19 research outputs found
Circadian Variation in Metabolism and Inflammation: Role in Obesity-Induced Heart Failure with Preserved Ejection Fraction
Obesity has become a public global health problem. More than 13% of the world’s 7.8 billion people (11% of men and 15% of women) are obese, defined as having a body mass index above 30 kg/m2. In North America and several Middle Eastern Countries, more than 30% of adults are obese. The alarming problem is that children as young as twelve years of age are now becoming obese. Obesity with high-fat and high-sugar diets is a risk factor for type 2 diabetes mellitus (T2DM), hypertension and early-onset heart failure (HF) with preserved ejection fraction (HFpEF) that leads to frequent hospitalizations. It is possible that diet, inactivity and other modern lifestyle factors may have an important role in the development of heart failure, either with or without decrease in ejection fraction [1]. This mini review discusses whether circadian oscillations in metabolism and inflammation could be responsible for the time-of-day-dependence of adverse cardio-vascular events in patients with HFpEF by increasing production of cytotoxic a-dicarbonyl species methylglyoxal (MG) and by decreasing expression of the primary MG-degrading enzyme glyoxalase-1 (Glo1), respectively
A Glutathione-independent Glyoxalase of the DJ-1 Superfamily Plays an Important Role in Managing Metabolically Generated Methylglyoxal in \u3ci\u3eCandida albicans\u3c/i\u3e
Methylglyoxal is a cytotoxic reactive carbonyl compound produced by central metabolism. Dedicated glyoxalases convert methylglyoxal to D-lactate using multiple catalytic strategies. In this study, the DJ-1 superfamily member ORF 19.251/GLX3 from Candida albicans is shown to possess glyoxalase activity, making this the first demonstrated glutathione-independent glyoxalase in fungi. The crystal structure of Glx3p indicates that the protein is a monomer containing the catalytic triad Cys136- His137-Glu168. Purified Glx3p has an in vitro methylglyoxalase activity (Km = 5.5 mM andkcat = 7.8 s-1) that is significantly greater than that of more distantly related members of the DJ-1 superfamily. A close Glx3p homolog from Saccharomyces cerevisiae (YDR533C/Hsp31) also has glyoxalase activity, suggesting that fungal members of the Hsp31 clade of the DJ-1 superfamily are all probable glutathione-independent glyoxalases. A homozygous glx3 null mutant in C. albicans strain SC5314 displays greater sensitivity to millimolar levels of exogenous methylglyoxal, elevated levels of intracellular methylglyoxal, and carbon source-dependent growth defects, especially when grown on glycerol. These phenotypic defects are complemented by restoration of the wild-type GLX3 locus. The growth defect of Glx3-deficient cells in glycerol is also partially complemented by added inorganic phosphate, which is not observed for wild-type or glucose-grown cells. Therefore, C. albicans Glx3 and its fungal homologs are physiologically relevant glutathione- independent glyoxalases that are not redundant with the previously characterized glutathione-dependent GLO1/GLO2 system. In addition to its role in detoxifying glyoxals, Glx3 and its close homologs may have other important roles in stress response
Adeno-Associated Viral Transfer of Glyoxalase-1 Blunts Carbonyl and Oxidative Stresses in Hearts of Type 1 Diabetic Rats
Accumulation of methylglyoxal (MG) arising from downregulation of its primary degrading enzyme glyoxalase-1 (Glo1) is an underlying cause of diabetic cardiomyopathy (DC). This study investigated if expressing Glo1 in rat hearts shortly after the onset of Type 1 diabetes mellitus (T1DM) would blunt the development of DC employing the streptozotocin-induced T1DM rat model, an adeno-associated virus containing Glo1 driven by the endothelin-1 promoter (AAV2/9-Endo-Glo1), echocardiography, video edge, confocal imaging, and biochemical/histopathological assays. After eight weeks of T1DM, rats developed DC characterized by decreased E:A ratio, fractional shortening, and ejection fraction, and increased isovolumetric relaxation time, E: e’ ratio, and circumferential and longitudinal strains. Evoked Ca2+ transients and contractile kinetics were also impaired in ventricular myocytes. Hearts from eight weeks T1DM rats had lower Glo1 and GSH levels, elevated carbonyl/oxidative stress, microvascular leakage, inflammation, and fibrosis. A single injection of AAV2/9 Endo-Glo1 (1.7×1012 viron particles/kg) one week after onset of T1DM, potentiated GSH, and blunted MG accumulation, carbonyl/oxidative stress, microvascular leakage, inflammation, fibrosis and impairments in cardiac and myocyte functions that develop after eight weeks of T1DM. These new data indicate that preventing Glo1 downregulation by administering AAV2/9-Endo-Glo1 to rats one week after the onset of T1DM, blunted the DC that develops after eight weeks of diabetes by attenuating carbonyl/oxidative stresses, microvascular leakage, inflammation, and fibrosis
Smooth Muscle-Generated Methylglyoxal Impairs Endothelial Cell-Mediated Vasodilatation of Cerebral Microvessels in Type 1 Diabetic Rats
Background and Purpose
Endothelial cell-mediated vasodilatation of cerebral arterioles is impaired in individuals with Type 1 diabetes (T1D). This defect compromises haemodynamics and can lead to hypoxia, microbleeds, inflammation and exaggerated ischaemia-reperfusion injuries. The molecular causes for dysregulation of cerebral microvascular endothelial cells (cECs) in T1D remains poorly defined. This study tests the hypothesis that cECs dysregulation in T1D is triggered by increased generation of the mitochondrial toxin, methylglyoxal, by smooth muscle cells in cerebral arterioles (cSMCs).
