High glucose induces renal mesangial cell proliferation and fibronectin expression through JNK/NF-κB/NADPH oxidase/ROS pathway, which is inhibited by resveratrol

Role of mitochondria in pathogenesis and therapy of renal fibrosis

Renal fibrosis, specifically tubulointerstitial fibrosis, represents the predominant pathological consequence observed in the context of progressive chronic kidney conditions. The pathogenesis of renal fibrosis encompasses a multifaceted interplay of mechanisms, including but not limited to interstitial fibroblast proliferation, activation, augmented production of extracellular matrix (ECM) components, and impaired ECM degradation. Notably, mitochondria, the intracellular organelles responsible for orchestrating biological oxidation processes in mammalian cells, assume a pivotal role within this intricate milieu. Mitochondrial dysfunction, when manifest, can incite a cascade of events, including inflammatory responses, perturbed mitochondrial autophagy, and associated processes, ultimately culminating in the genesis of renal fibrosis. This comprehensive review endeavors to furnish an exegesis of mitochondrial pathophysiology and biogenesis, elucidating the precise mechanisms through which mitochondrial aberrations contribute to the onset and progression of renal fibrosis. We explored how mitochondrial dysfunction, mitochondrial cytopathy and mitochondrial autophagy mediate ECM deposition and renal fibrosis from a multicellular perspective of mesangial cells, endothelial cells, podocytes, macrophages and fibroblasts. Furthermore, it succinctly encapsulates the most recent advancements in the realm of mitochondrial-targeted therapeutic strategies aimed at mitigating renal fibrosis.

Resveratrol protects mesangial cells under high glucose by regulating the miR-1231/IGF1/ERK pathway

Diabetic nephropathy (DN) is one of the complications of diabetes mellitus and the main cause of end-stage renal disease (ESRD), which is a serious threat to human health. In DN, mesangial cells (MCs) are a critical target cell that perform a variety of key functions, and abnormal proliferation of MCs is a common and prominent pathological change in DN. In recent years, the investigation of Chinese medicine interventions for DN has increased significantly in recent years due to the many potential adverse effects and controversies associated with the treatment of DN with Western medicines. In this study, we evaluated the protective effect of resveratrol (RES), an active ingredient known as a natural antioxidant, on HMCs under high glucose and explored its possible mechanism of action. We found that RES inhibited the proliferation of human mesangial cell (HMC) under high glucose and blocked cell cycle progression. In the high glucose environment, RES upregulated miR-1231, reduced IGF1 expression, inhibited the activity of the extracellular signal-regulated kinase (ERK) signaling pathway and reduced levels of the inflammatory factors TNF-α and IL-6. In addition, we found that miR-1231 mimics were synergistically inhibited with RES, whereas miR-1231 inhibitor attenuated the protective effect of RES on HMCs. Thus, our results suggest that the protective effect of RES on HMCs under high glucose is achieved, at least in part, through modulation of the miR-1231/IGF1/ERK pathway. The discovery of this potential mechanism may provide a new molecular therapeutic target for the prevention and treatment of DN, and may also bring new ideas for the clinical research in DN.

Nuclear respiratory factor 1 regulates super enhancer-controlled SPIDR to protect hepatocellular carcinoma cells from oxidative stress

BACKGROUND

Cellular response to oxidative stress plays significant roles in hepatocellular carcinoma (HCC) development, yet the exact mechanism by which HCC cells respond to oxidative stress remains poorly understood. This study aimed to investigate the role and mechanism of super enhancer (SE)-controlled genes in oxidative stress response of HCC cells.

METHODS

The GSE112221 dataset was used to identify SEs by HOMER. Functional enrichment of SE-controlled genes was performed by Metascape. Transcription factors were predicted using HOMER. Prognosis analysis was conducted using the Kaplan-Meier Plotter website. Expression correlation analysis was performed using the Tumor Immune Estimation Resource web server. NRF1 and SPIDR expression in HCC and normal liver tissues was analyzed based on the TCGA-LIHC dataset. ChIP-qPCR was used to detect acetylation of lysine 27 on histone 3 (H3K27ac) levels of SE regions of genes, and the binding of NRF1 to the SE of SPIDR. To mimic oxidative stress, HepG2 and Hep3B cells were stimulated with H2O2. The effects of NRF1 and SPIDR on the oxidative stress response of HCC cells were determined by the functional assays.

RESULTS

A total of 318 HCC-specific SE-controlled genes were identified. The functions of these genes was significant association with oxidative stress response. SPIDR and RHOB were enriched in the "response to oxidative stress" term and were chosen for validation. SE regions of SPIDR and RHOB exhibited strong H3K27ac modification, which was significantly inhibited by JQ1. JQ1 treatment suppressed the expression of SPIDR and RHOB, and increased reactive oxygen species (ROS) levels in HCC cells. TEAD2, TEAD3, NRF1, HINFP and TCFL5 were identified as potential transcription factors for HCC-specific SE-controlled genes related to oxidative stress response. The five transcription factors were positively correlated with SPIDR expression, with the highest correlation coefficient for NRF1. NRF1 and SPIDR expression was up-regulated in HCC tissues and cells. NRF1 activated SPIDR transcription by binding to its SE. Silencing SPIDR or NRF1 significantly promoted ROS accumulation in HCC cells. Under oxidative stress, silencing SPIDR or NRF1 increased ROS, malondialdehyde (MDA) and γH2AX levels, and decreased superoxide dismutase (SOD) levels and cell proliferation of HCC cells. Furthermore, overexpression of SPIDR partially offset the effects of NRF1 silencing on ROS, MDA, SOD, γH2AX levels and cell proliferation of HCC cells.

CONCLUSION

NRF1 driven SPIDR transcription by occupying its SE, protecting HCC cells from oxidative stress-induced damage. NRF1 and SPIDR are promising biomarkers for targeting oxidative stress in the treatment of HCC.

Resveratrol may mildly improve renal function in the general adult population: A systematic review and meta-analysis of randomized controlled clinical trials

Whether renal health biomarkers can benefit from resveratrol supplements is unknown. Thus, we conducted a systematic review and meta-analysis to summarize evidence from randomized controlled trials investigating the effect of resveratrol supplementation on renal health biomarkers. We hypothesized that resveratrol supplementation is associated with improved renal health biomarkers. Four electronic databases, including PubMed, Scopus, and Institute for Scientific Information Web of Science, and Cochrane Central, were searched for relevant articles up to February 2023. The pooled effect sizes were estimated using a random effects model and expressed as weighted mean difference (WMD) and 95% CI. In total, 32 articles were eligible for inclusion in the current meta-analysis. The pooled results indicated that resveratrol significantly decreased blood urea nitrogen (weighted mean difference [WMD]= -0.84 mg/dL; 95% CI, -1.48 to -0.20; P = .01; I² = 64.4%) and creatinine levels (WMD = -1.90 µmol/L; 95% CI, -3.59 to -0.21; P = .03; I²= 52.1%), and increased glomerular filtration rate (WMD = 7.58 mL/min/1.73 m²; 95% CI, 5.25-9.91; P < .001; I² = 0%). The favorable change of blood urea nitrogen was significant in studies with short follow-up duration (12 weeks or less), with lower doses of resveratrol (less than 500 mg/d), and those conducted in patients with diabetes. However, higher doses of resveratrol are needed to observe significant reductions in creatinine. No significant change was observed in albumin, total protein, and uric acid concentrations. This meta-analysis provides a low certainty of evidence indicating a mild renal protective effect of resveratrol in adults. Further high-quality evidence in patients with impaired renal function and estimates of mortality risk in these patients is required before resveratrol can be advocated as an adjuvant therapy.

Blue LED light induces cytotoxicity via ROS production and mitochondrial damage in bovine subcutaneous preadipocytes

The purpose of this study was to investigate the effect and mechanism of blue light irradiation on bovine subcutaneous preadipocytes. In this study, preadipocytes were divided into dark group (control) and blue light group. Results show that blue light exposure time-dependently reduced the viability of preadipocytes and induced mitochondrial damage, in accompaniment with the accumulation of intracellular reactive oxygen species (ROS). Meanwhile, blue light caused oxidative stress, as evidenced by the increased MDA level, the reduced T-AOC contents, as well as the decreased activities of antioxidant enzymes. Additionally, blue light treatment induced apoptosis and G2/M phase arrest via Bcl-2/Bax/cleaved caspase-3 pathway and P53/GADD45 pathway, respectively. Protein expressions of LC3-II/LC3-I and P62 were up-regulated under blue light exposure, indicating blue light initiated autophagy but impeded autophagic degradation. Moreover, blue light caused an increase in the secretion of pro-inflammatory factors (TNF-α, IL-1β, and IL-6). Pretreatment with N-acetylcysteine (NAC), a potent ROS scavenger, restored the loss of mitochondrial membrane potential (Δψ) and reduced excess ROS. Additionally, the above negative effects of blue light on cells were alleviated after NAC administration. In conclusion, this study demonstrates blue light induces cellular ROS overproduction and Δψ depolarization, resulting in the decrease of cell viability and the activation of apoptosis, autophagy, and inflammation, providing a reference for the application of blue light in the regulation of fat cells in the future.

