Carvedilol improves glucose tolerance and insulin sensitivity in treatment of adrenergic overdrive in high fat diet-induced obesity in mice

Next-Generation Carbazole-Linked 1,2,4-Triazole-Thione Derivatives: Strategic Design, Synthesis, Molecular Docking, and Evaluation of Antidiabetic Potential

Currently, available therapies for diabetes cannot achieve normal sugar values in a high percentage of treated patients. This work synthesized a series of carbazole-triazole-thione derivatives, and their potential antidiabetic activity was investigated against the key diabetic enzymes α-amylase and glycosidase. Normal human hepatic stellate cells (LX-2) were employed to assess their cytotoxicity and safety, followed by in vivo testing to investigate the hypoglycemic effect of the most promising agent. As a result, a set of 18 carbazole-1,2,4-triazole-thione derivatives were synthesized. Seven structures demonstrated potential inhibitory activity against α-amylase enzyme, with IC50 lower than 6.4 μM. Among them, compounds C5f, C5o, and C5r exhibited the highest potency, with IC50 values of 0.56, 0.53, and 0.97 μM, respectively, compared to the well-known α-amylase inhibitor acarbose, which has an IC50 value of 5.31 μM. Exploring the inhibition potency of these series against α-glucosidase enzyme revealed that C5f and C5r compounds act as moderate inhibitors, with IC50 values of 11.03 and 13.76 μM, respectively. Moreover, at 100 μM concentration, most of the evaluated compounds showed negligible cytotoxic effect against LX-2 cell lines, particularly compounds C5o and C5s, that demonstrated lower cytotoxic activity by 3-fold compared to the positive control 5-Flururicle (cell viability 13.45%). Thus, the C5f compound was selected for in vivo evaluation, and after administering five doses of this compound (10 mg/kg) to group III of mice, a significant reduction in glucose concentration was observed, bringing it down from 290.54 to 216.15 mg/dL, in comparison with the control group which did not show a reduction in blood glucose level. These observed in vitro and in vivo results were upheld by performing a set of chemoinformatic studies that elucidated the binding interactions of the most active derivatives within the enzyme's active site and highlighted the critical roles of both the 1,2,4-triazole-3-thione and carbazole scaffolds in these interactions. Finally, the drug-likeness profiles of our carbazole-triazole-thione derivatives suggest their potential as candidates for further in vivo studies and clinical trials.

Overnutrition causes insulin resistance and metabolic disorder through increased sympathetic nervous system activity

The mechanisms underlying obesity-induced insulin resistance remain incompletely understood, as impaired cellular insulin signaling, traditionally considered the primary driver of insulin resistance, does not always accompany impaired insulin action. Overnutrition rapidly increases plasma norepinephrine (NE), suggesting overactivation of the sympathetic nervous system (SNS). However, the role of the SNS in obesity is controversial, as both increased and decreased SNS activity (SNA) have been reported. Here, we show that reducing catecholamine (CA) release from the SNS protects against overnutrition-induced insulin resistance as well as hyperglucagonemia, adipose tissue dysfunction, and fatty liver disease, as we demonstrate utilizing a mouse model of inducible and peripherally restricted deletion of tyrosine hydroxylase (th; THΔper). A key mechanism through which heightened SNA induces insulin resistance is by triggering adipose tissue lipolysis. Increased SNA emerges as a critical driver in the pathogenesis of overnutrition-induced insulin resistance and metabolic disease independent of cellular insulin signaling.

Effects of stress hyperglycemia ratio upon long-lasting prognosis in coronary artery disease patients with or lacking chronic renal impairment: findings from a Chinese multi-center observational study

BACKGROUND

Lately, numerous researches have portrayed stress hyperglycemia ratio (SHR) is predominantly connected with short-term adverse prognosis among individuals who have acute coronary syndrome. Nevertheless, the relation of SHR with prolonged effects and the value of SHR in predicting in coronary artery disease (CAD) patients with or lacking chronic kidney disease (CKD) remain unclear. The present study was designed to elucidate the relation of SHR with prolonged prognosis and the value of SHR in predicting the long-term all-cause and cardiovascular death of CAD patients with CKD or non-CKD.

