miR-30e reciprocally regulates the differentiation of adipocytes and osteoblasts by directly targeting low-density lipoprotein receptor-related protein 6

Reciprocal relationship usually exists between osteoblastogenesis and adipogenesis, with factors stimulating one of these processes at the same time inhibiting the other. In the present study, miR-30e was found to be involved in the reciprocal regulation of osteoblast and adipocyte differentiation. Our data indicated that miR-30e was induced in primarily cultured mouse bone marrow stromal cell, mesenchymal cell line C3H10T1/2 and preadipocyte 3T3-L1 after adipogenic treatment. Conversely, it was reduced in mouse stromal line ST2 and preosteoblast MC3T3-E1 after osteogenic treatment. Enforced expression of miR-30e in 3T3-L1 significantly suppressed the growth of the cells and induced the preadipocytes to differentiate into mature adipocytes, along with increased expression of adipocyte-specific transcription factors peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding protein-α (C/EBPα) and C/EBPβ, and the marker gene aP2. In contrast, inhibition of the endogenous miR-30e enhanced the cell growth and repressed preadipocytes to differentiate. Conversely, supplementing miR-30e activity blocked, whereas knocking down miR-30e enforced the preosteoblast MC3T3-E1 to fully differentiate. Furthermore, miR-30e overexpression stimulated adipocyte formation and inhibited osteoblast differentiation from marrow stromal cells. Low-density lipoprotein receptor-related protein 6 (LRP6), one of the critical coreceptor for Wnts, was shown to be a direct target of miR-30e by using the luciferase assay. Knockdown of LRP6 in 3T3-L1 cells downregulated β-catenin/T-cell factor (TCF) transcriptional activity and dramatically potentiated the differentiation of the cells into mature adipocytes. Taken together, the present work suggests that the expression of miR-30e is indispensable for maintaining the balance of adipocytes and osteoblasts by targeting the canonical Wnt/β-catenin signaling.

Structural insights into neutrophilic migration revealed by the crystal structure of the chemokine receptor CXCR2 in complex with the first PDZ domain of NHERF1

Neutrophil plays an essential role in host defense against infection, but uncontrolled neutrophilic infiltration can cause inflammation and severe epithelial damage. We recently showed that CXCR2 formed a signaling complex with NHERF1 and PLC-2, and that the formation of this complex was required for intracellular calcium mobilization and neutrophilic transepithelial migration. To uncover the structural basis of the complex formation, we report here the crystal structure of the NHERF1 PDZ1 domain in complex with the C-terminal sequence of CXCR2 at 1.16 Å resolution. The structure reveals that the CXCR2 peptide binds to PDZ1 in an extended conformation with the last four residues making specific side chain interactions. Remarkably, comparison of the structure to previously studied PDZ1 domains has allowed the identification of PDZ1 ligand-specific interactions and the mechanisms that govern PDZ1 target selection diversities. In addition, we show that CXCR2 can bind both NHERF1 PDZ1 and PDZ2 in pulldown experiments, consistent with the observation that the peptide binding pockets of these two PDZ domains are highly structurally conserved. The results of this study therefore provide structural basis for the CXCR2-mediated neutrophilic migration and could have important clinical applications in the prevention and treatment of numerous neutrophil-dependent inflammatory disorders.

MMP20 modulates cadherin expression in ameloblasts as enamel develops

Matrix metalloproteinase-20 (enamelysin, MMP20) is essential for dental enamel development. Seven different MMP20 mutations in humans cause non-syndromic enamel malformations, termed amelogenesis imperfecta, and ablation of Mmp20 in mice results in thin brittle enamel with a dysplastic rod pattern. Healthy enamel formation requires the sliding movement of ameloblasts in rows during the secretory stage of development. This is essential for formation of the characteristic decussating enamel rod pattern observed in rodents, and this is also when MMP20 is secreted into the enamel matrix. Therefore, we propose that MMP20 facilitates ameloblast movement by cleaving ameloblast cell-cell contacts. Here we show that MMP20 cleaves the extracellular domains of the E- and N-cadherin adherens junction proteins, that both E- and N-cadherin transcripts are expressed at significantly higher levels in Mmp20 null vs. wild-type (WT) mice, and that in Mmp20 ablated mice, high-level ameloblast N-cadherin expression persists during the maturation stage of development. Furthermore, we show that E-cadherin gene expression is down-regulated from the pre-secretory to the secretory stage, while N-cadherin levels are up-regulated. This E- to N-cadherin switch supports epithelial migration in other tissues and may be an important event necessary for the ameloblasts to start moving in rows that slide by one another.