Fibronectin-Enriched Interface Using a Spheroid-Converged Cell Sheet for Effective Wound Healing

Cell sheets and spheroids are cell aggregates with excellent tissue-healing effects. However, their therapeutic outcomes are limited by low cell-loading efficacy and low extracellular matrix (ECM). Preconditioning cells with light illumination has been widely accepted to enhance reactive oxygen species (ROS)-mediated ECM expression and angiogenic factor secretion. However, there are difficulties in controlling the amount of ROS required to induce therapeutic cell signaling. Here, we develop a microstructure (MS) patch that can culture a unique human mesenchymal stem cell complex (hMSCcx), spheroid-attached cell sheets. The spheroid-converged cell sheet structure of hMSCcx shows high ROS tolerance compared to hMSC cell sheets owing to its high antioxidant capacity. The therapeutic angiogenic efficacy of hMSCcx is reinforced by regulating ROS levels without cytotoxicity using light (610 nm wavelength) illumination. The reinforced angiogenic efficacy of illuminated hMSCcx is based on the increased gap junctional interaction by enhanced fibronectin. hMSCcx engraftment is significantly improved in our novel MS patch by means of ROS tolerative structure of hMSCcx, leading to robust wound-healing outcomes in a mouse wound model. This study provides a new method to overcome the limitations of conventional cell sheets and spheroid therapy.

Abnormalities in sex hormones and sexual dysfunction in males with diabetes mellitus: A mechanistic insight

Diabetes is a considerate metabolic disorder that can lead to a series of complications, involving the malfunctioning of the reproductive system of males. It has been observed that there is a gradual rise in male diabetic patients and almost half of the diabetic males have low semen quality and decrease reproductive function. In diabetic conditions, prolonged hyperglycemia leads to oxidative stress, diabetic neuropathy, and insulin resistance. Insulin resistance and its deficiency can impair the hypothalamus, pituitary gland, gonads, and perigonads. This causes a decrease in the secretion of gonadal steroids such as GnRH (gonadotropin-releasing hormone), FSH (follicle-stimulating hormone), LH (luteinizing hormone), and Testosterone. Moreover, it also causes damage to the testicles, spermatogenic and stromal cells, seminiferous tubules, and various structural injuries to male reproductive organs. During spermatogenesis, glucose metabolism plays an important role, because the fundamental activities of cells and their specific features, such as motility and mature sperm fertilization activity, are maintained by glucose metabolism. All these activities can influence the fertility and reproductive health of males. But the glucose metabolism is primarily disrupted in diabetic conditions. Until now, there has been no medicine focusing on the reproductive health of diabetic people. In this chapter, we review the consequences of diabetes on the reproductive system of males and all the pathways involved in the dysfunction of the reproductive system. This will help interpret the effects of DM on male reproductive health.

Glucosidase inhibitor, Nimbidiol ameliorates renal fibrosis and dysfunction in type-1 diabetes

Diabetic nephropathy is characterized by excessive accumulation of extracellular matrix (ECM) leading to renal fibrosis, progressive deterioration of renal function, and eventually to end stage renal disease. Matrix metalloproteinases (MMPs) are known to regulate synthesis and degradation of the ECM. Earlier, we demonstrated that imbalanced MMPs promote adverse ECM remodeling leading to renal fibrosis in type-1 diabetes. Moreover, elevated macrophage infiltration, pro-inflammatory cytokines and epithelial‒mesenchymal transition (EMT) are known to contribute to the renal fibrosis. Various bioactive compounds derived from the medicinal plant, Azadirachta indica (neem) are shown to regulate inflammation and ECM proteins in different diseases. Nimbidiol is a neem-derived diterpenoid that is considered as a potential anti-diabetic compound due to its glucosidase inhibitory properties. We investigated whether Nimbidiol mitigates adverse ECM accumulation and renal fibrosis to improve kidney function in type-1 diabetes and the underlying mechanism. Wild-type (C57BL/6J) and type-1 diabetic (C57BL/6-Ins2^Akita/J) mice were treated either with saline or with Nimbidiol (0.40 mg kg^-1 d^-1) for eight weeks. Diabetic kidney showed increased accumulation of M1 macrophages, elevated pro-inflammatory cytokines and EMT. In addition, upregulated MMP-9 and MMP-13, excessive collagen deposition in the glomerular and tubulointerstitial regions, and degradation of vascular elastin resulted to renal fibrosis in the Akita mice. These pathological changes in the diabetic mice were associated with functional impairments that include elevated resistive index and reduced blood flow in the renal cortex, and decreased glomerular filtration rate. Furthermore, TGF-β1, p-Smad2/3, p-P38, p-ERK1/2 and p-JNK were upregulated in diabetic kidney compared to WT mice. Treatment with Nimbidiol reversed the changes to alleviate inflammation, ECM accumulation and fibrosis and thus, improved renal function in Akita mice. Together, our results suggest that Nimbidiol attenuates inflammation and ECM accumulation and thereby, protects kidney from fibrosis and dysfunction possibly by inhibiting TGF-β/Smad and MAPK signaling pathways in type-1 diabetes.

Kirenol alleviates diabetic nephropathy via regulating TGF-β/Smads and the NF-κB signal pathway

CONTEXT

Kirenol possesses anti-inflammatory, antifibrotic and anti-arthritic effects. However, its reno-protective effects against diabetic nephropathy (DN) have not been evaluated.

OBJECTIVE

This study explores the reno-protective effects of kirenol against DN and clarifies the potential mechanisms.

MATERIALS AND METHODS

The mesangial cells were treated with 20 µM kirenol and 10 ng/mL human recombinant TGF-β1 or 30 mM glucose for 24 h. Then the cells were harvested to assay the expression of the target genes or proteins. Thirty C57BL/6J male mice were given high-fat diet with streptozotocin injection to induce diabetes and then were randomized into three groups (n = 10): vehicle administration (DM group), 2 mg/kg kirenol (DM + kirenol group) and 200 mg/kg metformin (Met group) for 3 months, orally. A healthy group (Con, n = 10) was included as the control.

RESULTS

Compared to the DM group, kirenol treatment decreased the phosphorylation of Smad2/3 and NF-κB (0.64- and 0.43-fold) as well as the accumulation of FN and Col IV (0.58- and 0.35-fold); moreover, the expression of IκBα was restored to normal level by kirenol treatment both in vivo and in vitro. After kirenol treatment, IL-6 expression was decreased 0.35- and 0.57-fold, and TNF-α expression was decreased 0.34- and 0.46-fold, in vitro and in vivo, respectively. Furthermore, kirenol alleviated the glomerular basement membrane thickness and foot process fusion.

DISCUSSION AND CONCLUSIONS

Kirenol could alleviate DN by downregulating the TGF-β/Smads and the NF-κB signal pathway. Our study provides a potential mechanism for the treatment of DN with kirenol.

The improvement of Coreopsis tinctoria essential oil on learning and memory impairment of d-galactose-induced mice through Nrf2/NF-κB pathway

Essential oil of Coreopsis tinctoria (EOC) is a essential substance extracted from Coreopsis tinctoria with the excellent anti-oxidant effect. However, it is still unclear whether EOC can improve learning and memory impairment and its mechanism. The purpose of this study was to investigate the effect of EOC on learning and memory impairment induced by D-galactose (D-gal) in mice and reveal its mechanism. The composition of EOC was analyzed by GC-MS, and the results showed that the highest content was D-limonene. The follow-up experiments were conducted by comparing EOC with D-limonene. The aging model was established by subcutaneous injection of D-gal, and donepezil, D-limonene and EOC were given by intragastric administration. It was found that EOC and D-limonene significantly improved learning and memory impairment induced by D-gal through the Morris water maze and step-through tests. Pathological and biochemical analysis showed that the hippocampal morphologic of mice was damage and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) induced by D-gal were decreased, while the content of malondialdehyde (MDA) was increased, while EOC and D-limonene could reverse the morphological changes and reduce oxidative damage. In addition, EOC and D-limonene significantly increased body weight and organ coefficients, including liver, spleen and kidney. Moreover, EOC and D-limonene improved the expression of nuclear factor E2 related factor 2 (Nrf2) pathway and inhibited nuclear transcription factors-κB (NF-κB) pathway. In summary, the results showed that EOC and D-limonene could improve learning and memory impairment induced by D-gal through Nrf2/ NF-κB pathway. It was clear that as a mixture, EOC was better than D-limonene on improving learning and memory impairment.

