Treatment with β-sitosterol ameliorates the effects of cerebral ischemia/reperfusion injury by suppressing cholesterol overload, endoplasmic reticulum stress, and apoptosis

β-Sitosterol is a type of phytosterol that occurs naturally in plants.Previous studies have shown that it has anti-oxidant,anti-hyperlipidemic,anti-inflammatory,immunomodulatory,and anti-tumor effects,but it is unknown whetherβ-sitosterol treatment reduces the effects of ischemic stroke.Here we found that,in a mouse model of ischemic stroke induced by middle cerebral artery occlusion,β-sitosterol reduced the volume of cerebral infarction and brain edema,reduced neuronal apoptosis in brain tissue,and alleviated neurological dysfunction;moreover,β-sitosterol increased the activity of oxygen-and glucose-deprived cerebral cortex neurons and reduced apoptosis.Further investigation showed that the neuroprotective effects ofβ-sitosterol may be related to inhibition of endoplasmic reticulum stress caused by intracellular cholesterol accumulation after ischemic stroke.In addition,β-sitosterol showed high affinity for NPC1L1,a key transporter of cholesterol,and antagonized its activity.In conclusion,β-sitosterol may help treat ischemic stroke by inhibiting neuronal intracellular cholesterol overload/endoplasmic reticulum stress/apoptosis signaling pathways.

GPER agonist G1 suppresses neuronal apoptosis mediated by endoplasmic reticulum stress after cerebral ischemia/reperfusion injury

Studies have confirmed a strong association between activation of the endoplasmic reticulum stress pathway and cerebral ischemia/reperfusion(I/R) injury.In this study,three key proteins in the endoplasmic reticulum stress pathway(glucose-regulated protein 78,caspase-12,and C/EBP homologous protein) were selected to examine the potential mechanism of endoplasmic reticulum stress in the neuroprotective effect of G protein-coupled estrogen receptor.Female Sprague-Dawley rats received ovariectomy(OVX),and then cerebral I/R rat models(OVX+ I/R) were established by middle cerebral artery occlusion.Immediately after I/R,rat models were injected with 100 μg/kg E2(OVX + I/R +E2),or 100 μg/kg G protein-coupled estrogen receptor agonist G1(OVX + I/R + G1) in the lateral ventricle.Longa scoring was used to detect neurobehavioral changes in each group.Infarct volumes were measured by 2,3,5-triphenyltetrazolium chloride staining.Morphological changes in neurons were observed by Nissl staining.Terminal dexynucleotidyl transferase-mediated nick end-labeling staining revealed that compared with the OVX + I/R group,neurological function was remarkably improved,infarct volume was reduced,number of normal Nissl bodies was dramatically increased,and number of apoptotic neurons in the hippocampus was decreased after E2 and G1 intervention.To detect the expression and distribution of endoplasmic reticulum stress-related proteins in the endoplasmic reticulum,caspase-12 distribution and expression were detected by immunofluorescence,and mRNA and protein levels of glucose-regulated protein 78,caspase-12,and C/EBP homologous protein were determined by polymerase chain reaction and western blot assay.The results showed that compared with the OVX+ I/R group,E2 and G1 treatment obviously decreased mRNA and protein expression levels of glucose-regulated protein 78,C/EBP homologous protein,and caspase-12.However,the G protein-coupled estrogen receptor antagonist G15(OVX + I/R + E2 + G15) could eliminate the effect of E2 on cerebral I/R injury.These results confirm that E2 and G protein-coupled estrogen receptor can inhibit the expression of endoplasmic reticulum stress-related proteins and neuronal apoptosis in the hippocampus,thereby improving dysfunction caused by cerebral I/R injury.Every experimental protocol was approved by the Institutional Ethics Review Board at the First Affiliated Hospital of Shihezi University School of Medicine,China(approval No.SHZ A2017-171) on February 27,2017.

Silencing Huwe1 reduces apoptosis of cortical neurons exposed to oxygen-glucose deprivation and reperfusion

