoptosis progression using flow cytometry. Fluorescence imaging was carried out to evaluate Curcumin uptake. Photodynamic activation of Curcumin (10 µM), in the presence of blue light, enhanced its cytotoxic effect, resulting in the activation of ROS-dependent apoptotic pathways in T98G cells. The gene expression studies showed the expression of matrixes metalloproteinase 2 (MMP2) and 9 (MMP9) decrease with Curcumin (10 µM) under blue light exposure, indicating possible proteolytic mechanisms. Moreover, the cytometric appearance displayed that the expressions of NF-κB and Nrf2 were found to be increased upon exposure to blue light, which revealed a significant induction of expression of nuclear factor as a result of blue-light-induced oxidative stress and cell death. These data further demonstrate that Curcumin exhibited a photodynamic effect via induction of ROS-mediated apoptosis in the presence of blue light. Our results suggest that the application of blue light enhances the therapeutic efficacy of Curcumin in glioblastoma because of the phototherapeutic effect.

Enzyme-Treated Caviar Prevents UVB Irradiation-Induced Skin Photoaging

For this research article, we investigated the protective effects of enzyme-treated caviar powder extract (CV) in ultraviolet B (UVB)-irradiated hairless mice and keratinocytes by confirming moisturizing-related factors and elasticity-related factors. UVB irradiation induced wrinkle formation, dehydration, oxidative stress, and inflammation in the dorsal skin of mice; however, these were suppressed in the CV-supplemented groups in UVB-irradiated hairless mice. Furthermore, in UVB-irradiated keratinocytes, CV treatment increased the antioxidant enzyme activities and the levels of sphingomyelin and hyaluronic acid and decreased the production of pro-inflammatory cytokines and the expression of IkB-α and p65 phosphorylation. These findings indicate that CV can directly protect keratinocytes against UVB irradiation-induced oxidative stress and inflammation. Therefore, we suggest that CV can protect against UVB-induced skin photoaging. Therefore, we suggest that caviar is effective for skin health by preventing UVB-induced skin photoaging.

A Comprehensive Overview of the Complex Role of Oxidative Stress in Aging, The Contributing Environmental Stressors and Emerging Antioxidant Therapeutic Interventions

Introduction

Aging is a normal, inevitable, irreversible, and progressive process which is driven by internal and external factors. Oxidative stress, that is the imbalance between prooxidant and antioxidant molecules favoring the first, plays a key role in the pathophysiology of aging and comprises one of the molecular mechanisms underlying age-related diseases. However, the oxidative stress theory of aging has not been successfully proven in all animal models studying lifespan, meaning that altering oxidative stress/antioxidant defense systems did not always lead to a prolonged lifespan, as expected. On the other hand, animal models of age-related pathological phenotypes showed a well-correlated relationship with the levels of prooxidant molecules. Therefore, it seems that oxidative stress plays a more complicated role than the one once believed and this role might be affected by the environment of each organism. Environmental factors such as UV radiation, air pollution, and an unbalanced diet, have also been implicated in the pathophysiology of aging and seem to initiate this process more rapidly and even at younger ages.

Aim

The purpose of this review is to elucidate the role of oxidative stress in the physiology of aging and the effect of certain environmental factors in initiating and sustaining this process. Understanding the pathophysiology of aging will contribute to the development of strategies to postpone this phenomenon. In addition, recent studies investigating ways to alter the antioxidant defense mechanisms in order to prevent aging will be presented.

Conclusions

Careful exposure to harmful environmental factors and the use of antioxidant supplements could potentially affect the biological processes driving aging and slow down the development of age-related diseases. Maybe a prolonged lifespan could not be achieved by this strategy alone, but a longer healthspan could also be a favorable target.

Single-cell transcriptomics identifies premature aging features of TERC-deficient mouse brain and bone marrow

Aging is a progressive loss of physiological function and increased susceptibility to major pathologies. Degenerative diseases in both brain and bone including Alzheimer disease (AD) and osteoporosis are common in aging groups. TERC is RNA component of telomerase, and its deficiency accelerates aging-related phenotypes including impaired life span, organ failure, bone loss, and brain dysfunction. In this study, we investigated the traits of bone marrow-brain cross-tissue communications in young mice, natural aging mice, and premature aging (TERC deficient, TERC-KO) mice by single-cell transcriptome sequencing. Differentially expressed gene analysis of brain as well as bone marrow between premature aging mouse and young mouse demonstrated aging-related inflammatory response and suppression of neuron development. Further analysis of senescence-associated secretory phenotype (SASP) landscape indicated that TERC-KO perturbation was enriched in oligodendrocyte progenitor cells (OPCs) and hematopoietic stem and progenitor cells (HSPC). Series of inflammatory associated myeloid cells was activated in premature aging mice brain and bone marrow. Cross-tissue comparison of TERC-KO mice brain and bone marrow illustrated obvious ligand-receptor communications between brain glia cells, macrophages, and bone marrow myeloid cells in premature aging-induced inflammation. Enrichment of co-regulation modules between brain and bone marrow identified premature aging response genes such as Dusp1 and Ifitm3. Our study provides a rich resource for understanding premature aging-associated perturbation in brain and bone marrow and supporting myeloid cells and endothelial cells as promising therapy targeting for age-related brain-bone diseases.

Oxidative Stress and Redox Signaling in the Pathophysiology of Liver Diseases

The increased production of derivatives of molecular oxygen and nitrogen in the form of reactive oxygen species (ROS) and reactive nitrogen species (RNS) lead to molecular damage called oxidative stress. Under normal physiological conditions, the ROS generation is tightly regulated in different cells and cellular compartments. Any disturbance in the balance between the cellular generation of ROS and antioxidant balance leads to oxidative stress. In this article, we discuss the sources of ROS (endogenous and exogenous) and antioxidant mechanisms. We also focus on the pathophysiological significance of oxidative stress in various cell types of the liver. Oxidative stress is implicated in the development and progression of various liver diseases. We narrate the master regulators of ROS-mediated signaling and their contribution to liver diseases. Nonalcoholic fatty liver diseases (NAFLD) are influenced by a "multiple parallel-hit model" in which oxidative stress plays a central role. We highlight the recent findings on the role of oxidative stress in the spectrum of NAFLD, including fibrosis and liver cancer. Finally, we provide a brief overview of oxidative stress biomarkers and their therapeutic applications in various liver-related disorders. Overall, the article sheds light on the significance of oxidative stress in the pathophysiology of the liver. © 2022 American Physiological Society. Compr Physiol 12:3167-3192, 2022.

