Inhibition of microRNA-21 decreases the invasiveness of fibroblast-like synoviocytes in rheumatoid arthritis via TGFβ/Smads signaling pathway

OBJECTIVES

MicroRNA-21 (miR21) is aberrantly elevated in rheumatoid arthritis (RA) patients, the significance of this microRNA in RA pathogenesis and treatment, however, has not been investigated. In this study, by using RA-derived fibroblast-like synoviocyte (FLS) cells as a model, we investigated the effect and corresponding mechanism of miR21 inhibition on FLSs invasion.

MATERIALS AND METHODS

miR21 expression in synovial tissue and FLSs in RA patients and non-RA controls were determined by stem-loop RT-PCR. The effect of miR21 on FLSs viability and invasiveness were evaluated using miR21 inhibition. Cell viability was evaluated by MTT assay and the expression of genes at mRNA and protein levels was determined by RT-PCR and Western blot, respectively.

RESULTS

Our results showed that miR21 expression was highly increased in synovial tissue and FLSs in RA patients. Also, we reported that miR21 inhibitor treatment could significantly suppress the invasiveness of FLSs without affecting cell viability. The decreased FLSs invasion by miR21 inhibition was associated with down-regulated expression of matrix metalloproteinase (MMP)-1, MMP3, and MMP13. Further analysis revealed that miR21 inhibition could suppress the expression of TGFβ1 and Smad4, but promote that of Smad7. Moreover, suppression of FLS invasion and MMPs expression by miR21 treatment could be counteracted by additional TGFβ1 treatment.

CONCLUSION

Our results indicated that miR21 inhibition can down-regulate the expression of MMP1, MMP3, and MMP13 and consequently suppress the invasiveness of FLS, which is achieved through TGFβ1/Smad4/7 signaling pathway. The findings of this study could offer a novel approach for RA treatment.

The Effectiveness of hCG and LHRH in Boys with Cryptorchidism: A Meta-Analysis of Randomized Controlled Trials

To systematically review the efficacy of hCG and LHRH on testicular descent in boys with cryptorchidism, comprehensive search was performed to identify randomized controlled trials (RCTs) in PubMed, EMBASE, the Cochrane Library, Wanfang Database, and China National Knowledge Infrastructure (CNKI) up to March 2014. Outcomes included testicular complete descent rate (TCDR) and cure rate of patients. Study quality was evaluated using the Jadad scale. Meta-analysis was performed using Review Manager software. Finally, 13 studies were included. hCG and LHRH increased TCDR comparing with control group. The success rate of hCG and LHRH was 24 and 19%, respectively. Further, hCG and LHRH had significant effect on bilateral cryptorchidism, but not on unilateral cryptorchidism. All side effects were transitory and not severe, but if they have long-term harms were not clear. hCG and LHRH can effectively increase TCDR and there was no significant difference between them. However, the hormones cannot be recommended for everyone because of their low success rates and potential long-term harms. Further studies are needed to determine the efficacy of hormonal treatment for subtypes of cryptorchidism.

Pdcd4 restrains the self-renewal and white-to-beige transdifferentiation of adipose-derived stem cells

