Mitochondrial dysfunction and insulin resistance: the contribution of dioxin-like substances

Drug-induced mitochondrial toxicity: Risks of developing glucose handling impairments

Mitochondrial impairment has been associated with the development of insulin resistance, the hallmark of type 2 diabetes mellitus (T2DM). However, the relationship between mitochondrial impairment and insulin resistance is not fully elucidated due to insufficient evidence to support the hypothesis. Insulin resistance and insulin deficiency are both characterised by excessive production of reactive oxygen species and mitochondrial coupling. Compelling evidence states that improving the function of the mitochondria may provide a positive therapeutic tool for improving insulin sensitivity. There has been a rapid increase in reports of the toxic effects of drugs and pollutants on the mitochondria in recent decades, interestingly correlating with an increase in insulin resistance prevalence. A variety of drug classes have been reported to potentially induce toxicity in the mitochondria leading to skeletal muscle, liver, central nervous system, and kidney injury. With the increase in diabetes prevalence and mitochondrial toxicity, it is therefore imperative to understand how mitochondrial toxicological agents can potentially compromise insulin sensitivity. This review article aims to explore and summarise the correlation between potential mitochondrial dysfunction caused by selected pharmacological agents and its effect on insulin signalling and glucose handling. Additionally, this review highlights the necessity for further studies aimed to understand drug-induced mitochondrial toxicity and the development of insulin resistance.

Pesticides and pancreatic adenocarcinoma: A transversal epidemiological, environmental and mechanistic narrative review

Pancreatic adenocarcinoma (PA) incidence is rising worldwide, especially in France. The evolution of known risk factors such as tobacco smoking, obesity, type 2 diabetes, chronic pancreatitis, or constitutional mutations is not sufficient to explain this trend. Pesticides are known risk factors in other malignancies. Previous studies have outlined pesticides' influence in PA, such as dichlorodiphenyltrichloroethane as plausible risk factors. The general population is directly or indirectly exposed to pesticides through air, food or water. Some of these chemicals may accumulate in the body all along lifetime and may harm carriers. The toxic mixing effects of these chemicals are not well documented. Several hypotheses have been put forward to explain how pesticides can induce indirect (fatty pancreas, induced diabetes) or direct (oxidative stress, cell damage) carcinogenesis in pancreatic cells through inflammation. A strong corpus exists acknowledging pesticides as a PA risk factor. However, published studies do not provide a sufficient level of evidence to prove causality and current prospective case-control studies are still ongoing.

Low-Dose Dioxin Reduced Glucose Uptake in C2C12 Myocytes: The Role of Mitochondrial Oxidative Stress and Insulin-Dependent Calcium Mobilization

Chronic exposure to some environmental polluting chemicals (EPCs) is strongly associated with metabolic syndrome, and insulin resistance is a major biochemical abnormality in the skeletal muscle in patients with metabolic syndrome. However, the causal relationship is inconsistent and little is known about how EPCs affect the insulin signaling cascade in skeletal muscle. Here, we investigated whether exposure to 100 pM of 2,3,7,8-tetrachlorodibenzodioxin (TCDD) as a low dose of dioxin induces insulin resistance in C2C12 myocytes. The treatment with TCDD inhibited the insulin-stimulated glucose uptake and translocation of glucose transporter 4 (GLUT4). The low-dose TCDD reduced the expression of insulin receptor β (IRβ) and insulin receptor substrate (IRS)-1 without affecting the phosphorylation of Akt. The TCDD impaired mitochondrial activities, leading to reactive oxygen species (ROS) production and the blockage of insulin-induced Ca2+ release. All TCDD-mediated effects related to insulin resistance were still observed in aryl hydrocarbon receptor (AhR)-deficient myocytes and prevented by MitoTEMPO, a mitochondria-targeting ROS scavenger. These results suggest that low-dose TCDD stress may induce muscle insulin resistance AhR-independently and that mitochondrial oxidative stress is a novel therapeutic target for dioxin-induced insulin resistance.

