Overexpression of secretory clusterin (sCLU) induces chemotherapy resistance in human gastric cancer cells by targeting miR-195-5p

Recent focus has turned to secretory clusterin (sCLU) as a key contributor to chemoresistance of anticancer agents, but the role of sCLU on chemotherapy drug response to gastric cancer cells is not fully understood. Previous research found that sCLU was overexpressed in the induced multidrug-resistant MGC-803/5-FU cell line, suggesting that sCLU upregulation was closely related to chemoresistance to anticancer agents. In the present study, we aimed to clarify the role and mechanisms of sCLU in regulating the chemoresistance of gastric cancer cells. Cell apoptosis and cell viability were evaluated by annexin V/propidium iodide staining and CCK8. Expression of sCLU and miR-195-5P was detected using quantitative RT-PCR assays. The expression of sCLU in gastric cancer tissues was detected by RT-PCR assays. Upregulating or downregulating sCLU or miR-195-5P in gastric cancer cells was used to evaluate the mechanisms of chemoresistance. We found that sCLU was significantly elevated in the MGC-803/5-FU and SGC-7901 cells, and the downregulating sCLU sensitized MGC-803/5-FU and SGC-7901 cells to cisplatin and Docetaxel by upregulation of miR-195-5P. Upregulating sCLU in MGC-803 and HGC-27 cells was resistant to cisplatin and Docetaxel by downregulating miR-195-5p. Targeting miR-195-5P reduced the sensitivity of MGC-803 cells to 5-FU, and miR-195-5P overexpression enhanced the sensitivity of MGC-803/5-FU cells to 5-FU. The overexpression of sCLU in gastric cancer tissues was associated with chemoresistance. Our findings suggest that overexpression of sCLU induced chemoresistance in gastric cancer cells by downregulating miR-195-5p, thus providing a potential target for the development of agents that targeting sCLU for gastric cancer therapy.

Establishment of a human MYH6 compound heterozygous knockout hESC line to model cardiomyopathy and congenital heart defects by CRISPR/Cas9 system

MYH6 encodes the alpha heavy chain subunit of cardiac myosin. Mutations in MYH6 cause cardiomyopathy and congenital heart defects. However, due to embryonic lethality in MYH6 knockout mice, the precise roles of MYH6 in cardiomyopathy, congenital heart defects and development process remain largely unknown. In this study, we generated a human MYH6 compound heterozygous knockout hESC line using CRISPR/Cas9 technology. The establishment cell line WAe009-A-46 carried a compound heterozygous 2 bp deletion/7 bp deletion in MYH6, expressed pluripotency markers, showed a normal karyotype and exhibited capability to differentiate into the three germ layers in vitro. MYH6 protein was not detectable in WAe009-A-46 line. This cell line provides a useful tool for studying the role of MYH6 in cardiomyopathy and congenital heart defects.

Upregulated miRNA-543 promotes the proliferation and migration of gastric carcinoma by downregulating KLF6

This study aims to uncover the potential function of MicroRNA-543 (miRNA-543) in the pathogenesis of gastric carcinoma and the possible mechanism. MiRNA-543 levels in gastric carcinoma tissues and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Regulatory effects of miRNA-543 on proliferative and migratory abilities of AGS and MKN45 cells were assessed. The downstream target of miRNA-543 was predicted by online bioinformatics and verified by dual-luciferase reporter gene assay. At last, rescue experiments were carried out to uncover the interaction between miRNA-543 and Krüppel-like factor 6 (KLF6) in the progression of gastric carcinoma. MiRNA-543 was upregulated in gastric carcinoma tissues and cell lines. Particularly, gastric carcinoma patients with advanced stage or positive metastasis expressed higher abundance of miRNA-543. Overexpression of miRNA-543 promoted proliferative ability in gastric carcinoma, manifesting as increased viability, EdU-positive ratio and migratory cell number in AGS and MKN45 cells. KLF6 was proved to be the downstream target of miRNA-543. Both mRNA and protein levels of KLF6 were negatively regulated by miRNA-543 in gastric carcinoma cells. Silence of KLF6 was able to reverse the regulatory effects of miRNA-543 inhibitor on proliferative and migratory abilities in gastric carcinoma. MiRNA-543 is highly expressed in gastric carcinoma. It accelerates gastric carcinoma cells to proliferate and migrate by negatively regulating KLF6 level.