Sestrin2 attenuates renal damage by regulating Hippo pathway in diabetic nephropathy

Glomerular mesangial cell proliferation and extracellular matrix accumulation contribute to the progression of diabetic nephropathy (DN). As a conserved stress-inducible protein, sestrin2 (Sesn2) plays critical role in the regulation of oxidative stress, inflammation, autophagy, metabolism, and endoplasmic reticulum stress. In this study, we investigated the role of Sesn2 on renal damage in diabetic kidney using transgenic mice overexpressing Sesn2 and the effect of Sesn2 on mesangial cell proliferation and extracellular matrix accumulation in diabetic conditions and the possible molecular mechanisms involved. Sesn2 overexpression improved renal function and decreased glomerular hypertrophy, albuminuria, mesangial expansion, extracellular matrix accumulation, and TGF-β1 expression, as well as oxidative stress in diabetic mice. In vitro experiments, using human mesangial cells (HMCs), revealed that Sesn2 overexpression inhibited high glucose (HG)-induced proliferation, fibronectin and collagen IV production, and ROS generation. Meanwhile, Sesn2 overexpression restored phosphorylation levels of Lats1 and YAP and inhibited TEAD1 expression. Inhibition of Lats1 accelerated HG-induced proliferation and expression of fibronectin and collagen IV. Verteporfin, an inhibitor of YAP, suppressed HG-induced proliferation and expression of fibronectin and collagen IV. However, Sesn2 overexpression reversed Lats1 deficiency-induced Lats1 and YAP phosphorylation, nuclear expression levels of YAP and TEAD1, and proliferation and fibronectin and collagen IV expressions in HMCs exposed to HG. In addition, antioxidant NAC or tempol treatment promoted phosphorylation of Lats1 and YAP and inhibited TEAD1 expression, proliferation, and fibronectin and collagen IV accumulation in HG-treated HMCs. Taken together, Sesn2 overexpression inhibited mesangial cell proliferation and fibrosis via regulating Hippo pathway in diabetic nephropathy. Induction of Sesn2 may be a potential therapeutic target in diabetic nephropathy.

N-type calcium channel and renal injury

Accumulating evidences indicated that voltage-gated calcium channels (VDCC), including L-, T-, N-, and P/Q-type, are present in kidney and contribute to renal injury during various chronic diseases trough different mechanisms. As a voltage-gated calcium channel, N-type calcium channel was firstly been founded predominately distributed on nerve endings which control neurotransmitter releases. Since sympathetic nerve is distributed along renal afferent and efferent arterioles, N-type calcium channel blockade on sympathetic nerve terminals would bring renal dynamic improvement by dilating both arterioles and reducing glomerular pressure. In addition, large body of scientific research indicated that neurotransmitters, such as norepinephrine, releases by activating N-type calcium channel can trigger inflammatory and fibrotic signaling pathways in kidney. Interestingly, we recently demonstrated that N-type calcium channel is also expressed on podocytes and may directly contribute to podocyte injury in denervated animal models. In this paper, we will summarize our current knowledge regarding renal N-type calcium channels, and discuss how they might contribute to the river that terminates in renal injury.

Hypoglycemic bioactivity of anthocyanins: A review on proposed targets and potential signaling pathways

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with complicated interrelationships responsible for initiating its pathogenesis. Novel strategies for the treatment of this devastating disease have attracted increasing attention worldwide. Anthocyanins are bioactive compounds that are widely distributed in the plant kingdom, and multiple studies have elucidated their beneficial role in preventing and managing T2DM. This review summarizes and comments on the hypoglycemic actions of anthocyanins from the perspective of molecular mechanisms and different target-related signaling pathways in vitro, in vivo, and clinical trials. Anthocyanins can ameliorate T2DM by functioning as carbohydrate digestive enzyme inhibitors, facilitating glucose transporter 4 (GLUT4) translocation, suppressing the effectiveness of dipeptidyl peptidase IV (DPP-IV), promoting glucagon-like peptide-1 (GLP-1) secretion, inhibiting protein tyrosine phosphatase 1B (PTP1B) overexpression, and interacting with sodium-glucose co-transporter (SGLT) to delay glucose absorption in various organs and tissues. In summary, anthocyanin is a promising and practical small molecule that can hyperglycemic symptoms and accompanying complications suffered by patients with diabetes. However, rational and potent doses for daily intake and clinical studies are required in the future.

Therapeutic role of Azadirachta indica leaves ethanolic extract against diabetic nephropathy in rats neonatally induced by streptozotocin

Diabetic nephropathy (DN) is manifested by chronic loss of renal function due to damage of glomeruli and renal tubules. Therefore, this study is mainly designed to evaluate the therapeutic role of Azadiracta indica (neem) leaves extract as a novel approach for treatment of DN in rats neonatally induced by streptozotocin (STZ). For this study, 40 offspring were selected after parturition and categorized into four groups (n = 10). Group1: control group, group 2: neem leaves extract supplemented group, group 3: diabetic group that injected with a single dose of STZ and group 4: diabetic group treated with neem extract. The results revealed deleterious histological and ultrstructural changes in the renal tissues of diabetic rats. Such changes included atrophied glomeruli, dilated renal cortical tubules and scattered hemorrhage spots, thickening of glomerular basement membrane, expansion of mesangial matrix and pyknotic podocyte. Additionally, the proximal convoluted tubule and distal tubule showed cytoplasmic vacuolation, vacuolated mitochondria, scattered lipid droplets, lost microvilli and disrupted basal lamina and basal infoldings. Moreover, significant decreased levels of serum antioxidants (SOD&CAT) and significant increased levels of serum MDA, urea and creatinine were noticed in diabetic rats. Neem leaves extract successfully alleviated the histological and ultrastructural as well as biochemical changes induced by diabetes.

GYY4137 Regulates Extracellular Matrix Turnover in the Diabetic Kidney by Modulating Retinoid X Receptor Signaling

Diabetic kidney is associated with an accumulation of extracellular matrix (ECM) leading to renal fibrosis. Dysregulation of retinoic acid metabolism involving retinoic acid receptors (RARs) and retinoid X receptors (RXRs) has been shown to play a crucial role in diabetic nephropathy (DN). Furthermore, RARs and peroxisome proliferator-activated receptor γ (PPARγ) are known to control the RXR-mediated transcriptional regulation of several target genes involved in DN. Recently, RAR and RXR have been shown to upregulate plasminogen activator inhibitor-1 (PAI-1), a major player involved in ECM accumulation and renal fibrosis during DN. Interestingly, hydrogen sulfide (H₂S) has been shown to ameliorate adverse renal remodeling in DN. We investigated the role of RXR signaling in the ECM turnover in diabetic kidney, and whether H₂S can mitigate ECM accumulation by modulating PPAR/RAR-mediated RXR signaling. We used wild-type (C57BL/6J), diabetic (C57BL/6-Ins2^Akita/J) mice and mouse mesangial cells (MCs) as experimental models. GYY4137 was used as a H₂S donor. Results showed that in diabetic kidney, the expression of PPARγ was decreased, whereas upregulations of RXRα, RXRβ, and RARγ1 expression were observed. The changes were associated with elevated PAI-1, MMP-9 and MMP-13. In addition, the expressions of collagen IV, fibronectin and laminin were increased, whereas elastin expression was decreased in the diabetic kidney. Excessive collagen deposition was observed predominantly in the peri-glomerular and glomerular regions of the diabetic kidney. Immunohistochemical localization revealed elevated expression of fibronectin and laminin in the glomeruli of the diabetic kidney. GYY4137 reversed the pathological changes. Similar results were observed in in vitro experiments. In conclusion, our data suggest that RXR signaling plays a significant role in ECM turnover, and GYY4137 modulates PPAR/RAR-mediated RXR signaling to ameliorate PAI-1-dependent adverse ECM turnover in DN.

Ginkgetin alleviates high glucose-evoked mesangial cell oxidative stress injury, inflammation, and extracellular matrix (ECM) deposition in an AMPK/mTOR-mediated autophagy axis

Diabetic nephropathy constitutes the leading cause for end-stage kidney disease. Ginkgetin is a common natural non-toxic biflavone and fulfills pleiotropic pharmacological characterizations, such as anti-inflammation and kidney injury. Nevertheless, its efficacy in diabetic nephropathy remains elusive. Here, ginkgetin exhibited little cytotoxicity in glomerular mesangial cells. Of note, ginkgetin restrained high glucose (HG)-induced mesangial cell proliferation and oxidative stress by inhibiting ROS and malonaldehyde levels, but enhancing antioxidant SOD activity. Additionally, ginkgetin suppressed HG-evoked transcript and release of inflammatory cytokine TNF-α, IL-1β, and IL-6. Concomitantly, the increased extracellular matrix (ECM) deposition in HG-treated glomerular mesangial cells was attenuated by ginkgetin via decreasing expression of collagen IV, fibronectin, and laminin. Intriguingly, ginkgetin-restored HG-impaired autophagy; whereas blocking autophagy by its inhibitor 3-MA overturned ginkgetin function against HG-evoked mesangial cell dysfunction. Mechanistically, ginkgetin-mediated AMPK/mTOR axis accounted for HG-impaired autophagy. Importantly, blockage of AMPK signaling reversed ginkgetin-restored autophagy and its protective efficacy against HG-induced dysfunction in mesangial cells. Thus, these findings highlight that ginkgetin may attenuate HG-evoked mesangial cell hyperplasia, oxidative stress, inflammation, and ECM accumulation by activating AMPk/mTOR-mediated autophagy pathway. Therefore, ginkgetin may alleviate the progression of diabetic nephropathy by regulating glomerular mesangial cell dysfunction, supporting a promising therapeutic agent against diabetic nephropathy.