Experimental Approach
Endothelial cell-mediated vasodilatation, vascular transcytosis inflammation, hypoxia and ischaemia-reperfusion injury were assessed in brains of male Sprague-Dawley rats with streptozotocin-induced diabetes and compared with those in diabetic rats with increased expression of methylglyoxal-degrading enzyme glyoxalase-I (Glo-I) in cSMCs.
Key Results
After 7–8 weeks of T1D, endothelial cell-mediated vasodilatation of cerebral arterioles was impaired. Microvascular leakage, gliosis, macrophage/neutrophil infiltration, NF-κB activity and TNF-α levels were increased, and density of perfused microvessels was reduced. Transient occlusion of a mid-cerebral artery exacerbated ischaemia-reperfusion injury. In cSMCs, Glo-I protein was decreased, and the methylglyoxal-synthesizing enzyme, vascular adhesion protein 1 (VAP-1) and methylglyoxal were increased. Restoring Glo-I protein in cSMCs of diabetic rats to control levels via gene transfer, blunted VAP-1 and methylglyoxal increases, cECs dysfunction, microvascular leakage, inflammation, ischaemia-reperfusion injury and increased microvessel perfusion.
Conclusions and Implications
Methylglyoxal generated by cSMCs induced cECs dysfunction, inflammation, hypoxia and exaggerated ischaemia-reperfusion injury in diabetic rats. Lowering methylglyoxal produced by cSMCs may be a viable therapeutic strategy to preserve cECs function and blunt deleterious downstream consequences in T1D
A Link Between Methylglyoxal and Heart Failure During HIV-1 Infection
Early-onset heart failure (HF) continues to be a major cause of morbidity and mortality in people living with human immunodeficiency virus type one (HIV-1) infection (PLWH), yet the molecular causes for this remain poorly understood. Herein NOD.Cg- PrkdcscidIl2rgtm1Wjl/SzJ humanized mice (Hu-mice), plasma from PLWH, and autopsied cardiac tissues from deceased HIV seropositive individuals were used to assess if there is a link between the glycolysis byproduct methylglyoxal (MG) and HF in the setting of HIV-1 infection. At five weeks post HIV infection, Hu-mice developed grade III-IV diastolic dysfunction (DD) with an associated two-fold increase in plasma MG. At sixteen-seventeen weeks post infection, cardiac ejection fraction and fractional shortening also declined by 26 and 35%, and plasma MG increased to four-fold higher than uninfected controls. Histopathological and biochemical analyses of cardiac tissues from Hu-mice 17 weeks post-infection affirmed MG increase with a concomitant decrease in expression of the MG-degrading enzyme glyoxalase-1 (Glo1). The endothelial cell marker CD31 was found to be lower, and coronary microvascular leakage and myocardial fibrosis were prominent. Increasing expression of Glo1 in Hu-mice five weeks post-infection using a single dose of an engineered AAV2/9 (1.7 Ă— 1012 virion particles/kg), attenuated the increases in plasma and cardiac MG levels. Increasing Glo1 also blunted microvascular leakage, fibrosis, and HF seen at sixteen weeks post-infection, without changes in plasma viral loads. In plasma fromvirally suppressed PLWH,MG was also 3.7-fold higher. In autopsied cardiac tissues from seropositive, HIV individuals with low viral log, MG was 4.2-fold higher and Glo1 was 50% lower compared to uninfected controls. These data show for the first time a causal link between accumulation of MG and HF in the setting of HIV infection
SPTBN5, Encoding the βV-Spectrin Protein, Leads to a Syndrome of Intellectual Disability, Developmental Delay, and Seizures
Whole exome sequencing has provided significant opportunities to discover novel candidate genes for intellectual disability and autism spectrum disorders. Variants in the spectrin genes SPTAN1, SPTBN1, SPTBN2, and SPTBN4 have been associated with neurological disorders; however, SPTBN5 gene-variants have not been associated with any human disorder. This is the first report that associates SPTBN5 gene variants (ENSG00000137877: c.266A>C; p.His89Pro, c.9784G>A; p.Glu3262Lys, c.933C>G; p.Tyr311Ter, and c.8809A>T; p.Asn2937Tyr) causing neurodevelopmental phenotypes in four different families. The SPTBN5-associated clinical traits in our patients include intellectual disability (mild to severe), aggressive tendencies, accompanied by variable features such as craniofacial and physical dysmorphisms, autistic behavior, and gastroesophageal reflux. We also provide a review of the existing literature related to other spectrin genes, which highlights clinical features partially overlapping with SPTBN5
The prevalence of polypharmacy and hyper-polypharmacy among middle-aged vs. older patients in Saudi Arabia: a cross-sectional study