Obesogens in Foods

Obesogens, as environmental endocrine-disrupting chemicals, are supposed to have had an impact on the prevalence of rising obesity around the world over the last forty years. These chemicals are probably able to contribute not only to the development of obesity and metabolic disturbances in individuals, but also in their progeny, having the capability to epigenetically reprogram genetically inherited set-up points for body weight and body composition control during critical periods of development, such as fetal, early life, and puberty. In individuals, they may act on myriads of neuro-endocrine–immune metabolic regulatory pathways, leading to pathophysiological consequences in adipogenesis, lipogenesis, lipolysis, immunity, the influencing of central appetite and energy expenditure regulations, changes in gut microbiota–intestine functioning, and many other processes. Evidence-based medical data have recently brought much more convincing data about associations of particular chemicals and the probability of the raised risk of developing obesity. Foods are the main source of obesogens. Some obesogens occur naturally in food, but most are environmental chemicals, entering food as a foreign substance, whether in the form of contaminants or additives, and they are used in a large amount in highly processed food. This review article contributes to a better overview of obesogens, their occurrence in foods, and their impact on the human organism.

Clinical Value of Serum Mitochondria-Inhibiting Substances in Assessing Renal Hazards: A Community-Based Prospective Study in Korea

BACKGROUND

Mitochondrial dysfunction is strongly associated with several kidney diseases. However, no studies have evaluated the potential renal hazards of serum mitochondria-inhibiting substance (MIS) and aryl hydrocarbon receptor ligand (AhRL) levels.

METHODS

We used serum level of MIS and AhRL and clinical renal outcomes from 1,511 participants of a prospective community-based cohort in Ansung. MIS was evaluated based on intracellular adenosine triphosphate (MIS-ATP) or reactive oxygen species (MIS-ROS) generation measured using cell-based assays.

RESULTS

During a mean 6.9-year follow-up, 84 participants (5.6%) developed a rapid decline in kidney function. In the lowest quartile group of MIS-ATP, patients were older and had metabolically deleterious parameters. In multivariate logistic regression analysis, higher MIS-ATP was associated with decreased odds for rapid decline: the odds ratio (OR) of 1% increase was 0.977 (95% confidence interval [CI], 0.957 to 0.998; P=0.031), while higher MIS-ROS was marginally associated with increased odds for rapid decline (OR, 1.014; 95% CI, 0.999 to 1.028; P=0.055). However, serum AhRL was not associated with the rapid decline in kidney function. In subgroup analysis, the renal hazard of MIS was particularly evident in people with hypertension and low baseline kidney function.

CONCLUSION

Serum MIS was independently associated with a rapid decline in kidney function, while serum AhRL was not. The clinical implication of renal hazard on serum MIS requires further evaluation in future studies.

Prenatal exposure to persistent organic pollutants and markers of obesity and cardiometabolic risk in Spanish adolescents

BACKGROUND

Prenatal exposure to persistent organic pollutants (POPs) has been linked to cardiometabolic (CM) risk factors in childhood, but there are no studies evaluating the persistence of these associations into adolescence, a period of relevant changes in endocrine-dependent organ systems and rapid increases in lean and fat mass. We examined the associations of prenatal POP exposures with body mass index (BMI) from age 4 to 18 years, and with other CM risk markers in adolescence.

METHODS

We analysed 379 children from the Spanish INMA-Menorca birth cohort study with measured cord blood POP concentrations. We calculated BMI z-scores at ages 4, 6, 11, 14 and 18 years using the WHO growth reference. Body fat % was measured at 11 and 18 years and waist-to-height ratio (WHtR) and blood pressure (BP) at 11, 14 and 18 years. We measured CM biomarkers in fasting blood collected at age 14 years and calculated a CM-risk score as the sum of the sex-, and age-specific z-scores for waist circumference, mean arterial BP, homeostatic model assessment of insulin resistance, fasting blood triglycerides, and high-density lipoprotein cholesterol (HDL-C) (n = 217). Generalised estimating equations and multivariate linear regression models assessed the associations with repeated and single time-point measures, respectively.

