Pioglitazone has anti-inflammatory effects in patients with Type 2 diabetes

Overview of oxidative stress and inflammation in diabetes

The global prevalence of diabetes has increased significantly, leading to various complications and a negative impact on quality of life. Hyperglycemia hyperglycemic-induced oxidative stress (OS) and inflammation are closely associated with the development and progression of type 2 diabetes mellitus (T2D) and its complications. This review explores the effect of T2D on target organ damage and potential treatments to minimize this damage. The paper examines the pathophysiology of T2D, focusing on low-grade chronic inflammation and OS and on their impact on insulin resistance. The review discusses the role of inflammation and OS in the development of microvascular and macrovascular complications. The findings highlight the mechanisms by which inflammatory cytokines, stress kinases, and reactive oxygen species (ROS) interfere with insulin signaling pathways, leading to impaired glucose metabolism and organ dysfunction. Lifestyle interventions, including a balanced diet and exercise, can help reduce chronic inflammation and OS, thereby preventing and controlling T2D and its associated complications. Additionally, various antioxidants and anti-inflammatory agents show potential in reducing OS and inflammation. Some anti-diabetic drugs, like pioglitazone, metformin, and glucagon-like peptide-1 (GLP-1) agonists, may also have anti-inflammatory effects. Further research, including randomized controlled trials, is needed to evaluate the efficacy of these interventions.

Crosstalk between Oxidative Stress and Inflammation Induced by Ionizing Radiation in Healthy and Cancerous Cells

Radiotherapy (RT) is a unique modality in cancer treatment with no replacement in many cases and uses a tumoricidal dose of various ionizing radiation (IR) types to kill cancer cells. It causes oxidative stress through reactive oxygen species (ROS) production or the destruction of antioxidant systems. On the other hand, RT stimulates the immune system both directly and indirectly by releasing danger signals from stress-exposed and dying cells. Oxidative stress and inflammation are two reciprocal and closely related mechanisms, one induced and involved by the other. ROS regulates the intracellular signal transduction pathways, which participate in the activation and expression of pro-inflammatory genes. Reciprocally, inflammatory cells release ROS and immune system mediators during the inflammation process, which drive the induction of oxidative stress. Oxidative stress or inflammation-induced damages can result in cell death (CD) or survival mechanisms that may be destructive for normal cells or beneficial for cancerous cells. The present study has focused on the radioprotection of those agents with binary effects of antioxidant and anti-inflammatory mechanisms IR-induced CD.

Adding SGLT2 Cotransporter Inhibitor to PPARγ Activator Does Not Provide an Additive Effect in the Management of Diabetes-Induced Vascular Dysfunction

INTRODUCTION

Endothelial dysfunction (ED) plays a key role in the pathogenesis of diabetic vascular complications. In monotherapy, dapagliflozin (Dapa) as well as pioglitazone (Pio) prevent the progression of target organ damage in both type 1 (T1DM) and type 2 diabetes. We investigated whether the simultaneous PPAR-γ activation and SGLT2 cotransporter inhibition significantly alleviate ED-related pathological processes and thus normalize vascular response in experimental T1DM.

METHODS

Experimental diabetes was induced by streptozotocin (STZ; 55 mg/kg, i.p.) in Wistar rats. Dapa (10 mg/kg), Pio (12 mg/kg), or their combination were administrated to the STZ rats orally. Six weeks after STZ administration, the aorta was excised for functional studies and real-time qPCR analysis.

RESULTS

In the aorta of diabetic rats, impaired endothelium-dependent and independent relaxation were accompanied by the imbalance between vasoactive factors (eNos, Et1) and overexpression of inflammation (Tnfα, Il1b, Il6, Icam, Vcam) and oxidative stress (Cybb) markers. Pio monotherapy normalized response to vasoactive substances and restored balance between Et1-eNos expression, while Dapa treatment was ineffective. Nevertheless, Dapa and Pio monotherapy significantly reverted inflammation and oxidative stress markers to normal values. The combination treatment exhibited an additive effect in modulating Il6 expression, reaching the effect of Pio monotherapy in other measured parameters.