Saponins of Korean Red Ginseng May Protect Human Skin from Adipokine-Associated Inflammation and Pigmentation Resulting from Particulate Matter Exposure

Background: Exposure to airborne particulate matter (PM) is an ever-increasing concern worldwide. Strategies to counter the detrimental effects that follow cutaneous exposure to PM, such as induction of pigmentation, inflammation, and alterations in adipokine profile, need to be investigated further. Korean red ginseng (KRG) extracts and individual ingredients have been demonstrated to play an effective role in suppression of ROS, inflammation, and resultant skin aging. In addition, recent investigations revealed that Rg3 and Rf saponins work as antimelanogenic agents. In this study, we investigated whether saponins of KRG can protect against or reverse the PM-induced detrimental effects. Methods: The biological effects of PM and saponins were evaluated both in vitro and ex vivo. Cell viability and intracellular ROS levels were determined in normal human epidermal melanocytes (NHMs), human epidermal keratinocytes (NHKs), and their cocultures. Experiments to demonstrate the protective properties of saponins against consequences of exposure to PM were performed. Melanin assay, quantitative real-time PCR, and Western blotting were carried out to determine the effects on melanogenesis and the implicated molecular signaling pathways. Results: Exposure to PM resulted in decreased keratinocyte viability, which was coupled with augmented oxidative stress. These changes were attenuated by treatment with saponins. PM exposure resulted in increased expression of leptin, which was reduced by saponins. Moreover, PM exposure led to increased melanin production in a coculture model, which was mitigated by treatment with saponins. Treatment with saponins resulted in a decrease in matrix metalloproteinase (MMP) levels after exposure to PM. Conclusion: Saponins of KRG can protect the skin from the harmful effects of PM exposure by reducing levels of ROS, leptin, inflammatory cytokines, and melanin.

Effect of microplastics on Yersinia ruckeri infection in rainbow trout (Oncorhynchus mykiss)

Exposure to microorganisms such as Yersinia ruckeri can significantly affect bacterial infections in fish. Microplastics (MPs) may predispose fish to infection and act as carriers in pathogen transmission. Therefore, this study is designed to evaluate MPs' effect on damage caused by exposure to Y. ruckeri in rainbow trout. In this study, blood biochemical parameters and hepatic oxidative biomarkers as clinical signs were measured in the fish co-exposed to Y. ruckeri (5 and 10% the median lethal dose (LD₅₀)) and MPs (500 and 1000 mg Kg^-1) for 30 days. There were no significant changes in the creatinine, triglyceride, cholesterol levels, and glutamic-pyruvic transaminase activity in the blood of fish infected with Y. ruckeri. In contrast, exposure to MPs had a significant effect on most clinical parameters. The total protein, albumin, globulin, total immunoglobulins, high-density lipoprotein, low-density lipoprotein, cholesterol levels, and γ-glutamyltransferase activity decreased, whereas glucose, triglyceride, and creatinine levels, and glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, alkaline phosphatase, and lactate dehydrogenase activities increased in the plasma of fish after co-exposure to MPs and Y. ruckeri. Dietary MPs combined with a Y. ruckeri challenge decreased catalase and glutathione peroxidase activities, and total antioxidant levels. However, superoxide dismutase activity and malondialdehyde contents increased in the hepatocyte of fish co-exposed to MPs and Y. ruckeri. This study suggests that fish exposure to MPs and simultaneous challenge with Y. ruckeri could synergistically affect clinical parameters.

Protective effects of coenzyme Q10 on cell damage induced by hydrogen peroxides in cultured skin fibroblasts

Cellular senescence is an intricate and multifactorial phenomenon, which is characterized by an irreversible cellular growth arrest, it is caused in response to irretrievably DNA damage, telomere shorting, activation of oncogene, and oxidative stress. Human diploid fibroblasts are a well-established experimental model for premature senescence-related studies, and exposure of fibroblasts to H₂O₂ is widely used as a SIPS model. Recently, it has been reported many studies of CoQ₁₀ as to anti-aging effects, however the effect of CoQ₁₀ on H₂O₂-induced SIPS model of human skin fibroblasts has not been understood. So that, we investigated that human skin fibroblasts were used to investigate the prevention effect of CoQ₁₀ against H₂O₂-induced SIPS model. We created SIPS model fibroblasts with treatment of 100 μM H₂O₂ for 2 h. In this study, CoQ₁₀ also increased cell viability and mRNA levels of type I, IV collagen and protein level of type I collagen. Moreover, it is shown that CoQ₁₀ suppressed oxidative stress, degradation of collagen by increasing MMP expression, and decreasing senescence-associated phenotypes (e.g. SA-βgal positive staining and SASP) for preventing skin aging via H₂O₂-induced SIPS model. These results suggested that CoQ₁₀ has possibility to be contributory for extension of healthy life expectancy in Japan.

The anti-wrinkles properties of sodium acetylated hyaluronate

BACKGROUND

Intrinsic aging promotes wrinkles formation by an imbalance between matrix synthesis/degradation in favor of degradation. This is accelerated by the exposome leading to overproduction of protease and fewer remodeling.

OBJECTIVE

Protecting the integrity of extracellular matrix appears as the most efficient anti-aging solution. We developed a grafted HA specifically designed to get anti-aging property due to a specific molecular weight and acetylation degree.

METHODS

A transcriptomic analysis was performed on fibroblasts, followed by a measurement of MMP secretion and subsequent effect on collagen degradation. MMP expression in skin explants concerned by chronobiological and extrinsic aging was analyzed by immunostaining. A clinical study was conducted on volunteers presenting wrinkles on face to evaluate flash reduction of wrinkles after 6 h of application by profilometry and anti-aging efficacy after 2 months by VISIA^® CR2.3.

RESULTS

Transcriptomic analysis evidenced an inhibition of MMP gene expression with acetylated HA, confirmed by an inhibition of MMPs release by fibroblasts, and a protection of type I collagen against degradation. We confirmed the reduction of MMPs in mature skin and in skin explants exposed to UV and urban dust. We demonstrated during clinical studies the flash reduction effect of acetylated HA on crow's feet wrinkles and a filling of nasogenian areas 6 h after application, and a wrinkles number reduction on nasogenian area up to 2 months of application.

