Omentin-1 attenuates lipopolysaccharide (LPS)-induced U937 macrophages activation by inhibiting the TLR4/MyD88/NF-κB signaling
Macrophages play a pivotal role in the defense response against harmful pathogens and stimuli by releasing various pro-inflammatory mediators. However, overproduction of pro-inflammatory mediators will do harm to the organism and cause inflammation-associated diseases. Omentin-1, which is a newly discovered adipokine, is specifically expressed in omental adipose tissue. Recent studies have found correlations between omentin-1 and insulin resistance, diabetes, obesity, inflammation, atherosclerosis, bone metabolism, and tumor cell proliferation. Some studies have shown that the association between omentin-1, insulin resistance, and inflammation might suggest that omentin-1 plays an important role in chronic inflammatory diseases. In this study, we found that omentin-1 inhibited LPS-induced expression of inflammatory mediators and pro-inflammatory cytokines in macrophages. Furthermore, omentin-1 inhibited activation of the NF-κB pathway by suppressing both nuclear p65 accumulation and transfected NFκB promoter activity. Importantly, omentin-1 increased nuclear translocation of Nrf2. Our findings demonstrate that omentin-1 exerts anti-inflammatory effects on LPS-induced macrophages and has potential implication in the treatment of inflammation-associated diseases.
Nrf2: Redox and Metabolic Regulator of Stem Cell State and Function
Nuclear factor erythroid 2-related factor 2 (Nrf2) is ubiquitously expressed in most eukaryotic cells and functions to induce a broad range of cellular defenses against exogenous and endogenous stresses, including oxidants, xenobiotics, and excessive nutrient/metabolite supply. Because the production and fate of stem cells are often modulated by cellular redox and metabolic homeostasis, important roles of Nrf2 have emerged in the regulation of stem cell quiescence, survival, self-renewal, proliferation, senescence, and differentiation. In a rapidly advancing field, this review summarizes Nrf2 signaling in the context of stem cell state and function and provides a rationale for Nrf2 as a therapeutic target in stem cell-based regenerative medicine.
Renoprotective effect of calycosin in high fat diet-fed/STZ injected rats: Effect on IL-33/ST2 signaling, oxidative stress and fibrosis suppression
Type 2 diabetes mellitus (T2DM) is a disease with a drastically growing worldwide prevalence. It is usually associated with numerous complications of which; diabetic nephropathy (DN); is a main complication of microvasculature and more seriously, a common cause of end-stage renal disease (ESRD). Unfortunately, both the lack of a definitive remedy alongside the economic and the social burden on DN patients enforces considerable impetus for developing alternative therapies. IL-33 is a newly discovered member of the IL-1 cytokine family. IL33/ST2 signaling plays a crucial role in acute and chronic kidney diseases. Calycosin is an isoflavone with reported IL33 signaling inhibitory activity. The present study aimed to investigate if calycosin possess renal protective effect in high-fat diet/STZ-induced T2DM model and to clarify the potential underlying mechanisms. HFD-STZ control rats showed functional and structural renal damage confirmed by increased serum creatinine, blood urea nitrogen and albuminuria associated with marked renal glomerulosclerosis and interstitial fibrosis. Initiation of inflammation, oxidative stress, and fibrosis was evident as depicted by elevated renal levels of IL33/ST2 mRNA as well as increased renal NF-κBp65, TNF-α, IL-1β, MDA, and TGF-β contents with suppressed Nrf2 and TAC. Calycosin treatment markedly improved the aforementioned makers of renal injury and dysfunction, modulated IL33/ST2 signaling, inflammatory cytokines, oxidative stress and fibrotic processes. This was accompanied by improvement of T2DM-induced renal ultramicroscopic and histopathological alterations.
Protective effects of sulforaphane on type 2 diabetes-induced cardiomyopathy via AMPK-mediated activation of lipid metabolic pathways and NRF2 function
AMP-activated protein kinase (AMPK), particularly AMPKα2 isoform, plays a critical role in maintaining cardiac homeostasis. It was reported that sulforaphane (SFN) prevented type 2 diabetes (T2D)-induced cardiomyopathy accompanied by the activation of AMPK; In this study, AMPK's pivotal role in SFN-mediated prevention against T2D-induced cardiomyopathy was tested using global deletion of AMPKα2 gene (AMPKα2-KO) mice.
