Editorial: sulfonylureas differ in effects on ischemic preconditioning--is it time to retire glyburide?

NLRP3 Inflammasome Inhibitors for Antiepileptogenic Drug Discovery and Development

Epilepsy is one of the most prevalent and serious brain disorders and affects over 70 million people globally. Antiseizure medications (ASMs) relieve symptoms and prevent the occurrence of future seizures in epileptic patients but have a limited effect on epileptogenesis. Addressing the multifaceted nature of epileptogenesis and its association with the Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated neuroinflammation requires a comprehensive understanding of the underlying mechanisms of these medications for the development of targeted therapeutic strategies beyond conventional antiseizure treatments. Several types of NLRP3 inhibitors have been developed and their effect has been validated both in in vitro and in vivo models of epileptogenesis. In this review, we discuss the advances in understanding the regulatory mechanisms of NLRP3 activation as well as progress made, and challenges faced in the development of NLRP3 inhibitors for the treatment of epilepsy.

Recent Progress and Prospects of Small Molecules for NLRP3 Inflammasome Inhibition

NLRP3 inflammasome is a multiprotein complex involved in host immune response─which exerts various biological effects by mediating the maturation and secretion of IL-1β and IL-18─and pyroptosis. However, its aberrant activation could cause amplification of inflammatory effects, thereby triggering a range of ailments, including Alzheimer's disease, Parkinson's disease, rheumatoid arthritis, gout, type 2 diabetes mellitus, and cancer. For the past few years, as an attractive anti-inflammatory target, NLRP3-targeting small-molecule inhibitors have been widely reported by both the academic and the industrial communities. In order to deeply understand the advancement of NLRP3 inflammasome inhibitors, we provide comprehensive insights and commentary on drugs currently under clinical investigation, as well as other NLRP3 inflammasome inhibitors from a chemical structure point of view, with an aim to provide new insights for the further development of clinical drugs for NLRP3 inflammasome-mediated diseases.

The trigger for pancreatic disease: NLRP3 inflammasome

NLRP3 inflammasome is a multiprotein complex expressed in a variety of cells to stimulate the production of inflammatory factors. Activation of NLRP3 inflammasome depends on a complex regulatory mechanism, and its pro-inflammatory function plays an important role in pancreatic diseases. In this literature review, we summarize the activation mechanism of NLRP3 and analyze its role in each of the four typical pancreatic diseases. Through this article, we provide a relatively comprehensive summary to the researchers in this field, and provide some targeted therapy routes.

The mechanism of NLRP3 inflammasome activation and its pharmacological inhibitors

NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) is a cytosolic pattern recognition receptor (PRR) that recognizes multiple pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Once activated, NLRP3 initiates the inflammasome assembly together with the adaptor ASC and the effector caspase-1, leading to caspase-1 activation and subsequent cleavage of IL-1β and IL-18. Aberrant NLRP3 inflammasome activation is linked with the pathogenesis of multiple inflammatory diseases, such as cryopyrin-associated periodic syndromes, type 2 diabetes, non-alcoholic steatohepatitis, gout, and neurodegenerative diseases. Thus, NLRP3 is an important therapeutic target, and researchers are putting a lot of effort into developing its inhibitors. The review summarizes the latest advances in the mechanism of NLRP3 inflammasome activation and its pharmacological inhibitors.

Pyroptosis in bone loss

Pyroptosis could be responsible for the bone loss from bone metabolic diseases, leading to the negative impact on people's health and life. It has been shown that osteoclasts, osteoblasts, macrophages, chondrocytes, periodontal and gingival cells may be involved in bone loss linked with pyroptosis. So far, the involved mechanisms have not been fully elucidated. In this review, we introduced the related cells involved in the pyroptosis associated with bone loss and summarized the role of these cells in the bone metabolism during the process of pyroptosis. We also discuss the clinical potential of targeting mechanisms in the osteoclasts, osteoblasts, macrophages, chondrocytes, periodontal and gingival cells touched upon pyroptosis to treat bone loss from bone metabolic diseases as well as the challenges of avoiding potential side effects and producing efficient treatment methods.

New insights into the regulatory roles of glutathione in NLRP3-inflammasome-mediated immune and inflammatory responses

Glutathione (GSH) is the most abundant non-protein thiol (-SH) in mammalian cells. Its synthesis and metabolism serve to maintain cellular reduction-oxidation (redox) homeostasis, which is important for multiple cellular processes including proliferation, differentiation, and death. An accumulating body of evidence suggests that the essential roles of GSH extended far beyond its oxidant and electrophile scavenger activities and regulatory role in the lifespan of cells. Recent findings revealed that altered GSH levels are closely associated with a wide range of pathologies including bacterial and viral infections, neurodegenerative diseases, and autoimmune disorders, all of which are also characterized by aberrant activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome. As a result of these findings, GSH was assigned a central role in influencing the activation of the NLRP3 inflammasome. To expand on our recent advances in understanding this process, we discuss here the emerging roles of GSH in activation of the NLRP3 inflammasome, and the therapeutic potential of GSH in its associated pathologies.

Regulation of the NLRP3 Inflammasome by Post-Translational Modifications and Small Molecules

Inflammation is a host protection mechanism that eliminates invasive pathogens from the body. However, chronic inflammation, which occurs repeatedly and continuously over a long period, can directly damage tissues and cause various inflammatory and autoimmune diseases. Pattern recognition receptors (PRRs) respond to exogenous infectious agents called pathogen-associated molecular patterns and endogenous danger signals called danger-associated molecular patterns. Among PRRs, recent advancements in studies of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome have established its significant contribution to the pathology of various inflammatory diseases, including metabolic disorders, immune diseases, cardiovascular diseases, and cancer. The regulation of NLRP3 activation is now considered to be important for the development of potential therapeutic strategies. To this end, there is a need to elucidate the regulatory mechanism of NLRP3 inflammasome activation by multiple signaling pathways, post-translational modifications, and cellular organelles. In this review, we discuss the intracellular signaling events, post-translational modifications, small molecules, and phytochemicals participating in the regulation of NLRP3 inflammasome activation. Understanding how intracellular events and small molecule inhibitors regulate NLRP3 inflammasome activation will provide crucial information for elucidating the associated host defense mechanism and the development of efficient therapeutic strategies for chronic diseases.

Emerging role of IL-6 and NLRP3 inflammasome as potential therapeutic targets to combat COVID-19: Role of lncRNAs in cytokine storm modulation

The world has witnessed a high morbidity and mortality caused by SARS-CoV-2, and global death toll is still rising. Exaggerated inflammatory responses are thought to be more responsible for infiltrated immune cells accumulation, organ damage especially lung, dyspnea, and respiratory failure rather than direct effect of viral replication. IL-6 and NLRP3 inflammasome are the major immune components in immune responses stimulation upon pathogen infection. It's noteworthy that the function and expression of these components are remarkably influenced by non-coding RNAs including long non-coding RNAs. Given the potential role of these components in organ damage and pathological manifestations of patients infected with COVID-19, their blockage might be a hopeful and promising treatment strategy. Notably, more study on long non-coding RNAs involved in inflammatory responses could elevate the efficacy of anti-inflammatory therapy. In this review we discuss the potential impact of IL-6 and NLRP3 inflammasome blocker drugs on inflammatory responses, viral clearance, and pathological and clinical manifestations. Collectively, anti-inflammatory strategy might pave the way to diminish clinical and pathological manifestations and thereby discharging patients infected with COVID-19 from hospital.