HECT, UBA and WWE domain-containing 1(Huwe1), an E3 ubiquitin ligase involved in the ubiquitin-proteasome system, is widely expressed in brain tissue. Huwe1 is involved in the turnover of numerous substrates, including p53, Mcl-1, Cdc6 and N-myc, thereby playing a critical role in apoptosis and neurogenesis. However, the role of Huwe1 in brain ischemia and reperfusion injury remains unclear. Therefore, in this study, we investigated the role of Huwe1 in an in vitro model of ischemia and reperfusion injury. At 3 days in vitro, primary cortical neurons were transduced with a control or shRNA-Huwe1 lentiviral vector to silence expression of Huwe1. At 7 days in vitro, the cells were exposed to oxygen-glucose deprivation for 3 hours and reperfusion for 24 hours. To examine the role of the c-Jun N-terminal kinase(JNK)/p38 pathway, cortical neurons were pretreated with a JNK inhibitor(SP600125) or a p38 MAPK inhibitor(SB203508) for 30 minutes at 7 days in vitro, followed by ischemia and reperfusion. Neuronal apoptosis was assessed by TUNEL assay. Protein expression levels of JNK and p38 MAPK and of apoptosis-related proteins(p53, Gadd45 a, cleaved caspase-3, Bax and Bcl-2) were measured by western blot assay. Immunofluorescence labeling for cleaved caspase-3 was performed. We observed a significant increase in neuronal apoptosis and Huwe1 expression after ischemia and reperfusion. Treatment with the shRNA-Huwe1 lentiviral vector markedly decreased Huwe1 levels, and significantly decreased the number of TUNEL-positive cells after ischemia and reperfusion. The silencing vector also downregulated the pro-apoptotic proteins Bax and cleaved caspase-3, and upregulated the anti-apoptotic proteins Gadd45 a and Bcl-2. Silencing Huwe1 also significantly reduced p-JNK levels and increased p-p38 levels. Our findings show that downregulating Huwe1 affects the JNK and p38 MAPK signaling pathways as well as the expression of apoptosis-related genes to provide neuroprotection during ischemia and reperfusion. All animal experiments and procedures were approved by the Animal Ethics Committee of Sichuan University, China in January 2018(approval No. 2018013).

Treadmill training improves neurological deficits and suppresses neuronal apoptosis in cerebral ischemic stroke rats

RehabilNation training is believed to be beneficial to patients with stroke, but its molecular mechanism is still unclear. Rat models of cerebral ischemic stroke were established by middle cerebral artery occlusion/reperfusion, and then received treadmill training of different intens让ies, twice a day for 30 minutes for 1 week. Low-intensity training was conducted at 5 m/min, with a 10-minute running, 10-minute rest, and 10-minute running cycle. In the moderate-intensity training, the intensity gradually increased from 5 m/min to 10 m/min in 5 minutes, with the same rest cycle as above. In high-intensity training, the intensity gradually increased from 5 m/min to 25 m/min in 5 minutes, with the same rest cycle as above. The Bederson scale was used to evaluate the improvement of motor function. Infarct volume was detected using 2,3,5-triphenyltetrazolium chloride staining. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining was applied to detect the apoptosis of nerve cells in brain tissue. Western blot assay was employed to analyze the activation of cyclic adenosine monophosphate (cAMP)/protein kinase A and Akt/glycogen synthase kinase-3卩 signaling pathways in rat brain tissue. All training intensities reduced the neurological deficit score, infarct volume, and apoptosis in nerve cells in brain tissue of stroke rats. Training intensities activated the cAMP/protein kinase A and Akt/glycogen synthase kinase-3 beta signaling pathways. This activation was more obvious with higher training intensities. These changes were reversed by intracerebroventricular injection of protein kinase A inhibitor Rp-cAMP. Our findings indicate that the neuroprotective effect of rehabilitation training is achieved via activation of the cAMP/ protein kinase A and Akt/glycogen synthase kinase-3 beta signaling pathways. This study was approved by the Ethics Committee of Animal Experimentation in Shanghai No. 8 Peoples Hospital, China.

JTE-522-induced apoptosis in human gastric adenocarinoma cell line AGS cells by caspase activation accompanying cytochrome C release,membrane translocation of Bax and loss of mitochondrial membrane potential

AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (Deltapsim). METHODS: Cell culture, cell counting, ELISA assay, TUNEL, flow cytometry, Western blot and fluorometric assay were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanism. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Caspases 8 and 9 were activated during apoptosis as judged by the appearance of cleavage products from procaspase and the caspase activities to cleave specific fluorogenic substrates. To elucidate whether the activation of caspases 8 and 9 was required for the apoptosis induction, we examined the effect of caspase-specific inhibitors on apoptosis. The results showed that caspase inhibitors significantly inhibited the apoptosis induced by JTE-522. In addition, the membrane translocation of Bax and cytosolic release of cytochrome C accompanying with the decrease of the uptake of Rhodamin 123, were detected at an early stage of apoptosis. Furthermore, Bax translocation, cytochrome C release, and caspase 9 activation were blocked by Z-VAD.fmk and Z-IETD-CHO. CONCLUSION: The present data indicate a crucial association between activation of caspases 8, 9, cytochrome C release, membrane translocation of Bax, loss of Deltapsim and JTE-522-induced apoptosis in AGS cells.

