Cigarette smoke exposure and hypercholesterolemia increase mitochondrial damage in cardiovascular tissues

ZLN005, a PGC-1α agonist, delays photoreceptor degeneration by enhancing mitochondrial biogenesis in a murine model of retinitis pigmentosa

Retinitis pigmentosa (RP) is a hereditary neurodegenerative disease characterized by the degeneration of photoreceptors caused by mutations in various genes. Increasing evidence suggests that mitochondrial biogenesis plays a critical role in many neurodegenerative diseases. This study investigated the role of mitochondrial biogenesis in rd1 mice, a widely recognized model of RP. Male C57BL/6 mice and age-matched rd1 mice were used for in vivo experiments, while H2O2 was employed on 661w cells to establish an in vitro model. Our findings revealed that mitochondrial biogenesis and the regulatory PGC-1α/NRF-1/TFAM pathway were significantly downregulated in rd1 mice. Treatment with ZLN005, a PGC-1α agonist, markedly improved visual function in rd1 mice and alleviated thinning of the retinal outer nuclear layer. Additionally, ZLN005 enhanced mitochondrial biogenesis and restored mitochondrial function in photoreceptors. Further analysis in vitro confirmed that ZLN005 rescued photoreceptor degeneration by promoting mitochondrial biogenesis through the PGC-1α/NRF-1/TFAM pathway. In summary, our results highlight the critical role of mitochondrial biogenesis and the PGC-1α/NRF-1/TFAM pathway in the progression of RP. This offers a potential strategy to delay photoreceptor degeneration in RP by maintaining mitochondrial function and could be combined with existing therapies for improving treatment outcomes through synergistic pathways.

Mitochondrial Dysfunction and Atherosclerosis: The Problem and the Search for Its Solution

Background/Objectives: This review has been prepared to promote interest in the interdisciplinary study of mitochondrial dysfunction (MD) and atherosclerosis. This review aims to describe the state of this problem and indicate the direction for further implementation of this knowledge in clinical medicine. Methods: Extensive research of the literature was implemented to elucidate the role of the molecular mechanisms of MD in the pathogenesis of atherosclerosis. Results: A view on the pathogenesis of atherosclerosis through the prism of knowledge about MD is presented. MD is the cause and primary mechanism of the onset and progression of atherosclerosis. It is proposed that this problem be considered in the context of a continuum. Conclusions: MD and atherosclerosis are united by common molecular mechanisms of pathogenesis. Knowledge of MD should be used to argue for a healthy lifestyle as the primary way to prevent atherosclerosis. The development of new approaches to diagnosing and treating MD in atherosclerosis is an urgent task and challenge for modern science.

Association between lipid accumulation product and chronic obstructive pulmonary disease: a cross-sectional study based on U.S. adults

Background

Lipid Accumulation Product (LAP), which is derived from measurements of waist circumference and triglyceride (TG) levels, serves as a comprehensive indicator of lipid accumulation. Emerging research indicates that lipid accumulation dysfunction might significantly contribute to the pathogenesis of Chronic Obstructive Pulmonary Disease (COPD). Nevertheless, the investigation into the association between LAP and COPD risk is still insufficient, particularly in population-based research. This research intends to examine the possible correlation between LAP and the likelihood of developing COPD.

Methods

This study, designed as a cross-sectional analysis, made use of data gathered from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2017 to 2020, encompassing a total of 7,113 eligible participants. LAP, the exposure variable, was calculated using waist circumference and triglyceride concentration. COPD diagnosis was determined using participants' self-reported information. To explore the association between LAP and COPD, multivariate logistic regression models were applied, and smoothing curve fitting was employed to examine any potential nonlinear patterns. Further analysis included stratified subgroup evaluations to assess how variables such as sex, smoking habits, and alcohol intake might impact the relationship between LAP and COPD.

Results

The findings indicated a significant increase in COPD risk with each one-unit rise in ln LAP, as evidenced by an Odds Ratio (OR) of 1.16 [95% Confidence Interval (CI): 1.04-1.30, p < 0.01]. Furthermore, a quartile-based analysis revealed that individuals in the highest ln LAP category had a considerably higher likelihood of developing COPD compared to those in the lowest category, with an OR of 1.35 (95% CI: 1.04-1.75, P for trend <0.01). Furthermore, the smoothing curve fitting identified a nonlinear and positive association between ln LAP and COPD, suggesting a steeper increase in risk as ln LAP values rise. Subgroup analysis suggested that this association remained fairly consistent across various demographic groups.

Conclusion

This study found a significant link between higher LAP levels and an elevated risk of COPD, with the association displaying a nonlinear pattern. As a marker of lipid accumulation abnormalities, LAP may serve as a valuable tool for assessing COPD risk and could inform strategies for early identification and targeted clinical management.

Pharmacological properties of Polygonatum and its active ingredients for the prevention and treatment of cardiovascular diseases

Despite continued advances in prevention and treatment strategies, cardiovascular diseases (CVDs) remain the leading cause of death worldwide, and more effective therapeutic methods are urgently needed. Polygonatum is a traditional Chinese herbal medicine with a variety of pharmacological applications and biological activities, such as antioxidant activity, anti-inflammation, antibacterial effect, immune-enhancing effect, glucose regulation, lipid-lowering and anti-atherosclerotic effects, treatment of diabetes and anticancer effect. There has also been more and more evidence to support the cardioprotective effect of Polygonatum in recent years. However, up to now, there has been a lack of comprehensive studies on the active ingredients and their pharmacotoxicological effects related to cardiovascular diseases. Therefore, the main active components of Polygonatum (including Polysaccharides, Flavonoids, Saponins) and their biological activities were firstly reviewed in this paper. Furthermore, we summarized the pharmacological effects of Polygonatum's active components in preventing and treating CVDs, and its relevant toxicological investigations. Finally, we emphasize the potential of Polygonatum in the prevention and treatment of CVDs.

Immunomodulatory role of mitochondrial DAMPs: a missing link in pathology?

In accordance with the endosymbiotic theory, mitochondrial components bear characteristic prokaryotic signatures, which act as immunomodulatory molecules when released into the extramitochondrial compartment. These endogenous immune triggers, called mitochondrial damage-associated molecular patterns (mtDAMPs), have been implicated in the pathogenesis of various diseases, yet their role remains largely unexplored. In this review, we summarise the available literature on mtDAMPs in diseases, with a special focus on respiratory diseases. We highlight the need to bolster mtDAMP research using a multipronged approach, to study their effect on specific cell types, receptors and machinery in pathologies. We emphasise the lacunae in the current understanding of mtDAMPs, particularly in their cellular release and the chemical modifications they undergo. Finally, we conclude by proposing additional effects of mtDAMPs in diseases, specifically their role in modulating the immune system.

Adverse effect propensity: A new feature of Gulf War illness predicted by environmental exposures

A third of 1990-1 Gulf-deployed personnel developed drug/chemical-induced multisymptom illness, "Gulf War illness" (GWI). Veterans with GWI (VGWI) report increased drug/exposure adverse effects (AEs). Using previously collected data from a case-control study, we evaluated whether the fraction of exposures that engendered AEs ("AE Propensity") is increased in VGWI (it was); whether AE Propensity is related to self-rated "chemical sensitivity" (it did); and whether specific exposures "predicted" AE Propensity (they did). Pesticides and radiation exposure were significant predictors, with copper significantly "protective"-in the total sample (adjusted for GWI-status) and separately in VGWI and controls, on multivariable regression. Mitochondrial impairment and oxidative stress (OS) underlie AEs from many exposures irrespective of nominal specific mechanism. We hypothesize that mitochondrial toxicity and interrelated OS from pesticides and radiation position people on the steep part of the curve of mitochondrial impairment and OS versus symptom/biological disruption, amplifying impact of new exposures. Copper, meanwhile, is involved in critical OS detoxification processes.

