Mechanism of Yishen Tongluo Prescription in Inhibiting Endoplasmic Reticulum Stress and Improving Apoptosis of Renal Tubular Epithelial Cells Based on PERK/ATF4/CHOP / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Yishen Tongluo prescription （YSTLP） on apoptosis of renal tubular epithelial cells and explore the mechanism based on endoplasmic reticulum stress pathway of protein kinase R-like endoplasmic reticulum kinase （PERK）/activating transcription factor 4 （ATF4）/transcription factor C/EBP homologous protein （CHOP）. MethodThe db/db mice were randomly divided into model group， valsartan group （10 mg·kg-1）， and low， middle， high-dose YSTLP groups （1， 2.5， 5 g·kg-1）. Samples were collected after eight weeks of drug intervention. In addition， db/m mice in the same litter served as the control group. Human renal tubular epithelial cells （HK-2） were cultured in vitro and divided into the control group， advanced glycated end-product （AGE） group， and AGE + low， middle， and high-dose YSTLP groups （100， 200， 400 mg·L-1）. TdT-mediated dUTP nick end labeling （TUNEL） staining was used to detect the apoptosis rate of HK-2 cells. Methylthiazolyldiphenyl-tetrazolium bromide （MTT） assay was conducted to detect the viability of HK-2 cells. Calcium fluorescence probe staining and luciferase reporter gene method were adopted to detect the luciferase activity of folded protein response element （UPRE） and endoplasmic reticulum stress. Immunohistochemical （IHC） analysis was carried out to measure the protein expressions of phosphorylated PKR （p-PERK）， CHOP， and ATF4. Real-time polymerase chain reaction （Real-time PCR） was used to measure the mRNA expression levels of CHOP and X-box binding protein 1 （XBP1） in mouse kidney and HK-2 cells. Western blot was used to detect the protein expression level of p-PERK， PERK， CHOP， ATF4， B-cell lymphoma-2 （Bcl-2）， Bcl-2 associated X protein （Bax）， and cleaved Caspase-3 in mouse kidney and HK-2 cells. ResultIn the cellular assay， HK-2 cell viability was significantly reduced， and the apoptosis rate was elevated in the AGE group compared with the control group （P<0.01）. The mRNA and protein expression levels of apoptosis-related factor Bcl-2 were significantly reduced （P<0.01）， and those of Bax were significantly increased （P<0.01）. The protein expression level of cleaved Caspase-3 was significantly increased （P<0.01）. Compared with the AGE group， YSTLP administration treatment resulted in elevated cell viability and reduced apoptosis rate （P<0.01）. The mRNA and protein expression levels of Bcl-2 were significantly elevated in a time- and dose-dependent manner （P<0.01）， and those of Bax were significantly reduced in a time- and dose-dependent manner. The protein expression level of cleaved Caspase-3 was significantly reduced in a time- and dose-dependent manner （P<0.01）. The intracellular Ca2+ imbalance and UPRE luciferase fluorescence intensity were increased in the AGE group compared with the control group （P<0.01）. The mRNA levels of endoplasmic reticulum stress-related factors CHOP and XBP1 were significantly increased （P<0.01）， and the protein expression levels of p-PERK， CHOP， and ATF4 were significantly increased （P<0.05）. Compared with the AGE group， YSTLP effectively improved intracellular Ca2+ imbalance in HK-2 cells and decreased UPRE luciferase fluorescence intensity in a dose-dependent manner （P<0.01）. It reduced the mRNA levels of endoplasmic reticulum stress-related factors CHOP and XBP1 （P<0.01） and the protein expression levels of intracellular p-PERK， CHOP， and ATF4 in a dose- and time-dependent manner （P<0.01）. In animal experiments， the protein expression level of Bcl-2 was significantly reduced（P<0.01）， and that of cleaved Caspase-3 and Bax was significantly increased in the model group compared with the control group （P<0.05）. The protein expression level of Bcl-2 was dose-dependently elevated， and that of cleaved Caspase-3 and Bax was dose-dependently decreased in the YSTLP groups compared with the model group （P<0.01）. Compared with the control group， the mRNA expression levels of CHOP and XBP1 were significantly elevated in the model group （P<0.05， P<0.01）， and the protein expression levels of p-PERK， CHOP， and ATF4 were significantly increased （P<0.05）. Compared with the model group， YSTLP significantly decreased the mRNA expression levels of CHOP and XBP1 （P<0.01） and the protein expression levels of p-PERK， CHOP， and ATF4 （P<0.01）. ConclusionYSTLP can effectively inhibit endoplasmic reticulum stress and improve apoptosis of renal tubular epithelial cells， and its mechanism may be related to the regulation of the PERK/AFT4/CHOP pathway.