Mechanism of stilbene glycosides on apoptosis of SH-SY5Y cells via regulating PI3K/AKT signaling pathway

Objective:To investigate the effects of stilbene glycoside(TSG)on okadaic acid-induced apoptosis in human neuroblastoma cells(SH-SY5Y)via the PI3K/AKT pathway.Methods:The optimal concentration of OA was screened by CCK-8 assay,and SH-SY5Y cells were divided into control group,model group,TSG group,LY294002 group and LY294002+TSG group.The proliferation and apoptosis in each group were detected by CCK-8 and TUNEL assays;Western blotting method and real-time fluorescence quantitative polymerase chain reaction was used to detect the expression of PI3K,P-PI3K(Y607),AKT,P-AKT(Ser473),Bcl-2 and Bax proteins.The relative protein expression was represented by P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax gray ratio.Results:CCK-8 screened the optimal concentration of OA as 40 nmol/L.Compared with the control group,the model group increased relative cell viability,decreased apoptosis rate,the pathway and apoptotic proteins expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax were decreased,and the mRNA expression levels of PI3K,AKT and Bcl-2 were decreased.Bax mRNA expression level increased(P<0.05);Compared with model group,TSG group increased relative cell viability,decreased apoptosis rate,increased protein expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT,Bcl-2/Bax,and increased mRNA expression levels of PI3K,AKT,and Bcl-2.Bax mRNA expression decreased(P<0.05),LY294002 group decreased relative cell viability,increased apoptosis rate,P-PI3K(Y607)/PI3K protein expression levels were significantly decreased(P<0.05),P-AKT(Ser473)/AKT and Bcl-2/Bax protein expression levels were significantly decreased,but there was no statistical significance,PI3K,AKT and Bcl-2 mRNA expression levels were decreased,and Bax mRNA expression levels were increased(all P<0.05);Compared with LY294002 group,LY294002+TSG group increased relative cell viability,decreased apoptosis rate,and the protein expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax were increased.The mRNA expression levels of PI3K,AKT,Bcl-2 were increased,Bax was decreased(all P<0.05).Conclusion:Stilbene glycoside may alleviate okadaic acid-induced apoptosis in SH-SY5Y cells by interfering with the PI3K/AKT signaling pathway,which in turn regulates the expression of apoptotic factors such as Bcl-2 and Bax.

The involvement of p38 MAPK in transforming growth factor β1-induced apoptosis in murine hepatocytes

We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly inhibited the TGF-beta1-induced apoptosis and PAI-1 promoter activity. Treatment of cells with TGF-beta1 activates p38. Furthermore, over-expression of dominant negative mutant p38 also reduced the TGF-beta1-induced apoptosis. The data indicate that the activation of p38 is involved in TGF-beta1-mediated gene expression and apoptosis.

Gambogic acid induces apoptosis and inhibits colorectal tumor growth via mitochondrial pathways

AIM: To investigate the effect of gambogic acid(GA) on apoptosis in the HT-29 human colon cancer cell line. METHODS: H-29 cells were used for in vitro experiments in this study. Relative cell viability was assessed using MTT assays. Cell apoptosis was detected by terminal deoxynucleotidyl transferase d UTP nick end labeling and Hoechst 33342 staining, and quantified by flow cytometry. Cellular ultrastructure was observed by transmission electron microscopy. Real-time PCR and Western blot analyses were used to evaluate gene and protein expression levels. For in vivo experiments, BALB/c nude mice received subcutaneous injections of HT-29 cells in the right armpit. When well-established xenografts were palpable with a tumor size of 75 mm3, mice were randomly assigned to a vehicle(negative) control, positive control or GA treatment group(n = 6 each). The animals in the treatment group received one of three dosages of GA(in saline; 5, 10 or 20 mg/kg) via the caudal vein twice weekly, whereas animals in the negative and positive control groups were given equal volumes of 0.9% saline or 10 mg/kg docetaxel, respectively, via the caudal vein once weekly. RESULTS: The cell viability assay showed that GA inhibited proliferation of HT-29 cells in a dose- and time-dependent manner after treatment with GA(0.00, 0.31, 0.62, 1.25, 2.50, 5.00 or 10.00 μmol/L) for 24, 48 or 72 h. After 48 h, the percentage of apoptotic cells in cells treated with 0.00, 1.25, 2.50 and 5.00 μmol/L GA was 1.4% ± 0.3%, 9.8% ± 1.2%, 25.7% ± 3.3% and 49.3% ± 5.8%, respectively. Ultrastructural analysis of HT-29 cells treated for 48 h with 2.5μmol/L GA revealed apoptotic bodies and condensed and fragmented nuclei. Levels of caspase-8,-9 and-3 m RNAs were significantly increased after treatment with GA(1.25, 2.50 or 5.00 μmol/L) for 48 h(P < 0.05 for all). Protein levels of apoptosis-related factors Fas, Fas L, FADD, cytochrome c, and Apaf-1 were increased in GA-treated cells, whereas levels of pro-caspase-8,-9 and-3 were significantly decreased(P < 0.05 for all). Furthermore, GA significantly and dose-dependently inhibited the growth of HT-29 tumors in a mouse xenograft model(P < 0.05).CONCLUSION: GA inhibits HT-29 proliferation via induction of apoptosis. The anti-cancer effects are likely mediated by death receptor(extrinsic) and mitochondrial(intrinsic) pathways.