CONCLUSION

We developed a new grafted HA owing protective properties against ECM degradation induced by chronobiological and extrinsic aging, leading to a significant and efficient anti-wrinkles effect.

A standardized extract of Asparagus officinalis stem improves HSP70-mediated redox balance and cell functions in bovine cumulus-granulosa cells

Heat shock (HS) protein 70 (HSP70), a well-known HS-induced protein, acts as an intracellular chaperone to protect cells against stress conditions. Although HS induces HSP70 expression to confer stress resistance to cells, HS causes cell toxicity by increasing reactive oxygen species (ROS) levels. Recently, a standardized extract of Asparagus officinalis stem (EAS), produced from the byproduct of asparagus, has been shown to induce HSP70 expression without HS and regulate cellular redox balance in pheochromocytoma cells. However, the effects of EAS on reproductive cell function remain unknown. Here, we investigated the effect of EAS on HSP70 induction and oxidative redox balance in cultured bovine cumulus-granulosa (CG) cells. EAS significantly increased HSP70 expression; however, no effect was observed on HSP27 and HSP90 under non-HS conditions. EAS decreased ROS generation and DNA damage and increased glutathione (GSH) synthesis under both non-HS and HS conditions. Moreover, EAS synergistically increased HSP70 and HSF1 expression and increased progesterone levels in CG cells. Treatment with an HSP70 inhibitor significantly decreased GSH level, increased ROS level, and decreased HSF1, Nrf2, and Keap1 expression in the presence of EAS. Furthermore, EAS significantly increased progesterone synthesis. Thus, EAS improves HSP70-mediated redox balance and cell function in bovine CG cells.

Pulmonary arterial hypertension and flavonoids: A role in treatment

Pulmonary arterial hypertension (PAH) is a high mortality progressive pulmonary vascular disease that can lead to right heart failure. The use of clinical drugs for the treatment of PAH is limited to a great extent because of its single target and high price. Flavonoids are widely distributed in nature, and have been found in fruits, vegetables, and traditional Chinese medicine. They have diverse biological activities and various pharmacological effects such as antitumor, antioxidation, and anti-inflammatory. This review summarizes the progress in pharmacodynamics and mechanism of flavonoids in the treatment of PAH in recent years, in order to provide some theoretical references for relevant researchers.

Targeting senescent cells and tumor therapy (Review)

Cell senescence is caused by the activation of cell cycle inhibition pathways induced by an accumulation of cellular damage, where cells permanently leave the cell cycle. Senescent cells undergo changes in cell morphology, transcription, protein homeostasis, metabolism and other characteristic alterations. At the same time, senescent cells are able to resist apoptosis and accumulate in multiple organs and tissues in vivo. Senescent cells are capable of activating inflammatory factor secretion pathways, generating local, non-infectious inflammatory microenvironments within tissues, leading to organ degeneration and the development of aging-associated diseases. A large number of recently published studies have demonstrated that removing senescent cells from the body delays the occurrence of various aging-associated diseases. Therefore, the targeted killing of senescent cells potentially has important clinical applications in the treatment of various aging-associated diseases, aiming to improve the life span of patients. The present review summarizes recent progress that has been made in the field of senescent cell clearance and various anti-aging strategies. The history of cell senescence research is briefly reviewed, along with the association between cell senescence and tumor therapy. Furthermore, the potential of senescent cells to be used as therapeutic targets in various senescence-associated diseases is primarily discussed, and the limitations, as well as the future prospects of this line of research, are reviewed.

Inonotus obliquus Extracts Decreased Expression of MMP1 mRNA via JNK-AP-1 Axis

Inonotus obliquus, which is parasitic on birch and other trees, is a fungus in the family Hymenochaetaceae. In this study, we investigated whether Inonotus obliquus extracts used in traditional medicine were decreased in the expression of matrix metalloproteinases-1 (MMP-1) in the normal human dermal fibroblasts. As shown in our results, extracts of Inonotus obliquus decreased MMP1 expression in oxidative stress-exposed normal human dermal fibroblasts. Additionally, Inonotus obliquus extracts decreased AP-1 transcriptional activity and phospho-JNK in oxidative stress-exposed normal human dermal fibroblasts. Oxidative stress mediated the elevation of MMP1 mRNA expression and was well regulated by the JNK-AP-1 axis. Therefore, the results suggest that Inonotus obliquus extracts decreased MMP1 mRNA expression by regulating JNK-AP-1 axis. Additionally, Inonotus obliquus extracts have the potential to reduce collagen destruction and the formation of wrinkles and to be used as a cosmetic ingredient.

In vitro modulation of extracellular matrix genes by stingless bee honey in cellular aging of human dermal fibroblast cells

This study determined the antiaging effect of stingless bee honey on the expression of extracellular matrix genes. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was performed for determination of optimum concentration and incubation time of stingless bee honey. Gene expression of matrix metalloproteinase-1 (MMP-1) and collagen type Ⅰ (COL1A1) were analyzed using real time reverse transcriptase polymerase chain reaction technique. Incubation with stingless bee honey at concentration of 0.02% for 72 hr showed significant increase in the viability of human fibroblast cells. Stingless bee honey significantly downregulates metalloproteinase-1 gene expression in both pre-senescence and senescence fibroblast cells and upregulates collagen type Ⅰ gene expression in senescence fibroblast cells. In conclusion, stingless bee honey potentially delayed skin aging through modulation of extracellular matrix genes. PRACTICAL APPLICATIONS: Changes of the extracellular matrix regulation promote skin aging. Stingless bee honey is a good source of natural antioxidant which potentially delays skin aging. This study demonstrated that stingless bee honey beneficially increases collagen type Ⅰ expression and decreases MMP-1 expression during cellular aging of human dermal fibroblast cells.

