The abnormal expression level of microRNA in epithelial-mesenchymal transition of peritoneal mesothelial cells induced by high glucose

OBJECTIVE

To determine the expression level of the microRNA in the process of epithelial-mesenchymal transition (EMT) of the peritoneal mesothelial cells (PMCs) induced by high glucose.

MATERIALS AND METHODS

The PMCs were cultured using M199 medium with 10% fetal bovine serum, and the EMT was induced by D-glucose stimulation. Epithelial-mesenchymal transition was determined by changes in cell morphology and the expression levels of the EMT marker genes. Changes in cell morphology were observed by inverted microscope, and the expression levels of the EMT marker genes were determined by real-time PCR. The expression levels of the microRNA were detected by real-time PCR with microRNA-specific stem-loop structure primer.

RESULTS

The PMCs changed to fusiformis following a high-glucose medium stimulated for 48 hours, and the EMT marker genes changed significantly, such as the decrease of E-cadherin and an increase of Vimentin (p < 0.01). These results proved the EMT had been induced by high-glucose. Applying real-time PCR with microRNA-specific stem-loop structure primer, miR-193a increased notably (p < 0.01), and miR-15a and let-7e decreased (p < 0.01), while miR-16 and miR-21 had no significant changes (p > 0.05). Most importantly, the increase of miR-193a was correlated with stimulus duration.

CONCLUSIONS

MicroRNA with abnormal expression levels have a primary role in regulating the EMT of PMCs induced by high glucose.

Inhibition of autophagy strengthens celastrol-induced apoptosis in human pancreatic cancer in vitro and in vivo models

OBJECTIVES

Celastrol, a quinone methide triterpenoid, could induce apoptosis in pancreatic cancer cells. The purpose of this study is to determine whether there is protective autophagy after celastrol treatment in pancreatic cancer cells and the synergistic effects of celastrol and 3-MA in vitro and in vivo.

METHODS

The cells viability was measured using MTT assays. Degree of apoptosis and amount of autophagic vacuoles were measured by flow cytometry. Immunofluorescence was adapted to monitor the localization of autophagic protein LC3-II. Expression of LC3-II, cleaved caspase-3, Bax and bcl-2 was detected by immunoblot. Autophagosomes were observed by electron microscopy. The synergistic effect of celastrol and 3- MA in vivo was studied in the MiaPaCa-2 xenograft tumor model.

RESULTS

Celastrol increased the level of autophagy in pancreatic cancer cells. Furthermore in vitro, when inhibiting the autophagy with 3-MA, the level of celastrol-induced apoptosis elevated; after upgrading autophagy by starvation, the level of celastrol-induced apoptosis descended. 3-MA enhanced celastrol-induced apoptosis and inhibitory effect on tumor growth in vivo.

CONCLUSIONS

In pancreatic cancer, celastrol treatment increased the level of autophagy to protect cancer cells against apoptosis. Autophagy inhibitor 3-MA could improve the therapeutic effect of celastrol in vitro and in vivo.

Bioresorbable zinc hydroxyapatite guided bone regeneration membrane for bone regeneration

OBJECTIVES

The aim of this study was to investigate the bone regenerative properties of a heat treated cross-linked GBR membrane with zinc hydroxyapatite powders in the rat calvarial defect model over a 6-week period.

MATERIAL AND METHODS

In vitro physio-chemical characterization involved X-ray diffraction analysis, surface topology by scanning electron microscopy, and zinc release studies in physiological buffers. Bilateral rat calvarial defects were used to compare the Zn-HAp membranes against the commercially available collagen membranes and the unfilled defect group through radiological and histological evaluation.

RESULTS

The synthesized Zn-MEM (100 μm thick) showed no zinc ions released in the phosphate buffer solution (PBS) buffer, but zinc was observed under acidic conditions. At 6 weeks, both the micro-CT and histological analyses revealed that the Zn-MEM group yielded significantly greater bone formation with 80 ± 2% of bone filled, as compared with 60 ± 5% in the collagen membrane and 40 ± 2% in the unfilled control group.