Investigation of Molecular Details of Keap1-Nrf2 Inhibitors Using Molecular Dynamics and Umbrella Sampling Techniques
In this study, we investigate the atomistic details of Keap1-Nrf2 inhibitors by in-depth modeling techniques, including molecular dynamics (MD) simulations, and the path-based free energy method of umbrella sampling (US). The protein-protein interaction (PPI) of Keap1-Nrf2 is implicated in several neurodegenerative diseases like cancer, diabetes, and cardiomyopathy. A better understanding of the five sub-pocket binding sites for Nrf2 (ETGE and DLG motifs) inside the Kelch domain would expedite the inhibitor design process. We selected four protein-ligand complexes with distinct co-crystal ligands and binding occupancies inside the Nrf2 binding site. We performed 100 ns of MD simulation for each complex and analyzed the trajectories. From the results, it is evident that one ligand (1VV) has flipped inside the binding pocket, whereas the remaining three were stable. We found that Coulombic (Arg483, Arg415, Ser363, Ser508, and Ser602) and Lennard-Jones (Tyr525, Tyr334, and Tyr572) interactions played a significant role in complex stability. The obtained binding free energy values from US simulations were consistent with the potencies of simulated ligands. US simulation highlight the importance of basic and aromatic residues in the binding pocket. A detailed description of the dissociation process brings valuable insight into the interaction of the four selected protein-ligand complexes, which could help in the future to design more potent PPI inhibitors.
Intra-pancreatic tissue-derived mesenchymal stromal cells: a promising therapeutic potential with anti-inflammatory and pro-angiogenic profiles
Human pancreata contain many types of cells, such as endocrine islets, acinar, ductal, fat, and mesenchymal stromal cells (MSCs). MSCs are important and shown to have a promising therapeutic potential to treat various disease conditions.
Design and optimization strategies for the development of new drugs that treat chronic kidney disease
: Chronic kidney disease (CKD) is characterized by increased risks of progression to end-stage kidney disease requiring dialysis and cardiovascular mortality, predicted to be among the five top causes of death by 2040. Only the design and optimization of novel strategies to develop new drugs to treat CKD will contain this trend. Current therapy for CKD includes nonspecific therapy targeting proteinuria and/or hypertension and cause-specific therapies for diabetic kidney disease, autosomal dominant polycystic kidney disease, glomerulonephritides, Fabry nephropathy, hemolytic uremic syndrome and others.: Herein, the authors review the literature on new drugs under development for CKD as well as novel design and development strategies.: New therapies for CKD have become a healthcare priority. Emerging therapies undergoing clinical trials are testing expanded renin-angiotensin system blockade with double angiotensin receptor/endothelin receptor blockers, SGLT2 inhibition, and targeting inflammation, the immune response, fibrosis and the Nrf2 transcription factor. Emerging therapeutic targets include cell senescence, complement activation, Klotho expression preservation and microbiota. Novel approaches include novel model systems that can be personalized (e.g. organoids), unbiased systems biology-based identification of new therapeutic targets, drug databases that speed up drug identification and repurposing, nanomedicines that improve drug delivery and RNA targeting to expand the number of targetable proteins.
Ginsenoside Rg1 protects mice against streptozotocin-induced type 1 diabetic by modulating the NLRP3 and Keap1/Nrf2/HO-1 pathways
Ginseng has been traditionally used to treat diabetes mellitus (DM) in China. Ginsenoside Rg1 is a major active ingredient in processed ginseng, which elicits proven biological and pharmacological effects. Although a correlation between nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and predisposition to type 1 diabetes mellitus (T1DM) has been identified, the mechanism underlying the potential function and activation of NLRP3 inflammasome in DM have not been elucidated to date. The present study aimed to elucidate the effects and underlying mechanism of Rg1 on streptozotocin (STZ)-induced T1DM in mice through short or long-term observation. Concurrently, we intended to explore the relationships between inflammasome, pyroptosis and oxidative stress and the role of NLRP3 and Keap1/Nrf2/HO-1 pathways in the development and progression of DM. Using ELISA and Western blot analysis, we found that Rg1 attenuated abnormally elevated blood glucose, reduced inflammatory factors IL-1β and IL-18 in the blood, decreased ALT and AST levels, promoted insulin secretion, and weakened the function of NLRP3 in mouse liver and pancreas. In addition, Rg1 protected against STZ-induced reactive oxygen species-mediated inflammation by upregulating Nrf2/ARE pathway, which further activated antioxidant enzymes. Interestingly, Rg1 also regulated H3K9 methylation in liver and pancreas, as detected by immunohistochemistry. In summary, these data provide new understanding about the mechanism of Rg1 action, suggesting that it is a potential drug applied for preventing the occurrence and development of T1DM.
