Interaction of hyperlipidemia and reactive oxygen species: Insights from the lipid-raft platform

Age at onset of type 1 diabetes between puberty and 30 years old is associated with increased diabetic nephropathy risk

Diabetic nephropathy is a critical complication of patients with type 1 diabetes, while epidemiological studies were scarce among Asian countries. We conducted a cross-sectional study to identify factors associated with diabetic nephropathy by questionnaires, using student's t-test, chi-square test, and multivariable logistic regression. Among 898 participants, 16.7% had diabetic nephropathy. Compared with non-diabetic nephropathy patients, the patients with diabetic nephropathy had significantly higher percentage with onset age of type 1 diabetes between puberty and under 30 years old (female ≥ 12 or male ≥ 13 years old to 29 years old), longer diabetes duration, having family history of diabetes and diabetic nephropathy, accompanied with hypertension, hyperlipidemia, or coronary artery disease (CAD). Compared with patients with onset age before puberty, the odds of diabetic nephropathy occurrence increased to 1.61 times in patients with onset age between puberty and under 30 years old (p = 0.012) after adjusting diabetes duration. Age of diabetes onset between puberty and under 30 years old, diabetes duration, HbA1c, hospital admission within 3 years, diabetic retinopathy, hypertension, systolic blood pressure (SBP), triglyceride levels, and use of angiotensin converting enzyme inhibitor (ACEI) and/or angiotensin receptor blockers (ARB) were independent factors associated with diabetic nephropathy Screening for proteinuria is important in daily clinical practice and should be part of diabetes self-management education for patients with type 1 diabetes.

The long-term benefits of early intensive therapy in chronic diseases-the legacy effect

The 'legacy effect' refers to the long-term benefits of intensive therapy that are observed long after the end of clinical trials and trial interventions in chronic diseases such as diabetes, hyperlipidaemia and hypertension. It emphasizes the importance of intensive treatment to prevent long-term complications and mortality. In chronic kidney disease (CKD), the legacy effect is evident in various studies. Long-term nephroprotection in diabetes is well documented in major studies in the early stages of diabetes, such as Diabetes Control and Complications Trial-Epidemiology of Diabetes Interventions and Complications (DCCT-EDIC), UK Prospective Diabetes Study (UKPDS) and Intensified Multifactorial Intervention in Patients with Type 2 Diabetes and Microalbuminuria (STENO-2). These studies highlight the importance of intensive glycaemic control in reducing microvascular complications, including nephropathy, in patients with recently diagnosed type 1 and type 2 diabetes. However, the legacy effect is less evident in patients with long-term, established diabetes. In chronic glomerulonephritis, studies on immunoglobulin A nephropathy showed that early immunosuppressive treatment could have long-term beneficial effects on kidney function in children and adults with CKD. The Frequent Hemodialysis (FH) and the EXerCise Introduction To Enhance Performance in Dialysis (EXCITE) trials indicated that frequent haemodialysis and a personalized walking exercise program could improve clinical outcomes and reduce the long-term risk of death and hospitalization. The legacy effect concept underscores the importance of intensive intervention in chronic diseases, including CKD. This concept has significant implications for public health and warrants in-depth basic and clinical research to be better understood and exploited in clinical practice. However, its limitations should be considered when interpreting long-term observational data collected after a clinical trial. Appropriate study designs are necessary to investigate an unbiased legacy effect.

Coating with tripolyphosphate-crosslinked chitosan as a novel approach for enhanced stability of emulsomes following oral administration: Rutin as a model drug with improved anti-hyperlipidemic effect in rats

The aim of the current study is to preserve the emulsomal vesicles against the harsh condition of gastrointestinal tract (GIT), after oral administration, employing tripolyphosphate (TPP)-crosslinked chitosan as a protective coating layer. Rutin was used as a model drug with evaluation of anti-hyperlipidemic activity in rats. The rutin loaded unmodified emulsomes were prepared using tripalmitin and soybean phosphatidylcholine (SPC), by thin film method. Drug loading for the prepared formulations ranged between 6.80 and 15.50 %. The selected formulation (RT-Emuls-6) comprised tripalmitin and SPC, molar ratio 1:1, and exhibited particle size (PS) and zeta potential (ZP) of 150.40 nm and -35.35 mV, respectively. RT-Emuls-6 was then modified by coating with either solely chitosan (RT-Emuls-6-Ch) or TPP-crosslinked chitosan (RT-Emuls-6-Ch-TPP-1). The latter exhibited PS and ZP values of 269.60 nm and 37.17 mV, respectively. Transmission electron microscopy of RT-Emuls-6-Ch-TPP-1 showed a dense pale greyish layer of a coating layer of chitosan crosslinked with TPP surrounding SPC bilayers. Fourier transform infrared spectroscopy analysis along with X-ray powder diffraction confirmed cross-linking between chitosan and TPP. Stability study in the simulated GIT fluids revealed that the order of rutin retained percentage was RT-Emuls-6-Ch-TPP-1 > RT-Emuls-6-Ch > RT-Emuls-6 (80.02, 50.66 and 44.41 %, respectively for simulated gastric fluid and 63.50, 55.66 and 24.00 %, respectively for simulated intestinal fluid, after 2 h incubation). Anti-hyperlipidemic activity of rutin loaded emulsomes was evaluated, after oral administration, in a high fat diet-induced hyperlipidemia in rats. The order of activity was as follows: RT-Emuls-6-Ch-TPP-1 > RT-Emuls-6-Ch > RT-Emuls-6 > free rutin. These findings revealed the potential of TPP-crosslinked chitosan as a protective coating layer for enhancing the stability of emulsomes against the harsh condition of GIT. RT-Emuls-6-Ch-TPP-1 had a potent anti-hyperlipidemic activity via regulation of lipids, oxidative stress, irisin and uncoupling protein 1.

