Role of haeme oxygenase-1 in resolution of oxidative stress-related pathologies: focus on cardiovascular, lung, neurological and kidney disorders

Mesenchymal stem cells-extracellular vesicles alleviate pulmonary fibrosis by regulating immunomodulators

BACKGROUND

Pulmonary fibrosis (PF) is a chronic interstitial lung disease characterized by fibroblast proliferation and extracellular matrix formation, causing structural damage and lung failure. Stem cell therapy and mesenchymal stem cells-extracellular vesicles (MSC-EVs) offer new hope for PF treatment.

AIM

To investigate the therapeutic potential of MSC-EVs in alleviating fibrosis, oxidative stress, and immune inflammation in A549 cells and bleomycin (BLM)-induced mouse model.

METHODS

The effect of MSC-EVs on A549 cells was assessed by fibrosis markers [collagen I and α-smooth muscle actin (α-SMA), oxidative stress regulators [nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and inflammatory regulators [nuclear factor-kappaB (NF-κB) p65, interleukin (IL)-1β, and IL-2]. Similarly, they were assessed in the lungs of mice where PF was induced by BLM after MSC-EV transfection. MSC-EVs ion PF mice were detected by pathological staining and western blot. Single-cell RNA sequencing was performed to investigate the effects of the MSC-EVs on gene expression profiles of macrophages after modeling in mice.

RESULTS

Transforming growth factor (TGF)-β1 enhanced fibrosis in A549 cells, significantly increasing collagen I and α-SMA levels. Notably, treatment with MSC-EVs demonstrated a remarkable alleviation of these effects. Similarly, the expression of oxidative stress regulators, such as Nrf2 and HO-1, along with inflammatory regulators, including NF-κB p65 and IL-1β, were mitigated by MSC-EV treatment. Furthermore, in a parallel manner, MSC-EVs exhibited a downregulatory impact on collagen deposition, oxidative stress injuries, and inflammatory-related cytokines in the lungs of mice with PF. Additionally, the mRNA sequencing results suggested that BLM may induce PF in mice by upregulating pulmonary collagen fiber deposition and triggering an immune inflammatory response. The findings collectively highlight the potential therapeutic efficacy of MSC-EVs in ameliorating fibrotic processes, oxidative stress, and inflammatory responses associated with PF.

CONCLUSION

MSC-EVs could ameliorate fibrosis in vitro and in vivo by downregulating collagen deposition, oxidative stress, and immune-inflammatory responses.

Mesenchymal stem cells-extracellular vesicles alleviate pulmonary fibrosis by regulating immunomodulators

BACKGROUND

Pulmonary fibrosis (PF) is a chronic interstitial lung disease characterized by fibroblast proliferation and extracellular matrix formation, causing structural damage and lung failure. Stem cell therapy and mesenchymal stem cells-extracellular vesicles (MSC-EVs) offer new hope for PF treatment.

AIM

To investigate the therapeutic potential of MSC-EVs in alleviating fibrosis, oxidative stress, and immune inflammation in A549 cells and bleomycin (BLM)-induced mouse model.

METHODS

The effect of MSC-EVs on A549 cells was assessed by fibrosis markers [collagen I and α-smooth muscle actin (α-SMA), oxidative stress regulators [nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and inflammatory regulators [nuclear factor-kappaB (NF-κB) p65, interleukin (IL)-1β, and IL-2]. Similarly, they were assessed in the lungs of mice where PF was induced by BLM after MSC-EV transfection. MSC-EVs ion PF mice were detected by pathological staining and western blot. Single-cell RNA sequencing was performed to investigate the effects of the MSC-EVs on gene expression profiles of macrophages after modeling in mice.

RESULTS

Transforming growth factor (TGF)-β1 enhanced fibrosis in A549 cells, significantly increasing collagen I and α-SMA levels. Notably, treatment with MSC-EVs demonstrated a remarkable alleviation of these effects. Similarly, the expression of oxidative stress regulators, such as Nrf2 and HO-1, along with inflammatory regulators, including NF-κB p65 and IL-1β, were mitigated by MSC-EV treatment. Furthermore, in a parallel manner, MSC-EVs exhibited a downregulatory impact on collagen deposition, oxidative stress injuries, and inflammatory-related cytokines in the lungs of mice with PF. Additionally, the mRNA sequencing results suggested that BLM may induce PF in mice by upregulating pulmonary collagen fiber deposition and triggering an immune inflammatory response. The findings collectively highlight the potential therapeutic efficacy of MSC-EVs in ameliorating fibrotic processes, oxidative stress, and inflammatory responses associated with PF.

CONCLUSION

MSC-EVs could ameliorate fibrosis in vitro and in vivo by downregulating collagen deposition, oxidative stress, and immune-inflammatory responses.

Evolving Strategies for Use of Phytochemicals in Prevention and Long-Term Management of Cardiovascular Diseases (CVD)

This report describes major pathomechanisms of disease in which the dysregulation of host inflammatory processes is a major factor, with cardiovascular disease (CVD) as a primary model, and reviews strategies for countermeasures based on synergistic interaction between various agents, including drugs and generally regarded as safe (GRAS) natural medical material (NMM), such as Ginkgo biloba, spice phytochemicals, and fruit seed flavonoids. The 15 well-defined CVD classes are explored with particular emphasis on the extent to which oxidative stressors and associated ischemia-reperfusion tissue injury contribute to major symptoms. The four major categories of pharmaceutical agents used for the prevention of and therapy for CVD: statins, beta blockers (β-blockers), blood thinners (anticoagulants), and aspirin, are presented along with their adverse effects. Analyses of major cellular and molecular features of drug- and NMM-mediated cardioprotective processes are provided in the context of their development for human clinical application. Future directions of the evolving research described here will be particularly focused on the characterization and manipulation of calcium- and calcineurin-mediated cascades of signaling from cell surface receptors on cardiovascular and immune cells to the nucleus, with the emergence of both protective and pathological epigenetic features that may be modulated by synergistically-acting combinations of drugs and phytochemicals in which phytochemicals interact with cells to promote signaling that reduces the effective dosage and thus (often) toxicity of drugs.

Understanding One Half of the Sex Difference Equation: The Modulatory Effects of Testosterone on Diabetic Cardiomyopathy

Diabetes is a prevalent disease, primarily characterized by high blood sugar (hyperglycemia). Significantly higher rates of myocardial dysfunction have been noted in individuals with diabetes, even in those without coronary artery disease or high blood pressure (hypertension). Numerous molecular mechanisms have been identified through which diabetes contributes to the pathology of diabetic cardiomyopathy, which presents as cardiac hypertrophy and fibrosis. At the cellular level, oxidative stress and inflammation in cardiomyocytes are triggered by hyperglycemia. Although males are generally more likely to develop cardiovascular disease than females, diabetic males are less likely to develop diabetic cardiomyopathy than are diabetic females. One reason for these differences may be the higher levels of serum testosterone in males compared with females. Although testosterone appears to protect against cardiomyocyte oxidative stress and exacerbate hypertrophy, its role in inflammation and fibrosis is much less clear. Additional preclinical and clinical studies will be required to delineate testosterone's effect on the diabetic heart.

New Insights into Mechanisms Traditional Chinese Medicine for Allergic Rhinitis by Regulating Inflammatory and Oxidative Stress Pathways

Allergy rhinitis (AR) is becoming more common and has serious medical and societal consequences. Sneezing, paroxysmal nasal blockage, nasal itching, mucosal edema, coughing, and rhinorrhea are symptoms of this type I allergic immunological illness. Immunoglobulin E-mediated inflammation is the cause of it. Because AR is prone to recurrent attacks, extended medication therapy may impair its effectiveness. In addition to negatively affecting the patients' physical health, this can also negatively impact their mental health. During AR development, there are inflammatory and oxidative stress responses that are linked to problems in a number of signal transduction pathways. By using the terms "allergic rhinitis", "traditional Chinese medicine", "inflammation", and "oxidative stress", we screened for pertinent research published over the previous five years in databases like PubMed. We saw that NF-KB, TLR, IL-33/ST2, PI3K/AKT, MAPK, and Nrf2 are some of the most important inflammatory and oxidative stress pathways in AR. Studies have revealed that antioxidant and anti-inflammatory therapy reduced the risk of AR and was therapeutic; however, the impact of the therapy varies widely. The Chinese medical system places a high value on traditional Chinese medicine (TCM), which has been there for virtually all of China's 5000-year history. By influencing signaling pathways related to inflammation and oxidative stress, Chinese herbal medicine and its constituent compounds have been shown to prevent allergic rhinitis. This review will focus on this evidence and provide references for clinical treatment and scientific research applications.