CONCLUSION

This study demonstrated the use of heat treatment as an alternative method to cross-linking the Zn-MEM to be applied as a GBR membrane. Its synthesis and production are relatively simple to fabricate, and the membrane had rough surface features on one side, which might be beneficial for cellular activities. In a rat calvarial defect model, it was shown that new bone formation was accelerated in comparison with the collagen membrane and the unfilled defect groups. These results would suggest that Zn-MEM has the potential for further development in dental applications.

Physical activity, body mass index and mental health in Chinese adolescents: a population based study

AIM

The aim of the present study was to examine the association between physical activity, BMI level and mental health among Chinese adolescents.

METHODS

Three thousand ninety-six adolescents aged 11 to 13 were analyzed from 6 middle schools of Xuzhou. Physical activity level was measured using self-designed questionnaires. BMI was calculated according to the results of these students' physical examinations. Anxiety symptoms were assessed by using the Screen for Child Anxiety Related Emotional Disorder, depression via the Children's Depression Inventory. Data were analyzed using chi-square test and logistic regression.

RESULTS

Adolescents' self-reported rate of insufficient physical activity was 58.1%. The overweight and obesity rates were 18.4%, 16.0%. The point prevalence rates on anxiety and depression were 15.2%, 11.5%. Insufficient physical activity was positively associated with anxiety and depression (OR [95%CI]: 1.31 [1.06-1.63]; 1.33 [1.04-1.70]). Obesity was positively associated with depression (OR [95%CI]: 1.48 [1.10-2.00]). IS-OB was positively associated with anxiety and depressive (OR [95%CI]: 1.71 [1.19-2.45]; 1.99 [1.33-2.97]).

CONCLUSION

Physical inactivity and overweight/obesity were negatively association with mental health of adolescents, respectively. Meanwhile, to explore the combined effects of physical inactivity and obesity would increase the risk of anxiety and depression in adolescents.

Identification of differently expressed genes and small molecule drugs for Tetralogy of Fallot by bioinformatics strategy

This study aimed to screen out differentially expressed genes (DEGs) and explore small molecule drugs for Tetralogy of Fallot (TOF). The gene expression profile of TOF GSE26125 was downloaded from the Gene Expression Omnibus database, including 16 idiopathic TOF samples and five healthy controls. The DEGs were identified by the Limma package in R language and underwent functional enrichment analysis via Database for Annotation, Visualization and Integrated Discovery tools. A protein-protein interaction (PPI) network of DEGs was then constructed and the significant clusters were selected for functional analysis. In addition, the DEGs were mapped to the connectivity map (CMap) database to identify potential small-molecule drugs. As a result, a total of 499 DEGs were selected between TOF and healthy controls. Meanwhile, the functional changes of DEGs related to TOF were mainly associated with cellular respiration and energy metabolism. Furthermore, in the PPI network, two clusters were identified via cluster 1 analysis. And only cluster 1 was significantly enriched into gene ontology terms, including respiratory chain, electron transport chain, and oxidation reduction. The hub gene of cluster 1 was NDUFAB1. Additionally, small molecules, such as harmine, solanine, and testosterone, may have the potential to repair the disordered metabolic pathways of TOF.

Bipolar radiofrequency ablation is useful for treating atrial fibrillation combined with heart valve diseases

BACKGROUND

Atrial fibrillation (AF) is a common arrhymia, and it results in increased risk of thromboembolism and decreased cardiac function. In patients undergoing cardiac surgery, concomitant radiofrequency ablation to treat AF is effective in restoring sinus rhythm (SR). This study is an observational cohort study aimed to investigate the safety and efficacy of bipolar radiofrequency ablation (BRFA) for treating AF combined with heart valve diseases.