Loquat fruit peel extract regulates lipid metabolism and liver oxidative stress in mice: In vivo and in silico approaches

ETHNOPHARMACOLOGICAL RELEVANCE

In Moroccan traditional medicine, fresh or dried loquat (Eriobotrya japonica (Thunb.) Lindl.) fruit peels infused in water and taken for 45 days are used as natural remedies against hypercholesterolemia, hyperglycemia and cardiovascular diseases. This is the first experimental study approving the folk medicinal use of loquat fruit peels originated from eastern Morocco.

AIM OF THE STUDY

The study aims to investigate the effect of loquat fruit peel extract on lipid metabolism and liver oxidative status in mice as well as to predict the possible mechanisms.

MATERIALS AND METHODS

The study was carried out using high fat/fructose diet-induced hyperlipidemic mice model treated with the loquat peel extract for 45 days at two doses (100 and 200 mg/kg/day) in comparison to fenofibrate drug. The plasma, tissue, fecal and biliary lipids and blood glucose were analyzed using enzymatic methods. The liver oxidative status was evaluated and the polyphenol profiling was conducted using the HPLC-DAD method. Possible mechanisms involved in the observed pharmacological effects were predicted by in silico method.

RESULTS

The extract at a dose of 200 mg/kg possessed higher effect than at 100 mg/kg. It significantly reduced plasma total cholesterol (TC), triglycerides (TG), LDL-cholesterol, atherogenic index, LDL-C/HDL-C ratio and plasma glucose (-36%, -45%, -45%, -82%, -87%, 58%, respectively), while the HDL-cholesterol was increased (+172%). Moreover, the extract reduced TC and TG in the liver and adipose tissue by increasing their excretion in bile and fecal matter. It prevented the liver oxidative stress and decreased body weight and organ relative mass. The extract appears to be nontoxic (LD₅₀ > 5000 mg/kg) and contains five polyphenols including ferulic acid (32.74 ± 0.71 mg/g), caffeic acid (21.48 ± 0.32 mg/g), 5-O-Caffeoylquinic acid (112.15 ± 1.86 mg/g), chlorogenic acid (42.05 ± 0.92 mg/g) and quercetin (32.69 ± 0.68 mg/g). These phenolics and/or their circulating metabolites presented differential interaction capacities with the potential enzymes and transcription factors implicated in lipid homeostasis such as HMG-CoA reductase, lipoprotein lipase, fatty acid synthase, Cyp7a1, ABCG, PPARs, RXR, FXR and RAR.

CONCLUSION

Our findings justify the traditional use of loquat fruit peels and suggest that their aqueous extract could be used as substrate to produce phytotherapeutic drugs or dietary supplements to prevent hyperlipidemia, hyperglycemia and related cardiovascular diseases.

Oxidative Stress and MicroRNAs in Endothelial Cells under Metabolic Disorders

Reactive oxygen species (ROS) are radical oxygen intermediates that serve as important second messengers in signal transduction. However, when the accumulation of these molecules exceeds the buffering capacity of antioxidant enzymes, oxidative stress and endothelial cell (EC) dysfunction occur. EC dysfunction shifts the vascular system into a pro-coagulative, proinflammatory state, thereby increasing the risk of developing cardiovascular (CV) diseases and metabolic disorders. Studies have turned to the investigation of microRNA treatment for CV risk factors, as these post-transcription regulators are known to co-regulate ROS. In this review, we will discuss ROS pathways and generation, normal endothelial cell physiology and ROS-induced dysfunction, and the current knowledge of common metabolic disorders and their connection to oxidative stress. Therapeutic strategies based on microRNAs in response to oxidative stress and microRNA's regulatory roles in controlling ROS will also be explored. It is important to gain an in-depth comprehension of the mechanisms generating ROS and how manipulating these enzymatic byproducts can protect endothelial cell function from oxidative stress and prevent the development of vascular disorders.

Serum NOX1 and Raftlin as new potential biomarkers of Major Depressive Disorder: A study in treatment-naive first episode patients

INTRODUCTION

Biological factors are known to be important in understanding the pathogenesis of Major Depressive Disorder (MDD). Oxidative stress and neuroinflammation pathways are likely to play a critical role here.

METHODS

We undertook a study to investigate two novel biomarkers - serum NADPH oxidase 1 (NOX1) and Raftlin levels - in treatment-naive, smoking-free first episode patients with MDD compared to healthy controls (HCs) matched for age, sex and body mass index.

RESULTS

We found increased NOX1 and Raftlin levels in MDD patients compared to HCs. Both parameters showed very good diagnostic performance in the MDD group. In addition, we found a significant positive correlation between depression severity (HAMD) scores and both biomarker levels in the patient group.

CONCLUSION

To the best of our knowledge, this is the first human study to evaluate serum NOX1 and Raftlin levels in depression. NOX1, an important source of reactive oxygen species (ROS), and Raftlin, which may play a role in the inflammatory process, represent novel potential biomarkers of MDD. These findings support the implication of oxidative stress and inflammatory processes in patients with MDD, and indicate that the deteriorated ROS-antioxidant balance can be regulated via NOX1 in patients with depression.

Sex-Specific Variations in Vitamin D and Vitamin D Binding Protein (Vdbp) and Flipped Pattern of their Association in Preeclamptic Women with Dyslipidemia

BACKGROUND

Women with preeclampsia frequently have disorders of calcium metabolism during their pregnancies, including hypocalciuria and low vitamin D levels. The link between fetal sex and vitamin D and vitamin D binding protein levels in pregnancy and preeclampsia is not clear.