4E-BP1 counteracts human mesenchymal stem cell senescence via maintaining mitochondrial homeostasis

Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders, the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown. Here, we report that the expression of 4E-BP1 decreases along with the senescence of human mesenchymal stem cells (hMSCs). Genetic inactivation of 4E-BP1 in hMSCs compromises mitochondrial respiration, increases mitochondrial reactive oxygen species (ROS) production, and accelerates cellular senescence. Mechanistically, the absence of 4E-BP1 destabilizes proteins in mitochondrial respiration complexes, especially several key subunits of complex III including UQCRC2. Ectopic expression of 4E-BP1 attenuates mitochondrial abnormalities and alleviates cellular senescence in 4E-BP1-deficient hMSCs as well as in physiologically aged hMSCs. These f indings together demonstrate that 4E-BP1 functions as a geroprotector to mitigate human stem cell senescence and maintain mitochondrial homeostasis, particularly for the mitochondrial respiration complex III, thus providing a new potential target to counteract human stem cell senescence.

Evidence-based practice competency, EBP beliefs and research utilization among Ghanaian nurses: A mediation analysis

PURPOSE@#The disparity between conducting research and putting it into practice has remains a global healthcare issue, with less than 50% of nurses utilizing research. This study aims to determine the level and relationship between Evidence-based practice (EBP) competency, current EBP beliefs and research utilization among nurses.@*DESIGN AND METHOD@#This quantitative study utilized a descriptive-correlational design and mediation analysis. A purposive sampling was used to select six Christian Health Association of Ghana (CHAG) hospitals. Simple random sampling was used to recruit 544 nurses from the six CHAG hospitals. The study utilized mean and standard deviation, Pearson Correlation, ANOVA, and GLS mediation analysis. The researcher obtained ethical approval from the Saint Louis University Research Ethics committee and, the institutional review board of the CHAG.@*FINDINGS@#The results showed that nurses had a low level of EBP competency (M=2.27, SD= 0.255), strong positive EBP beliefs (M=2.58, SD=0.322) and low research utilization (M=2.57, SD=0.300). There was a moderately significant positive relationship between EBP competency and research utilization (r= .431, p= .000), EBP competency and EBP beliefs (r= .327, p= .000) and EBP beliefs and research utilization (r= .306, p= .000). There is no significant difference in terms of EBP competency and research utilization when EBP training attendance was considered. Nurses with 1-2 years of experience had a higher level of EBP competency. Theatre nurses had a higher level of EBP competency, however, emergency nurses had a lower level of research utilization than nurses in the surgical unit. EBP beliefs mediated the relationship (B= 0.0604, z= 3.99, p < .001) between EBP competency and research utilization.@*CONCLUSIONS@#Nurses in CHAG hospitals have a limited ability to implement the EBP process. The respondent perceived the value of EBP in nursing practice to be significant and has the confidence to implement the EBP process. The nurses' respondents use of research in nursing practice is limited due to the organizational barriers in CHAG institutions in Ghana. Based on the findings, it is recommended for nurse administrators and policy makers to prioritize the provision of adequate resources, support, EBP policies and targeted training programs to facilitate a culture of evidence-based practice and research utilization in CHAG institutions. By improving EBP competency and promoting research utilization, nurses can enhance the quality and safety of patient care.

Study of endoplasmic reticulum stress in human dental pulp cells induced by oxygen-glucose deprivation culture in vitro / 口腔疾病防治