METHODS

We assessed 45,780 adults with CAD from a Chinese multi-center registry. SHR was computed via a formula [SHR = (admission glucose) (mmol/L) / (1.59 * HbA1c [%] - 2.59)]. Based on the presence or absence of CKD and SHR levels, patients were categorized into four groups. Long-term all-cause and cardiovascular mortality were the primary endpoints. The Kaplan-Meier method, restricted cubic spline (RCS), cox regression analysis, subgroups analysis, and sensitivity analysis were employed to estimate the connection between SHR and all-cause as well as cardiovascular mortality.

RESULTS

During a median follow-up of 5.2 years ( IQR 3.0-8.0), among 45,780 CAD patients (mean age [SD]: 62.8 ± 10.6 years; 23.9% female), the number of all-cause deaths was 7144(15.6%), and cardiovascular-related deaths was 3255 (7.1%). In cohorts with CKD, patients with high SHR had higher all-cause mortality (30.2% vs. 27.6%; adjusted hazard ratio HR 1.13, 95% CI 1.04-1.22; P = 0.003) and cardiovascular mortality (18.2% vs. 15.6%; HR adjusted 1.17, 95% CI 1.06-1.30; P = 0.002) compared to the individuals in low SHR. However, this was not the case in CAD cohorts without CKD [all-cause mortality (12.9% vs. 11.9%; HR adjusted 1.04, 95%CI 0.98-1.10, P = 0.206); cardiovascular mortality (5.1% vs. 4.4%; HR adjusted 1.09, 95%CI 0.99-1.20, P = 0.084)]. KM analysis revealed that high SHR is linked with all-cause mortality [CKD (log-rank P < 0.001); no-CKD (log-rank P = 0.024)] and cardiovascular mortality [CKD (log-rank P < 0.001); no-CKD (log-rank P = 0.01)] in CAD patients with or without CKD. RCS demonstrated that the relation between SHR and all-cause mortality was U-shaped after full modification, which was shown for CKD patients (P for non-linearity = 0.003) and also for patients without CKD (P for non-linearity = 0.001). Analogous effects were discovered for cardiovascular mortality, which was the case for CKD patients (P for non-linearity < 0.001) and also for patients without CKD (P for non-linearity = 0.001).

CONCLUSIONS

Among patients with CAD, an elevated stress hyperglycemia ratio (SHR) is implicated in a heightened risk of long-term outcomes, particularly in those with CKD. This signifies that SHR might have a latent function in the cardiovascular risk categorization of the CAD population.

From "contraindicated" to "first line" - Current mechanistic insights beyond canonical β-receptor signaling

β-blockers are a solid pillar in the treatment of cardiovascular diseases. However, they are highly discussed regarding effectiveness for certain indications and side-effects. Even though there are up to 20 licensed compounds, only four are used for heart failure (HF) therapy. On the receptor level several key characteristics seem to influence the clinical outcome: subtype selectivity, antagonistic vs (inverse/biased) agonistic properties and -in particular- ancillary capacities. On a molecular level, divergent and novel signaling patterns are being identified and extra-cardiac effects on e.g. inflammation, metabolism and oxidative stress are highlighted. This review discusses different well-known and newly discovered characteristics that need to be considered for HF therapy and in the context of co-morbidities.

The Role of Catecholamines in the Pathogenesis of Diseases and the Modified Electrodes for Electrochemical Detection of Catecholamines: A Review

Catecholamines (CAs), which include adrenaline, noradrenaline, and dopamine, are neurotransmitters and hormones that critically regulate the cardiovascular system, metabolism, and stress response in the human body. The abnormal levels of these molecules can lead to the development of various diseases, including pheochromocytoma and paragangliomas, Alzheimer's disease, and Takotsubo cardiomyopathy. Due to their low cost, high sensitivity, flexible detection strategies, ease of integration, and miniaturization, electrochemical techniques have been extensively employed in the detection of CAs, surpassing traditional analytical methods. Electrochemical detection of CAs in real samples is challenging due to the tendency of poisoning electrode. Chemically modified electrodes have been widely used to solve the problems of poor sensitivity and selectivity faced by bare electrodes. There are a few articles that provide an overview of electrochemical detection and efficient enrichment of CAs, but there is a dearth of updates on the role of CAs in the pathogenesis of diseases. Additionally, there is still a lack of systematic synthesis with a focus on modified electrodes for electrochemical detection. Thus, this review provides a summary of the recent clinical pathogenesis of CAs and the modified electrodes for electrochemical detection of CAs published between 2017 and 2022. Moreover, challenges and future perspectives are also highlighted. This work is expected to provide useful guidance to researchers entering this interdisciplinary field, promoting further development of CAs pathogenesis, and developing more novel chemically modified electrodes for the detection of CAs.