An updated pharmacological insight of resveratrol in the treatment of diabetic nephropathy

As one of the most common complications of diabetes, nephropathy develops in approximately 40% of diabetic individuals. Although end stage kidney disease is known as one of the most consequences of diabetic nephropathy, the majority of diabetic individuals might die from cardiovascular diseases and infections before renal replacement treatment. Moreover, the routine medical treatments for diabetes hold undesirable side effects. The explosive prevalence of diabetes urges clinicians and scientists to investigate the complementary or alternative therapies. Phytochemicals are emerging as alternatives with a wide range of therapeutic effects on various pathologies, including diabetic kidney disease. Of those phytochemicals, resveratrol, a natural polyphenolic stilbene, has been found to exert a broad spectrum of health benefits via various signaling molecules. In particular, resveratrol has gained a great deal of attention because of its anti-oxidative, anti-inflammatory, anti-diabetic, anti-obesity, cardiovascular-protective, and anti-tumor properties. In the renal system, emerging evidence shows that resveratrol has already been used to ameliorate chronic or acute kidney injury. This review critically summarizes the current findings and molecular mechanisms of resveratrol in diabetic renal damage. In addition, we will discuss the adverse and inconsistent effects of resveratrol in diabetic nephropathy. Although there is increasing evidence that resveratrol affords great potential in diabetic nephropathy therapy, these results should be treated with caution before its clinical translation. In addition, the unfavorable pharmacokinetics and/or pharmacodynamics profiles, such as poor bioavailability, may limit its extensive clinical applications. It is clear that further research is needed to unravel these limitations and improve its efficacy against diabetic nephropathy. Increasing investigation of resveratrol in diabetic kidney disease will not only help us better understand its pharmacological actions, but also provide novel potential targets for therapeutic intervention.

A 75 kDa glycoprotein isolated from Cudrania tricuspidata Bureau induces colonic epithelial proliferation and ameliorates mouse colitis induced by dextran sulfate sodium

Cudrania tricuspidata Bureau (CTB), a species of the Moraceae plant, has been used as a bruise recovery treatment. This study aimed to determine whether the 75 kDa phytoglycoprotein extracted from CTB has a regulatory effect on the proliferation of human colon epithelial cells and the pathological process of inflammatory bowel disease (IBD). We found that CTB glycoprotein significantly induces the proliferation of human colon epithelial HT-29 cells by activating protein kinase C. CTB glycoprotein stimulated the phosphorylation of c-Jun N-terminal kinase and transcription factor nuclear factor-κB, which are responsible for the expression of cell-cycle-related proteins (CDK2, CDK4, cyclin D1 and cyclin E) during its promotion of cell proliferation. Experimental colitis was induced in mice by adding dextran sulfate sodium to their drinking water at a concentration of 4% (W/V) for seven days. We found that CTB glycoprotein ameliorates the pathological process of IBD and lowers the disease activity index score, which was composed of body weight change, diarrhea, and hematochezia in ICR mice treated with dextran sulfate sodium. Hence, we suggest that CTB glycoprotein has the ability to prevent IBD by promoting cell proliferation signaling events via the activation of PKC, JNK and NF-κB in colon epithelial cells.

Therapeutic application of nutraceuticals in diabetic nephropathy: Current evidence and future implications

Diabetes mellitus (DM) is a common metabolic disease which may cause several complications, such as diabetic nephropathy (DN). The routine medical treatments used for DM are not effective enough and have many undesirable side effects. Moreover, the global increased prevalence of DM makes researchers try to explore potential complementary or alternative treatments. Nutraceuticals, as natural products with pharmaceutical agents, have a wide range of therapeutic properties in various pathologic conditions such as DN. However, the exact underlying mechanisms have not been fully understood. The purpose of this review is to summarize recent findings on the effect of nutraceuticals on DN.

Discovery of a dual inhibitor of NQO1 and GSTP1 for treating glioblastoma

BACKGROUND

Glioblastoma (GBM) is a universally lethal tumor with frequently overexpressed or mutated epidermal growth factor receptor (EGFR). NADPH quinone oxidoreductase 1 (NQO1) and glutathione-S-transferase Pi 1 (GSTP1) are commonly upregulated in GBM. NQO1 and GSTP1 decrease the formation of reactive oxygen species (ROS), which mediates the oxidative stress and promotes GBM cell proliferation.

METHODS

High-throughput screen was used for agents selectively active against GBM cells with EGFRvIII mutations. Co-crystal structures were revealed molecular details of target recognition. Pharmacological and gene knockdown/overexpression approaches were used to investigate the oxidative stress in vitro and in vivo.

RESULTS

We identified a small molecular inhibitor, "MNPC," that binds to both NQO1 and GSTP1 with high affinity and selectivity. MNPC inhibits NQO1 and GSTP1 enzymes and induces apoptosis in GBM, specifically inhibiting the growth of cell lines and primary GBM bearing the EGFRvIII mutation. Co-crystal structures between MNPC and NQO1, and molecular docking of MNPC with GSTP1 reveal that it binds the active sites and acts as a potent dual inhibitor. Inactivation of both NQO1 and GSTP1 with siRNA or MNPC results in imbalanced redox homeostasis, leading to apoptosis and mitigated cancer proliferation in vitro and in vivo.

CONCLUSIONS

Thus, MNPC, a dual inhibitor for both NQO1 and GSTP1, provides a novel lead compound for treating GBM via the exploitation of specific vulnerabilities created by mutant EGFR.

Resveratrol: Evidence for Its Nephroprotective Effect in Diabetic Nephropathy

Diabetic nephropathy (DN) is a severe complication of diabetes mellitus (DM). Dietary habits play a major role in determining the onset and progression of DM-related disorders and a proper diet (rich in fruits and vegetables) can delay or prevent the process of DM pathogenesis. Thus, increasing attention has been paid to polyphenols and polyphenol-rich foods since their increased intake has been associated with a reduced incidence of DM and its associated complications. Resveratrol is a polyphenolic phytoalexin that is mainly found in grapevines and berries. It is available in various pharmaceutical dosages and is widely recommended as a dietary supplement due to its beneficial effects. Remarkably, resveratrol's capability to effectively lower blood glucose levels without any side effects has been amply demonstrated in many in vitro and in vivo studies. Herein, we comprehensively review and discuss the nephroprotective effect of resveratrol during DN and its associated mechanisms. Resveratrol exerts its nephroprotective effects via various mechanisms including reducing oxidative stress and advanced glycation end-product (AGE) production, stimulating autophagy, inhibiting endoplasmic reticulum (ER) stress and inflammation, ameliorating lipotoxicity, activating the AMP kinase (AMPK) pathway, and modulating angiogenesis. Moreover, the use of resveratrol as an adjuvant to conventional antidiabetic therapies could be an effective approach to manage DN in humans. However, evidence is scarce to support whether resveratrol has beneficial effects in humans during DN. Therefore, clinical studies are warranted to elucidate resveratrol's role against DN.

miR-181a-5p regulates the proliferation and apoptosis of glomerular mesangial cells by targeting KLF6

Diabetic nephropathy (DN) is a chronic loss of kidney function that frequently occurs in patients with diabetes mellitus and is characterized by abnormal glomerular mesangial cell (GMC) proliferation and apoptosis. By using microarray analysis, microRNA (miR)-181a-5p has previously been identified to be dysregulated in DN. The present study aimed to determine the underlying molecular mechanisms and function of miR-181a-5p in GMCs under DN conditions. First, reverse transcription-quantitative PCR was performed to detect miR-181a-5p and kruppel-like factor 6 (KLF6) expression in GMCs following high-glucose treatment. Subsequently, MTT and flow cytometric assays were performed in order to determine the effect of miR-181a-5p and KLF6 on high-glucose-driven GMC proliferation and apoptosis. After confirming that KLF6 was a target gene of miR-181a-5p via a bioinformatics analysis and luciferase reporter assay, the mRNA and protein expression levels of associated factors in different treatment groups were measured. The results demonstrated that miR-181a-5p was significantly downregulated, while KLF6 was significantly upregulated in GMCs following treatment with high glucose. Furthermore, overexpression of miR-181a led to suppression of cell proliferation and promoted apoptosis of GMCs induced by high glucose, while these effects were inhibited by co-transfection with KLF6. Finally, miR-181-5p was demonstrated to inhibit the expression of KLF6, Bcl-2, Wnt1 and β-catenin, while increasing the expression levels of Bax and caspase-3. In conclusion, the expression levels of miR-181a-5p were downregulated in GMCs following treatment with high glucose and overexpression of miR-181a-5p may inhibit GMC proliferation and promote apoptosis, at least partially through targeting KLF6 via the Wnt/β-catenin signaling pathway. Overall, the results of the present study suggest that miR-181a-5p may have a crucial role in the occurrence and development of DN and may be a valuable diagnostic marker and therapeutic target for DN.

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^-1· d^-1, ig) or a positive control drug resveratrol (40 mg· kg^-1· d^-1, 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.

A review on the potential of Resveratrol in prevention and therapy of diabetes and diabetic complications

Diabetes mellitus (DM) is a major world health problem and one of the most studied diseases, which are highly prevalent in the whole world, it is frequently associated with severe clinical complications, such as diabetic cardiomyopathy, nephropathy, retinopathy, neuropathy etc. Scientific research is continuously casting about for new monomer molecules from Chinese herbal medicine that could be invoked as candidate drugs for fighting against diabetes and its complications. Resveratrol (RES), a polyphenol phytoalexin, possesses diverse biochemical and physiological actions, including antiplatelet, estrogenic, and anti-inflammatory properties. It is recently gaining scientific interest for RES in controlling blood sugar and fighting against diabetes and its complications properties in various types of diabetic models. These beneficial effects seem to be due to the multiple actions of RES on cellular functions, which make RES become a promising molecule for the treatment of diabetes and diabetic complications. Here, we review the mechanism of action and potential therapeutic use of RES in prevention and mitigation of these diseases in recent ten years to provide a reference for further research and development of RES.

