4-benzyl-2-methyl-1-2-4-thiadiazolidine-3-5-dione and Reperfusion-Injury

Topics: Acute Kidney Injury; Animals; Aquaporin 1; Autophagy; Cells, Cultured; Enzyme Inhibitors; Glycogen Synthase Kinase 3 beta; Male; Mice; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Thiadiazoles

Ischemia-reperfusion injury (IRI) is an inevitable consequence of kidney transplantation (KT). The aim of our study was to investigate the protective effect of a glycogen synthase kinase 3β (GSK-3β) inhibitor against cold IRI in a rat renal transplantation (RT) model and a rat cold-IRI model through the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor κ-light-chain-enhancer of the activated B cell (NF-κB) signaling pathway. We treated Sprague Dawley (SD) rats in the RT and cold-IRI models with 5 mg/kg and 1 mg/kg, respectively, of the GSK-3β inhibitor 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8). We then measured inflammatory factors, i.e., tumor necrosis factor alpha (TNF-α) and interleukins-1β and IL-6 (IL-1β, IL-6), as well as oxidative stress markers, i.e., superoxide dismutase (SOD) and malondialdehyde (MDA), in serum and kidneys. Renal function tests and pathological examinations were performed at 0, 1, 2, 3, and 7 days after RT or cold IRI. We measured expression of TLR4, MyD88, inhibitor of NF-κB kinase (IκB), phosphorylated IκB (p-IκB), NF-κB p65, p-p65, GSK-3β, and phosphorylated GSK-3β (p-GSK-3β) by Western blot and immunohistological staining. After intervention with the GSK-3β inhibitor, renal function was improved; oxidative stress injury was reduced; expression of p-GSK-3β was upregulated; expression of p-IκB, TLR4, MyD88, and p-p65 was downregulated; pathological damage was significantly reduced; and expression of TNF-α, IL-1β, and IL-6 messenger ribonucleic acid (mRNA) was downregulated. These results strongly suggested that GSK-3β might be a key target for the treatment of IRI in KT. The GSK-3β inhibitor inhibited phosphorylation of NF-κB p65 and IκB by inhibiting the TLR/MyD88 pathway, reducing oxidative stress injury and the production of downstream inflammatory factors.

Topics: Animals; Glycogen Synthase Kinase 3 beta; Kidney; Kidney Transplantation; Myeloid Differentiation Factor 88; NF-kappa B; Phosphorylation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Thiadiazoles; Toll-Like Receptor 4

Diabetes mellitus can exacerbate renal ischemia-reperfusion (I/R) injury (RI/RI). The aim of the present study was to evaluate the protective effect of GSK-3β inhibition (TDZD-8) on I/R-induced renal injury through the Nrf2/HO-1 pathway in a streptozocin (STZ)-induced diabetic rat model.. STZ-induced diabetic rats preconditioned with TDZD-8 and ZnPP were subjected to renal I/R. The extent of renal morphologic lesions. Renal function was assessed from blood urea nitrogen (BUN) and serum creatinine (Scr), as determined utlizing commercial kits. Oxidative stress and inflammatory activity in the kidney tissue was estimated from levels of malondialdehyde (MDA), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), and nitric oxide (NO), as well as the activities of superoxide dismutase (SOD) and glutathione (GSH) using qRT-PCR and ELISA. The expressions of Nrf2, HO-1, Bcl-2 and NF-κB in the renal tissue were measured by qRT-PCR and western blotting.. I/R-induced renal inflammation was reduced significantly by TDZD-8 pretreatment. Preconditioning with TDZD-8 suppressed NF-κB expression and enhanced Bcl-2 expression in the renal tissue. The upregulated level of malondialdehyde (MDA), and reduced activities of superoxide dismutase (SOD) and glutathione (GSH) in I/R-shocked rats were markedly restored by TDZD-8 pretreatment. Furthermore, pretreatment with TDZD-8 enhanced activation of the Nrf2/HO-1 pathway in the renal tissue of diabetic RI/RI rats.. These findings suggest that preconditioning with TDZD-8 may protect the kidney from I/R-induced damage via the activation of the Nrf2/HO-1 pathway in STZ-induced diabetic rats. Further detailed studies are needed to further clarify the underlying mechanisms.