Co-administration of prazosin and propranolol with glibenclamide improves anti-oxidant defense system in endothelial tissue of streptozotocin-induced diabetic Wistar rats

Background Due to increasing prevalence of diabetes and associated endothelial dysfunction, this study was carried out to investigate the effects of co-administration of adrenoceptor blockers (prazosin and propranolol) and glibenclamide on plasma biomarkers of endothelial functions in diabetic rats. Methods Experiments were carried out on 35 male Wistar rats (170-200 g). They were divided into seven groups (n=5) as follows: normal control, diabetic control, diabetic + glibenclamide (GLB-5mg/kg/day), diabetic+ prazosin (PRZ-0.5 mg/kg/day), diabetic + PRZ + GLB, diabetic + propranolol (PRP-10 mg/kg/day), diabetes + PRP + GLB. Experimental diabetes was induced with streptozotocin (60 mg/kg) and drugs were administered orally for 3 weeks. Blood pressure was measured and animals were sacrificed afterwards. Blood samples were collected by cardiac puncture, and major marker of endothelial functions, nitric oxide derivatives (NOx), as well as superoxide dismutase (SOD) and malondialdehyde (MDA) were measured on the plasma. The aorta was harvested for histological examination. Data were subjected to descriptive statistics and analysed using ANOVA at α 0.05. Results There was a significant increase in levels of NOx and SOD, and a decrease in MDA level in diabetic treated groups compared to diabetic control. Mean blood pressure increased in diabetic control and diabetic + GLB group when compared with normal control, while it was mildly reduced in diabetic group treated with PRZ and PRP, and co-administered GLB. More so, Aorta histology was altered in diabetic control groups when compared with normal control and all diabetic treated groups. Conclusions Results from this study suggest that PRZ, PRP, and GLB (singly and in combined therapy) could have a restorative effect on endothelial functions in diabetes.

Inflammasomes in neuroinflammatory and neurodegenerative diseases

Neuroinflammation and neurodegeneration often result from the aberrant deposition of aggregated host proteins, including amyloid‐β, α‐synuclein, and prions, that can activate inflammasomes. Inflammasomes function as intracellular sensors of both microbial pathogens and foreign as well as host‐derived danger signals. Upon activation, they induce an innate immune response by secreting the inflammatory cytokines interleukin (IL)‐1β and IL‐18, and additionally by inducing pyroptosis, a lytic cell death mode that releases additional inflammatory mediators. Microglia are the prominent innate immune cells in the brain for inflammasome activation. However, additional CNS‐resident cell types including astrocytes and neurons, as well as infiltrating myeloid cells from the periphery, express and activate inflammasomes. In this review, we will discuss current understanding of the role of inflammasomes in common degenerative diseases of the brain and highlight inflammasome‐targeted strategies that may potentially treat these diseases.

Glyburide inhibits the bone resorption induced by traumatic occlusion in rats

OBJECTIVE

To examine whether glyburide inhibits bone destruction caused by traumatic occlusion in a rat occlusal trauma model.

BACKGROUND

Excessive mechanical stress, such as traumatic occlusion, induces expression of IL-1β and may be involved in bone resorption. NLRP3 inflammasomes have been linked to IL-1β expression, but it is currently unclear whether glyburide, the inhibiter of NLRP3 inflammasome, suppresses occlusal trauma in rats.

METHODS

Male SD rats aged 7 weeks were used. In the trauma group, the occlusal surface of the maxillary first right molar was raised by attaching a metal wire to apply occlusal trauma to the mandibular first right molar. In the trauma + glyburide group, the NLRP3 inhibitor glyburide was administered orally every 24 hours from 1 day before induction of occlusal trauma. Rats were euthanized after 5 or 10 days, and the maxillary first molars were harvested with the adjacent tissues for histopathological investigation. Immunohistochemical expression of IL-1β, NLRP3, and RANKL was also assessed.

RESULTS

On day 5, bone resorption was significantly greater in the trauma group compared with the control group or the trauma + glyburide group, and there were significantly higher numbers of osteoclasts and cells positive for IL-1β, NLRP3, and RANKL in the trauma group.

CONCLUSION

In this study, glyburide inhibits bone resorption by traumatic occlusion in rats. It suggests that the NLRP3/IL-1β pathway might be associated with bone resorption induced by traumatic occlusion.

Mechanisms of Endothelial Dysfunction in Pre-eclampsia and Gestational Diabetes Mellitus: Windows Into Future Cardiometabolic Health?

Placental insufficiency and adipose tissue dysregulation are postulated to play key roles in the pathophysiology of both pre-eclampsia (PE) and gestational diabetes mellitus (GDM). A dysfunctional release of deleterious signaling motifs can offset an increase in circulating oxidative stressors, pro-inflammatory factors and various cytokines. It has been previously postulated that endothelial dysfunction, instigated by signaling from endocrine organs such as the placenta and adipose tissue, may be a key mediator of the vasculopathy that is evident in both adverse obstetric complications. These signaling pathways also have significant effects on long term maternal cardiometabolic health outcomes, specifically cardiovascular disease, hypertension, and type II diabetes. Recent studies have noted that both PE and GDM are strongly associated with lower maternal flow-mediated dilation, however the exact pathways which link endothelial dysfunction to clinical outcomes in these complications remains in question. The current diagnostic regimen for both PE and GDM lacks specificity and consistency in relation to clinical guidelines. Furthermore, current therapeutic options rely largely on clinical symptom control such as antihypertensives and insulin therapy, rather than that of early intervention or prophylaxis. A better understanding of the pathogenic origin of these obstetric complications will allow for more targeted therapeutic interventions. In this review we will explore the complex signaling relationship between the placenta and adipose tissue in PE and GDM and investigate how these intricate pathways affect maternal endothelial function and, hence, play a role in acute pathophysiology and the development of future chronic maternal health outcomes.

Pharmacological Inhibitors of the NLRP3 Inflammasome

Inflammasomes play a crucial role in innate immunity by serving as signaling platforms which deal with a plethora of pathogenic products and cellular products associated with stress and damage. By far, the best studied and most characterized inflammasome is NLRP3 inflammasome, which consists of NLRP3 (nucleotide-binding domain leucine-rich repeat (NLR) and pyrin domain containing receptor 3), ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain), and procaspase-1. Activation of NLRP3 inflammasome is mediated by highly diverse stimuli. Upon activation, NLRP3 protein recruits the adapter ASC protein, which recruits the procaspase-1 resulting in its cleavage and activation, inducing the maturation, and secretion of inflammatory cytokines and pyroptosis. However, aberrant activation of the NLRP3 inflammasome is implicated in various diseases including diabetes, atherosclerosis, metabolic syndrome, cardiovascular, and neurodegenerative diseases; raising a tremendous clinical interest in exploring the potential inhibitors of NLRP3 inflammasome. Recent investigations have disclosed various inhibitors of the NLRP3 inflammasome pathway which were validated through in vitro studies and in vivo experiments in animal models of NLRP3-associated disorders. Some of these inhibitors directly target the NLRP3 protein whereas some are aimed at other components and products of the inflammasome. Direct targeting of NLRP3 protein can be a better choice because it can prevent off target immunosuppressive effects, thus restrain tissue destruction. This paper will review the various pharmacological inhibitors of the NLRP3 inflammasome and will also discuss their mechanism of action.