The pathological and therapeutic roles of mesenchymal stem cells in preeclampsia

Mesenchymal stem cells (MSCs) have made progress in the treatment of ischemic and inflammatory diseases. Preeclampsia (PE) is characterized by placenta ischemic and inflammatory injury. Our paper summarized the new role of MSCs in PE pathology and its potency in PE therapy and analyzed its current limitations. Intravenously administered MSCs dominantly distributed in perinatal tissues. There may be additional advantages to using MSCs-based therapies for reproductive disorders. It will provide new ideas for future research in this field.

Beta-Carotene Affects the Effects of Heme Oxygenase-1 in Isolated, Ischemic/Reperfused Rat Hearts: Potential Role of the Iron

Beta-carotene (BC) is a well-known antioxidant. However, increasing evidence shows that under severe oxidative conditions, BC can become pro-oxidant, an effect that may be enhanced in the presence of iron (II). In our earlier studies, we observed that despite increasing heme oxygenase-1 (HO-1) levels in the heart, the protective effects of BC have been lost when it was used at a high concentration. Since iron releases from heme as a consequence of HO-1 activity, we hypothesized that the application of an iron-chelator (IC) would reverse the lost cardiac protection associated with an elevated HO-1 level. Thus, in the present study, we investigated the effects of desferrioxiamine (DFO) in isolated, ischemic/reperfused rat hearts after long-term treatment with vehicle or high-dose (HD) BC. Vehicle or 150 mg/bw kg daily doses of BC were administered to the rats for 4 weeks, and then their hearts were removed and subjected to 30 min of global ischemia (ISA) followed by 120 min of reperfusion (REP). During the experiments, cardiac function was registered, and at the end of the REP period, infarct size (IS) and HO-1 expression were measured. The results show that DFO treatment alone during REP significantly ameliorated postischemic cardiac function and decreased IS, although HO-1 expression was not increased significantly. In hearts isolated from BC-treated rats, no cardioprotective effects, despite an elevated HO-1 level, were observed, while DFO administration after ISA resulted in a mild improvement in heart function and IS. Our results suggest that iron could have a role whether BC exerts antioxidant or pro-oxidant effects in ISA/REP-injured hearts.

Macrophages Protect Endometriotic Cells Against Oxidative Damage Through a Cross-Talk Mechanism

This aim of this study was to investigate whether macrophages protect endometriotic cells from oxidative injury and to elucidate the underlying mechanisms of any protection. Endometriotic cells cultured with or without differentiated macrophages (dTHP-1 cells) were treated with hydrogen peroxide (H₂O₂) or methemoglobin, a major component of hemoglobin species in endometriotic cyst fluid. Co-culture experiments, microarray analysis, screening and validation of differentially expressed genes (DEGs), cell proliferation and viability assays, and experiments using a specific inhibitor were conducted to investigate the functional cross-talk between endometriotic cells and macrophages. Microarray analysis revealed that endometriotic cells co-cultured with dTHP-1 differentially express several genes compared with monoculture. Quantitative enzyme-linked immunosorbent assay (ELISA) and Western blotting analysis identified TGF-β1 as a promising candidate gene expressed in endometriotic cells co-cultured with dTHP-1 cells. TGF-β1 stimulated the expression of heme oxygenase-1 (HO-1) in dTHP-1 cells. HO-1 expression was increased in dTHP-1 cells co-cultured with endometriotic cells compared with the dTHP-1 monoculture. Both H₂O₂ and methemoglobin upregulated the expression of the HO-1 protein in the dTHP-1 monoculture; moreover, co-culture with endometriotic cells further enhanced HO-1 production. The co-culture with dTHP-1 protected endometriotic cells against oxidative injury. Blockade of HO-1 abolished the protective effects of macrophages. In an oxidative stress environment, TGF-β1 produced by endometriotic cells may protect against oxidative injury through the upregulation of macrophage-derived HO-1. The cross-talk between endometriotic cells and macrophages may contribute to the progression and pathogenesis of endometriosis.

HO-1 in Bone Biology: Potential Therapeutic Strategies for Osteoporosis

Osteoporosis is a prevalent bone disorder characterized by bone mass reduction and deterioration of bone microarchitecture leading to bone fragility and fracture risk. In recent decades, knowledge regarding the etiological mechanisms emphasizes that inflammation, oxidative stress and senescence of bone cells contribute to the development of osteoporosis. Studies have demonstrated that heme oxygenase 1 (HO-1), an inducible enzyme catalyzing heme degradation, exhibits anti-inflammatory, anti-oxidative stress and anti-apoptosis properties. Emerging evidence has revealed that HO-1 is critical in the maintenance of bone homeostasis, making HO-1 a potential target for osteoporosis treatment. In this Review, we aim to provide an introduction to current knowledge of HO-1 biology and its regulation, focusing specifically on its roles in bone homeostasis and osteoporosis. We also examine the potential of HO-1-based pharmacological therapeutics for osteoporosis and issues faced during clinical translation.

Adipose-derived mesenchymal stem cells protects renal function in a rat model of emphysema

BACKGROUND AND OBJECTIVE

The link between lung disease and kidney disorders has already been confirmed. Previous studies have documented that obstructive pulmonary disease is an independent predictor of decreased renal function, which reduces glomerular filtration rate. Recently, mesenchymal stem cells are the most important cell used in cell therapy. Accordingly, the present experiment was designed to evaluate the efficacy of adipose-derived mesenchymal stem cells (AMSCs) on improvement of renal function in elastase induced-pulmonary emphysema rats.

MATERIALS AND METHODS

Thirty male Sprague-Dawley rats divided into the 3 groups. Following intra-tracheal administration of elastase, the in vivo emphysema model established and confirmed according to the specific markers. Subsequently, systemic AMSCs injection was developed. the kidney injuries markers such as Blood urea nitrogen (BUN), creatinine, sodium and potassium as well as the kidney histopathologic parameters were assessed in all groups. Moreover, the oxidative stress markers levels including Malondialdehyde (MDA), Total antioxidant capacity (TAC), Catalase (CAT) and Glutathione peroxidase (GPx) were measured in kidney tissue and also inflammatory cytokines including IL-10, IL-6, and IFN-Ƴ were assessed in serum samples.

RESULTS

The marked rise in kidney injuries markers were observed which showed by enhancement of BUN and Creatinine levels in emphysema rats compared to the control. Furthermore, the results demonstrated increases in MDA levels and decreases in antioxidant activity which was in line with increases in inflammation cytokines in renal tissue. Conversely, AMSCs treatment improved renal function as shown by the decreases BUN, Creatinine and proteinuria. Furthermore, renal histological assay demonstrate improvement in glomerular and tubular damage and inflammatory cells accumulation.

CONCLUSIONS

Our results documented the promising kidney-protective properties of Adipose-Derived Mesenchymal Stem Cells in the kidney injuries induced by emphysema.

The non-canonical effects of heme oxygenase-1, a classical fighter against oxidative stress

The role of heme oxygenase-1 in resisting oxidative stress and cell protection has always been a hot research topic. With the continuous deepening of research, in addition to directly regulating redox by catalyzing the degradation of heme, HO-1 protein also participates in the gene expression level in a great diversity of methods, thereby initiating cell defense. Particularly the non-canonical nuclear-localized HO-1 and HO-1 protein interactions play the role of a warrior against oxidative stress. Besides, HO-1 may be a promising marker for disease prediction and detection in many clinical trials. Especially for malignant diseases, there may be new advances in the treatment of HO-1 by regulating abnormal ROS and metabolic signaling. The purpose of this review is to systematically sort out and describe several aspects of research to facilitate further detailed mechanism research and clinical application promotion in the future.

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The different subcellular localizations ofHO-1 implies that it has special functions.

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Nuclear HO-1 plays an indispensable role in gene regulation and other aspects.

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The interactions between HO-1 and others provide the possibility to participate in vital physiological processes.

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HO-1 may become a potential disease assessment marker.

