Grape Seed Procyanidin B2 Research Articles

Downregulation of miR-192 Alleviates Oxidative Stress-Induced Porcine Granulosa Cell Injury by Directly Targeting Acvr2a.

Follicular atresia is primarily caused by breakdown to granulosa cells (GCs) due to oxidative stress (OS). MicroRNAs (miRNAs) elicit a defense response against environmental stresses, such as OS, by acting as gene-expression regulators. However, the association between miRNA expression and OS in porcine GCs (PGCs) is unclear. Here, we examined the impact of H2O2-mediated OS in PGCs through miRNA-Seq. We identified 22 (14 upregulated and 8 downregulated) and 33 (19 upregulated and 14 downregulated) differentially expressed miRNAs (DEmiRNAs) at 100 μM and 300 μM H2O2, respectively, compared with the control group. Among the DEmiRNAs, mi-192 was most induced by H2O2-mediated OS, and the downregulation of miR-192 alleviated PGC oxidative injury. The dual-luciferase reporter assay results revealed that miR-192 directly targeted Acvr2a. The Acvr2a level was found to be remarkably decreased after OS. Furthermore, grape seed procyanidin B2 (GSPB2) treatment significantly reduced the H2O2-induced upregulation of miR-192, and decreased PGC apoptosis and oxidative damage. Meanwhile, GSPB2 prevented an H2O2-induced increase in caspase-3 activity, which was enhanced by the application of the miR-192 inhibitor. These results indicate that GSPB2 protects against PGC oxidative injury via the downregulation of miR-192, the upregulation of Acvr2a expression, and the suppression of the caspase-3 apoptotic signaling pathway.

Proteomic analysis of liver mitochondria of db/db mice treated with grape seed procyanidin B2.

Hepatic damage has been recognized as one of the major complications in diabetes mellitus. Our previous studies have verified that grape seed procyanidin B2 (GSPB2) played a protective effect on hepatic damage of diabetes. We used isobaric tag for relative and absolute quantitation proteomics here to identify the alterant mitochondrial protein profile in diabetic liver and to seek the protective targets of GSPB2. Proteomics found that 171 proteins were upregulated or downregulated in the liver mitochondria of diabetic group compared to the control group. Of these proteins, 61 were normalized after GSPB2 treatment. These back-regulated proteins are involved in the process of fatty acid oxidation, tricarboxylic acid cycle, oxidative phosphorylation, oxidative stress, and apoptosis. Some differentially expressed proteins were confirmed by western blotting. Our study might help to better understand the mechanism of mitochondrial dysfunction in diabetic liver damage, and provide novel targets for estimating the protective effects of GSPB2. PRACTICAL APPLICATIONS: Grape seed procyanidin B2 (GSPB2), a polyphenolic component found in red wine and grapes, has beneficial effects such as antioxidative stress, antiapoptosis, and cardiovascular protection. We used proteomics here to identify the differentially expressed mitochondrial proteins in diabetic liver after GSPB2 treatment and to seek the protective targets of GSPB2. We found that the differentially expressed proteins were involved in carbon metabolism, oxidative phosphorylation, fatty acid metabolism, citrate cycle, oxidative stress, and apoptosis. These proteins may play a key role in diabetic hepatic damage as functional proteins. Targeting these proteins including apply of GSPB2 could potentially lead to an effective treatment in the diabetic hepatic disease.

Grape Seed Procyanidin B2 Protects Porcine Ovarian Granulosa Cells against Oxidative Stress-Induced Apoptosis by Upregulating let-7a Expression.