Pharmacological Inhibitors of the NLRP3 Inflammasome

Inflammasomes play a crucial role in innate immunity by serving as signaling platforms which deal with a plethora of pathogenic products and cellular products associated with stress and damage. By far, the best studied and most characterized inflammasome is NLRP3 inflammasome, which consists of NLRP3 (nucleotide-binding domain leucine-rich repeat (NLR) and pyrin domain containing receptor 3), ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain), and procaspase-1. Activation of NLRP3 inflammasome is mediated by highly diverse stimuli. Upon activation, NLRP3 protein recruits the adapter ASC protein, which recruits the procaspase-1 resulting in its cleavage and activation, inducing the maturation, and secretion of inflammatory cytokines and pyroptosis. However, aberrant activation of the NLRP3 inflammasome is implicated in various diseases including diabetes, atherosclerosis, metabolic syndrome, cardiovascular, and neurodegenerative diseases; raising a tremendous clinical interest in exploring the potential inhibitors of NLRP3 inflammasome. Recent investigations have disclosed various inhibitors of the NLRP3 inflammasome pathway which were validated through in vitro studies and in vivo experiments in animal models of NLRP3-associated disorders. Some of these inhibitors directly target the NLRP3 protein whereas some are aimed at other components and products of the inflammasome. Direct targeting of NLRP3 protein can be a better choice because it can prevent off target immunosuppressive effects, thus restrain tissue destruction. This paper will review the various pharmacological inhibitors of the NLRP3 inflammasome and will also discuss their mechanism of action.

Inflammasome inhibitors: promising therapeutic approaches against cancer

Inflammation has long been accepted as a key component of carcinogenesis. During inflammation, inflammasomes are potent contributors to the activation of inflammatory cytokines that lead to an inflammatory cascade. Considering the contributing role of inflammasomes in cancer progression, inflammasome inhibitors seem to have a promising future in cancer treatment and prevention. Here, we summarize the structures and signaling pathways of inflammasomes and detail some inflammasome inhibitors used to treat various forms of cancer, which we expect to be used in novel anticancer approaches. However, the practical application of inflammasome inhibitors is limited in regard to specific types of cancer, and the associated clinical trials have not yet been completed. Therefore, additional studies are required to explore more innovative and effective medicines for future clinical treatment of cancer.

Glyburide and retinoic acid synergize to promote wound healing by anti-inflammation and RIP140 degradation

Chronic inflammation underlies the development of metabolic diseases and individuals with metabolic disease often also suffer from delayed wound healing due to prolonged inflammation. Resolving inflammation provides a therapeutic strategy in treating metabolic diseases. We previously showed that during an anti-inflammatory response when macrophages were alternatively (M2) polarized, retinoic acid (RA) dramatically activated arginase 1 gene (Arg1), a gene crucial for wound healing. Here we report that a widely used sulfonylurea drug for type 2 diabetes mellitus (T2DM), glyburide, enhances the anti-inflammatory response and synergizes with RA to promote wound healing. Our data also delineate the mechanism underlying glyburide’s anti-inflammatory effect, which is to stimulate the degradation of a pro-inflammatory regulator, Receptor Interacting Protein 140 (RIP140), by activating Ca2+/calmodulin-dependent protein kinase II (CamKII) that triggers specific ubiquitination of RIP140 for degradation. By stimulating RIP140 degradation, glyburide enhances M2 polarization and anti-inflammation. Using a high-fat diet induced obesity mouse model to monitor wound healing effects, we provide a proof-of-concept for a therapeutic strategy that combining glyburide and RA can significantly improve wound healing. Mechanistically, this study uncovers a new mechanism of action of glyburide and a new pathway modulating RIP140 protein degradation that is mediated by CamKII signaling.

Glibenclamide induces apoptosis by activating reactive oxygen species dependent JNK pathway in hepatocellular carcinoma cells

Glibenclamide (Gli) is a widely employed drug in the treatment of type 2 diabetes and many lines of evidence have described its anti-tumor effects in some neoplasms. The aim of the present study was to investigate the effect of Gli on apoptosis of human hepatocellular carcinoma (HCC) cells and to analyze the underlying pathway involved in this action. Two HCC cell lines, HepG-2 and Huh7 were used as the cell models. We found that Gli treatment significantly inhibited cell viability, induced a significant cell-cycle arrest in G₂/M-phase and induced apoptosis in both HepG-2 and Huh7 cells. We further verified that apoptosis induction by Gli was accompanied by increase in ROS levels and activation of the JNK pathway. Scavenging of the intracellular ROS with its blocker N-acetyl-L-cysteine (NAC) could mitigate the Gli-induced apoptosis and JNK activation in the two HCC cell lines. Furthermore, inhibition of JNK pathway by its inhibitor SP100625 effectively reduced Gli-induced apoptosis in HCC cells. In conclusion, Gli treatment significantly induced cell apoptosis by promoting ROS-dependent JNK pathway activation in HCC cells. Gli may be a potential clinical anti-tumor drug for HCC.

The Pathogenic Role of NLRP3 Inflammasome Activation in Inflammatory Bowel Diseases of Both Mice and Humans

BACKGROUND AND AIMS

NLRP3 inflammasome is known to be involved in inflammatory bowel diseases. However, it is controversial whether it is pathogenic or beneficial. This study evaluated the roles of NLRP3 inflammasome in the pathogenesis of inflammatory bowel disease in IL-10-/- mice and humans.

METHODS

NLRP3 inflammasome in colonic mucosa, macrophages, and colonic epithelial cells were analysed by western blotting. The NLRP3 inflammasome components were studied by sucrose density gradient fractionation, chemical cross-linking, and co-immunoprecipitation. The role of NLPR3 inflammasome in the pathogenesis of colitis was extensively evaluated in IL-10-/- mice, using a specific NLPR3 inflammasome inhibitor glyburide.

RESULTS

NLRP3 inflammasome was upregulated in colonic mucosa of both IL-10-/- mice and Crohn's patients. NLRP3 inflammasome activity in IL-10-/- mice was elevated prior to colitis onset; it progressively increased as disease worsened and peaked as macroscopic disease emerged. NLRP3 inflammasome was found in both intestinal epithelial cells and colonic macrophages, as a large complex with a molecular weight of ≥ 360 kDa in size. In the absence of IL-10, NLRP3 inflammasome was spontaneously active and more robustly responsive when activated by LPS and nigericin. Glyburide markedly suppressed NLRP3 inflammasome expression/activation in IL-10-/- mice, leading to not only alleviation of ongoing colitis but also prevention/delay of disease onset. Glyburide also effectively inhibited the release of proinflammatory cytokines/chemokines by mucosal explants from Crohn's patients.

CONCLUSIONS

Abnormal activation of NLRP3 inflammasome plays a major pathogenic role in the development of chronic colitis in IL-10-/- mice and humans. Glyburide, an FDA-approved drug, may have great potential in the management of inflammatory bowel diseases.

Should Side Effects Influence the Selection of Antidiabetic Therapies in Type 2 Diabetes?

PURPOSE OF REVIEW

There are currently over 40 different drugs in 12 distinct classes approved in the USA to treat patients with type 2 diabetes mellitus. This review summarizes our current knowledge about potential side effects of antidiabetic therapy and attempts to apply it to a clinical practice setting.