Loss of epitranscriptomic control of selenocysteine utilization engages senescence and mitochondrial reprogramming☆

Critically important to the maintenance of the glutathione (GSH) redox cycle are the activities of many selenocysteine-containing GSH metabolizing enzymes whose translation is controlled by the epitranscriptomic writer alkylation repair homolog 8 (ALKBH8). ALKBH8 is a tRNA methyltransferase that methylates the wobble uridine of specific tRNAs to regulate the synthesis of selenoproteins. Here we demonstrate that a deficiency in the writer ALKBH8 (Alkbh8^def), alters selenoprotein levels and engages senescence, regulates stress response genes and promotes mitochondrial reprogramming. Alkbh8^def mouse embryonic fibroblasts (MEFs) increase many hallmarks of senescence, including senescence associated β-galactosidase, heterocromatic foci, the cyclin dependent kinase inhibitor p16^Ink4a, markers of mitochondrial dynamics as well as the senescence associated secretory phenotype (SASP). Alkbh8^def cells also acquire a stress resistance phenotype that is accompanied by an increase in a number redox-modifying transcripts. In addition, Alkbh8^def MEFs undergo a metabolic shift that is highlighted by a striking increase in the level of uncoupling protein 2 (UCP2) which enhances oxygen consumption and promotes a reliance on glycolytic metabolism. Finally, we have shown that the Alkbh8 deficiency can be exploited and corresponding MEFs are killed by glycolytic inhibition. Our work demonstrates that defects in an epitransciptomic writer promote senescence and mitochondrial reprogramming and unveils a novel adaptive mechanism for coping with defects in selenocysteine utilization.

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Deficiencies in selenocysteine utilization engages cellular senescence and the senescence associated secretory phenotype.

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Alkbh8 deficiency promotes mitochondrial elongation, increased oxygen consumption and a reliance on glycolytic metabolism.

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Cellular adaptions to Alkbh8 deficiency confer stress resistance.

Iron and iron-dependent reactive oxygen species in the regulation of macrophages and fibroblasts in non-healing chronic wounds

Chronic wounds pose a stern challenge to health care systems with growing incidence especially in the aged population. In the presence of increased iron concentrations, recruitment of monocytes from the circulation and activation towards ROS and RNS releasing M1 macrophages together with the persistence of senescent fibroblasts at the wound site are significantly enhanced. This unrestrained activation of pro-inflammatory macrophages and senescent fibroblasts has increasingly been acknowledged as main driver causing non-healing wounds. In a metaphor, macrophages act like stage directors of wound healing, resident fibroblasts constitute main actors and increased iron concentrations are decisive parts of the libretto, and - if dysregulated - are responsible for the development of non-healing wounds. This review will focus on recent cellular and molecular findings from chronic venous leg ulcers and diabetic non-healing wounds both constituting the most common pathologies often resulting in limb amputations of patients. This not only causes tremendous suffering and loss of life quality, but is also associated with an increase in mortality and a major socio-economic burden. Despite recent advances, the underlying molecular mechanisms are not completely understood. Overwhelming evidence shows that reactive oxygen species and the transition metal and trace element iron at pathological concentrations are crucially involved in a complex interplay between cells of different histogenetic origin and their extracellular niche environment. This interplay depends on a variety of cellular, non-cellular biochemical and cell biological mechanisms. Here, we will highlight recent progress in the field of iron-dependent regulation of macrophages and fibroblasts and related pathologies linked to non-healing chronic wounds.

A prospect of cell immortalization combined with matrix microenvironmental optimization strategy for tissue engineering and regeneration

Cellular senescence is a major hurdle for primary cell-based tissue engineering and regenerative medicine. Telomere erosion, oxidative stress, the expression of oncogenes and the loss of tumor suppressor genes all may account for the cellular senescence process with the involvement of various signaling pathways. To establish immortalized cell lines for research and clinical use, strategies have been applied including internal genomic or external matrix microenvironment modification. Considering the potential risks of malignant transformation and tumorigenesis of genetic manipulation, environmental modification methods, especially the decellularized cell-deposited extracellular matrix (dECM)-based preconditioning strategy, appear to be promising for tissue engineering-aimed cell immortalization. Due to few review articles focusing on this topic, this review provides a summary of cell senescence and immortalization and discusses advantages and limitations of tissue engineering and regeneration with the use of immortalized cells as well as a potential rejuvenation strategy through combination with the dECM approach.

Radiation-Induced Alterations in the Recurrent Glioblastoma Microenvironment: Therapeutic Implications

Glioblastoma (GBM) is uniformly fatal with a median survival of just over 1 year, despite best available treatment including radiotherapy (RT). Impacts of prior brain RT on recurrent tumors are poorly understood, though increasing evidence suggests RT-induced changes in the brain microenvironment contribute to recurrent GBM aggressiveness. The tumor microenvironment impacts malignant cells directly and indirectly through stromal cells that support tumor growth. Changes in extracellular matrix (ECM), abnormal vasculature, hypoxia, and inflammation have been reported to promote tumor aggressiveness that could be exacerbated by prior RT. Prior radiation may have long-term impacts on microglia and brain-infiltrating monocytes, leading to lasting alterations in cytokine signaling and ECM. Tumor-promoting CNS injury responses are recapitulated in the tumor microenvironment and augmented following prior radiation, impacting cell phenotype, proliferation, and infiltration in the CNS. Since RT is vital to GBM management, but substantially alters the tumor microenvironment, we here review challenges, knowledge gaps, and therapeutic opportunities relevant to targeting pro-tumorigenic features of the GBM microenvironment. We suggest that insights from RT-induced changes in the tumor microenvironment may provide opportunities to target mechanisms, such as cellular senescence, that may promote GBM aggressiveness amplified in previously radiated microenvironment.

Cellular Senescence, Neurological Function, and Redox State

SIGNIFICANCE

Cellular senescence, characterized by permanent cell cycle arrest, has been extensively studied in mitotic cells such as fibroblasts. However, senescent cells have also been observed in the brain. Even though it is recognized that cellular energetic metabolism and redox homeostasis are perturbed in the aged brain and neurodegenerative diseases (NDDs), it is still unknown which alterations in the overall physiology can stimulate cellular senescence induction and their relationship with the former events. Recent Advances: Recent findings have shown that during prolonged inflammatory and pathologic events, the blood-brain barrier could be compromised and immune cells might enter the brain; this fact along with the brain's high oxygen dependence might result in oxidative damage to macromolecules and therefore senescence induction. Thus, cellular senescence in different brain cell types is revised here.

CRITICAL ISSUES

Most information related to cellular senescence in the brain has been obtained from research in glial cells since it has been assumed that the senescent phenotype is a feature exclusive to mitotic cells. Nevertheless, neurons with senescence hallmarks have been observed in old mouse brains. Therefore, although this is a controversial topic in the field, here we summarize and integrate the observations from several studies and propose that neurons indeed senesce.