A 12-week intramuscular toxicity study of risperidone-loaded microspheres in Beagle dogs

Long-acting formulations of antipsychotics are important treatment options to increase the compliance of schizophrenic patients. Risperidone, a 5-HT2 and dopaminergic D2 receptor antagonist, was developed as long-acting sustained-release microspheres with poly(lactide-co-glycolide) (PLGA) as a drug carrier for the treatment of schizophrenia. In the present study, the main objective is to determine the nonclinical safety profile of risperidone-loaded microspheres (RM) in Beagle dogs after intramuscular administration for 3 months, once in 2 weeks, followed by 8-week recovery phase. No animal death was found and no special toxicological findings were observed. The findings, such as hypoactivity, ptosis, increased heart rate, and elevated serum and pituitary prolactin levels, were observed and related to the pharmacological effects of risperidone. The changes in the reproductive system (uterus, ovary, vagina, cervix, and mammary gland) were considered secondary to the prolactin elevation, and the congestion of spleen was related to risperidone. The foreign body granulomas at injection sites might be caused by PLGA. At the end of recovery phase, the above changes mostly recovered to normal, and on administering 3 mg/kg dose level once in 2 weeks on Beagle dogs showed no observed adverse effect. Taken together, RM had exhibited the acceptable safety.

Effect of chemical additives on Bacillus thuringiensis (Bacillales: Bacillaceae) against Plutella xylostella (Lepidoptera: Pyralidae)

To examine the effect of chemical additives on Bacillus thuringiensis (Berliner) against Plutella xylostella (L.), inorganic salts, nitrogenous compounds, protein solubilizing agents, and organic acids were selected and tested. The chosen materials are low in cost and environmentally safe. Results show that many inorganic salts can increase the activity of B. thuringiensis in a range of 1.31- to 3.08-fold. These include calcium acetate, calcium chloride, calcium hydroxide, calcium sulfate, calcium carbonate, sodium carbonate, sodium acetate, potassium hydroxide, potassium carbonate, potassium acetate, magnesium chloride, magnesium sulfate, and zinc sulfate. Nitrogenous compounds, including peptone, sodium nitrate, and ammonium nitrate, can enhance the activity of B. thuringiensis 1.62-, 1.32-, and 1.37-fold, respectively. Among the protein solubilizing agents, EDTA, urea, mercaptoethanol and dipotassium hydrogen phosphate increased the activity of B. thuringiensis 1.62- to 2.34-fold. Among the organic acids, maleic and citric acids boosted the activity 1.45- and 1.55-fold, respectively. Meanwhile, sodium benzoate and resorcinol led to 1.74- and 1.44-fold activity gains, respectively. Use of appropriate additives could provide great benefit not only in reducing the costs for field applications of biological insecticides but also by boosting the efficacy of B. thuringiensis.

Studies on High Speed Spinning of PET

It is observed that preoriented yarn (POY) begins orientating crystallization near the area of sharp structural change through the measurements of stress, optical birefringence and density at the speed of 3600 m/min. The investigated relationship between optical birefringence (Δn) and stress (σ) of spinning line proposed by Hamana is, to some extent, deviated from our observation. This paper gives an empirical formulation as Δn = 13.18 × 10−3 + 6.32 × 10−10 σ with a deviation within 4%. It also provides a predicting method for controlling the change of PET structure of spinning line. Our tests have shown that the less the denier of POY single yarn, the greater the stress and crystallinity during the fiber formation, and that stress induced effect of the crystallization kinetics of PET high speed spinning is greater than that of the cooling rate.

A study of circulating anti-CD25 antibodies in non-small cell lung cancer

PURPOSE

Tumors can trigger specific immune response to tumor-associated antigens but the precise mechanism remains unclear. Since regulatory T-lymphocytes (Treg) play a crucial role in controlling autoimmune responses, the present work was undertaken to test whether dysfunction of Treg cells could be involved in developing autoimmunity in patients with lung cancer.

METHODS

In this study, we developed an in-house enzyme-linked immunosorbent assay to test circulating anti-CD25 autoantibodies among 272 patients with non-small cell lung cancer (NSCLC) and 226 control subjects matched in age, gender and smoking history.

RESULTS

Mann-Whitney U test showed that the anti-CD25 IgG level was significantly higher in patients with NSCLC than control subjects (Z = -7.48, P < 0.001) while the anti-CD25 IgA level was not significantly changed in the patient group as compared with the control group (Z = -1.34, P = 0.181). Spearman correlation analysis failed to reveal a significant correlation between the levels of anti-CD25 IgG and IgA either in patients with NSCLC (r = -0.034, P = 0.578) or in control subjects (r = 0.055, P = 0.429). ROC analysis showed an AUC of 0.70 for anti-CD25 IgG, in which NSCLC at stage III had the highest AUC (0.75). The sensitivity against a specificity of >90 % was 35.0 % for anti-CD25 IgG assay with an inter-assay deviation of 9.4 %, and 4.0 % for anti-CD25 IgA assay with an inter-assay deviation of 13.0 %.

CONCLUSIONS

Circulating anti-CD25 IgG antibody may be a useful biomarker for prognosis of lung cancer.