Resveratrol Inhibits Lipopolysaccharide-Induced Extracellular Matrix Accumulation and Inflammation in Rat Glomerular Mesangial Cells by SphK1/S1P2/NF-κB Pathway

PURPOSE

Chronic inflammation plays a key role in the pathogenesis of various diseases such as diabetic nephropathy (DN). Resveratrol (RSV), a natural polyphenol, has been proven to have renoprotective effects. In this study, we used a lipopolysaccharide (LPS)-induced rat glomerular mesangial cells (RMCs) model, to elucidate the renoprotective effect of RSV on sphingosine kinase 1 (SphK1)/sphingosine 1-phosphate receptor 2 (S1P2)/NF-κB activation and the expression of downstream inflammatory mediators, such as intercellular adhesion molecule-1 (ICAM-1), inducible nitric oxide synthase (iNOS) and fibronectin (FN) protein expression in RMCs.

METHODS

Cell proliferation was tested by 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide (MTT). The protein levels of FN, ICAM-1, iNOS, SphK1, S1P2 and NF-κB p65 in RMCs were detected by Western blot. The DNA-binding activity of NF-κB was detected by electrophoretic mobility shift assay (EMSA). SphK1 activity and S1P content were measured by using sphingosine kinase activity assay kit and ELISA assay, respectively.

RESULTS

We first found that LPS could stimulate SphK1/S1P axis activation, whereas this occurrence was significantly blocked by RSV pretreatment. RSV obviously repressed LPS-induced upregulated expression of fibronectin (FN), intercellular adhesion molecule-1 (ICAM-1) and inducible nitric oxide synthase (iNOS) in RMCs. Moreover, RSV markedly reduced SphK1 activity and its protein expression, and attenuated S1P content in LPS-induced RMCs. Furthermore, RSV could block LPS-induced upregulation of NF-κB p65 and DNA-binding activity of NF-κB. And this phenomenon was notably attenuated by SphK1 inhibitor and S1P2 inhibitor.

CONCLUSION

RSV inhibited LPS-induced RMCs' proliferation and inflammation and FN expression by SphK1/S1P2/NF-κB pathway, suggesting that RSV may be independent of its hypoglycemic effect on preventing or delaying the development of mesangial cell fibrosis.

Ethyl Vanillin Protects against Kidney Injury in Diabetic Nephropathy by Inhibiting Oxidative Stress and Apoptosis

Diabetes-induced oxidative stress and apoptosis is regarded as a critical role in the pathogenesis of diabetic nephropathy (DN). Treating diabetes-induced kidney damage and renal dysfunction has been thought a promising therapeutic option to attenuate the development and progression of DN. In this study, we investigated the renoprotective effect of ethyl vanillin (EVA), an active analogue of vanillin isolated from vanilla beans, on streptozotocin- (STZ-) induced rat renal injury model and high glucose-induced NRK-52E cell model. The EVA treatment could strongly improve the deterioration of renal function and kidney cell apoptosis in vivo and in vitro. Moreover, treating with EVA significantly decreased the level of MDA and reactive oxygen species (ROS) and stabilized antioxidant enzyme system in response to oxidative stress by enhancing the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in vivo and in vitro. Furthermore, EVA also markedly suppressed cleaved caspase-3, Bax, and nuclear transcription factor erythroid 2-related factor (Nrf2) expression in STZ-induced rats. Therefore, these results of our investigation provided that EVA might protect against kidney injury in DN by inhibiting oxidative stress and cell apoptosis.

BDNF (Brain-Derived Neurotrophic Factor) Promotes Embryonic Stem Cells Differentiation to Endothelial Cells Via a Molecular Pathway, Including MicroRNA-214, EZH2 (Enhancer of Zeste Homolog 2), and eNOS (Endothelial Nitric Oxide Synthase)

Objective- The NTs (neurotrophins), BDNF (brain-derived neurotrophic factor) and NT-3 promote vascular development and angiogenesis. This study investigated the contribution of endogenous NTs in embryonic stem cell (ESC) vascular differentiation and the potential of exogenous BDNF to improve the process of ESC differentiation to endothelial cells (ECs). Approach and Results- Mouse ESCs were differentiated into vascular cells using a 2-dimensional embryoid body (EB) model. Supplementation of either BDNF or NT-3 increased EC progenitors' abundance at day 7 and enlarged the peripheral vascular plexus with ECs and SM22α⁺ (smooth muscle 22 alpha-positive) smooth muscle cells by day 13. Conversely, inhibition of either BDNF or NT-3 receptor signaling reduced ECs, without affecting smooth muscle cells spread. This suggests that during vascular development, endogenous NTs are especially relevant for endothelial differentiation. At mechanistic level, we have identified that BDNF-driven ESC-endothelial differentiation is mediated by a pathway encompassing the transcriptional repressor EZH2 (enhancer of zeste homolog 2), microRNA-214 (miR-214), and eNOS (endothelial nitric oxide synthase). It was known that eNOS, which is needed for endothelial differentiation, can be transcriptionally repressed by EZH2. In turn, miR-214 targets EZH2 for inhibition. We newly found that in ESC-ECs, BDNF increases miR-214 expression, reduces EZH2 occupancy of the eNOS promoter, and increases eNOS expression. Moreover, we found that NRP-1 (neuropilin 1), KDR (kinase insert domain receptor), and pCas¹³⁰ (p130 Crk-associated substrate kinase), which reportedly induce definitive endothelial differentiation of pluripotent cells, were increased in BDNF-conditioned ESC-EC. Mechanistically, miR-214 mediated the BDNF-induced expressional changes, contributing to BDNF-driven endothelial differentiation. Finally, BDNF-conditioned ESC-ECs promoted angiogenesis in vitro and in vivo. Conclusions- BDNF promotes ESC-endothelial differentiation acting via miR-214.

Health Benefits of Resveratrol in Kidney Disease: Evidence from In Vitro and In Vivo Studies

Different diseases and disorders that affect the kidneys include, but are not limited to, glomerulonephritis, diabetic nephropathy, polycystic kidney disease, kidney stones, renal fibrosis, sepsis, and renal cell carcinoma. Kidney disease tends to develop over many years, making it difficult to identify until much later when kidney function is severely impaired and undergoing kidney failure. Although conservative care, symptom management, medication, dialysis, transplantation, and aggressive renal cancer therapy are some of the current strategies/approaches to kidney disease treatment, new preventative targeted therapies are needed. Epidemiological studies have suggested that a diet rich in fruits and vegetables is associated with health benefits including protection against kidney disease and renal cancer. Resveratrol, a polyphenol found in grapes and berries, has been reported to have antioxidant, anti-inflammatory, antidiabetic, hepatoprotective, neuroprotective, and anti-cancer properties. The current review summarizes the existing in vitro and in vivo animal and human studies examining the nephroprotective effects of resveratrol.

Excessive apoptosis of podocytes caused by dysregulation of microRNA-182-5p and CD2AP confers to an increased risk of diabetic nephropathy

The functions of miR-182-5p in the pathogenesis of diabetic nephropathy (DN) remain largely unclear. Here, we studied the roles and relationship between miR-182-5p and CD2AP in the development of DN. We used real-time polymerase chain reaction (PCR) to compare miR-182-5p expression between DN and control groups, while computational analysis and luciferase assays were used to confirm CD2AP as a miR-182-5p target. Western blot and real-time PCR were then used to measure the messenger RNA (mRNA) and protein expression of CD2AP in the presence of miR-182-5p. The results showed that miR-182-5p was highly expressed in cells isolated from people with DN. In addition, the luciferase activity of cells transfected with wild-type/mutant CD2AP confirmed CD2AP as a direct target of miR-182-5p. The expression levels of CD2AP mRNA and protein were much lower in the DN group compared with that in the normal group. In addition, the expression levels of CD2AP mRNA and protein were evidently increased by a miR-182-5p inhibitor, but notably downregulated by miR-182-5p mimics or CD2AP small interfering RNA (siRNA). Furthermore, miR-182-5p and CD2Ap siRNA significantly reduced the survival rate and viability of transfected cells, while the miR-182-5p inhibitor exhibited an opposite effect. These findings indicated the presence of a negative regulatory relationship between miR-182-5p and CD2AP in podocytes cells and suggested that the overexpression of miR-182-5p contributes to the pathogenesis of DN.

Concomitant administration of resveratrol and insulin protects against diabetes mellitus type-1-induced renal damage and impaired function via an antioxidant-mediated mechanism and up-regulation of Na+/K+-ATPase

This study investigated if a combination of resveratrol (RES) and insulin could reverse type 1 diabetic mellitus-induced (T1DM) nephropathy and illustrates mechanism of action. Rats were divided into six groups (n = 10/group) as follows: control, control + RES (20 mg/kg), T1DM, T1DM + RES, T1DM + insulin (1 U/g), and T1DM + RES + insulin and treated for eight weeks. While individual administrations of both drugs significantly but partially restored renal function and cortex architectures, combination therapy of both RES and insulin produced the maximum improvements. Mechanism of actions revealed a synergist effect of both drugs due to hypoglycaemic effect of insulin and the ability of both drugs to increase renal cortex antioxidant enzymes activities, inhibit lipid peroxidation, and up-regulate Na⁺/K⁺-ATPase, independent of each others. In conclusion, these data suggest the combined therapy with insulin and RES could provide an excellent combined drug therapy against T1DM-induced nephropathy.