CONCLUSION

Particularly, Pio exerts a vasoprotective character when used in monotherapy. When combined with Dapa, it does not exhibit an expected additive effect within modulating vasoreactivity or oxidative stress, though having a significant influence on IL6 downregulation.

Lipid-induced alteration in retinoic acid signaling leads to mitochondrial dysfunction in HepG2 and Huh7 cells

A surfeit of mitochondrial reactive oxygen species (ROS) and inflammation serve as obligatory mediators of lipid-associated hepatocellular maladies. While retinoid homeostasis is essential in restoring systemic energy balance, its role in hepatic mitochondrial function remains elusive. The role of lecithin-retinol acyltransferase (LRAT) in maintenance of retinoid homeostasis is appreciated earlier; however, its role in modulating retinoic acid (RA) bioavailability upon lipid-imposition is unexplored. We identified LRAT overexpression in high-fat diet (HFD)-fed rats and palmitate-treated hepatoma cells. Elevation in LRAT expression depletes RA production and deregulates RA signaling. This altered RA metabolism enhances fat accumulation, accompanied by inflammation that leads to impaired mitochondrial function through enhanced ROS generation. Hence, LRAT inhibition could be a novel approach preventing lipid-induced mitochondrial dysfunction in hepatoma cells.

Added to pre-existing inflammation, mRNA-lipid nanoparticles induce inflammation exacerbation (IE)

Current nucleoside-modified RNA lipid nanoparticle (modmRNA-LNP) technology has successfully paved the way for the highest clinical efficacy data from next-generation vaccinations against SARS-CoV-2 during the COVID-19 pandemic. However, such modmRNA-LNP technology has not been characterized in common pre-existing inflammatory or immune-challenged conditions, raising the risk of adverse clinical effects when administering modmRNA-LNPs in such cases. Herein, we induce an acute-inflammation model in mice with lipopolysaccharide (LPS) intratracheally (IT), 1 mg kg-1, or intravenously (IV), 2 mg kg-1, and then IV administer modmRNA-LNP, 0.32 mg kg-1, after 4 h, and screen for inflammatory markers, such as pro-inflammatory cytokines. ModmRNA-LNP at this dose caused no significant elevation of cytokine levels in naive mice. In contrast, shortly after LPS immune stimulation, modmRNA-LNP enhanced inflammatory cytokine responses, Interleukin-6 (IL-6) in serum and Macrophage Inflammatory Protein 2 (MIP-2) in liver significantly. Our report identifies this phenomenon as inflammation exacerbation (IE), which was proven to be specific to the LNP, acting independent of mRNA cargo, and was demonstrated to be time- and dose-dependent. Macrophage depletion as well as TLR3 -/- and TLR4-/- knockout mouse studies revealed macrophages were the immune cells involved or responsible for IE. Finally, we show that pretreatment with anti-inflammatory drugs, such as corticosteroids, can partially alleviate IE response in mice. Our findings characterize the importance of LNP-mediated IE phenomena in gram negative bacterial inflammation, however, the generalizability of modmRNA-LNP in other forms of chronic or acute inflammatory and immune contexts needs to be addressed.

Elevated circulating CD16+ monocytes and TLR4+ monocytes in older adults with multiple cardiometabolic disease risk factors