RECENT FINDINGS

Given the heterogeneity of both the patients and the disease, it is mathematically impossible to test every available drug combination in long-term outcome, prospective, randomized blinded fashion before a clinician decides which agent(s) to prescribe to a specific patient in a given situation. To complicate the clinician's dilemma, there is lack of available tests to predict an individual's response or propensity to side effects. Further, the data available are derived from small, short-term registration trials and typically focus on relative rather than absolute risks of any given drug and do not address the potential adverse outcomes if a patient's diabetes remains untreated. Clinicians have to personalize their choice of antidiabetic therapy based both on the specific characteristics of the patient in front of them (stage of diabetes and its complications, overall health status, socioeconomic situation, other medications present, desire to improve control of diabetes, etc.) and the current knowledge about the relative and absolute balance of benefits and risks of any individual medication in that specific patient. It has to be recognized that this requires constant re-evaluation as database of our experience with antidiabetic therapy expands.

Glibenclamide–sulfonylurea receptor 1 antagonist alleviates LPS-induced BV2 cell activation through the p38/MAPK pathway

We investigated the anti-neuroinflammatory activity and mechanism of glibenclamide, sulfonylurea receptor 1 (Sur1) antagonist, against LPS-induced microglial activationin vitro.

Glibenclamide Attenuates Blood-Brain Barrier Disruption in Adult Mice after Traumatic Brain Injury

Glibenclamide is a hypoglycemic drug that is widely used for the treatment of diabetes mellitus type 2 (DM II), but it also plays a protective role following injury to the central nervous system (CNS). However, the precise mechanisms underlying its neuroprotective actions remain to be elucidated. Therefore, the present study evaluated the effects of glibenclamide on the blood-brain barrier (BBB) in a mouse model of traumatic brain injury (TBI). In the present study, 86 adult male C57BL/6 mice were exposed to a controlled cortical impact (CCI) injury and then received glibenclamide (10 μg) for 3 days. Tight junction (TJ) protein levels, BBB permeability, and tissue hemoglobin levels were evaluated following the CCI injury. Additionally, a biaxial stretch injury was applied to cell cultures of bEnd.3 cells using the Cell Injury Controller II system to explore the mechanisms by which glibenclamide inhibits apoptosis-signaling pathways. Compared with the control group, glibenclamide-treated mice exhibited decreases in brain water content (p < 0.05), tissue hemoglobin levels (p < 0.05), and Evans Blue extravasation (p < 0.01) after the CCI injury. Glibenclamide primarily attenuated apoptosis via the JNK/c-jun signaling pathway and resulted in an elevation of stretch injury-induced ZO-1 expression in bEnd.3 cells (p < 0.01).Glibenclamide downregulated the activity of the JNK/c-jun apoptosis-signaling pathway which, in turn, decreased apoptosis in endothelial cells (ECs). This may have prevented the disruption of the BBB in a mouse model of TBI.

Negative regulation of the inflammasome: keeping inflammation under control

In addition to its roles in controlling infection and tissue repair, inflammation plays a critical role in diverse and distinct chronic diseases, such as cancer, metabolic syndrome, and neurodegenerative disorders, underscoring the harmful effect of an uncontrolled inflammatory response. Regardless of the nature of the stimulus, initiation of the inflammatory response is mediated by assembly of a multimolecular protein complex called the inflammasome, which is responsible for the production of inflammatory cytokines, such as interleukin-1β (IL-1β) and IL-18. The different stimuli and mechanisms that control inflammasome activation are fairly well understood, but the mechanisms underlying the control of undesired inflammasome activation and its inactivation remain largely unknown. Here, we review recent advances in our understanding of the molecular mechanisms that negatively regulate inflammasome activation to prevent unwanted activation in the resting state, as well as those involved in terminating the inflammatory response after a specific insult to maintain homeostasis.

The antidiabetic agent glibenclamide protects airway hyperresponsiveness and inflammation in mice

Glibenclamide has a newly discovered role in inflammation regulation besides its antidiabetic effect. As an inhibitor of ATP-sensitive potassium (KATP) channel, glibenclamide antagonizes the relaxation of the tracheal smooth muscle. This indicates that glibenclamide might attenuate airway inflammation while aggravate airway hyperresponsiveness (AHR) in asthmatics. Clinically, many diabetics with asthma are prescribed with glibenclamide to control blood glucose. However, whether glibenclamide could exert any effects on asthmatic inflammation remains unknown. Using an ovalbumin (OVA)-induced mouse model of asthma, we evaluated the effects of glibenclamide on the AHR and inflammation. Interestingly, glibenclamide reduced all the cardinal features of asthma in OVA-challenged mice, including AHR, airway inflammation, and T-helper type 2 (Th2) cytokines. Glibenclamide also downregulated OVA-induced expressions of vascular cell adhesion molecule 1 (VCAM-1) and phosphorylated signal transducer and activator of transcription 6 (p-STAT6) in the lung. In addition, increased sulfonylurea receptor 1 (SUR1) expression in the lung was observed after the OVA challenge. These findings suggest that the classic sulfonylurea glibenclamide plays an important protective role in the development of asthma, which not only provides the evidence for the safety of prescribed glibenclamide in diabetics combined with asthma but also indicates a possible new therapeutic for asthma via targeting glibenclamide-related pathways.

Inhibiting the Inflammasome: A Chemical Perspective

Inflammasomes are high molecular weight complexes that sense and react to injury and infection. Their activation induces caspase-1 activation and release of interleukin-1β, a pro-inflammatory cytokine involved in both acute and chronic inflammatory responses. There is increasing evidence that inflammasomes, particularly the NLRP3 inflammasome, act as guardians against noninfectious material. Inappropriate activation of the NLRP3 inflammasome contributes to the progression of many noncommunicable diseases such as gout, type II diabetes, and Alzheimer's disease. Inhibiting the inflammasome may significantly reduce damaging inflammation and is therefore regarded as a therapeutic target. Currently approved inhibitors of interleukin-1β are rilonacept, canakinumab, and anakinra. However, these proteins do not possess ideal pharmacokinetic properties and are unlikely to easily cross the blood-brain barrier. Because inflammation can contribute to neurological disorders, this review focuses on the development of small-molecule inhibitors of the NLRP3 inflammasome.

ATP-sensitive potassium channel activation induces angiogenesis in vitro and in vivo

Intense research is conducted to identify new molecular mechanisms of angiogenesis. Previous studies have shown that the angiogenic effects of hydrogen sulfide (H2S) depend on the activation of ATP-sensitive potassium channels (KATP) and that C-type natriuretic peptide (CNP), which can act through KATP, promotes endothelial cell growth. We therefore investigated whether direct KATP activation induces angiogenic responses and whether it is required for the endothelial responses to CNP or vascular endothelial growth factor (VEGF). Chick chorioallantoic membrane (CAM) angiogenesis was similarly enhanced by the direct KATP channel activator 2-nicotinamidoethyl acetate (SG-209) and by CNP or VEGF. The KATP inhibitors glibenclamide and 5-hydroxydecanoate (5-HD) reduced basal and abolished CNP-induced CAM angiogenesis. In vitro, the direct KATP openers nicorandil and SG-209 and the polypeptides VEGF and CNP increased proliferation and migration in bEnd.3 mouse endothelial cells. In addition, VEGF and CNP induced cord-like formation on Matrigel by human umbilical vein endothelial cells (HUVECs). All these in vitro endothelial responses were effectively abrogated by glibenclamide or 5-HD. In HUVECs, a small-interfering RNA-mediated decrease in the expression of the inwardly rectifying potassium channel (Kir) 6.1 subunit impaired cell migration and network morphogenesis in response to either SG-209 or CNP. We conclude that 1) direct pharmacologic activation of KATP induces angiogenic effects in vitro and in vivo, 2) angiogenic responses to CNP and VEGF depend on KATP activation and require the expression of the Kir6.1 KATP subunit, and 3) KATP activation may underpin angiogenesis to a variety of vasoactive stimuli, including H2S, VEGF, and CNP.