AIM

Present study was designed to explore sex-specific variations in vitamin D and vitamin D binding protein levels in maternal and umbilical cord blood samples for age and gestation matched 20 primigravida normotensive and 20 primigravida with preeclampsia with a singleton pregnancy.

METHODS

Routine investigations, vitamin D binding protein (VDBP), and serum vitamin D in both maternal serum and cord blood were measured in both groups. Association between maternal and cord blood vitamin D levels was highly positive in both cases and control with babies of either sex.

RESULTS

This association exhibited sexual dimorphism between cord blood vitamin D and vitamin D binding protein (VDBP) suggesting that the occurrence of pregnancy complications differs according to fetal sex with a higher cardiovascular and metabolic load for the mother in the presence of a male fetus.

CONCLUSION

Vitamin D binding protein (VDBP) measurement along with vitamin D level should be advised in clinical practice for early detection and screening.

Age-related hearing loss was accelerated by apoptosis of spiral ganglion and stria vascularis cells in ApoE KO mice with hyperglycemia and hyperlipidemia

Age-related hearing loss (ARHL) is associated with diabetes and/or dyslipidemia in humans. However, the detailed mechanism for the development of ARHL by diabetes and/or dyslipidemia has not been elucidated. In this study, we investigated the etiology of ARHL in apolipoprotein E (ApoE)-deficient mice with diabetes and dyslipidemia. The atherosclerotic CD-STZ (mice fed with a control diet and received an STZ injection), WD-con (mice fed with a western diet), and WD-STZ (mice fed with a western diet and received an STZ injection) mice showed a 2.4-, 4.9-, and 6.8-fold larger area, respectively, occupied by lesions throughout the aorta compared with the CD-con mice. A significantly larger area under the curve (AUC) was observed in the STZ-treated groups than in the non-treated groups based on the oral glucose tolerance test (OGTT). At 20 weeks of age, HbA_1c levels were significantly higher in the CD-STZ and WD-STZ mice than in the CD-con and WD-con mice. In all the groups, the auditory brainstem response (ABR) thresholds of the 16-week-old mice were significantly higher compared with those of the 8-week-old mice. In particular, in the WD-STZ mice, the ABR thresholds of the left and right ears reached the maximum decibel peak equivalent sound pressure levels (130 dBpeSPL), which is a sign of deafness. The apoptotic spiral ganglion neurons (SGNs) of the WD-STZ mice were significantly increased compared with those of the other three groups, indicating that SGN apoptosis resulted in hearing loss in STZ-induced diabetic ApoE KO mice fed with a WD. A significant loss of the stria vascularis cells was observed in the WD-STZ group compared with the CD-con mice. In the organ of Corti, few apoptotic hair cells were found in all the groups; however, no significant difference was observed. Therefore, we consider that the reduced hearing ability in the STZ-treated and WD-fed groups was attributed to the damage to the SGN and stria vascularis in the cochlea. Thus, our results indicated that ototoxicity by diabetes and/or dyslipidemia accelerated ARHL in ApoE KO mice, thereby suggesting the importance of appropriate treatment of patients with diabetes and/or dyslipidemia to prevent ARHL.

Lingering Dynamics of Type 2 Diabetes Mellitus Red Blood Cells in Retinal Arteriolar Bifurcations

It has been proven that the deformability of red blood cells (RBC) is reduced owing to changes in mechanical properties, such as diabetes mellitus and hypertension. To probe the effects of RBC morphological and physical parameters on the flow field in bifurcated arterioles, three types of RBC models with various degrees of biconcave shapes were built based on the in vitro experimental data. The dynamic behaviors of the RBCs in shear flow were simulated to validate the feasibility of the finite element-Arbitrary Lagrangian-Eulerian method with a moving mesh. The influences of the shear rate and viscosity ratios on RBC motions were investigated. The motion of RBCs in arteriolar bifurcations was further simulated. Abnormal variations in the morphological and physical parameters of RBCs may lead to diminished tank-tread motion and enhanced tumbling motion in shear flow. Moreover, abnormal RBC variations can result in slower RBC motion at the bifurcation with a longer transmit time and greater flow resistance, which may further cause inadequate local oxygen supply. These findings would provide useful insights into the microvascular complications in diabetes mellitus.

Reactive Oxygen Species Scavenging Nanomedicine for the Treatment of Ischemic Heart Disease

Ischemic heart disease (IHD) is the leading cause of disability and mortality worldwide. Reactive oxygen species (ROS) have been shown to play key roles in the progression of diabetes, hypertension, and hypercholesterolemia, which are independent risk factors that lead to atherosclerosis and the development of IHD. Engineered biomaterial-based nanomedicines are under extensive investigation and exploration, serving as smart and multifunctional nanocarriers for synergistic therapeutic effect. Capitalizing on cell/molecule-targeting drug delivery, nanomedicines present enhanced specificity and safety with favorable pharmacokinetics and pharmacodynamics. Herein, the roles of ROS in both IHD and its risk factors are discussed, highlighting cardiovascular medications that have antioxidant properties, and summarizing the advantages, properties, and recent achievements of nanomedicines that have ROS scavenging capacity for the treatment of diabetes, hypertension, hypercholesterolemia, atherosclerosis, ischemia/reperfusion, and myocardial infarction. Finally, the current challenges of nanomedicines for ROS-scavenging treatment of IHD and possible future directions are discussed from a clinical perspective.

