Redox Homeostasis Alteration Is Restored through Melatonin Treatment in COVID-19 Patients: A Preliminary Study.

Type II pneumocytes are the target of the SARS-CoV-2 virus, which alters their redox homeostasis to increase reactive oxygen species (ROS). Melatonin (MT) has antioxidant proprieties and protects mitochondrial function. In this study, we evaluated whether treatment with MT compensated for the redox homeostasis alteration in serum from COVID-19 patients. We determined oxidative stress (OS) markers such as carbonyls, glutathione (GSH), total antioxidant capacity (TAC), thiols, nitrites (NO2-), lipid peroxidation (LPO), and thiol groups in serum. We also studied the enzymatic activities of glutathione peroxidase (GPx), glutathione-S-transferase (GST), reductase (GR), thioredoxin reductase (TrxR), extracellular superoxide dismutase (ecSOD) and peroxidases. There were significant increases in LPO and carbonyl quantities (p ≤ 0.03) and decreases in TAC and the quantities of NO2-, thiols, and GSH (p < 0.001) in COVID-19 patients. The activities of the antioxidant enzymes such as ecSOD, TrxR, GPx, GST, GR, and peroxidases were decreased (p ≤ 0.04) after the MT treatment. The treatment with MT favored the activity of the antioxidant enzymes that contributed to an increase in TAC and restored the lost redox homeostasis. MT also modulated glucose homeostasis, functioning as a glycolytic agent, and inhibited the Warburg effect. Thus, MT restores the redox homeostasis that is altered in COVID-19 patients and can be used as adjuvant therapy in SARS-CoV-2 infection.

The usefulness of the genetic panel in the classification and refinement of diagnostic accuracy of Mexican patients with Marfan syndrome and other connective tissue disorders.

Marfan syndrome (MFS) is a multisystem genetic disorder with over 3000 mutations described in the fibrillin 1 (FBN1) gene. Like MFS, other connective tissue disorders also require a deeper understanding of the phenotype-genotype relationship due to the complexity of the clinical presentation, where diagnostic criteria often overlap. Our objective was to identify mutations in patients with connective tissue disorders using a genetic multipanel and to analyze the genotype-phenotype associations in a cohort of Mexican patients. We recruited 136 patients with MFS and related syndromes from the National Institute of Cardiology. Mutations were identified using next-generation sequencing (NGS). To examine the correlation between mutation severity and severe cardiovascular conditions, we focused on patients who had undergone Bentall-de Bono surgery or aortic valve repair. The genetic data obtained allowed us to reclassify the initial clinical diagnosis across various types of connective tissue disorders. The transforming growth factor beta receptor 2 (TGFBR2) rs79375991 mutation was found in 10 out of 16 (63%) Loeys-Dietz patients. We observed a high prevalence (65%) of more severe mutations, such as frameshift indels and stop codons, among patients requiring invasive treatments like aortic valve-sparing surgery, Bentall and de Bono procedures, or aortic valve replacement due to severe cardiovascular injury. Although our study did not achieve precise phenotype-genotype correlations, it underscores the importance of a multigenetic panel evaluation. This could pave the way for a more comprehensive diagnostic approach and inform medical and surgical treatment decision-making.

Evaluation of the participation of ABCA1 transporter in epicardial and mediastinal adipose tissue from patients with coronary artery disease

ABSTRACT Objective: Recent studies have shown a relationship between adipose tissue and coronary artery disease (CAD). The ABCA1 transporter regulates cellular cholesterol content and reverses cholesterol transport. The aim of this study was to determine the relationship between single nucleotide polymorphisms (SNPs) R230C, C-17G, and C-69T and their expression in epicardial and mediastinal adipose tissue in Mexican patients with CAD. Subjects and methods: The study included 71 patients with CAD and a control group consisting of 64 patients who underwent heart valve replacement. SNPs were determined using TaqMan probes. mRNA was extracted using TriPure Isolation from epicardial and mediastinal adipose tissue. Quantification and expression analyses were done using RT-qPCR. Results: R230C showed a higher frequency of the GG genotype in the CAD group (70.4%) than the control group (57.8%) [OR 0.34, 95% CI (0.14-0.82) p = 0.014]. Similarly, C-17G (rs2740483) showed a statistically significant difference in the CC genotype in the CAD group (63.3%) in comparison to the controls (28.1%) [OR 4.42, 95% CI (2.13-9.16), p = 0.001]. mRNA expression in SNP R230C showed statistically significant overexpression in the AA genotype compared to the GG genotype in CAD patients [11.01 (4.31-15.24) vs. 3.86 (2.47-12.50), p = 0.015]. Conclusion: The results suggest that the GG genotype of R230C and CC genotype of C-17G are strongly associated with the development of CAD in Mexican patients. In addition, under-expression of mRNA in the GG genotype in R230C is associated with patients undergoing revascularization.