FUTURE DIRECTIONS

It is still unknown which alterations in the overall metabolism can stimulate senescence induction in the aged brain, what are the mechanisms and signaling pathways, and what is their relationship to NDD development. The understanding of these processes will expose new targets to intervene age-associated pathologies.-Antioxid. Redox Signal. 28, 1704-1723.

The Contribution of Oxidative Stress and Inflamm-Aging in Human and Equine Asthma

Aging is associated with a dysregulation of the immune system, leading to a general pro-inflammatory state of the organism, a process that has been named inflamm-aging. Oxidative stress has an important role in aging and in the regulation of immune responses, probably playing a role in the development of age-related diseases. The respiratory system function physiologically declines with the advancement of age. In elderly asthmatic patients, this may contribute to disease expression. In this review, we will focus on age-related changes affecting the immune system and in respiratory structure and function that could contribute to asthma occurrence, and/or clinical presentation in the elderly. Also, naturally occurring equine asthma will be discussed as a possible model for studying the importance of oxidative stress and immun-aging/inflamm-aging in humans.

Pathways that Regulate ROS Scavenging Enzymes, and Their Role in Defense Against Tissue Destruction in Periodontitis

Periodontitis, an inflammatory disease that affects the tissues surrounding the teeth, is a common disease worldwide. It is caused by a dysregulation of the host inflammatory response to bacterial infection, which leads to soft and hard tissue destruction. In particular, it is the excessive inflammation in response to bacterial plaque that leads to the release of reactive oxygen species (ROS) from neutrophils, which, then play a critical role in the destruction of periodontal tissue. Generally, ROS produced from immune cells exhibit an anti-bacterial effect and play a role in host defense and immune regulation. Excessive ROS, however, can exert cytotoxic effects, cause oxidative damage to proteins, and DNA, can interfere with cell growth and cell cycle progression, and induce apoptosis of gingival fibroblasts. Collectively, these effects enable ROS to directly induce periodontal tissue damage. Some ROS also act as intracellular signaling molecules during osteoclastogenesis, and can thus also play an indirect role in bone destruction. Cells have several protective mechanisms to manage such oxidative stress, most of which involve production of cytoprotective enzymes that scavenge ROS. These enzymes are transcriptionally regulated via NRF2, Sirtuin, and FOXO. Some reports indicate an association between periodontitis and these cytoprotective enzymes' regulatory axes, with superoxide dismutase (SOD) the most extensively investigated. In this review article, we discuss the role of oxidative stress in the tissue destruction manifest in periodontitis, and the mechanisms that protect against this oxidative stress.

Redox control of senescence and age-related disease

The signaling networks that drive the aging process, associated functional deterioration, and pathologies has captured the scientific community's attention for decades. While many theories exist to explain the aging process, the production of reactive oxygen species (ROS) provides a signaling link between engagement of cellular senescence and several age-associated pathologies. Cellular senescence has evolved to restrict tumor progression but the accompanying senescence-associated secretory phenotype (SASP) promotes pathogenic pathways. Here, we review known biological theories of aging and how ROS mechanistically control senescence and the aging process. We also describe the redox-regulated signaling networks controlling the SASP and its important role in driving age-related diseases. Finally, we discuss progress in designing therapeutic strategies that manipulate the cellular redox environment to restrict age-associated pathology.

Featured Article: Nanoenhanced matrix metalloproteinase-responsive delivery vehicles for disease resolution and imaging

The wide array of proteases, including matrix metalloproteinases, produced in response to many pathogenic insults, confers a unique proteolytic signature which is often disease specific and provides a potential therapeutic target for drug delivery. Here we propose the use of collagen-based nanoenhanced matrix metalloproteinase-responsive delivery vehicles that display matrix metalloproteinase-specific degradation in diverse in vitro models of proteolysis. We demonstrate that collagen particles comprised of protease substrates (primarily collagen) can be made of uniform size and loaded efficiently with assorted cargo including fluorescently labeled mesoporous silica, magnetic nanoparticles, proteins and antioxidants. We also demonstrate that pathologic concentrations of proteases produced in situ or in vitro display protease-specific cargo release. Additionally, we show that the collagen-based particles display bright fluorescence when loaded with a fluorophore, and have the potential to be used as vehicles for targeted delivery of drugs or imaging agents to regions of high proteolytic activity.

Senescence in chronic allograft nephropathy

Despite increasing numbers of patients on dialysis, the numbers of renal transplants performed yearly have remained relatively static. During the last 50 years, there have been many advances in the pharmacology of prevention of organ rejection. However, most patients will suffer from a slow but steady decline in renal function leading to graft loss. The most common cause of long-term graft loss is chronic allograft nephropathy (CAN). Therefore, elucidating and understanding the mechanisms involved in CAN is crucial for achieving better posttransplant outcomes. It is thought that the development of epithelial to mesenchymal transition (EMT) in proximal tubules is one of the first steps towards CAN, and has been shown to be a result of cellular senescence. Cells undergoing senescence acquire a senescence associated secretory phenotype (SASP) leading to the production of interleukin-1 alpha (IL-1α), which has been implicated in several degenerative and inflammatory processes including renal disease. A central mediator in SASP activation is the production of reactive oxygen species (ROS), which are produced in response to numerous physiological and pathological stimuli. This review explores the connection between SASP and the development of EMT/CAN in an effort to suggest future directions for research leading to improved long-term graft outcomes.

Enzyme-Treated Asparagus Extract Attenuates Hydrogen Peroxide-Induced Matrix Metalloproteinase-9 Expression in Murine Skin Fibroblast L929 Cells

Enzyme-treated asparagus extract (ETAS) exerts a wide variety of beneficial biological actions including facilitating anti-cortisol stress and neurological anti-aging responses. However, the anti-skin aging effects of ETAS remain to be elucidated. Reactive oxygen species (ROS) play pivotal roles in skin aging. Increased ROS levels in fibroblasts in response to ultraviolet irradiation activate c-Jun N-terminal kinase (JNK) and its downstream transcription factor activator protein-1 (AP-1), and the resultant gene expression of matrix metalloproteinase (MMP) isoforms accelerates collagen breakdown in the dermis. Therefore, we explored whether ETAS has anti-skin aging effects by attenuating the oxidative stress responses in fibroblasts. Simultaneous treatment of murine skin L929 fibroblasts with hydrogen peroxide (H2O2) and either ETAS or dextrin showed that ETAS significantly suppressed H2O2-induced expression of MMP-9 mRNA as measured by real-time polymerase chain reaction. ETAS also clearly suppressed H2O2-stimulated phosphorylation of c-Jun (AP-1 subunit) and JNK as determined by Western blot. However, ETAS did not affect the increased amounts of carbonyl proteins in response to H2O2, also as determined by Western blotting. These results suggest that ETAS diminishes cellular responsiveness to ROS but does not scavenge ROS. Thus, ETAS has the potential to prevent skin aging through attenuating the oxidative stress responses in dermal fibroblasts.