Dietary Supplementation with Sea Buckthorn Berry Puree Alters Plasma Metabolomic Profile and Gut Microbiota Composition in Hypercholesterolemia Population

Sea buckthorn berries have been reported to have beneficial effects on plasma lipid profile and cardiovascular health. This study aimed to investigate the impact of intervention with sea buckthorn berry puree on plasma metabolomics profile and gut microbiota in hypercholesterolemic subjects. A total of 56 subjects with hypercholesterolemia consumed 90 g of sea buckthorn berry puree daily for 90 days, and plasma metabolomic profile was studied at 0 (baseline), 45, and 90 days of intervention by using proton nuclear magnetic resonance spectroscopy (¹H NMR). Gut microbiota composition was analyzed at the baseline and after 90 days of supplementation by using high-throughput sequencing. The plasma metabolic profile was significantly altered after 45 days of intervention as compared to the baseline (day 0). A clear trend of returning to the baseline metabolomic profile was observed in plasma when the intervention extended from 45 days to 90 days. Despite this, the levels of several key plasma metabolites such as glucose, lactate, and creatine were lowered at day 90 compared to the baseline levels, suggesting an improved energy metabolism in those patients. In addition, intervention with sea buckthorn puree enriched butyrate-producing bacteria and other gut microbes linked to lipid metabolisms such as Prevotella and Faecalibacterium while depleting Parasutterella associated with increased risks of cardiovascular disease. These findings indicate that sea buckthorn berries have potential in modulating energy metabolism and the gut microbiota composition in hypercholesterolemic patients.

Cytotoxic Effects of the Schweinfurthin Analog 5′-Methylschweinfurthin G in Malignant Plasma Cells

<b><i>Introduction:</i></b> Multiple myeloma (MM) is a B plasma cell malignancy currently incurable, and novel therapeutics are needed. Evidences regarding the effect of natural compound schweinfurthins suggest that hematological cancers showed growth inhibitory effects to this family of compounds at single nanomolar concentrations. In this study, we evaluated the cytotoxicity of the schweinfurthin synthetic analog 5′-methylschweinfurthin G (MeSG) in MM cell lines, to better understand the validity of this compound as a therapeutic candidate for further studies in MM. <b><i>Methods:</i></b> MeSG toxicity against MM cell lines RPMI-8226, MM.1S, and H-929 was evaluated. Trypan blue exclusion and MTT assays measured cell viability and mitochondrial activity, respectively. Flow cytometry was performed to detect apoptotic mitochondria. Flow cytometry and Western blotting techniques were used to investigate apoptosis and to examine the cell cycle. Western blotting was used to determine AKT activation upon MeSG treatment. <b><i>Results:</i></b> We provide evidence that in all MM cells analyzed, MeSG exerts diverse cytotoxic effects. MeSG treatment of MM.1S and H-929, but not in RPMI-8226, causes a loss of mitochondria membrane potential. MeSG causes an arrest in G₂/M, especially in RPMI-8226, supported by decreased levels of cyclin-B1 and early increased levels of p21. Finally, there is a diverse response to the MeSG treatment for AKT phosphorylation. MM.1S and H-929 showed a marked decrease in AKT phosphorylation at earlier time points compared to the RPMI-8226 line. <b><i>Conclusions:</i></b> MeSG cytotoxicity has been confirmed in all of 3 cell lines studied. Results suggest an early event of increased reactive oxygen species, and/or involvement of cholesterol homeostasis via decreased AKT activation, both of which are currently under investigation.

Age-Related Hearing Loss: The Link between Inflammaging, Immunosenescence, and Gut Dysbiosis

This article provides a theoretical overview of the association between age-related hearing loss (ARHL), immune system ageing (immunosenescence), and chronic inflammation. ARHL, or presbyacusis, is the most common sensory disability that significantly reduces the quality of life and has a high economic impact. This disorder is linked to genetic risk factors but is also influenced by a lifelong cumulative effect of environmental stressors, such as noise, otological diseases, or ototoxic drugs. Age-related hearing loss and other age-related disorders share common mechanisms which often converge on low-grade chronic inflammation known as “inflammaging”. Various stimuli can sustain inflammaging, including pathogens, cell debris, nutrients, and gut microbiota. As a result of ageing, the immune system can become defective, leading to the accumulation of unresolved inflammatory processes in the body. Gut microbiota plays a central role in inflammaging because it can release inflammatory mediators and crosstalk with other organ systems. A proinflammatory gut environment associated with ageing could result in a leaky gut and the translocation of bacterial metabolites and inflammatory mediators to distant organs via the systemic circulation. Here, we postulate that inflammaging, as a result of immunosenescence and gut dysbiosis, accelerates age-related cochlear degeneration, contributing to the development of ARHL. Age-dependent gut dysbiosis was included as a hypothetical link that should receive more attention in future studies.

Phytochemical Contents and Pharmacological Potential of Parkia speciosa Hassk. for Diabetic Vasculopathy: A Review

Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia and is considered a major health problem in the world. It is associated with endothelial dysfunction which causes progressive vascular damage. DM is a known risk factor for atherosclerosis and cardiovascular complications such as peripheral artery disease, coronary artery disease, and stroke. Medicinal plants may act as an alternative resource or adjunctive treatment option in the treatment of diabetes and its cardiovascular complications. Parkia speciosa (Fabaceae) is a plant found abundantly in the Southeast Asian region. Its seeds, with or without pods, and roots have long been used as a traditional medicine in this region to treat hypertension and diabetes. Studies have shown its numerous beneficial pharmacological properties. Extracts of P. speciosa, particularly from its seeds and empty pods, show the presence of polyphenols. They also exhibit potent antioxidant, hypoglycemic, anti-inflammatory, and antihypertensive properties. Its hypoglycemic properties are reported to be associated with the presence of β-sitosterol, stigmasterol, and stigmat-4-en-3-one. The current review aimed to provide an overview of the current status of P. speciosa, its pharmacological potential, and its phytochemical content in attenuating diabetic vasculopathy. Glycemic status, oxidative stress, inflammation, and hyperlipidemia are known to play pivotal roles in the initiation and severity of diabetic cardiovascular diseases; thus, targeting these factors might be beneficial for preventing and/or treating diabetic vasculopathy.