The stemness maintenance of adipose-derived stem cells (ADSCs) is important for adipose homeostasis and energy balance. Programmed cell death 4 (Pdcd4) has been demonstrated to be involved in the development of obesity, but its possible roles in ADSC function and adipogenic capacity remain unclear. In this study, we demonstrate that Pdcd4 is a key controller that limits the self-renewal and white-to-beige transdifferentiation of ADSCs. Pdcd4 deficiency in mice caused stemness enhancement of ADSCs as evidenced by increased expression of CD105, CD90, Nanog and Oct4 on ADSCs, together with enhanced in situ proliferation in adipose tissues. Pdcd4 deficiency promoted proliferation, colony formation of ADSCs and drove more ADSCs entering the S phase accompanied by AKT activation and cyclinD1 upregulation. Blockade of AKT signaling in Pdcd4-deficient ADSCs led to a marked decline in cyclinD1, S-phase entry and cell proliferation, revealing AKT as a target for repressing ADSC self-renewal by Pdcd4. Intriguingly, depletion of Pdcd4 promoted the transdifferentiation of ADSCs into beige adipocytes. A reduction in lipid contents and expression levels of white adipocyte markers including C/EBPα, PPAR-γ, adiponectin and αP2 was detected in Pdcd4-deficient ADSCs during white adipogenic differentiation, substituted by typical beige adipocyte characteristics including small, multilocular lipid droplets and UCP1 expression. More lactate produced by Pdcd4-deficient ADSCs might be an important contributor to the expression of UCP1 and white-to-beige transdifferentiation. In addition, an elevation of UCP1 expression was confirmed in white adipose tissues from Pdcd4-deficient mice upon high-fat diet, which displayed increased energy expenditure and resistance to obesity as compared with wild-type obese mice. These findings provide evidences that Pdcd4 produces unfavorable influences on ADSC stemness, which contribute to adipose dysfunction, obesity and metabolic syndromes, thereby proposing Pdcd4 as a potential intervening target for regulating ADSC function.

Surface Collective Modes in the Topological Insulators Bi_{2}Se_{3} and Bi_{0.5}Sb_{1.5}Te_{3-x}Se_{x}

We used low-energy, momentum-resolved inelastic electron scattering to study surface collective modes of the three-dimensional topological insulators Bi_{2}Se_{3} and Bi_{0.5}Sb_{1.5}Te_{3-x}Se_{x}. Our goal was to identify the "spin plasmon" predicted by Raghu and co-workers [Phys. Rev. Lett. 104, 116401 (2010)]. Instead, we found that the primary collective mode is a surface plasmon arising from the bulk, free carriers in these materials. This excitation dominates the spectral weight in the bosonic function of the surface χ^{"}(q,ω) at THz energy scales, and is the most likely origin of a quasiparticle dispersion kink observed in previous photoemission experiments. Our study suggests that the spin plasmon may mix with this other surface mode, calling for a more nuanced understanding of optical experiments in which the spin plasmon is reported to play a role.

Polarization-resolved spectroscopy imaging of grain boundaries and optical excitations in crystalline organic thin films

Exploration of optical properties of organic crystalline semiconductors thin films is challenging due to submicron grain sizes and the presence of numerous structural defects, disorder and grain boundaries. Here we report on the results of combined linear dichroism (LD)/ polarization-resolved photoluminescence (PL) scanning microscopy experiments that simultaneously probe the excitonic radiative recombination and the molecular ordering in solution-processed metal-free phthalocyanine crystalline thin films with macroscopic grain sizes. LD/PL images reveal the relative orientation of the singlet exciton transition dipoles at the grain boundaries and the presence of a localized electronic state that acts like a barrier for exciton diffusion across the grain boundary. We also show how this energy barrier can be entirely eliminated through the optimization of deposition parameters that results in films with large grain sizes and small-angle boundaries. These studies open an avenue for exploring the influence of long-range order on exciton diffusion and carrier transport.

In-depth understanding of organic crystalline semiconductor thin films is critical for the development of many electronic and photonic devices. Here, the authors use combined linear dichroism and polarization-resolved photoluminescence scanning microscopy to unveil the nature of excited states in such systems.

Peroxisome proliferator-activated receptorβ/δ activation is essential for modulating p-Foxo1/Foxo1 status in functional insulin-positive cell differentiation