IntroductionPolypharmacy, the use of multiple medications, is a growing concern among middle-aged and older patients, posing potential risks and challenges in healthcare management.AimThis study aimed to identify the prevalence of polypharmacy and hyper-polypharmacy among populations of middle-aged vs. older patients and identify its associated common comorbidities and prescribed medications in Qatif Central Hospital (QCH), Saudi Arabia.MethodsPatients aged 40 years or older who presented to an outpatient medical care clinic at QCH, Saudi Arabia, between 1 January and 31 December 2021 were included, and their comorbidities, prescribed medications, and recent clinical laboratory test results were collected. The Charlson comorbidity index (CCI) score was calculated to predict the risk of mortality. Logistic regression was used to compute the association between the prevalence of polypharmacy and patient characteristics. The results were presented as odds ratios (ORs) and 95% confidence intervals (95% CIs).ResultsA total of 14,081 patients were included; 31% of the cohort comprised older patients, and 66% of the cohort was identified with polypharmacy. The majority of the polymedicated patients were presented to an internal medicine care unit (34%). The prevalence of polypharmacy was positively associated with CCI (OR = 3.4, 95% CI 3.3–3.6), having a disease related to the musculoskeletal system (MSD) (OR = 4.2, 95% CI 3.8–4.7), and alimentary tract and metabolism (ATM) (OR = 3.8, 95% CI 3.4–4.2). Conversely, the prevalence of polypharmacy was negatively associated with age (OR = 0.9, 95% CI 0.89–0.91) and patients with cardiovascular diseases (OR = 0.6, 95% CI 0.5–0.7).ConclusionPolypharmacy is still an ongoing concern. Patients, particularly those with diseases related to MSD or ATM, should be considered for reviewing prescriptions by pharmacists to reduce the risk of adverse drug reactions and future consequences of polypharmacy
Assessment of self-medication practice and the potential to use a mobile app to ensure safe and effective self-medication among the public in Saudi Arabia
Background: Self-medication (SM) plays an essential role in maintaining a good quality of life for individuals. Previous studies suggested that efforts are still needed to ensure the safe practice of SM. The advances in technology and the internet have granted the availability of abundant and easily accessed medication information. However, identifying the reliability of information could be a challenge for the public. This study aimed to investigate the attitude toward SM, determinants of SM, and knowledge about medication in Saudi Arabia. Also, this study aimed to assess the willingness to use a mobile app that would be specifically designed to guide the practice of SM. Methods: A cross-sectional study was conducted in a form of an online survey among the public in Saudi Arabia. QuestionPro® platform was utilized to collect data from respondents for two months. Statistical analysis was performed using IBM® SPSS® statistics version 26. Results: A total of 1226 individuals completed the questionnaire. The prevalence of SM practice was 59%. The most frequent reason for not practicing SM was the concern about the drug safety issues (38%). Significant statistical associations were identified between SM and several demographic variables, e.g., age, gender, education, health insurance, and having a chronic illness. Most respondents (82.7%) were aware of the necessity of improving SM practice. Knowledge about different aspects of SM (e.g., proper drug selection and administration) was evaluated based on the consumer’s perspective. Our data showed that overall knowledge about SM was limited for many consumers. The assessment of the participant’s willingness to use a SM app indicated that 47.6% were interested in using such app. This willingness was significantly associated with the consumer’s attitude toward SM and being a chronically ill patient. Conclusion: SM is a common practice in Saudi Arabia. However, public awareness about SM is limited. So, implementing new strategies to enhance knowledge and ensure the safety of SM is important. A large proportion of participants were interested to use a SM app, which would improve SM practice. Therefore, we recommend developing a SM-oriented app to be used by the public in Saudi Arabia
Rosinidin Protects Streptozotocin-Induced Memory Impairment-Activated Neurotoxicity by Suppressing Oxidative Stress and Inflammatory Mediators in Rats
Background and Objectives: To assess the antioxidant and neuroprotective role of rosinidin on rat memory impairment that is induced by streptozotocin. Materials and Methods: Wistar rats were given an intraperitoneal (i.p) injection of streptozotocin (60 mg/kg) followed by treatment with rosinidin at selective doses (10 and 20 mg/kg) for 30 days. The behavioral parameters were estimated by Y-maze test and Morris water test. Biochemical parameters such as acetylcholinesterase (AChE), choline aacetyltransferase (ChAT), and nitric oxide, and antioxidants such as glutathione transferase (GSH), superoxide dismutase (SOD) IL-6, IL-10, Nrf2, and BDNF, were determined. Results: The study results revealed that rosinidin improved cognition by reverting the behavioral parameters. The treatment with rosinidin restored the antioxidant enzymes and inflammatory cytokines. Conclusions: From the results, it has been proven that rosinidin possesses antioxidant, anti-amnesic, and anti-inflammatory activity. Rosinidin improved the cognitive and behavioral deficits that were induced by streptozotocin. Furthermore, 20 mg/kg rosinidin was found to have strong protective action against streptozotocin-induced toxicity