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ObjectiveExploring the role of microRNA126 （miRNA126） in chronic kidney disease combined with atherosclerosis （CKD AS） by regulating the phosphatidylinositol-3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR） signaling pathway and the mechanism of Shenshuai Xiezhuo decoction in the intervention of CKD AS rats with 5/6 nephrectomy combined with high-fat feeding. MethodA total of 60 SD rats were randomly divided into sham operation group， model group， losartan group， and low， medium， and high dose groups of Shenshuai Xiezhuo decoction. The CKD AS rat model was established by 5/6 nephrectomy combined with high-fat feeding for 10 weeks. The low， medium， and high dose groups （6.0， 12.0， 24.0 g·kg-1·d-1） of Shenshuai Xiezhuo decoction and the losartan group （20 mg·kg-1·d-1） were gavaged， and the corresponding intervention was carried out for eight weeks. Then， the rats were killed， and samples were collected for corresponding detection. Fully automated biochemical analyzers were used to detect kidney function and blood lipids in rats： blood creatinine （SCr）， blood urea nitrogen （BUN）， total cholesterol （TC）， triglyceride （TG）， and low-density lipoprotein cholesterol （LDL-C） levels. Hematoxylin-eosin （HE） and Masson staining of aortic tissue and pathological observation under a light microscope were carried out， and autophagosomes and autophagy lysosomes were observed by transmission electron microscopy. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to determine the mRNA levels of miRNA126， PI3K， Akt， and mTOR in rats， and Western blot was used to determine the protein expression levels of phosphorylated （p）-PI3K， PI3K， p-Akt， Akt， p -mTOR， mTOR， benzyl chloride 1 （Beclin-1）， and microtubule-associated protein light chain 3Ⅱ/Ⅰ （LC3Ⅱ/LC3Ⅰ）. ResultCompared with the sham operation group， the serum SCr， BUN， TC， TG， and LDL-C in the model group were significantly increased （P<0.01）. Compared with the model group， the SCr， BUN， TC， TG， and LDL-C were decreased in the losartan group and low， medium， and high dose groups of Shenshuai Xiezhuo decoction （P<0.05）. Compared with the sham operation group， thickening plaques， infiltration of mononuclear macrophages， a small number of foam cells， disordered arrangement of smooth muscle fibers in the tunica media， and increased collagen fibers were observed in the model group， and the lesions in the losartan group and Shenshuai Xiezhuo decoction groups were alleviated compared with those in the model group. Compared with the model group， the number of autophagosomes and autophagy lysosomes increased in the medium and high dose groups of Shenshuai Xiezhuo decoction. Compared with the sham operation group， the expression of miRNA126 in the aortic tissue of the model group was significantly decreased （P<0.01）， and the mRNA expressions of PI3K， Akt， and mTOR were significantly increased （P<0.01）. Compared with the model group， the expression of miRNA126 in the aortic tissue of rats in high， medium， and low dose groups of Shenshuai Xiezhuo decoction and losartan group was significantly increased （P<0.01）， while the mRNA expressions of PI3K， Akt， and mTOR were significantly decreased （P<0.01）. Compared with the sham operation group， the protein expressions of p-PI3K， PI3K， p-Akt， Akt， p-mTOR， and mTOR in the model group were significantly increased （P<0.01）， while the protein levels of Beclin-1， LC3Ⅰ， and LC3Ⅱ were significantly decreased （P<0.01）. Compared with the model group， the protein expressions of p-PI3K， PI3K， p-Akt， Akt， p-mTOR， and mTOR in the losartan group and low， medium， and high dose groups of Shenshuai Xiezhuo decoction were decreased （P<0.05）， while the protein levels of Beclin-1 and LC3Ⅱ/LC3Ⅰ were increased （P<0.05）. ConclusionThe expression of miRNA126 is decreased in the aortic tissue of CKD AS rats， and the PI3K/Akt/mTOR pathway is activated to inhibit autophagy flux. Shenshuai Xiezhuo decoction regulates the PI3K/Akt/mTOR signaling pathway through miRNA126， restores the autophagy of aortic endothelial cells， protects the damage of CKD vessels， reduces the formation of As plaques， and slows the development of cardiovascular complications.