Polysaccharide Extracted from Laminaria japonica Delays Intrinsic Skin Aging in Mice

This study aimed to determine the effect of topically applied Laminaria polysaccharide (LP) on skin aging. We applied ointment containing LP (10, 25, and 50 μg/g) or vitamin E (10 μg/g) to the dorsal skin of aging mice for 12 months and young control mice for 4 weeks. Electron microscopy analysis of skin samples revealed that LP increased dermal thickness and skin collagen content. Tissue inhibitor of metalloprotease- (TIMP-) 1 expression was upregulated while that of matrix metalloproteinase- (MMP-) 1 was downregulated in skin tissue of LP-treated as compared to untreated aging mice. Additionally, phosphorylation of c-Jun N-terminal kinase (JNK) and p38 was higher in aging skin than in young skin, while LP treatment suppressed phospho-JNK expression. LP application also enhanced the expression of antioxidative enzymes in skin tissue, causing a decrease in malondialdehyde levels and increases in superoxide dismutase, catalase, and glutathione peroxidase levels relative to those in untreated aging mice. These results indicate that LP inhibits MMP-1 expression by preventing oxidative stress and JNK phosphorylation, thereby delaying skin collagen breakdown during aging.

Lung extracellular matrix and redox regulation

Pulmonary fibrosis affects millions worldwide and, even though there has been a significant investment in understanding the processes involved in wound healing and maladaptive repair, a complete understanding of the mechanisms responsible for lung fibrogenesis eludes us, and interventions capable of reversing or halting disease progression are not available. Pulmonary fibrosis is characterized by the excessive expression and uncontrolled deposition of extracellular matrix (ECM) proteins resulting in erosion of the tissue structure. Initially considered an 'end-stage' process elicited after injury, these events are now considered pathogenic and are believed to contribute to the course of the disease. By interacting with integrins capable of signal transduction and by influencing tissue mechanics, ECM proteins modulate processes ranging from cell adhesion and migration to differentiation and growth factor expression. In doing so, ECM proteins help orchestrate complex developmental processes and maintain tissue homeostasis. However, poorly controlled deposition of ECM proteins promotes inflammation, fibroproliferation, and aberrant differentiation of cells, and has been implicated in the pathogenesis of pulmonary fibrosis, atherosclerosis and cancer. Considering their vital functions, ECM proteins are the target of investigation, and oxidation-reduction (redox) reactions have emerged as important regulators of the ECM. Oxidative stress invariably accompanies lung disease and promotes ECM expression directly or through the overproduction of pro-fibrotic growth factors, while affecting integrin binding and activation. In vitro and in vivo investigations point to redox reactions as targets for intervention in pulmonary fibrosis and related disorders, but studies in humans have been disappointing probably due to the narrow impact of the interventions tested, and our poor understanding of the factors that regulate these complex reactions. This review is not meant to provide a comprehensive review of this field, but rather to highlight what has been learned and to raise interest in this area in need of much attention.

The Measurement of Reversible Redox Dependent Post-translational Modifications and Their Regulation of Mitochondrial and Skeletal Muscle Function

Mitochondrial oxidative stress is a common feature of skeletal myopathies across multiple conditions; however, the mechanism by which it contributes to skeletal muscle dysfunction remains controversial. Oxidative damage to proteins, lipids, and DNA has received the most attention, yet an important role for reversible redox post-translational modifications (PTMs) in pathophysiology is emerging. The possibility that these PTMs can exert dynamic control of muscle function implicates them as a mechanism contributing to skeletal muscle dysfunction in chronic disease. Herein, we discuss the significance of thiol-based redox dependent modifications to mitochondrial, myofibrillar, and excitation-contraction (EC) coupling proteins with an emphasis on how these changes could alter skeletal muscle performance under chronically stressed conditions. A major barrier to a better mechanistic understanding of the role of reversible redox PTMs in muscle function is the technical challenges associated with accurately measuring the changes of site-specific redox PTMs. Here we will critically review current approaches with an emphasis on sample preparation artifacts, quantitation, and specificity. Despite these challenges, the ability to accurately quantify reversible redox PTMs is critical to understanding the mechanisms by which mitochondrial oxidative stress contributes to skeletal muscle dysfunction in chronic diseases.

Diphlorethohydroxycarmalol Suppresses Ultraviolet B-Induced Matrix Metalloproteinases via Inhibition of JNK and ERK Signaling in Human Keratinocytes

Skin aging is the most readily observable process involved in human aging. Ultraviolet B (UVB) radiation causes photo-oxidation via generation of reactive oxygen species (ROS), thereby damaging the nucleus and cytoplasm of skin cells and ultimately leading to cell death. Recent studies have shown that high levels of solar UVB irradiation induce the synthesis of matrix metalloproteinases (MMPs) in skin fibroblasts, causing photo-aging and tumor progression. The MMP family is involved in the breakdown of extracellular matrix in normal physiological processes such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes such as arthritis and metastasis. We investigated the effect of diphlorethohydroxycarmalol (DPHC) against damage induced by UVB radiation in human skin keratinocytes. In UVB-irradiated cells, DPHC significantly reduced expression of MMP mRNA and protein, as well as activation of MMPs. Furthermore, DPHC reduced phosphorylation of ERK and JNK, which act upstream of c-Fos and c-Jun, respectively; consequently, DPHC inhibited the expression of c-Fos and c-Jun, which are key components of activator protein-1 (AP-1, up-regulator of MMPs). Additionally, DPHC abolished the DNA-binding activity of AP-1, and thereby prevented AP-1-mediated transcriptional activation. These data demonstrate that by inactivating ERK and JNK, DPHC inhibits induction of MMPs triggered by UVB radiation.