Objective@#Oxygen-glucose deprivation (OGD) is used to mimic ischemia in vitro to observe whether endoplasmic reticulum (ER) stress is involved in human dental pulp cells (hDPCs) after OGD and to better understand the regulatory mechanism of hDPCs in ischemia.@*Methods@# hDPCs were cultured in glucose-free DMEM and hypoxia (volume fraction 2% O2) to establish an hDPCs OGD model in vitro, which mimics hDPCs ischemia in vitro. hDPCs were divided into a control group (normal culture) and an experimental group (OGD 0 h, 2 h, 4 h and 8 h groups). After pretreatment with OGD for 0, 2, 4 and 8 h, hDPC viability was measured by methylthiazol tetrazolium (MTT) assay. qRT-PCR was used to detect the mRNA expression of ER stress markers [splicing x-box binding protein1 (sXBP1), activating transcription Factor 4 (ATF4) and C/EBP homologous protein (chop)]. Western blot was used to detect the protein expression of ER stress markers [phosphorylated RNA-activated protein kinase-like ER-resident kinase (p-perk) and phosphorylated eukaryotic initiation factor-2α (p-eIF2α)]. @*Results@#Compared with OGD 0 h group, cell viability of hDPCs decreased when exposed to OGD treatment for 2 h, 4 h and 8 h. Compared with the control group, mRNA expressions of ER stress makers (sXBP1, ATF4 and chop) and the protein expressions of ER stress protein markers (p-perk andp-eIF2α) increased in OGD treatment cells after 4 h were higher in OGD cells. The differences were statistically significant (P<0.05).@*Conclusion@#The results indicate that ER stress response is involved in hDPCs in OGD treatment.

WSB1 regulates c-Myc expression through β-catenin signaling and forms a feedforward circuit

The dysregulation of transcription factors is widely associated with tumorigenesis. As the most well-defined transcription factor in multiple types of cancer, c-Myc can transform cells by transactivating various downstream genes. Given that there is no effective way to directly inhibit c-Myc, c-Myc targeting strategies hold great potential for cancer therapy. In this study, we found that WSB1, which has a highly positive correlation with c-Myc in 10 cancer cell lines and clinical samples, is a direct target gene of c-Myc, and can positively regulate c-Myc expression, which forms a feedforward circuit promoting cancer development. RNA sequencing results from Bel-7402 cells confirmed that WSB1 promoted c-Myc expression through the β-catenin pathway. Mechanistically, WSB1 affected β-catenin destruction complex-PPP2CA assembly and E3 ubiquitin ligase adaptor β-TRCP recruitment, which inhibited the ubiquitination of β-catenin and transactivated c-Myc. Of interest, the effect of WSB1 on c-Myc was independent of its E3 ligase activity. Moreover, overexpressing WSB1 in the Bel-7402 xenograft model could further strengthen the tumor-driven effect of c-Myc overexpression. Thus, our findings revealed a novel mechanism involved in tumorigenesis in which the WSB1/c-Myc feedforward circuit played an essential role, highlighting a potential c-Myc intervention strategy in cancer treatment.

Analysis on Role of mTORC1/4E-BP1 Axis in Idiopathic Pulmonary Fibrosis and Research Progress of Bupleuri Radix on Its Intervention / 中国实验方剂学杂志

Idiopathic pulmonary fibrosis （IPF） is a common， lethal interstitial lung disease characterized by airway remodeling， inflammation， alveolar destruction， and fibrosis. The mammalian target of rapamycin complex 1/4E binding protein 1 （mTORC1/4E-BP1） axis is closely related to the expression of collagen by fibroblasts， and its role in pulmonary fibrosis remains to be further elucidated. Traditional Chinese medicine （TCM） has shown promising efficacy in improving the lung function， exercise capacity， and quality of life in patients with IPF. The theory of "same treatment for different diseases" provides a TCM theoretical basis for the treatment of pulmonary fibrosis with Bupleuri Radix， while the research in western medicine has preliminarily shown that both the formulation and single herb as well as the active ingredients of Bupleuri Radix have good therapeutic effects on pulmonary fibrosis. Therefore， this review will elaborate on the role of the mTORC1/4E-BP1 axis in the pathomechanism of IPF， as well as the research results of the active components of Bupleuri Radix on the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin protein（PI3K/AKT/mTOR） pathway， so as to provide a reference for the treatment and drug development of IPF.

Tubeimoside-1 induces TFEB-dependent lysosomal degradation of PD-L1 and promotes antitumor immunity by targeting mTOR

Programmed cell death ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) cascade is an effective therapeutic target for immune checkpoint blockade (ICB) therapy. Targeting PD-L1/PD-1 axis by small-molecule drug is an attractive approach to enhance antitumor immunity. Using flow cytometry-based assay, we identify tubeimoside-1 (TBM-1) as a promising antitumor immune modulator that negatively regulates PD-L1 level. TBM-1 disrupts PD-1/PD-L1 interaction and enhances the cytotoxicity of T cells toward cancer cells through decreasing the abundance of PD-L1. Furthermore, TBM-1 exerts its antitumor effect in mice bearing Lewis lung carcinoma (LLC) and B16 melanoma tumor xenograft