Peroxisome proliferator-activated receptors (PPARs) participate in energy homeostasis and play essential roles in diabetes therapy through their effects on non-pancreas tissues. Pathological microenvironment may influence the metabolic requirements for the maintenance of stem cell differentiation. Accordingly, understanding the mechanisms of PPARs on pancreatic β-cell differentiation may be helpful to find the underlying targets of disrupted energy homeostasis under the pancreatic disease condition. PPARs are involved in stem cell differentiation via mitochondrial oxidative phosphorylation, but the subtype member activation and the downstream regulation in functional insulin-positive (INS⁺) cell differentiation remain unclear. Here, we show a novel role of PPARβ/δ activation in determining INS⁺ cell differentiation and functional maturation. We found PPARβ/δ expression selectively upregulated in mouse embryonic pancreases or stem cells-derived INS⁺ cells at the pancreatic mature stage in vivo and in vitro. Strikingly, given the inefficiency of generating INS⁺ cells in vitro, PPARβ/δ activation displayed increasing mouse and human ES cell-derived INS⁺ cell numbers and insulin secretion. This phenomenon was closely associated with the forkhead box protein O1 (Foxo1) nuclear shuttling, which was dependent on PPARβ/δ downstream PI3K/Akt signaling transduction. The present study reveals the essential role of PPARβ/δ activation on p-Foxo1/Foxo1 status, and in turn, determining INS⁺ cell generation and insulin secretion via affecting pancreatic and duodenal homeobox-1 expression. The results demonstrate the underlying mechanism by which PPARβ/δ activation promotes functional INS⁺ cell differentiation. It also provides potential targets for anti-diabetes drug discovery and hopeful clinical applications in human cell therapy.

Placental miR-106a∼363 cluster is dysregulated in preeclamptic placenta

Preeclampsia (PE) is the leading cause of maternal and perinatal mortality and morbidity. MicroRNAs are strongly implicated in the pathogenesis of this syndrome. In current study, we performed a microarray assay to explore miRNA expression profile in the placenta, and found 11 upregulated and 7 downregulated miRNAs in preeclampsia. miR-363, plus other 5 member of miR-106a∼363 cluster was further examined and validated. These findings would facilitate further investigation of aberrant expression of miRNAs in the pathology of preeclampsia.

Polymorphisms in the TNF-α, TNFR1 gene and risk of rheumatoid arthritis in Chinese Han population

Recent advances have highlighted a major genetic contribution to the pathogenesis of rheumatoid arthritis (RA).The aim of this study was to investigate whether polymorphisms of TNF-α (rs1800630, rs1800629) and TNFR1 (rs767455) were associated with susceptibility to and clinical outcome of RA in Chinese Han population. The target gene polymorphisms were genotyped in 256 patients with RA and 331 healthy controls using a high resolution melting (HRM) method. ESR, CRP, RF anti-CCP and anti-GPI level were also assayed and compared in genotypes of each polymorphism. Significant difference was observed in the genotype distributions and allele frequencies of TNF-α rs1800629 (P = 0.001, P < 0.001, respectively) between patients with RA and controls. There is no evidence to suggest an association between genotypes of the 3 SNPs according to age, gender, disease duration, DAS28 and serum level of autoantibodies. This study identifies a potentially important role for TNF-α rs1800629 polymorphisms in the susceptibility to RA.However, further studies in larger cohorts are required.

Circulating chemerin levels are increased in first-degree relatives of type 2 diabetic patients

BACKGROUND

Chemerin is an important risk factor of insulin resistance and metabolic syndrome. The aim of this study was to explore the potential role of chemerin in the early stage of diabetes development.

METHODS

63 control subjects without any family history of diabetes and with normal glucose tolerance (NGT) and 74 healthy, first-degree relatives (FDRs) of type 2 diabetic patients were recruited in the study. All subjects underwent a 75 g oral glucose tolerance (OGTT) test after having fasted overnight. Plasma glucose, insulin, total cholesterol, HDL cholesterol, triglycerides, chemerin, and adiponectin were measured.

RESULTS

FDR subjects had higher BMI, WHR, waist, fasting plasma glucose, fasting insulin, TG, UA, HOMA-IR, LDL-C, and lower HDL- C levels than control subjects (p < 0.05). The FDRs group had significantly lower adiponectin levels while chemerin was higher. Plasma chemerin levels were independently correlated with HOMA-IR, FINS, TG, FPG, and adiponectin level. Multiple stepwise regression analysis showed that HOMA-IR and TG were independent risk factors that influenced circulating chemerin levels.

CONCLUSIONS

These findings showed a significant increase of chemerin levels in FDR subjects which suggested that chemerin may be involved in the development and progression of insulin resistance.