Topics: Animals; Diabetes Complications; Diabetes Mellitus; Glycogen Synthase Kinase 3 beta; Heme Oxygenase (Decyclizing); Ischemic Preconditioning; Kidney; NF-E2-Related Factor 2; Rats; Reperfusion Injury; Thiadiazoles

Diabetes mellitus (DM) can lead to renal damage and dysfunction, and exacerbate renal ischemia/reperfusion injury (RI/RI). The aim of this study was to investigate the protective effect of GSK-3β inhibitor TDZD-8 against RI/RI through Nrf2/TrxR2 signaling pathway in a rat DM model.. A DM rat model was established by a single injection of streptozocin. Diabetic rats were pretreated with TDZD-8 (1 mg/kg bw) or TDZD-8+auranofin (10 nmol/L, 5ml/kg bw), and then subjected to 45-min ischemia and 24-h reperfusion. Rats were equally randomized into four groups: a Sham-operated group, a RI/RI group, a TDZD-8 group, and a TDZD-8+auranofin group. Serum levels of BUN and Scr were measured. SOD activity, MDA content, and Nrf2, TrxR2 and caspase-3 expressions in rat kidney tissues were determined.. Renal function was improved, oxidative stress and cell apoptosis were reduced, and the expression of Nrf2 and TrxR2 was up-regulated in TDZD-8 treated rats as compared with those in auranofin treated rats.. TDZD-8 may exert its protective effect against RI/RI by regulating the Nrf2/TrxR2 signaling pathway in the kidney tissue in DM.

Topics: Animals; Auranofin; Diabetes Mellitus, Experimental; Disease Models, Animal; Glycogen Synthase Kinase 3 beta; NF-E2-Related Factor 2; Rats; Reperfusion Injury; Signal Transduction; Thiadiazoles; Thioredoxin Reductase 2; Up-Regulation

Glycogen synthase kinase 3 (GSK-3) is a serine-threonine kinase discovered decades ago to have an important role in glycogen metabolism. Today, we know that this kinase is involved in the regulation of many cell functions, including insulin signaling, specification of cell fate during embryonic development, and the control of cell division and apoptosis. Insulin and TDZD-8 (4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione) are inhibitors of GSK-3β that have been shown to possess organ-protective effects in inflammatory-mediated organ injury models. We aimed to evaluate the cytoprotective effect of GSK-3β inhibition on rat models of liver ischemia-reperfusion and thermal injury. In the liver ischemia-reperfusion model, TDZD-8 and insulin were administered at 5 mg/kg (i.v.) and 1.4 IU/kg (i.v.), respectively, 30 min before induction of ischemia and led to the significant reduction of the serum concentration of aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, and lactate dehydrogenase. Beneficial effects were found to be independent from blood glucose levels. In the thermal injury model, TDZD-8 was administered at 5 mg/kg (i.v.) 5 min before induction of injury and significantly reduced multiple organ dysfunction markers (liver, neuromuscular, and lung). In the lung, TDZD-8 reduced the histological signs of tissue injury, inflammatory markers (cytokines), and neutrophil chemotaxis/infiltration; reduced GSK-3β, nuclear factor-κB, and Akt activation; reduced caspase-3 and metalloproteinase-9 activation. Our study provides a new insight on the beneficial effects of GSK-3β inhibition on systemic inflammation and further elucidates the mechanism and pathway crosstalks by which TDZD-8 reduces the multiple organ injury elicited by thermal injury.

Topics: Acute Lung Injury; Animals; Aspartate Aminotransferases; Cell Lineage; Cytokines; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hot Temperature; Humans; Inflammation; Insulin; Liver; Male; Matrix Metalloproteinase 9; Neutrophils; Oxidative Stress; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Reperfusion Injury; Thiadiazoles