RESULTS

Hexachlorobenzene (HCB) exposure in the third tertile, compared to the first tertile, was associated with higher BMI (β = 0.24; 95% CI: 0.01, 0.47) and WHtR z-score (β = 0.27; 95% CI: 0.04, 0.51). A continuous increase in HCB was associated with an elevated body fat % (β per 10-fold increase = 4.21; 95% CI: 0.51, 7.92), systolic BP (β = 0.32; 95% CI: 0.02, 0.64) and diastolic BP z-score (β = 0.32; 95% CI: 0.02, 0.62) across all ages, and with higher CM-risk score (β = 1.59; 95% CI: 0.02, 3.18) and lipid biomarkers (total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C)) at 14 years. Dichlorodiphenyltrichloroethane (p,p'-DDT) exposure was non-monotonically associated with BMI and systolic BP. p,p'-DDE and Σ-polychlorinated biphenyls (PCBs) (sum of congeners 118, 138, 153, 180) were not associated with adiposity or BP. p,p'-DDT exposure was associated with an increased CM-risk score, and ΣPCBs concentrations with LDL-C in all adolescents and with total cholesterol only in girls (p-sex interaction = 0.05).

CONCLUSION

This first longitudinal study from 4 to 18 years suggests that the previously reported POP associations with child BMI persist later in adolescence and that prenatal POP exposures are associated with major risk factors for adult CM syndrome.

Hallmarks of Health

Health is usually defined as the absence of pathology. Here, we endeavor to define health as a compendium of organizational and dynamic features that maintain physiology. The biological causes or hallmarks of health include features of spatial compartmentalization (integrity of barriers and containment of local perturbations), maintenance of homeostasis over time (recycling and turnover, integration of circuitries, and rhythmic oscillations), and an array of adequate responses to stress (homeostatic resilience, hormetic regulation, and repair and regeneration). Disruption of any of these interlocked features is broadly pathogenic, causing an acute or progressive derailment of the system coupled to the loss of numerous stigmata of health.

Potential role of aryl hydrocarbon receptor signaling in childhood obesity

BACKGROUND

There is a growing concern that junk food has contributed to the childhood obesity epidemic. Recently, experimental studies suggested that the aryl hydrocarbon receptor (AHR) gene is strongly linked to western diet-induced obesity.

AIM

This study investigated the potential role of AHR signaling in childhood obesity and the possible associations of the AHR-aryl hydrocarbon receptor repressor (AHRR)-cytochrome P450 1B1 (CYP1B1) axis with fatty acid homeostasis and the appetite-related hormones, leptin and ghrelin.

SUBJECTS AND METHODS

The study included 80 children; 54 obese and 26 non-obese of matched age and sex. Demographic data, anthropometric measurements, and lipid profile were assessed. Expression of AHR signaling genes was analyzed in blood cells by qRT-PCR. Serum insulin, leptin and ghrelin levels were measured using ELISA.

RESULTS

The statistical power of this study, calculated using G*Power version 3.1.9.2, was 90% (α = 0.05). AHR and CYP1B1 gene expression levels were upregulated in the obese group compared to controls, whereas AHRR, stearoyl-CoA desaturase 1 (SCD1), and peroxisome proliferator-activated receptor-γ₂ (PPARγ₂) were downregulated. Serum leptin correlated positively, while serum ghrelin correlated negatively with both AHR and CYP1B1. Stratification of obese children by age revealed more activated AHR signaling in younger than in older children. Receiver-operating-characteristic (ROC) analysis revealed that AHR, AHRR and CYP1B1 could discriminate between obese and normal weight children. Multivariate analysis showed that AHRR, CYP1B1 and ghrelin could be significant independent predictors of obesity.

CONCLUSION

This study provides new insights into the molecular mechanisms contributing to childhood obesity by revealing alterations in the AHR-AHRR-CYP1B1 axis, which could serve as a promising therapeutic target for childhood obesity.

Persistent Organic Pollutants as Risk Factors for Obesity and Diabetes

PURPOSE OF REVIEW

The rising prevalence of obesity and diabetes cannot be fully explained by known risk factors, such as unhealthy diet, a sedentary lifestyle, and family history. This review summarizes the available studies linking persistent organic pollutants (POPs) to obesity and diabetes and discusses plausible underlying mechanisms.

RECENT FINDINGS

Increasing evidence suggest that POPs may act as obesogens and diabetogens to promote the development of obesity and diabetes and induce metabolic dysfunction. POPs are synthesized chemicals and are used widely in our daily life. These chemicals are resistant to degradation in chemical or biological processes, which enable them to exist in the environment persistently and to be bio-accumulated in animal and human tissue through the food chain. Increasingly, epidemiologic studies suggest a positive association between POPs and risk of developing diabetes. Understanding the relationship of POPs with obesity and diabetes may shed light on preventive strategies for obesity and diabetes.