Impact of Treatment with Antioxidants as an Adjuvant to Standard Therapy in Patients with Septic Shock: Analysis of the Correlation between Cytokine Storm and Oxidative Stress and Therapeutic Effects.

Cellular homeostasis is lost or becomes dysfunctional during septic shock due to the activation of the inflammatory response and the deregulation of oxidative stress. Antioxidant therapy administered alongside standard treatment could restore this lost homeostasis. We included 131 patients with septic shock who were treated with standard treatment and vitamin C (Vit C), vitamin E (Vit E), N-acetylcysteine (NAC), or melatonin (MT), in a randomized trial. Organ damage quantified by Sequential Organ Failure Assessment (SOFA) score, and we determined levels of Interleukins (IL) IL1ß, Tumor necrosis factor alpha (TNFα), IL-6, monocyte chemoattractant protein-1 (MCP-1), Transforming growth factor B (TGFß), IL-4, IL-10, IL-12, and Interferon-γ (IFNγ). The SOFA score decreased in patients treated with Vit C, NAC, and MT. Patients treated with MT had statistically significantly reduced of IL-6, IL-8, MCP-1, and IL-10 levels. Lipid peroxidation, Nitrates and nitrites (NO3- and NO2-), glutathione reductase, and superoxide dismutase decreased after treatment with Vit C, Vit E, NAC, and MT. The levels of thiols recovered with the use of Vit E, and all patients treated with antioxidants maintained their selenium levels, in contrast with controls (p = 0.04). The findings regarding oxidative stress markers and cytokines after treatment with antioxidants allow us to consider to future the combined use of antioxidants in a randomized clinical trial with a larger sample to demonstrate the reproducibility of these beneficial effects.

N-Acetyl Cysteine Restores the Diminished Activity of the Antioxidant Enzymatic System Caused by SARS-CoV-2 Infection: Preliminary Findings.

SARS-CoV-2 infects type II pneumocytes and disrupts redox homeostasis by overproducing reactive oxygen species (ROS). N-acetyl cysteine (NAC) is a precursor of the synthesis of glutathione (GSH) and it restores the loss of redox homeostasis associated to viral infections. The aim of the study is to evaluate the effect of the treatment with NAC on the enzymatic antioxidant system in serum from patients infected by SARS-CoV-2. We evaluated the enzymatic activities of thioredoxin reductase (TrxR), glutathione peroxidase (GPx), -S-transferase (GST), and reductase (GR) by spectrophotometry and the concentrations of the glutathione (GSH), total antioxidant capacity (TAC), thiols, nitrites (NO2-), and lipid peroxidation (LPO) in serum. The activity of the extracellular super oxide dismutase (ecSOD) was determined by native polyacrylamide gels, and 3-nitrotyrosine (3-NT) was measured by ELISA. A decrease in the activities of the ecSOD, TrxR, GPx, GST GR, (p = 0 ≤ 0.1), and the GSH, TAC, thiols, and NO2- (p ≤ 0.001) concentrations and an increase in LPO and 3-NT (p = 0.001) concentrations were found in COVID-19 patients vs. healthy subjects. The treatment with NAC as an adjuvant therapy may contribute to a reduction in the OS associated to the infection by SARS-CoV-2 through the generation of GSH. GSH promotes the metabolic pathways that depend on it, thus contributing to an increase in TAC and to restore redox homeostasis.

Expressions of mRNA and encoded proteins of mitochondrial uncoupling protein genes (UCP1, UCP2, and UCP3) in epicardial and mediastinal adipose tissue and associations with coronary artery disease.