Prolonged smoldering Douglas fir smoke inhalation augments respiratory resistances, stiffens the aorta, and curbs ejection fraction in hypercholesterolemic mice

While mounting evidence suggests that wildland fire smoke (WFS) inhalation may increase the burden of cardiopulmonary disease, the occupational risk of repeated exposure during wildland firefighting remains unknown. To address this concern, we evaluated the cardiopulmonary function in mice following a cumulative exposure to lab-scale WFS equivalent to a mid-length wildland firefighter (WLFF) career. Dosimetry analysis indicated that 80 exposure hours at a particulate concentration of 22 mg/m3 yield in mice the same cumulative deposited mass per unit of lung surface area as 3600 h of wildland firefighting. To satisfy this condition, male Apoe-/- mice were whole-body exposed to either air or smoldering Douglas fir smoke (DFS) for 2 h/day, 5 days/week, over 8 consecutive weeks. Particulate size in DFS fell within the respirable range for both mice and humans, with a count median diameter of 110 ± 20 nm. Expiratory breath hold in mice exposed to DFS significantly reduced their minute volume (DFS: 27 ± 4; Air: 122 ± 8 mL/min). By the end of the exposure time frame, mice in the DFS group exhibited a thicker (DFS: 109 ± 3; Air: 98 ± 3 μm) and less distensible (DFS: 23 ± 1; Air: 28 ± 1 MPa-1) aorta with reduced diastolic blood augmentation capacity (DFS: 53 ± 2; Air: 63 ± 2 kPa). Cardiac magnetic resonance imaging further revealed larger end-systolic volume (DFS: 14.6 ± 1.1; Air: 9.9 ± 0.9 μL) and reduced ejection-fraction (DFS: 64.7 ± 1.0; Air: 75.3 ± 0.9 %) in mice exposed to DFS. Consistent with increased airway epithelium thickness (DFS: 10.4 ± 0.8; Air: 7.6 ± 0.3 μm), airway Newtonian resistance was larger following DFS exposure (DFS: 0.23 ± 0.03; Air: 0.20 ± 0.03 cmH2O-s/mL). Furthermore, parenchyma mean linear intercept (DFS: 36.3 ± 0.8; Air: 33.3 ± 0.8 μm) and tissue thickness (DFS: 10.1 ± 0.5; Air: 7.4 ± 0.7 μm) were larger in DFS mice. Collectively, mice exposed to DFS manifested early signs of cardiopulmonary dysfunction aligned with self-reported events in mid-career WLFFs.

Respiratory mechanics following chronic cigarette smoke exposure in the Apoe − / − mouse model

Even though cigarette smoking (CS) has been on the decline over the past 50 years, it is still the leading cause of preventable premature death in the United States. Preclinical models have investigated the cardiopulmonary effects of CS exposure (CSE), but the structure-function relationship in the respiratory system has not yet been fully explored. To evaluate these relationships, we exposed female apolipoprotein E-deficient (Apoe− / − ) mice to mainstream CS (n = 8 ) for 5 days/week over 24 weeks with room air as a control (AE,n = 8 ). To contextualize the impact of CSE, we also assessed the natural aging effects over 24 weeks of air exposure (baseline,n = 8 ). Functional assessments were performed on a small animal mechanical ventilator (flexiVent, SCIREQ), where pressure-volume curves and impedance data at four levels of positive end-expiratory pressure (P peep and with increasing doses of methacholine were collected. Constant phase model parameters (R N : Newtonian resistance, H: coefficient of tissue elastance, and G: coefficient of tissue resistance) were calculated from the impedance data. Perfusion fixed-left lung tissue was utilized for quantification of parenchyma airspace size and tissue thickness, airway wall thickness, and measurements of elastin, cytoplasm + nucleus, fibrin, and collagen content for the parenchyma and airways. Aging caused the lung to become more compliant, with an upward-leftward shift of the pressure-volume curve and a reduction in all constant phase model parameters. This was supported by larger parenchyma airspace sizes, with a reduction in cell cytoplasm + nucleus area. Airway walls became thinner, even though low-density collagen content increased. In contrast, CSE caused a downward-rightward shift of the pressure-volume curve along with an increase in H, G, and hysteresivity (η = G / H ). Organ stiffening was accompanied by enhanced airway hyper-responsiveness following methacholine challenge. Structurally, parenchyma airspaces enlarged, as indicated by an increase in equivalent airspace diameter (D 0 ), and the septum thickened with significant deposition of low-density collagen along with an influx of cells. Airway walls thickened due to deposition of both high and low-density collagen, infiltration of cells, and epithelial cell elongation. In all, our data suggest that CSE in female Apoe− / − mice reduces respiratory functionality and causes morphological alterations in both central and peripheral airways that results in lung stiffening, compared to AE controls.

Mitochondrial reactivity following acute exposure to experimental pain testing in people with HIV and chronic pain

Background: Physical stressors can cause a physiological response that can contribute to an increase in mitochondrial dysfunction and Mitochondrial DNA damage (mtDNA damage). People living with HIV (PWH) are more likely to suffer from chronic pain and may be more susceptible to mitochondrial dysfunction following exposure to a stressor. We used Quantitative Sensory Testing (QST) as an acute painful stressor in order to investigate whether PWH with/without chronic pain show differential mitochondrial physiological responses. Methods: The current study included PWH with (n = 26), and without (n = 29), chronic pain. Participants completed a single session that lasted approximately 180 min, including QST. Blood was taken prior to and following the QST battery for assays measuring mtDNA damage, mtDNA copy number, and mtDNA damage-associated molecular pattern (DAMP) levels (i.e., ND1 and ND6). Results: We examined differences between those with and without pain on various indicators of mitochondrial reactivity following exposure to QST. However, only ND6 and mtDNA damage were shown to be statistically significant between pain groups. Conclusion: PWH with chronic pain showed greater mitochondrial reactivity to laboratory stressors. Consequently, PWH and chronic pain may be more susceptible to conditions in which mitochondrial damage/dysfunction play a central role, such as cognitive decline.

Effects of diet-induced hypercholesterolemia and gold nanoparticles treatment on peripheral tissues

Cholesterol is a lipid molecule of great biological importance to animal cells. Dysregulation of cholesterol metabolism leads to raised blood total cholesterol levels, a clinical condition called hypercholesterolemia. Evidence has shown that hypercholesterolemia is associated with the development of liver and heart disease. One of the mechanisms underlying heart and liver alterations induced by hypercholesterolemia is oxidative stress. In this regard, in several experimental studies, gold nanoparticles (AuNP) displayed antioxidant properties. We hypothesized that hypercholesterolemia causes redox system imbalance in the liver and cardiac tissues, and AuNP treatment could ameliorate it. Young adult male Swiss mice fed a regular rodent diet or a high cholesterol diet for eight weeks and concomitantly treated with AuNP (2.5 μg/kg) or vehicle by oral gavage. Hypercholesterolemia increased the nitrite concentration and glutathione (GSH) levels and decreased the liver's superoxide dismutase (SOD) activity. Also, hypercholesterolemia significantly enhanced the reactive oxygen species (ROS) and GSH levels in cardiac tissue. Notably, AuNP promoted the redox system homeostasis, increasing the SOD activity in hepatic tissue and reducing ROS levels in cardiac tissue. Overall, our data showed that hypercholesterolemia triggered oxidative stress in mice's liver and heart, which was partially prevented by AuNP treatment.