HO-1 nuclear accumulation and interaction with NPM1 protect against stress-induced endothelial senescence independent of its enzymatic activity

Heme oxygenase-1 (HO-1) has attracted accumulating attention for its antioxidant enzymatic activity. However, the exact regulatory role of its non-enzymatic activity in the cardiovascular system remains unaddressed. Here, we show that HO-1 was accumulated in the nuclei of stress-induced senescent endothelial cells, and conferred protection against endothelial senescence independent of its enzymatic activity. Overexpression of ΔHO-1, a truncated HO-1 without transmembrane segment (TMS), inhibited H2O2-induced endothelial senescence. Overexpression of ΔHO-1H25A, the catalytically inactive form of ΔHO-1, also exhibited anti-senescent effect. In addition, infection of recombinant adenovirus encoding ΔHO-1 with three nuclear localization sequences (NLS), alleviated endothelial senescence induced by knockdown of endogenous HO-1 by CRISPR/Cas9. Moreover, repression of HO-1 nuclear translocation by silencing of signal peptide peptidase (SPP), which is responsible for enzymatic cleavage of the TMS of HO-1, exacerbated endothelial senescence. Mechanistically, nuclear HO-1 interacted with NPM1 N-terminal portion, prevented NPM1 translocation from nucleolus to nucleoplasm, thus disrupted NPM1/p53/MDM2 interactions and inhibited p53 activation by NPM1, finally resisted endothelial senescence. This study provides a novel understanding of HO-1 as a promising therapeutic strategy for vascular senescence-related cardiovascular diseases.

Effect of whole-body resistance training at different load intensities on circulating inflammatory biomarkers, body fat, muscular strength, and physical performance in postmenopausal women

The primary purpose of this study was to identify the impact of whole-body resistance training (RT) at different load intensities on adipokines, adhesion molecules, and extracellular heat shock proteins in postmenopausal women. As secondary purpose, we analyzed the impact of RT at different load intensities on body fat, muscular strength, and physical performance. Forty participants were randomized into lower-load intensity RT (LIRT, n = 20, 30-35 repetition maximum in the first set of each exercise) or higher-load intensity RT (HIRT, n = 20, 8-12 repetition maximum in the first set of each exercise). Adipokines (adiponectin and leptin), adhesion molecules (MCP-1 and ICAM-1), extracellular heat shock proteins (HO-1 and eHSP60), body fat, muscular strength (1RM), and physical performance [400-meter walking test (400-M) and 6-minute walking test (6MWT)] were analyzed at baseline and after 12-weeks RT. There was a significant time-by-group interaction for eHSP60 (P = 0.049) and 400-M (P = 0.003), indicating superiority of HIRT (d = 0.47 and 0.55). However, both groups similarly improved adiponectin, ICAM-1, HO-1, body fat, 1RM, and 6MWT (P < 0.05). Our study suggests that load intensity does not seem to determine the RT effect on several obesity-related pro-inflammatory and chemotactic compounds, body fat, 1RM, and 6MWT in postmenopausal women, although a greater improvement has been revealed for eHSP60 and 400-M in HIRT. Novelty: Higher-load intensity resistance training improves eHSP60 and 400-M in postmenopausal women. Resistance training improves the inflammatory profile, body fat, muscle strength, and 6MWT, regardless of load intensity.

Phenylethanoid Glycosides From Callicarpa kwangtungensis Chun Attenuate TNF-α-Induced Cell Damage by Inhibiting NF-κB Pathway and Enhancing Nrf2 Pathway in A549 Cells

Background: Acute lung injury (ALI) is a complicated and severe lung disease, which is often characterized by acute inflammation. Poliumoside (POL), acteoside (ACT) and forsythiaside B (FTB) are phenylethanoid glycosides (PGs) with strong antioxidant, anti-inflammatory, and anti-apoptotic properties, which are extracted from Callicarpa kwangtungensis Chun (CK). The aim of this study was to investigate the protective effects of POL, ACT, and FTB against TNF-α-induced damage using an ALI cell model and explore their potential mechanisms.

Methods and Results: MTT method was used to measure cell viability. Flow cytometry was used for detecting the apoptosis rate. Reactive oxygen species (ROS) activity was determined using fluorescence microscope. The expression of mRNA in apoptosis-related genes (Caspase 3, Caspase 8, and Caspase 9) were tested by qPCR. The effects of POL, ACT, FTB on the activities of nuclear factor erythroid-2 related factor 2 (Nrf2), nuclear factor kappa-B (NF-κB) and the expression of their downstream genes were assessed by western blotting and RT-PCR in A549 cells. In the current study, POL, ACT, and FTB dose-dependently attenuated TNF-α-induced IL-1β, IL-6 and IL-8 production, cell apoptosis, the expression of apoptosis-related genes (Caspase 3, Caspase 8, and Caspase 9) and ROS activity. POL, ACT, and FTB not only increased in the mRNA levels of antioxidative enzymes NADPH quinone oxidoreductase (NQO1), glutamate cysteine ligase catalytic subunit (GCLC), heme oxygenase (HO-1), but also decreased the mRNA levels of IL-1β, IL-6 and IL-8. Furthermore, they upregulated the expression of Keap1 and enhanced the activation of Nrf2, while decreased the expression of phosphor-IκBα (p-IκBα) and nuclear p65. In addition, no significant changes were observed in anti-inflammatory and antioxidant effects of POL, ACT, FTB following Nrf2 and NF-κB p65 knockdown.

Conclusion: Our study revealed that POL, ACT, and FTB alleviated oxidative damage and lung inflammation of TNF-α-induced ALI cell model through regulating the Nrf2 and NF-κB pathways.

Potential protective roles of curcumin against cadmium-induced toxicity and oxidative stress

Curcumin, used as a spice and traditional medicine in India, exerts beneficial effects against several diseases, owing to its antioxidant, analgesic, and anti-inflammatory properties. Evidence indicates that curcumin might protect against heavy metal-induced organ toxicity by targeting biological pathways involved in anti-oxidation, anti-inflammation, and anti-tumorigenesis. Curcumin has received considerable attention owing to its therapeutic properties, and the mechanisms underlying some of its actions have been recently investigated. Cadmium (Cd) is a heavy metal found in the environment and used extensively in industries. Chronic Cd exposure induces damage to bones, liver, kidneys, lungs, testes, and the immune and cardiovascular systems. Because of its long half-life, exposure to even low Cd levels might be harmful. Cd-induced toxicity involves the overproduction of reactive oxygen species (ROS), resulting in oxidative stress and damage to essential biomolecules. Dietary antioxidants, such as chelating agents, display the potential to reduce Cd accumulation and metal-induced toxicity. Curcumin scavenges ROS and inhibits oxidative damage, thus resulting in many therapeutic properties. This review aims to address the effectiveness of curcumin against Cd-induced organ toxicity and presents evidence supporting the use of curcumin as a protective antioxidant.

Low Dose of β-Carotene Regulates Inflammation, Reduces Caspase Signaling, and Correlates with Autophagy Activation in Cardiomyoblast Cell Lines

Background

Excessive reactive oxygen species (ROS) stimulate mitochondrial damage that causes degenerative diseases such as cardiovascular disease (CVD). β-carotene (BC), a natural antioxidant able to counteract free radicals, acts as a cytoprotective agent. However, knowledge of the role of BC on cardiomyoblasts is limited. In this study, we explored its role on COX4, Tom20, Nfr1, Nrf2, Nf-κB, LC3, p62, caspase 3, and caspase 9 and its association with cardiomyoblast viability and survival.

Material/Methods

H9C2 cell lines were seeded, cultivated until 90% to 100% confluency, and treated with various doses of BC: 10 μM, 1 μM, 0.1 μM, and 0.01 μM. After 24 h, the cells were harvested, lyzed, and tested for specific related protein expressions from each dose.

Results

Low-dose BC induced autophagy most effectively at 1 μM, 0.1 μM, and 0.01 μM, as indicated by a decrease of LC3II and p62 levels. We observed that Nf-κB protein levels were suppressed; Nrf2 was stimulated, but Nrf1 was not altered significantly. Further, low-dose BC might stimulate cell viability by reducing apoptotic signals of caspase 3 and 9. Notably, low-dose BC also showed potential to increase Tom20 protein levels.

Conclusions

Low-dose BC supplementation shows beneficial effects, especially at 0.01 μM, by reducing inflammation through the suppression of Nf-κB and increase of Nrf2 level. Autophagy as a cellular maintenance mechanism was also stimulated, and the amount of the mitochondria marker Tom20 increased. Taken together, results showed that specific low-dose BC is effective and might improve cell viability by stimulating autophagy, inhibiting proinflammatory factors, and suppressing apoptosis.