Objective: To evaluate the expression of UCP1, UCP2, and UCP3 mRNA and encoded proteins in epicardial and mediastinal adipose tissues in patients with coronary artery disease (CAD). Subjects and methods: We studied 60 patients with CAD and 106 patients undergoing valve replacement surgery (controls). Expression levels of UCP1, UCP2, and UCP3 mRNA and encoded proteins were measured by quantitative real-time PCR and Western blot analysis, respectively. Results: : We found increased UCP1, UCP2, and UCP3 mRNA levels in the epicardial adipose tissue in the CAD versus the control group, and higher UCP1 and UCP3 mRNA expression in the epicardial compared with the mediastinal tissue in the CAD group. There was also increased expression of UCP1 protein in the epicardial tissue and UCP2 protein in the mediastinum tissue in patients with CAD. Finally, UCP1 expression was associated with levels of fasting plasma glucose, and UCP3 expression was associated with levels of high-density lipoprotein cholesterol and low-density cholesterol in the epicardial tissue. Conclusion: Our study supports the hypothesis that higher mRNA expression by UCP genes in the epicardial adipose tissue could be a protective mechanism against the production of reactive oxygen species and may guard the myocardium against damage. Thus, UCP levels are essential to maintain the adaptive phase of cardiac injury in the presence of metabolic disorders.

Expressions of mRNA and encoded proteins of mitochondrial uncoupling protein genes (UCP1, UCP2, and UCP3) in epicardial and mediastinal adipose tissue and associations with coronary artery disease

ABSTRACT Objective: To evaluate the expression of UCP1, UCP2, and UCP3 mRNA and encoded proteins in epicardial and mediastinal adipose tissues in patients with coronary artery disease (CAD). Subjects and methods: We studied 60 patients with CAD and 106 patients undergoing valve replacement surgery (controls). Expression levels of UCP1, UCP2, and UCP3 mRNA and encoded proteins were measured by quantitative real-time PCR and Western blot analysis, respectively. Results: We found increased UCP1, UCP2, and UCP3 mRNA levels in the epicardial adipose tissue in the CAD versus the control group, and higher UCP1 and UCP3 mRNA expression in the epicardial compared with the mediastinal tissue in the CAD group. There was also increased expression of UCP1 protein in the epicardial tissue and UCP2 protein in the mediastinum tissue in patients with CAD. Finally, UCP1 expression was associated with levels of fasting plasma glucose, and UCP3 expression was associated with levels of high-density lipoprotein cholesterol and low-density cholesterol in the epicardial tissue. Conclusions: Our study supports the hypothesis that higher mRNA expression by UCP genes in the epicardial adipose tissue could be a protective mechanism against the production of reactive oxygen species and may guard the myocardium against damage. Thus, UCP levels are essential to maintain the adaptive phase of cardiac injury in the presence of metabolic disorders.

Deodorized Garlic Decreases Oxidative Stress Caused by Lipopolysaccharide in Rat Heart through Hydrogen Sulfide: Preliminary Findings.

Deodorized garlic (DG) may favor the activity of the antioxidant enzymes and promote the synthesis of hydrogen sulfide (H2S). The objective was to test if DG favors an increase in H2S and if it decreases the oxidative stress caused by lipopolysaccharide (LPS) in rat hearts. A total of 24 rats were divided into 4 groups: Group 1 control (C), Group 2 LPS, Group 3 DG, and Group 4 LPS plus DG. The cardiac mechanical performance (CMP), coronary vascular resistance (CVR), and oxidative stress markers, such as total antioxidant capacity (TAC), glutathione (GSH), selenium (Se), lipid peroxidation (LPO), thiols, hydrogen sulfide (H2S), and the activities and expressions of thioredoxin reductase (TrxR), glutathione peroxidase (GPx), and glutathione-S-transferase (GST), cystathionine synthetase (CBS), cystathionine γ-lyase (CTH), iNOS, and eNOS-p, were analyzed in the heart. Infarct zones in the cardiac tissue were present (p = 0.01). The CMP and CVR decreased and increased (p ≤ 0.05), TAC, GSH, H2S, NO, thiols, and GST activity (p ≤ 0.01) decreased, and LPO and iNOS increased (p ≤ 0.05). The activities and expressions of TrxR, GPx, eNOS-p, CTH, and CBS (p ≤ 0.05) decreased with the LPS treatment; however, DG normalized this effect. DG treatment decreases heart damage caused by LPS through the cross-talk between the H2S and NO systems.

Excessive Consumption Hibiscus sabdariffa L. Increases Inflammation and Blood Pressure in Male Wistar Rats via High Antioxidant Capacity: The Preliminary Findings.