Oxidative stress is a causal factor and key promoter of all kinds of reproductive disorders related to granulosa cell (GC) apoptosis that acts by dysregulating the expression of related genes. Various studies have suggested that grape seed procyanidin B2 (GSPB2) may protect GCs from oxidative injury, though the underlying mechanisms are not fully understood. Therefore, whether the beneficial effects of GSPB2 are associated with microRNAs, which have been suggested to play a critical role in GC apoptosis by regulating the expression of protein-coding genes, was investigated in this study. The results showed that GSPB2 treatment protected GCs from a H2O2-induced apoptosis, as detected by an MTT assay and TUNEL staining, and increased let-7a expression in GCs. Furthermore, let-7a overexpression markedly increased cell viability and inhibited H2O2-induced GC apoptosis. Furthermore, the overexpression of let-7a reduced the upregulation of Fas expression in H2O2-treated GCs at the mRNA and protein levels. Dual-luciferase reporter assay results indicated that let-7a directly targets the Fas 3′-UTR. Furthermore, the overexpression of let-7a enhanced the protective effects of GSPB2 against GC apoptosis induced by H2O2. These results indicate that GSPB2 inhibits H2O2-induced apoptosis of GCs, possibly through the upregulation of let-7a.

The protective effects of grape seed procyanidin B2 against asporin mediates glycated low-density lipoproteininduced-cardiomyocyte apoptosis and fibrosis.

The progression of diabetic cardiomyopathy is related to cardiomyocyte dysfunction and apoptosis. Our previous studies showed that asporin (ASPN) was significantly increased in the myocardium of db/db mice through proteomics, and grape seed procyanidin B2 (GSPB2) significantly inhibited the expression of ASPN in the heart of db/db mice. We reporthere that ASPN played a critical role in glycated low-density lipoproteins (gly-LDL) induced-cardiomyocyte apoptosis. We found that gly-LDL upregulated ASPN expression. ASPN increased H9C2 cardiomyocyteapoptosis with down-regulation of Bcl-2, upregulation of transforming growth factor-β1, Bax, collagen III, fibronectin, and phosphorylation of smad2 and smad3. However, GSPB2 treatment reversed ASPN-induced impairments in H9C2 cardiomyocytes. These results provide evidence for the cardioprotective action of GSPB2 against ASPN injury, and thus suggest a new target for fighting against diabetic cardiomyopathy.

Grape seed procyanidin B2 promotes the autophagy and apoptosis in colorectal cancer cells via regulating PI3K/Akt signaling pathway [Corrigendum

Grape seed procyanidin B2 promotes the autophagy and apoptosis in colorectal cancer cells via regulating PI3K/Akt signaling pathway [Corrigendum] Zhang R, Yu Q, Lu W, et al. Onco Targets Ther. 2019;12:4109–4118.On page 4109, the first sentence of Results in the Abstract section should read from “Results: The in vitro and in vivo data demonstrated that PB2 could promote the apoptosis of CRC cells in a dose-dependent manner, which was significantly reversed by caspase 3 inhibitor.” should read as “Results: The in vitro and in vivo data demonstrated that PB2 could promote the apoptosis of CRC cells in a dose-dependent manner, which was significantly reversed by PI3K inhibitor.”Read the original article

Grape seed procyanidin B2 ameliorates hepatic lipid metabolism disorders in db/db mice.

Diabetes is commonly associated with liver lipid metabolism disorders. AMP-activated protein kinase (AMPK) has a key role in regulating lipid metabolism. Grape seed procyanidin B2 (GSPB2), a natural polyphenol polymer, ameliorates mitochondrial dysfunction and inhibits oxidative stress or apoptosis via AMPK pathways. In the present study, the hypothesis that GSPB2 treatment may ameliorate liver lipid metabolic disorders by activating AMPK and downstream pathways was tested in diabetic mice. Db/m mice were used as controls, and diabetic db/db mice were randomly divided into 2 groups for treatment: Vehicle and GSPB2 (30mg/kg/day for 10weeks). Animals were weighed every week. Fasting blood was collected prior to sacrifice to measure fasting blood glucose (FBG), triglycerides (TG) and total cholesterol (TC). Hepatic TG and free fatty acid (FFA) levels were analyzed. Hepatic sections were examined by light microscopy following hematoxylin and eosin staining. The expression of hepatic AMPK, phosphorylated acetyl‑CoA carboxylase (ACC), carnitine palmitoyl transferase 1 (CPT1) and 4‑hydroxynonenal (4‑HNE) was measured by western blot analysis. Liver mitochondria were isolated to assess electron transport complex I (CI), complex II (CII) and complex IV by high-resolution respirometry. The results demonstrated that GSPB2 significantly decreased body weight and serum TG, TC and FFA levels, but not FBG levels in diabetic mice. GSPB2 visibly decreased lipid droplet accumulation in the liver and significantly reduced hepatic TG and FFA levels. In diabetic mice, GSPB2 restored liver AMPK and ACC phosphorylation, increased CPT1 protein expression, ameliorated lipid peroxidation damage, which was assessed by comparing 4‑HNE levels, and partially restored the damaged mitochondrial respiratory capacity of CI and CII in the liver. In conclusion, long‑term oral treatment with GSPB2 may benefit hepatic lipid metabolism disorders, potentially by decreasing hepatic lipid synthesis and increasing hepatic FFA β‑oxidation via the AMPK‑ACC pathway.