Potential contribution of insecticide exposure and development of obesity and type 2 diabetes

The introduction of insecticides has greatly improved agricultural productivity and human nutrition; however, the wide use of insecticides has also sparked growing concern over their health impacts. Increased rate of cancers, neurodegenerative disorders, reproductive dysfunction, birth defects, respiratory diseases, cardiovascular diseases and aging have been linked with insecticide exposure. Meanwhile, a growing body of evidence is suggesting that exposure to insecticides can also potentiate the risk of obesity and type 2 diabetes. This review summarizes the relationship between insecticide exposure and development of obesity and type 2 diabetes using epidemiological and rodent animal studies, including potential mechanisms. The evidence as a whole suggests that exposure to insecticides is linked to increased risk of obesity and type 2 diabetes.

Disruption of Ah Receptor Signaling during Mouse Development Leads to Abnormal Cardiac Structure and Function in the Adult

The Developmental Origins of Health and Disease (DOHaD) Theory proposes that the environment encountered during fetal life and infancy permanently shapes tissue physiology and homeostasis such that damage resulting from maternal stress, poor nutrition or exposure to environmental agents may be at the heart of adult onset disease. Interference with endogenous developmental functions of the aryl hydrocarbon receptor (AHR), either by gene ablation or by exposure in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent AHR ligand, causes structural, molecular and functional cardiac abnormalities and altered heart physiology in mouse embryos. To test if embryonic effects progress into an adult phenotype, we investigated whether Ahr ablation or TCDD exposure in utero resulted in cardiac abnormalities in adult mice long after removal of the agent. Ten-months old adult Ahr^-/- and in utero TCDD-exposed Ahr^+/+ mice showed sexually dimorphic abnormal cardiovascular phenotypes characterized by echocardiographic findings of hypertrophy, ventricular dilation and increased heart weight, resting heart rate and systolic and mean blood pressure, and decreased exercise tolerance. Underlying these effects, genes in signaling networks related to cardiac hypertrophy and mitochondrial function were differentially expressed. Cardiac dysfunction in mouse embryos resulting from AHR signaling disruption seems to progress into abnormal cardiac structure and function that predispose adults to cardiac disease, but while embryonic dysfunction is equally robust in males and females, the adult abnormalities are more prevalent in females, with the highest severity in Ahr^-/- females. The findings reported here underscore the conclusion that AHR signaling in the developing heart is one potential target of environmental factors associated with cardiovascular disease.

A cross-sectional analysis of dioxins and health effects in municipal and private waste incinerator workers in Japan

This cross-sectional study was intended to examine health effects of 678 male workers employed during an 8-yr period from 2000 to 2007 at 36 municipal and private waste incineration plants in Japan. Blood samples were obtained for analysis of concentrations of dioxins including coplanar polychlorinated biphenyls (coplanar PCBs) and evaluation of health effects. Health effects including diabetes were surveyed via a physician's interview or clinical data from blood samples. There was a certain difference in serum concentrations of polychlorinated dibenzofurans (PCDFs) between the incinerator workers and Japanese general population, although no differences in the concentrations of total dioxins or polychlorinated dibenzo-p-dioxins (PCDDs) were found between the two groups. A few positive correlations between serum levels of PCDDs and PCDFs and the results of laboratory and physiological tests were found, but coplanar PCBs showed significant relations with 14 parameters of the tests. The background serum levels of PCDDs, PCDFs and total dioxins were significantly associated with the prevalence of diabetes. No essential differences in serum concentrations of total dioxins and in prevalence of diabetes between our subjects and the general population suggested that the incinerator workers were marginally exposed to dioxins in the workplace without any recognizable adverse health effects.

Persistent organic pollutants and biomarkers of diabetes risk in a cohort of Great Lakes sport caught fish consumers

BACKGROUND

Exposure to persistent organic pollutants (POPs) is associated with increased diabetes risk, although the mechanism of action is not well delineated.