Heme Degradation in Pathophysiology of and Countermeasures to Inflammation-Associated Disease

The class of tetrapyrrol "coordination complexes" called hemes are prosthetic group components of metalloproteins including hemoglobin, which provide functionality to these physiologically essential macromolecules by reversibly binding diatomic gasses, notably O₂, which complexes to ferrous (reduced/Fe(II)) iron within the heme porphyrin ring of hemoglobin in a pH- and PCO₂-dependent manner-thus allowing their transport and delivery to anatomic sites of their function. Here, pathologies associated with aberrant heme degradation are explored in the context of their underlying mechanisms and emerging medical countermeasures developed using heme oxygenase (HO), its major degradative enzyme and bioactive metabolites produced by HO activity. Tissue deposits of heme accumulate as a result of the removal of senescent or damaged erythrocytes from circulation by splenic macrophages, which destroy the cells and internal proteins, including hemoglobin, leaving free heme to accumulate, posing a significant toxicogenic challenge. In humans, HO uses NADPH as a reducing agent, along with molecular oxygen, to degrade heme into carbon monoxide (CO), free ferrous iron (FeII), which is sequestered by ferritin protein, and biliverdin, subsequently metabolized to bilirubin, a potent inhibitor of oxidative stress-mediated tissue damage. CO acts as a cellular messenger and augments vasodilation. Nevertheless, disease- or trauma-associated oxidative stressors sufficiently intense to overwhelm HO may trigger or exacerbate a wide range of diseases, including cardiovascular and neurologic syndromes. Here, strategies are described for counteracting the effects of aberrant heme degradation, with a particular focus on "bioflavonoids" as HO inducers, shown to cause amelioration of severe inflammatory diseases.

Selenium Yeast Alleviates Ochratoxin A-Induced Apoptosis and Oxidative Stress via Modulation of the PI3K/AKT and Nrf2/Keap1 Signaling Pathways in the Kidneys of Chickens

The purpose of this study was to investigate the protective effect and mechanism of yeast selenium (Se-Y) on ochratoxin- (OTA-) induced nephrotoxicity of chickens. A total of 80 one-day-old healthy chickens were randomly divided into 4 equal groups: control, OTA (50 μg/kg OTA), Se-Y (0.4 mg/kg Se-Y), and OTA+Se-Y (50 μg/kg OTA+0.4 mg/kg Se-Y). In the OTA chickens, differences in body weight, kidney coefficient, biochemical histological analysis, antioxidant capability, and the expression levels of the PI3K/AKT and Nrf2/Keap1 signaling pathway-related genes were observed. The levels of total superoxide dismutase (T-SOD), antioxidant capacity (T-AOC), catalase (CAT), and glutathione (T-GSH) significantly decreased, but the malondialdehyde (MDA) level of the kidneys significantly increased in the OTA treatment group. More importantly, treatment with Se-Y improved the antioxidant enzyme activities within the kidneys of chickens exposed to OTA. In addition, administration of OTA resulted in apoptosis and was associated with decreased expression of AKT, PI3K, and Bcl-2, which in turn enhanced expression of Caspase3, Bax, and P53. However, Se-Y improved the antioxidant defense system through activation of the Nrf2/Keap1 signaling pathway. Gene expression of Nrf2 and its target genes (HO-1, GSH-px, GLRX2, MnSOD, and CAT) was downregulated following OTA exposure. Conversely, Se-Y treatment resulted in a significant upregulation of the same genes. Besides, significant downregulations of protein expression of HO-1, CAT, MnSOD, Nrf2, and Bcl-2 and a significant upregulation of Caspase3 and Bax levels were observed after contaminated with OTA. Notably, OTA-induced apoptosis and oxidative damage in the kidney of chickens were reverted back to normal level in the OTA+Se-Y group. Taken together, the data suggest that Se-Y alleviates OTA-induced nephrotoxicity in chickens, possibly through the activation of the PI3K/AKT and Nrf2/Keap1 signaling pathways.

Induction of HO-1 by Mevastatin Mediated via a Nox/ROS-Dependent c-Src/PDGFRα/PI3K/Akt/Nrf2/ARE Cascade Suppresses TNF-α-Induced Lung Inflammation

Background: Mevastatin (MVS), a 3-hydroxy-3-methylglutaryl coenzyme, a reductase (HMG-CoA) inhibitor, has anti-inflammatory effects potentially via up-regulation of heme oxygenase-1 (HO-1). However, the mechanisms underlying MVS-induced HO-1 expression remain largely unknown in human pulmonary alveolar epithelial cells (HPAEpiCs). Methods: HO-1 and intercellular adhesion molecule (ICAM)-1 expression were determined using real-time PCR, Western blotting, and promoter reporter analyses. The signaling components were investigated using pharmacological inhibitors or specific small interfering RNA (siRNA)s. Interaction between Nrf2 and the antioxidant response element (ARE) binding site for the HO-1 promoter was determined by chromatin immunoprecipitation (ChIP) assay. Results: Upregulation of HO-1 by MVS attenuated the tumor necrosis factor (TNF)-α-stimulated ICAM-1 expression associated with THP-1 adhesion to HPAEpiCs. These inhibitory effects of HO-1 were reversed by tin protoporphyrin (SnPP)IX or by transfection with HO-1 siRNA. MVS-induced HO-1 expression was mediated via NADPH oxidase (Nox)-derived reactive oxygen species (ROS) generation. Activation of Nox2/ROS further stimulated the phosphorylation of p47^phox, proto-oncogene tyrosine-protein kinase (c-Src), platelet-derived growth factor receptor (PDFGR)α, protein kinase B (Akt), and Nrf2, which were inhibited by siRNAs. Pretreatment with pharmacological inhibitors, including diphenyleneiodonium (DPI), apocynin (APO), N-acetyl-L-cysteine (NAC), PP1, AG1296, or LY294002, reduced the MVS-activated Nrf2 nuclear-translocation binding to the ARE on the HO-1 promoter. Conclusions: MVS-induced HO-1 is, at least in part, mediated through a p47^phox/Nox2/ROS-dependent activation of c-Src/PDGFRα/PI3K/Akt-regulated Nrf2/ARE axis and suppresses the TNF-α-mediated inflammatory responses in HPAEpiCs.

The Nrf2/HO-1 Axis as Targets for Flavanones: Neuroprotection by Pinocembrin, Naringenin, and Eriodictyol

Flavanones are a group of flavonoids that derive from their immediate chalcone precursors through the action of chalcone isomerase enzymes. The Aromatic A and B rings, C4-keto group, and the 15-carbon flavonoid skeleton are all evident in flavanones, but a notable absence of C2-C3 double bond and a lack of oxygenation at C-3 position of the C-ring makes them distinctively different from other groups such as flavonols (e.g., quercetin). On the basis of oxygenation level in the B ring, flavanones can vary from each other as exemplified by pinocembrin (no oxygenation), naringenin (4′-hydroxyl), or eriodictyol (3′,4′-dihydroxyl substitution). These groups are generally weaker free radical scavengers as compared to quercetin and derivatives though eriodictyol has a better free radical scavenging profile within the group due to the presence of the catechol functional moiety. In this communication, their antioxidant potential through the induction of antioxidant defenses is scrutinized. These compounds as exemplified by pinocembrin could induce the nuclear factor erythroid 2-related factor 2- (Nrf2-) heme oxygenase-1 (HO-1) axis leading to amelioration of oxidative stress in cellular and animal models. Their neuroprotective effect through such mechanism is discussed.