We endeavored to examine relationships between circulating monocyte phenotype and cardio-metabolic disease risk, in healthy, older adults. We performed a secondary data analysis on men and women, 55-75 yr, who were assigned to groups based on cardio-metabolic risk factors other than age. Subject in the low risk group (n = 16, 12 females) had fewer than three risk factors. Subjects in the elevated risk group (n = 29, 19 females) had three or more risk factors. Along with baseline screening for fitness and body composition, resting blood samples were assessed for markers of inflammation including: monocyte phenotype (inflammatory monocytes), monocyte cell-surface TLR4 expression, and serum C-reactive protein. The low risk group had a smaller (19.3% difference; p < 0.0001) waist circumference and lower body fat weight (36.3%; p < 0.0001), but higher V̇0₂max (45.5%; p = 0.0019). There were no mean differences (p > 0.05) between the low and elevated risk groups for BMI, serum cholesterol, fasting glucose, or leg press 1RM. The low risk group had lower CRP (114.7%, p = 0.0002), higher CD14⁺CD16^- (classical) monocytes (6.7%; p = 0.0231) and fewer CD14⁺CD16⁺ (inflammatory) monocytes (46.2%; p = 0.0243) than the elevated risk group. The low risk group also had a lower percentage of CD14⁺CD16^- monocytes that were positive for TLR4 (14.0%; p = 0.0328). Older men and women with fewer cardio-metabolic risk factors had lower serum and cellular markers of inflammation and higher aerobic capacity.

Pioglitazone mediates apoptosis in Caki cells via downregulating c-FLIP(L) expression and reducing Bcl-2 protein stability

Pioglitazone is an anti-diabetic agent used in the treatment of type 2 diabetes, which belongs to the thiazolidinediones (TZDs) group. TZDs target peroxisome proliferator-activated receptor γ (PPARγ), which functions as a transcription factor of the nuclear hormone receptor. Pioglitazone has antitumor effects in several cancer types and could be a tool for drug therapy in various cancer treatments. Nevertheless, the molecular basis for pioglitazone-induced anticancer effects in renal cancer (RC) has not yet been elucidated. Thus, the aim of the present study was to investigate the detailed signaling pathway underlying pioglitazone-induced apoptosis in Caki cells derived from human clear cell renal cell carcinoma. As a result, it was demonstrated by flow cytometry analysis and Annexin V-propidium iodide staining that pioglitazone treatment induced apoptotic cell death in a dose-dependent manner in Caki cells. The protein expression levels of cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein (c-FLIP)_(L) and Bcl-2, which were determined by western blotting, decreased after pioglitazone treatment in Caki cells. Flow cytometry and western blot analyses demonstrated that pioglitazone-mediated apoptosis was blocked following pretreatment with the pan-caspase inhibitor, z-VAD-fmk, indicating that pioglitazone-induced apoptosis was mediated via a caspase-dependent signaling pathway. However, the reactive oxygen species (ROS) scavenger, N-acetylcysteine (NAC), did not affect pioglitazone-mediated apoptosis and degradation of c-FLIP_(L) and Bcl-2 protein. Of note, it was found by western blot analysis that Bcl-2 protein expression was downregulated by the decreased protein stability of Bcl-2 in pioglitazone-treated Caki cells. In conclusion, these findings indicated that pioglitazone-induced apoptosis is regulated through caspase-mediated degradation of FLIP_(L) and reduction of Bcl-2 protein stability, suggesting that pioglitazone is a feasible apoptotic agent that could be used in the treatment of human RC.

The impact of maternal obesity on inflammatory processes and consequences for later offspring health outcomes

Obesity is a global epidemic, affecting both developed and developing countries. The related metabolic consequences that arise from being overweight or obese are a paramount global health concern, and represent a significant burden on healthcare systems. Furthermore, being overweight or obese during pregnancy increases the risk of offspring developing obesity and other related metabolic complications in later life, which can therefore perpetuate a transgenerational cycle of obesity. Obesity is associated with a chronic state of low-grade metabolic inflammation. However, the role of maternal obesity-mediated alterations in inflammatory processes as a mechanism underpinning developmental programming in offspring is less understood. Further, the use of anti-inflammatory agents as an intervention strategy to ameliorate or reverse the impact of adverse developmental programming in the setting of maternal obesity has not been well studied. This review will discuss the impact of maternal obesity on key inflammatory pathways, impact on pregnancy and offspring outcomes, potential mechanisms and avenues for intervention.