METHODS

Clinical data were analyzed retrospectively from 324 cases of rheumatic heart disease combined with persistent AF patients who underwent valve replacement concomitant BRFA. The modified left atrial and the simplified right atrial ablation were used for AF treatments. Of the 324 patients, 248 patients underwent mitral valve replacement and 76 patients underwent double valve replacement. Meanwhile, 54 patients underwent concomitant thrombectomy and 97 underwent tricuspid valvuloplasty. And all of them received temporary pacemaker implantation. The 24 hours holter electrocardiogram (ECG) monitoring and echocardiography was performed before the operation, on the first day after operation, on discharge day, and at 6 and 12 months after operation.

RESULTS

There were 299 patients with SR on the first day after operation (92.30%), 12 patients with junctional rhythm (3.70%), 11 patients with AF (3.39%), and 2 patients with atrial flutter (0.62%). The temporary pacemaker was used in 213 patients (65.74%) with heart rates less than 70 beat/minute in the ICU. Two patients died early and the mortality rate was 0.62%. Two patients had left ventricular rupture and the occurrence rate was 0.62%. They both recovered. There was no degree III atrioventricular blockage and no permanent pacemaker implantation. Overall survival rate was 99.38% (322 cases) with SR conversion rate of 89.13% (287 cases) at discharge. The SR conversion rate was 87.54% and 87.01% at 6 and 12 months after operation. Sinus bradycardia occurred in 3.42% of patients at 6 months after operation and in 3.03% of patients at 12 months after operation. Echocardiography showed that the left atrial diameter was significantly decreased, and ejection fraction and fractional shortening were significantly improved.

CONCLUSIONS

BRFA for treating AF in concomitant valve replacement is safe and with good efficacy.

Optimization of culture medium for anaerobic production of rhamnolipid by recombinant Pseudomonas stutzeri Rhl for microbial enhanced oil recovery

Response surface methodology was employed to enhance the anaerobic production of rhamnolipid by recombinant Pseudomonas stutzeri Rhl. Glycerol is a promising carbon source used to anaerobically produce rhamnolipid. In a Plackett-Burman design, glycerol, KH2 PO4 and yeast extract were significant factors. The proposed optimized medium contained the following: 46·55 g l(-1) glycerol; 3 g l(-1) NaNO3 ; 5·25 g l(-1) K2 HPO4 ·3H2 O; 5·71 g l(-1) KH2 PO4 ; 0·40 g l(-1) MgSO4 ·7H2 O; 0·13 g l(-1) CaCl2 ; 1·0 g l(-1) KCl; 1·0 g l(-1) NaCl; and 2·69 g l(-1) yeast extract. Using this optimized medium, we obtained an anaerobic yield of rhamnolipid of 3·12 ± 0·11 g l(-1) with a 0·85-fold increase. Core flooding test results also revealed that Ps. stutzeri Rhl grown in an optimized medium enhanced the oil recovery efficiency by 15·7%, which was 6·6% higher than in the initial medium. Results suggested that the optimized medium is a promising nutrient source that could effectively mobilize oil by enhancing the in situ production of rhamnolipid.

SIGNIFICANCE AND IMPACT OF THE STUDY

The ex situ application of rhamnolipid for microbial enhanced oil recovery (MEOR) is costly and complex in terms of rhamnolipid production, purification and transportation. Compared with ex situ applications, the in situ production of rhamnolipid in anaerobic oil reservoir is more advantageous for MEOR. This study is the first to report the anaerobic production optimization of rhamnolipid. Results showed that the optimized medium enhanced not only the anaerobic production of rhamnolipid but also crude oil recovery.

Low adenosine triphosphate activity in CD4+ cells predicts infection in patients with lupus nephritis

OBJECTIVES

The ImmuKnow (Cylex) assay has been reported to predict the risk of infection in some diseases; however, it is uncertain whether ImmuKnow can predict the risk of infection in lupus nephritis (LN) patients receiving immunosuppressive therapy.