Spotlight on a New Heme Oxygenase Pathway: Testosterone-Induced Shifts in Cardiac Oxidant/Antioxidant Status

A low testosterone level contributes to the development of oxidative damages; however, the cardiovascular effects of exogenous hormone therapy are not well elucidated. The aim of our work is to study the association of the testosterone level, antioxidant/oxidant system, and anti-inflammatory status related to the heme oxygenase (HO) system. To determine the effects of testosterone, 10-week-old, and 24-month-old sham-operated and castrated male Wistar rats were used. One part of the castrated animals was daily treated with 2.5 mg/kg cyproterone acetate, while the hormone replacement therapy was performed via an i.m. injection of a dose of 8.0 mg testosterone undecanoate/kg/once a week. The plasma testosterone level, the activity of HO and myeloperoxidase (MPO) enzymes; the concentrations of the HO-1, tumor necrosis alpha (TNF-α), and cyclic guanosine monophosphate (cGMP), as well as the total level of glutathione (GSH + GSSG) were determined from the cardiac left ventricle. In accordance with the testosterone values, the aging process and castration resulted in a decrease in antioxidant HO activity, HO-1 and cGMP concentrations and in the level of GSH + GSSG, whereas the inflammatory TNF-α and MPO activity significantly increased. Testosterone therapy was able to restore the physiological values. Our results clearly show that testosterone replacement therapy increases the antioxidant status and mitigates the inflammatory parameters via the modulation of the HO system.

Grape Seed Proanthocyanidin Extract Alleviates AflatoxinB₁-Induced Immunotoxicity and Oxidative Stress via Modulation of NF-κB and Nrf2 Signaling Pathways in Broilers

Aflatoxin B₁ (AFB₁) is a widely spread mycotoxin contaminates food and feed, causing severe oxidative stress damages and immunotoxicity. Grape seed proanthocyanidin (GSPE), a natural antioxidant with wide range of pharmacological and medicinal properties. The goal of the present study was to investigate the protective effects of GSPE against AFB₁-induced immunotoxicity and oxidative stress via NF-κB and Nrf2 signaling pathways in broiler chickens. For the experiment, 240 one-day old Cobb chicks were allocated into four dietary treatment groups of six replicates (10 birds per replicate): 1. Basal diet (control); 2. Basal diet + AFB₁ 1mg/kg contaminated corn (AFB₁); 3. Basal diet + GSPE 250 mg/kg (GSPE); 4. Basal diet + AFB₁ 1 mg/kg + GSPE 250 mg/kg (AFB₁ + GSPE). The results showed that GSPE significantly decreased serum inflammatory cytokines TNF-α, IFN-γ, IL-1β, IL-10, and IL-6 induced by AFB₁. Similarly, GSPE + AFB₁ treated group revealed a significant decrease in mRNA expressions of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β, and IL-6) in the splenic tissue compared to the AFB₁ treatment group. In addition, western blotting results manifested that GSPE treatment normalized the phosphorylation of nuclear factor kappa B (p65) and the degradation of IκBα protein induced by AFB₁. Furthermore, GSPE enhanced the antioxidant defense system through activating the nuclear factor-erythroid-2-related factor (Nrf2) signaling pathway. The mRNA and protein expression level of Nrf2 and its down streaming associated genes were noted up-regulated by the addition of GSPE, and down-regulated in the AFB₁ group. Taken together, GSPE alleviates AFB₁-induced immunotoxicity and oxidative damage by inhibiting the NF-κB and activating the Nrf2 signaling pathways in broiler chickens. Conclusively, our results suggest that GSPE could be considered as a potential natural agent for the prevention of AFB₁-induced immunotoxicity and oxidative damage.

Postconditioning-like effect of exercis: new paradigm in experimental menopause

The progression of coronary artery diseases in premenopausal women is lower than in age-matched men; however, its probability increases rapidly after menopause. The aim of our study was to investigate the postconditioning-like effects of voluntary physical exercise on postmenopausal cardiovascular outcomes after myocardial infarction. We used fertile Wistar females [control (CTRL)] and pharmacologically induced estrogen-deficient (POVX; 750 µg/kg triptorelin im, every 4th week) rats. CTRL and POVX animals were randomly assigned to receive an injection of 0.1 mg isoproterenol (ISO)/kg. At the 20th hour after ISO injection, serum markers of myocardial injury, such as lactate dehydrogenase (LDH) and myoglobin, were measured. After a 3-wk resting period, ISO-treated and untreated animals were further divided into subgroups on the basis of 6 wk of physical exercise. At the end of the experiment, cardiac activity and content of the antioxidative heme oxygenase (HO) enzyme, levels of GSH and GSH + GSSG, activity of myeloperoxidase, as well as the concentration of TNF-α were determined. At the end of the experimental period, we observed a significant decrease in the activity and content of HO enzymes in POVX and POVX/ISO rats, whereas physical exercise significantly improved HO and GSH values in both CTRL and POVX rats. Furthermore, our training protocol significantly reduced the pathological levels of myeloperoxidase and TNF-α. Our findings clearly demonstrate that modulation of the HO system by voluntary physical exercise is a key process to decrease inflammatory parameters and ameliorate the antioxidative status in estrogen-deficient conditions postmyocardial injury. NEW & NOTEWORTHY We used a noninvasive rat model of estrogen deficiency and myocardial infarction. The long-term effects of isoproterenol treatment revealed reduced heme oxygenase enzyme activity and expression and decreased glutathione levels. Isoproterenol treatment enhanced the myeloperoxidase enzyme activity. Voluntary physical exercise ameliorated the antioxidative status by increasing of the heme oxygenase enzyme system. Voluntary physical exercise is a potential therapeutic tool to improve cardiac antioxidant status in menopausal women postmyocardial injury.

Gastrodin induced HO-1 and Nrf2 up-regulation to alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells through p38 MAPK phosphorylation

Nuclear factor erythroid-related factor 2 (Nrf2) has been implicated in several detoxifying and antioxidant defense processes. Nrf2-mediated heme oxygenase-1 (HO-1) expression was demonstrated to play a key role against oxidative stress. Gastrodin (GSTD) is a well-known active compound isolated from the roots of Rhizoma gastrodiae, a plant used in ancient Chinese traditional medicine. The aim of this work was to investigate whether GSTD could alleviate H₂O₂-induced oxidative stress in mouse liver sinusoidal endothelial cells (LSECs). In LSECs exposed to 1 mM H₂O₂, treatment with GSTD (1, 10, or 50 µM) resulted in higher cell viability than the untreated control. Treated cells maintained a higher Bcl2/Bax ratio and suppressed caspase-9 expression compared with untreated cells, reducing cell apoptosis. GSTD was protective for H₂O₂-induced oxidative injury by reducing the generation of intracellular reactive oxygen species and malondialdehyde. HO-1 and Nrf2 expressions were synergistically upregulated by GSTD. Inhibition of HO-1 by 10 µM zinc protoporphyrin resulted in less protective effects on cell viability and malondialdehyde reduction by GSTD treatment in H₂O₂-exposed LSECs. Additionally, phosphorylated p38 in LSECs exposed to H₂O₂ was elevated by GSTD. Inhibition of p38 phosphorylation by SB203580 did not induce Nrf2 and HO-1 expression after 1 or 10 µM GSTD treatment and the protective effect on cell viability and malondialdehyde reduction in H₂O₂-exposed LSECs was reduced. The data conclusively demonstrated that GSTD-induced HO-1 and Nrf2 expression is involved in protection of LSECs from H₂O₂-induced oxidative injury, which may be regulated by p38 phosphorylation.

The Nrf2 Signaling in Retinal Ganglion Cells under Oxidative Stress in Ocular Neurodegenerative Diseases

Retinal ganglion cells (RGCs) are one of the important cell types affected in many ocular neurodegenerative diseases. Oxidative stress is considered to be involved in retinal RGCs death in ocular neurodegenerative diseases. More and more attention has been focused on studying the agents that may have neuroprotective effects. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a key nuclear transcription factor for the systemic antioxidant defense system. This review elucidates the underlying mechanism of the Nrf2-mediated neuroprotective effects on RGCs in ocular neurodegenerative diseases, such as diabetic retinopathy and retinal ischemia-reperfusion injury. Several Nrf2 inducers that shield RGCs from oxidative stress-induced neurodegeneration via regulating Nrf2 signaling are discussed.

Inhibition of miR-92a Suppresses Oxidative Stress and Improves Endothelial Function by Upregulating Heme Oxygenase-1 in db/db Mice

AIMS

Inhibition of microRNA-92a (miR-92a) is reported to suppress endothelial inflammation and delay atherogenesis. We hypothesize that miR-92a inhibition protects endothelial function through suppressing oxidative stress in diabetic db/db mice.