Cardiac Mitochondria Dysfunction in Dyslipidemic Mice

Dyslipidemia triggers many severe pathologies, including atherosclerosis and chronic inflammation. Several lines of evidence, including our studies, have suggested direct effects of dyslipidemia on cardiac energy metabolism, but details of these effects are not clear. This study aimed to investigate how mild dyslipidemia affects cardiac mitochondria function and vascular nucleotide metabolism. The analyses were performed in 3- and 6-month-old knock-out mice for low-density lipoprotein receptor (Ldlr−/−) and compared to wild-type C57Bl/6J mice (WT). Cardiac isolated mitochondria function was analyzed using Seahorse metabolic flux analyzer. The mechanical function of the heart was measured using echocardiography. The levels of fusion, fission, and mitochondrial biogenesis proteins were determined by ELISA kits, while the cardiac intracellular nucleotide concentration and vascular pattern of nucleotide metabolism ecto-enzymes were analyzed using reverse-phase high-performance liquid chromatography. We revealed the downregulation of mitochondrial complex I, together with a decreased activity of citrate synthase (CS), reduced levels of nuclear respiratory factor 1 and mitochondrial fission 1 protein, as well as lower intracellular adenosine and guanosine triphosphates’ pool in the hearts of 6-month Ldlr−/− mice vs. age-matched WT. The analysis of vascular ecto-enzyme pattern revealed decreased rate of extracellular adenosine monophosphate hydrolysis and increased ecto-adenosine deaminase activity (eADA) in 6-month Ldlr−/− vs. WT mice. No changes were observed in echocardiography parameters in both age groups of Ldlr−/− mice. Younger hyperlipidemic mice revealed no differences in cardiac mitochondria function, CS activity, intracellular nucleotides, mitochondrial biogenesis, and dynamics but exhibited minor changes in vascular eADA activity vs. WT. This study revealed that dysfunction of cardiac mitochondria develops during prolonged mild hyperlipidemia at the time point corresponding to the formation of early vascular alterations.

Resistance training prevents damage to the mitochondrial function of the skeletal muscle of rats exposed to secondary cigarette smoke

AIM

To analyze the consumption of oxygen and to quantify the mitochondrial respiratory chain proteins (OXPHOS) in the gastrocnemius muscle of rats exposed to cigarette smoke and/or RT practitioners.

MAIN METHODS

Wistar rats were divided into groups: Control (C), Smoker (S), Exercise (E) and Exercise Smoker (ES). Groups F and ES were exposed to the smoke of 4 cigarettes for 30 min, 2× a day, 5× a week, for 16 weeks. Groups E and ES performed four climbs with progressive load, 1× per day, 5× per week, for 16 weeks. The gastrocnemius muscle was collected for analysis of OXPHOS content and oxygen consumption. Groups S (vs. C) and ES (vs. C and E) showed lower body weight gain when observing the evolution curve.

KEY FINDINGS

The S rats showed a reduction in the NDUFB8 proteins of complex 1, SDHB of complex 2, MTC01 of complex 4 and ATP5A of complex 5 (ATP Synthase) compared to Group C. Additionally, S rats also showed increased consumption of O2 in Basal, Leak, Complex I and I/II combined measures compared to the other groups, suggesting that the activity of the mitochondria of these animals increased in terms of coupling and uncoupling parameters.

SIGNIFICANCE

Our data suggest that exposure to cigarette smoke for 16 weeks is capable of causing impairment of mitochondrial function with reduced expression of respiratory chain proteins in skeletal muscle. However, the RT was effective in preventing impairment of mitochondrial function in the skeletal muscle of rats exposed to secondary cigarette smoke.

Mitochondrial Dysfunction and Cardiovascular Disease: Pathophysiology and Emerging Therapies

Mitochondria ensure the supply of cellular energy through the production of ATP via oxidative phosphorylation. The alteration of this process, called mitochondrial dysfunction, leads to a reduction in ATP and an increase in the production of reactive oxygen species (ROS). Mitochondrial dysfunction can be caused by mitochondrial/nuclear DNA mutations, or it can be secondary to pathological conditions such as cardiovascular disease, aging, and environmental stress. The use of therapies aimed at the prevention/correction of mitochondrial dysfunction, in the context of the specific treatment of cardiovascular diseases, is a topic of growing interest. In this context, the data are conflicting since preclinical studies are numerous, but there are no large randomized studies.

Long term risk of heart failure in individuals with childhood-onset type 1 diabetes

BACKGROUND

We aimed to evaluate the risk of heart failure in young adults with childhood-onset type 1 diabetes from the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study. We also examined risk factors and microvascular disease burden associated with the incidence of heart failure.

METHODS

Participants in the EDC study without known baseline heart failure (n = 655) were enrolled and then followed for 25 years. "Any" heart failure comprised the underlying cause of death, primary reason for hospitalization, EDC clinic examination findings or self-report of a physician diagnosis. "Hard" heart failure was determined only by the underlying cause of death or primary reason for hospitalization. Incidence rates for heart failure were estimated using Poisson models. Cox models were constructed to examine the associations between risk factors and microvascular disease burden with incident heart failure.

RESULTS

The mean baseline age and diabetes duration were 27(8) years and 19 (8) years. Incidence for any and hard heart failure were 3.4 and 1.8/1000 person-years. Diabetes duration, ever smoking and triglycerides were significant risk factors of any heart failure; longer diabetes duration, lower estimated glomerular filtration rate and higher white blood cell count significantly predicted hard heart failure. A gradient association was observed between the number of microvascular disease (from 0 to 3) and "hard" heart failure endpoint but not "any" clinically defined heart failure.

CONCLUSION

Young adults with long-duration type 1 diabetes had a high risk of heart failure. As microvascular disease burden increases so does the risk of heart failure independently of diabetes duration, A1c and coronary artery disease.

Cardiovascular disease and the biology of aging

The incidence and prevalence of a wide range of cardiovascular diseases increases as a function of age. This well-established epidemiological relationship suggests that chronological aging might contribute or increase susceptibility to varied conditions such as atherosclerosis, vascular stiffening or heart failure. Here, we explore the mechanistic links that connect both rare and common cardiovascular conditions to the basic biology of aging. These links provide a rational basis to begin to develop a new set of therapeutics targeting the fundamental mechanisms underlying the aging process and suggest that in the near future, age itself might become a modifiable cardiovascular risk factor.

Acute inhibition of OGA sex-dependently alters the networks associated with bioenergetics, autophagy, and neurodegeneration

The accumulation of neurotoxic proteins characteristic of age-related neurodegenerative pathologies such as Alzheimer's and Parkinson's diseases is associated with the perturbation of metabolism, bioenergetics, and mitochondrial quality control. One approach to exploit these interactions therapeutically is to target the pathways that regulate metabolism. In this respect, the nutrient-sensing hexosamine biosynthesis pathway is of particular interest since it introduces a protein post-translational modification known as O-GlcNAcylation, which modifies different proteins in control versus neurodegenerative disease postmortem brains. A potent inhibitor of the O-GlcNAcase enzyme that removes the modification from proteins, Thiamet G (TG), has been proposed to have potential benefits in Alzheimer's disease. We tested whether key factors in the O-GlcNAcylation are correlated with mitochondrial electron transport and proteins related to the autophagy/lysosomal pathways in the cortex of male and female mice with and without exposure to TG (10 mg/kg i.p.). Mitochondrial complex activities were measured in the protein homogenates, and a panel of metabolic, autophagy/lysosomal proteins and O-GlcNAcylation enzymes were assessed by either enzyme activity assay or by western blot analysis. We found that the networks associated with O-GlcNAcylation enzymes and activities with mitochondrial parameters, autophagy-related proteins as well as neurodegenerative disease-related proteins exhibited sex and TG dependent differences. Taken together, these studies provide a framework of interconnectivity for multiple O-GlcNAc-dependent pathways in mouse brain of relevance to aging and sex/age-dependent neurodegenerative pathogenesis and response to potential therapies.