Dual roles of p62/SQSTM1 in the injury and recovery phases of acetaminophen-induced liver injury in mice

Acetaminophen (APAP) overdose can induce liver injury and is the most frequent cause of acute liver failure in the United States. We investigated the role of p62/SQSTM1 (referred to as p62) in APAP-induced liver injury (AILI) in mice. We found that the hepatic protein levels of p62 dramatically increased at 24 h after APAP treatment, which was inversely correlated with the hepatic levels of APAP-adducts. APAP also activated mTOR at 24 h, which is associated with increased cell proliferation. In contrast, p62 knockout (KO) mice showed increased hepatic levels of APAP-adducts detected by a specific antibody using Western blot analysis but decreased mTOR activation and cell proliferation with aggravated liver injury at 24 h after APAP treatment. Surprisingly, p62 KO mice recovered from AILI whereas the wild-type mice still sustained liver injury at 48 h. We found increased number of infiltrated macrophages in p62 KO mice that were accompanied with decreased hepatic von Willebrand factor (VWF) and platelet aggregation, which are associated with increased cell proliferation and improved liver injury at 48 h after APAP treatment. Our data indicate that p62 inhibits the late injury phase of AILI by increasing autophagic selective removal of APAP-adducts and mitochondria but impairs the recovery phase of AILI likely by enhancing hepatic blood coagulation.

Inhibition of LIM kinase reduces contraction and proliferation in bladder smooth muscle

Overactive bladder (OAB) is the most bothersome symptom in lower urinary tract symptoms (LUTS). Current pharmacologic treatment aims to inhibit detrusor contraction; however, shows unsatisfied efficacy and high discontinuation rate. LIM kinases (LIMKs) promote smooth muscle contraction in the prostate; however, their function in the bladder smooth muscle remains unclear. Here, we studied effects of the LIMK inhibitors on bladder smooth muscle contraction and proliferation both

Polyphyllin I promotes cell death via suppressing UPR-mediated CHOP ubiquitination and degradation in non-small cell lung cancer / 中国天然药物

Polyphyllin I (PPI) purified from Polyphyllarhizomes displays puissant cytotoxicity in many kinds of cancers. Several researches investigated its anti-cancer activity. But novel mechanisms are still worth investigation. This study aimed to explore PPI-induced endoplasmic reticulum (ER) stress as well as the underlying mechanism in non-small cell lung cancer (NSCLC). Cell viability or colony-forming was detected by MTT or crystal violet respectively. Cell cycle, apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential were assessed by flow cytometry. Gene and protein levels were evaluated by qRT-PCR and immunoblotting respectively. Protein interaction was determined by immunoprecipitation or immunofluorescence assay. Gene overexpression or silencing was carried out by transient transfection with plasmids or small interfering RNAs. The Cancer Genome Atlas (TCGA) database was used for Gene Set Enrichment Analysis (GSEA), survival analysis, gene expression statistics or pathway enrichment assay. PPI inhibited the propagation of NSCLC cells, increased non-viable apoptotic cells, arrested cell cycle at G2/M phase, induced ROS levels but failed to decrease mitochondrial membrane potential. High levels of GRP78 indicates poor prognosis in NSCLC patients. PPI selectively suppressed unfolded protein response (UPR)-induced GRP78 expression, subsequently protected CHOP from GRP78-mediated ubiquitination and degradation. We demonstrated that the natural product PPI, obtained from traditional herbal medicine, deserves for further study as a valuable candidate for lead compound in the chemotherapy of NSCLC.

Role and Mechanism of miRNA-155 in Development, Progression and Lung Metastasis of Osteosarcoma / 肿瘤防治研究

Objective To investigate the role of miR-155 in the development and lung metastasis of osteosarcoma, and to explore its target proteins and related mechanisms. Methods We detected differential miR-155 expression in osteosarcoma and its lung metastasis process through relevant database analysis combined with qPCR detection of clinical tissue and cell samples. iTRAQ quantitative proteomics was used to screen the target protein of miR-155 in osteosarcoma and its lung metastasis. The selected miR-155 target protein was verified by Western blot in clinical tissue and cell samples. Results miR-155 expression was significantly higher in osteosarcoma tissue and lung metastatic tumor tissue than that in the control group. Compared with human normal osteoblasts, miR-155 expression in human osteosarcoma cell line was also significantly increased. A total of 3714 proteins were obtained by iTRAQ assay, and 253 differentially-expressed proteins were screened out, 144 of which were up-regulated and 109 were down-regulated. The prediction analysis and experiment verified that C/EBP β was a potential target protein of miR-155. Conclusion miR-155 expression is significantly increased in osteosarcoma and its lung metastasis process, and C/EBP β is a potential target of miR-155.