Glucose fluctuation increased mesangial cell apoptosis related to AKT signal pathway

INTRODUCTION

Blood glucose fluctuation is an important factor for the development of diabetic complications. Glucose fluctuation aggravated the renal injury in diabetic nephropathy. In the present study, our aim was to investigate the effects of blood glucose fluctuation on the glomerular mesangal cells and its related mechanism.

MATERIAL AND METHODS

Mesangial cells were divided into four groups: the normal glucose group (NG) cells were incubated in normal glucose conditions (5.6 mmol/l); the high glucose group (HG) cells were treated with 25 mmol/l; the glucose fluctuation (FG) group received 5.6 mmol/l and 25 mmol/l glucose repeated 3 times; the mannitol group (MG) received 5.6 mmol/l glucose plus 24.4 mmol/l mannitol as a control. Cell viability and apoptosis were detected, reactive oxygen species (ROS) level, superoxide dismutase (SOD) activity and malonaldehyde (MDA) levels were measured. Phosphorylated ser/thr protein kinase (P-AKT, phosphor-Ser473), phosphorylated glycogen synthase kinase-3β (P-GSK-3β, phosphor-Ser9) and cleaved cysteinyl aspartate-specific proteinase-3 (cleaved caspase-3) levels were assessed using western blot.

RESULTS

Data suggested that mesangial cells in the FG group show higher cell viability in 12 h, and lower cell viability from 48 h. The FG group showed cell apoptosis accompanied by a significant MDA level increase and SOD activity decrease in 48 h. More importantly, glucose fluctuation could aggravate oxidative stress in glomerular mesangial cells. Furthermore, the P-AKT level was lower, and increased P-GSK-3β and cleaved caspase-3 levels were higher in the FG group than in the HG group.

CONCLUSIONS

Glucose fluctuation aggravates mesangial cell apoptosis, which may be partly induced by activating oxidative stress and inhibiting the AKT signaling pathway.

Perilla frutescens Sprout Extract Protect Renal Mesangial Cell Dysfunction against High Glucose by Modulating AMPK and NADPH Oxidase Signaling

Perilla frutescens (L.) Britt. var. japonica (Hassk.) Hara (PF), is a medical herb of the Lamiaceae family. We have previously reported that the PF sprout extract (PFSE) is effective in treating hyperglycemia. However, the role of PFSE on glomerular mesangial cells (MCs) proliferation and the extracellular matrix (ECM) accumulation in a diabetic condition are still unclear. Therefore, in this study, we have investigated the role of PFSE on cell proliferation and ECM accumulation in murine glomerular MCs (MMCs), cultured under a high glucose (HG) condition. PFSE treatment attenuated HG-induced MMCs proliferation and hypertrophy. Moreover, the HG-induced ECM protein, collagen IV and fibronectin, overexpression was abolished by the PFFSE treatment. In addition, PFSE inhibited reactive oxygen species (ROS) overproduction and NOX2 and NOX4 expression in MMCs under a HG condition. Our data further revealed the involvement of mesangial cell damage in AMP-activated kinase (AMPK) activation. PFSE strongly activated AMPK in MMCs under hyperglycemic conditions. These results suggest that PFSE inhibits HG-medicated MC fibrosis through suppressing the activation of NOX2/4 and the AMPK activation mechanism. PFSE may be useful for the prevention or treatment of diabetic nephropathy.

Acute glucose fluctuation impacts microglial activity, leading to inflammatory activation or self-degradation

Diabetes mellitus is associated with an increased risk of Alzheimer’s dementia and cognitive decline. The cause of neurodegeneration in chronic diabetic patients remains unclear. Changes in brain microglial activity due to glycemic fluctuations may be an etiological factor. Here, we examined the impact of acute ambient glucose fluctuations on BV-2 microglial activity. Biochemical parameters were assayed and showed that the shift from normal glucose (NG; 5.5 mM) to high glucose (HG; 25 mM) promoted cell growth and induced oxidative/inflammatory stress and microglial activation, as evidenced by increased MTT reduction, elevated pro-inflammatory factor secretion (i.e., TNF-α and oxygen free radicals), and upregulated expression of stress/inflammatory proteins (i.e., HSP70, HO-1, iNOS, and COX-2). Also, LPS-induced inflammation was enlarged by an NG-to-HG shift. In contrast, the HG-to-NG shift trapped microglia in a state of metabolic stress, which led to apoptosis and autophagy, as evidenced by decreased Bcl-2 and increased cleaved caspase-3, TUNEL staining, and LC3B-II expression. These stress episodes were primarily mediated through MAPKs, PI3K/Akt, and NF-κB cascades. Our study demonstrates that acute glucose fluctuation forms the stress that alters microglial activity (e.g., inflammatory activation or self-degradation), representing a novel pathogenic mechanism for the continued deterioration of neurological function in diabetic patients.

Mesangial Cells and Renal Fibrosis

The main cellular constituents in glomerular mesangium are mesangial cells, which account for approximately 30-40% of the total cells in the glomerulus. Together with the mesangial matrix, mesangial cells form the glomerular basement membrane (GBM) in the glomerulus, whose main function is to perform the filtration. Under the pathologic conditions, mesangial cells are activated, leading to hyperproliferation and excess extracellular matrix (ECM). Moreover, mesangial cells also secrete several kinds of inflammatory cytokines, adhesion molecules, chemokines, and enzymes, all of which participate in the process of renal glomerular fibrosis. During the past years, researchers have revealed the roles of mesangial cells and the associated signal pathways involved in renal fibrosis. In this section, we will discuss how mesangial cells are activated and its contributions to renal fibrosis, as well as the molecular mechanisms and novel anti-fibrotic agents. Full understanding of the contributions of mesangial cells to renal fibrosis will benefit the clinical drug developing.

Resveratrol exerts dose-dependent anti-fibrotic or pro-fibrotic effects in kidneys: A potential risk to individuals with impaired kidney function

BACKGROUND

Renal fibrosis is the pathological feature of chronic kidney disease (CKD) which leads to end-stage renal disease (ESRD) and renal failure. Resveratrol [3,5,4'-trihydroxy-trans-stilbene (RSV)] has shown benefits for metabolic diseases and anti-cancer therapy, but its potential risk on renal health has not been fully evaluated.

PURPOSE

To investigate the global effects of RSV on renal fibrosis in human tubular epithelial cell (TEC) line HK-2, and in mice with unilateral ureteral obstruction (UUO).

METHODS

A TGF-β-induced in vitro model of epithelial-mesenchymal transition (EMT) in TEC was established. The effects of RSV on cell viability, pro-fibrotic factors, oxidative stress, mitochondria function, and underlying pathway proteins were analyzed. In vivo, the effects of RSV on renal function and fibrosis were assayed in UUO mice.

RESULTS

Our results showed that low concentrations of RSV (5-20 μM) decreased TGF-β-induced EMT via Sirt1-dependent deacetylation of Smad3/Smad4 mechanism. By contrast, long-term (72 h) exposure to high concentrations of RSV (≥ 40 μM) promoted EMT in HK-2 cells via mitochondrial oxidative stress and ROCK1-mediated disordered cytoskeleton remodeling. In vivo, low-dose treatment of RSV (≤ 25 mg/kg) partly improved renal function, whereas high-dose treatment of RSV (≥ 50 mg/kg) lost its anti-fibrotic role and even aggravated renal fibrosis. However, mice with UUO were more susceptible to high RSV-induced renal injury than normal mice.

CONCLUSION

Dependent on dose, RSV activated either anti-fibrotic or pro-fibrotic effects in kidneys. The risk of RSV consumption in individuals with impaired kidney function should be carefully considered.

CTRP3 inhibits high glucose-induced human glomerular mesangial cell dysfunction

C1q/tumour necrosis factor-related protein-3 (CTRP3) is a member of CTRP family, and its blood level is reduced in human and rodent models of obesity and diabetes. However, the role of CTRP3 in diabetic nephropathy remains unclear. This study was designed to examine the effects of CTRP3 on cell proliferation and extracellular matrix (ECM) accumulation in human glomerular mesangial cells (MCs) in response to high glucose (HG), and explore the potential molecular mechanisms. Our results demonstrated that the expression of CTRP3 was significantly decreased by HG stimulation in MCs. In addition, CTRP3 overexpression inhibited MCs proliferation, reactive oxygen species level, and ECM production in HG-stimulated MCs. Mechanistically, CTRP3 overexpression inhibited the activation of the Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) pathway in HG-stimulated MCs. Taken together, these findings indicated that CTRP3 attenuated HG-induced MC proliferation and ECM production through the inactivation of the JAK2/STAT3 signaling pathway. Thus, CTRP3 may be a potential therapeutic target for the treatment of diabetic nephropathy.

Mangosteen peel extract (Garcinia mangostana L.) as protective agent in glucose-induced mesangial cell as in vitro model of diabetic glomerulosclerosis

OBJECTIVES

This study aims to evaluate the activity of mangosteen peels extract (MPE) as protection agent on induced-glucose mesangial cells (SV40 MES 13 cell line (Glomerular Mesangial Kidney, Mus Musculus)).