Impact Assessment of Cigarette Smoke Exposure on Organotypic Bronchial Epithelial Tissue Cultures: A Comparison of Mono-Culture and Coculture Model Containing Fibroblasts

Organotypic 3D cultures of epithelial cells are grown at the air-liquid interface (ALI) and resemble the in vivo counterparts. Although the complexity of in vivo cellular responses could be better manifested in coculture models in which additional cell types such as fibroblasts were incorporated, the presence of another cell type could mask the response of the other. This study reports the impact of whole cigarette smoke (CS) exposure on organotypic mono- and coculture models to evaluate the relevancy of organotypic models for toxicological assessment of aerosols. Two organotypic bronchial models were directly exposed to low and high concentrations of CS of the reference research cigarette 3R4F: monoculture of bronchial epithelial cells without fibroblasts (BR) and coculture with fibroblasts (BRF) models. Adenylate kinase (AK)-based cytotoxicity, cytochrome P450 (CYP) 1A1/1B1 activity, tissue histology, and concentrations of secreted mediators into the basolateral media, as well as transcriptomes were evaluated following the CS exposure. The results demonstrated similar impact of CS on the AK-based cytotoxicity, CYP1A1/1B1 activity, and tissue histology in both models. However, a greater number of secreted mediators was identified in the basolateral media of the monoculture than in the coculture models. Furthermore, annotation analysis and network-based systems biology analysis of the transcriptomic profiles indicated a more prominent cellular stress and tissue damage following CS in the monoculture epithelium model without fibroblasts. Finally, our results indicated that an in vivo smoking-induced xenobiotic metabolism response of bronchial epithelial cells was better reflected from the in vitro CS-exposed coculture model.

Uncoupling of Elastin Complex Receptor during In Vitro Aging Is Related to Modifications in Its Intrinsic Sialidase Activity and the Subsequent Lactosylceramide Production

Degradation of elastin leads to the production of elastin-derived peptides (EDP), which exhibit several biological effects, such as cell proliferation or protease secretion. Binding of EDP on the elastin receptor complex (ERC) triggers lactosylceramide (LacCer) production and ERK1/2 activation following ERC Neu-1 subunit activation. The ability for ERC to transduce signals is lost during aging, but the mechanism involved is still unknown. In this study, we characterized an in vitro model of aging by subculturing human dermal fibroblasts. This model was used to understand the loss of EDP biological activities during aging. Our results show that ERC uncoupling does not rely on Neu-1 or PPCA mRNA or protein level changes. Furthermore, we observe that the membrane targeting of these subunits is not affected with aging. However, we evidence that Neu-1 activity and LacCer production are altered. Basal Neu-1 catalytic activity is strongly increased in aged cells. Consequently, EDP fail to promote Neu-1 catalytic activity and LacCer production in these cells. In conclusion, we propose, for the first time, an explanation for ERC uncoupling based on the age-related alterations of Neu-1 activity and LacCer production that may explain the loss of EDP-mediated effects occurring during aging.

Antioxidant capacity of "Mexican arnica" Heterotheca inuloides Cass natural products and some derivatives: their anti-inflammatory evaluation and effect on C. elegans life span

It has been suggested that the accumulation of biomolecular damage caused by reactive oxygen species (ROS) contributes to aging. The antioxidant activity is related to the ability of certain compounds to protect against the potentially harmful effect of processes or reactions involving ROS. This ability is associated with the termination of free radical propagation in biological systems. From Heterotheca inuloides various compounds which have shown to possess antioxidant capacity and scavenging ROS. The aim of this study was to determine the antioxidant capacity of additional natural components isolated from H. inuloides and some semisynthetic derivatives, their anti-inflammatory activity and the effect on Caenorhabditis elegans nematode life span. Compounds showed ability to inhibit various biological processes such as lipid peroxidation, scavenge nonbiological important oxidants such as ¹O₂, OH^∙, H₂O₂, and HOCl and scavenge non biological stable free radicals (DPPH). Some cadinane type compounds showed possess antioxidant, ROS scavenging capacity, anti-inflammatory activity, and effect on the C. elegans life span. Flavonoid type compounds increased the life of the nematode and quercetin was identified as the compound with the greatest activity. The modification of chemical structure led to a change in the antioxidant capacity, the anti-inflammatory activity, and the survival of the worm.

Autologous Stem Cell Therapy: How Aging and Chronic Diseases Affect Stem and Progenitor Cells

During recent years different types of adult stem/progenitor cells have been successfully applied for the treatment of many pathologies, including cardiovascular diseases. The regenerative potential of these cells is considered to be due to their high proliferation and differentiation capacities, paracrine activity, and immunologic privilege. However, therapeutic efficacy of the autologous stem/progenitor cells for most clinical applications remains modest, possibly because of the attenuation of their regenerative potential in aged patients with chronic diseases such as cardiovascular diseases and metabolic disorders. In this review we will discuss the risk factors affecting the therapeutic potential of adult stem/progenitor cells as well as the main approaches to mitigating them using the methods of regenerative medicine.

Oxidant exposure induces cysteine-rich protein 61 (CCN1) via c-Jun/AP-1 to reduce collagen expression in human dermal fibroblasts

Human skin is a primary target of oxidative stress from reactive oxygen species (ROS) generated from both extrinsic and intrinsic sources. Oxidative stress inhibits the production of collagen, the most abundant protein in skin, and thus contributes to connective tissue aging. Here we report that cysteine-rich protein 61 (CCN1), a negative regulator of collagen production, is markedly induced by ROS and mediates loss of type I collagen in human dermal fibroblasts. Conversely, antioxidant N-acetyl-L-cysteine significantly reduced CCN1 expression and prevented ROS-induced loss of type I collagen in both human dermal fibroblasts and human skin in vivo. ROS increased c-Jun, a critical member of transcription factor AP-1 complex, and increased c-Jun binding to the AP-1 site of the CCN1 promoter. Functional blocking of c-Jun significantly reduced CCN1 promoter and gene expression and thus prevented ROS-induced loss of type I collagen. Targeting the c-Jun/CCN1 axis may provide clinical benefit for connective tissue aging in human skin.

c-Jun N-Terminal Kinases Mediate a Wide Range of Targets in the Metastatic Cascade