Extent of EBP process implementation of PT Clinicians in PLM-affiliated institutions

Background@#Evidence Based Practice (EBP) is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of an individual patient. It integrates clinical expertise, best evidences and patient's values through the implementation of 5 EBP processes: Ask, Acquire, Appraise, Apply and Assess which improve both patient care and clinical practice every time the cycle completes its turn. Despite of its effectiveness, implementation of EBP is a challenge. Variations and inconsistencies in the implementation of the EBP processes were found due to different factors and barriers. Philippines shares the same challenges and barriers in the implementation of EBP process but no local study has been found on the extent of implementation of EBP processes among Physical Therapist. @*Objectives@#This study determines the extent of the EBP processes implemented by PT clinicians in PLMaffiliated institutions. @*Methodology@#This is a descriptive cross-sectional survey that made use of a developed and validated questionnaire which collected the data on demographic profile: age, gender and year graduated, highest educational attainment and the extent of EBP process implementation of Physical Therapist in PLM – affiliation centers.@*Results@#Ninety-three PTs responded in the study. 89.2% (n=83) has BSPT as their highest educational attainment. 2.2% (n=2) has Masters while 3.2% (n=3) has Doctorate in Physical Therapy. EBP is implemented by respondents. Asking clinical questions was implemented at a high extent (composite mean = 2.88) while searching for evidence (2.17), critical appraisal (2.25), use or integration of research (2.46), evaluation of outcomes (2.1) were implemented at a low extent. @*Conclusion@#Although, EBP processes has been implemented in the local university's affiliation, majority of the processes were implemented at a low extent except for asking clinical questions, which was implemented at a high extent. Greater efforts on addressing common barriers have been recommended to be able to fully implement EBP practice.

Effects of arsenite and MPST over-expressin on GRP78/CHOP endoplasmic reticulum stress pathway in SH-SY5Y cells / 中国药理学通报

Aim To investigate whether endoplasmic reticulum stress is involved in the neurotoxicity of sodi¬um arsenite and clarify whether over-expression of 3-mercaptopyruvate sulfurtransferase (MPST) regulates endoplasmic reticulum stress induced by arsenic. Methods The SH-SY5Y cell line stably expressing the exogenous MPST gene was obtained by constructing the lentiviral vector of MPST gene. The SH-SY5Y cells were randomly divided into six groups, the SR-MPST over-expression group stably expressing the exogenous MPST gene, SH-PEB control group transfected with empty vector, the arsenite treatment group ( NaAs02 group ), TUDC A treatment group ( blocker of endoplasmic reticulum stress ) and TUDC A + NaAs02 group. Western blot was used to examine the protein expression of GRP78 and CHOP after different treatment. Results Although MPST overexpression had no significant effects on the expression of GRP78 and CHOP proteins, NaAs02 could significantly increased the protein levels of GRP78 and CHOP ( P < 0. 01 ) and the up-regulation of GRP78 and CHOP proteins caused by NaAs02 could be blocked by the treatment of TUDC A. In addition, the inhibition by MPST overexpression on the arsenic-induced increase of GRP78 and CHOP proteins (P <0. 01 ) could also be reversed by the TUDC A treatment significantly. Conclusions The GRP78/ CHOP endoplasmic reticulum stress pathway is involved in the neurotoxic damage induced by arsenic; MPST overexpression may decrease arsenic-induced endoplasmic reticulum stress.

Trdmt1 3'-untranslated region functions as a competing endogenous RNA in leukemia HL-60 cell differentiation

Severe blockage in myeloid differentiation is the hallmark of acute myeloid leukemia (AML). Trdmt1 plays an important role in hematopoiesis. However, little is known about the function of Trdmt1 in AML cell differentiation. In the present study, Trdmt1 was up-regulated and miR-181a was down-regulated significantly during human leukemia HL-60 cell differentiation after TAT-CT3 fusion protein treatment. Accordingly, miR-181a overexpression in HL-60 cells inhibited granulocytic maturation. In addition, our "rescue" assay demonstrated that Trdmt1 3′-untranslated region promoted myeloid differentiation of HL-60 cells by sequestering miR-181a and up-regulating C/EBPα (a critical factor for normal myelopoiesis) via its competing endogenous RNA (ceRNA) activity on miR-181a. These findings revealed an unrecognized role of Trdmt1 as a potential ceRNA for therapeutic targets in AML.