Effects of medication-treated diabetes on incidence and progression of knee osteoarthritis: a longitudinal analysis of the Osteoarthritis Initiative data

Diabetes has been proposed as a factor involved in the pathogenesis of osteoarthritis (OA). Currently, there is a lack of research evaluating the prospective impact of diabetes on OA structural outcomes. In this study, we assessed the effects of medication-treated diabetes on incidence and progression of knee OA. We analysed longitudinal data from the multi-center, longitudinal, prospective observational Osteoarthritis Initiative (OAI) study. The main outcomes were radiographic OA incidence (development of Kellgren-Lawrence grade 2 with joint space narrowing, JSN) and progression (increase in semiquantitative JSN or a new knee replacement). For the study of incidence, we selected participants with KL <2 or /KL = 2 without JSN at baseline (incidence sample). To evaluate progression, we selected participants with baseline JSN <3 (progression sample). We used generalized estimating equations (GEE) logistic regression with adjustment for potential confounders to evaluate the effects of medication-treated diabetes on knee OA incidence and progression. We studied 3725 knees (3498 non-diabetic and 228 diabetic) in the incidence sample and 3594 knees (3335 non-diabetic and 259 diabetic) in the progression sample. Medication-treated diabetes did not have an effect on knee OA incidence (odds ratio, OR 0.53, 95% confidence interval, CI 0.23-1.5). There was an independent association between medication-treated diabetes and reduced progression of knee OA [OR 0.66, 95% CI (0.44-0.98)]. Medication-treated diabetes has no effect on knee OA incidence but reduces knee OA progression. The role of diabetes and anti-diabetic drugs in knee OA progression needs further exploration.

Differential behaviour of epicardial adipose tissue-secretomes with high and low orosomucoid levels from patients with cardiovascular disease in H9C2 cells

Epicardial adipose tissue releases orosomucoid (ORM), an acute phase protein with multiple modulatory and protective properties. We aimed to identify the effect of EAT-supernatants according to their ORM levels on H9C2 cells. H9C2 were cultured with EAT-secretomes or ORM protein itself on a Real-Time Cell Analyser. Secretome proteins identification was performed by LC-mass spectrometry according to their ORM levels. Two of them were validated by ELISA in EAT-supernatants from 42 patients. ORM effect on H9C2 and neonatal rat cardiomyocytes apoptosis under hypoxia with or without fatty acid treatment was determined by Annexin-V flow cytometry measurement. Caspase-3 expression levels were determined by western blot in H9C2. Our results showed a differential effect of EAT-secretomes according their ORM levels. Although additional secreted proteins can contribute to their beneficial effects, ORM reduced hypoxia-induced apoptosis through caspase-3 inhibition. Our data showed the cardioprotective role of ORM and suggest that its quantification on EAT secretomes might help us to find new secreted factors with a cardioprotective role.

Increased orosomucoid in urine is an independent predictor of cardiovascular and all-cause mortality in patients with type 2 diabetes at 10 years of follow-up

AIMS

To evaluate whether increased urinary orosomucoid excretion rate (UOER) is an independent predictor of cardiovascular and all-cause mortality in type 2 diabetes (T2DM) and type 1 diabetes (T1DM) at 10years of follow-up.

METHOD

We followed 430 patients with T2DM and 148 patients with T1DM until emigration, death or November 2011. We measured UOER levels in overnight urine samples.

RESULTS

Descriptive data are given in the article. In patients with T2DM and T1DM, all-cause mortality (log-rank test, p<0.01 for both types) and cardiovascular mortality (log-rank test, p<0.01 for T2DM and p=0.04 for T1DM) were significantly higher in patients with increased UOER. Normoalbuminuric patients with T2DM and increased UOER levels had higher all-cause and cardiovascular mortality (log-rank test, p<0.01 for both types). UOER was independently predictive of all-cause (HR 1.52; 95% CI 1.10-2.09; p=0.01) and cardiovascular (HR 2.31; 95% CI 1.46-3.66; p<0.01) mortality in patients with T2DM, but not in patients with T1DM.

CONCLUSION

UOER is an independent predictor of all-cause and cardiovascular mortality even in normoalbuminuric patients with T2DM at 10years of follow-up. Further studies are needed in order to evaluate the prognostic and clinical relevance.