Long-term statin use before primary percutaneous coronary intervention improves treatment outcomes of acute myocardial infarction

Numerous studies have reported that high-dose statin loading therapy prior to primary percutaneous coronary intervention (PPCI) improves the clinical outcomes of patients following acute myocardial infarction (AMI). However, little is known about the effects of long-term statin use prior to PPCI on such outcomes. Therefore, the aim of the present analysis was to clarify the effects of long-term statin use before PPCI on the treatment outcomes of patients following AMI. The records of 213 patients who had AMI and met the inclusion criteria were retrospectively reviewed. Patients were divided into two groups: A control group (n=178) who had received no statin pretreatment before AMI onset, and a statin group (n=35) who had received statin treatment for ≥1 month before AMI onset. All patients received a standard treatment regimen for the secondary prevention of coronary artery disease after PPCI. Baseline clinical variables, details of the PPCI procedure and clinical outcomes within 3 months after treatment were reviewed. Patients in the statin group were significantly older than those in the control group (P=0.003). Compared with the control group, there was a greater proportion of patients with hyperlipidemia and previous angina pectoris in the statin group. There were no differences in the use of other drugs (aspirin, β-blockers and angiotensin-converting enzyme inhibitors) prior to PPCI between the two groups. The corrected TIMI frame count (cTFC) was significantly lower in the statin group than in the control group (24.1±12.8 vs. 29.4±14.3, respectively; P=0.043). Multivariable linear regression analysis showed that long-term statin use before AMI was a significant predictor of cTFC after PPCI (P=0.012). Furthermore, the incidence of major adverse cardiac events within 3 months after PPCI was higher in the control group than in the statin group (16.8 vs. 2.9%, respectively; P=0.032). Logistic regression analysis showed that previous statin use was associated with the incidence of major adverse cardiac events within 3 months after treatment (P=0.012). The results of the present study demonstrate that long-term statin use prior to PPCI improved treatment outcomes after AMI in actual clinical practice.

[Correlation between polymorphism of angiotensin-converting enzyme gene and the lower extremity atherosclerosis in type 2 diabetes mellitus patients]

Objective: To explore the correlation between polymorphism of the angiotensin-converting enzyme (ACE) gene and lower extremity atherosclerosis (LEA) in type 2 diabetes mellitus (T2DM) patients. Methods: A total of 380 patients diagnosed with T2DM in Department of Endocrinology from June 2015 to March 2016 were enrolled and divided into two groups: group A had no LEA (n=120) and group B had LEA(n=260). Color doppler ultrasound was used to detect the vascular lesions of the patients. For all patients in groups A and B, the polymerase chain reaction (PCR) was applied to determined the insertion/deletion polymorphism in intron 16 of the ACE gene of the patients. Then the blood pressure, blood lipid, glycated hemoglobin, and renal function were measured. Furthermore, the measured data was compared between the two groups. Multivariate logistic regression analysis was used to analyze the independent risk factors for LEA. Results: There was no significant statistical difference in age, sex, smoking and disease course between the two groups. The frequencies of DD genotype and D allele in the ACE gene of group B were much higher than those in group A. More specifically, DD genotype frequency was 18.8% in group B and 9.2% in group A, D allele frequency was 36.8% in group B and 29.2% in group A (all P<0.05). Multivariate logistic regression analysis showed that DD genotype in ACE gene (OR=2.744, 95% CI: 1.326-5.682), systolic blood pressure (OR=1.725, 95% CI: 1.072-2.778), total cholesterol (OR=3.785, 95% CI: 1.796-7.978), and glycated hemoglobin (OR=2.612, 95% CI: 1.602-4.258) were risk factors for LEA in T2DM patients. Conclusions: ACE gene insertion/deletion polymorphism was associated with the incidence of LEA in T2DM patients. DD genotype of the ACE gene may be a genetic risk factor for T2DM patients with concurrent atherosclerosis.