Grape seed procyanidin B2 inhibits adipogenesis of 3T3-L1 cells by targeting peroxisome proliferator-activated receptor γ with miR-483-5p involved mechanism.

Procyanidins have lipolysis effect on adipose metabolism, but the underlying mechanism is not fully understood. The aim of present study was to examine the effect of grape seed procyanidin B2 (GSP) on the adipogenic differentiation of 3T3-L1 preadipocyte cell line and investigate the underlying mechanism. The results showed that GSP treatment significantly reduced the intracellular lipid accumulation in induced 3T3-L1 cells by targeting miR-483-5p as well as peroxisome proliferator-activated receptor γ (PPARγ). In addition, our results revealed that overexpression of miR-483-5p increased adipogenic differentiation, while inhibition of miR-483-5p reduced the lipid accumulation by suppressing the adipogenic differentiation. Moreover, overexpression of miR-483-5p could reverse GSP's inhibition of adipocyte differentiation as well as increase the level of PPARγ. These results demonstrate that GSP inhibits adipogenesis by targeting PPARγ and suggest this effect might be mediated by miR-483-5p.

Critical Role of FoxO1 in Granulosa Cell Apoptosis Caused by Oxidative Stress and Protective Effects of Grape Seed Procyanidin B2.

Reactive oxygen species (ROS) are closely related to the follicular granulosa cell apoptosis. Grape seed procyanidin B2 (GSPB2) has been reported to possess potent antioxidant activity. However, the GSPB2-mediated protective effects and the underlying molecular mechanisms in granulosa cell apoptosis process remain unknown. In this study, we showed for the first time that GSPB2 treatment decreased FoxO1 protein level, improved granulosa cell viability, upregulated LC3-II protein level, and reduced granulosa cell apoptosis rate. Under a condition of oxidative stress, GSPB2 reversed FoxO1 nuclear localization and increased its level in cytoplasm. In addition, FoxO1 knockdown inhibited the protective effects of GSPB2 induced. Our findings suggest that FoxO1 plays a pivotal role in regulating autophagy in granulosa cells, GSPB2 exerts a potent and beneficial role in reducing granulosa cell apoptosis and inducing autophagy process, and targeting FoxO1 could be significant in fighting against oxidative stress-reduced female reproductive system diseases.

Grape seed procyanidin B2 protects podocytes from high glucose-induced mitochondrial dysfunction and apoptosis via the AMPK-SIRT1-PGC-1α axis in vitro.

Grape seed procyanidin B2 (GSPB2) was reported to have protective effects on diabetic nephropathy (DN) as a strong antioxidant. Our previous studies demonstrated that GSPB2 was effective in ameliorating podocyte injury in rats with DN. However, little is known about the benefits of GSPB2 in protecting against podocyte apoptosis and its molecular mechanisms in vitro. In the present study, we investigated whether GSPB2 could protect podocytes from high glucose-induced apoptosis and explored the possible mechanism. Cell viability and apoptosis were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, respectively. The intracellular reactive oxygen species (ROS) level was measured using a dichlorofluorescein diacetate (DCFH-DA) fluorescent probe. Real-time reverse transcription-PCR was used to determine the gene expression of nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM), and quantitative real-time PCR was used to detect mitochondrial DNA (mtDNA) copy number. Western blots were carried out for the related protein expression in podocytes. Our results showed that GSPB2 significantly inhibited high glucose-induced podocyte apoptosis and increased the expression of nephrin and podocalyxin. GSPB2 treatment also suppressed intracellular ROS production and oxidative stress. The mRNA expressions of NRF-1, TFAM and mtDNA copy number were markedly increased, and mitochondrial swelling was effectively reduced in podocytes cultured under high glucose after GSPB2 treatment. The AMPK-SIRT1-PGC-1α axis was also activated by GSPB2 intervention. In conclusion, GSPB2 protected podocytes from high glucose-induced mitochondrial dysfunction and apoptosis via the AMPK-SIRT1-PGC-1α axis in vitro, suggesting a potential role of GSPB2 in the treatment of DN.