METHODS

We investigated established diabetes biomarkers that could implicate potential mechanistic pathways, including C-reactive protein (CRP), a marker of systemic inflammation; gamma glutamyl transferase (GGT), a liver enzyme associated with oxidative stress; and adiponectin, an adipokine modulating glucose regulation and fatty acid oxidation. These biomarkers as well as hemoglobin A1c (HA1c), and POPs [polychlorinated biphenyls (PCBs), p,p-dichlorodiphenyldichloroethylene (DDE) and polybrominated diphenyl ethers (PBDEs)] were measured in a cohort of Great Lakes sport caught fish (GLSCF) consumers. We examined associations of POPs and fish consumption with HA1c and incident diabetes, and evaluated mediation and moderation by the diabetes biomarkers.

RESULTS

Odds of incident diabetes were elevated with exposure to DDE and PCBs. DDE and PCB 118 were positively, and fish meals were inversely, associated with HA1c. CRP was inversely associated with saltwater and total fish meals, particularly in persons with higher adiposity, but did not mediate the associations of fish meals with HA1c. There were few associations of POPs with adiponectin, CRP and GGT, with the exception of positive associations of PCB 118 with GGT, PBDEs with GGT in older persons, and PBDEs with adiponectin. Adiponectin, CRP and GGT did not mediate associations of DDE and PCBs with HA1c or incident diabetes. However, the association of DDE with HA1c was stronger in persons with higher CRP, GGT and BMI, and lower adiponectin, while the association of PCB 118 with HA1c was stronger in persons with higher GGT.

CONCLUSIONS

These findings suggest that adiponectin, CRP and GGT did not mediate effects of POPs on diabetes or HA1c. However, POPs may have stronger effects on blood glucose in persons at higher risk for diabetes.

Serum aryl hydrocarbon receptor ligand activity is associated with insulin resistance and resulting type 2 diabetes

AIMS

Dioxin or dioxin-like compounds are ligands of the aryl hydrocarbon receptor (AhR), which is a ligand-activated nuclear transcription factor. There are limited studies about the association of serum AhR ligand activities and T2DM. Our objective was to investigate the association of serum AhR ligand activities with T2DM and its related metabolic parameters.

METHODS

This case-control study involved 83 subjects with T2DM as well as age-, sex-, and body mass index (BMI)-matched subjects with impaired glucose tolerance (IGT, n = 130) and normal glucose tolerance (NGT, n = 83). Serum AhR ligand activities were measured using a cell-based AhR ligand assay and standardized as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDDeq, pmol/l).

RESULTS

The T2DM group had the highest AhR ligand activities compared to the IGT and NGT groups [median (interquartile range), 68.1 (53.1, 81.5), 60.2 (45.8, 75.1), and 53.3 (46.1, 63.7) pmol/l, respectively; P = 0.003]. In the multivariate analysis, the log2-transformed TCDDeq levels were significantly associated with the risk of T2DM after adjusting for age, sex, and BMI (odds ratio 2.26, 95 % confidence interval 1.34-3.82; P = 0.002). In nondiabetic subjects, serum AhR ligand activities showed a positive correlation with fasting glucose and insulin concentrations and the homeostasis model assessment of insulin resistance, but showed a negative correlation with adiponectin concentrations.

CONCLUSIONS

Serum AhR ligand activities were higher in the T2DM group and were correlated with the parameters of insulin resistance. Further investigation is required to elucidate the causal relationship between AhR ligand activity and T2DM.

Aryl hydrocarbon receptor deficiency protects mice from diet-induced adiposity and metabolic disorders through increased energy expenditure

BACKGROUND/OBJECTIVES

Epidemics of obesity and diabetes are escalating. High-calorie/high-fat food is a major cause for these global health issues, but molecular mechanisms underlying high-fat, diet-induced obesity are still not well understood. The aryl hydrocarbon receptor (AhR), a transcription factor that acts as a xenobiotic sensor, mediates environmental toxicant-induced obesity, insulin resistance and development of diabetes. AhR also influences lipid metabolism and diet-induced obesity. The effects of AhR deficiency on diet-induced obesity, hepatic steatosis and insulin resistance were examined.