Secondhand smoke exposure and dyslipidemia among non-smoking adults in the United States

Dyslipidemia is a major public health challenge worldwide and whether secondhand smoke exposure (SHSE) is associated with dyslipidemia is yet to be understood. This study evaluated the relationship between SHSE and odds of dyslipidemia among adults in the United States. We identified 3064 adults who had never smoked in the 2015-2016 National Health and Nutrition Examination Survey and estimated the odds ratio and 95% confidence interval for the relationship between SHSE and odds of dyslipidemia using a multivariable adjusted-logistic regression at a two-sided p < 0.05. Overall, the mean age of respondents was 46.4 ± 18.0 years, 59.6% had dyslipidemia and 36.2% had SHSE. The odds of dyslipidemia among individuals with SHSE were 1.148 (1.147, 1.149) in the overall sample, 1.214 (1.214, 1.215) among women and 1.165 (1.163, 1.167) among men. The odds trended similarly independent of age groups: 1.130 (1.129, 1.131) for young adults (<60 years) and 1.304 (1.300, 1.308) for old adults (≥60 years). SHSE was associated with higher odds of dyslipidemia with higher odds among women and old adults. Primary intervention(s) targeted at reducing SHSE may show benefits in reducing the odds of dyslipidemia, and longitudinal studies would be necessary to clarify the association between SHSE and dyslipidemia.

Novel Insights and Current Evidence for Mechanisms of Atherosclerosis: Mitochondrial Dynamics as a Potential Therapeutic Target

Cardiovascular disease (CVD) is the main cause of death worldwide. Atherosclerosis is the underlying pathological basis of CVD. Mitochondrial homeostasis is maintained through the dynamic processes of fusion and fission. Mitochondria are involved in many cellular processes, such as steroid biosynthesis, calcium homeostasis, immune cell activation, redox signaling, apoptosis, and inflammation, among others. Under stress conditions, mitochondrial dynamics, mitochondrial cristae remodeling, and mitochondrial ROS (mitoROS) production increase, mitochondrial membrane potential (MMP) decreases, calcium homeostasis is imbalanced, and mitochondrial permeability transition pore open (mPTP) and release of mitochondrial DNA (mtDNA) are activated. mtDNA recognized by TLR9 can lead to NF-κB pathway activation and pro-inflammatory factor expression. At the same time, TLR9 can also activate NLRP3 inflammasomes and release interleukin, an event that eventually leads to tissue damage and inflammatory responses. In addition, mitochondrial dysfunction may amplify the activation of NLRP3 through the production of mitochondrial ROS, which together aggravate accumulating mitochondrial damage. In addition, mtDNA defects or gene mutation can lead to mitochondrial oxidative stress. Finally, obesity, diabetes, hypertension and aging are risk factors for the progression of CVD, which are closely related to mitochondrial dynamics. Mitochondrial dynamics may represent a new target in the treatment of atherosclerosis. Antioxidants, mitochondrial inhibitors, and various new therapies to correct mitochondrial dysfunction represent a few directions for future research on therapeutic intervention and amelioration of atherosclerosis.

The Beneficial Effects of Saffron Extract on Potential Oxidative Stress in Cardiovascular Diseases

Saffron is commonly used in traditional medicines and precious perfumes. It contains pharmacologically active compounds with notably potent antioxidant activity. Saffron has a variety of active components, including crocin, crocetin, and safranal. Oxidative stress plays an important role in many cardiovascular diseases, and its uncontrolled chain reaction is related to myocardial injury. Numerous studies have confirmed that saffron exact exhibits protective effects on the myocardium and might be beneficial in the treatment of cardiovascular disease. In view of the role of oxidative stress in cardiovascular disease, people have shown considerable interest in the potential role of saffron extract as a treatment for a range of cardiovascular diseases. This review analyzed the use of saffron in the treatment of cardiovascular diseases through antioxidant stress from four aspects: antiatherosclerosis, antimyocardial ischemia, anti-ischemia reperfusion injury, and improvement in drug-induced cardiotoxicity, particularly anthracycline-induced. Although data is limited in humans with only two clinically relevant studies, the results of preclinical studies regarding the antioxidant stress effects of saffron are promising and warrant further research in clinical trials. This review summarized the protective effect of saffron in cardiovascular diseases and drug-induced cardiotoxicity. It will facilitate pharmacological research and development and promote utilization of saffron.

Treatment Strategies Against Diabetic Foot Ulcer: Success so Far and the Road Ahead

BACKGROUND

Diabetic foot ulcer (DFU) is one of the leading complications of type-2 diabetes mellitus. It is associated with neuropathy and peripheral arterial disease of the lower limb in patients with diabetes. There are four stages of wound healing, namely hemostasis phase, inflammatory phase, proliferative phase and maturation phase. In the case of DFU, all these stages are disturbed which lead to delay in healing and consequently to lower limb amputation. Conventional dosage forms like tablets, creams, ointments, gels and capsules have been used for the treatment of diabetic foot ulcer for many years.

INTRODUCTION

In this review, the global prevalence as well as etiopathogenesis related to diabetic foot ulcer have been discussed. The potential role of various synthetic and herbal drugs, as well as their conventional dosage forms in the effective management of DFU have been discussed in detail.

METHODS

Structured search of bibliographic databases from previously published peer-reviewed research papers was explored and data has been represented in terms of various approaches that are used for the treatment of DFU.

RESULTS

About 148 papers, including both research and review articles, were included in this review to produce a comprehensive as well as a readily understandable article. A series of herbal and synthetic drugs have been discussed along with their current status of treatment in terms of dose and mechanism of action.

CONCLUSION

DFU has become one of the most common complications in patients having diabetes for more than ten years. Hence, understanding the root cause and its successful treatment is a big challenge because it depends upon multiple factors such as the judicious selection of drugs as well as proper control of blood sugar level. Most of the drugs that have been used so far either belong to the category of antibiotics, antihyperglycaemic or they have been repositioned. In clinical practice, much focus has been given to dressings that have been used to cover the ulcer. The complete treatment of DFU is still a farfetched dream to be achieved and it is expected that combination therapy of herbal and synthetic drugs with multiple treatment pathways could be able to offer better management of DFU.

Resveratrol and exercise combined to treat functional limitations in late life: A pilot randomized controlled trial

PURPOSE

To evaluate the safety and feasibility of combining exercise (EX) and resveratrol to treat older adults with physical function limitations.

METHODS

Three-arm, two-site pilot randomized, controlled trial (RCT) for community-dwelling adults (N = 60), 71.8 ± 6.3 years of age with functional limitations. Participants were randomized to receive either 12 weeks of (1) EX + placebo [EX0], (2) EX + 500 mg/day resveratrol [EX500], or (3) EX + 1000 mg/day resveratrol [EX1000]. EX consisted of two sessions a week for 12 weeks of center-based walking and whole-body resistance training. Safety was assessed through adverse events and feasibility through exercise session and supplement (placebo, or resveratrol) protocol adherence. Outcome measures included a battery of indices of physical function as well as skeletal muscle mitchondrial function. Data were adjusted for age and gender using the Intent-To-Treat approach.

RESULTS

Adverse event frequency and type were similar between groups (n = 8 EX0, n = 12 EX500, and n = 7 EX1000). Overall, 85% of participants met the supplement adherence via pill counts while 82% met the exercise session adherence. Adjusted within group mean differences (95% confidence interval) from week 0 to 12 for gait speed ranged from -0.04 (EX0: -0.1, 0.03) m/s to 0.04 (EX1000: -0.02, 0.11) and the six-minute walk test mean differences were 9.45 (EX0: -9.02, 27.7), 22.9 (EX500: 4.18, 41.6), and 33.1 (EX1000: 13.8, 52.4) meters. Unadjusted mean differences for citrate synthase were -0.80 (EX0: -15.45, 13.84), -1.38 (EX500: -12.16, 9.39), and 7.75 (EX1000: -4.68, 20.18) mU/mg. COX activity mean within group changes ranged from -0.05 (EX0) to 0.06 (EX500) k/s/mg. Additional outcomes are detailed in the text.

CONCLUSION

The pilot RCT indicated that combined EX + resveratrol was safe and feasible for older adults with functional limitations and may improve skeletal muscle mitochondrial function and mobility-related indices of physical function. A larger trial appears warranted and is needed to formally test these hypotheses.