Anti-inflammatory effects of grape seed procyanidin B2 on a diabetic pancreas.

The prevalence of type 2 diabetes mellitus (T2DM) has increased considerably in recent years, highlighting the importance of developing new therapeutic strategies. Insulin-resistance and gradual dysfunction of pancreatic islets are the mainstay in the progression of T2DM. Therefore, preserving the function of the pancreas may lead to new prospective approaches. Our previous studies suggested that grape seed procyanidin B2 (GSPB2), a natural polyphenol product, exhibited protective effects on diabetic vasculopathy. However, effects of GSPB2 on a diabetic pancreas remain unknown. In this study, we provided strong evidence that GSPB2 exerted protective effects on a diabetic pancreas. GSPB2 attenuated the elevated body weights, food intake and advanced glycation end-product (AGE) levels in db/db mice (p < 0.05), though it had no significant effect on glucose levels. The increased islet sizes, insulin levels, as well as HOMA-IR were also improved by GSPB2 treatment in db/db mice (p < 0.05). Milk fat globule epidermal growth factor-8 (MFG-E8), an estimated target of GSPB2 in our previous studies, was up-regulated in pancreatic tissues whereas GSPB2 treatment down-regulated the protein level (p < 0.05). Since MFG-E8 is highly involved in inflammation, we further investigate pro-inflammatory cytokines interleukin-1β (IL-1β) and NLRP3 levels. We found that levels of IL-1β and NLRP3 increased in a diabetic pancreas while GSPB2 treatment notably attenuated these alterations (p < 0.05). In conclusion, our results suggest that inflammation is involved in the damage of a diabetic pancreas and GSPB2 provides protective effects at least in part through anti-inflammation.

Critical Role of Prohibitin in Endothelial Cell Apoptosis Caused by Glycated Low-density Lipoproteins and Protective Effects of Grape Seed Procyanidin B2

Elevated level of glycated low-density lipoproteins (glyLDL) is believed to contribute to endothelial dysfunction, which is involved in the pathogenesis and acceleration of diabetic vascular diseases. Grape seed procyanidin B2 (GSPB2) has been reported to possess protective effects against endothelial dysfunction. However, the underlying mechanism remains unclear. Prohibitin (PHB) is a multifunctional protein implicated in cellular survival and apoptosis. In this study, we showed that glyLDL treatment decreased protein level of PHB, reduced viability, and increased apoptosis in human umbilical vein endothelial cells (HUVEC). PHB overexpression or GSPB2 significantly attenuated apoptosis induced by glyLDL. Moreover, PHB siRNA increased HUVEC apoptosis, along with defective mitochondria and increased levels of cytosol cytochrome c concentration, caspase-3 activity, Bax/Bcl-2 ratio, and phosphorylated Akt, whereas PHB overexpression or GSPB2 restored these changes. Our study identified PHB as an important player responsible for HUVEC apoptosis induced by glyLDL. GSPB2 protected against HUVEC apoptosis at least in part through upregulating PHB. Targeting PHB could be significant in fighting against diabetic vascular complications.

Grape seed procyanidin B2 ameliorates mitochondrial dysfunction and inhibits apoptosis via the AMP-activated protein kinase-silent mating type information regulation 2 homologue 1-PPARγ co-activator-1α axis in rat mesangial cells under high-dose glucosamine.