The Link between Gut Dysbiosis Caused by a High-Fat Diet and Hearing Loss

This review aims to provide a conceptual and theoretical overview of the association between gut dysbiosis and hearing loss. Hearing loss is a global health issue; the World Health Organisation (WHO) estimates that 2.5 billion people will be living with some degree of hearing loss by 2050. The aetiology of sensorineural hearing loss (SNHL) is complex and multifactorial, arising from congenital and acquired causes. Recent evidence suggests that impaired gut health may also be a risk factor for SNHL. Inflammatory bowel disease (IBD), type 2 diabetes, diet-induced obesity (DIO), and high-fat diet (HFD) all show links to hearing loss. Previous studies have shown that a HFD can result in microangiopathy, impaired insulin signalling, and oxidative stress in the inner ear. A HFD can also induce pathological shifts in gut microbiota and affect intestinal barrier (IB) integrity, leading to a leaky gut. A leaky gut can result in chronic systemic inflammation, which may affect extraintestinal organs. Here, we postulate that changes in gut microbiota resulting from a chronic HFD and DIO may cause a systemic inflammatory response that can compromise the permeability of the blood-labyrinth barrier (BLB) in the inner ear, thus inducing cochlear inflammation and hearing deficits.

Increased Fetal Cardiovascular Disease Risk: Potential Synergy Between Gestational Diabetes Mellitus and Maternal Hypercholesterolemia

Cardiovascular diseases (CVD) remain a major cause of death worldwide. Evidence suggests that the risk for CVD can increase at the fetal stages due to maternal metabolic diseases, such as gestational diabetes mellitus (GDM) and maternal supraphysiological hypercholesterolemia (MSPH). GDM is a hyperglycemic, inflammatory, and insulin-resistant state that increases plasma levels of free fatty acids and triglycerides, impairs endothelial vascular tone regulation, and due to the increased nutrient transport, exposes the fetus to the altered metabolic conditions of the mother. MSPH involves increased levels of cholesterol (mainly as low-density lipoprotein cholesterol) which also causes endothelial dysfunction and alters nutrient transport to the fetus. Despite that an association has already been established between MSPH and increased CVD risk, however, little is known about the cellular processes underlying this relationship. Our knowledge is further obscured when the simultaneous presentation of MSPH and GDM takes place. In this context, GDM and MSPH may substantially increase fetal CVD risk due to synergistic impairment of placental nutrient transport and endothelial dysfunction. More studies on the separate and/or cumulative role of both processes are warranted to suggest specific treatment options.

Increased plasma disequilibrium between pro- and anti-oxidants during the early phase resuscitation after cardiac arrest is associated with increased levels of oxidative stress end-products

BACKGROUND

Cardiac arrest (CA) results in loss of blood circulation to all tissues leading to oxygen and metabolite dysfunction. Return of blood flow and oxygen during resuscitative efforts is the beginning of reperfusion injury and is marked by the generation of reactive oxygen species (ROS) that can directly damage tissues. The plasma serves as a reservoir and transportation medium for oxygen and metabolites critical for survival as well as ROS that are generated. However, the complicated interplay among various ROS species and antioxidant counterparts, particularly after CA, in the plasma have not been evaluated. In this study, we assessed the equilibrium between pro- and anti-oxidants within the plasma to assess the oxidative status of plasma post-CA.

METHODS

In male Sprague-Dawley rats, 10 min asphyxial-CA was induced followed by cardiopulmonary resuscitation (CPR). Plasma was drawn immediately after achieving return of spontaneous circulation (ROSC) and after 2 h post-ROSC. Plasma was isolated and analyzed for prooxidant capacity (Amplex Red and dihydroethidium oxidation, total nitrate and nitrite concentration, xanthine oxidase activity, and iron concentration) and antioxidant capacity (catalase and superoxide dismutase activities, Total Antioxidant Capacity, and Iron Reducing Antioxidant Power Assay). The consequent oxidative products, such as 4-Hydroxyl-2-noneal, malondialdehyde, protein carbonyl, and nitrotyrosine were evaluated to determine the degree of oxidative damage.

RESULTS

After CA and resuscitation, two trends were observed: (1) plasma prooxidant capacity was lower during ischemia, but rapidly increased post-ROSC as compared to control, and (2) plasma antioxidant capacity was increased during ischemia, but either decreased or did not increase substantially post-ROSC as compared to control. Consequently, oxidation products were increased post-ROSC.

CONCLUSION

Our study evaluated the disbalance of pro- and anti-oxidants after CA in the plasma during the early phase after resuscitation. This disequilibrium favors the prooxidants and is associated with increased levels of downstream oxidative stress-induced end-products, which the body's antioxidant capacity is unable to directly mitigate. Here, we suggest that circulating plasma is a major contributor to oxidative stress post-CA and its management requires substantial early intervention for favorable outcomes.

