Evaluation of oxidative stress and effectiveness of low-dose glucocorticoid therapy on exacerbation of chronic obstructive pulmonary disease

Association between Tai Chi Yuttari Exercise and Longevity and Prevention of Long-Term Care Need: Survival Analysis in Kitakata City, Japan

This study examined whether participation in Tai Chi Yuttari exercise is associated with a delay in the death and new certification for long-term care need of older adults. Individuals who participated in Tai Chi Yuttari exercise classes in 2011-2015 (participation group) were compared with individuals from the Basic Resident Register of Kitakata City (non-participation group). Death and new certification for long-term care need were selected to evaluate the effectiveness of participation in Tai Chi Yuttari exercise classes. The periods from the start date of the observation to each person's date of occurrence of events were calculated. The Kaplan-Meier method and log-rank test were used to compare survival curves between the groups. A total of 105 and 202 individuals in the participation and non-participation groups, respectively, were observed. Survival duration (χ2 = 8.782, p = 0.003) and the period before receiving certification for long-term care (χ2 = 5.354, p = 0.021) were longer in the participation group than in the non-participation group. In the stratified analysis by sex, survival duration was longer in the participation group in men only (χ2 = 7.875, p = 0.005). Participation in Tai Chi Yuttari exercise might be effective in delaying death, especially in men, and new certification for long-term care.

Glucocorticoid-induced autophagy and apoptosis in bone

Glucocorticoids are widely prescribed to treat various allergic and autoimmune diseases; however, long-term use results in glucocorticoid-induced osteoporosis, characterized by consistent changes in bone remodeling with decreased bone formation as well as increased bone resorption. Not only bone mass but also bone quality decrease, resulting in an increased incidence of fractures. The primary role of autophagy is to clear up damaged cellular components such as long-lived proteins and organelles, thus participating in the conservation of different cells. Apoptosis is the physiological death of cells, and plays a crucial role in the stability of the environment inside a tissue. Available basic and clinical studies indicate that autophagy and apoptosis induced by glucocorticoids can regulate bone metabolism through complex mechanisms. In this review, we summarize the relationship between apoptosis, autophagy and bone metabolism related to glucocorticoids, providing a theoretical basis for therapeutic targets to rescue bone mass and bone quality in glucocorticoid-induced osteoporosis.

Methylmercury-Mediated Oxidative Stress and Activation of the Cellular Protective System

Methylmercury (MeHg) is a well-known neurotoxicant that causes severe intoxication in humans. In Japan, it is referred to as Minamata disease, which involves two characteristic clinical forms: fetal type and adult type depending on the exposed age. In addition to MeHg burden level, individual susceptibility to MeHg plays a role in the manifestation of MeHg toxicity. Research progress has pointed out the importance of oxidative stress in the pathogenesis of MeHg toxicity. MeHg has a high affinity for selenohydryl groups, sulfhydryl groups, and selenides. It has been clarified that such affinity characteristics cause the impairment of antioxidant enzymes and proteins, resulting in the disruption of antioxidant systems. Furthermore, MeHg-induced intracellular selenium deficiency due to the greater affinity of MeHg for selenohydryl groups and selenides leads to failure in the recoding of a UGA codon for selenocysteine and results in the degradation of antioxidant selenoenzyme mRNA by nonsense-mediated mRNA decay. The defect of antioxidant selenoenzyme replenishment exacerbates MeHg-mediated oxidative stress. On the other hand, it has also been revealed that MeHg can directly activate the antioxidant Keap1/Nrf2 signaling pathway. This review summarizes the incidence of MeHg-mediated oxidative stress from the viewpoint of the individual intracellular redox system interactions and the MeHg-mediated aforementioned intracellular events. In addition, the mechanisms of cellular stress pathways and neuronal cell death triggered by MeHg-mediated oxidative stress and direct interactions of MeHg with reactive residues of proteins are mentioned.

Oxidative stress and macrophages: driving forces behind exacerbations of asthma and chronic obstructive pulmonary disease?

Oxidative stress is a common feature of obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD). Lung macrophages are key innate immune cells that can generate oxidants and are known to display aberrant polarization patterns and defective phagocytic responses in these diseases. Whether these characteristics are linked in one way or another and whether they contribute to the onset and severity of exacerbations in asthma and COPD remain poorly understood. Insight into oxidative stress, macrophages, and their interactions may be important in fully understanding acute worsening of lung disease. This review therefore highlights the current state of the art regarding the role of oxidative stress and macrophages in exacerbations of asthma and COPD. It shows that oxidative stress can attenuate macrophage function, which may result in impaired responses toward exacerbating triggers and may contribute to exaggerated inflammation in the airways.