Environmental stress influences mitochondrial metabolism in vascular cells: consequences for angiogenesis

While the important and varied roles that vascular cells play in both health and disease is well recognised, the focus on potential therapeutic targets continually shifts as new players emerge. Here, we outline how mitochondria may be viewed as more than simply energy-generating organelles, but instead as important sentinels of metabolic health and effectors of appropriate responses to physiological challenges.

The Role of Mitochondria in Cardiovascular Diseases

The role of mitochondria in cardiovascular diseases is receiving ever growing attention. As a central player in the regulation of cellular metabolism and a powerful controller of cellular fate, mitochondria appear to comprise an interesting potential therapeutic target. With the development of DNA sequencing methods, mutations in mitochondrial DNA (mtDNA) became a subject of intensive study, since many directly lead to mitochondrial dysfunction, oxidative stress, deficient energy production and, as a result, cell dysfunction and death. Many mtDNA mutations were found to be associated with chronic human diseases, including cardiovascular disorders. In particular, 17 mtDNA mutations were reported to be associated with ischemic heart disease in humans. In this review, we discuss the involvement of mitochondrial dysfunction in the pathogenesis of atherosclerosis and describe the mtDNA mutations identified so far that are associated with atherosclerosis and its risk factors.

The molecular biomarkers of vascular aging and atherosclerosis: telomere length and mitochondrial DNA4977 common deletion

Age is the dominant risk factor for the most prevalent atherosclerotic vascular diseases, including coronary artery disease, myocardial infarction, cerebrovascular disease and stroke. In human, telomere erosion and mitochondrial DNA (mtDNA) damage play a central role in the mechanisms leading to cellular aging decline. This review summarizes the most relevant findings on the role of telomere shortening and the common mtDNA⁴⁹⁷⁷ deletion in the progression and evolution of atherosclerosis by combining insight from experimental models and human clinical studies. The current evidence shows a link between telomere erosion and compromised mitochondrial function and provides a new perspective regarding their potential role as clinical biomarkers and therapeutic targets.

Nicotine in Senescence and Atherosclerosis

Cigarette smoke is a known exacerbator of age-related pathologies, such as cardiovascular disease (CVD), atherosclerosis, and cellular aging (senescence). However, the role of nicotine and its major metabolite cotinine is yet to be elucidated. Considering the growing amount of nicotine-containing aerosol use in recent years, the role of nicotine is a relevant public health concern. A number of recent studies and health education sites have focused on nicotine aerosol-induced adverse lung function, and neglected cardiovascular (CV) impairments and diseases. A critical review of the present scientific literature leads to the hypothesis that nicotine mediates the effects of cigarette smoke in the CV system by increasing MAPK signaling, inflammation, and oxidative stress through NADPH oxidase 1 (Nox1), to induce vascular smooth muscle cell (VSMC) senescence. The accumulation of senescent VSMCs in the lesion cap is detrimental as it increases the pathogenesis of atherosclerosis by promoting an unstable plaque phenotype. Therefore, nicotine, and most likely its metabolite cotinine, adversely influence atherosclerosis.

Passive smoking acutely affects the microcirculation in healthy non-smokers

OBJECTIVE

Acute effects of passive smoking on microcirculation have not been sufficiently studied. The aim of the present study was to detect microcirculatory alterations in healthy non-smokers after passive exposure to cigarette smoke, utilizing the Near Infrared Spectroscopy method combined with the vascular occlusion technique.

METHODS

Sixteen (9 females, age: 34 ± 9 years) non-smoking, healthy volunteers were exposed to passive smoking for 30 min in a temperature-controlled environment. Smoke concentration was monitored with a real-time particle counter. The following microcirculatory parameters were estimated: baseline tissue oxygen saturation (StO2); StO2 decrement after vascular occlusion (indicating the oxygen consumption rate); StO2incremental response after vascular occlusion release (reperfusion rate); the time period where the StO2 signal returns to the baseline values after the hyperemic response.

RESULTS

Baseline StO2 (79.6 ± 6.4 vs. 79 ± 8%, p = 0.53) as well as the time needed for StO2 to return to baseline levels (138.2 ± 26.5 vs. 142.1 ± 34.6 s, p = 0.64) did not significantly differ before vs. after passive smoking exposure. Oxygen consumption rate decreased after 30 min exposure to passive smoking (from 12.8 ± 4.2 to 11.3 ± 2.8%/min, p = 0.04); Reperfusion rate also significantly decreased (from 5.6 ± 1.8 to 5 ± 1.7%/s, p = 0.04).

CONCLUSIONS

Our results suggest that acute exposure to passive smoking delays peripheral tissue oxygen consumption and adversely affects microcirculatory responsiveness after stagnant ischemia in healthy non-smokers.

Adrenal βarrestin1 targeting for tobacco-associated cardiac dysfunction treatment: Aldosterone production as the mechanistic link

Tobacco kills 6 million people annually and its global health costs are continuously rising. The main addictive component of every tobacco product is nicotine. Among the mechanisms by which nicotine, and its major metabolite, cotinine, contribute to heart disease is the renin-angiotensin-aldosterone system (RAAS) activation. This increases aldosterone production from the adrenals and circulating aldosterone levels. Aldosterone is a mineralocorticoid hormone with various direct harmful effects on the myocardium, including increased reactive oxygen species (ROS) generation, which contributes significantly to cardiac mitochondrial dysfunction and cardiac aging. Aldosterone is produced in the adrenocortical zona glomerulosa (AZG) cells in response to angiotensin II (AngII), activating its type 1 receptor (AT1R). The AT1R is a G protein-coupled receptor (GPCR) that leads to aldosterone biosynthesis and secretion, via signaling from both Gq/11 proteins and the GPCR adapter protein βarrestin1, in AZG cells. Adrenal βarrestin1 is essential for AngII-dependent adrenal aldosterone production, which aggravates heart disease. Since adrenal βarrestin1 is essential for raising circulating aldosterone in the body and tobacco compounds are also known to elevate aldosterone levels in smokers, accelerating heart disease progression, our central hypothesis is that nicotine and cotinine increase aldosterone levels to induce cardiac injury by stimulating adrenal βarrestin1. In the present review, we provide an overview of the current literature of the physiology and pharmacology of adrenal aldosterone production regulation, of the effects of tobacco on this process and, finally, of the effects of tobacco and aldosterone on cardiac structure and function, with a particular focus on cardiac mitochondrial function. We conclude our literature account with a brief experimental outline, as well as with some therapeutic perspectives of our pharmacological hypothesis, that is that adrenal βarrestin1 is a novel molecular target for preventing tobacco-induced hyperaldosteronism, thereby also ameliorating tobacco-related heart disease development.

Mitochondrial targeted peptides preserve mitochondrial organization and decrease reversible myocardial changes in early swine metabolic syndrome

Aims

The mechanisms responsible for cardiac damage in the early stages of metabolic syndrome (MetS) remain unknown. Mitochondria are intimately associated with cellular myofibrils, with the cytoskeleton functioning as a linkage coordinator, and closely associated to the calcium release sites of the sarcoplasmic reticulum (SR). We hypothesized that early MetS is characterized by mitochondria-related myocardial damage, associated with altered cytoskeletal-mitochondria-SR interaction.