Cardioprotective effects of Fenugreek (Trigonella foenum-graceum) seed extract in streptozotocin induced diabetic rats

Introduction: Inadequate control of diabetes mellitus (DM) leads to considerable cardiovascular implications like diabetic cardiomyopathy (DCM). Cardiomyocyte apoptosis is one of the main mechanisms of DCM pathogenesis associated with hyperglycemia, oxidative stress, inflammation, hyperlipidemia and several other factors. Trigonella foenum-graecum (Fenugreek) has been long used as a traditional medicine and has many therapeutic effects, including anti-diabetic, anti-hyperlipidemia, anti-inflammatory and anti-oxidant properties. The current study aimed to investigate cardioprotective effects of fenugreek seed on diabetic rats. Methods: Diabetes was induced in forty-two male rats by injection of streptozotocin (STZ) (60 mg/ kg). Diabetic animals were treated with three different doses of fenugreek seed extract (50, 100 and 200 mg/kg) or metformin (300 mg/kg) for six weeks by gavage. Nondiabetic rats served as controls. Glucose, cholesterol, and triglycerides levels were measured in the blood samples, and oxidative stress markers as well as gene expression of ICAM1 , Bax and Bcl2 were assessed in the cardiac tissues of the experimental groups. Results: Diabetic rats exhibited increased serum glucose, cholesterol and triglycerides levels, elevated markers of oxidative stress thiobarbituric acid-reacting substances (TBARS) levels , total thiol groups (SH), catalase (CAT) and superoxide dismutase (SOD) activity, and enhanced apoptosis cell death (ratio of Bax/Bcl2). Fenugreek seed extract considerably improved metabolism abnormalities, attenuated oxidative stress and diminished apoptosis index. Conclusion: Our study suggests that fenugreek seed may protect the cardiac structure in STZ-induced diabetic rats by attenuating oxidative stress and apoptosis.

The Crucial Role of Xanthine Oxidase in CKD Progression Associated with Hypercholesterolemia

In the present study, we investigated the effects of xanthine oxidase (XO) inhibition on cholesterol-induced renal dysfunction in chronic kidney disease (CKD) mice, and in low-density lipoprotein (LDL)-treated human kidney proximal tubule epithelial (HK-2) cells. ApoE knockout (KO) mice underwent uninephrectomy to induce CKD, and were fed a normal diet or high-cholesterol (HC) diet along with the XO inhibitor topiroxostat (1 mg/kg/day). HK-2 cells were treated with LDL (200 µg/mL) and topiroxostat (5 µM) or small interfering RNA against xanthine dehydrogenase (siXDH; 20 nM). In uninephrectomized ApoE KO mice, the HC diet increased cholesterol accumulation, oxidative stress, XO activity, and kidney damage, while topiroxostat attenuated the hypercholesterolemia-associated renal dysfunction. The HC diet induced cholesterol accumulation by regulating the expressions of genes involved in cholesterol efflux (Nr1h3 and Abca1) and synthesis (Srebf2 and Hmgcr), which was reversed by topiroxostat. Topiroxostat suppressed the expressions of genes related to hypercholesterolemia-associated inflammation and fibrosis in the unilateral kidney. LDL stimulation evoked changes in the cholesterol metabolism, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and NF-κB pathways in HK-2 cells, which were mitigated by XO inhibition with topiroxostat or siXDH. These findings suggest that XO inhibition exerts renoprotective effects against hypercholesterolemia-associated kidney injury. XO could be a novel therapeutic target for hypercholesterolemia-associated kidney injury in uninephrectomized patients.

Red blood cell dysfunction: a new player in cardiovascular disease

The primary role of red blood cells (RBCs) is to transport oxygen to the tissues and carbon dioxide to the lungs. However, emerging evidence suggests an important role of the RBC beyond being just a passive carrier of the respiratory gases. The RBCs are of importance for redox balance and are actively involved in the regulation of vascular tone, especially during hypoxic and ischaemic conditions by the release of nitric oxide (NO) bioactivity and adenosine triphosphate. The role of the RBC has gained further interest after recent discoveries demonstrating a markedly altered function of the cell in several pathological conditions. Such alterations include increased adhesion capability, increased formation of reactive oxygen species as well as altered protein content and enzymatic activities. Beyond signalling increased oxidative stress, the altered function of RBCs is characterized by reduced export of NO bioactivity regulated by increased arginase activity. Of further importance, the altered function of RBCs has important implications for several cardiovascular disease conditions. RBCs have been shown to induce endothelial dysfunction and to increase cardiac injury during ischaemia-reperfusion in diabetes mellitus. Finally, this new knowledge has led to novel therapeutic possibilities to intervene against cardiovascular disease by targeting signalling in the RBC. These novel data open up an entirely new view on the underlying pathophysiological mechanisms behind the cardiovascular disease processes in diabetes mellitus mediated by the RBC. This review highlights the current knowledge regarding the role of RBCs in cardiovascular regulation with focus on their importance for cardiovascular dysfunction in pathological conditions and therapeutic possibilities for targeting RBCs in cardiovascular disease.

Engineering blood outgrowth endothelial cells to optimize endothelial nitric oxide synthase and extracellular matrix production for coating of blood contacting surfaces