Obesity Is a Major Determinant of Impaired Cardiac Energy Metabolism in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a major health problem with limited treatment options. Although optimizing cardiac energy metabolism is a potential approach to treating heart failure, it is poorly understood what alterations in cardiac energy metabolism actually occur in HFpEF. To determine this, we used mice in which HFpEF was induced using an obesity and hypertension HFpEF protocol for 10 weeks. Next, carvedilol, a third-generation β-blocker and a biased agonist that exhibits agonist-like effects through β arrestins by activating extracellular signal-regulated kinase, was used to decrease one of these parameters, namely hypertension. Heart function was evaluated by invasive pressure-volume loops and echocardiography as well as by ex vivo working heart perfusions. Glycolysis and oxidation rates of glucose, fatty acids, and ketones were measured in the isolated working hearts. The development of HFpEF was associated with a dramatic decrease in cardiac glucose oxidation rates, with a parallel increase in palmitate oxidation rates. Carvedilol treatment decreased the development of HFpEF but had no major effect on cardiac energy substrate metabolism. Carvedilol treatment did increase the expression of cardiac β arrestin 2 and proteins involved in mitochondrial biogenesis. Decreasing bodyweight in obese HFpEF mice increased glucose oxidation and improved heart function. This suggests that the dramatic energy metabolic changes in HFpEF mice hearts are primarily due to the obesity component of the HFpEF model. SIGNIFICANCE STATEMENT: Metabolic inflexibility occurs in heart failure with preserved ejection fraction (HFpEF) mice hearts. Lowering blood pressure improves heart function in HFpEF mice with no major effect on energy metabolism. Between hypertension and obesity, the latter appears to have the major role in HFpEF cardiac energetic changes. Carvedilol increases mitochondrial biogenesis and overall energy expenditure in HFpEF hearts.

Loss of cAMP Signaling in CD11c Immune Cells Protects Against Diet-Induced Obesity

In obesity, CD11c+ innate immune cells are recruited to adipose tissue and create an inflammatory state that causes both insulin and catecholamine resistance. We found that ablation of Gnas, the gene that encodes Gαs, in CD11c expressing cells protects mice from obesity, glucose intolerance, and insulin resistance. Transplantation studies showed that the lean phenotype was conferred by bone marrow-derived cells and did not require adaptive immunity. Loss of cAMP signaling was associated with increased adipose tissue norepinephrine and cAMP signaling, and prevention of catecholamine resistance. The adipose tissue had reduced expression of catecholamine transport and degradation enzymes, suggesting that the elevated norepinephrine resulted from decreased catabolism. Collectively, our results identified an important role for cAMP signaling in CD11c+ innate immune cells in whole-body metabolism by controlling norepinephrine levels in white adipose tissue, modulating catecholamine-induced lipolysis and increasing thermogenesis, which, together, created a lean phenotype.

ARTICLE HIGHLIGHTS

We undertook this study to understand how immune cells communicate with adipocytes, specifically, whether cAMP signaling in the immune cell and the adipocyte are connected. We identified a reciprocal interaction between CD11c+ innate immune cells and adipocytes in which high cAMP signaling in the immune cell compartment induces low cAMP signaling in adipocytes and vice versa. This interaction regulates lipolysis in adipocytes and inflammation in immune cells, resulting in either a lean, obesity-resistant, and insulin-sensitive phenotype, or an obese, insulin-resistant phenotype.