Accelerating research evidence translation through dyadic engagement: A developing model for evidence-based practice implementation

@#Evidence-based practice (EBP) has been regarded as the gold standard of clinical practice in the health profession. However, even though the importance of EBP is well documented in the nursing literature, in developing countries, its implementation remains a challenge. In addition to individual and organizational barriers to EBP implementation, the existence of the academician-clinician divide is a critical concern. This seeming disconnect has significantly hampered the translation of knowledge into practice. Hence, collaborative dyadic engagements between the academician and clinicians have to be nurtured. The Accelerating Research evidence translation through Dyadic Engagement (ARDE) Model, a pragmatic way of facilitating the enculturation of EBP, is proposed and collaborative efforts in solving clinically relevant nursing issues will pave the way for EBP to become an integral part of clinical practice.

Disturbed Yin-Yang balance: stress increases the susceptibility to primary and recurrent infections of herpes simplex virus type 1

Herpes simplex virus type 1 (HSV-1), a neurotropic herpes virus, is able to establish a lifelong latent infection in the human host. Following primary replication in mucosal epithelial cells, the virus can enter sensory neurons innervating peripheral tissues nerve termini. The viral genome is then transported to the nucleus where it can be maintained without producing infectious progeny, and thus latency is established in the cell. Yin-Yang balance is an essential concept in traditional Chinese medicine (TCM) theory. Yin represents stable and inhibitory factors, and Yang represents the active and aggressive factors. When the organism is exposed to stress, especially psychological stress caused by emotional stimulation, the Yin-Yang balance is disturbed and the virus can re-engage in productive replication, resulting in recurrent diseases. Therefore, a better understanding of the stress-induced susceptibility to HSV-1 primary infection and reactivation is needed and will provide helpful insights into the effective control and treatment of HSV-1. Here we reviewed the recent advances in the studies of HSV-1 susceptibility, latency and reactivation. We included mechanisms involved in primary infection and the regulation of latency and described how stress-induced changes increase the susceptibility to primary and recurrent infections.

RICTOR/mTORC2 affects tumorigenesis and therapeutic efficacy of mTOR inhibitors in esophageal squamous cell carcinoma

Dysregulation of mTORC1/mTORC2 pathway is observed in many cancers and mTORC1 inhibitors have been used clinically in many tumor types; however, the mechanism of mTORC2 in tumorigenesis is still obscure. Here, we mainly explored the potential role of mTORC2 in esophageal squamous cell carcinoma (ESCC) and its effects on the sensitivity of cells to mTOR inhibitors. We demonstrated that RICTOR, the key factor of mTORC2, and p-AKT (Ser473) were excessively activated in ESCC and their overexpression is related to lymph node metastasis and the tumor-node-metastasis (TNM) phase of ESCC patients. Furthermore, we found that mTORC1/ mTORC2 inhibitor PP242 exhibited more efficacious anti-proliferative effect on ESCC cells than mTORC1 inhibitor RAD001 due to RAD001-triggered feedback activation of AKT signal. Another, we demonstrated that down-regulating expression of RICTOR in ECa109 and EC9706 cells inhibited proliferation and migration as well as induced cell cycle arrest and apoptosis. Noteworthy, knocking-down stably RICTOR significantly suppresses RAD001-induced feedback activation of AKT/PRAS40 signaling, and enhances inhibition efficacy of PP242 on the phosphorylation of AKT and PRAS40, thus potentiates the antitumor effect of RAD001 and PP242 both and . Our findings highlight that selective targeting mTORC2 could be a promising therapeutic strategy for future treatment of ESCC.