Effect of intracoronary nitroprusside injection on flow recovery during primary PCI in acute STEMI patients

BACKGROUND

The no/slow reflow phenomenon during primary percutaneous coronary intervention (PPCI) causes the destruction of the coronary microcirculation and further myocardial damage. Some studies have shown that intracoronary nitroprusside infusion is a safe and effective method for managing the no/slow reflow phenomenon. However, it is uncertain whether the injection of nitroprusside at a specific time point during PPCI can most effectively prevent no-reflow. In this study, we investigated the effect of the timing of an intracoronary nitroprusside injection on flow recovery during PPCI in patients with ST elevation acute myocardial infarction (STEMI).

METHODS

One hundred twenty consecutive patients with STEMI who underwent PPCI were enrolled in the study. Patients who fulfilled the eligibility criteria were randomly allocated to three groups: control group (N.=40) received no nitroprusside before they completed PCI; the second group (N.=40) received nitroprusside before balloon dilatation; and the third group (N.=40) received nitroprusside after each balloon dilatation and before contrast agent refilling. The baseline clinical variables and the details of the PCI procedure were collected. The thrombolysis in myocardial infarction (TIMI) flow grades and the corrected TIMI frame count (cTFC) were evaluated immediately after stent implantation was completed.

RESULTS

There were no significant differences in the baseline characteristics, antithrombotic drugs given before PCI, and details of the PCI procedure among the three groups (P>0.05). The incidence of TIMI grade 3 after PCI was significantly higher in the nitroprusside group than in the control group (P=0.025), whereas cTFC was significantly lower in the nitroprusside group (26.6±15.2) than in the control group (38.1±21.3, P=0.001). The incidence of TIMI grade 3 after PCI was significantly higher in the third group than in the second group (P=0.045), and cTFC was significantly lower in the third group (21.5±9.5) than in the second group (31.2±18.3, P=0.002). Multivariable linear regression analyses showed that the intracoronary nitroprusside injection time was a significant predictor of cTFC after PCI.

CONCLUSIONS

These data suggest that the intracoronary injection of nitroprusside significantly reduced the incidence of no/slow reflow during PPCI. The intracoronary injection of nitroprusside most effectively prevented the no/slow reflow phenomenon when administered between balloon dilatation and contrast agent refilling during PPCI.

[Identification of the metabolites of Dingzhi Xiaowan extract in depressive rat plasma, urine, feces and bile after intragastric administration]

Dingzhi Xiaowan is a widely used traditional Chinese medicine in treating depression, which is a similar formula of Kaixinsan. In this research, a rapid ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS(E)) method was established to analyze the metabolites of Dingzhi Xiaowan in depressive model rat plasma, bile, urine and feces. After we established Chronic unpredictable mild stress (CUMS) model rats and orally administrated Dingzhi Xiaowan, rat plasma, bile, urine and feces samples were collected and prepared. Using Waters Cortects UPLC C18 column (2.1 mm x 50 mm, 1.6 μm), acetonitrile-0.1% formic acid mobile phase gradient, these samples were analyzed and 33 metabolites of nine bioactive compounds were detected and tentatively identified by Metabolynx. Among the 33 metabolites, three metabolites were identified from plasma sample, three came from bile sample, and 27 metabolites were identified from urine and feces samples. This approach provided a rapid method for characterizing the metabolites of Dingzhi Xiaowan and gave the truly active structures and the action mechanism of their antidepressant effects.

Effect of Tenuifoliside A isolated from Polygala tenuifolia on the ERK and PI3K pathways in C6 glioma cells

Tenuifoliside A (TFSA) is a bioactive oligosaccharide ester component of Polygala tenuifolia Wild, a traditional Chinese medicine which was used to manage mental disorders effectively. The neuroprotective and anti-apoptotic effects of TFSA have been demonstrated in our previous studies. The present work was designed to study the molecular mechanism of TFSA on promoting the viability of rat glioma cells C6. We exposed C6 cells to TFSA (or combined with ERK, PI3K and TrkB inhibitors) to examine the effects of TFSA on the cell viability and the expression and phosphorylation of key proteins in the ERK and PI3K signaling pathway. TFSA increased levels of phospho-ERK and phospho-Akt, enhanced release of BDNF, which were blocked by ERK and PI3K inhibitors, respectively (U0126 and LY294002). Moreover, the TFSA caused the enhanced phosphorylation of cyclic AMP response element binding protein (CREB) at Ser133 site, the effect was revoked by U0126, LY294002 and K252a. Furthermore, when C6 cells were pretreated with K252a, a TrkB antagonist, known to significantly inhibit the activity of brain-derived neurotrophic factor (BDNF), blocked the levels of phospho-ERK, phospho-Akt and phosphor-CREB. Taking these results together, we suggested the neuroprotection of TFSA might be mediated through BDNF/TrkB-ERK/PI3K-CREB signaling pathway in C6 glioma cells.