Human leukocyte antigen class I on peripheral blood mononuclear cells as a non-invasive biomarker for esophageal cancer

Esophageal cancer (EC) is a common malignant cancer threatening people's health. There are no universally accepted parameters for its early diagnosis. The aim of this study was to observe the expression of human leukocyte antigen class I (HLA-I) on peripheral blood mononuclear cells (PBMCs) of EC patients and in individuals of high-incidence area of EC so as to evaluate the feasibility of using this parameter as a potential non-invasive biomarker for the early diagnosis of EC. The present study enrolled 58 pathological confirmed EC patients, 46 patients with benign esophageal disease, and 65 healthy volunteers. Expression levels of HLA-I protein and mRNA on PBMCs were determined by flow cytometry and quantitative reverse transcriptase polymerase chain reaction, respectively. Then, 181 volunteers from Lijiadian, a village with high morbidity of EC, and 153 age- and gender-matched health volunteers were involved in this study to observe HLA-I expressions in individuals of high-incidence area of EC. Compared with benign esophageal disease and health volunteers, the expressions of HLA-I protein and mRNA on PBMCs of EC patients are significantly decreased, especially in patients with stage III and IV EC, but was not influenced by patient's age and gender. Furthermore, individuals of high-incidence area of EC also show downregulated HLA-I protein, but not mRNA, expression on PBMCs. Altogether, HLA-I expression on PBMCs of EC patients and individuals from high-incidence area of EC is downregulated, and this parameter might be used as a potential predictor of EC.

Deacetylation of FOXO3 by SIRT1 or SIRT2 leads to Skp2-mediated FOXO3 ubiquitination and degradation

Sirtuin deacetylases and FOXO (Forkhead box, class O) transcription factors have important roles in many biological pathways, including cancer development. SIRT1 and SIRT2 deacetylate FOXO factors to regulate FOXO function. Because acetylation and ubiquitination both modify the ɛ-amino group of lysine residues, we investigated whether FOXO3 deacetylation by SIRT1 or SIRT2 facilitates FOXO3 ubiquitination and subsequent proteasomal degradation. We found that SIRT1 and SIRT2 promote FOXO3 poly-ubiquitination and degradation. Proteasome-inhibitor treatment prevented sirtuin-induced FOXO3 degradation, indicating that this process is proteasome dependent. In addition, we demonstrated that E3 ubiquitin ligase subunit Skp2 binds preferentially to deacetylated FOXO3. Overexpression of Skp2 caused poly-ubiquitination of FOXO3 and degradation, whereas knockdown of Skp2 increased the amount of FOXO3 protein. We also present evidence that SCF-Skp2 ubiquitinates FOXO3 directly in vitro. Furthermore, mutating four known acetylated lysine residues (K242, K259, K290 and K569) of FOXO3 into arginines to mimic deacetylated FOXO3 resulted in enhanced Skp2 binding but with inhibition of FOXO3 ubiquitination; this suggests that some or all of these four lysine residues are likely the sites for ubiquitination. In the livers of mice deficient in SIRT1, we detected increased expression of FOXO3, indicating SIRT1 regulates FOXO3 protein levels in vivo. Furthermore, we found that the elevation of SIRT1 and Skp2 expression in malignant PC3 and DU145 prostate cells is responsible for the downregulation of FOXO3 protein levels in these cells. Taken together, our data support the notion that deacetylation of FOXO3 by SIRT1 or SIRT2 facilitates Skp2-mediated FOXO3 poly-ubiquitination and proteasomal degradation.

CD34 positive cells seeded on small caliber man-made vascular grafts exhibit increased antithrombogenic property compared with unfractioned mononuclear cells

AIM

The aim of this study was to compare the therapeutic potential of purified CD34+ cells with that of unfractioned mononuclear cells (MNCs) for the antithrombogenic property after seeding on the small caliber man-made grafts.

METHODS

Unfractioned MNCs and CD34+ cells were isolated from canine bone marrow. Differentiation of CD34 cells and unfractioned MNCs into endothelial cells were examined by CD31and vWF immunohistochemistry or immunofluorescence stain, endothelial cell function were evaluated via low-density lipoprotein (ac-LDL) - DiL incorpration and in vitro angiogenesis assay. Platelet adhesion assay was performed to determine antiplatelet adhesion property of the cells in vitro. Equal number of both cells were seeded onto the luminal surface of small caliber man-made grafts and implanted to replace a segment of common carotid artery. At different time points (24 h, 72 h, and 1 week) the grafts were retrieved. HE staining and SEM exam were performed.

RESULTS

CD34+ cells acquired significantly more CD31 and VWF expression, increased angiogenic potential and low-density lipoprotein (ac-LDL) incorporation compared to unfractioned MNCs under the induction of VEGF. More platelets were found to adhere to the surface of unfractioned MNCs group than to the CD34+ cell group. In vivo study demonstrated that more platelet adhesion and thrombus formation were observed in the unfractioned MNCs group rather than the CD34+ group. All the grafts in both groups were patent after implantation, except one graft seeded with unfractioned MNCs, occluded at 1 week. Statistically lower ratio of thrombi was found in the CD34+ cell seeding group at 24 h and 1 week after implantation, compared with the unfractioned MNCs one (P<0.05).

CONCLUSION

CD34+ cell exerted better antithrombogenic property than unfractioned MNCs after seeding onto the small caliber vessel grafts.