Grape seed procyanidin B2 (GSPB2), an antioxidative and anti-inflammatory polyphenol in grape seed, has been found to have protective effects on diabetic nephropathy. Based on its favourable biological activities, in the present study, we aimed to investigate whether GSPB2 could inhibit apoptosis in rat mesangial cells treated with glucosamine (GlcN) under high-dose conditions. The results showed that the administration of GSPB2 (10 μg/ml) significantly increased the viability of mesangial cells treated with GlcN at a dose of 15 mM. We found that GSPB2 inhibited apoptosis in mesangial cells using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphates (dUTP) nick-end labelling staining and flow cytometry technique (P< 0·05 for both). GSPB2 treatment also suppressed oxidative stress by elevating the activity of glutathione peroxidase (P< 0·05) and superoxide dismutase (P< 0·01), as well as prevented cellular damage. GSPB2 enhanced the mRNA expression of nuclear respiratory factor 1, mitochondrial transcription factor A and mitochondrial DNA copy number in mesangial cells as determined by real-time PCR (P< 0·05 for each). Finally, GSPB2 treatment activated the protein expression of PPARγ co-activator-1α (PGC-1α), silent mating type information regulation 2 homologue 1 (SIRT1) and AMP-activated protein kinase (AMPK) in mesangial cells. These findings suggest that GSPB2 markedly ameliorates mitochondrial dysfunction and inhibits apoptosis in rat mesangial cells treated with high-dose GlcN. This protective effect could be, at least in part, due to the activation of the AMPK-SIRT1-PGC-1α axis.

Quantitative proteomics study of protective effects of grape seed procyanidin B2 on diabetic cardiomyopathy in db/db mice.

Diabetic cardiomyopathy is one of the major complications of diabetes mellitus. Oxidative stress appears to play a substantial role in cardiomyopathy. Grape seed procyanidin B2 (GSPB2) has been known as an anti-oxidant in treating diabetes mellitus; however, little is known about its effects and underlying mechanisms on diabetic cardiomyopathy. The present study is to explore the molecular targets of GSPB2 responsible for the anti-oxidative effects in db/db mice by quantitative proteomics. GSPB2 (30 mg/kg body weight/day) were intragastric administrated to db/db mice for 10 weeks. Proteomics of the heart tissue extracts by isobaric tags for relative and absolute quantification analysis was obtained from db/db mice. Our study provides important evidence that GSPB2 protect against cardiomyopathy in diabetes mellitus, which are believed to result from regulating the expression of key proteins involving cardiac fibrosis and proliferation. GSPB2 could be expected to become novel clinical application in fighting against diabetic cardiomyopathy.

PIMT Prevents the Apoptosis of Endothelial Cells in Response to Glycated Low Density Lipoproteins and Protective Effects of Grape Seed Procyanidin B2

BackgroundThe development of diabetic angiopathy is associated with profound vascular endothelial cells (VEC) dysfunction and apoptosis. Glycated low density lipoproteins (gly-LDL) continuously produced in the setting of diabetic patients play an important role in causing VEC dysfunction and apoptosis. However, the underlying molecular mechanism remains largely elusive. Protein L-isoaspartyl methyltransferase (PIMT) is a widely expressed protein repair enzyme by multiple cell types of arterial wall including VEC. Our previous proteomic studies showed that the expression of PIMT was significantly decreased in the aorta of diabetic rats as compared with control rats and treatment with grape seed procyanidin extracts significantly increased the PIMT expression in diabetic rats. We hypothesized that PIMT plays a critical role in gly-LDL induced VEC apoptosis; grape seed procyanidin B2 (GSPB2) protect against gly-LDL induced VEC apoptosis through PIMT regulation.Methods and ResultsHUVEC transfected negative control and PIMT siRNA were treated with or without GSPB2 (10 µmol/L) for 48 h. Moreover, HUVEC of PIMT overexpression were stimulated by gly-LDL (50 µg/ml) in the presence or absence of GSPB2 (10 µmol/L) for 48 h. Our results showed that gly-LDL downregulated PIMT expression and PIMT overexpression or GSPB2 significantly attenuated gly-LDL induced VEC apoptosis. PIMT siRNA increased VEC apoptosis with up-regulation of p53, cytochrome c release, caspase-9 and caspase-3 activation. Mechanistically, overexpression of PIMT or GSPB2 increased the phosphorylation of ERK1/2 and GSK3β in the gly-LDL induced VEC.ConclusionIn summary, our study identified PIMT as a key player responsible for gly-LDL induced VEC apoptosis and GSPB2 protect against gly-LDL induced VEC apoptosis by PIMT up-regulation. Targeting PIMT including use of GSPB2 could be turned into clinical application in the fighting against diabetic vascular complications.