Coverage of blood contacting surfaces by a functional endothelial layer is likely required to induce and maintain homeostasis. Blood outgrowth endothelial cells (BOECs), cultured from human peripheral blood monocytes, are readily available and functional autologous endothelial source that may represent a reasonable alternative to vascular derived cells. Endothelial nitric oxide synthase (eNOS) produces NO, an important factor that regulates homeostasis at the blood-contacting surface. We found that BOECs express markedly lower levels of eNOS protein (34% ± 13%, Western blot) and mRNA (29% ± 17%, qRT-PCR), as well as exhibiting reduced activity (49% ± 18%, Nitrite analysis) when compared to human umbilical vein endothelial cells (HUVECs) and human aortic endothelial cells. HUVECs grown on fibronectin, type I collagen, or laminin -coated surfaces exhibited significant reduction of eNOS mRNA and protein expression. However, no decrease in eNOS levels was observed in BOECs. Interestingly BOECs expressed significantly higher Collagen (Col) I compared to HUVECs, and blocking Col I synthesis significantly enhanced eNOS expression in BOECs. Inhibition of β1 integrin, focal adhesion kinase (FAK), or actin polymerization increased eNOS in both BOECs and HUVECs suggesting involvement of a signaling pathway culminating in stabilization of the cytoskeleton. Finally, we demonstrated that a Rho-associated protein kinases (ROCK) inhibitor, as a disruptor of actin stabilization, enhanced both eNOS expression and bioactivity. Taken together, our findings demonstrate that cell-ECM interactions are fundamental to the regulation of eNOS in BOECs and suggest that disruption of key intracellular pathways (such as ROCK) may be necessary to enhance functional activity of an endothelialized surface. STATEMENT OF SIGNIFICANCE: Development of biocompatible blood-contacting biomaterial surfaces has not been possible to date, leading many investigators to believe that a complete autologous endothelial layer will be necessary. Blood outgrowth endothelial cells (BOECs), cultured from human peripheral blood monocytes, are readily available and functional autologous endothelial source. Endothelial nitric oxide synthase (eNOS) produces NO, an important factor that regulates homeostasis at the blood-contacting surface. In this study, we show that eNOS displays limited expression in cultured BOECs. We further demonstrate that a strong negative regulation of eNOS is mediated by collagen substrates and that treatment with ROCK inhibitor could enhance both eNOS expression and activity in BOECs and help to rapidly establish a functional autologous endothelial layer on cardiovascular biomaterials.

Perindopril ameliorates experimental Alzheimer's disease progression: role of amyloid β degradation, central estrogen receptor and hyperlipidemic-lipid raft signaling

Accumulating evidence indicates that over-stimulation of angiotensin-converting enzyme 1 (ACE1) activity is associated with β-amyloid (Aβ) and phosphorylated tau (p-tau)-induced apoptosis, oxido-nitrosative neuroinflammatory stress and neurodegeneration in Alzheimer's disease (AD). Alternatively, activation of the ACE2, the metalloprotease neprilysin (Neutral Endopeptidase; NEP) and the insulin-degrading enzyme (IDE) could oppose the effects of ACE1 activation. We aim to investigate the relationship between ACE1/ACE2/NEP/IDE and amyloidogenic/hyperlipidemic-lipid raft signaling in hyperlipidemic AD model. Induction of AD was performed in ovariectomized female rats with high-fat high fructose diet (HFFD) feeding after 4 weeks following D-galactose injection (150 mg/kg). The brain-penetrating ACE1 inhibitor perindopril (0.5 mg/kg/day, p.o.) was administered on a daily basis for 30 days. Perindopril significantly decreased hippocampal expression of ACE1 and increased expression of ACE2, NEP and IDE. Perindopril markedly decreased Aβ_1-42, improved lipid profile and ameliorated the lipid raft protein markers caveolin1 (CAV1) and flotillin 1 (FLOT1). This was accompanied by decreased expression of p-tau and enhancement of cholinergic neurotransmission, coupled with decreased oxido-nitrosative neuroinflammatory stress, enhancement of blood-brain barrier (BBB) functioning and lower expression of the apoptotic markers glial fibrillary acidic protein (GFAP), Bax and β-tubulin. In addition, perindopril ameliorated histopathological damage and improved learning, cognitive and recognition impairment as well as depressive behavior in Morris water maze, Y maze, novel object recognition and forced swimming tests, respectively. Conclusively, perindopril could improve cognitive defects in AD rats, at least through activation of ACE2/NEP/IDE and inhibition of ACE1 and subsequent modulation of amyloidogenic/hyperlipidemic-lipid raft signaling and oxido-nitrosative stress.

Short-term high-fat diet intake leads to exacerbation of concanavalin A-induced liver injury through the induction of procoagulation state

Obesity and high-fat diet (HFD) are known to cause proinflammatory and procoagulation states and suggested to become a risk of developing thromboembolic diseases. Non-alcoholic fatty liver disease (NAFLD) is usually associated with obesity and HFD, and a part of NAFLD is known to progress to nonalcoholic steatohepatitis (NASH), the pathogenesis of which has not been fully elucidated. In the current study, we examined the influence of short-term HFD on hepatic expression of the molecules related to inflammation, coagulation, metabolism, and cellular stresses from the perspective that HFD itself can be a risk for the development to NASH. In the analysis in short-term (4 days to 14 days) HFD-fed mice, we found out that HFD increased hepatic expression of IFN-γ, TNF-α, IL-10, monocyte chemotactic protein-1 (MCP-1), tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1) mRNAs, and fibrin/fibrinogen deposition in the liver tissues. And it was suggested that metabolic alterations and endoplasmic reticulum (ER) stresses induced by the HFD intake were associated with this proinflammatory and procoagulation states. When we administered concanavalin A (Con A) to these HFD-fed mice, the extent of liver injury was dramatically exacerbated in HFD-fed mice. Heparin treatment to Con A-administered, HFD-fed mice (for 4 days) profoundly ameliorated the extent of liver injury. These suggest that even short-term of HFD intake induces proinflammatory and procoagulation states in the liver and thereby increases the susceptibility of the liver to circulating inflammatory stimuli. We think that it may explain a part of NASH pathogenesis.

Can Nutritional Intervention for Obesity and Comorbidities Slow Down Age-Related Hearing Impairment?

BACKGROUND

Age-related hearing impairment (ARHI), the most common sensory deficit in the elderly, is associated with enormous social and public health burdens. Emerging evidence has suggested that obesity and comorbidities might increase the risk of ARHI. However, no reviews have been published that address the role of nutritional interventions for obesity and comorbidities in the prevention of ARHI.