Endoplasmic reticulum stress-induced apoptosis up-regulation of DR5 via a CHOP-dependent mechanism in HSC-T6 cells / 中国临床药理学与治疗学

AIM: To investigate the inhibitory effects of endoplasmic reticulum stress(ERS) and TRAIL on hepatic stellate cells in vitro and how their interaction affect the apoptosis of hepatic stellate cells. METHODS: Take thapsigargin (TG) as the endoplasmic reticulum stress-inducing agents, ursodeoxycholic acid (UDCA) for the endoplasmic reticulum stress inhibitors, SP600125 as a c-Jun N-terminal kinase(JNK) inhibitor, HSC-T6 cells were divided into normal control group, DMSO group, TRAIL group, TG group, UDCA group, siCHOP group and SP600125 group. The apoptosis rate of HSC-T6 cell was detected by flow cytometry. Small interference RNA was applied to silence C/EBP homologous protein(CHOP) gene. The protein expression levels of Caspase-8 were detected by immunohistochemistry method. The ERS marker protein CHOP and TRAIL receptor DR5 expression levels were determined by RT-PCR and Western blot. RESULTS:TG (1 μmol/L, 2 μmol/L, 4 μmol/L, 8 μmol/L, 16 μmol/L) increased cell apoptosis rate of HSC-T6. RT-PCR and Western blot showed that the endoplasmic reticulum stress protein marker CHOP could induce the upregulation of TRAIL receptor DR5 and Caspase-8. Moreover, siCHOP and the JNK inhibitor SP600125 could reduce the expression of DR5 and Caspase-8 in HSC cells. CONCLUSION: These results indicated that CHOP and JNK may be a potential factor regulating DR5 expression, and play an important role in the process of apoptosis of hepatic stellate cells.

Saikosaponin-d simultaneously induces apoptotic and paraptosis-like cell death in hepatoma cells / 西安交通大学学报(医学版)

Objective: To investigate the cell death-inducing effect of saikosaponin-d (SSD) on human hepatoma Hep3B cells and its potential mechanism. Methods: Hepatoma Hep3B cells were divided into five groups: blank control group, DMSO (vehicle) group, and three SSD treatment groups treated with various doses of SSD (5, 10, and 15 μmol/L). MTT assay was used to evaluate cell viability. Flow cytometer was employed to quantitatively detect the percentage of dead cells after Annexin V-FITC/PI double staining. Apoptosis was detected morphologically after Hoechst 33258 staining. The activity of caspase-3 apoptotic protease was determined by spectrophotometry. Cell morphologic changes were observed with an inverted microscope. Western blotting and Real-time PCR were employed to evaluate the expression levels of C/EBP homology (CHOP) protein and mRNA, respectively. Results: MTT assay showed that SSD inhibited the viability of human hepatoma Hep3B cells in concentration- and time-dependent manners. Sinomenine hydrochloride induced the death of Hep3B cells in a concentration-dependent manner indicated by flow cytometry. After staining with Hoechst 33258, the nuclei of SSD-treated cells showed nucleosomal agglutination, nucleosomal shrinkage and fragmentation under the fluorescence microscope, which are the characteristics of apoptotic cells. SSD significantly activated the key apoptotic executor caspase-3. The occurrence of paraptosis, characterized by extensive cytoplasmic vacuoles, was observed in SSD-treated cells under an inverted microscope. The pretreatment of a pancaspase inhibitor Z-VAD-FMK completely inhibited caspase-3 activity triggered by SSD, but only partially suppressed cell death and could not reduce the cytoplasmic vacuolation in SSD-treated cells. The protein and mRNA expressions of CHOP, a stress-inducible molecule, were upregulated by SSD, which could not be inhibited by Z-VAD-FMK. Conclusion: SSD can simultaneously induce caspase-dependent apoptosis and caspase-independent paraptosis in human hepatoma Hep3B cells. The upregulated expression of CHOP may be the mechanism involved in SSD-induced paraptosis.

Investigating the role of Ebp1 in Chandipura virus infection

ErbB-3 binding protein 1 (Ebp1) is a host protein which binds ErbB-3 receptor to induce signalling events for cell growthregulation. In addition, Ebp1 also interacts with ribonucleoprotein complexes. In recent times, Ebp1 was found to play anantagonistic role in viral infections caused by Influenza and Rinderpest viruses. In our present work we have tried tounderstand the role of Ebp1 in Chandipura virus (CHPV) infection. We have observed an induction in Ebp1 expressionupon CHPV infection similar to other viruses. However, unlike other viruses an overexpressed Ebp1 only reduces viralprotein expression, but does not affect its progeny formation. Additionally, this effect is being carried out in an indirectmanner, as there is no interaction between Ebp1 and viral proteins. This is despite Ebp1’s presence in viral inclusion bodies.