Hibiscus sabdariffa L. (HSL) has high amounts of antioxidants and many beneficial effects in several pathologies. However, few studies describe the possible harmful effects of high concentrations of HSL. Here we evaluate the effect of excessive and chronic consumption of infusions with different percentages of HSL on some oxidative stress markers in serum, and the possible association with inflammation and increased systolic blood pressure (SBP), in healthy rats. A total of 32 male Wistar rats were used to form 4 groups with 8 animals each. Group 1 control (drinking tap water), group 2, 3 and 4, drinking water supplemented with 15, 30 and 60 g/L of HSL calyxes respectively. SBP was evaluated and determinations in serum of the NO3-/NO2- ratio, glutathione (GSH), total antioxidant capacity (TAC), selenium (Se), TNF-α, IL-1α/IL-1F1, IL-1ß, IL-10, extracellular superoxide dismutase (EcSOD), thioredoxin reductase (TrxR) and glutathione peroxidase (GPx) activities, were evaluated. The SBP (p = 0.01), GPx activity, GSH, TAC, Se, TNF-α and EcSOD activities (p ≤ 0.001) and IL-1α/IL-1F1, IL-1ß, TrxR and NO3-/NO2- (p ≤ 0.05), were increased but IL-10 (p < 0.001) was decreased in rats that consumed the 3 and 6% HSL infusions. The excessive and chronic consumption of HSL may increase the TAC that could lead to a proinflammatory state which is associated with hypertension.

Cardiac Magnetic Resonance in Rheumatology to Detect Cardiac Involvement Since Early and Pre-clinical Stages of the Autoimmune Diseases: A Narrative Review.

Autoimmune diseases (ADs) encompass multisystem disorders, and cardiovascular involvement is a well-known feature of autoimmune and inflammatory rheumatic conditions. Unfortunately, subclinical and early cardiovascular involvement remains clinically silent and often undetected, despite its well-documented impact on patient management and prognostication with an even more significant effect on severe and future MACE events as the disease progresses. Cardiac magnetic resonance imaging (MRI), today, commands a unique position of supremacy versus its competition in cardiac assessment and is the gold standard for the non-invasive evaluation of cardiac function, structure, morphology, tissue characterization, and flow with the capability of evaluating biventricular function; myocardium for edema, ischemia, fibrosis, infarction; valves for thickening, large masses; pericardial inflammation, pericardial effusions, and tamponade; cardiac cavities for thrombosis; conduction related abnormalities and features of microvascular and large vessel involvement. As precise and early detection of cardiovascular involvement plays a critical role in improving the outcome of rheumatic and autoimmune conditions, our review aims to highlight the evolving role of CMR in systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), rheumatoid arthritis (RA), systemic sclerosis (SSc), limited sclerosis (LSc), adult-onset Still's disease (AOSD), polymyositis (PM), dermatomyositis (DM), eosinophilic granulomatosis with polyangiitis (EGPA) (formerly Churg-Strauss syndrome), and DRESS syndrome (DS). It draws attention to the need for concerted, systematic global interdisciplinary research to improve future outcomes in autoimmune-related rheumatic conditions with multiorgan, multisystem, and cardiovascular involvement.

Cardiothoracic surgery and peripheral endovascular intervention in cardiovascular damage from a cohort of orphan rheumatological diseases-epidemiological and survival analysis.

Background: Aortic diseases in some orphan rheumatological diseases require medical, surgical or peripheral endovascular intervention because they can be catastrophic. Objectives: to analyze the main clinical and epidemiological characteristics of patients with Takayasu arteritis (TA), Marfan syndrome (MS) and similar conditions that were treated with cardiothoracic surgery and peripheral endovascular intervention. Methods: Retrospective and descriptive cohort study that included patients of any age and gender with TA (as per the criteria of the American College of Rheumatology and EULAR/PRINTO), MS (according to Ghent criteria), and similar conditions who underwent cardiothoracic surgery or peripheral endovascular intervention. Data were collected from electronic charts. Results: A total of 77 patients with TA and 135 patients with MS and similar conditions were included. The frequency of surgical or interventional requirements in patients with TA and MS/similar conditions was 77/364 (21.2%) and 135/300 (45%), respectively; such patients were followed for a median of 6 [2-12] and 3.29 (0.42-6.62) years, with (maximum follow-up range of 47 and 21.37 years, respectively). Aneurysms were present in 11 (14.3%) and 66 (48.9%) in patients with TA and MS/similar conditions, respectively. Aortic, mitral and tricuspid valve damage occurred in 8 (10.4%) patients, 4 (5.2%) patients and 1 (1.3%) patient with TA, respectively; corresponding frequencies in patients with MS/similar conditions were 98 (72.6%), 50 (37.0%) and 20 (14.8%). We identified that 20% of patients with TA died after 5.08 years (95% CI: 0.23-25.42 years) and 20 % of the patients with MS and other similar conditions died after 7.52 years (95% CI: 1.10-9.02 years). Conclusions: The frequency of surgical intervention was low in this study. Long-term prognosis is good if surgery is performed in a timely manner. Epidemiological studies provide relevant information for public health decisions related to the management of orphan rheumatological diseases.