AAV2-PDE6B restores retinal structure and function in the retinal degeneration 10 mouse model of retinitis pigmentosa by promoting phototransduction and inhibiting apoptosis

Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death.However,there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation.Adeno-associated virus(AAV)-mediated gene therapy is a promising strategy for treating retinitis pigmentosa.The aim of this study was to explore the molecular mechanisms by which AAV2-PDE6B rescues retinal function.To do this,we injected retinal degeneration 10(rd10)mice subretinally with AAV2-PDE6B and assessed the therapeutic effects on retinal function and structure using dark-and light-adapted electroretinogram,optical coherence tomography,and immunofluorescence.Data-independent acquisition-mass spectrometry-based proteomic analysis was conducted to investigate protein expression levels and pathway enrichment,and the results from this analysis were verified by real-time polymerase chain reaction and western blotting.AAV2-PDE6B injection significantly upregulated PDE6βexpression,preserved electroretinogram responses,and preserved outer nuclear layer thickness in rd10 mice.Differentially expressed proteins between wild-type and rd10 mice were closely related to visual perception,and treating rd10 mice with AAV2-PDE6B restored differentially expressed protein expression to levels similar to those seen in wild-type mice.Kyoto Encyclopedia of Genes and Genome analysis showed that the differentially expressed proteins whose expression was most significantly altered by AAV2-PDE6B injection were enriched in phototransduction pathways.Furthermore,the phototransductionrelated proteins Pde6α,Rom1,Rho,Aldh1a1,and Rbp1 exhibited opposite expression patterns in rd10 mice with or without AAV2-PDE6B treatment.Finally,Bax/Bcl-2,p-ERK/ERK,and p-c-Fos/c-Fos expression levels decreased in rd10 mice following AAV2-PDE6B treatment.Our data suggest that AAV2-PDE6B-mediated gene therapy promotes phototransduction and inhibits apoptosis by inhibiting the ERK signaling pathway and upregulating Bcl-2/Bax expression in retinitis pigmentosa.

P7C3-A20 treats traumatic brain injury in rats by inhibiting excessive autophagy and apoptosis

Traumatic brain injury is a severe health problem leading to autophagy and apoptosis in the brain.3,6-Dibromo-beta-fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine(P7C3-A20)can be neuroprotective in various diseases,including ischemic stroke and neurodegenerative diseases.However,whether P7C3-A20 has a therapeutic effect on traumatic brain injury and its possible molecular mechanisms are unclear.Therefore,in the present study,we investigated the therapeutic effects of P7C3-A20 on traumatic brain injury and explored the putative underlying molecular mechanisms.We established a traumatic brain injury rat model using a modified weight drop method.P7C3-A20 or vehicle was injected intraperitoneally after traumatic brain injury.Severe neurological deficits were found in rats after traumatic brain injury,with deterioration in balance,walking function,and learning memory.Furthermore,hematoxylin and eosin staining showed significant neuronal cell damage,while terminal deoxynucleotidyl transferase mediated dUTP nick end labeling staining indicated a high rate of apoptosis.The presence of autolysosomes was observed using transmission electron microscope.P7C3-A20 treatment reversed these pathological features.Western blotting showed that P7C3-A20 treatment reduced microtubule-associated protein 1 light chain 3-Ⅱ(LC3-Ⅱ)autophagy protein,apoptosis-related proteins(namely,Bcl-2/adenovirus E1B 19-kDa-interacting protein 3[BNIP3],and Bcl-2 associated x protein[Bax]),and elevated ubiquitin-binding protein p62(p62)autophagy protein expression.Thus,P7C3-A20 can treat traumatic brain injury in rats by inhibiting excessive autophagy and apoptosis.