Oral antihyperglycemic treatment options for type 2 diabetes mellitus

Table 3 provides an overview of the oral antihyperglycemic drugs reviewed in this article. A 2011 meta-analysis by Bennett and colleagues found low or insufficient quality of evidence favoring an initial choice of metformin, SUs, glinides, TZDs, or (table see text) DPP-4 inhibitors (alpha-glucosidase inhibitors, bromocriptine mesylate, and SGLT2 inhibitors were not included in this meta-analysis) with regard to the outcomes measures of all-cause mortality, cardiovascular events and mortality, and incidence of microvascular disease (retinopathy, nephropathy, and neuropathy) in previously healthy individuals with newly diagnosed T2DM. Likewise, the Bennett and colleagues meta-analysis judged these drugs to be of roughly equal efficacy with regard to reduction of HbA1c (1%–1.6%) from the pretreatment baseline. The ADOPT clinical trial of 3 different and, at the time, popular, oral monotherapies for T2DM provides support for the consensus recommendation of metformin as first-line therapy. The ADOPT trial showed slightly superior HbA1c reduction for rosiglitazone compared with metformin, which was in turn superior to glyburide. However, significant adverse events, including edema, weight gain, and fractures, were more common in the rosiglitazone-treated patients. The implication of this trial is that the combination of low cost, low risk, minimal adverse effects, and efficacy of metformin justifies use of this agent as the cornerstone of oral drug treatment of T2DM. Judicious use of metformin in groups formerly thought to be at high risk for lactic acidosis (ie, those with CHF, chronic kidney disease [eGFR >30 mL/min/1.73 m2], and the elderly) may be associated with mortality benefit rather than increased risk. Secondary and tertiary add-on drug therapy should be individualized based on cost, personal preferences, and overall treatment goals, taking into account the wishes and priorities of the patient.

Glibenclamide attenuates myocardial injury by lipopolysaccharides in streptozotocin-induced diabetic mice

BACKGROUND

Sepsis is a common disease that continues to increase in incidence in the world. Diseases, such as diabetes mellitus, may make the situation worse. Diabetic patients are at increased risk for common infections. This study was designed to investigate the role of glibenclamide on myocardial injury by lipopolysaccharides (LPS) in streptozotocin induced diabetic mice (STZ-mice).

METHODS

LPS was used to induce endotoxemia in STZ-mice. Heart rate and mean arterial pressure were measured by MPA-HBBS. Serum epinephrine level was measured by enzyme-linked immunosorbent assays (ELISA). Myocardial injury was examined by light and transmission electron microscope and TUNEL staining. Macrophage infiltration was measured by immunohistochemistry. Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) levels in myocardial tissue and serum in STZ-mice, and in conditional medium of primary cultured peritoneal macrophages were determined by ELISA. Nalp3 and Caspase-1 protein levels were measured by Western blotting analysis.

RESULTS

STZ administration decreased body weight and increased blood glucose in C57BL/6 mice. LPS injection caused decreases of heart rate and mean arterial pressure, and elevated serum epinephrine level in C57BL/6 mice. Compared with control mice without STZ treatment, LPS induced more severe myocardial injury and macrophage infiltration in STZ-mice, which was attenuated by pretreatment of glibenclamide. LPS stimulation enhanced the levels of IL-1β and TNF-α in both cardiac tissue and serum. Glibenclamide pretreatment significantly inhibited the serum levels of pro-inflammatory cytokines. Either high glucose or LPS increased the levels of IL-1β and TNF-α in the conditional medium of peritoneal macrophages. Glibenclamide treatment suppressed the increase of IL-1β level induced by high glucose and LPS. Furthermore, Nalp3 and Caspase-1 levels were markedly increased by high glucose plus LPS, and both proteins were significantly inhibited by glibenclamide treatment.

CONCLUSIONS

We conclude that glibenclamide could attenuate myocardial injury induced by LPS challenge in STZ-mice, which was possibly related to inhibiting inflammation through Nalp3 inflammasomes.

In vitro biological evaluation of glyburide as potential inhibitor of collagenases

In tissues with upregulated MMP activity, MMP inhibition remains one of the key strategies. Potential inhibitors of MMPs have been tested for almost 30 years, but none have reached clinical utility due to bioavailability issues and adverse effects. This study utilized the approach of drug repurposing for exploring glyburide as a potential inhibitor against collagenases. In silico molecular docking studies were carried out to probe the interactions of glyburide with the active site Zn. Collagenase enzyme activity measurements and zymography analyses using conditioned medium from lung fibroblasts, rheumatoid synovial fibroblasts, and osteoblasts were carried out to confirm the inhibitory activity. Glyburide binds and interacts with the catalytic Zn residues of the collagenases, as evidenced by in silico molecular docking studies. Fluorescence enzyme activity measurements reveal that glyburide inhibits peptide substrate cleavage by all three collagenases in a dose-dependent manner. Collagen zymography studies validated inhibition of these collagenases by glyburide. These results identify glyburide as a potential inhibitor of collagenases and provide an insight into the mechanism of action of this small molecule. Thus, glyburide may offer additional advantages in diabetics, in controlling MMP activation and collagen degradation and could aid in the treatment of diseases with aberrant MMP activity.

Bovine herpesvirus 1 productive infection stimulates inflammasome formation and caspase 1 activity

Bovine herpesvirus 1 (BoHV-1), a significant viral pathogen of cattle, causes inflammation in affected tissue during acute infection. Consequently, we tested whether productively infected bovine cells stimulate inflammasome formation. Expression of two components required for inflammasome formation, the DNA sensor IFI16 (gamma-interferon-inducible protein 16) and NLRP3 (NOD-like receptor family, pyrin domain containing 3), were induced in bovine kidney cells by eight hours after infection. IFI16 was detected in punctate granules localized to the cytoplasm and nucleus. During productive infection, more than ten times more cells were caspase 1 positive, which is activated following inflammasome formation. Two caspase 1 inhibitors had no effect on productive infection. Conversely, another caspase 1 inhibitor, glyburide, significantly inhibited virus infection suggesting it had off-target effects on related enzymes or interfered with infection via non-enzymatic mechanisms. Collectively, these studies demonstrated that BoHV-1 infection stimulated inflammasome formation, which we predict is important for clinical symptoms in cattle.

The once-daily human glucagon-like peptide-1 analog, liraglutide, improves β-cell function in Japanese patients with type 2 diabetes

Aims/Introduction:  β‐cell function was evaluated by homeostasis model assessment of β‐cell function (HOMA‐B) index, proinsulin:insulin and proinsulin:C‐peptide ratios in adult, Japanese type 2 diabetes patients receiving liraglutide.