Effects of mode of delivery on pro-oxidant/antioxidant balance in fetal circulation

Objective: This study was undertaken to assess the influence of mode of delivery on the balance between pro-oxidant/antioxidant systems in fetal circulation. Materials and methods: Both umbilical arterial and venous blood samples were obtained from 37 pregnant women who delivered by spontaneous vaginal delivery (VD group) and from 29 pregnant women who delivered by elective cesarean section (CS group). Oxidative stress and antioxidant activity were evaluated by reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP), respectively. Results: The d-ROMs values of the VD group were higher than that of the CS group in both umbilical arterial and venous blood and these differences were found to be statistically significant (p < .01 and p < .01, respectively). The BAP values of only the umbilical arterial blood were found to be statistically significant (p < .01), with values from the VD group being higher than those of the CS group. In all measurements, the d-ROMs values averaged below 120 CARR U and BAP values averaged above 2200 µmol/L. The ratio of BAP/d-ROMs difference was found to be statistically significant (p < .01) only in the umbilical venous blood, with ratios in the VD group being lower than those in the CS group. Conclusions: Our statistical analyses suggest that vaginal delivery has an effect on increasing oxidative stress as a result of the stress of labor and that an elective cesarean section does not impair the mother's oxidative stress status. Furthermore, the high BAP values in all the measurements suggest that neonates just after birth have the ability to cope with oxidative stress. Rationale   In many studies, the diversity of views on the influence of mode of delivery on the redox status of neonates is likely to be caused by the use of different biomarkers to measure either the oxidative stress, the antioxidant activity, or both. Furthermore, incomplete explanation for sampling cord blood in these studies, either arterial, venous blood or both, complicates matters. To solve the above, this study was designed to assess the effects of mode of delivery on both pro-oxidants, via d-ROMs, and antioxidants, via BAP, in both umbilical arterial and venous blood samples obtained just after birth. There are no existing studies of BAP in both umbilical arterial and venous blood to which we can refer. In conclusion, our study suggests that the pro-oxidant/antioxidant balance in neonates just after birth is better than may be expected when compared to the potentials of adults (including pregnant mothers) according to interpretations of BAP/d-ROMs. This can be understood that neonates may have already been endowed with the ability to cope with oxidative stress, as informed by high BAP values in both umbilical arterial and venous blood. Vaginal delivery may have an effect on increasing oxidative stress as a result of the stress of labors (as measured by d-ROMs), and an elective cesarean section, which has better BAP/d-ROMs in umbilical venous blood than that of vaginal delivery, may not impair the mother's oxidative stress status.

Effects of Chlorogenic Acid-Enriched and Hydroxyhydroquinone-Reduced Coffee on Postprandial Fat Oxidation and Antioxidative Capacity in Healthy Men: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial

Chlorogenic acids (CGAs) reduce blood pressure and body fat, and enhance fat metabolism. In roasted coffee, CGAs exist together with the oxidant component hydroxyhydroquinone (HHQ). HHQ counteracts the antihypertensive effects of CGA, but its effects on CGA-induced fat oxidation (FOX) are unknown. Here we assessed the effects of CGA-enriched and HHQ-reduced coffee on FOX. Fifteen healthy male volunteers (age: 38 ± 8 years (mean ± SD); BMI: 22.4 ± 1.5 kg/m²) participated in this crossover study. Subjects consumed the test beverage (coffee) containing the same amount of CGA with HHQ (CGA-HHQ(+)) or without HHQ (CGA-HHQ(−)) for four weeks. Postprandial FOX and the ratio of the biological antioxidant potential (BAP) to the derivatives of reactive oxygen metabolites (d-ROMs) as an indicator of oxidative stress were assessed. After the four-week intervention, postprandial FOX and the postprandial BAP/d-ROMs ratio were significantly higher in the CGA-HHQ(−) group compared with the CGA-HHQ(+) group (4 ± 23 mg/min, group effect: p = 0.040; 0.27 ± 0.74, group effect: p = 0.007, respectively). In conclusion, reducing the amount of HHQ facilitated the postprandial FOX effects of CGA in coffee. Our findings also suggest that the mechanism underlying the inhibition of FOX by HHQ is related to postprandial oxidative stress.