3-N-Butylphthalide mitigates high glucose-induced injury to Schwann cells:association with nitrosation and apoptosis

A high glucose state readily causes peripheral axon atrophy, demyelination, loss of nerve fiber function, and delayed regeneration. However, few studies have examined whether nitration is also critical for diabetic peripheral neuropathy. Therefore, this study investigated the effects of high glucose on proliferation, apoptosis, and 3-nitrotyrosine levels of Schwann cells treated with butylphthalide. In addition, we explored potential protective mechanisms of butylphthalide on peripheral nerves. Schwann cells were cultured in vitro with high glucose then stimulated with the peroxynitrite anion inhibitors uric acid and 3-n-butylphthalide for 48 hours. Cell Counting Kit-8 and flow cytometry were used to investigate the effects of uric acid and 3-n-butylphthalide on proliferation and apoptosis of Schwann cells exposed to a high glucose environment. Effects of uric acid and 3-n-butylphthalide on levels of 3-nitrotyrosine in Schwann cells were detected by enzyme-linked immunosorbent assay. The results indicated that Schwann cells cultured in high glucose showed decreased proliferation, but increased apoptosis and intracellular 3-nitrotyrosine levels. However, intervention with uric acid or 3-n-butylphthalide could increase proliferation of Schwann cells cultured in high glucose, and inhibited apoptosis and intracellular 3-nitrotyrosine levels. According to our data, 3-n-butylphthalide may inhibit cell nitrification and apoptosis, and promote cell proliferation, thereby reducing damage to Schwann cells caused by high glucose.

Claudin-15 overexpression inhibits proliferation and promotes apoptosis of Schwann cells in vitro

Our previous experiments have discovered that Claudin-15 was up-regulated in Schwann cells of the distal nerve stumps of rat models of sciatic nerve injury.However,how Claudin-15 affects Schwann cell function is still unknown.This study aimed to identify the effects of Claudin-15 on proliferation and apoptosis of Schwann cells cultured in vitro and explore the underlying mechanisms.Primary Schwann cells were obtained from rats.Claudin-15 in Schwann cells was knocked down using siRNA(siRNA-1 group)compared with the negative control siRNA transfection group(negative control group).Claudin-15 in Schwann cells was overexpressed using pGV230-Claudin-15 plasmid(pGV230-Claudin-15 group).The pGV230 transfection group(pGV230 group)acted as the control of the pGV230-Claudin-15 group.Cell proliferation was analyzed with EdU assay.Cell apoptosis was analyzed with flow cytometric analysis.Cell migration was analyzed with Transwell inserts.The mRNA and protein expressions were analyzed with quantitative polymerase chain reaction assay and western blot assay.The results showed that compared with the negative control group,cell proliferation rate was up-regulated;p-AKT/AKT ratio,apoptotic rate,p-c-Jun/c-Jun ratio,mRNA expression of protein kinase C alpha,Bcl-2 and Bax were down-regulated;and mRNA expression of neurotrophins basic fibroblast growth factor and neurotrophin-3 were increased in the siRNA-1 group.No significant difference was found in cell migration between the negative control and siRNA-1 groups.Compared with the pGV230 group,the cell proliferation rate was down-regulated;apoptotic rate,p-c-Jun/c-Jun ratio and c-Fos protein expression increased;mRNA expression of protein kinase C alpha and Bax decreased;and mRNA expressions of neurotrophins basic fibroblast growth factor and neurotrophin-3 were up-regulated in the pGV230-Claudin-15 group.The above results demonstrated that overexpression of Claudin-15 inhibited Schwann cell proliferation and promoted Schwann cell apoptosis in vitro.Silencing of Claudin-15 had the reverse effect and provided neuroprotective effect.This study was approved by the Experimental Animal Ethics Committee of Jilin University of China(approval No.2016-nsfc001)on March 5,2016.

Transretinoic acid inhibits rats gastric epithelial dysplasia induced by N-methyi-N-nitro-N-nitrosoguanidine:influences on cell apoptosis and expression of its regulatory genes

INTRODUCTIONGastric epithelial dysplasia (GED) hypothetically is a straight-forward concept: dysplastic epithelium replacing the normal gastric epithelium of the stomach [1].In the stomach ,like any other segment of the gut ,it is defined as an unequivocal non-invasive epithelial change[2,3].The observation of gastric dysplasia as a cancerous lesion was recognized over a century ago ,but it is only after the advent of gastroscopy that its clinical significance has been stressed[4-7].