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

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

Emerging role of substance and energy metabolism associated with neuroendocrine regulation in tumor cells

Cancer is the second most common cause of mortality in the world. One of the unresolved difficult pathological mechanism issues in malignant tumors is the imbalance of substance and energy metabolism of tumor cells. Cells maintain life through energy metabolism, and normal cells provide energy through mitochondrial oxidative phosphorylation to generate ATP, while tumor cells demonstrate different energy metabolism. Neuroendocrine control is crucial for tumor cells' consumption of nutrients and energy. As a result, better combinatorial therapeutic approaches will be made possible by knowing the neuroendocrine regulating mechanism of how the neuroendocrine system can fuel cellular metabolism. Here, the basics of metabolic remodeling in tumor cells for nutrients and metabolites are presented, showing how the neuroendocrine system regulates substance and energy metabolic pathways to satisfy tumor cell proliferation and survival requirements. In this context, targeting neuroendocrine regulatory pathways in tumor cell metabolism can beneficially enhance or temper tumor cell metabolism and serve as promising alternatives to available treatments.

Carbazoles: Role and Functions in Fighting Diabetes

Carbazole derivatives have gained a lot of attention in medicinal chemistry over the last few decades due to their wide range of biological and pharmacological properties, including antibacterial, antitumor, antioxidant, and anti-inflammatory activities. The therapeutic potential of natural, semi-synthetic or synthetic carbazole-containing molecules has expanded considerably owing to their role in the pathogenesis and development of diabetes. Several studies have demonstrated the ability of carbazole derivatives to reduce oxidative stress, block adrenergic hyperactivation, prevent damage to pancreatic cells and modulate carbohydrate metabolism. In this survey, we summarize the latest advances in the synthetic and natural carbazole-containing compounds involved in diabetes pathways.

Modulation of Reactive Oxygen Species Homeostasis as a Pleiotropic Effect of Commonly Used Drugs

Age-associated diseases represent a growing burden for global health systems in our aging society. Consequently, we urgently need innovative strategies to counteract these pathological disturbances. Overwhelming generation of reactive oxygen species (ROS) is associated with age-related damage, leading to cellular dysfunction and, ultimately, diseases. However, low-dose ROS act as crucial signaling molecules and inducers of a vaccination-like response to boost antioxidant defense mechanisms, known as mitohormesis. Consequently, modulation of ROS homeostasis by nutrition, exercise, or pharmacological interventions is critical in aging. Numerous nutrients and approved drugs exhibit pleiotropic effects on ROS homeostasis. In the current review, we provide an overview of drugs affecting ROS generation and ROS detoxification and evaluate the potential of these effects to counteract the development and progression of age-related diseases. In case of inflammation-related dysfunctions, cardiovascular- and neurodegenerative diseases, it might be essential to strengthen antioxidant defense mechanisms in advance by low ROS level rises to boost the individual ROS defense mechanisms. In contrast, induction of overwhelming ROS production might be helpful to fight pathogens and kill cancer cells. While we outline the potential of ROS manipulation to counteract age-related dysfunction and diseases, we also raise the question about the proper intervention time and dosage.

Acute and chronic metabolic effects of carvedilol in high-fructose, high-fat diet-fed mice: implication of β-arrestin2 pathway

We aimed to investigate the acute and chronic effects of carvedilol on insulin resistance in high-fructose, high-fat diet (HFrHFD) - fed mice and the implication of the β-arrestin2 pathway. The acute effect of carvedilol (10 mg/kg, i.p.) on glucose tolerance and hepatic lipid signaling in normal and insulin resistant mice was investigated. Then, the chronic effect of carvedilol on insulin resistance and dyslipidemia in HFrHFD-fed mice was examined. Changes in β-arrestin2 and its downstream signals in liver, skeletal muscle, and adipose tissue were measured. This involved measuring phosphatidylinositol 4,5-bisphosphate (PIP2) and diacylglycerol (DAG) levels and protein kinase B (AKT) activity. Carvedilol acutely reduced fasting blood glucose levels in both normal and insulin resistant mice without significantly affecting the glucose tolerance. These acute effects were associated with increased hepatic PIP2 but decreased hepatic DAG levels. Chronic administration of carvedilol significantly ameliorated insulin resistance and dyslipidemia in HFrHFD-fed mice. These chronic effects were associated with increased β-arrestin2, PIP2, and AKT activity levels but decreased DAG levels in the classical insulin target tissues. In conclusion, carvedilol acutely maintains glucose homeostasis and chronically ameliorates insulin resistance and dyslipidemia in HFrHFD-fed mice. The insulin sensitizing effects of carvedilol are highly correlated with the upregulation of β-arrestin2 pathway.