Hyperglycemia and Loss of Redox Homeostasis in COVID-19 Patients.

The infection with SARS-CoV-2 impairs the glucose−insulin axis and this contributes to oxidative (OS) and nitrosative (NSS) stress. Here, we evaluated changes in glucose metabolism that could promote the loss of redox homeostasis in COVID-19 patients. This was comparative cohort and analytical study that compared COVID-19 patients and healthy subjects. The study population consisted of 61 COVID-19 patients with and without comorbidities and 25 healthy subjects (HS). In all subjects the plasma glucose, insulin, 8-isoprostane, Vitamin D, H2S and 3-nitrotyrosine were determined by ELISA. The nitrites (NO2−), lipid-peroxidation (LPO), total-antioxidant-capacity (TAC), thiols, glutathione (GSH) and selenium (Se) were determined by spectrophotometry. The glucose, insulin and HOMA-IR (p < 0.001), 8-isoprostanes, 3-nitrotyrosine (p < 0.001) and LPO were increased (p = 0.02) while Vitamin D (p = 0.01), H2S, thiols, TAC, GSH and Se (p < 0.001) decreased in COVID-19 patients in comparison to HS. The SARS-CoV-2 infection resulted in alterations in the glucose−insulin axis that led to hyperglycemia, hyperinsulinemia and IR in patients with and without comorbidities. These alterations increase OS and NSS reflected in increases or decreases in some oxidative markers in plasma with major impact or fatal consequences in patients that course with metabolic syndrome. Moreover, subjects without comorbidities could have long-term alterations in the redox homeostasis after infection.

Interconnection between Cardiac Cachexia and Heart Failure-Protective Role of Cardiac Obesity.

Cachexia may be caused by congestive heart failure, and it is then called cardiac cachexia, which leads to increased morbidity and mortality. Cardiac cachexia also worsens skeletal muscle degradation. Cardiac cachexia is the loss of edema-free muscle mass with or without affecting fat tissue. It is mainly caused by a loss of balance between protein synthesis and degradation, or it may result from intestinal malabsorption. The loss of balance in protein synthesis and degradation may be the consequence of altered endocrine mediators such as insulin, insulin-like growth factor 1, leptin, ghrelin, melanocortin, growth hormone and neuropeptide Y. In contrast to many other health problems, fat accumulation in the heart is protective in this condition. Fat in the heart can be divided into epicardial, myocardial and cardiac steatosis. In this review, we describe and discuss these topics, pointing out the interconnection between heart failure and cardiac cachexia and the protective role of cardiac obesity. We also set the basis for possible screening methods that may allow for a timely diagnosis of cardiac cachexia, since there is still no cure for this condition. Several therapeutic procedures are discussed including exercise, nutritional proposals, myostatin antibodies, ghrelin, anabolic steroids, anti-inflammatory substances, beta-adrenergic agonists, medroxyprogesterone acetate, megestrol acetate, cannabinoids, statins, thalidomide, proteasome inhibitors and pentoxifylline. However, to this date, there is no cure for cachexia.

Systematic review and meta-analysis of aortic valve-sparing surgery versus replacement surgery in ascending aortic aneurysms and dissection in patients with Marfan syndrome and other genetic connective tissue disorders.