Materials and Methods:  Data from two randomized, controlled clinical trials (A and B) including 664 Japanese type 2 diabetes patients (mean values: glycated hemoglobin [HbA_1c] 8.61–9.32%; body mass index [BMI] 24.4–25.3 kg/m²) were analyzed. In two 24‐week trials, patients received liraglutide 0.9 mg (n = 268) or glibenclamide 2.5 mg (n = 132; trial A), or liraglutide 0.6, 0.9 mg (n = 176) or placebo (n = 88) added to previous sulfonylurea therapy (trial B).

Results:  Liraglutide was associated with improved glycemic control vs sulfonylurea monotherapy or placebo. In liraglutide‐treated groups in trials A and B, area under the curve (AUC) _{insulin 0–3 h} was improved (P < 0.001 for all) and the AUC_{insulin 0–3 h}:AUC_{glucose 0–3 h} ratio was increased (estimated treatment difference [liraglutide–comparator] 0.058 [0.036, 0.079]). HOMA‐B significantly increased with liraglutide relative to comparator in trial B (P < 0.05), but not in trial A. The reduction in fasting proinsulin:insulin ratio was 50% greater than in comparator groups.

Conclusions:  In Japanese type 2 diabetes patients, liraglutide was associated with effective glycemic control, restoration of prandial insulin response and indications of improved β‐cell function. This trial was registered with Clinicaltrials.gov (trial A: no. NCT00393718/JapicCTI‐060328 and trial B: no. NCT00395746/JapicCTI‐060324). (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00193.x, 2012)

[The use of gliclazide in individualized sulfonylurea therapy]

In addition to the common blood glucose lowering effect, sulfonylurea compounds are different in many aspects from each other. Based on earlier findings the second generation gliclazide has special advantages within this group. Although the number of experimental and clinical observations on gliclazide is continuously increasing, these novel findings are not in the focus anymore due to the appearance of new antidiabetics. This article reviews recent experimental (effect on receptors, the absence of Epac2 activation, antioxidant properties, possible incentive of factors participating in beta-cell differentiation) and pharmacogenomic data, and compares them with clinical observations obtained from gliclazide treatment (hypoglycemias, parameters of cardiovascular outcome). The data underline the advantages of gliclazide, the highly pancreas-selective nature, preservation of the ischemic precondition, favourable hemodynamic properties and potential reduction of the beta-cell loss as compared to other compounds of the group. However, gliclazide is not free from disadvantages characteristic to sulfonylureas in general (blood glucose independent insulin stimulation, beta-cell depletion). Comparing gliclazide with other derivatives of the group, the above data indicate individual benefits for the application when sulfonylurea compound is the drug of choice.

Risk vs benefit in diabetes pharmacotherapy: a rational approach to choosing pharmacotherapy in type 2 diabetes

Type 2 diabetes now affects more than 1 in 10 US adults and is a leading cause of morbidity, mortality, and healthcare expense. There are increasing numbers of available pharmacotherapies, with established agents as well as newer drugs developed from hormones in the incretin pathway, among others. New data are accumulating continuously with respect to potential benefits of both long-standing and new agents, as well as risks identified through post-marketing surveillance. Here we review the commonly prescribed pharmacotherapy options with attention to recently published information and provide a rational approach to choice of therapy.

Combined treatment of glibenclamide and CoCl2 decreases MMP9 expression and inhibits growth in highly metastatic breast cancer

Background

To observe the influence of combination treatment with glibenclamide and CoCl₂ on the growth and invasiveness of TA2 breast cancer, and to detect the protein and mRNA expression of MMP9.

Methods

50 adult female TA2 mice were randomly divided into 5 groups including DMSO control, CoCl_2, glibenclamide, CoCl₂ + glibenclamide and paclitaxel. All of these mice were inoculated with TA2 spontaneous breast cancer cells in the left groin. Nine days after inoculation the tumor could be palpated. Different treatments for each group were then subcutaneously administered near the tumors on the 9th and 14th days after injection. Tumor size was measured to determine the growth curve. All mice were sacrificed on the 18th day after initial inoculation and tumor tissues were collected. Some fresh tissues without necrosis were stored at −80°C for mRNA detection and the other tumor tissue was fixed with 10% formalin for H&E and immunohistochemical staining.

Results

The growth rate of tumor cells in the CoCl₂ + glibenclamide group was lower than that seen in the other groups. On the 14th day, the average volume of tumor in the CoCl₂ + glibenclamide group was the lowest and the difference has statistical significance (P < 0.05), while the differences among the CoCl₂, glibenclamide and paclitaxel had no statistical significance. The mean percentage of cells expressing MMP9 and PCNA was the lowest in the CoCl₂ + glibenclamide group (P < 0.05). MMP9 mRNA expression paralleled MMP9 protein expression in these groups (P < 0.05).

Conclusions

Combined treatment with glibenclamide and CoCl₂ inhibits TA2 spontaneous breast cancer growth and invasiveness with effects similar to paclitaxel.

Anti-nociceptive and anti-edematogenic effects of glibenclamide in a model of acute gouty attack in rats

OBJECTIVE AND DESIGN

We investigated the effect of glibenclamide on inflammatory parameters in a model of acute gouty attack in rats.

TREATMENT

Intra-articular injection of 50 μl of monosodium urate (MSU) crystals (1.25 mg/site) was used to induce gout-related inflammation. The effects of glibenclamide (1-10 mg/kg, s.c.) or dexamethasone (8 mg/kg, s.c., positive control) were assessed on several inflammation parameters.

METHODS

Spontaneous nociception assessment, edema measurement, total and differential leucocyte counts, interleukin (IL)-1β release, prostaglandin E2 production and determination of blood glucose levels were analyzed. Peritoneal macrophages were incubated with MSU and levels of IL-1β were measured. Statistical significance was assessed by one- or two-way analysis of variance.

RESULTS

Glibenclamide (3 mg/kg) or dexamethasone (8 mg/kg) prevented nociception and edema induced by MSU injection in rats. Glibenclamide did not affect leukocyte infiltration, IL-1β release and PGE2 production, but only reduced IL-1β production by MSU-stimulated macrophages at very high concentration (200 μM). Dexamethasone significantly reduced leukocyte infiltration, IL-1β release and PGE2 production. Glibenclamide reduced whereas dexamethasone increased blood glucose levels of MSU-injected rats.

CONCLUSIONS

Glibenclamide reduced nociception and edema, but not leukocyte infiltration, IL-1β release and PGE2 production. However, its substantial effect on nociception and edema suggests that glibenclamide can be an interesting option as an adjuvant treatment for pain induced by acute attacks of gout.

Adverse cardiovascular events during treatment with glyburide (glibenclamide) or gliclazide in a high-risk population

AIMS

Sulphonylureas promote insulin release by inhibiting pancreatic potassium channels. Older sulphonylureas such as glyburide (glibenclamide), but not newer ones such as gliclazide, antagonize similar channels in myocardium, interfering with the protective effects of ischaemic preconditioning. Whether this imparts a higher risk of adverse cardiac events is unknown.

METHODS

We conducted a population-based cohort study of patients aged 66 years and older who were hospitalized for acute myocardial infarction or who underwent percutaneous coronary intervention between 1 April 2007 and 31 March 2010 while receiving either glyburide or gliclazide. We used a high-dimensional propensity score matching process to ensure similarity of glyburide- and gliclazide-treated patients. The primary outcome was a composite of death or hospitalization for myocardial infarction or heart failure.