Effect of tumor necrosis factor-α antagonists on oxidative stress in patients with Crohn’s disease

AIM: To investigate changes in oxidative stress in Crohn’s disease (CD) before and after anti-tumor necrosis factor (TNF)-α treatment.

METHODS: A total of 42 patients with active CD, who were scheduled to be treated by anti-TNF-α antibodies, were enrolled. Serum levels of diacron-reactive oxygen metabolites (d-ROM), biological antioxidant potential (BAP), and modified ratio of oxidative stress and antioxidant capacity (m-OA) were measured using the Free Radical Analytical System before and 8 wk after induction of therapy with infliximab or adalimumab. The values for oxidative stress were correlated with disease activity and clinical response as determined by the CD activity index (CDAI) at 8 and 54 wk after the therapy.

RESULTS: Prior to treatment, d-ROM showed significant correlations with CDAI (r = 0.42, P < 0.01). There was a significant negative correlation between m-OA and CDAI before and after treatment (r = -0.48 vs r = -0.42, P < 0.01). CDAI and d-ROM had decreased significantly by 8 wk after treatment (CDAI; 223.3 ± 113.2 vs 158.3 ± 73.4, P < 0.01, d-ROM; 373 ± 133 vs 312 ± 101, P < 0.05). However, neither BAP nor m-OA had changed significantly. In patients who had responded to the treatment at 8 wk, d-ROM, BAP, and m-OA levels before treatment did not differ significantly between patients with and without loss of response.

CONCLUSION: Anti-TNF-α therapy decreases oxidative stress in patients with CD, but does not alter the production of antioxidants. Dysregulation of antioxidants may be associated with the disease.

Oxidative stress and nitric oxide signaling related biomarkers in patients with pulmonary hypertension: a case control study

BACKGROUND

Oxidative stress (OS) and reduced nitric oxide (NO) bioavailability contribute to the pathogenesis of pulmonary hypertension (PH). Whether there are associations between OS and NO signaling biomarkers and whether these biomarkers are associated with the severity of PH remain unclear.

METHODS

Blood samples were collected from 35 healthy controls and 35 patients with pulmonary arterial hypertension (PAH, n = 12) or chronic thromboembolic pulmonary hypertension (CTEPH, n = 23). The mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance index (PVRI) were measured by right heart catheterization. We measured the derivative of reactive oxygen molecules (d-ROMs), biological antioxidant potential (BAP) and superoxide dismutase (SOD) by automatic biochemical analyzer, malondialdehyde (MDA) and asymmetric dimethylarginine (ADMA) by enzyme-linked immunosorbent assay. The relationship between oxidative-antioxidative biomarkers and ADMA, as well as their association with pulmonary hemodynamics, were analyzed.

RESULTS

Compared with age- and gender-matched controls, there was no significant difference of d-ROMs in PAH and CTEPH patients; MDA was increased in CTEPH patients (P = 0.034); BAP and SOD were decreased in PAH (P = 0.014, P < 0.001) and CTEPH patients (P = 0.015, P < 0.001); ADMA level was significantly higher in PAH (P = 0.007) and CTEPH patients (P < 0.001). No association between oxidative-antioxidative biomarkers and ADMA was found. Serum ADMA concentration was correlated with mPAP (r = 0.762, P = 0.006) and PVRI (r = 0.603, P = 0.038) in PAH patients.

CONCLUSIONS

The antioxidative potential and NO signaling are impaired in PAH and CTEPH. Increased serum ADMA level is associated with unfavorable pulmonary hemodynamics in PAH patients. Thus, ADMA may be useful in the severity evaluation and risk stratification of PAH.

Physical and physiological effectiveness of an overall health care program for middle-aged Japanese women with mild obesity: A pilot study

This study aimed to verify the effectiveness of an overall health care program (OHCP) for middle-aged Japanese women through assessing physical and physiological changes. The OHCP consisted of diet modification with natural alternative foods, walking and stretching exercises, and body massage and cupping treatments. Sixty-seven participants were assigned to one of three groups during a 3-year study period (2011–2013). The OHCP was performed for 3 months in each year. After the OHCP, most participants had significant decreases in the blood levels of triglycerides, low-density lipoprotein cholesterol, total cholesterol, alkaline phosphatase, γ-glutamyl transferase, and cholinesterase; body weight; body fat percentage; and body-mass index. The oxidative stress markers varied among the study years; however, a significant decrease in blood reactive oxygen-derived metabolites and a significant increase in the relative antioxidative potential were observed in 2013. In 2013, participants who were randomly selected for autonomic nervous activity measurements immediately before and after body massage and cupping treatments showed a significant predominance in parasympathetic nervous activity after the treatments. These results indicate that the OHCP in the present study is an effective and prompt method as a complementary treatment to improve the pre-obese or mild obese status without any noticeable physiological stress in most middle-aged women. However, because of the limitations of this study, the findings of this study need to be confirmed.