MATERIALS AND METHODS

MPE was performed based on maceration method. Cytotoxic assay was performed based on MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) method, while the level of TGF-β1 (Transforming growth factor-β1) and fibronectin in glucose-induced mesangial cells were assayed and determined using ELISA KIT.

RESULTS

In viability assay, MPE 5 and 20 µg/ml has the highest activity to increase cells proliferation in glucose-induced mesangial cells at 5, 10, and 15 days of incubation in glucose concentration (5 and 25 mM) (P<0.05). In inhibitory activity of TGF-β1 and fibronectin level, MPE 5 µg/ml (glucose-induced 5 mM) show the lowest level compared to positive control and other treatments (P<0.05).

CONCLUSION

MPE can increase cell proliferation in glucose-induced mesangial cells and significantly reduce the level of TGF-β1 and fibronectin. MPE activity has correlates to inhibit the diabetic glomerulosclerosis condition and may increase mesangial cell proliferation.

Resveratrol ameliorates sepsis-induced acute kidney injury in a pediatric rat model via Nrf2 signaling pathway

Acute kidney injury (AKI) is a hyper-inflammation-induced abrupt loss of kidney function and has become a major public health problem. The cecal ligation and puncture (CLP) model of peritonitis in rat pups mimics the development of sepsis-induced pediatric AKI is pre-renal without morphological changes of the kidneys and high lethality. Resveratrol, a natural polyphenolic compound with low toxicity, has obvious anti-oxidant and anti-inflammatory properties. The present study aimed to determine whether resveratrol alleviates pediatric AKI and investigated the potential mechanism. Thus, a CLP model of 17-18 day-old rat pups was used to mimic the development of sepsis-induced AKI in children. In the group treated with resveratrol, renal injury induced by CLP was alleviated with downregulation of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and kidney injury molecule (KIM)-1 expression. Nuclear factor-erythroid-2-related factor 2 (Nrf2) signaling is known to effectively inhibit inflammation, the present study found that resveratrol reduced the lipopolysaccharide-induced inflammatory response in kidney cells in vitro and induced the activation of Nrf2 signaling, including accumulation of nuclear Nrf2 and increase of the expression of Nrf2 target genes heme oxygenase (HO)-1 and NAD(P)H dehydrogenase (quinone) 1 (NQO1); this was confirmed by the induction of the expression of HO-1 and NQO1 by treatment of resveratrol in vitro and in vivo. Of note, knockdown of Nrf2 effectively abrogated the downregulation of TNF-α, IL-1β and KIM-1 expression induced by resveratrol in vitro. These results suggested that resveratrol ameliorates sepsis-induced acute kidney injury in a pediatric model of AKI via the Nrf2 signaling pathway.

Artesunate ameliorates high glucose-induced rat glomerular mesangial cell injury by suppressing the TLR4/NF-κB/NLRP3 inflammasome pathway

Inflammatory response is important for the development and progression of diabetic nephropathy (DN). Artesunate (ART), an antimalarial drug, possesses anti-inflammatory effect and exhibits protective effect on chronic kidney diseases. However, the effect of ART on DN is unknown. The aim of the present study was to evaluate the effect and the molecular mechanism of ART on DN in an in vitro model. The rat mesangial cell line, HBZY-1, was induced by high glucose (HG; 30 mM d-glucose) in the presence or absence of ART (15 and 30 μg/ml) and incubated for 24 h. We found that HG induced the proliferation of HBZY-1 cells, while treatment with ART inhibited the cell proliferation. Treatment with ART inhibited HG-induced inflammatory cytokines production and expression of extracellular matrix (ECM). Besides, HG induced reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and inhibited the superoxide dismutase (SOD) activity of HBZY-1 cells, and the effects were attenuated by ART treatment. ART decreased HG-induced the expression levels of toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), nuclear factor κB (NF-κB) p-p65, and nod-like receptor protein 3 (NLRP3). Inhibition of the TLR4/NF-κB pathway suppressed NLRP3 inflammasome in HBZY-1 cells. In conclusion, ART exhibited protective effect on HG-induced HBZY-1 cells by inhibiting the inflammatory response, oxidative stress and ECM accumulation. The TLR4/NF-κB/NLRP3 inflammasome pathway was involved in the protective effect of ART. The results suggested that ART might be a potential therapy agent for the DN treatment.

Spleen tyrosine kinase promotes NLR family pyrin domain containing 3 inflammasome‑mediated IL‑1β secretion via c‑Jun N‑terminal kinase activation and cell apoptosis during diabetic nephropathy

Diabetic nephropathy (DN) is a serious complication of diabetes and can cause an increased mortality risk. It was previously reported that NLR family pyrin domain containing 3 (NLRP3) inflammasome is involved in the pathogenesis of diabetes. However, the underlying mechanism is not clearly understood. In the present study, the effects of spleen tyrosine kinase (Syk) and c-Jun N-terminal kinase (JNK) on the NLRP3 inflammasome were examined in vivo and in vitro. Sprague-Dawley rats were injected intraperitoneally with streptozotocin (65 mg/kg) to induce diabetes. HK2 cells and rat glomerular mesangial cells (RGMCs) were examined to detect the expression of JNK and NLRP3 inflammasome-associated proteins following treatment with a Syk inhibitor or Syk-small interfering (si)RNA in a high glucose condition. In the present study, it was revealed that the protein and mRNA expression levels of NLRP3 inflammasome-associated molecules and the downstream mature interleukin (IL)-1β were upregulated in vivo and in vitro. The Syk inhibitor and Syk-siRNA suppressed high glucose-induced JNK activation, and subsequently downregulated the activation of the NLRP3 inflammasome and mature IL-1β in HK2 cells and RGMCs. Furthermore, high glucose-induced apoptosis of HK2 cells was reduced by the Syk inhibitor BAY61-3606. Therefore, the present results determined that high glucose-induced activation of the NLRP3 inflammasome is mediated by Syk/JNK activation, which subsequently increased the protein expression level of IL-1β and mature IL-1β. The present study identified that the Syk/JNK/NLRP3 signaling pathway may serve a vital role in the pathogenesis of DN.

Tangeretin inhibits high glucose-induced extracellular matrix accumulation in human glomerular mesangial cells

Tangeretin (5, 6, 7, 8, 4'-pentamethoxyflavone), a natural compound extracted from citrus plants, has been shown to possess a variety of pharmacological activities, including anti-oxidant, anti-tumor, cytostatic and anti-diabetic properties. However, the role of tangeretin in diabetic nephropathy (DN) has not yet been investigated. This study was undertaken to elucidate the effects of tangeretin on high glucose (HG)-induced oxidative stress and extracellular matrix (ECM) accumulation in human glomerular mesangial cells (MCs) and explore the underlying mechanisms. Our results showed that tangeretin significantly inhibited HG-induced the proliferation of MCs. In addition, tangeretin dramatically reduced the levels of reactive oxygen species (ROS) and malondialdhyde (MDA), and induced SOD activity, as well as inhibited the expression of fibronectin (FN) and collagen IV in HG-stimulated MCs. Furthermore, tangeretin efficiently prevented the activation of ERK signaling pathway in HG-stimulated MCs. Taken together, these data indicated that tangeretin inhibits HG-induced cell proliferation, oxidative stress and ECM expression in glomerular MCs, at least in part, through the inactivation of ERK signaling pathway. Therefore, tangeretin may be a potential agent in the treatment of DN.

Ursolic Acid Attenuates High Glucose-Mediated Mesangial Cell Injury by Inhibiting the Phosphatidylinositol 3-Kinase/Akt/Mammalian Target of Rapamycin (PI3K/Akt/mTOR) Signaling Pathway

BACKGROUND To investigate the protective effect of ursolic acid (UA) on high glucose (HG)-induced human glomerular mesangial cell injury and to determine whether UA inhibits cell proliferation and reactive oxygen species (ROS) production by suppressing PI3K/Akt/mTOR pathway activation. MATERIAL AND METHODS Human mesangial cells were cultured with normal glucose (NG group), high glucose (HG group), mannitol (mannitol hypertonic control group), or high glucose with different concentrations (0.5, 1.0, and 2.0 mmol/L) of UA (HG+UA groups). Cell proliferation and intracellular ROS levels were assessed by methyl thiazolyl tetrazolium (MTT) and dichloro-dihydro-fluorescein diacetate (DCFH-DA) flow cytometry assays, respectively. Western blotting was used to detect mesangial cell expression of PI3K/Akt/mTOR pathway components, including Akt, p-Akt, mTOR, and p-mTOR, and proteins related to cell injury, including TGF-β1 and fibronectin (FN). mRNA expression of TGF-β1 and FN were evaluated using real-time quantitative polymerase chain reaction (PCR). RESULTS Abnormal proliferation was observed in human glomerular mesangial cells at 48 h after treatment with HG, and UA suppressed the HG-induced proliferation of mesangial cells in a dose-dependent manner. UA inhibited ROS generation and oxidative stress in mesangial cells and mitigated mesangial cell injury. Treatment with UA reduced Akt and mTOR phosphorylation levels in mesangial cells exposed to HG (p<0.05 vs. HG) and downregulated protein and mRNA expression of TGF-β1 and FN in these cells (p<0.05 vs. HG). CONCLUSIONS UA attenuated mesangial cell proliferation and ROS generation by inhibiting HG-mediated PI3K/Akt/mTOR pathway activation, thereby ameliorating mesangial cell damage.