METHODS

Male wild-type (WT), AhR null (AhR(-/-)) and AhR heterozygote (AhR(+/-)) mice were fed a normal chow diet (NCD, 10% kcal from fat) or a high-fat diet (HFD, 60% kcal from fat) for up to 14 weeks. Adiposity, adipose and liver morphology, insulin signaling, metabolic parameters and gene profiles were assessed.

RESULTS

AhR deficiency protected against HFD-induced obesity, hepatic steatosis, insulin resistance and inflammation. Moreover, AhR deficiency preserved insulin signaling in major metabolic tissues. These protective effects result from a higher energy expenditure in AhR-deficient mice compared with WT. Levels of transcript for both the thermogenic gene, uncoupling protein 1 (Ucp1), in brown adipose tissue and mitochondrial β-oxidation genes in muscle were significantly higher in AhR(-/-) and AhR(+/-) mice compared with WT.

CONCLUSIONS

This work documents a physiologically relevant function for AhR in regulation of body weight, hepatic fat deposition, insulin sensitivity and energy expenditure under HFD exposure, suggesting that AhR signaling may be developed as a potential therapeutic target for treatment of obesity and metabolic disorders.

The glycated albumin to glycated hemoglobin ratio might not be associated with carotid atherosclerosis in patients with type 1 diabetes

BACKGROUND

The ratio of glycated albumin to glycated hemoglobin (GA/A1c) is known to be elevated in subjects with type 2 diabetes mellitus (T2DM) who had decreased insulin secretion. Additionally, the carotid intima media thickness (IMT) is greater in T2DM patients with higher GA/A1c ratios. We investigated whether increased GA/A1c ratio and IMT are also associated in type 1 diabetes mellitus (T1DM), which is characterized by lack of insulin secretory capacity.

METHODS

In this cross-sectional study, we recruited 81 T1DM patients (33 men, 48 women; mean age 44.1±13.0 years) who underwent carotid IMT, GA, and HbA1c measurements.

RESULTS

The mean GA/A1c ratio was 2.90. Based on these results, we classified the subjects into two groups: group I (GA/A1c ratio <2.90, n=36) and group II (GA/A1c ratio ≥2.90, n=45). Compared with group I, the body mass indexes (BMIs), waist circumferences, and IMTs were lower in group II. GA/A1c ratio was negatively correlated with BMI, urine albumin to creatinine ratio (P<0.001 for both), and both the mean and maximal IMT (P=0.001, both). However, after adjusting the confounding factors, we observed that IMT was no longer associated with GA/A1c ratio.

CONCLUSION

In contrast to T2DM, IMT was not significantly related to GA/A1c ratio in the subjects with T1DM. This suggests that the correlations between GA/A1c ratio and the parameters known to be associated with atherosclerosis in T2DM could be manifested differently in T1DM. Further studies are needed to investigate these relationships in T1DM.

Association of dioxin and other persistent organic pollutants (POPs) with diabetes: epidemiological evidence and new mechanisms of beta cell dysfunction

The worldwide explosion of the rates of diabetes and other metabolic diseases in the last few decades cannot be fully explained only by changes in the prevalence of classical lifestyle-related risk factors, such as physical inactivity and poor diet. For this reason, it has been recently proposed that other "nontraditional" risk factors could contribute to the diabetes epidemics. In particular, an increasing number of reports indicate that chronic exposure to and accumulation of a low concentration of environmental pollutants (especially the so-called persistent organic pollutants (POPs)) within the body might be associated with diabetogenesis. In this review, the epidemiological evidence suggesting a relationship between dioxin and other POPs exposure and diabetes incidence will be summarized, and some recent developments on the possible underlying mechanisms, with particular reference to dioxin, will be presented and discussed.

Coenzyme Q10 ameliorates pain and cartilage degradation in a rat model of osteoarthritis by regulating nitric oxide and inflammatory cytokines

Objective

To investigate the effect of CoenzymeQ10 (CoQ10) on pain severity and cartilage degeneration in an experimental model of rat osteoarthritis (OA).