RESULTS

In this study, we found elevated expression of miR-92a in aortic endothelium from db/db mice and in renal arteries from diabetic subjects. Endothelial cells (ECs) exposed to advanced glycation end products (AGEs) and oxidized low-density lipoprotein express higher level of miR-92a. Overexpression of miR-92a impairs endothelium-dependent relaxations (EDRs) in C57BL/6 mouse aortas. Overexpression of miR-92a suppresses expression of heme oxygenase-1 (HO-1), a critical cytoprotective enzyme, whereas inhibition of miR-92a increases HO-1 expression in human umbilical vein ECs (HUVECs) and db/db mouse aortas. Importantly, miR-92a inhibition by Ad-anti-miR-92a improved EDRs and reduced reactive oxygen species (ROS) production in db/db mouse aortas. HO-1 inhibition by SnMP or HO-1 knockdown by shHO-1 reversed the suppressive effect of miR-92a inhibition on ROS production induced by AGE treatment in C57BL/6 mouse aortas. In addition, SnMP reversed miR-92a inhibition-induced improvement of EDRs in AGE-treated C57BL/6 mouse aortas and in db/db mouse aortas.

INNOVATION

Expression of miR-92a is increased in diabetic aortic endothelium and inhibition of miR-92a exerts vasoprotective effect in diabetic mice through HO-1 upregulation in ECs.

CONCLUSION

MiR-92a expression is elevated in diabetic ECs. MiR-92a overexpression impairs endothelial function and suppresses HO-1 expression in ECs. Inhibition of miR-92a attenuates oxidative stress and improves endothelial function through enhancing HO-1 expression and activity in db/db mouse aortas. Antioxid. Redox Signal. 28, 358-370.

Heme Oxygenase-1 Activity as a Correlate to Exercise-Mediated Amelioration of Cognitive Decline and Neuropathological Alterations in an Aging Rat Model of Dementia

Alzheimer's disease (AD) is a neurodegenerative disorder with cognitive impairment. Physical exercise has long been proven to be beneficial in the disorder. The present study was designed to examine the effect of voluntary exercise on spatial memory, imaging, and pathological abnormalities. Particular focus has been given to the role of heme oxygenase-1 (HO-1)—an important cellular cytoprotectant in preserving mental acuity—using an aging rat model of dementia. Male and female Wistar rats were segregated into six groups—namely, (i) aged sedentary (control) females (ASF, n = 8); (ii) aged sedentary (control) males (ASM, n = 8); (iii) aged running females (ARF, n = 8); (iv) aged running males (ARM, n = 8); (v) young control females (YCF, n = 8); and (vi) young control males (YCM, n = 8). Rats in the ARF and ARM groups had free access to a standardized inbuilt running wheel during the 3-month evaluation period. Spatial memory was investigated using the Morris Water Test, imaging and pathological alterations were assessed using positron emission tomography (PET) imaging and histopathological examinations (H&E, Congo red staining), respectively, and HO-1 enzyme activity assays were also conducted. The outcomes suggest that voluntary physical exercise mitigates impaired spatial memory and neuropathological changes exhibited by the aging sedentary group, via elevated HO-1 activity, contributing to the antioxidant capacity in the aging brain.

Endothelin-1-induced hypertrophic alterations and heme oxygenase-1 expression in cardiomyoblasts are counteracted by beta estradiol: in vitro and in vivo studies

Endothelin-1 (ET-1), a potent vasoconstrictor normally active in maintaining vascular tone, may mediate significant pathogenic effects, contributing to several serious diseases when aberrantly expressed or regulated. The present study evaluates the capacity of ET-1 to affect endothelin-1-associated hypertrophic activity and decreased expression of heme oxygenase-1 by H9c2 rat cardiomyoblasts in vitro, corresponding to in vivo processes underlying cardiovascular diseases (CVDs). Beta estradiol (β-E) is tested for its capacity to alter the effects of ET-1. H9c2 cells, cultured 48 h, were stimulated with 100-10,000 nM of ET-1 and evaluated for changes in cell size, cell viability, and expression of the cytoprotective heat shock protein heme oxygenase-1 (HO-1), with 200 nM of β-E included in selected cultures to evaluate its effect on ET-1-mediated changes. The application of 100 to 10,000 nM of ET-1 resulted in a significant increase in average cell size and decreases in both cell viability and HO-1 protein content (p < 0.05). Moreover, 200 nM of β-E was observed to significantly counteract these effects by cardiomyoblasts stimulated with 1000 nM of ET-1 (p < 0.05). Sprague-Dawley rats treated intravenously with 1000 ng/kg of ET-1 demonstrated reduced HO-1 expression in peripheral blood and left ventricular tissue, which was counteracted by injection of 200 ng/kg β-E-demonstrating a possible correspondence between in vitro and in vivo effects. An outcome of particular value for clinical use of β-E, in the management of cardiac hypertrophy, is the observed capacity of the drug to abate ET-1-mediated suppression of HO-1 expression. It has been previously demonstrated that HO-1 inducers exhibit potent cardioprotective properties, thus offering the promise of combining them with β-E, allowing lower effective dosage of the drug and concomitantly lower adverse side effects associated with its clinical use. Major findings of this investigation are that pretreatment of cardiomyoblasts with β-E inhibited their hypertrophic response to ET-1 and counteracts the decrease of cell viability. These effects were associated with a restoration of HO-1 protein expression in both under in vitro and in vivo conditions.

Alpha-Melanocyte-stimulating Hormone Induces Vasodilation and Exerts Cardioprotection Through the Heme-Oxygenase Pathway in Rat Hearts

Alpha–melanocyte-stimulating hormone (α-MSH) is a protein with known capacity for protection against cardiovascular ischemia–reperfusion (I/R) injury. This investigation evaluates the capacity of α-MSH to mitigate I/R effects in an isolated working rat heart model and determine the dependency of these alterations on the activity of heme oxygenase-1 (HO-1, hsp-32), a heat shock protein that functions as a major antioxidant defense molecule. Healthy male Sprague Dawley rats were used for all experiments. After treatment with selected doses of α-MSH, echocardiographic examinations were performed on live, anesthetized animals. Hearts were harvested from anesthetized rats pretreated with α-MSH and/or the HO-1 inhibitor SnPP, followed by cardiac function assessment on isolated working hearts, which were prepared using the Langendorff protocol. Induction of global ischemia was performed, followed by during reperfusion assessment of cardiac functions. Determination of incidence of cardiac arrhythmias was made by electrocardiogram. Major outcomes include echocardiographic data, suggesting that α-MSH has mild effects on systolic parameters, along with potent antiarrhythmic effects. Of particular significance was the specificity of dilatative effects on coronary vasculature, and similar outcomes of aortic ring experiments, which potentially allow different doses of the compound to be used to selectively target various portions of the vasculature for dilation.

Role of Heme Oxygenases in Cardiovascular Syndromes and Co-morbidities

Cardiovascular Diseases (CVD), are the leading cause of human mortality worldwide and the focus of the intensive investigation is to characterize their pathogenesis. This review examines contribution to CVD of heme oxygenases (HOs), heat shock protein enzymes, comprising 3 isoforms: HO-1 (inducible), HO-2 (constitutively expressed) and HO-3 (function presently undefined), which constitute a primary endogenous countermeasure to oxidative tissue damage. Their role as CVD countermeasures is considered in the context of atherosclerosis, consequences of which are the leading cause of CVD deaths and from which 5 major syndromes may develop, namely: coronary artery disease and stroke, peripheral artery disease, kidney disease, cardiopulmonary disease and cerebrovascular disease. Over 75% of CVD deaths result from Coronary artery disease and stroke, with the severity of these conditions correlating with a systemic increase of the endogenous antioxidant bilirubin, produced by HO degradation of heme. Peripheral artery disease, (PAD) resulting from constricted arteries of the extremities is a painful and disabling condition, the severity of which correlates with elevated serum HO. Whether this represents an adaptive response or the enzyme is a contributor to PAD, remains to be determined. CVD symptoms, particularly hypertension, damage the vasculature and filtering structures of the kidneys and may be ameliorated by HO inducers. Interestingly, constitutive renal expression of HO-2 indicates that the enzyme is vital for healthy kidney function. Right ventricular hypertrophy and increased vascular resistance in blood vessels of the lungs exhibit mutually reinforcing positive feedback to result in cardiopulmonary heart disease, with morbidity and mortality resulting from associated inflammation and may be decreased with HO-1 inducers. Cerebrovascular disease, a major CVD complication affecting brain vasculature, with resulting susceptibility to stroke, maybe potently ameliorated by HO-1 inducers. Conclusion: Each of the six major categories of CVD exhibit features of pathogenesis that hold potential as future therapeutic targets, for modulated heme oxygenase activity.