Methods and results

Domestic pigs were studied after 16 weeks of diet-induced MetS, MetS treated for the last 4 weeks with the mitochondrial-targeted peptide elamipretide (ELAM; 0.1 mg/kg SC q.d), or Lean controls (n = 6/group). Cardiac remodeling and function were assessed by fast comuted tomography. Myocardial mitochondrial structure, SR-mitochondria interaction, calcium handling, cytoskeletal proteins, oxidative stress, and apoptosis were studied ex-vivo. MetS pigs developed hyperlipidemia, hypertension, and insulin resistance, yet cardiac function was preserved. MetS-induced mitochondrial disorganization, decreased (C18:2)4 cardiolipin, disrupted ATP/ADP balance, and decreased cytochrome-c oxidase (COX)-IV activity. MetS also increased mitochondrial hydrogen peroxide (H2O2) production, decreased nicotinamide adenine dinucleotide phosphate (NADPH)/NADP and GSH/GSSG, and decreased myocardial desmin and β2 tubulin immunoreactivity, and impaired SR-mitochondrial interaction and mitochondrial calcium handling, eliciting myocardial oxidative stress and apoptosis. ELAM improved mitochondrial organization and cardiolipin species profile, restored ATP/ADP ratio and COX-IV activity, decreased H202 production, and improved generation of NADPH and GSH. ELAM also improved cytoskeletal-mitochondria-SR interaction and mitochondrial calcium handling, attenuating oxidative stress, and apoptosis.

Conclusions

Disorganization of cardiomyocyte cytoskeletal-mitochondria-SR network is associated with cardiac reversible changes in early MetS, preceding overt cardiac dysfunction. These findings may introduce novel therapeutic targets for blunting cardiac damage in early MetS.

Acute increases in O-GlcNAc indirectly impair mitochondrial bioenergetics through dysregulation of LonP1-mediated mitochondrial protein complex turnover

The attachment of O-linked β-N-acetylglucosamine (O-GlcNAc) to the serine and threonine residues of proteins in distinct cellular compartments is increasingly recognized as an important mechanism regulating cellular function. Importantly, the O-GlcNAc modification of mitochondrial proteins has been identified as a potential mechanism to modulate metabolism under stress with both potentially beneficial and detrimental effects. This suggests that temporal and dose-dependent changes in O-GlcNAcylation may have different effects on mitochondrial function. In the current study, we found that acutely augmenting O-GlcNAc levels by inhibiting O-GlcNAcase with Thiamet-G for up to 6 h resulted in a time-dependent decrease in cellular bioenergetics and decreased mitochondrial complex I, II, and IV activities. Under these conditions, mitochondrial number was unchanged, whereas an increase in the protein levels of the subunits of several electron transport complex proteins was observed. However, the observed bioenergetic changes appeared not to be due to direct increased O-GlcNAc modification of complex subunit proteins. Increases in O-GlcNAc were also associated with an accumulation of mitochondrial ubiquitinated proteins; phosphatase and tensin homolog induced kinase 1 (PINK1) and p62 protein levels were also significantly increased. Interestingly, the increase in O-GlcNAc levels was associated with a decrease in the protein levels of the mitochondrial Lon protease homolog 1 (LonP1), which is known to target complex IV subunits and PINK1, in addition to other mitochondrial proteins. These data suggest that impaired bioenergetics associated with short-term increases in O-GlcNAc levels could be due to impaired, LonP1-dependent, mitochondrial complex protein turnover.

Mitochondrial Oxidative Phosphorylation defect in the Heart of Subjects with Coronary Artery Disease

Coronary artery disease (CAD) is a leading cause of death worldwide and frequently associated with mitochondrial dysfunction. Detailed understanding of abnormalities in mitochondrial function that occur in patients with CAD is lacking. We evaluated mitochondrial damage, energy production, and mitochondrial complex activity in human non-CAD and CAD hearts. Fresh and frozen human heart tissue was used. Cell lysate or mitochondria were isolated using standard techniques. Mitochondrial DNA (_mtDNA), NAD + and ATP levels, and mitochondrial oxidative phosphorylation capacity were evaluated. Proteins critical to the regulation of mitochondrial metabolism and function were also evaluated in tissue lysates. PCR analysis revealed an increase in _mtDNA lesions and the frequency of mitochondrial common deletion, both established markers for impaired mitochondrial integrity in CAD compared to non-CAD patient samples. NAD⁺ and ATP levels were significantly decreased in CAD subjects compared to Non-CAD (NAD⁺ fold change: non-CAD 1.00 ± 0.17 vs. CAD 0.32 ± 0.12* and ATP fold change: non-CAD 1.00 ± 0.294 vs. CAD 0.01 ± 0.001*; N = 15, P < 0.005). We observed decreased respiration control index in CAD tissue and decreased activity of complexes I, II, and III. Expression of ETC complex subunits and respirasome formation were increased; however, elevations in the de-active form of complex I were observed in CAD. We observed a corresponding increase in glycolytic flux, indicated by a rise in pyruvate kinase and lactate dehydrogenase activity, indicating a compensatory increase in glycolysis for cellular energetics. Together, these results indicate a shift in mitochondrial metabolism from oxidative phosphorylation to glycolysis in human hearts subjects with CAD.

Review of the role of cigarette smoking in diabetic foot

Diabetic foot ulceration has been a serious issue over the past decades in Asia, causing economic and social problems. Therefore, it is important to identify and reduce the risk factors of diabetic foot. Cigarette smoking has been reported to be associated with diabetes and its macrovascular complications, but the relationship between smoking and diabetic foot ulcers is still unclear. In the present review, we summarize the effects of cigarette smoking on diabetic foot ulcers with respect to peripheral neuropathy, vascular alterations and wound healing. One underlying mechanism of these impacts might be the smoking-induced oxidative stress inside the cells. At the end of this review, the current mainstream therapies for smoking cessation are also outlined. We believe that it is urgent for all diabetic patients to quit smoking so as to reduce their chances of developing foot ulcers and to improve the prognosis of diabetic foot ulcers.

Environmental Tobacco Smoke and Cardiovascular Disease

Environmental tobacco smoke (ETS) and its sequelae are among the largest economic and healthcare burdens in the United States and worldwide. The relationship between active smoking and atherosclerosis is well-described in the literature. However, the specific mechanisms by which ETS influences atherosclerosis are incompletely understood. In this paper, we highlight the definition and chemical constituents of ETS, review the existing literature outlining the effects of ETS on atherogenesis and thrombosis in both animal and human models, and briefly outline the public health implications of ETS based on these data.

The effects of coenzyme Q10 supplementation on lipid profiles among patients with coronary artery disease: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Chronic inflammation and increased oxidative stress significantly contribute in developing coronary artery disease (CAD). Hence, antioxidant supplementation might be an appropriate approach to decrease the incidence of CAD. This systematic review and meta-analysis was aimed to determine the effects of coenzyme Q10 (CoQ10) supplementation on lipid profile, as one of the major triggers for CAD, among patients diagnosed with coronary artery disease.

METHODS

EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science were searched for studies prior to May 20th, 2018. Cochrane Collaboration risk of bias tool was applied to assess the methodological quality of included trials. I-square and Q-tests were used to measure the existing heterogeneity across included studies. Considering heterogeneity among studies, fixed- or random-effect models were applied to pool standardized mean differences (SMD) as overall effect size.

RESULTS

A total of eight trials (267 participants in the intervention group and 259 in placebo group) were included in the current meta-analysis. The findings showed that taking CoQ10 by patients with CAD significantly decreased total-cholesterol (SMD -1.07; 95% CI, - 1.94, - 0.21, P = 0.01) and increased HDL-cholesterol levels (SMD 1.30; 95% CI, 0.20, 2.41, P = 0.02). We found no significant effects of CoQ10 supplementation on LDL-cholesterol (SMD -0.37; 95% CI, - 0.87, 0.13, P = 0.14), lipoprotein (a) [Lp(a)] levels (SMD -1.12; 95% CI, - 2.84, 0.61, P = 0.20) and triglycerides levels (SMD 0.01; 95% CI, - 0.22, 0.24, P = 0.94).

CONCLUSIONS

This meta-analysis demonstrated the promising effects of CoQ10 supplementation on lowering lipid levels among patients with CAD, though it did not affect triglycerides, LDL-cholesterol and Lp(a) levels.