Disseminated cancer cells rely on intricate interactions among diverse cell types in the tumor-associated stroma, vasculature, and immune system for survival and growth. Ubiquitous expression of c-Jun N-terminal kinase (jnk) genes in various cell types permits their control of metastasis. In early stages of metastasis, JNKs affect tumor-associated inflammation and angiogenesis as well as tumor cell migration and intravasation. Within the tumor stroma, JNKs are essential for the release of growth factors that promote epithelial-to-mesenchymal transition (EMT) in tumor cells. JNK3, the least ubiquitous isoform, facilitates angiogenesis by increasing endothelial cell migration. Importantly, JNK expression in tumor cells integrates stromal signals to promote tumor cell invasion. However, JNK isoforms differentially regulate migration toward the endothelial barrier. Once tumor cells enter the bloodstream, JNKs increase circulating tumor cell (CTC) survival and homing to tissues. By promoting fibrosis, JNKs improve CTC attachment to the endothelium. Once anchored, JNKs stimulate EMT to facilitate tumor cell extravasation and enhance the secretion of endothelial barrier disrupters. Tumor cells attract barrier-disrupting macrophages by JNK-dependent transcription of macrophage chemoattractant molecules. In the secondary tissue, JNKs are instrumental in the premetastatic niche and stimulate tumor cell proliferation. JNK expression in cancer cells stimulates tissue-remodeling macrophages to improve tumor colonization. However, in T-cells, JNKs alter cytokine production that increases tumor surveillance and inhibits the recruitment of tissue-remodeling macrophages. Therapeutically targeting JNKs for metastatic disease is attractive considering their promotion of metastasis; however, specific JNK tools are needed to determine their definitive actions within the context of the entire metastatic cascade.

Age-related activation of MKK/p38/NF-κB signaling pathway in lung: from mouse to human

We and others previously reported that the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 significantly accumulate with age in mouse lung. This is accompanied by elevated phosphorylation of p38. Here, we further investigate whether aging affects activation of p38 signaling and the inflammatory reaction after exposure to lipopolysaccharide (LPS) in the lungs of mice in vivo and humans ex vivo. The data showed that activation of p38 peaked at 0.5h and then rapidly declined in young (2-month-old) mouse lung, after intranasal inhalation challenge with LPS. In contract, activation of p38 peaked at 24h and was sustained longer in aged (20-month-old) mice. As well as altered p38, activations of its upstream activator MKK and downstream substrate NF-κB were also changed in the lungs of aged mice, which corresponded with the absence in the early phase but delayed increases in concentrations of TNF-α, IL-1β and IL-6. Consistent with the above observations in mice, similar patterns of p38 signaling also occurred in human lungs. Compared with younger lungs from adult-middle aged subjects, the activation of p38, MKK and NF-κB, as well as the production of pro-inflammatory cytokines were significantly increased in the lungs of older subjects ex vivo. Exposure of human lung cells to LPS induced rapid activation of p38, MKK and NF-κB in these cells from adult-middle aged subjects, but not older subjects, with increases in the production of the pro-inflammatory cytokines. The LPS-induced rapid activation in the lung cells from adult-middle aged subjects occurred as early as 0.25h after exposure, and then declined. Compared with adult-middle aged subjects, the LPS exposure did not induce marked changes in the early phase, either in the activation of p38, MKK and NF-κB, or in the production of TNF-α, IL-1β or IL-6 in the lung cells from older subjects. In contrast, these changes occurred relatively late, peaked at 16h and were sustained longer in the lungs of older subjects. These data support the hypothesis that the sustained activation of the p38 signaling pathway at baseline and the absence in the early phase but delayed of p38 signaling pathway response to LPS in the elderly may play important roles in increased susceptibility of aged lungs to inflammatory injury.

Redox-relevant aspects of the extracellular matrix and its cellular contacts via integrins

SIGNIFICANCE

The extracellular matrix (ECM) fulfills essential functions in multicellular organisms. It provides the mechanical scaffold and environmental cues to cells. Upon cell attachment, the ECM signals into the cells. In this process, reactive oxygen species (ROS) are physiologically used as signalizing molecules.

RECENT ADVANCES

ECM attachment influences the ROS-production of cells. In turn, ROS affect the production, assembly and turnover of the ECM during wound healing and matrix remodeling. Pathological changes of ROS levels lead to excess ECM production and increased tissue contraction in fibrotic disorders and desmoplastic tumors. Integrins are cell adhesion molecules which mediate cell adhesion and force transmission between cells and the ECM. They have been identified as a target of redox-regulation by ROS. Cysteine-based redox-modifications, together with structural data, highlighted particular regions within integrin heterodimers that may be subject to redox-dependent conformational changes along with an alteration of integrin binding activity.

CRITICAL ISSUES

In a molecular model, a long-range disulfide-bridge within the integrin β-subunit and disulfide bridges within the genu and calf-2 domains of the integrin α-subunit may control the transition between the bent/inactive and upright/active conformation of the integrin ectodomain. These thiol-based intramolecular cross-linkages occur in the stalk domain of both integrin subunits, whereas the ligand-binding integrin headpiece is apparently unaffected by redox-regulation.

FUTURE DIRECTIONS

Redox-regulation of the integrin activation state may explain the effect of ROS in physiological processes. A deeper understanding of the underlying mechanism may open new prospects for the treatment of fibrotic disorders.

An Intimate Relationship between ROS and Insulin Signalling: Implications for Antioxidant Treatment of Fatty Liver Disease

Oxidative stress damages multiple cellular components including DNA, lipids, and proteins and has been linked to pathological alterations in nonalcoholic fatty liver disease (NAFLD). Reactive oxygen species (ROS) emission, resulting from nutrient overload and mitochondrial dysfunction, is thought to be a principal mediator in NAFLD progression, particularly toward the development of hepatic insulin resistance. In the context of insulin signalling, ROS has a dual role, as both a facilitator and inhibitor of the insulin signalling cascade. ROS mediate these effects through redox modifications of cysteine residues affecting phosphatase enzyme activity, stress-sensitive kinases, and metabolic sensors. This review highlights the intricate relationship between redox-sensitive proteins and insulin signalling in the context of fatty liver disease, and to a larger extent, the importance of reactive oxygen species as primary signalling molecules in metabolically active cells.