[Study on chemical constituents of rhizome of Ardisia gigantifolia]

OBJECTIVE

To study the chemical constituents of the dried rhizome of Ardisia gigantifolia.

METHOD

The 60% ethanol extract was extracted with EtOAc, and then separated and purified by column chromatography using silica gel and preparative HPLC. Their structures were identified on the basis of spectral analysis and physico-chemical properties.

RESULT

Nine compounds were isolated and identified as 11-O-galloylbergenin (1), 11-O-syringylbergenin (2), 11-O-protocatechuoylbergenin (3), 4-O-galloylbergenin (4), 11 -O-vanilloylbergenin (5), (-) -epicatechin-3-gallate (6), stigmasterol-3-O-beta-D-glucopyranoside (7), (-) -4'-hydroxy-3-methoxyphenyl-beta-D-[6-O-(4"-hydroxy-3", 5"-dimethoxybenzoyl)] -glucopyranoside (8), and beta-sitosterol (9).

CONCLUSION

Compounds 3, 4 and 7 were isolsted from the genus Ardisia for the first time, while compounds 1, 2, 5 and 6 were isolated from this plant for the first time.

[Study of immunogenicity of chlorogenic acid-BSA with different number of CGA]

OBJECTIVE

To investigate the immunogenicity of chlorogenic acid-BSA(CGA-BSA) and the foundation for the allergization of CGA-BSA.

METHOD

The CGA-BSA with different number of CGA was synthesized to allergize the BALB/c mice and SD rats to get antiserum. The level of IgE and histamine was analyzed by ELISA, and the passive cutaneous anaphylaxis (PCA) test was carried to analyze the antibody titer.

RESULT

When the coupling rate of CGA-BSA is 20, the highest IgE and histamine level in BALB/c mice and the antibody titer in PCA are the highest.

CONCLUSION

It has better immunogenicity when the coupling rate of CGA-BSA is between 10 to 20, while the CGA-BSA 20 with the best immunogenicity.

[Synthesis and optimize reaction conditions of chlorogenic acid artificial antigen]

OBJECTIVE

To synthesize artificial antigen of the chlorogenic acid (CGA), a constituent in Traditional Chinese Medicine, then optimize the reaction conditions, so that to supply the basis in material and technique for study on Chinese medicine injection of adverse reactions in-depth.

METHOD

The complete antigen of chlorogenic acid (CGA-BSA) was synthesized by CGA coupled to carrier protein bovine serum albumi (BSA) using carbodiimide method. We used the orthogonal design test to optimize reaction conditions and used the MALDI-TOF-MS and UV motheds to determine the coupling rate of the CGA-BSA.

RESULT

The coupling rate were 20 and 18.8, counting by MALDI-TOF-MS and UV, respectively; while the best reaction conditions were NHS: CGA, EDC: CGA, CGA: BSA were 4: 1, 1: 1, 200: 1, respectively, with the pH 9.

CONCLUSION

The complete antigen is preparated successfully. Which supplied the basis to advanced study of correlation.

[Effect of Acorus tatarinowii schott on ultrastructure and permeability of blood-brain barrier]

OBJECTIVE

To explore the influence of Acorus tatarinowii schott on ultrastructure and permeability of BBB.

METHOD

The ultrastructure and permeability of BBB on rats with A. tatarinowii by electron microscope were observed. The even's blue (EB) and sodium phenytoin in brain was determined by UV and HPLC-MS.

RESULT

After give A. tatarinowii, tight junctions of the endothelial cell opened in cotex, and the concentration of EB and sodium phenytoin in brain are significant increased.

CONCLUSION

A. tatarinowii can increase the permeability of BBB, and show its 'Kaiqiao' effect.