RESULTS

During the 2-year study period, we matched 1690 patients treated with glyburide to 984 patients treated with gliclazide at the time of hospitalization for acute myocardial infarction or percutaneous coronary intervention. We found no difference in the risk of the composite outcome among patients receiving glyburide (adjusted hazard ratio 1.01; 95% CI 0.86-1.18). We found similar results in secondary analyses of each outcome individually, and in two supplementary analyses (haemorrhage and pneumonia) in which we anticipated no difference between the two patient groups.

CONCLUSIONS

Among older patients hospitalized for acute myocardial infarction or percutaneous coronary intervention, treatment with glyburide is not associated with an increased risk of future adverse cardiovascular events relative to gliclazide, suggesting that the effect of glyburide on ischaemic preconditioning is of little clinical relevance.

Second line therapy: type 2 diabetic subjects failing on metformin GLP-1/DPP-IV inhibitors versus sulphonylurea/insulin: for GLP-1/DPP-IV inhibitors

Following diagnosis, type 2 diabetic subjects are invariably treated with life style modifications and metformin. However, majority of these subjects require addition of another therapeutic agent singly or in combination; with or without insulin within few months to few years. For several decades, sulphonylureas and insulin have been the second line agent of choice. Clinical practice guidelines also suggest a similar approach. Subsequently thiazolidinediones, alpha glucose inhibitors and other agents were added to therapeutic armamentarium. Unfortunately, none of these treatment options could address the issue of progressive decline in beta cell function. Furthermore, they are responsible for unacceptable incidence of hypoglycaemia, weight gain and other side effects related to individual agents. Type 2 diabetic subjects have great propensity to develop cardiovascular complications. Sulphonylureas, insulin and thiazolidinediones have all been associated with adverse cardiovascular outcomes in differing magnitude. It has been made mandatory by regulatory agencies to ensure cardiovascular safety of any new anti-diabetic agent. Glucagon Like Peptide-1(GLP-1)-based therapies have been able to address several of these issues. Incretin mimetics and Di Peptidyl Dipeptidase IV (DPP-IV) inhibitors cause glucose-dependent insulin secretion and glucagon suppression from beta and alpha cells of the pancreas respectively. They owe this property to their binding with G-Protein-coupled receptors leading to an increased amount of c-AMP. They do not cause beta cell exhaustion. On the contrary such agents prevent beta cell apoptosis. Clinical trials have established the superiority of incretin mimetics particularly liraglutide against comparators including glimepiride, rosiglitazone and insulin Glargine in terms of efficacy. Furthermore, they have shown evidence towards beta cell protection, significant weight loss, minimal hypoglycaemia and favourable impact on surrogate markers of cardiovascular outcomes. DPP-IV inhibitors have limited ability to achieve glycaemic targets. However, they are weight neutral, cause minimal hypoglycaemia and have some beneficial effect on beta cell function. Finally, they are very well tolerated.

Thiazolidinediones and cardiovascular risk - a question of balance

BACKGROUND

Several recent meta-analyses of adverse event data from randomized controlled trials with rosiglitazone reveal a possible association between this thiazolidinedione and an increased risk of ischemic myocardial events. This has led to debate on the overall clinical benefit of glitazone therapy for type 2 diabetes. Pioglitazone, on the other hand, has the most extensive cardiovascular outcomes database of all current glucose-lowering therapies, including a large prospective randomized controlled trial designed specifically to assess cardiovascular outcomes (PROactive). The available data suggest that pioglitazone is associated with a reduction in macrovascular risk.

AIMS

In this review, we highlight some of the key factors that need to be considered when assessing the net clinical benefit of thiazolidinediones, focussing on both class effects and those specific to either rosiglitazone or pioglitazone.

RESULTS

For pioglitazone there appears to be no increase in the risk of overall macrovascular events and no adverse clinical consequences of developing signs of heart failure. Furthermore, there is good evidence of significant benefit regarding the composite of death, MI or stroke.

CONCLUSION

The benefits seen with pioglitazone appear to outweigh the risks.

Glyburide is anti-inflammatory and associated with reduced mortality in melioidosis

Patients with diabetes have better survival from septic melioidosis than patients who without diabetes. This difference was seen only in patients taking glyburide prior to presentation and was associated with an anti-inflammatory effect of glyburide.

Background. Patients with diabetes mellitus are more prone to bacterial sepsis, but there are conflicting data on whether outcomes are worse in diabetics after presentation with sepsis. Glyburide is an oral hypoglycemic agent used to treat diabetes mellitus. This K_ATP-channel blocker and broad-spectrum ATP-binding cassette (ABC) transporter inhibitor has broad-ranging effects on the immune system, including inhibition of inflammasome assembly and would be predicted to influence the host response to infection.

Methods. We studied a cohort of 1160 patients with gram-negative sepsis caused by a single pathogen (Burkholderia pseudomallei), 410 (35%) of whom were known to have diabetes. We subsequently studied prospectively diabetics with B. pseudomallei infection (n = 20) to compare the gene expression profile of peripheral whole blood leukocytes in patients who were taking glyburide against those not taking any sulfonylurea.

Results. Survival was greater in diabetics than in nondiabetics (38% vs 45%, respectively, P = .04), but the survival benefit was confined to the patient group taking glyburide (adjusted odds ratio .47, 95% confidence interval .28–.74, P = .005). We identified differential expression of 63 immune-related genes (P = .001) in patients taking glyburide, the sum effect of which we predict to be antiinflammatory in the glyburide group.

Conclusions. We present observational evidence for a glyburide-associated benefit during human melioidosis and correlate this with an anti-inflammatory effect of glyburide on the immune system.

Impact of type of preadmission sulfonylureas on mortality and cardiovascular outcomes in diabetic patients with acute myocardial infarction

BACKGROUND

The impact of antidiabetic medications on clinical outcomes in patients developing acute myocardial infarction (MI) is controversial. We sought to determine whether in-hospital outcomes in patients who were on sulfonylureas (SUs) when they developed their MIs differed from that of diabetic patients not receiving SUs and whether clinical outcomes were related to the pancreatic cells specificity of SUs.

METHODS AND RESULTS

We analyzed the outcomes of the 1310 diabetic patients included in the nationwide French Registry of Acute ST-Elevation and Non-ST-Elevation Myocardial Infarction in 2005. Medications used before the acute episode were recorded. In-hospital complications were analyzed according to prior antidiabetic treatment. Mortality was lower in patients previously treated with SUs (3.9%) vs. those on other oral medications (6.4%), insulin (9.4%), or no medication (8.4%) (P = 0.014). Among SU-treated patients, in-hospital mortality was lower in patients receiving pancreatic cells-specific SUs (gliclazide or glimepiride) (2.7%), compared with glibenclamide (7.5%) (P = 0.019). Arrhythmias and ischemic complications were also less frequent in patients receiving gliclazide/glimepiride. The lower risk in patients receiving gliclazide/glimepiride vs. glibenclamide persisted after multivariate adjustment (odds ratio 0.15; 95% confidence interval 0.04-0.56) and in propensity score-matched cohorts.

CONCLUSION

In this nationwide registry of patients hospitalized for acute MI, no hazard was associated with the use of SUs before the acute episode. In addition, patients previously receiving gliclazide/glimepiride had improved in-hospital outcomes, compared with those on glibenclamide.