Role of TGF-β activated kinase-1 inhibitor on the interaction between macrophages and mesangial cells on the condition of high glucose

OBJECTIVE

To investigate the effect of TGF-β activated kinase-1(TAK1) inhibitor 5Z-7-oxozeaenol on the interaction between macrophages and mesangial cells exposed to high glucose.

METHODS

The macrophages and mesangial cells were cultured separately or co-cultured and divided into seven groups: inhibitor control group, mannitol control group, normal control group, high glucose group and inhibitor groups. The expression of p-TAK1, TAK1 binding protein (TAB1), transcription factor NF - κ B (NF-κB p65) of macrophages were analyzed by Western blotting. The intracellular localization of NF-κB p65 was analyzed by immunofluorescence. The levels of inflammation cytokines and extracellular matrix were determined by enzyme-linked immune sorbent assay. Migration of macrophages was observed by microscope.

RESULTS

Compared with control group, the expression of p-TAK1, TAB1, NF-κB p65 were significantly higher in high glucose group (P < 0.05). Both in co-culture group and single culture group, the levels of inflammation cytokines and extracellular matrix (P < 0.05) in high glucose group were higher than that in control group. Exposed to high glucose, the levels of inflammation cytokines and extracellular matrix in co-cultured group were higher than that in single culture group (P < 0.05). 5Z-7-oxozeaenol can decrease those cytokines secretion, comparing with high glucose group (P < 0.05). The number of macrophages migration were decreased by 5Z-7-oxozeaenol (P < 0.05).

CONCLUSION

Exposed to high glucose, macrophages and mesangial cells can interact with each other to promote the secretion of inflammation cytokines and extracellular matrix. TAK1 inhibitor can reduce the secretion of inflammation cytokines and extracellular matrix components by intervening NF-κB p65 nuclear transfer and inhibiting macrophage migration.

MicroRNA‑146a/NAPDH oxidase4 decreases reactive oxygen species generation and inflammation in a diabetic nephropathy model

The present study investigated the role of microRNA (miR)‑146a in a diabetic nephropathy (DN) model, and its molecular mechanism. DN mice were given intraperitoneal injections of streptozotocin (55 mg/kg/day) for 5 consecutive days as an in vivo DN model. The HK‑2 human kidney cell line were exposed to 45% D‑glucose as an in vitro DN model. Firstly, it was demonstrated that miR‑146a expression was inhibited and NAPDH oxidase 4 (Nox4) was increased in DN mice. In HK‑2 cells, overexpression of miR‑146a inhibited Nox4 protein expression and decreased reactive oxygen species (ROS) generation, oxidative stress and inflammation, and suppressed vascular cell adhesion molecule‑1 (VCAM‑1) and intracellular adhesion molecule‑1 (ICAM‑1) protein expression. Nacetylcysteine, a Nox4 inhibitor, was demonstrated to inhibit ROS generation, suppress VCAM‑1 and ICAM‑1 protein expression, and decrease oxidative stress and inflammation in HK‑2 cells following overexpression of miR‑146a. In conclusion, these results indicated that miR‑146a/Nox4 decreases ROS generation and inflammation and prevents DN. Therefore, miR‑146a may represent a novel anti‑inflammatory and ‑oxidative modulator of DN.

Free radical scavenging decreases endothelin-1 excretion and glomerular albumin permeability during type 1 diabetes

Increased renal endothelin-1 (ET-1) production and an ET_A receptor-dependent increase in glomerular albumin permeability (P_alb) accompany type 1 diabetes mellitus (T1D). We hypothesized that T1D-induced oxidative stress contributes to renal ET-1 production and glomerular P_alb Male rats with streptozotocin-induced T1D were provided free access to drinking water without additives (T1D rats) or containing the free radical scavenger tempol (1 mmol/L; T1D+Tempol). After 3 weeks, T1D+Tempol rats displayed lower urinary excretion of thiobarbituric acid reactive substances and glomerular superoxide production (dihydroethidium staining) compared to T1D rats. Urinary ET-1 excretion and inner medullary (but not cortical or outer medullary) prepro-ET-1 mRNA expression were lower in the T1D+Tempol group than in the T1D group. P_alb, measured as the change in volume of isolated glomeruli upon exposure to oncotic gradients of albumin, was significantly lower in the T1D+Tempol group than in the T1D group. Tempol treatment did not alter protein excretion or creatinine clearance. These data support the postulate that oxidative stress contributes to glomerular P_alb and renal ET-1 production during the early phase of type 1 diabetes.

Short-term High Dose of Quercetin and Resveratrol Alters Aging Markers in Human Kidney Cells

Background:

Hyperglycemia-mediated oxidative stress implicates in etiology of kidney cell aging and diabetic nephropathy. We evaluated the effects of different doses of resveratrol and quercetin and their combination therapy on aging marker in human kidney cell culture under hyperglycemia condition.

Methods:

Human embryonic kidney cell (HEK-293) was cultured in Dulbecco's Modified Eagle Medium (DMEM) containing 100 mM (18 mg/L) for 24 h. The cells were treated with resveratrol (2.5, 5, 10 μm), quercetin (3, 6, 12 μm), and combination of these (R 2.5 μm, Q 3 μm) and (R 5 μm, Q 6 μm) and (R 10 μm, Q 12 μm) for 48 h, and then, cells were lysed to access RNA and lysate.

Results:

The analysis of data showed that beta-galactosidase enzyme gene expression as an aging marker in all treatment groups has reduced in a dose-dependent manner. Gene expression of Sirtuin1 and thioredoxin (Trx) in all treated groups in comparison to control group increased in a dose-dependent fashion. Trx interacting protein (TXNIP) gene expression decreased in a dose-dependent manner in all treated groups, especially in resveratrol and combination therapy.

Conclusions:

According to the results of this research, quercetin, resveratrol, and especially combination treatments with increased expression levels of antioxidants, can reduce aging markers in HEK cell line in hyperglycemia conditions. These results lead us to use flavonoids such as resveratrol for anti-aging potential.

Effect of Resveratrol on Critical-Sized Calvarial Defects of Diabetic Rats: Histometric and Gene Expression Analysis

PURPOSE

This study investigated the influence of resveratrol (RESV) on the repair of bone critical defects in calvaria of animals with induced diabetes mellitus (DM).

MATERIAL AND METHODS

One hundred rats were divided into 5 groups: induced DM + RESV administration (DM + RESV; n = 20); induced DM plus placebo solution administration (DM + PLAC; n = 20); induced DM plus insulin therapy (DM + INS; n = 20); induced DM plus administration of RES and INS (DM + RESV + INS; n = 20); and nondiabetic controls (NDM; n = 20). DM was induced by intraperitoneal injection of streptozotocin 50 mg/kg 3 days before the surgical procedures. Two critical calvarial defects were created in each animal at the start of the study (day 0). Treatments were administered from day 0 to day 30 of the experiment, when animals were euthanized. One defect was processed for histometric analysis to measure closure of the bone defect. The tissue of the other defect was analyzed for quantification of bone morphogenetic protein-2 (BMP-2), osteopontin, osteoprotegerin, receptor activator of nuclear factor-κB ligand, runt-related transcription factor-2, osterix (Osx), β-catenin, lipoprotein receptor-related protein-5, and dikkop-1 mRNA by quantitative polymerase chain reaction.

RESULTS

Histometric results showed that the DM + RESV, DM + RESV + INS, and NDM groups exhibited greater closure of the bone defects compared with the PLAC- or INS-treated groups (P < .05). Diabetic animals treated with RESV plus INS showed higher levels of BMP-2 and Osx; Osx also was positively increased in animals treated with INS alone (P < .05).

CONCLUSIONS

The use of RESV, regardless of the presence of INS, positively influenced bone repair in animals with induced DM. Further, the combination of INS plus RESV was necessary for the modulation of BMP-2 gene expression.

Combining TRAIL and liquiritin exerts synergistic effects against human gastric cancer cells and xenograft in nude mice through potentiating apoptosis and ROS generation

Gastric cancer is one of the most factors, leading to cancer-related death worldwide. However, the therapies to prevent gastric cancer are still limited and the emergence of drug resistance leads to development of new anti-cancer drugs and combinational chemotherapy regimens. Our study was aimed to explore the anti-gastric cancer effects of liquiritin (LIQ), a major constituent of Glycyrrhiza Radix, which possesses a variety of pharmacological activities. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) preferentially inhibited tumor cells over other normal cells, when used in alone or in combination. The results indicated that LIQ, when applied in single, was moderately effective to suppress proliferation, and migration, as well as to induce apoptosis and reactive oxygen species (ROS) generation of human gastric cancer cell lines, AGS and SNU-216, which are TRAIL-resistant. Significantly, when used in combination, the two drugs functioned synergistically to impede the progression and growth of human gastric cancer cells in vitro and gastric cancer cell xenograft nude mice in vivo. Both intrinsic and extrinsic apoptosis were induced by the two in combination via activating Caspases. And c-Jun N-terminal kinase (JNK) activity was dramatically induced by TRAIL/LIQ. Importantly, TRAIL/LIQ-triggered apoptosis and JNK were dependent on ROS production. The data indicated that application of TRAIL/LIQ in combination had a potential value for clinical use to synergistically prevent human gastric cancer development.