High expression circRALGPS2 in atretic follicle induces chicken granulosa cell apoptosis and autophagy via encoding a new protein

Background The reproductive performance of chickens mainly depends on the development of follicles.Abnor-mal follicle development can lead to decreased reproductive performance and even ovarian disease among chick-ens.Chicken is the only non-human animal with a high incidence of spontaneous ovarian cancer.In recent years,the involvement of circRNAs in follicle development and atresia regulation has been confirmed.Results In the present study,we used healthy and atretic chicken follicles for circRNA RNC-seq.The results showed differential expression of circRALGPS2.It was then confirmed that circRALGPS2 can translate into a protein,named cir-cRALGPS2-212aa,which has IRES activity.Next,we found that circRALGPS2-212aa promotes apoptosis and autophagy in chicken granulosa cells by forming a complex with PARP1 and HMGB1.Conclusions Our results revealed that circRALGPS2 can regulate chicken granulosa cell apoptosis and autophagy through the circRALGPS2-212aa/PARP1/HMGB1 axis.

Killing effect of TNF-related apoptosis inducing ligand regulated by tetracycline on gastric cancer cell line NCI-N87

AIM: To clone the cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) into a tetracycline-regulated gene expression system, the RevTet-On system, transduce expression vectors into a gastric carcinoma cell line-NCI-N87 and examine the effects of controlled expression of TRAIL in vitro on the gastric carcinoma cells. METHODS: The full-length cDNA of TRAIL was inserted into a vector under the control of the tetracycline-responsive element (TRE) to obtain the plasmid pRevTRE-TRAIL, which was transfected into a packaging cell line PT67. In addition, vector pRev-Tet On and pRevTRE were also transfected into PT67 separately. After hygromycin and G418 selection, the viral titer was determined. The medium containing retroviral vectors was collected and used to transduce a gastric carcinoma cell line NCI-N87. The resulting cell line NCI-N87-Tet On TRE-TRAIL and a control cell line, NCI-N87 Tet On-TRE, were established. TRAIL expression in the cell line was induced by incubating cells with doxycycline (Dox), which is a tetracycline analogue. The killing effect on gastric carcinoma cells was analyzed after induction. RESULTS: The recombinant plasmid pRev-TRE-TRAIL was constructed. After hygromycin or G418 selection, the producer cell lines PT67-TRE, PT67-TRE-TRAIL and PT67-Tet On were obtained,with titers of about 10(8)CFU.L(-1). By transducing NCI-N87 cells with retroviral vectors from these cell lines, stable cell lines NCI-N87-Tet-On TRE-TRAIL (NN3T) and control cell line NCI-N87-Tet-On-TRE (NN2T) were established. The growth curves of the selected cell lines were the same with the wild type NCI-N87. When Dox was added, cell death was obvious in the test groups (29%-77%), whereas no difference was observed in control and wild type cell lines. With the addition of a medium from the test group, human leukemia cell line Jurkat was activated till death (83%), indicating the secretion of active TRAIL proteins from the test cells to the medium. CONCLUSION: With the use of the RevTet-On system, a regulated expression system for TRAIL was constructed. Using this system, the selected killing effect of TRAIL on gastric carcinoma cell line NCI-N87 could be observed.

Crosstalk among Oxidative Stress,Autophagy,and Apoptosis in the Protective Effects of Ginsenoside Rb1 on Brain Microvascular Endothelial Cells:A Mixed Computational and Experimental Study

Objective Brain microvascular endothelial cells (BMECs) were found to shift from their usually inactive state to an active state in ischemic stroke (IS) and cause neuronal damage. Ginsenoside Rb1 (GRb1),a component derived from medicinal plants,is known for its pharmacological benefits in IS,but its protective effects on BMECs have yet to be explored. This study aimed to investigate the potential protective effects of GRb1 on BMECs. Methods An in vitro oxygen-glucose deprivation/reperfusion (OGD/R) model was established to mimic ischemia-reperfusion (I/R) injury. Bulk RNA-sequencing data were analyzed by using the Human Autophagy Database and various bioinformatic tools,including gene set enrichment analysis (GSEA),Gene Ontology (GO) classification and enrichment analysis,Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis,protein-protein interaction network analysis,and molecular docking. Experimental validation was also performed to ensure the reliability of our findings. Results Rb1 had a protective effect on BMECs subjected to OGD/R injury. Specifically,GRb1 was found to modulate the interplay between oxidative stress,apoptosis,and autophagy in BMECs. Key targets such as sequestosome 1 (SQSTM1/p62),autophagy related 5 (ATG5),and hypoxia-inducible factor 1-alpha (HIF-1α) were identified,highlighting their potential roles in mediating the protective effects of GRb1 against IS-induced damage. Conclusion GRbl protects BMECs against OGD/R injury by influencing oxidative stress,apoptosis,and autophagy. The identification of SQSTM1/p62,ATG5,and HIF-1α as promising targets further supports the potential of GRb1 as a therapeutic agent for IS,providing a foundation for future research into its mechanisms and applications in IS treatment.