BACKGROUND: Aortic aneurysm and dissection are important causes of morbimortality in patients with Marfan syndrome (MFS) and other connective tissue diseases that affect the cardiovascular tissues. Timely intervention through different surgical techniques improves the prognosis. Both sparing and replacement-type interventions of the aortic valve are used, but selection depends on the condition of the patient at the time of diagnosis, the patient's emergency condition, surgeon preference and hospital resources. Previous meta-analyses have suggested an advantage with the use of sparing-type interventions, but this finding must be updated and extended to patients with other connective tissue disorders. The objetive of this study is to evaluate the outcomes of valve-sparing root replacement versus aortic root replacement procedures in patients with MFS and similar connective tissue diseases that present with aortic aneurysm or dissection. METHODS: A systematic review of cohort studies that evaluated sparing-type (preserving, remodeling, reimplantation, Yacoub, David or Florida Sleeve) or replacement-type (repair, Bentall, Button-Bentall, composite valve graft or Cabrol) procedures in patients with Marfan, Loeys-Dietz, Beals-Hecht or Ehlers-Danlos syndromes was done. Studies were retrieved from the SCOPUS, MEDLINE, CINAHL, EMBASE and LILACS electronic databases up to January 2020 without language restrictions. Only studies that directly compared sparing- versus replacement-type procedures were included in the meta-analysis. RESULTS: A total of 33 studies (n=1,807 subjects) reported sparing-type surgical interventions and 26 studies (n=2,218 subjects) reported replacement-type surgical interventions. Pooled rates of endocarditis, thromboembolism and aneurysm were higher in replacement-type surgical intervention studies. Sixteen studies were included in the meta-analysis. Sparing-type interventions were associated with a reduced risk of endocarditis (RR =0.13, 95% CI: 0.03-0.61); however, replacement-type interventions favored freedom from valve reoperation (RR =2.39, 95% CI: 1.24-4.60). All studies were at low risk of bias. CONCLUSIONS: The choice of the best surgical technique is dependent on the type of disease (MFS or other connective tissue diseases) as well as the accompanying aortic and cardiovascular damage, since these key factors are heterogeneous. Although the results of this meta-analysis tend to show some advantages for one type of surgical intervention over the other and viceversa, the surgeon can only make the best decision during the surgical act.

Polymorphisms in TNFAIP3, but not in STAT4, BANK1, BLK, and TNFSF4, are associated with susceptibility to Takayasu arteritis.

BACKGROUND: Takayasu arteritis (TAK) is considered a rare disease characterized by nonspecific inflammation of the large arteries, especially the aorta and its major branches. Because TAK is an autoimmune disease (AD), it could share susceptibility loci with other pathologies such as systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA), among others. Widely explored polymorphisms in non-HLA genes, including TNFAIP3, STAT4, TNFSF4, BANK1, and BLK have been consistently associated with both SLE and RA, but they have not been evaluated in TAK. OBJECTIVE: The aim of our study was to investigate whether TNFAIP3, STAT4, BANK1, BLK, and TNFSF4 polymorphisms are associated with susceptibility to TAK. METHODS: The TNFAIP3 rs2230926T/G and rs5029924C/T, STAT4 rs7574865G/T, BANK1 10516487G/A, BLK rs2736340T/C, rs13277113A/G, and TNFS4 rs2205960G/T polymorphisms were genotyped in 101 cases and 276 controls by using a TaqMan SNP genotyping assay. An association analysis was performed. RESULTS: The TNFAIP3 rs2230926T/G and rs5029924C/T polymorphisms were in complete linkage disequilibrium and turned out to be risk factors for TAK (OR = 4.88, p = 0.0001). The STAT4, BANK1, BLK, and TNFSF4 polymorphisms were not associated with the disease. CONCLUSIONS: This is the first study documenting an association of TNFAIP3 rs2230926T/G and rs5029924C/T with TAK. Our results provide new information on the genetic bases of TAK.

Modulation of Renal Function in a Metabolic Syndrome Rat Model by Antioxidants in Hibiscus sabdariffa L.