METHODS

A PubMed database search was conducted to identify the relationship between obesity and ARHI. "Obesity", "metabolic syndrome", "adipose-derived hormone", "fatty acid", and "age-related hearing impairment" were included as keywords.

RESULTS

A total of 89 articles was analyzed with 39 articles of relevance to ARHI. A high-fat diet may induce oxidative stress, mitochondrial damage, and apoptosis in the inner ear. Statins have been shown to delay the progression of ARHI by improving the lipid profile, reducing oxidative stress, and inhibiting endothelial inflammation. Aldosterone could exert protective effects against ARHI by upregulating the Na-K-2Cl co-transporter 1 in the cochlea. Omega-3 polyunsaturated fatty acids could preserve the cochlear microcirculation by reducing dyslipidemia and inhibiting inflammation. Alpha-lipoic acid and lecithin might delay the progression of ARHI by protecting cochlear mitochondrial DNA from damage due to oxidative stress. Tea and ginseng might protect against ARHI through their anti-obesity and anti-diabetic effects.

CONCLUSIONS

Nutritional interventions for obesity and comorbidities, including a low-fat diet, supplementation with statins, aldosterone, omega-3 polyunsaturated fatty acids, alpha-lipoic acids, lecithin, tea, and ginseng, may protect against the development of ARHI.

Crosstalk between chitosan and cell signaling pathways

The field of tissue engineering (TE) experiences its most exciting time in the current decade. Recent progresses in TE have made it able to translate into clinical applications. To regenerate damaged tissues, TE uses biomaterial scaffolds to prepare a suitable backbone for tissue regeneration. It is well proven that the cell-biomaterial crosstalk impacts tremendously on cell biological activities such as differentiation, proliferation, migration, and others. Clarification of exact biological effects and mechanisms of a certain material on various cell types promises to have a profound impact on clinical applications of TE. Chitosan (CS) is one of the most commonly used biomaterials with many promising characteristics such as biocompatibility, antibacterial activity, biodegradability, and others. In this review, we discuss crosstalk between CS and various cell types to provide a roadmap for more effective applications of this polymer for future uses in tissue engineering and regenerative medicine.

Inhibition of LPS-stimulated ecto-adenosine deaminase attenuates endothelial cell activation

Vascular inflammation is an important factor in the pathophysiology of cardiovascular diseases, such as atherosclerosis. Changes in the extracellular nucleotide and in particular adenosine catabolism may alter a chronic inflammation and endothelial activation. This study aimed to evaluate the relation between vascular ecto-adenosine deaminase (eADA) activity and endothelial activation in humans and to analyze the effects of LPS-mediated inflammation on this activity as well as mechanisms of its increase. Moreover, we investigated a therapeutic potential of ADA inhibition by deoxycofromycin (dCF) for endothelial activation. We demonstrated a positive correlation of vascular eADA activity and ADA1 mRNA expression with endothelial activation parameters in humans with atherosclerosis. The activation of vascular eADA was also observed under LPS stimulation in vivo along with endothelial activation, an increase in markers of inflammation and alterations in the lipid profile of a rat model. Ex vivo and in vitro studies on human specimen demonstrated that at an early stage of vascular pathology, eADA activity originated from activated endothelial cells, while at later stages also from an inflammatory infiltrate. We proposed that LPS-stimulated increase in endothelial adenosine deaminase activity could be a result of IL-6/JAK/STAT pathway activation, since the lack of IL-6 in mice was associated with lower vascular and plasma eADA activities. Furthermore, the inhibitors of JAK/STAT pathway decreased LPS-stimulated adenosine deaminase activity in endothelial cells. We demonstrated that cell surface eADA activity could be additionally regulated by transcytosis pathways, as exocytosis inhibitors including lipid raft inhibitor, methyl-β-cyclodextrin decreased LPS-induced eADA activity. This suggests that cholesterol-dependent protein externalization mediated by lipid rafts could be an important factor in the eADA increase. Moreover, endocytosis inhibitors and exocytosis activators increased this activity on the cell surface. Furthermore, the inhibition of adenosine deaminase in endothelial cells in vitro attenuated LPS-mediated IL-6 release and soluble ICAM-1 and VCAM-1 concentration in the incubation medium through the restoration of the extracellular adenosine pool and adenosine receptor-dependent pathways. This study demonstrated that the vascular endothelial eADA activity remains under control of inflammatory mediators acting through JAK/STAT pathway that could be further modified by dyslipidemic-dependent exocytosis and transcytosis pathways. Inhibition of eADA blocked endothelial activation suggesting a crucial role of this enzyme in the control of vascular inflammation. This supports the concept of eADA targeted vascular protection therapy.

Dual antioxidant structures with potent anti-inflammatory, hypolipidemic and cytoprotective properties

Novel amide derivatives of trolox, 3,5-di-tert-butyl-4-hydroxybenzoic acid, (E)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylic acid and cinnamic acid with cysteamine and l-cysteine ethyl ester were synthesised. In four cases, the disulfide derivatives were also isolated and tested. All compounds were examined for antioxidant activity, expressed as their ability to inhibit lipid peroxidation and to scavenge free radicals. They were found to demonstrate up to 17-fold better activity than that of the parent antioxidant acids. They could reduce acute inflammation up to 87%. The most active antioxidant compounds were further tested for their in vivo hypolipidemic effect, which ranged from 47% to 73%, and for their ability to protect the liver against oxidative toxicity caused by high paracetamol dose. The disulfide derivatives of 3,5-di-tert-butyl-4-hydroxybenzoic acid and cinnamic acid had no antioxidant activity and presented equal or lower anti-inflammatory effect than their thiol analogues, indicating that their molecular characteristics may not permit biological barrier penetration.