Glucocorticoids and osteocyte autophagy

Glucocorticoids are used for the treatment of inflammatory and autoimmune diseases. While they are effective therapy, bone loss and incident fracture risk are high. While previous studies have found GC effects on both osteoclasts and osteoblasts, our work has focused on the effects of GCs on osteocytes. Osteocytes exposed to low dose GCs undergo autophagy while osteocytes exposed to high doses of GCs or for a prolonged period of time undergo apoptosis.

Glucocorticoid dose determines osteocyte cell fate

In response to cellular insult, several pathways can be activated, including necrosis, apoptosis, and autophagy. Because glucocorticoids (GCs) have been shown to induce both osteocyte apoptosis and autophagy, we sought to determine whether osteocyte cell fate in the presence of GCs was dose dependent by performing in vivo and in vitro studies. Male Swiss-Webster mice were treated with slow-release prednisolone pellets at 1.4, 2.8, and 5.6 mg/kg/d for 28 d. An osteocyte cell line, MLO-Y4 cells, was treated with various doses of dexamethasone. We found that GC treatments dose dependently decreased activation of antioxidant-, autophagy-, and antiapoptosis-focused RT-PCR gene pathways in mouse cortical bone. The activation of antioxidant genes was correlated with autophagy gene expression after the GC treatments. The presence of osteocyte autophagy, as detected by immunostaining for LC3, increased ∼50% at the distal femur cortical bone region but not at trabecular bone region at the 1.4 and 2.8 mg/kg/d GC dose levels. The number of apoptotic osteocytes was increased at the cortical bone region by ∼40% initially observed at the 2.8 mg/kg/d dose level. In addition, the presence of the osteocyte autophagy was associated with an increased protein level of cathepsin K in vitro after the GC treatments. In summary, we found that GC treatment dose-dependently decreased antioxidant gene expression, with lower GC doses activating autophagy, whereas a higher dose increased apoptosis. These data suggest that autophagy may provide a mechanism for osteocytes to survive the stress after GC exposure and provide further insight into how GCs alter bone cell fate.

Impact of a single intracoronary administration of adiponectin on myocardial ischemia/reperfusion injury in a pig model

BACKGROUND

Adiponectin plays a protective role in the development of obesity-linked disorders. We demonstrated that adiponectin exerts beneficial actions on acute ischemic injury in mice hearts. However, the effects of adiponectin treatment in large animals and its feasibility in clinical practice have not been investigated. This study investigated the effects of intracoronary administration of adiponectin on myocardial ischemia-reperfusion (I/R) injury in pigs.

METHODS AND RESULTS

The left anterior descending coronary artery was occluded in pigs for 45 minutes and then reperfused for 24 hours. Recombinant adiponectin protein was given as a bolus intracoronary injection during ischemia. Cardiac functional parameters were measured by a manometer-tipped catheter. Apoptosis was evaluated by terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling staining. Tumor necrosis factor-alpha and interleukin-10 transcripts were analyzed by real-time polymerase chain reaction. Serum levels of derivatives of reactive oxygen metabolites and biological antioxidant potential were measured. Adiponectin protein was determined by immunohistochemical and Western blot analyses. Intracoronary administration of adiponectin protein led to a reduction in myocardial infarct size and improvement of left ventricular function in pigs after I/R. Injected adiponectin protein accumulated in the I/R-injured heart. Adiponectin treatment resulted in decreased tumor necrosis factor-alpha and increased interleukin-10 mRNA levels in the myocardium after I/R. Adiponectin-treated pigs had reduced apoptotic activity in the I/R-injured heart and showed increased biological antioxidant potential levels and decreased derivatives of reactive oxygen metabolite levels in the blood stream after I/R.

CONCLUSIONS

These data suggest that adiponectin protects against I/R injury in a preclinical pig model through its ability to suppress inflammation, apoptosis, and oxidative stress. Administration of intracoronary adiponectin could be a useful adjunctive therapy for acute myocardial infarction.

Bibliography. Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 November 2007 and 31 October 2008 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.