Metabolic syndrome (MS) is the association of three or more pathologies among which obesity, hypertension, insulin resistance, dyslipidemia, and diabetes are included. It causes oxidative stress (OS) and renal dysfunction. Hibiscus sabdariffa L. (HSL) is a source of natural antioxidants that may control the renal damage caused by the MS. The objective of this work was to evaluate the effect of a 2% HSL infusion on renal function in a MS rat model induced by the administration of 30% sucrose in drinking water. 24 male Wistar rats were divided into 3 groups: Control rats, MS rats and MS + HSL rats. MS rats had increased body weight, systolic blood pressure, triglycerides, insulin, HOMA index, and leptin (p ≤ 0.04). Renal function was impaired by an increase in perfusion pressure in the isolated and perfused kidney, albuminuria (p ≤ 0.03), and by a decrease in clearance of creatinine (p ≤ 0.04). The activity of some antioxidant enzymes including the superoxide dismutase isoforms, peroxidases, glutathione peroxidase, glutathione-S-transferase was decreased (p ≤ 0.05). Lipoperoxidation and carbonylation were increased (p ≤ 0.001). The nitrates/nitrites ratio, total antioxidant capacity, glutathione levels and vitamin C were decreased (p ≤ 0.03). The treatment with 2% HSL reversed these alterations. The results suggest that the treatment with 2% HSL infusion protects renal function through its natural antioxidants which favor an improved renal vascular response. The infusion contributes to the increase in the glomerular filtration rate, by promoting an increase in the enzymatic and non-enzymatic antioxidant systems leading to a decrease in OS and reestablishing the normal renal function.

Oxidative Stress, Plant Natural Antioxidants, and Obesity.

Oxidative stress is important in the pathophysiology of obesity, altering regulatory factors of mitochondrial activity, modifying the concentration of inflammation mediators associated with a large number and size of adipocytes, promoting lipogenesis, stimulating differentiation of preadipocytes to mature adipocytes, and regulating the energy balance in hypothalamic neurons that control appetite. This review discusses the participation of oxidative stress in obesity and the important groups of compounds found in plants with antioxidant properties, which include (a) polyphenols such as phenolic acids, stilbenes, flavonoids (flavonols, flavanols, anthocyanins, flavanones, flavones, flavanonols, and isoflavones), and curcuminoids (b) carotenoids, (c) capsaicinoids and casinoids, (d) isothiocyanates, (e) catechins, and (f) vitamins. Examples are analyzed, such as resveratrol, quercetin, curcumin, ferulic acid, phloretin, green tea, Hibiscus Sabdariffa, and garlic. The antioxidant activities of these compounds depend on their activities as reactive oxygen species (ROS) scavengers and on their capacity to prevent the activation of NF-κB (nuclear factor κ-light-chain-enhancer of activated B cells), and reduce the expression of target genes, including those participating in inflammation. We conclude that natural compounds have therapeutic potential for diseases mediated by oxidative stress, particularly obesity. Controlled and well-designed clinical trials are still necessary to better know the effects of these compounds.

Expressão de Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade (LRP1) em Monócito em Correlação com EIMC em Pacientes Mexicanos Hipertensos / Monocyte Low-Density Lipoprotein Receptor-Related Protein 1 (LRP1) Expression Correlates with cIMT in Mexican Hypertensive Patients

Resumo Fundamento A hipertensão arterial (HTA) representa um grande fator de risco de morbidade e mortalidade cardiovascular. Ainda não se sabe que mecanismos moleculares específicos estão associados ao desenvolvimento de hipertensão essencial. Objetivo Neste trabalho, analisamos a associação entre expressão mRNA de monócito LRP1, expressão de proteína LRP1, e espessura íntima-média de carótida (EIMC) de pacientes com hipertensão essencial. Métodos A expressão mRNA de monócito LRP1 e os níveis de proteína e EIMC foram quantificados em 200 indivíduos mexicanos, sendo 91 normotensos (NT) e 109 hipertensos (HT) A significância estatística foi definida em p < 0,05. Resultados O grupo de pacientes HT tinha EIMC maior altamente significativa em comparação com os pacientes NT (p = 0,002), e isso está relacionado ao aumento na expressão mRNA de LRP1 (6,54 versus. 2,87) (p = 0,002) e expressão de proteína LRP1 (17,83 versus 6,25), respectivamente (p = 0,001). Essas diferenças foram mantidas mesmo quando dividimos nossos grupos de estudo, levando em consideração apenas aqueles que apresentavam dislipidemia na expressão de mRNA (p = 0,041) e de proteínas (p < 0,001). Também se identificou que a indução de LRP1 mediada por LRP1 em monócitos em de maneira dependente de dose e tempo, com diferença significativa em NT versus HT (0,195 ± 0,09 versus 0,226 ± 0,12, p = 0,046). Conclusão Foi encontrado um aumento em EIMC em indivíduos com hipertensão, associada a expressões de proteína LRP1 e mRNA mais altas em monócitos, independente da presença de dislipidemia em pacientes HT. Esses resultados que a upregulation de LRP1 em monócitos de pacientes hipertensos mexicanos poderia estar envolvida na diminuição da EIMC. (Arq Bras Cardiol. 2021; 116(1):56-65)