Pioglitazone improves the cardiovascular profile in patients with uncomplicated systemic lupus erythematosus: a double-blind randomized clinical trial

OBJECTIVE

We studied the effect of pioglitazone on insulin levels, inflammation markers, high-density lipoprotein (HDL) composition and subclasses distribution, in young women with uncomplicated systemic lupus erythematosus (SLE).

METHODS

This double-blind trial included 30 premenopausal women (30 ±8 years old) with SLE, who were randomized to pioglitazone (30 mg/day) or placebo treatment for 3 months. Plasma and HDL lipids were determined by colorimetric enzymatic assays, insulin by radioimmunometric assay, inflammation by immunonephelometry and HDL size and subclasses distribution by a native 4-30% polyacrylamide gradient gel electrophoresis.

RESULTS

Compared with placebo, pioglitazone significantly increased HDL-cholesterol plasma levels (14.2%), reduced fasting insulin plasma levels (23.6%) and the homeostasis model assessment-insulin resistance (31.7%). C-reactive protein (70.9%) and serum amyloid A (34.9%) were also significantly reduced with the pioglitazone use, whereas the HDL particle size was increased (8.80 nm vs. 8.95 nm; p = 0.044) by changes in the distribution of HDL(2b), HDL(3b), and HDL(3c) subclasses. The change in HDL size correlated with a rise in free and cholesterol-ester content in the HDL particles.

CONCLUSION

Pioglitazone significantly enhanced insulin sensitivity, reduced inflammation, and modified HDL characteristics, suggesting a potential beneficial effect of this drug in patients with SLE with a risk to develop cardiovascular disease.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov Protocol Registration System, with the number NCT01322308.

Combined pioglitazone and metformin treatment maintains the beneficial effect of short-term insulin infusion in patients with type 2 diabetes: results from a pilot study

BACKGROUND

The aim of our study was to examine the efficacy of short-term intravenous insulin intervention followed by oral pioglitazone/metformin therapy to prevent patients from continuous insulin application.

METHODS

This prospective, open-label, 4-month pilot study comprised of 14 diabetes patients (5 female, 9 male; age 60 +/- 2 years; body mass index 29 +/- 3.2 kg/m(2); hemoglobin A1c [HbA1c] 7.6 +/- 1.1%) with (1) insufficient glycemic control under a dose of metformin >or=1700 mg/day and/or metformin plus additional oral antidiabetes drugs (OADs) and (2) appropriate residual beta-cell function. Initially, an inpatient 34 h continuous intravenous insulin infusion was performed, and metformin was given (2x 850 mg/day). Insulin was stopped, and pioglitazone 30 mg/day was added at the second inpatient day. Patients were followed for four months. Efficacy parameters [change of HbA1c, fasting blood glucose [FBG], intact proinsulin, adiponectin, and high-sensitivity C-reactive protein (hsCRP)] were assessed after initial normalization of blood glucose values by intravenous insulin and at the study end point.

RESULTS

During the acute insulin intervention, FBG levels were stabilized in all study subjects. In the following OAD treatment period, five patients showed an improvement of HbA1c > 0.5% [35.7%; seven patients remained stable (50.0%), two patients were nonresponders (14.3%)]. Fasting glucose values dropped after insulin infusion (-17.7%; p < .001). This effect was maintained during the consecutive OAD treatment period (glucose +0.3%, not significant (NS); HbA1c -6.0%; p < .05). The initial decrease in fasting intact proinsulin levels was also maintained during the study (end value -41%, p < .05). Improvements in hsCRP values (postinsulin value, -15%, NS; end value -37%; p < .05) and adiponectin values (postinsulin value +15%, NS; end value +128%; p < .001) were demonstrated at end point only after continued glitazone intake.

CONCLUSIONS

Our pilot study demonstrated that a beneficial effect of a short-term intravenous insulin application on glycemic control was effectively maintained by pioglitazone/metformin treatment for at least 4 months. In addition, the oral therapy significantly improved cardiovascular risk parameters.