Inhibiting endogenous tissue plasminogen activator enhanced neuronal apoptosis and axonal injury after traumatic brain injury

Tissue plasminogen activator is usually used for the treatment of acute ischemic stroke,but the role of endogenous tissue plasminogen activator in traumatic brain injury has been rarely reported.A rat model of traumatic brain injury was established by weight-drop method.The tissue plasminogen activator inhibitor neuroserpin(5μL,0.25 mg/mL)was injected into the lateral ventricle.Neurological function was assessed by neurological severity score.Neuronal and axonal injuries were assessed by hematoxylin-eosin staining and Bielschowsky silver staining.Protein level of endogenous tissue plasminogen activator was analyzed by western blot assay.Apoptotic marker cleaved caspase-3,neuronal marker neurofilament light chain,astrocyte marker glial fibrillary acidic protein and microglial marker Iba-1 were analyzed by immunohistochemical staining.Apoptotic cell types were detected by immunofluorescence double labeling.Apoptotic cells in the damaged cortex were detected by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP-biotin nick-end labeling staining.Degenerating neurons in the damaged cortex were detected by Fluoro-Jade B staining.Expression of tissue plasminogen activator was increased at 6 hours,and peaked at 3 days after traumatic brain injury.Neuronal apoptosis and axonal injury were detected after traumatic brain injury.Moreover,neuroserpin enhanced neuronal apoptosis,neuronal injury and axonal injury,and activated microglia and astrocytes.Neuroserpin further deteriorated neurobehavioral function in rats with traumatic brain injury.Our findings confirm that inhibition of endogenous tissue plasminogen activator aggravates neuronal apoptosis and axonal injury after traumatic brain injury,and activates microglia and astrocytes.This study was approved by the Biomedical Ethics Committee of Animal Experiments of Shaanxi Province of China in June 2015.

Knockdown of fibrillin-1 suppresses retina-blood barrier dysfunction by inhibiting vascular endothelial apoptosis under diabetic conditions

AIM:To investigate the effects of fibrillin-1(FBN1)deletion on the integrity of retina-blood barrier function and the apoptosis of vascular endothelial cells under diabetic conditions.METHODS:Streptozotocin(STZ)-induced diabetic mice were used to simulate the diabetic conditions of diabetic retinopathy(DR)patients,and FBN1 expression was detected in retinas from STZ-diabetic mice and controls.In the Gene Expression Omnibus(GEO)database,the GSE60436 dataset was selected to analyze FBN1 expressions in fibrovascular membranes from DR patients.Using lentivirus to knock down FBN1 levels,vascular leakage and endothelial barrier integrity were detected by Evans blue vascular permeability assay,fluorescein fundus angiography(FFA)and immunofluorescence labeled with tight junction marker in vivo.High glucose-induced monkey retinal vascular endothelial cells(RF/6A)were used to investigate effects of FBN1 on the cells in vitro.The vascular endothelial barrier integrity and apoptosis were detected by trans-endothelial electrical resistance(TEER)assay and flow cytometry,respectively.RESULTS:FBN1 mRNA expression was increased in retinas of STZ-induced diabetic mice and fibrovascular membranes of DR patients(GSE60436 datasets)using RNA-seq approach.Besides,knocking down of FBN1 by lentivirus intravitreal injection significantly inhibited the vascular leakage compared to STZ-DR group by Evans blue vascular permeability assay and FFA detection.Expressions of tight junction markers in STZ-DR mouse retinas were lower than those in the control group,and knocking down of FBN1 increased the tight junction levels.In vitro,30 mmol/L glucose could significantly inhibit viability of RF/6A cells,and FBN1 mRNA expression was increased under 30 mmol/L glucose stimulation.Down-regulation of FBN1 reduced high glucose(HG)-stimulated retinal microvascular endothelial cell permeability,increased TEER,and inhibited RF/6A cell apoptosis in vitro.CONCLUSION:The expression level of FBN1 increases in retinas and vascular endothelial cells under diabetic conditions.Down-regulation of FBN1 protects the retina of early diabetic rats from retina-blood barrier damage,reduce vascular leakage,cell apoptosis,and maintain vascular endothelial cell barrier function.