Abstract Background Arterial hypertension (HTA) represents a major risk factor for cardiovascular morbidity and mortality. It is not yet known which specific molecular mechanisms are associated with the development of essential hypertension. Objective In this study, we analyzed the association between LRP1 monocyte mRNA expression, LRP1 protein expression, and carotid intima media thickness (cIMT) of patients with essential hypertension. Methods The LRP1 monocyte mRNA expression and protein levels and cIMT were quantified in 200 Mexican subjects, 91 normotensive (NT) and 109 hypertensive (HT). Statistical significance was defined as p < 0.05. Results HT patients group had highly significant greater cIMT as compared to NT patients (p=0.002) and this correlated with an increase in the expression of LRP1 mRNA expression (6.54 vs. 2.87) (p = 0.002) and LRP1 protein expression (17.83 vs. 6.25), respectively (p = 0.001). These differences were maintained even when we divided our study groups, taking into account only those who presented dyslipidemia in both, mRNA (p = 0.041) and proteins expression (p < 0.001). It was also found that Ang II mediated LRP1 induction on monocytes in a dose and time dependent manner with significant difference in NT vs. HT (0.195 ± 0.09 vs. 0.226 ± 0.12, p = 0.046). Conclusion An increase in cIMT was found in subjects with hypertension, associated with higher mRNA and LRP1 protein expressions in monocytes, irrespective of the presence of dyslipidemias in HT patients. These results suggest that LRP1 upregulation in monocytes from Mexican hypertensive patients could be involved in the increased cIMT. (Arq Bras Cardiol. 2021; 116(1):56-65)

Lack of Association between Cytokine Genetic Polymorphisms in Takayasu's Arteritis in Mexican Patients.

Aim: To investigate the relation between polymorphisms in the interleukin 10 (IL)-10, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-ß and interferon (IFN)-γ genes and Takayasu's arteritis in the Mexican population. Methods: A case-control study was performed to investigate the associations of IL-10, TNF-α, TGF-ß and IFN-γ polymorphisms in a sample of 52 Takayasu's arteritis patients, diagnosed according to the criteria of the American College of Rheumatology and EULAR PRINTO criteria when the patients were under 18 years of age; 60 clinically healthy unrelated Mexican individuals by the 5' exonuclease TaqMan polymerase chain reaction. Polymorphic haplotypes were constructed after linkage disequilibrium analysis. Results: Significant differences were not found in the distribution for genotype and allele frequencies of the polymorphisms studied between healthy controls and Takayasu´s arteritis patients. Likewise, significant associations were not detected in the haplotype analysis with the different genes studied. Conclusions: These findings suggest that the polymorphisms in IL-10, TNF-α, TGF-ß and IFN-γ might not contribute to the susceptibility of Takayasu´s arteritis in the Mexican population.

Structural and functional role of disulphide bonds and substrate binding residues of the human beta-galactoside alpha-2,3-sialyltransferase 1 (hST3Gal1).

Overexpression of hST3Gal1 leads to hypersialylation of cell-surface glycoconjugates, a cancer-associated condition that promotes cell growth, migration and invasion. Upregulation of this enzyme in ovarian cancer is linked to cancer progression and metastasis, contributing also to chemotherapy resistance. Strategies for preventing metastasis include the inhibition of hST3Gal1, which demands structure-based studies on its strict regioselectivity and substrate/donor preference. Herein we describe the contribution of various residues constituting donor CMP-Neu5Ac and acceptor Galß1-3GalNAc-R binding sites to catalysis. Removal of hydrogen bonds and/or stacking interactions among substrates and residues Y191, Y230, N147, S148 and N170 affected the enzyme's activity to a different extent, revealing the fine control needed for an optimal catalytic performance. To gain further understanding of the correlation among structure, activity and stability, the in vitro role of hST3Gal1 disulphide bonds was analysed. As expected, disruption of the Glycosyltransferase family 29 (GT29) invariant bond C142-C281, as well as the ST3Gal1 subfamily conserved disulphide C61-C139 inactivates the enzyme. While disulphide C59-C64 is not essential for function, its absence reduces the activity (kcat) for donor and acceptor substrates to about 67 and 72%, respectively, and diminishes the enzyme's melting temperature (Tm) by 7 °C.