Glycogen synthase kinase-3β (GSK3β) is a serine/threonine protein kinase that plays an important role in renal tubular injury and regeneration in acute kidney injury. However, its role in the development of renal fibrosis, often a long-term consequence of acute kidney injury, is unknown. Using a mouse model of renal fibrosis induced by ischemia-reperfusion injury, we demonstrate increased GSK3β expression and activity in fibrotic kidneys, and its presence in myofibroblasts in addition to tubular epithelial cells. Pharmacological inhibition of GSK3 using TDZD-8 starting before or after ischemia-reperfusion significantly suppressed renal fibrosis by reducing the myofibroblast population, collagen-1 and fibronectin deposition, inflammatory cytokines, and macrophage infiltration. GSK3 inhibition in vivo reduced TGF-β1, SMAD3 activation and plasminogen activator inhibitor-1 levels. Consistently in vitro, TGF-β1 treatment increased GSK3β expression and GSK3 inhibition abolished TGF-β1-induced SMAD3 activation and α-smooth muscle actin (α-SMA) expression in cultured renal fibroblasts. Importantly, overexpression of constitutively active GSK3β stimulated α-SMA expression even in the absence of TGF-β1 treatment. These results suggest that TGF-β regulates GSK3β, which in turn is important for TGF-β-SMAD3 signaling and fibroblast-to-myofibroblast differentiation. Overall, these studies demonstrate that GSK3 could promote renal fibrosis by activation of TGF-β signaling and the use of GSK3 inhibitors might represent a novel therapeutic approach for progressive renal fibrosis that develops as a consequence of acute kidney injury.

Topics: Animals; beta Catenin; Cell Differentiation; Cell Line; Epithelial Cells; Extracellular Matrix; Fibroblasts; Fibrosis; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Inflammation Mediators; Kidney; Macrophages; Mice, Inbred C57BL; Myofibroblasts; Protein Kinase Inhibitors; Reperfusion Injury; Signal Transduction; Thiadiazoles; Transforming Growth Factor beta

Diabetes aggravates brain injury after cerebral ischemia/reperfusion (I/R).. To investigate whether limb I/R causes cerebral injury in a rat diabetes model and whether glycogen synthase kinase-3β (GSK-3β) is involved.. Male adult Sprague-Dawley rats were assigned into streptozotocin-induced diabetes (n = 30; blood glucose ≥16.7 mmol/L) or control (n = 20) groups, further subdivided into diabetes I/R (3-hour femoral artery/vein clamping), diabetes-I/R + TDZD-8 (I/R plus GSK-3β inhibitor), diabetes-sham, control-sham and control-I/R groups (n = 10 each). Cortical and hippocampal morphology (hematoxylin/eosin); hippocampal CA1 apoptosis (TUNEL assay); cleaved caspase-3 (apoptosis), and Iba1 (microglial activation) protein expression (immunohistochemistry); phosphorylated/total GSK-3β and nuclear factor-κB (NF-κB) protein levels (Western blotting); and serum and brain tissue tumor necrosis factor (TNF)-α levels (enzyme-linked immunosorbent assay) were analyzed.. The diabetes-I/R group showed greater cortical and hippocampal injury, apoptosis, cleaved caspase-3 expression and Iba1 expression than the control-I/R group; TDZD-8 reduced injury/apoptosis and cleaved caspase-3/Iba1 expressions. The diabetes-I/R group had lower p-GSK-3β and p-NF-κBp65 expression than the control-I/R group (P < 0.05); TDZD-8 increased p-GSK-3β expression but decreased p-NF-κBp65 expression (P < 0.05). The diabetes-I/R group showed higher elevation of serum and brain tissue TNF-α than the control-I/R group (P < 0.05); TDZD-8 reduced TNF-α production.. Diabetes exacerbates limb I/R-induced cerebral damage and activates NF-κB and GSK-3β.

Topics: Animals; Apoptosis; Brain Ischemia; Cerebral Cortex; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Extremities; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hippocampus; Male; NF-kappa B; Rats, Sprague-Dawley; Reperfusion Injury; Thiadiazoles