Achyranthes bidentata polypeptides prevent apoptosis by inhibiting the glutamate current in cultured hippocampal neurons

Glutamate-induced excitotoxicity plays a critical role in the neurological impairment caused by middle cerebral artery occlusion.Achyranthes bidentata polypeptides have been shown to protect against neurological functional damage caused by middle cerebral artery occlusion,but the underlying neuroprotective mechanisms and the relationship to glutamate-induced excitotoxicity remain unclear.Therefore,in the current study,we investigated the protective effects of Achyranthes bidentata polypeptides against glutamate-induced excitotoxicity in cultured hippocampal neurons.Hippocampal neurons were treated with Mg^2+-free extracellular solution containing glutamate(300μM)for 3 hours as a model of glutamate-mediated excitotoxicity(glutamate group).In the normal group,hippocampal neurons were incubated in Mg^2+-free extracellular solution.In the Achyranthes bidentata polypeptide group,hippocampal neurons were incubated in Mg^2+-free extracellular solution containing glutamate(300μM)and Achyranthes bidentata polypeptide at different concentrations.At 24 hours after exposure to the agents,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Hoechst 33258 staining were used to assess neuronal viability and nuclear m'orphology,respectively.Caspase-3 expression and activity were evaluated using western blot assay and colorimetric enzymatic assay,respectively.At various time points after glutamate treatment,reactive oxygen species in cells were detected by H2 DCF-DA,and mitochondrial membrane potential was detected by rhodamine 123 staining.To examine the effect of Achyranthes bidentata polypeptides on glutamate receptors,electrophysiological recording was used to measure the glutamate-induced inward current in cultured hippocampal neurons.Achyranthes bidentata polypeptide decreased the percentage of apoptotic cells and reduced the changes in caspase-3 expression and activity induced by glutamate.In addition,Achyranthes bidentata polypeptide attenuated the amplitude of the glutamate-induced current.Furthermore,the glutamate-induced increase in intracellular reactive oxygen species and reduction in mitochondrial membrane potential were attenuated by Achyranthes bidentata polypeptide treatment.These findings collectively suggest that Achyranthes bidentata polypeptides exert a neuroprotective effect in cultured hippocampal neurons by suppressing the overactivation of glutamate receptors and inhibiting the caspase-3-dependent mitochondrial apoptotic pathway.All animal studies were approved by the Animal Care and Use Committee,Nantong University,China(approval No.20120216-001)on February 16,2012.

NQO1 Mediates Lenvatinib Resistance by Regulating ROS-induced Apoptosis in Hepatocellular Carcinoma

Objective Hepatocellular carcinoma(HCC)is the third leading cause of cancer-associated death worldwide.As a first-line drug for advanced HCC treatment,lenvatinib faces a significant hurdle due to the development of both intrinsic and acquired resistance among patients,and the underlying mechanism remains largely unknown.The present study aims to identify the pivotal gene responsible for lenvatinib resistance in HCC,explore the potential molecular mechanism,and propose combinatorial therapeutic targets for HCC management.Methods Cell viability and colony formation assays were conducted to evaluate the sensitivity of cells to lenvatinib and dicoumarol.RNA-Seq was used to determine the differences in transcriptome between parental cells and lenvatinib-resistant(LR)cells.The upregulated genes were analyzed by GO and KEGG analyses.Then,qPCR and Western blotting were employed to determine the relative gene expression levels.Afterwards,the intracellular reactive oxygen species(ROS)and apoptosis were detected by flow cytometry.Results PLC-LR and Hep3B-LR were established.There was a total of 116 significantly upregulated genes common to both LR cell lines.The GO and KEGG analyses indicated that these genes were involved in oxidoreductase and dehydrogenase activities,and reactive oxygen species pathways.Notably,NAD(P)H:quinone oxidoreductase 1(NQO1)was highly expressed in LR cells,and was involved in the lenvatinib resistance.The high expression of NQO1 decreased the production of ROS induced by lenvatinib,and subsequently suppressed the apoptosis.The combination of lenvatinib and NQO1 inhibitor,dicoumarol,reversed the resistance of LR cells.Conclusion The high NQO1 expression in HCC cells impedes the lenvatinib-induced apoptosis by regulating the ROS levels,thereby promoting lenvatinib resistance in HCC cells.