Proteomic analysis of kidney and protective effects of grape seed procyanidin B2 in db/db mice indicate MFG-E8 as a key molecule in the development of diabetic nephropathy

Diabetic nephropathy, as a severe microvascular complication of diabetic mellitus, has become the leading cause of end-stage renal diseases. However, no effective therapeutic strategy has been developed to prevent renal damage progression to end stage renal disease. Hence, the present study evaluated the protective effects of grape seed procyanidin B2 (GSPB2) and explored its molecular targets underlying diabetic nephropathy by a comprehensive quantitative proteomic analysis in db/db mice. Here, we found that oral administration of GSPB2 significantly attenuated the renal dysfunction and pathological changes in db/db mice. Proteome analysis by isobaric tags for relative and absolute quantification (iTRAQ) identified 53 down-regulated and 60 up-regulated proteins after treatment with GSPB2 in db/db mice. Western blot analysis confirmed that milk fat globule EGF-8 (MFG-E8) was significantly up-regulated in diabetic kidney. MFG-E8 silencing by transfection of MFG-E8 shRNA improved renal histological lesions by inhibiting phosphorylation of extracellular signal-regulated kinase1/2 (ERK1⁄2), Akt and glycogen synthase kinase-3beta (GSK-3β) in kidneys of db/db mice. In contrast, over-expression of MFG-E8 by injection of recombinant MFG-E8 resulted in the opposite effects. GSPB2 treatment significantly decreased protein levels of MFG-E8, phospho-ERK1/2, phospho-Akt, and phospho-GSK-3β in the kidneys of db/db mice. These findings yield insights into the pathogenesis of diabetic nephropathy, revealing MFG-E8 as a new therapeutic target and indicating GSPB2 as a prospective therapy by down-regulation of MFG-E8, along with ERK1/2, Akt and GSK-3β signaling pathway.

PIMT Prevents the Apoptosis of Endothelial Cells in Response to Glycated Low Density Lipoproteins and Protective Effects of Grape Seed Procyanidin B2

PIMT Prevents the Apoptosis of Endothelial Cells in Response to Glycated Low Density Lipoproteins and Protective Effects of Grape Seed Procyanidin B2

Proteomic Analysis of Aorta and Protective Effects of Grape Seed Procyanidin B2 in db/db Mice Reveal a Critical Role of Milk Fat Globule Epidermal Growth Factor-8 in Diabetic Arterial Damage

BackgroundAtherosclerosis is one of the major complications of type 2 diabetic patients (T2DM), leading to morbidity and mortality. Grape seed procyanidin B2 (GSPB2) has demonstrated protective effect against atherosclerosis, which is believed to be, at least in part, a result of its antioxidative effects. The aim of this study is to identify the target protein of GSPB2 responsible for the protective effect against atherosclerosis in patients with DM.Methods and ResultsGSPB2 (30 mg/kg body weight/day) were administrated to db/db mice for 10 weeks. Proteomics of the aorta extracts by iTRAQ analysis was obtained from db/db mice. The results showed that expression of 557 proteins were either up- or down-regulated in the aorta of diabetic mice. Among those proteins, 139 proteins were normalized by GSPB2 to the levels comparable to those in control mice. Among the proteins regulated by GSPB2, the milk fat globule epidermal growth factor-8 (MFG-E8) was found to be increased in serum level in T2DM patients; the serum level of MFG-E8 was positively correlated with carotid-femoral pulse wave velocity (CF-PWV). Inhibition of MFG-E8 by RNA interference significantly suppressed whereas exogenous recombinant MFG-E8 administration exacerbated atherogenesis the db/db mice. To gain more insights into the mechanism of action of MFG-E8, we investigated the effects of MFG-E8 on the signal pathway involving the extracellular signal-regulated kinase (ERK) and monocyte chemoattractant protein-1 (MCP-1). Treatment with recombinant MFG-E8 led to increased whereas inhibition of MFG-E8 to decreased expression of MCP-1 and phosphorylation of ERK1/2.ConclusionOur data suggests that MFG-E8 plays an important role in atherogenesis in diabetes through both ERK and MCP-1 signaling pathways. GSPB2, a well-studied antioxidant, significantly inhibited the arterial wall changes favoring atherogenesis in db/db mice by down-regulating MFG-E8 expression in aorta and its serum level. Measuring MFG-E8 serum level could be a useful clinical surrogate prognosticating atherogenesis in DM patients.