The mechanism by which the serine-threonine kinase glycogen synthase kinase-3beta (GSK3beta) affects survival of renal epithelial cells after acute stress is unknown. Using in vitro and in vivo models, we tested the hypothesis that GSK3beta promotes Bax-mediated apoptosis, contributing to tubular injury and organ dysfunction after acute renal ischemia. Exposure of renal epithelial cells to metabolic stress activated GSK3beta, Bax, and caspase 3 and induced apoptosis. Expression of a constitutively active GSK3beta mutant activated Bax and decreased cell survival after metabolic stress. In contrast, pharmacologic inhibition (4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione [TDZD-8]) or RNA interference-mediated knockdown of GSK3beta promoted cell survival. Furthermore, RNA interference-mediated knockdown of Bax abrogated the cell death induced by constitutively active GSK3beta. In a cell-free assay, TDZD-8 inhibited the phosphorylation of a peptide containing the Bax serine(163) site targeted by stress-activated GSK3beta. In rats, TDZD-8 inhibited ischemia-induced activation of GSK3beta, Bax, and caspase 3; ameliorated tubular and epithelial cell damage; and significantly protected renal function. Taken together, GSK3beta-mediated Bax activation induces apoptosis and tubular damage that contribute to acute ischemic kidney injury.

Topics: Acute Kidney Injury; Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Cell Line; Epithelial Cells; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Kidney Tubules, Proximal; Male; Mice; Rats; Rats, Sprague-Dawley; Reperfusion Injury; RNA Interference; Thiadiazoles

Recent studies on the mechanisms of ischemic preconditioning in myocardial tissue have presented convincing evidence that multiple protective pathways converge on inhibition of glycogen synthase kinase-3β (GSK-3β). To directly address the role of GSK-3β in ischemia and reperfusion (I/R) of the lung, a rat model of left lung in situ ischemia was used. The specific non-competitive inhibitor of GSK-3β, TDZD-8, was injected (3 mg/kg, vehicle in controls) 5 min before the left lung hilum was occluded for 60 min. Animals in the ischemia group underwent the same treatment, but without administration of TDZD-8. Lung functional and biochemical parameters were determined at time points 15 min and 60 min reperfusion. Treatment with TDZD-8 improved gas exchange (arterial pO2), but I/R-induced inflammation (plasma interleukin-6, leukocyte invasion) was not affected. The I/R cycle induced a rapid (15 min reperfusion) increase of protein tyrosine phosphorylation, including the activating phosphorylation of focal adhesion kinase at Tyr397, Tyr407, Tyr577, and Tyr861, and the non-receptor kinase Src at Tyr416. The phosphorylation was blocked by the GSK inhibitor. This effect may be related to the reduced plasma level of the strong effector of focal adhesion kinase, transforming growth factor-β1, in the TDZD group. The underlying mechanisms are elusive, but they deserve further investigation, especially in relation to the early increase of lung permeability in this rat model of I/R injury. In conclusion, the results suggest that inhibition of GSK-3β improves rat lung function during an I/R cycle, but only during the early reperfusion phase.

Topics: Animals; Enzyme Activation; Enzyme Inhibitors; Focal Adhesion Protein-Tyrosine Kinases; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Lung; Phosphorylation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; src-Family Kinases; Thiadiazoles

There is evidence that insulin reduces brain injury evoked by ischemia/reperfusion (I/R). However, the molecular mechanisms underlying the protective effects of insulin remain unknown. Insulin is a well-known inhibitor of glycogen synthase kinase-3beta (GSK-3beta). Here, we investigate the role of GSK-3beta inhibition on I/R-induced cerebral injury in a rat model of insulinopenic diabetes.. Rats with streptozotocin-induced diabetes were subjected to 30-min occlusion of common carotid arteries followed by 1 or 24 h of reperfusion. Insulin (2-12 IU/kg i.v.) or the selective GSK-3beta inhibitor TDZD-8 (0.2-3 mg/kg i.v.) was administered during reperfusion.. Insulin or TDZD-8 dramatically reduced infarct volume and levels of S100B protein, a marker of cerebral injury. Both drugs induced phosphorylation of the Ser9 residue, thereby inactivating GSK-3beta in the rat hippocampus. Insulin, but not TDZD-8, lowered blood glucose. The hippocampi of the drug-treated animals displayed reduced oxidative stress at 1 h of reperfusion as shown by the decreased generation of reactive oxygen species and lipid peroxidation. I/R-induced activation of nuclear factor-kappaB was attenuated by both drug treatments. At 24 h of reperfusion, TDZD-8 and insulin significantly reduced plasma levels of tumor necrosis factor-alpha; neutrophil infiltration, measured as myeloperoxidase activity and intercellular-adhesion-molecule-1 expression; and cyclooxygenase-2 and inducible-NO-synthase expression.. Acute administration of insulin or TDZD-8 reduced cerebral I/R injury in diabetic rats. We propose that the inhibitory effect on the activity of GSK-3beta contributes to the protective effect of insulin independently of any effects on blood glucose.