METHODS

The ImmuKnow Immune Cell Function Assay (Cylex, Inc., Columbia, MD, USA) was applied to measure the activity of CD4+ T cells, as a marker of global immune-competence. The correlation between changes in T cell activation and the relative risk of over-immunosuppression as well as infection was studied. The amount of adenosine triphosphate (ATP) produced by CD4+ T cells in response to phytohemagglutinin (PHA) was measured for 74 LN patients without infection, 22 LN patients with severe infection (i.e. required hospitalisation), and 28 healthy controls.

RESULTS

No correlation was found between the ATP level and systemic lupus erythematosus (SLE) activity. The mean ATP level was significantly lower in LN patients with infection than that in healthy controls (p<0.01) and non-infected LN patients (p<0.01). The mean ATP level in non-infected LN patients was not significantly different compared to healthy controls. A cut-off ATP value of 300 ng/mL predicted infection in LN patients with a specificity of 77% and a sensitivity of 77%. Multi-variable partial correlation coefficient between the ATP assay and severe infection was r =-0.040, p<0.001; CRP was r=0.962, p<0.001.

CONCLUSIONS

The ImmuKnow assay may be effective in identifying an increased risk of infection in LN patients but is not correlated with SLE activity. Combined CRP value will increase the diagnostic rate of severe infection in SLE. Larger studies are required to establish clinical advantages of this assay in SLE treatment.

Effect of biomimetic zinc-containing tricalcium phosphate (Zn-TCP) on the growth and osteogenic differentiation of mesenchymal stem cells

Several studies have shown the effectiveness of zinc-tricalcium phosphate (Zn-TCP) for bone tissue engineering. In this study, marine calcareous foraminifera possessing uniform pore size distribution were hydrothermally converted to Zn-TCP. The ability of a scaffold to combine effectively with mesenchymal stem cells (MSCs) is a key tissue-engineering aim. In order to demonstrate the osteogenic ability of MSCs with Zn-TCP, the scaffolds were cultured in an osteogenic induction medium to elicit an osteoblastic response. The physicochemical properties of Zn-TCP were characterized by XRD, FT-IR and ICP-MS. MSCs were aspirated from rat femurs and cultured for 3 days before indirectly placing four samples into each respective well. After culture for 7, 10 and 14 days, osteoblastic differentiation was evaluated using alizarin red S stain, measurement of alkaline phosphatase (ALP) levels, cell numbers and cell viability. XRD and FT-IR patterns both showed the replacement of CO(3)(2-) with PO(4)(3-). Chemical analysis showed zinc incorporation of 5 mol%. Significant increases in cell numbers were observed at 10 and 14 days in the Zn-TCP group, while maintaining high levels of cell viability (> 90%). ALP activity in the Zn-TCP group was statistically higher at 10 days. Alizarin red S staining also showed significantly higher levels of calcium mineralization in Zn-TCP compared with the control groups. This study showed that MSCs in the presence of biomimetically derived Zn-TCP can accelerate their differentiation to osteoblasts and could potentially be useful as a scaffold for bone tissue engineering.

Contribution of the organic anion transporter OAT2 to the renal active tubular secretion of creatinine and mechanism for serum creatinine elevations caused by cobicistat

Many xenobiotics including the pharmacoenhancer cobicistat increase serum creatinine by inhibiting its renal active tubular secretion without affecting the glomerular filtration rate. This study aimed to define the transporters involved in creatinine secretion, applying that knowledge to establish the mechanism for xenobiotic-induced effects. The basolateral uptake transporters organic anion transporter OAT2 and organic cation transporters OCT2 and OCT3 were found to transport creatinine. At physiologic creatinine concentrations, the specific activity of OAT2 transport was over twofold higher than OCT2 or OCT3, establishing OAT2 as a likely relevant creatinine transporter and further challenging the traditional view that creatinine is solely transported by a cationic pathway. The apical multidrug and toxin extrusion transporters MATE1 and MATE2-K demonstrated low-affinity and high-capacity transport. All drugs known to affect creatinine inhibited OCT2 and MATE1. Similar to cimetidine and ritonavir, cobicistat had the greatest effect on MATE1 with a 50% inhibition constant of 0.99 μM for creatinine transport. Trimethoprim potently inhibited MATE2-K, whereas dolutegravir preferentially inhibited OCT2. Cimetidine was unique, inhibiting all transporters that interact with creatinine. Thus, the clinical observation of elevated serum creatinine in patients taking cobicistat is likely a result of OCT2 transport, facilitating intracellular accumulation, and MATE1 inhibition.