Proteomic Analysis of Aorta and Protective Effects of Grape Seed Procyanidin B2 in db/db Mice Reveal a Critical Role of Milk Fat Globule Epidermal Growth Factor-8 in Diabetic Arterial Damage

Proteomic Analysis of Aorta and Protective Effects of Grape Seed Procyanidin B2 in db/db Mice Reveal a Critical Role of Milk Fat Globule Epidermal Growth Factor-8 in Diabetic Arterial Damage

Grape Seed Procyanidin B2 Inhibits Human Aortic Smooth Muscle Cell Proliferation and Migration Induced by Advanced Glycation End Products

Advanced glycation end product (AGE)-induced vascular smooth muscle cell (VSMC) proliferation is vital to the progression of diabetic vasculopathy. A grape seed procyanidin extract has been reported to possess anti-oxidative and anti-inflammatory properties and to display a significant cardiovascular protective effect, but little is know about the underlying mechanism. The objective of this present study was to determine whether GSPB2 (grape seed procyanidin B2), which is a dimeric procyanidin and more biologically active, could inhibit AGE-induced VSMC proliferation by affecting the production of ubiquitin COOH-terminal hydrolase 1 (UCH-L1), the degradation of IκB-α and nuclear translocation of NF-κB in human aortic smooth muscle cells (HASMCs). Our data show that GSPB2 preincubation markedly inhibited AGE-induced proliferation and migration of HASMCs in a dose-dependent manner and upregulated the protein level of UCH-L1. Further studies revealed that the GSPB2 pretreatment markedly attenuated the degradation of IκB-α and nuclear translocation of NF-κB by modulating ubiquitination of IκB-α in AGE-exposed HASMCs. These results collectively suggest that AGE-induced HASMC proliferation and migration was suppressed by GSPB2 through regulating UCH-L1 and ubiquitination of IκB-α. GSPB2 may therefore have therapeutic potential in preventing and treating vascular complications of diabetes mellitus.

Grape seed procyanidin B2 inhibits advanced glycation end product‐induced endothelial cell apoptosis through regulating GSK3β phosphorylation

To investigate the effects of GSPB2 (grape seed procyanidin B2) on the apoptosis of HUVECs (human umbilical endothelial cells) induced by AGEs (advanced glycation end products), HUVECs were treated with AGEs (200 μg/ml) in the presence or absence of GSPB2 (2.5, 5.0 and 10.0 μmol/l). Our findings showed that (i) AGEs induced HUVEC apoptosis and up-regulated the expression of caspase-3 activation and lactadherin and reduced the phosphorylation of GSK3β (glycogen synthase kinase 3β) at baseline. (ii) Treatment of HUVEC with GSPB2 significantly inhibited the cell apoptosis and the expression of caspase-3 activation and lactadherin induced by AGEs. Moreover, GSPB2 inhibited intracellular reactive oxygen species in a dose-dependent manner in AGEs-treated cells as determined by flow cytometry. (iii) GSPB2 increased the phosphorylation of GSK3β of HUVEC in response to AGEs. These findings suggest that the signalling pathway involving phosphorylation of GSK3β and lactadherin might play a key role in the endothelial apoptosis. GSPB2 therapy could become an effective approach to battling AGEs-induced endothelial apoptosis.