Oxidative burden in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high serum levels of low-density lipoprotein cholesterol (LDL-c). FH is characterized by accelerated development of atherosclerosis and represents the most frequent hereditary cause of premature coronary heart disease. Mutations of the LDL receptor gene are the genetic signature of FH, resulting in abnormal levels of circulating LDLs. Moreover, FH promotes the generation of reactive oxygen species (ROS) which is another key mechanism involved in atherosclerosis development and progression. The aim of this narrative review is to update the current knowledge on the pathophysiological mechanisms linking FH to ROS generation and their detrimental impact on atherosclerotic pathophysiology. With this purpose, we reviewed experimental and clinical data on the association between FH and OS and the functional role of OS as a promoter of inflammation and atherosclerosis. In this regard, oxidant species such as oxidized LDL, malondialdehyde, ROS, and isoprostanes emerged as leading mediators of the oxidative injury in FH. In conclusion, targeting oxidative stress may be a promising therapeutic strategy to reduce atherogenesis in patients with FH.

Methods for assessing mitochondrial quality control mechanisms and cellular consequences in cell culture

Mitochondrial quality is under surveillance by autophagy, the cell recycling process which degrades and removes damaged mitochondria. Inadequate autophagy results in deterioration in mitochondrial quality, bioenergetic dysfunction, and metabolic stress. Here we describe in an integrated work-flow to assess parameters of mitochondrial morphology, function, mtDNA and protein damage, metabolism and autophagy regulation to provide the framework for a practical assessment of mitochondrial quality. This protocol has been tested with cell cultures, is highly reproducible, and is adaptable to studies when cell numbers are limited, and thus will be of interest to researchers studying diverse physiological and pathological phenomena in which decreased mitochondrial quality is a contributory factor.

Placental mitochondrial biogenesis and function was slightly changed by gestational hypercholesterolemia in full-term pregnant women

It was reported that high blood cholesterol levels increased the susceptibility to mitochondrial dysfunction. This study hypothesized that the gestational hypercholesterolemia (HC) could induce the mitochondrial dysfunction in term human placenta. The eligible pregnant women were recruited from Xuanwu Hospital in Beijing during their first prenatal visit (before their 10th week of pregnancy). In total, 19 pregnant women whose serum total cholesterol levels were higher than 7.25 mm at third trimester (measured at 36–38 weeks) were selected as gestational HC. Other 19 pregnant women with normal cholesterol level matched with age, pre-gestational body mass index, and the neonatal gender were included as the control group. Full-term placenta samples were collected. The mitochondrial DNA (mtDNA) copy number, messenger RNA (mRNA) expression of cytochrome c oxidase subunit I, adenosine triphosphate monophosphatase 6 (ATP6ase), citrate synthase, peroxisome proliferator-activated receptor-γ (PPARγ) co-activator 1α, PPARγ co-activator 1β and estrogen-related receptor-α, and the activity of mitochondrial respiratory chain enzyme complex were measured. Pregnancy outcomes were obtained by extraction from medical records and the labor ward register. The results showed that only placental mtDNA copy number and mRNA expression of ATP6ase were significantly decreased in HC group. No significant differences were detected of other measurements between the two groups. These findings indicated that gestational HC might not induce the damage of placental function seriously.

Detection of mitochondrial DNA with 4977 bp deletion in leukocytes of patients with ischemic stroke

BACKGROUND

Coronary artery disease is associated with a common mitochondrial DNA alteration, a 4977 bp deletion (mtDNA4977). The role of mtDNA4977 in ischemic stroke is unknown.

METHODS

Real-time quantitative PCR was performed to quantify total mtDNA and mtDNA4977 in leukocytes in 283 ischemic stroke cases and 135 controls. Ratios of mtDNA4977 to total-mtDNA and total-mtDNA to nuclear-DNA were calculated. Nested PCR and Sanger sequencing were used to confirm undetectable levels of mtDNA4977.

RESULTS

For 191 patients and 74 control subjects in the male group and 92 patients and 61 control subjects in the female group, there were no significant between-group differences in age, cholesterol level, body mass index, stroke severity, or 4977 deletion. After adjusting for confounding factors, there was no correlation between mtDNA4977 amount and infarction risk, recurrent stroke, or stroke severity. However, mtDNA4977 was undetected in 6.94% subjects, and these individuals had a higher prevalence of stroke than those with detectable mtDNA4977 (OR: 0.181, 95% CI 0.041-0.798, p = 0.024). Additionally, mtDNA4977 status had no effect on stroke prognosis, including stroke severity and recurrent stroke.

CONCLUSION

In conclusion, there was no apparent association between mtDNA4977 deletion and cerebral infarction. Undetectable mtDNA4977 may be a marker or risk factor for ischemic stroke.

Minimising failure in critical lower limb ischaemia intervention: Adjuvant capillary bed recruitment is the missed opportunity

Critical limb ischaemia is the end stage of peripheral arterial disease before limb loss. Contemporary interventions to restore blood flow have high morbidity and mortality and fail to provide sustained restoration of peripheral circulation. Cell-based therapies designed to promote neovascularisation or angiogenesis have been shown in trials to be safe but clinically ineffective. Notwithstanding endless research in the area, no headway has been made in identifying a successful therapy designed specifically to target muscle disease in critical lower limb ischaemia. Thus, the quest to find an effective, lasting solution for critical lower limb ischaemia continues and requires more innovative therapeutic tactics. Our aim is to highlight the crucially interlinked role of the capillary bed, skeletal muscle mass and mitochondria in critical lower limb ischaemia patients and to identify novel therapeutic mechanisms that the vascular interventionalist can add to their armamentarium.

Air Pollution Stress and the Aging Phenotype: The Telomere Connection

Aging is a complex physiological phenomenon. The question why some subjects grow old while remaining free from disease whereas others prematurely die remains largely unanswered. We focus here on the role of air pollution in biological aging. Hallmarks of aging can be grouped into three main categories: genomic instability, telomere attrition, and epigenetic alterations leading to altered mitochondrial function and cellular senescence. At birth, the initial telomere length of a person is largely determined by environmental factors. Telomere length shortens with each cell division and exposure to air pollution as well as low residential greens space exposure is associated with shorter telomere length. Recent studies show that the estimated effects of particulate air pollution exposure on the telomere mitochondrial axis of aging may play an important role in chronic health effects of air pollution. The exposome encompasses all exposures over an entire life. As telomeres can be considered as the cellular memories of exposure to oxidative stress and inflammation, telomere maintenance may be a proxy for assessing the "exposome". If telomeres are causally related to the aging phenotype and environmental air pollution is an important determinant of telomere length, this might provide new avenues for future preventive strategies.

Human Mn-superoxide dismutase inactivation by peroxynitrite: a paradigm of metal-catalyzed tyrosine nitration in vitro and in vivo

Nitration of human MnSOD at active site Tyr34 represents a biologically-relevant oxidative post-translational modification that causes enzyme inactivation.