Materials and Methods

OA was induced in rats by intra-articular injection of monosodium iodoacetate (MIA) to the knee. Oral administration of CoQ10 was initiated on day 4 after MIA injection. Pain severity was assessed by measuring secondary tactile allodynia using the von Frey assessment test. The degree of cartilage degradation was determined by measuring cartilage thickness and the amount of proteoglycan. The mankin scoring system was also used. Expressions of matrix metalloproteinase-13 (MMP-13), interleukin-1β (IL-1β), IL-6, IL-15, inducible nitric oxide synthase (iNOS), nitrotyrosine and receptor for advanced glycation end products (RAGE) were analyzed using immunohistochemistry.

Results

Treatment with CoQ10 demonstrated an antinociceptive effect in the OA animal model. The reduction in secondary tactile allodynia was shown by an increased pain withdrawal latency and pain withdrawal threshold. CoQ10 also attenuated cartilage degeneration in the osteoarthritic joints. MMP-13, IL-1β, IL-6, IL-15, iNOS, nitrotyrosine and RAGE expressions were upregulated in OA joints and significantly reduced with CoQ10 treatment.

Conclusion

CoQ10 exerts a therapeutic effect on OA via pain suppression and cartilage degeneration by inhibiting inflammatory mediators, which play a vital role in OA pathogenesis.

Pesticides and human chronic diseases: evidences, mechanisms, and perspectives

Along with the wide use of pesticides in the world, the concerns over their health impacts are rapidly growing. There is a huge body of evidence on the relation between exposure to pesticides and elevated rate of chronic diseases such as different types of cancers, diabetes, neurodegenerative disorders like Parkinson, Alzheimer, and amyotrophic lateral sclerosis (ALS), birth defects, and reproductive disorders. There is also circumstantial evidence on the association of exposure to pesticides with some other chronic diseases like respiratory problems, particularly asthma and chronic obstructive pulmonary disease (COPD), cardiovascular disease such as atherosclerosis and coronary artery disease, chronic nephropathies, autoimmune diseases like systemic lupus erythematous and rheumatoid arthritis, chronic fatigue syndrome, and aging. The common feature of chronic disorders is a disturbance in cellular homeostasis, which can be induced via pesticides' primary action like perturbation of ion channels, enzymes, receptors, etc., or can as well be mediated via pathways other than the main mechanism. In this review, we present the highlighted evidence on the association of pesticide's exposure with the incidence of chronic diseases and introduce genetic damages, epigenetic modifications, endocrine disruption, mitochondrial dysfunction, oxidative stress, endoplasmic reticulum stress and unfolded protein response (UPR), impairment of ubiquitin proteasome system, and defective autophagy as the effective mechanisms of action.

Increased susceptibility to metabolic syndrome in adult offspring of angiotensin type 1 receptor autoantibody-positive rats

AIMS

Abnormal fetal and early postnatal growth is closely associated with adult-onset metabolic syndrome (MetS). However, the underlying etiological factors remain complex. The presence of the autoantibody against the angiotensin II type 1 receptor (AT1-Ab), a known risk factor for pre-eclampsia, may create a suboptimal intrauterine fetal environment. The current study investigated whether middle-aged offspring of AT1-Ab-positive mothers were prone to metabolic disorder development.

RESULTS

The AT1-Abs was detected in placental trophoblastic cells, capillary endothelium, and milk of pregnant rats actively immunized with the second extracellular loop of the AT1 receptor. AT1-Abs in newborn rats induced vasoconstriction, increased intracellular-free Ca(2+) in vitro, and was undetectable 7 weeks later. Immunized group offspring exhibited increased weight variability and insulin resistance at 40 weeks of age under a normal diet, evidenced by elevated fasting serum insulin and homeostasis model assessment score compared with the vehicle control. To further observe metabolic alterations, the offspring were given a high-sugar diet (containing 20% sucrose) 40-48 weeks postnatally. The fasting plasma glucose in immunized group offspring was markedly increased. Concomitantly, these offspring manifested increased visceral adipose tissue, increased fatty liver, increased triglycerides, decreased high-density lipoprotein cholesterol, and decreased adiponectin levels, indicative of MetS.

INNOVATION

AT1-Abs could be transferred from mother to offspring via the placenta and milk. Moreover, offspring of an AT1-Ab-positive mother were more vulnerable to MetS development in middle age.

CONCLUSION

AT1-Ab-positivity of mothers during pregnancy is a previously unrecognized "silent" risk factor for MetS development in their offspring.