A novel compound AB38b attenuates oxidative stress and ECM protein accumulation in kidneys of diabetic mice through modulation of Keap1/Nrf2 signaling
Extracellular matrix (ECM) deposition following reactive oxygen species (ROS) overproduction has a key role in diabetic nephropathy (DN), thus, antioxidant therapy is considered as a promising strategy for treating DN. Here, we investigated the therapeutic effects of AB38b, a novel synthetic α, β-unsaturated ketone compound, on the oxidative stress (OS) and ECM accumulation in type 2 diabetes mice, and tried to clarify the mechanisms underlying the effects in high glucose (HG, 30 mM)-treated mouse glomerular mesangial cells (GMCs). Type 2 diabetes model was established in mice with high-fat diet feeding combined with streptozocin intraperitoneal administration. The diabetic mice were then treated with AB38b (10, 20, 40 mg· kg· d, ig) or a positive control drug resveratrol (40 mg· kg· d, ig) for 8 weeks. We showed that administration of AB38b or resveratrol prevented the increases in malondialdehyde level, lactate dehydrogenase release, and laminin and type IV collagen deposition in the diabetic kidney. Simultaneously, AB38b or resveratrol markedly lowered the level of Keap1, accompanied by evident activation of Nrf2 signaling in the diabetic kidney. The underlying mechanisms of antioxidant effect of AB38b were explored in HG-treated mouse GMCs. AB38b (2.5-10 μM) or resveratrol (10 μM) significantly alleviated OS and ECM accumulation in HG-treated GMCs. Furthermore, AB38b or resveratrol treatment effectively activated Nrf2 signaling by inhibiting Keap1 expression without affecting the interaction between Keap1 and Nrf2. Besides, AB38b treatment effectively suppressed the ubiquitination of Nrf2. Taken together, this study demonstrates that AB38b ameliorates experimental DN through antioxidation and modulation of Keap1/Nrf2 signaling pathway.
Involvement of Estrogen Receptor-α in the Activation of Nrf2-Antioxidative Signaling Pathways by Silibinin in Pancreatic β-Cells
Silibinin exhibits antidiabetic potential by preserving the mass and function of pancreatic β-cells through up-regulation of estrogen receptor-α (ERα) expression. However, the underlying protective mechanism of silibinin in pancreatic β-cells is still unclear. In the current study, we sought to determine whether ERα acts as the target of silibinin for the modulation of antioxidative response in pancreatic β-cells under high glucose and high fat conditions. Our study revealed that a 4-week oral administration of silibinin (100 mg/kg/day) decreased fasting blood glucose with a concurrent increase in levels of serum insulin in high-fat diet/streptozotocin- induced type 2 diabetic rats. Moreover, expression of ERα, NF-E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) in pancreatic β-cells in pancreatic islets was increased by silibinin treatment. Accordingly, silibinin (10 μM) elevated viability, insulin biosynthesis, and insulin secretion of high glucose/palmitate-treated INS-1 cells accompanied by increased expression of ERα, Nrf2, and HO-1 as well as decreased reactive oxygen species production in vitro. Treatment using an ERα antagonist (MPP) in INS-1 cells or silencing ERα expression in INS-1 and NIT-1 cells with siRNA abolished the protective effects of silibinin. Our study suggests that silibinin activates the Nrf2-antioxidative pathways in pancreatic β-cells through regulation of ERα expression.
Chaperone-Mediated Autophagy in the Liver: Good or Bad?
Hepatitis C virus (HCV) infection triggers autophagy processes, which help clear out the dysfunctional viral and cellular components that would otherwise inhibit the virus replication. Increased cellular autophagy may kill the infected cell and terminate the infection without proper regulation. The mechanism of autophagy regulation during liver disease progression in HCV infection is unclear. The autophagy research has gained a lot of attention recently since autophagy impairment is associated with the development of hepatocellular carcinoma (HCC). Macroautophagy, microautophagy, and chaperone-mediated autophagy (CMA) are three autophagy processes involved in the lysosomal degradation and extracellular release of cytosolic cargoes under excessive stress. Autophagy processes compensate for each other during extreme endoplasmic reticulum (ER) stress to promote host and microbe survival as well as HCC development in the highly stressed microenvironment of the cirrhotic liver. This review describes the molecular details of how excessive cellular stress generated during HCV infection activates CMA to improve cell survival. The pathological implications of stress-related CMA activation resulting in the loss of hepatic innate immunity and tumor suppressors, which are most often observed among cirrhotic patients with HCC, are discussed. The oncogenic cell programming through autophagy regulation initiated by a cytoplasmic virus may facilitate our understanding of HCC mechanisms related to non-viral etiologies and metabolic conditions such as uncontrolled type II diabetes. We propose that a better understanding of how excessive cellular stress leads to cancer through autophagy modulation may allow therapeutic development and early detection of HCC.