Bone regeneration of calvarial defect using marine calcareous-derived beta-tricalcium phosphate macrospheres

The aim of this study was to examine the bone regeneration properties of beta-tricalcium phosphate hydrothermally converted from foraminifera carbonate exoskeleton in the repair of rat calvarial defect. These natural materials possess unique interconnected porous network with uniform pore size distribution, which can be potentially advantageous. In total, 20 adult male Wistar rats received full-thickness calvarial defect with a diameter of 5 mm. The rate of newly formed bone was measured radiologically by X-ray and micro-computed tomography and by histologic examination. After 2 weeks, the beta-tricalcium phosphate group exhibited full closure of the defect site, while control group remained unrestored at the end of the 6-week experimentation. It was observed that the newly regenerated bone thickened over the course of the experiment in the beta-tricalcium phosphate group. No soft tissue reaction was observed around the beta-tricalcium phosphate implant and the rats remained healthy. These results showed that repair of the calvarial defect can be achieved by biomimetic beta-tricalcium phosphate macrospheres, which hold potential for application as bone grafts for bone augmentation surgeries.

Claire RL, Brouwer KR, Ray AS. Evaluation of the endothelin receptor antagonists ambrisentan, bosentan, macitentan, and sitaxsentan as hepatobiliary transporter inhibitors and substrates in sandwich-cultured human hepatocytes

Background

Inhibition of the transporter-mediated hepatobiliary elimination of bile salts is a putative mechanism for liver toxicity observed with some endothelin receptor antagonists (ERAs).

Methods

Sandwich-cultured human hepatocytes were used to study the hepatobiliary distribution and accumulation of exogenous taurocholate, ERAs and endogenous bile acids. The molecular mechanisms for findings in hepatocytes or clinical observations were further explored using either vesicular assays (efflux transporters) or transfected cell-lines (uptake transporters). Inhibition constants (IC₅₀) were measured for the human hepatobiliary transporters bile salt export pump (BSEP), sodium taurocholate cotransporting polypeptide (NTCP), multidrug resistance protein 2 (MRP2), P-glycoprotein (Pgp), breast cancer resistance protein (BCRP), organic anion-transporting polypeptide 1B1 (OATP1B1) and OATP1B3.

Results

The ERAs showed dose-dependent reductions in exogenous taurocholate cellular accumulation in human hepatocytes, with macitentan having the greatest effect. Consistent with their effects on bile acids, the ERAs inhibited bile transporters. IC₅₀ values for OATP1B1 and OATP1B3 ranged from 2 µM for macitentan to 47 µM for ambrisentan. Macitentan and bosentan also inhibited NTCP with IC₅₀ values of 10 and 36 µM, respectively. Similar to previously reported findings with sitaxsentan, BSEP inhibition was observed for bosentan and macitentan with IC₅₀ values of 42 and 12 µM, respectively. In contrast, ambrisentan showed little or no inhibition of these transporters. Other transporters tested were weakly inhibited by the ERAs. Accumulation in hepatocytes was also a factor in the effects on bile transport. Macitentan demonstrated the greatest accumulation in human hepatocytes (∼100x) followed by sitaxsentan (∼40x), bosentan (∼20x) and ambrisentan (∼2x).