The Crystallinity of PVC and its Effect on Physical Properties**

Differential scanning calorimetry (DSC) was used to investigate the crystallinity of crude PVC powders and annealed PVC compounds. Crude PVC powder exhibited a broad crystallite fusion endotherm ranged from 110°C to 220°C. High degree of polymerization of PVC showed high degree of crystallinity both for powder and annealed sample under the same annealing conditions. Annealing conditions (time and temperature) had large effects on recrystallization behavior of PVC. The crystallinity of PVC decreased with increasing of DOP plasticizer content in PVC compounds, and lead to decrease of modulus and increase of average molecular weight between physical crosslinks.

Identification of the antibiotic ionomycin as an unexpected peroxisome proliferator-activated receptor γ (PPARγ) ligand with a unique binding mode and effective glucose-lowering activity in a mouse model of diabetes

AIMS/HYPOTHESIS

Existing thiazolidinedione (TZD) drugs for diabetes have severe side effects. The aim of this study is to develop alternative peroxisome proliferator-activated receptor γ (PPARγ) ligands that retain the benefits in improving insulin resistance but with reduced side effects.

METHODS

We used AlphaScreen assay to screen for new PPARγ ligands from compound libraries. In vitro biochemical binding affinity assay and in vivo cell-based reporter assay were used to validate ionomycin as a partial ligand of PPARγ. A mouse model of diabetes was used to assess the effects of ionomycin in improving insulin sensitivity. Crystal structure of PPARγ complexed with ionomycin revealed the unique binding mode of ionomycin, which elucidated the molecular mechanisms allowing the discrimination of ionomycin from TZDs.

RESULTS

We found that the antibiotic ionomycin is a novel modulating ligand for PPARγ. Both the transactivation and binding activity of PPARγ by ionomycin can be blocked by PPARγ specific antagonist GW9662. Ionomycin interacts with the PPARγ ligand-binding domain in a unique binding mode with properties and epitopes distinct from those of TZD drugs. Ionomycin treatment effectively improved hyperglycaemia and insulin resistance, but had reduced side effects compared with TZDs in the mouse model of diabetes. In addition, ionomycin effectively blocked the phosphorylation of PPARγ at Ser273 by cyclin-dependent kinase 5 both in vitro and in vivo.

CONCLUSIONS/INTERPRETATION

Our studies suggest that ionomycin may represent a unique template for designing novel PPARγ ligands with advantages over current TZD drugs.

NORM situation in non-uranium mining in China

The Ministry of Environmental Protection in China is responsible for regulatory control on radiation protection from naturally occurring radioactive material (NORM). The natural radiation caused by human activities is a major contributor to public and occupational exposure in China. This paper introduces the first national census on pollution sources (target year 2007) in China, and describes NORM sites in Baotou, Inner Mongolia, one of the largest rare earth deposits in China. The ores are rich in radioactive elements, with a concentration of ThO(2) of 0.01-0.05% and concentration of U(3)O(8) of 0.0005-0.002%. The large amount of NORM residues is regulated and controlled. After treatment of the waste water, it is discharged into tailing ponds and then pumped directly to milling plants for re-use. The waste gas after off-dust cleaning is discharged into the environment. A substantial amount of blast furnace iron slag from the waste treatment is transformed into cement, concrete, and bricks, or used directly for highway construction. This raises a serious environmental concern. As a result, environmental radiation monitoring and assessment have been introduced recently. Regulatory control of NORM is very important in order to take effective measures to lower the dose.

Selective hepatic vascular exclusion versus Pringle manoeuvre in liver resection for tumours encroaching on major hepatic veins

Background

Control of bleeding is crucial during liver resection, and several techniques have been developed to achieve this. This study compared the safety and efficacy of selective hepatic vascular exclusion (SHVE) and Pringle manoeuvre in partial hepatectomy for liver tumours compressing or involving major hepatic veins.

Methods

All patients undergoing liver resection between January 2003 and December 2010 for liver tumours compressing or involving one or more major hepatic veins were identified retrospectively from a prospective institutional database. Either SHVE or Pringle manoeuvre was used to minimize blood loss during hepatectomy. Data on demographics and the intraoperative and postoperative course were analysed.