Heme Oxygenase-1: Clinical Relevance in Ischemic Stroke

Stroke is the second-leading cause of death and a leading cause of serious long-term disability worldwide, with an increasing global burden due to the growing and aging population. However, strict eligibility criteria for current treatment opportunities make novel therapeutic approaches desirable. Oxidative stress plays a pivotal role during cerebral ischemia, eventually leading to neuronal injury and cell death. The significant correlation between redox imbalance and ischemic stroke has led to various treatment strategies targeting the endogenous antioxidant system in order to ameliorate the adverse prognosis in patients with cerebral infarction. One of the most extensively investigated cellular defense pathway in this regard is the Nrf2-heme oxygenase-1 (HO-1) axis. In this review, our aim is to focus on the potential clinical relevance of targeting the HO-1 pathway in ischemic stroke.

Neurodevelopment at Age 10 Years of Children Born <28 Weeks With Fetal Growth Restriction

OBJECTIVES

We sought to evaluate the relationships between fetal growth restriction (FGR) (both severe and less severe) and assessments of cognitive, academic, and adaptive behavior brain function at age 10 years.

METHODS

At age 10 years, the Extremely Low Gestational Age Newborns Cohort Study assessed the cognitive function, academic achievement, social-communicative function, psychiatric symptoms, and overall quality of life of 889 children born before 28 weeks' gestation. A pediatric epileptologist also interviewed parents as part of a seizure evaluation. The 52 children whose birth weight z scores were <-2 were classified as having severe FGR, and the 113 whose birth weight z scores were between -2 and -1 were considered to have less severe FGR.

RESULTS

The more severe the growth restriction in utero, the lower the level of function on multiple cognitive and academic achievement assessments performed at age 10 years. Growth-restricted children were also more likely than their extremely preterm peers to have social awareness impairments, autistic mannerisms, autism spectrum diagnoses, difficulty with semantics and speech coherence, and diminished social and psychosocial functioning. They also more frequently had phobias, obsessions, and compulsions (according to teacher, but not parent, report).

CONCLUSIONS

Among children born extremely preterm, those with severe FGR appear to be at increased risk of multiple cognitive and behavioral dysfunctions at age 10 years, raising the possibility that whatever adversely affected their intrauterine growth also adversely affected multiple domains of cognitive and neurobehavioral development.

Protective Effect of Prunus Cerasus (Sour Cherry) Seed Extract on the Recovery of Ischemia/Reperfusion-Induced Retinal Damage in Zucker Diabetic Fatty Rat

Among diabetes patients, ophthalmological complications are very frequent. High blood glucose and (consequential) ischemia-reperfusion (I/R) injury contribute significantly to the severity of retinopathies. Diabetic retinopathy is among the leading causes of blindness. Our study demonstrates the effect of sour cherry seed extract (SCSE) on blood glucose and function of the retina with electroretinography (ERG) in a diabetic setting with or without ischemia-reperfusion (I/R) injury in Zucker Diabetic Fatty (ZDF) rats. Our results prove that the SCSE has a retinoprotective effect in diabetic rats: according to ERG measurements, SCSE treatment mitigated the retinal function-damaging effect of diabetes, and proved to be protective in the diabetic eye against ischemia-reperfusion injuries of the retina. Outcomes suggest that the protective effects of SCSE may occur through several pathways, including HO-1 dependent mechanisms. The observation that SCSE treatment decreases blood glucose is also novel. These findings offer the possibility for development of novel therapeutic strategies utilizing this emerging functional food, in particular in the prevention of conditions resulting from high blood glucose or I/R injury, such as deterioration of retinal microcirculation.

Cadmium-induced toxicity is rescued by curcumin: A review

Cadmium (Cd) is one of the most common environmental and occupational heavy metals with extended distribution. Exposure to Cd may be associated with several deleterious consequences on the liver, bones, kidneys, lungs, testes, brain, immunological, and cardiovascular systems. Overproduction of reactive oxygen species (ROS) as the main mechanism behind its toxicity causes oxidative stress and subsequent damages to lipids, proteins, and DNA. Therefore, antioxidants along with chelating agents have shown promising outcomes against Cd-induced toxicity. Curcumin with various beneficial effects and medical efficacy has been evaluated for its inhibitory activities against biological impairments caused by Cd. Thus, this article is intended to address the effectiveness of curcumin against toxicity following Cd entry. Curcumin can afford to attenuate lipid peroxidation, glutathione depletion, alterations in antioxidant enzyme, and so forth through scavenging and chelating activities or Nrf2/Keap1/ARE pathway induction. © 2017 BioFactors, 43(5):645-661, 2017.

Nrf2 Inhibits Periodontal Ligament Stem Cell Apoptosis under Excessive Oxidative Stress

The present study aimed to analyze novel mechanisms underlying Nrf2-mediated anti-apoptosis in periodontal ligament stem cells (PDLSCs) in the periodontitis oxidative microenvironment. We created an oxidative stress model with H₂O₂-treated PDLSCs. We used real-time PCR, Western blotting, TUNEL staining, fluorogenic assay and transfer genetics to confirm the degree of oxidative stress and apoptosis as well as the function of nuclear factor-erythroid 2-related factor 2 (Nrf2). We demonstrated that with upregulated levels of reactive oxygen species (ROS) and malondialdehyde (MDA), the effect of oxidative stress was obvious under H₂O₂ treatment. Oxidative molecules were altered after the H₂O₂ exposure, whereby the signaling of Nrf2 was activated with an increase in its downstream effectors, heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1) and γ-glutamyl cysteine synthetase (γ-GCS). Additionally, the apoptosis levels gradually increased with oxidative stress by the upregulation of caspase-9, caspase-3, Bax and c-Fos levels in addition to the downregulation of Bcl-2. However, there was no alterations in levels of caspase-8. The enhanced antioxidant effect could not mitigate the occurrence of apoptosis. Furthermore, Nrf2 overexpression effectively improved the anti-oxidative levels and increased cell proliferation. At the same time, overexpression effectively restrained TUNEL staining and decreased the molecular levels of caspase-9, caspase-3, Bax and c-Fos, but not that of caspase-8. In contrast, silencing the expression of Nrf2 levels had the opposite effect. Collectively, Nrf2 alleviates PDLSCs via its effects on regulating oxidative stress and anti-intrinsic apoptosis by the activation of oxidative enzymes.

Heat shock proteins and kidney disease: perspectives of HSP therapy

Heat shock proteins (HSPs) mediate a diverse range of cellular functions, prominently including folding and regulatory processes of cellular repair. A major property of these remarkable proteins, dependent on intracellular or extracellular location, is their capacity for immunoregulation that optimizes immune activity while avoiding hyperactivated inflammation. In this review, recent investigations are described, which examine roles of HSPs in protection of kidney tissue from various traumatic influences and demonstrate their potential for clinical management of nephritic disease. The HSP70 class is particularly attractive in this respect due to its multiple protective effects. The review also summarizes current understanding of HSP bioactivity in the pathophysiology of various kidney diseases, including acute kidney injury, diabetic nephropathy, chronic glomerulonephritis, and lupus nephritis-along with other promising strategies for their remediation, such as DNA vaccination.

Activation of Wnt/β-catenin signalling is required for TGF-β/Smad2/3 signalling during myofibroblast proliferation

Fibrosis in animal models and human diseases is associated with aberrant activation of the Wnt/β-catenin pathway. Despite extensive research efforts, effective therapies are still not available. Myofibroblasts are major effectors, responsible for extracellular matrix deposition. Inhibiting the proliferation of the myofibroblast is crucial for treatment of fibrosis. Proliferation of myofibroblasts can have many triggering effects that result in fibrosis. In recent years, the Wnt pathway has been studied as an underlying factor as a primary contributor to fibrotic diseases. These efforts notwithstanding, the specific mechanisms by which Wnt-mediated promotes fibrosis reaction remain obscure. The central role of the transforming growth factor-β (TGF-β) and myofibroblast activity in the pathogenesis of fibrosis has become generally accepted. The details of interaction between these two processes are not obvious. The present investigation was conducted to evaluate the level of sustained expression of fibrosis iconic proteins (vimentin, α-SMA and collagen I) and the TGF-β signalling pathway that include smad2/3 and its phosphorylated form p-smad2/3. Detailed analysis of the possible molecular mechanisms mediated by β-catenin revealed epithelial-mesenchymal transition and additionally demonstrated transitions of fibroblasts to myofibroblast cell forms, along with increased activity of β-catenin in regulation of the signalling network, which acts to counteract autocrine TGF-β/smad2/3 signalling. A major outcome of this study is improved insight into the mechanisms by which epithelial and mesenchymal cells activated by TGFβ1-smad2/3 signalling through Wnt/β-catenin contribute to lung fibrosis.