Topics: Animals; Blood Glucose; Blotting, Western; Body Weight; Brain Ischemia; Diabetes Mellitus, Experimental; Enzyme-Linked Immunosorbent Assay; Gene Expression; Glycogen Synthase Kinase 3; Hippocampus; Hormones; Hypoglycemic Agents; Insulin; Lipid Peroxidation; Male; NF-kappa B; Oxidative Stress; Phosphorylation; Rats; Rats, Wistar; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; Thiadiazoles; Tumor Necrosis Factor-alpha

The serine/threonine glycogen synthase kinase 3beta (GSK-3beta) is abundant in the central nervous system, particularly in the hippocampus, and plays a pivotal role in the pathophysiology of a number of diseases, including neurodegeneration. This study was designed to investigate the effects of GSK-3beta inhibition against I/R injury in the rat hippocampus. Transient cerebral ischemia (30 min) followed by 1 h of reperfusion significantly increased generation of reactive oxygen species and modulated superoxide dismutase activity; 24 h of reperfusion evoked apoptosis (determined as mitochondrial cytochrome c release and Bcl-2 and caspase-9 expression), resulted in high plasma levels of TNF-alpha and increased expression of cyclooxygenase-2, inducible nitric oxide synthase, and intercellular adhesion molecule-1. The selective GSK-3beta inhibitor, 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), was administered before and after ischemia or during reperfusion alone to assess its potential as prophylactic or therapeutic strategy. Prophylactic or therapeutic administration of TDZD-8 caused the phosphorylation (Ser(9)) and hence inactivation of GSK-3beta. Infarct volume and levels of S100B protein, a marker of cerebral injury, were reduced by TDZD-8. This was associated with a significant reduction in markers of oxidative stress, apoptosis, and the inflammatory response resulting from cerebral I/R. These beneficial effects were associated with a reduction of I/R-induced activation of the mitogen-activated protein kinases JNK1/2 and p38 and nuclear factor-kappaB. The present study demonstrates that TDZD-8 protects the brain against I/R injury by inhibiting GSK-3beta activity. Collectively, our data may contribute to focus the role of GSK-3beta in cerebral I/R.

Topics: Animals; Antioxidants; Brain; Brain Ischemia; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hippocampus; Male; Mitochondria; Models, Biological; Nerve Growth Factors; Phosphorylation; Rats; Rats, Wistar; Reperfusion Injury; S100 Calcium Binding Protein beta Subunit; S100 Proteins; Thiadiazoles

This study investigated the effects of TDZD-8, a potent and selective GSK-3beta inhibitor, on tissue injury caused by ischaemia/reperfusion (I/R) of the gut.. Animal study in the Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina, Italy.. Splanchnic artery occlusion (SAO) shocked rats.. I/R injury of the intestine was caused by clamping both the superior mesenteric artery and the coeliac trunk for 45 min followed by release of the clamp allowing reperfusion for 1 or 6 h. This procedure results in SAO shock.. Only 10% of the SAO animals survived the entire 6 h reperfusion period. In a separate set of experiments after 60 min of reperfusion animals were killed for histological examination and biochemical studies. Administration of TDZD-8 (1 mg/kg i.v.) 5 min prior to the reperfusion significantly reduced the (a) fall in mean arterial blood pressure, (b) mortality rate, (c) infiltration of the reperfused intestine with polymorphonuclear neutrophils (MPO activity), (d) production of pro-inflammatory cytokines (TNF-alpha and IL-1 beta and (e) histological evidence of gut injury. Administration of TDZD-8 also markedly reduced the immunoreactivity of nitrotyrosine formation and the expression of ICAM-1 and P-selectin during reperfusion.. Based on these findings we propose that TDZD-8 would be useful in the treatment of various ischaemia and reperfusion diseases.

Topics: Animals; Cytokines; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Ileum; In Situ Nick-End Labeling; Male; Malondialdehyde; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Splanchnic Circulation; Thiadiazoles