Mentha cordifolia Leaf Extract Improves Hepatic Glucose and Lipid Metabolism in Obese Mice Fed with High-Fat Diet

Mentha cordifolia (MC) is a popular herb used to flavor food in Thailand that exhibits several biological effects. The present study aimed to determine the role of MC in regulating glucose and lipid metabolism in mice fed a high-fat diet (HFD). ICR obese mice were fed an HFD (45 kcal% lard fat) for 12 weeks, with MC (100 and 200 mg/kg/d) treatment from Week 7. After treatment with MC for 6 weeks, mice showed significantly lower rates of hyperglycemia, hyperinsulinemia, hyperleptinemia, and hyperlipidemia, and increased amounts of serum adiponectin. Furthermore, in mice treated with MC, serum interleukin-6 and tumor necrosis factor alpha were significantly inhibited and liver histology results showed decreased lipid accumulation and liver triglyceride content vs. untreated mice. In addition, MC treatment was associated with smaller fat cells and lower gene expression of liver sterol regulatory element binding protein 1c, acetyl-CoA carboxylase, and fatty acid synthase. However, MC treatment was associated with higher carnitine palmitoyltransferase 1a gene expression and significantly higher rates of adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in liver, but lower levels of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. These results indicate MC regulates glucose and lipid metabolism in a HFD-induced obese mouse model, possibly via activation of AMPK signaling pathway.

Immunity and the carotid body: implications for metabolic diseases

Neuro-immune communication has gained enormous interest in recent years due to increasing knowledge of the way in which the brain coordinates functional alterations in inflammatory and autoimmune responses, and the mechanisms of neuron-immune cell interactions in the context of metabolic diseases such as obesity and type 2 diabetes. In this review, we will explain how this relationship between the nervous and immune system impacts the pro- and anti-inflammatory pathways with specific reference to the hypothalamus-pituitary-adrenal gland axis and the vagal reflex and will explore the possible involvement of the carotid body (CB) in the neural control of inflammation. We will also highlight the mechanisms of vagal anti-inflammatory reflex control of immunity and metabolism, and the consequences of functional disarrangement of this reflex in settlement and development of metabolic diseases, with special attention to obesity and type 2 diabetes. Additionally, the role of CB in the interplay between metabolism and immune responses will be discussed, with specific reference to the different stimuli that promote CB activation and the balance between sympathetic and parasympathetic in this context. In doing so, we clarify the multivarious neuronal reflexes that coordinate tissue-specific responses (gut, pancreas, adipose tissue and liver) critical to metabolic control, and metabolic disease settlement and development. In the final section, we will summarize how electrical modulation of the carotid sinus nerve may be utilized to adjust these reflex responses and thus control inflammation and metabolic diseases, envisioning new therapeutics horizons.

Effects of lipid metabolism on mouse incisor dentinogenesis

Tooth formation can be affected by various factors, such as oral disease, drug administration, and systemic illness, as well as internal conditions including dentin formation. Dyslipidemia is an important lifestyle disease, though the relationship of aberrant lipid metabolism with tooth formation has not been clarified. This study was performed to examine the effects of dyslipidemia on tooth formation and tooth development. Dyslipidemia was induced in mice by giving a high-fat diet (HFD) for 12 weeks. Additionally, LDL receptor-deficient (Ldlr^−/−) strain mice were used to analyze the effects of dyslipidemia and lipid metabolism in greater detail. In the HFD-fed mice, incisor elongation was decreased and pulp was significantly narrowed, while histological findings revealed disappearance of predentin. In Ldlr^−/− mice fed regular chow, incisor elongation showed a decreasing trend and pulp a narrowing trend, while predentin changes were unclear. Serum lipid levels were increased in the HFD-fed wild-type (WT) mice, while Ldlr^−/− mice given the HFD showed the greatest increase. These results show important effects of lipid metabolism, especially via the LDL receptor, on tooth homeostasis maintenance. In addition, they suggest a different mechanism for WT and Ldlr^−/− mice, though the LDL receptor pathway may not be the only factor involved.