Effects of oral glucose-lowering drugs on long term outcomes in patients with diabetes mellitus following myocardial infarction not treated with emergent percutaneous coronary intervention--a retrospective nationwide cohort study

Background

The optimum oral pharmacological treatment of diabetes mellitus to reduce cardiovascular disease and mortality following myocardial infarction has not been established. We therefore set out to investigate the association between individual oral glucose-lowering drugs and cardiovascular outcomes following myocardial infarction in patients with diabetes mellitus not treated with emergent percutaneous coronary intervention.

Materials and methods

All patients aged 30 years or older receiving glucose-lowering drugs (GLDs) and admitted with myocardial infarction (MI) not treated with emergent percutaneous coronary intervention in Denmark during 1997-2006 were identified by individual-level linkage of nationwide registries of hospitalizations and drug dispensing from pharmacies. Multivariable Cox regression models adjusted for age, sex, calendar year, comorbidity, and concomitant pharmacotherapy were used to assess differences in the composite endpoint of non-fatal MI and cardiovascular mortality between individual GLDs, using metformin monotherapy as reference.

Results

The study comprised 9876 users of GLDs admitted with MI. The mean age was 72.3 years and 56.5% of patients were men. A total of 3649 received sulfonylureas and 711 received metformin at admission. The average length of follow-up was 2.2 (SD 2.6) years. A total of 6,171 patients experienced the composite study endpoint. The sulfonylureas glibenclamide, glimepiride, glipizide, and tolbutamide were associated with increased risk of cardiovascular mortality and/or nonfatal MI with hazard ratios [HRs] of 1.31 (95% confidence interval [CI] 1.17-1.46), 1.19 (1.06-1.32), 1.25 (1.11-1.42), and 1.18 (1.03-1.34), respectively, compared with metformin. Gliclazide was the only sulfonylurea not associated with increased risk compared with metformin (HR 1.03 [0.88-1.22]).

Conclusions

In patients with diabetes mellitus admitted with MI not treated with emergent percutaneous coronary intervention, monotherapy treatment with the sulfonylureas glibenclamide, glimepiride, glipizide, and tolbutamide was associated with increased cardiovascular risk compared with metformin monotherapy.

Glyburide inhibits the Cryopyrin/Nalp3 inflammasome

Glyburide, a sulfonylurea drug commonly used to treat type 2 diabetes, shuts down IL-1β secretion by preventing Cyropyrin activation.

Inflammasomes activate caspase-1 for processing and secretion of the cytokines interleukin-1β (IL-1β) and IL-18. Cryopyrin/NALP3/NLRP3 is an essential component of inflammasomes triggered by microbial ligands, danger-associated molecular patterns (DAMPs), and crystals. Inappropriate Cryopyrin activity has been incriminated in the pathogenesis of gouty arthritis, Alzheimer's, and silicosis. Therefore, inhibitors of the Nalp3 inflammasome offer considerable therapeutic promise. In this study, we show that the type 2 diabetes drug glyburide prevented activation of the Cryopyrin inflammasome. Glyburide's cyclohexylurea group, which binds to adenosine triphosphatase (ATP)–sensitive K⁺ (K_ATP) channels for insulin secretion, is dispensable for inflammasome inhibition. Macrophages lacking K_ATP subunits or ATP-binding cassette transporters also activate the Cryopyrin inflammasome normally. Glyburide analogues inhibit ATP- but not hypothermia-induced IL-1β secretion from human monocytes expressing familial cold-associated autoinflammatory syndrome–associated Cryopyrin mutations, thus suggesting that inhibition occurs upstream of Cryopyrin. Concurrent with the role of Cryopyrin in endotoxemia, glyburide significantly delays lipopolysaccharide-induced lethality in mice. Therefore, glyburide is the first identified compound to prevent Cryopyrin activation and microbial ligand-, DAMP-, and crystal-induced IL-1β secretion.

Protective effect of Lycium barbarum polysaccharide 4 on kidneys in streptozotocin-induced diabetic rats

Lycium barbarum polysaccharide (LBP) has been shown to have hypoglycemic and antioxidative properties, although its mode of action is yet unknown. Because oxidative stress is implicated in the pathogenesis of diabetic nephropathy, we evaluated the protective effect of LBP-4, the major active component of Lycium barbarum, on the defensive antioxidative mechanism in kidneys in a streptozotocin-induced diabetic rat model. Moreover, we investigated the effects of LBP-4 on the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in isolated mesangial cells. The role of protein kinase C (PKC)-dependent and -independent pathways in LBP-4-reduced ERK1/2 was studied by bisindolylmaleimide (BIM) IV, an inhibitor of PKC. Diabetic rats treated with LBP-4 (10 mg/kg) for 8 weeks showed increased activity of antioxidant enzymes and increased scavenging of oxygen radicals, while the activity of PKC in the renal cortex was maintained at a physiological level. The decreased activation of ERK1/2 in mesangial cells, through the involvement of PKC, could explain the protective mechanism in kidneys of diabetic rats treated with LBP-4.

GLP-1 agonist-based therapies: an emerging new class of antidiabetic drug with potential cardioprotective effects

Cardiovascular disease is a leading cause of death in the United States and across the world, and better therapies are constantly being sought to improve patient outcomes. Recent studies have brought our attention to the mechanisms of glucagon-like peptide 1 (GLP-1). Not only does it demonstrate beneficial effects in regard to cardiovascular risk factors (i.e., diabetes, lipid management, and weight control), but it also has been shown in animal studies to have positive cardiac effects irrespective of its effects on glucose control and weight loss. This review discusses the biology of GLP-1 and its effects on cardiovascular risk factors, and it also elaborates on the positive direct cardiovascular outcomes of GLP-1 in animal studies.

Is the combination of sulfonylureas and metformin associated with an increased risk of cardiovascular disease or all-cause mortality?: a meta-analysis of observational studies

OBJECTIVE

Observational studies assessing the association of combination therapy of metformin and sulfonylurea on all-cause and/or cardiovascular mortality in type 2 diabetes have shown conflicting results. We therefore evaluated the effects of combination therapy of sulfonylureas and metformin on the risk of all-cause mortality and cardiovascular disease (CVD) among people with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A MEDLINE search (January 1966-July 2007) was conducted to identify observational studies that examined the association between combination therapy of sulfonylureas and metformin on risk of CVD or all-cause mortality. From 299 relevant reports, 9 were included in the meta-analysis. In these studies, combination therapy of metformin and sulfonylurea was assessed, the risk of CVD and/or mortality was reported, and adjusted relative risk (RR) or equivalent (hazard ratio and odds ratio) and corresponding variance or equivalent was reported.

RESULTS

The pooled RRs (95% CIs) of outcomes for individuals with type 2 diabetes prescribed combination therapy of sulfonylureas and metformin were 1.19 (0.88-1.62) for all-cause mortality, 1.29 (0.73-2.27) for CVD mortality, and 1.43 (1.10-1.85) for a composite end point of CVD hospitalizations or mortality (fatal or nonfatal events).

CONCLUSIONS

The combination therapy of metformin and sulfonylurea significantly increased the RR of the composite end point of cardiovascular hospitalization or mortality (fatal and nonfatal events) irrespective of the reference group (diet therapy, metformin monotherapy, or sulfonylurea monotherapy); however, there were no significant effects of this combination therapy on either CVD mortality or all-cause mortality alone.