Codonopsis lanceolata polysaccharide CLPS alleviates high fat/high sucrose diet-induced insulin resistance via anti-oxidative stress
Polysaccharide has been considered as an important bioactive compound in Codonopsis lanceolata. High fat/high sucrose (HFHS) diet-induced insulin resistance is implicated in multiple metabolic diseases, such as type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD), these metabolic diseases has become epidemic health issue worldwide. In this study, the effect of C. lanceolata polysaccharide (CLPS) on improving insulin sensitivity in chronic HFHS diet-fed mice was investigated. Our data indicates that CLPS significantly reduced fasting blood glucose (FBG), fasting serum insulin (FINS) and insulin resistance index, in parallel with improved glucose and insulin tolerance impaired by HFHS diet. Impaired phosphorylation of PKB/Akt and hyperphosphorylation of IRS-1 at Ser307 were observed in the mice fed with HFHS diet, and those defects were also rescued by CLPS administration. In addition, CLPS caused a significant decrease in the level of malondialdehyde (MDA), and an increase in reduced glutathione (GSH)/oxidised glutathione (GSSG) ratio; concurrent with enhanced expression of antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT), and activated Nrf2 signaling. In summary, these findings suggest that CLPS ameliorates HFHS diet-induced insulin resistance through activating anti-oxidative signaling pathway, providing new insights into the protective effects of C. lanceolata polysaccharide in metabolic disease.
LncRNA Blnc1 expression and its effect on renal fibrosis in diabetic nephropathy
Diabetic nephropathy (DN) is one of the commonest microvascular complications of diabetes and has been the major cause of end-stage renal disease in many countries. It is of great clinical significance to further explore more efficacious therapeutic strategies for DN. This study aims to explore the effect of Blnc1 on renal fibrosis in diabetic nephropathy.
Editorial: Role of Nrf2 in Disease: Novel Molecular Mechanisms and Therapeutic Approaches
Antidiabetic, Antihyperlipidemic, Antioxidant, Anti-inflammatory Activities of Ethanolic Seed Extract of L. in Streptozotocin Induced Diabetic Rats
L. (Bullock's heart) is a pantropic tree commonly known as custard apple, which is used therapeutically for a variety of maladies. The present research was carried out to evaluate the possible protective effects of L. () ethanolic seed extract on an experimentally induced type 2 diabetes rat model. Male Albino Wistar rats were randomly divided into five groups with six animals in each group viz., control rats in group I, diabetic rats in group II, diabetic rats with 50 and 100 mg/kg/bw of ethanolic seed extract of in groups III and IV, respectively, and diabetic rats with metformin in group V. Treatment was given for 42 consecutive days through oral route by oro-gastric gavage. Administration of seed extract to diabetes rats significantly restored the alterations in the levels of body weight, food and water intake, fasting blood glucose (FBG), insulin levels, insulin sensitivity, HbA1c, HOMA-IR, islet area and insulin positive cells. Furthermore, significantly decreased the levels of triglycerides, cholesterol, LDL, and significantly increased the HDL in diabetic rats. effectively ameliorated the enzymatic (ALT, AST, ALP, GGT) and modification of histopathological changes in diabetic rats. The serum levels of the BUN, creatinine levels, uric acid, urine volume, and urinary protein were significantly declined with a significant elevation in CCr in diabetic rats treated with . MDA and NO levels were significantly reduced with an enhancement in SOD, CAT, and GPx antioxidant enzyme activities in the kidney, liver, and pancreas of diabetic rats treated with . Diabetic rats treated with have shown up-regulation in mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase 1 (NQO1), Heme oxygenase-1 (HO-1) and protein expression level of Nrf2 with diminution in Keap1 mRNA expression level in pancreas, kidney, and liver. From the outcome of the current results, it can be inferred that seed extract of exhibits a protective effect in diabetic rats through its anti-diabetic, anti-hyperlipidemic, antioxidant and anti-inflammatory effects and could be considered as a promising treatment therapy in the treatment of diabetes mellitus.