Small Molecule Mediated Restoration of Mitochondrial Function Augments Anti-Mycobacterial Activity of Human Macrophages Subjected to Cholesterol Induced Asymptomatic Dyslipidemia

Mycobacterium tuberculosis (M.tb) infection manifests into tuberculosis (TB) in a small fraction of the infected population that comprises the TB susceptible group. Identifying the factors potentiating susceptibility to TB persistence is one of the prime agenda of TB control programs. Recently, WHO recognized diabetes as a risk factor for TB disease progression. The closely related pathological state of metabolic imbalance, dyslipidemia, is yet another emerging risk factor involving deregulation in host immune responses. While high cholesterol levels are clinically proven condition for perturbations in cardiac health, a significant fraction of population these days suffer from borderline risk cholesterol profiles. This apparently healthy population is susceptible to various health risks placing them in the "pre-disease" range. Our study focuses on determining the role of such asymptomatic dyslipidemia as a potential risk factor for susceptibility to TB persistence. Macrophages exposed to sub-pathological levels of cholesterol for chronic period, besides impaired release of TNF-α, could not clear intracellular pathogenic mycobacteria effectively as compared to the unexposed cells. These cells also allowed persistence of opportunistic mycobacterial infection by M. avium and M. bovis BCG, indicating highly compromised immune response. The cholesterol-treated macrophages developed a foamy phenotype with a significant increase in intracellular lipid-bodies prior to M.tb infection, potentially contributing to pre-disease state for tuberculosis infection. The foamy phenotype, known to support M.tb infection, increased several fold upon infection in these cells. Additionally, mitochondrial morphology and function were perturbed, more so during infection in cholesterol treated cells. Pharmacological supplementation with small molecule M1 that restored mitochondrial structural and functional integrity limited M.tb survival more effectively in cholesterol exposed macrophages. Mechanistically, M1 molecule promoted clearance of mycobacteria by reducing total cellular lipid content and restoring mitochondrial morphology and function to its steady state. We further supported our observations by infection assays in PBMC-derived macrophages from clinically healthy volunteers with borderline risk cholesterol profiles. With these observations, we propose that prolonged exposure to sub-pathological cholesterol can lead to asymptomatic susceptibility to M.tb persistence. Use of small molecules like M1 sets yet another strategy for host-directed therapy where re-functioning of mitochondria in cholesterol abused macrophages can improve M.tb clearance.

Functional, Cellular, and Molecular Remodeling of the Heart under Influence of Oxidative Cigarette Tobacco Smoke

Passive and active chronic cigarette smoking (CS) remains an international epidemic and a key risk factor for cardiovascular disease (CVD) development. CS-induced cardiac damage is divided into two major and interchangeable mechanisms: (1) direct adverse effects on the myocardium causing smoking cardiomyopathy and (2) indirect effects on the myocardium by fueling comorbidities such as atherosclerotic syndromes and hypertension that eventually damage and remodel the heart. To date, our understanding of cardiac remodeling following acute and chronic smoking exposure is not well elucidated. This manuscript presents for the first time the RIMD (oxidative stress (R), inflammation (I), metabolic impairment (M), and cell death (D)) detrimental cycle concept as a major player in CS-induced CVD risks and direct cardiac injury. Breakthroughs and latest findings in the field with respect to structural, functional, cellular, and molecular cardiac remodeling following chronic smoking exposure are summarized. This review also touches the genetics/epigenetics of smoking as well as the smoker's paradox and highlights the most currently prominent pharmacological venues to mitigate CS-induced adverse cardiac remodeling.

O-GlcNAc regulation of autophagy and α-synuclein homeostasis; implications for Parkinson's disease

Post-translational modification on protein Ser/Thr residues by O-linked attachment of ß-N-acetyl-glucosamine (O-GlcNAcylation) is a key mechanism integrating redox signaling, metabolism and stress responses. One of the most common neurodegenerative diseases that exhibit aberrant redox signaling, metabolism and stress response is Parkinson’s disease, suggesting a potential role for O-GlcNAcylation in its pathology. To determine whether abnormal O-GlcNAcylation occurs in Parkinson’s disease, we analyzed lysates from the postmortem temporal cortex of Parkinson’s disease patients and compared them to age matched controls and found increased protein O-GlcNAcylation levels. To determine whether increased O-GlcNAcylation affects neuronal function and survival, we exposed rat primary cortical neurons to thiamet G, a highly selective inhibitor of the enzyme which removes the O-GlcNAc modification from target proteins, O-GlcNAcase (OGA). We found that inhibition of OGA by thiamet G at nanomolar concentrations significantly increased protein O-GlcNAcylation, activated MTOR, decreased autophagic flux, and increased α-synuclein accumulation, while sparing proteasomal activities. Inhibition of MTOR by rapamycin decreased basal levels of protein O-GlcNAcylation, decreased AKT activation and partially reversed the effect of thiamet G on α-synuclein monomer accumulation. Taken together we have provided evidence that excessive O-GlcNAcylation is detrimental to neurons by inhibition of autophagy and by increasing α-synuclein accumulation.

Inhibition of autophagy with bafilomycin and chloroquine decreases mitochondrial quality and bioenergetic function in primary neurons

Autophagy is an important cell recycling program responsible for the clearance of damaged or long-lived proteins and organelles. Pharmacological modulators of this pathway have been extensively utilized in a wide range of basic research and pre-clinical studies. Bafilomycin A1 and chloroquine are commonly used compounds that inhibit autophagy by targeting the lysosomes but through distinct mechanisms. Since it is now clear that mitochondrial quality control, particularly in neurons, is dependent on autophagy, it is important to determine whether these compounds modify cellular bioenergetics. To address this, we cultured primary rat cortical neurons from E18 embryos and used the Seahorse XF96 analyzer and a targeted metabolomics approach to measure the effects of bafilomycin A1 and chloroquine on bioenergetics and metabolism. We found that both bafilomycin and chloroquine could significantly increase the autophagosome marker LC3-II and inhibit key parameters of mitochondrial function, and increase mtDNA damage. Furthermore, we observed significant alterations in TCA cycle intermediates, particularly those downstream of citrate synthase and those linked to glutaminolysis. Taken together, these data demonstrate a significant impact of bafilomycin and chloroquine on cellular bioenergetics and metabolism consistent with decreased mitochondrial quality associated with inhibition of autophagy.

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Autophagy inhibition decreased mitochondrial bioenergetics in intact neurons.

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Autophagy inhibition decreased mitochondrial complexes I, II or IV substrate linked respiration.

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Autophagy inhibition increased mitochondrial DNA damage.

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Autophagy inhibition decreased major components of the Krebs cycle.

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Autophagy inhibition resulted in decreased citrate synthase activities.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association

BACKGROUND

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation.

PURPOSE

The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined.

CONCLUSIONS

The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children.

IMPLICATIONS

Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

The Apoe(-/-) mouse model: a suitable model to study cardiovascular and respiratory diseases in the context of cigarette smoke exposure and harm reduction

Atherosclerosis-prone apolipoprotein E-deficient (Apoe(-/-)) mice display poor lipoprotein clearance with subsequent accumulation of cholesterol ester-enriched particles in the blood, which promote the development of atherosclerotic plaques. Therefore, the Apoe(-/-) mouse model is well established for the study of human atherosclerosis. The systemic proinflammatory status of Apoe(-/-) mice also makes them good candidates for studying chronic obstructive pulmonary disease, characterized by pulmonary inflammation, airway obstruction, and emphysema, and which shares several risk factors with cardiovascular diseases, including smoking. Herein, we review the results from published studies using Apoe(-/-) mice, with a particular focus on work conducted in the context of cigarette smoke inhalation studies. The findings from these studies highlight the suitability of this animal model for researching the effects of cigarette smoking on atherosclerosis and emphysema.

The influence of smoking on radiation-induced bystander signal production in esophageal cancer patients

The relevance of radiation-induced bystander effects in humans is unclear. Much of the existing data relate to cell lines but the effect of bystander signals in complex human tissues is unclear. A phase II clinical study was untaken, where blood sera from 60 patients along with 15 cancer-free volunteers were used to detect whether measurable bystander factor(s) could be found in the blood following high dose rate (HDR) brachytherapy. Overall, there was no significant change in bystander signal production (measured in a human keratinocyte reporter system) before and after one treatment fraction of HDR brachytherapy (p>0.05). Further assessment of patient characteristics and environmental modifiable factors including smoking were also analyzed. Similar to previously published data, samples taken from smokers produced weaker signals compared to non-smokers (p<0.05). Although the number of non-smoking subjects was low, there was a clear decrease in cloning efficiency observed in keratinocyte cultures for these patients that requires further study. This study found that samples taken from smokers do not produce bystander signals, whereas samples taken from non-smokers can produce such signals following HDR brachytherapy. These findings highlight the importance of studying the interactions of multiple stressors including environmental modifiers with radiation, since some factors such as smoking may elicit protection in tumor cells which could counteract the effectiveness of radiation therapy.