Conclusions

Significant differences in the inhibition of hepatic transporters were observed between the evaluated ERAs in vitro. Macitentan had the highest level of cellular accumulation and caused the greatest effects on bile acid distribution in human hepatocytes followed by sitaxsentan and bosentan. Ambrisentan showed a low potential to affect bile acids.

Production and characterization of recombinant glucose oxidase from Aspergillus niger expressed in Pichia pastoris

Recombinant glucose oxidase from Aspergillus niger expressed in Pichia pastoris by fed-batch fermentation was purified and assessed with 1·26 purification fold to homogeneity using Q-Sepharose F.F. chromatography. The enzyme was determined by SDS-PAGE and gradient PAGE, which showed a dimeric form of 150 kDa. The purified rGOD was proved to be a glycoprotein, and the content of which was estimated to be 36·7 and 25·14% by phenol-sulfuric acid and anthrone-sulfuric acid methods. Characteristics demonstrated that the highest activity was in pH 6·0 at 40°C and was stable at a broad pH range from 4·0 to 9·0 at 55°C or below. The optimum substrate for this enzyme was d-glucose, and the Km was 21·06 mmol l(-1) as well as the Vmax was 359 μmol min(-1) mg(-1). rGOD possessed high resistance to various chemicals except for Hg(2+), Fe(2+), Ag(+), Cu(2+), 1,4-dithiothreitol, sodium dodecyl sulfate and ascorbic acid. In addition, the inhibitors also exhibited intensive fluorescence quenching effect on rGOD.

SIGNIFICANCE AND IMPACT OF THE STUDY

Glucose oxidase is a very important enzyme produced by several species. However, large-scale applications have always been postponed by its complexity in fermentation and purification. Our research focused on developing new purification strategy of recombinant GOD from A. niger expressed in P. pastoris. Here, we described this novel one-step purification method and subsequent research in the characteristics of rGOD which showed different results from previous work. These can open new opportunities to increase its application.

Bone regeneration of rat tibial defect by zinc-tricalcium phosphate (Zn-TCP) synthesized from porous Foraminifera carbonate macrospheres

Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP) as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair.

Residual ridge dimensions at edentulous maxillary first molar sites and periodontal bone loss among two ethnic cohorts seeking tooth replacement

OBJECTIVES

To study residual ridge dimensions at edentulous first molar sites in relation to periodontal bone loss among cohorts of partially edentulous Asian Indian and Hong Kong Chinese subjects seeking tooth replacement.

MATERIALS AND METHODS

A total of 628 edentulous maxillary first molar sites were analyzed on Cone Beam Computed Tomography scans of 225 Asian Indian (I) and 232 Hong Kong Chinese (C) partially edentulous adults seeking tooth replacement. Age, ethnicity, gender, total tooth loss, the presence or absence of adjacent teeth, categories of periodontal status defined according to radiographic alveolar bone loss (P0: periodontal health, P1: incipient to moderate disease, P2: severe periodontal disease) and sinus membrane abnormalities were noted. Alveolar ridge height (RH), widths at 1 and 3 mm from crest (RW1; RW3), and relative position of the bone crest (RR) were measured.

RESULTS

Prevalence of P2 status was most frequent in both cohorts(C: 50.4% I: 49.2%). P2 had lowest ridge heights; 13.1% C P2 and 14%I P2 had RH < 2 mm. Sites with both RH <8 mm and RW1 < 6 mm occurred at 59%C P2 and 68%I P2. Sinus membrane abnormalities were most frequent in P2. Periodontal status and sinus membrane abnormality increased the odds of RH <5 mm and RH <8 mm more than 2-fold; additionally, gender and ethnicity significantly impacted RH <8 mm. Gender and adjacent tooth status significantly affected RW1.

CONCLUSION

Incident advanced periodontal disease was common among Asian Indian and Hong Kong Chinese subjects seeking tooth replacement and associated with lower available bone heights. Ethnicity, gender, sinus membrane thickening affected available bone height in the subsinus region, while the presence of adjacent teeth- and age-affected residual ridge width.