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BACKGROUND: Preliminary study has prepared the three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold successfully.OBJECTIVE: To explore the mechanical properties, physical characteristics, chemical composition and antibiotic sustained-release ability of three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold loaded with levofloxacin. METHODS: Levofloxacin/chitosan (3:1) microspheres were constructed by emulsion settlement filter method. 5, 7.5 and 10 g of microspheres were added into 2％ of silk fibroin/chitosan/nano-hydroxyapatite mixed solution through freeze drying and chemical cross-linking to obtain the scaffolds loaded with antibiotics. The scaffolds loaded with antibiotics underwent scanning electron microscope observation, and chemical composition analysis. The sustained release, mechanical properties, porosity, water absorption expansion rate and hot water soluble loss rate were detected. RESULTS AND CONCLUSION: (1) Scanning electron microscope observed that there were drug microspheres at the inner wall of the scaffold, and the voidage was decreased with mass of microspheres increasing. (2) Energy spectrum analysis showed that the three kinds of scaffolds were rich in calcium and phosphonium ions. (3) The three kinds of scaffolds showed the same releasing trend, which presented with sudden-release effect at the former 3 days (release> 50％) , and then tended to be stable. The release rate was the slowest in the scaffold loaded with 10 g of microscopes, and the rapidest in the scaffold loaded with 5 g of microscopes. (4) With the mass of microspheres increasing, there was an increase in the compressive and tension abilities and hot water soluble loss rate, and a decrease in the porosity, mean pore size and water absorption expansion rate. (5) These results indicate that the three-dimensional tissue-engineered scaffold loaded with levofloxacin is constructed successfully by freeze drying and chemical cross-linking method, which holds good sustained-release effect and compressive ability, water absorption expansion rate and hot water soluble loss rate.
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BACKGROUND:Currently, there is a lack of efficient, non-invasive way to transplant stem cels to the target organ or tissue. Exploring a way to guide targeting transplantation of stem cels and to improve the efficiency of stem cel homing is now one of focuses in the field of stem cels research. OBJECTIVE: To establish a simple and feasible method to chemicaly modify the cel surface using biotin-streptavidin reaction system, and to evaluate the efficiency of this method to label bone marrow mesenchymal stem cels (BMSCs) and its effects on cel biological functions. METHODS: Passage 3 BMSCs were obtained by whole bone marrow culture method and verified by flow cytometry. Biotin, streptavidin, sulfonated biotin-N-hydroxy-succinimide were used to equip the adhesion molecule ligand, sialyated LewisX (SLeX), to the BMSCs surface. The labeling rate of BMSCs was assessed using fluorescence microscope, the vitality of BMSCs was evaluated by trypan blue staining, and the proliferation of BMSCs was evaluated by cel counting kit-8 assay. Adipogenic and osteogenic inductions were used to evaluate the effect of the method on the multi-differentiation function of BMSCs. RESULTS AND CONCLUSION: After culture for 2 weeks, passage 3 BMSCs were obtained and confirmed by expressing CD90, CD29 and lack of CD34, CD45. Biotin, streptavidin, sulfonated biotin-N-hydroxy-succinimide were successfuly used to equip sialyated LewisX (SLeX) to the BMSCs surface and had minor effects on the vitality, proliferation, and differentiation of BMSCs. This method was simple for surface modification and had a high modification rate of 88%. The homing of BMSCs modified by this method to the target organ or tissue could be greatly enhanced. Therefore, this method potentialy could have extensive and important applications.
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Objectives To study the efficacy of the two-compartment peritoneal dialysis fluid with low glucose degradation products in peritoneal dialysis (PD) patients.Methods Pubmed,EBMASE,Cochrane Library,Wanfang,VIP,CNKI,CBM and other databases were searched,at the same time the information form relevant literatures until December 2013 were searched by hand.To be eligible,studies had to be randomized controlled trials that allocated PD patients to two-compartment peritoneal dialysis fluid with low glucose degradation products (low-GPDs group) or to traditional dialysis fluid (control group).The qualities of included articles were assessed and then a meta-analysis was conducted by using RevMan 5.2 software.Results A total of 12 documents,11 studies met the inclusion criteria,and 1 059 cases were included.Meta-analysis results were as follows:(1)the low-GPDs group had higher level of CA125 in peritoneal dialysis effluent,higher residual renal function compared with that in the control group and the weighted mean difference were 19.61 (95％CI 12.04-27.18,P ＜ 0.01) and 0.78 (0.14-1.43,P=0.02),respectively; (2)There was no statistically significant difference between control and low-GPDs group in the ultrafiltration,peritonitis and plasma bicarbonate (all P ＞ 0.05); (3)Four studies showed no difference in peritoneal dialysis technique survival between the two group (P ＞ 0.05).Conclusions The two-compartment peritoneal dialysis fluid with low glucose degradation products is effective and safe,has no negative effects on the frequency of peritonitis,patient' s peritoneal member transport function and plasma bicarbonate,but it causes less mesothelial damage and has higher residual renal function in patients than conventional ones,and does not affect the technique survival time.