Blood-based omic profiling supports female susceptibility to tobacco smoke-induced cardiovascular diseases

We recently reported that differential gene expression and DNA methylation profiles in blood leukocytes of apparently healthy smokers predicts with remarkable efficiency diseases and conditions known to be causally associated with smoking, suggesting that blood-based omic profiling of human populations may be useful for linking environmental exposures to potential health effects. Here we report on the sex-specific effects of tobacco smoking on transcriptomic and epigenetic features derived from genome-wide profiling in white blood cells, identifying 26 expression probes and 92 CpG sites, almost all of which are affected only in female smokers. Strikingly, these features relate to numerous genes with a key role in the pathogenesis of cardiovascular disease, especially thrombin signaling, including the thrombin receptors on platelets F2R (coagulation factor II (thrombin) receptor; PAR1) and GP5 (glycoprotein 5), as well as HMOX1 (haem oxygenase 1) and BCL2L1 (BCL2-like 1) which are involved in protection against oxidative stress and apoptosis, respectively. These results are in concordance with epidemiological evidence of higher female susceptibility to tobacco-induced cardiovascular disease and underline the potential of blood-based omic profiling in hazard and risk assessment.

Genetic polymorphism of heme oxygenase 1 promoter in the occurrence and severity of chronic obstructive pulmonary disease: a meta-analysis

Heme oxygenase 1 (HMOX1) plays an important role in the development of chronic obstructive pulmonary disease (COPD). However, the association of HMOX1 length polymorphism in promoter region to the risk and severity of COPD has not been well studied. In this study, we searched the databases including PubMed, EMBASE, Cochrane Library and China National Knowledge Infrastructure (CNKI) and extracted the information from related articles. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to study the effect of HMOX1 polymorphism on the risk and severity of COPD. As a result, nine studies were included for this meta‐analysis. Higher frequencies of L allele and type I genotype (containing at least one L allele) were found in patients with COPD (for L allele, OR 2.02, 95% CI: 1.32–3.11, P = 0.001; for type I genotype, OR 1.82, 95% CI: 1.28–2.61, P = 0.001), especially in Asian population (for L allele, OR 2.23, 95% CI: 1.68–2.95, P < 0.001; for type I genotype, OR 2.02, 95% CI: 1.51–2.70, P < 0.001). Genotyping method, source of control subjects, literature quality and language also affected the results to some extent. However, there was little difference in HMOX1 genotypes distribution in patients with COPD with different severity. Our study indicated L allele and type I genotype were related to the susceptibility but not the severity of COPD.

Autophagy: an adaptive physiological countermeasure to cellular senescence and ischaemia/reperfusion-associated cardiac arrhythmias

Oxidative stress placed on tissues that involved in pathogenesis of a disease activates compensatory metabolic changes, such as DNA damage repair that in turn causes intracellular accumulation of detritus and ‘proteotoxic stress’, leading to emergence of ‘senescent’ cellular phenotypes, which express high levels of inflammatory mediators, resulting in degradation of tissue function. Proteotoxic stress resulting from hyperactive inflammation following reperfusion of ischaemic tissue causes accumulation of proteinaceous debris in cells of the heart in ways that cause potentially fatal arrhythmias, in particular ventricular fibrillation (VF). An adaptive response to VF is occurrence of autophagy, an intracellular bulk degradation of damaged macromolecules and organelles that may restore cellular and tissue homoeostasis, improving chances for recovery. Nevertheless, depending on the type and intensity of stressors and inflammatory responses, autophagy may become pathological, resulting in excessive cell death. The present review examines the multilayered defences that cells have evolved to reduce proteotoxic stress by degradation of potentially toxic material beginning with endoplasmic reticulum‐associated degradation, and the unfolded protein response, which are mechanisms for removal from the endoplasmic reticulum of misfolded proteins, and then progressing through the stages of autophagy, including descriptions of autophagosomes and related vesicular structures which process material for degradation and autophagy‐associated proteins including Beclin‐1 and regulatory complexes. The physiological roles of each mode of proteotoxic defence will be examined along with consideration of how emerging understanding of autophagy, along with a newly discovered regulatory cell type called telocytes, may be used to augment existing strategies for the prevention and management of cardiovascular disease.

Curcumin use in pulmonary diseases: State of the art and future perspectives

Curcumin (diferuloylmethane) is a yellow pigment present in the spice turmeric (Curcuma longa). It has been used for centuries in Ayurveda (Indian traditional medicine) for the treatment of several diseases. Over the last several decades, the therapeutic properties of curcumin have slowly been elucidated. It has been shown that curcumin has pleiotropic effects, regulating transcription factors (e.g., NF-kB), cytokines (e.g., IL6, TNF-alpha), adhesion molecules (e.g., ICAM-1), and enzymes (e.g., MMPs) that play a major role in inflammation and cancerogenesis. These effects may be relevant for several pulmonary diseases that are characterized by abnormal inflammatory responses, such as asthma or chronic obstructive pulmonary disease, acute respiratory distress syndrome, pulmonary fibrosis, and acute lung injury. Furthermore, some preliminary evidence suggests that curcumin may have a role in the treatment of lung cancer. The evidence for the use of curcumin in pulmonary disease is still sparse and has mostly been obtained using either in vitro or animal models. The most important issue with the use of curcumin in humans is its poor bioavailability, which makes it necessary to use adjuvants or curcumin nanoparticles or liposomes. The aim of this review is to summarize the available evidence on curcumin's effectiveness in pulmonary diseases, including lung cancer, and to provide our perspective on future research with curcumin so as to improve its pharmacological effects, as well as provide additional evidence of curcumin's efficacy in the treatment of pulmonary diseases.

Anti-Atherogenic Properties of Allium ursinum Liophylisate: Impact on Lipoprotein Homeostasis and Cardiac Biomarkers in Hypercholesterolemic Rabbits

The present investigation evaluates the capacity of Allium ursinum (wild garlic) leaf lyophilisate (WGLL; alliin content: 0.261%) to mitigate cardiovascular damage in hypercholesterolemic rabbits. New Zealand rabbits were divided into three groups: (i) cholesterol-free rabbit chow (control); (ii) rabbit chow containing 2% cholesterol (hypercholesterolemic, HC); (iii) rabbit chow containing 2% cholesterol + 2% WGLL (hypercholesterolemic treated, HCT); for eight weeks. At the zero- and eight-week time points, echocardiographic measurements were made, along with the determination of basic serum parameters. Following the treatment period, after ischemia-reperfusion injury, hemodynamic parameters were measured using an isolated working heart model. Western blot analyses of heart tissue followed for evaluating protein expression and histochemical study for the atheroma status determination. WGLL treatment mediated increases in fractional shortening; right ventricular function; peak systolic velocity; tricuspidal annular systolic velocity in live animals; along with improved aortic and coronary flow. Western blot analysis revealed WGLL-associated increases in HO-1 protein and decreases in SOD-1 protein production. WGLL-associated decreases were observed in aortic atherosclerotic plaque coverage, plasma ApoB and the activity of LDH and CK (creatine kinase) in plasma. Plasma LDL was also significantly reduced. The results clearly demonstrate that WGLL has complex cardioprotective effects, suggesting future strategies for its use in prevention and therapy for atherosclerotic disorders.

ROS/oxidative stress signaling in osteoarthritis

Osteoarthritis is the most common joint disorder with increasing prevalence due to aging of the population. Its multi-factorial etiology includes oxidative stress and the overproduction of reactive oxygen species, which regulate intracellular signaling processes, chondrocyte senescence and apoptosis, extracellular matrix synthesis and degradation along with synovial inflammation and dysfunction of the subchondral bone. As disease-modifying drugs for osteoarthritis are rare, targeting the complex oxidative stress signaling pathways would offer a valuable perspective for exploration of potential therapeutic strategies in the treatment of this devastating disease.