Results

From the database of 3900 patients, 1420 were identified who underwent liver resection for tumours encroaching on major hepatic veins using either SHVE (550) or the Pringle manoeuvre (870). Intraoperative blood loss (mean(s.d.) 480(210) versus 830(340) ml; P = 0·007) and transfusion requirements (mean(s.d.) 1·3(0·6) versus 2·9(1·4) units; P = 0·008) were significantly less in the SHVE group. In the Pringle group, hepatic vein injury resulted in major intraoperative bleeding of over 1000 ml in 65 patients (7·5 per cent) and air embolism in 14 (1·6 per cent), and three patients (0·3 per cent) died during surgery, whereas there was no major bleeding, air embolism or intraoperative death in the SHVE group. Postoperative liver failure, multiple organ failure and in-hospital death were significantly more common in the Pringle group (P = 0·019, P = 0·032 and P = 0·004 respectively).

Conclusion

SHVE was more efficacious than the Pringle manoeuvre in minimizing intraoperative bleeding and air embolism during partial hepatectomy for tumours encroaching on major hepatic veins, and decreased the postoperative liver failure rate.

Effect of Streptococcus sanguinis/Porphyromonas gingivalis single and combined biofilms upon platelet aggregation

OBJECTIVE

To assess the effect of two oral bacteria Streptococcus sanguinis and Porphyromonas gingivalis upon platelet aggregation.

MATERIALS AND METHODS

Streptococcus sanguinis, P. gingivalis, S. sanguniis+P. gingivalis were added to platelet-rich plasma and platelet aggregation measured using a platelet aggregometer. Platelets were passed through a flow chamber with S. sanguinis, P. gingivalis or a biofilm of S. sanguinis and P. gingivalis coated with saliva. Platelet adhesion to the chamber was observed under a fluorescence microscope for 15min. The positive control was platelets treated with adrenaline; the negative control was platelets treated with phosphate-buffered saline.

RESULTS

The mean (± s.e.) aggregation magnitude of S. sanguinis and P. gingivalis was 77.7±7.4% and 79.3±9.9%, respectively. The aggregation magnitude of S. sanguinis+P. gingivalis was 51.3±12.9%, which was significantly lower than that for S. sanguinis/P. gingivalis (P<0.05). In the flow chamber system, platelets adhered to S. sanguinis/P.gingivalis respectively within 3min, and reached a plateau at 5-15min. Under the condition of the S. sanguinis- and P. gingivalis-saliva biofilm, platelet adhesion to the biofilm was significantly reduced at 5-15min (P<0.05).

CONCLUSIONS

In the static or dynamic flow system, platelets adhered to S. sanguinis or P. gingivalis. However, if S. sanguinis was mixed with P. gingivalis, the aggregation magnitude (%) was significantly reduced.

Differential mRNA expression and promoter methylation status of SYCP3 gene in testes of yaks and cattle-yaks

Synaptonemal complex protein 3 (SYCP3) is a DNA-binding protein located on the lateral elements of the synaptonemal complex. This protein plays an important role in homologous chromosome pairing and is necessary for male meiosis of spermatogenesis. To further understand the SYCP3 gene function and its relationship to cattle-yak male sterility, we investigated the characteristics of the bovine SYCP3 (bSYCP3) gene as well as its transcription level and epigenetic modification status. The bSYCP3 gene encodes a 225-amino acid protein with the Cor1 motif and two coiled-coil-forming regions, homologous with other mammals (59-77% identity overall). Real-time PCR analysis indicated that the expression level of bSYCP3 mRNA in yak testes was significantly higher than that in cattle-yak (p < 0.05). The methylation level of the bSYCP3 promoter (mainly 7th, 13th and 17th CpG sites) in cattle-yaks (40%) was significantly higher than that in yaks (0%) (p < 0.05). This suggests that bSYCP3 plays an important role in meiosis of bovine spermatogenesis; further, interspecific hybridization between yak and cattle might influence bSYCP3 gene expression in cattle-yak testes, which might be influenced by bSYCP3 gene promoter methylation.