Transcriptome analysis of axillary buds in low phosphorus stress and functional analysis of TaWRKY74s in wheat.

BACKGROUND: Wheat is one of the main grain crops in the world, and the tiller number is a key factor affecting the yield of wheat. Phosphorus is an essential element for tiller development in wheat. However, due to decreasing phosphorus content in soil, there has been increasing use of phosphorus fertilizer, while imposing risk of soil and water pollution. Hence, it is important to identify low phosphorus tolerance genes and utilize them for stress resistance breeding in wheat. RESULTS: We subjected the wheat variety Kenong 199 (KN199) to low phosphorus stress and observed a reduced tiller number. Using transcriptome analysis, we identified 1651 upregulated genes and 827 downregulated of genes after low phosphorus stress. The differentially expressed genes were found to be enriched in the enzyme activity regulation related to phosphorus, hormone signal transduction, and ion transmembrane transport. Furthermore, the transcription factor analysis revealed that TaWRKY74s were important for low phosphorus tolerance. TaWRKY74s have three alleles: TaWRKY74-A, TaWRKY74-B, and TaWRKY74-D, and they all belong to the WRKY family with conserved WRKYGQK motifs. These proteins were found to be located in the nucleus, and they were expressed in axillary meristem, shoot apical meristem(SAM), young leaves, leaf primordium, and spikelet primordium. The evolutionary tree showed that TaWRKY74s were closely related to OsWRKY74s in rice. Moreover, TaWRKY74s-RNAi transgenic plants displayed significantly fewer tillers compared to wild-type plants under normal conditions. Additionally, the tiller numebr of the RNAi transgenic plants was also significantly lower than that of the wild-type plants under low-phosphorus stress, and increased the decrease amplitude. This suggestd that TaWRKY74s are related to phosphorus response and can affect the tiller number of wheat. CONCLUSIONS: The results of this research showed that TaWRKY74s were key genes in wheat response to low phosphorus stress, which might regulate wheat tiller number through abscisic acid (ABA) and auxin signal transduction pathways. This research lays the foundation for further investigating the mechanism of TaWRKY74s in the low phosphorus environments and is significant for wheat stress resistance breeding.

Chondrogenic differentiation of rabbit bone marrow mesenchymal stem cells induced by growth differentiation factor 5 / 中国组织工程研究

BACKGROUND:Growth differentiation factor 5 is a member of the transforming growth factor superfamily and one of the earliest markers of joint development.Growth differentiation factor 5 has an important role in cartilage repair. OBJECTIVE:To explore the action mechanism of growth differentiation factor 5-induced chondrogenic differentiation of bone marrow mesenchymal stem cells. METHODS:Rabbit bone marrow mesenchymal stem cells were isolated and cultured.CCK-8 assay was used to detect the effect of different mass concentrations of growth differentiation factor 5 on the proliferation activity of bone marrow mesenchymal stem cells.RT-PCR was utilized to detect the expression of genes related to chondrogenic differentiation of bone marrow mesenchymal stem cells induced by different mass concentrations of growth differentiation factor 5.To further investigate the action mechanism of growth differentiation factor 5-induced chondrogenic differentiation of bone marrow mesenchymal stem cells,we added inhibitor XAV-939 and activator Laduviglusib of Wnt/β-catenin signaling pathways to induce cell culture for 14 days.RT-PCR and western blot assay were performed to detect the expression of cartilage-related genes and Wnt/β-catenin signaling pathway proteins. RESULTS AND CONCLUSION:(1)CCK-8 results showed no significant effect of growth differentiation factor 5 on the proliferation of bone marrow mesenchymal stem cells.(2)Growth differentiation factor 5 promoted the expression of cartilage-related genes type Ⅱ collagen,aggrecan and Sox9,among which growth differentiation factor 5 induced a significant upregulation of cartilage-related genes in the 50 ng/mL group.(3)Addition of Laduviglusib,an activator of Wnt/β-catenin signaling pathway,upregulated Sox9,β-catenin and type Ⅱ collagen expression(P<0.05).Addition of XAV939,an inhibitor of Wnt/β-catenin signaling pathway,down-regulated Sox9,β-catenin and type Ⅱ collagen expression(P<0.05).(4)Taken together,growth differentiation factor 5-induced chondrogenic differentiation of bone marrow mesenchymal stem cells may be associated with the activation of the Wnt/β-catenin signaling pathway.

Preparation of collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold and its chondrogenic induction / 中国组织工程研究

BACKGROUND:Natural bone morphogenetic protein 2 disperses and degrades rapidly in vivo,reducing local concentration and therapeutic efficacy.Simply combining bone morphogenetic protein 2 with tissue engineering scaffolds could not stay in vivo for a long time,making it difficult to achieve good sustained and controlled release effects.OBJECTIVE:To prepare and test the biological properties and chondrogenic induction effect of collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold.METHODS:SD rat tail collagen was extracted and a collagen cartilage scaffold was prepared using a vacuum freeze-drying machine chemical crosslinking method.The plasmid expressing collagen-binding domain-bone morphogenetic protein 2 was constructed by rapid cloning C112 homologous recombination,constructed by genetic engineering,and introduced into E.coli,and then collagen-binding domain-bone morphogenetic protein 2 was isolated and purified.Natural bone morphogenetic protein 2 and collagen-binding domain-bone morphogenetic protein 2 were combined with collagen cartilage scaffolds,respectively,to detect the release level of bone morphogenetic protein 2 in the scaffolds.The biocompatibility of collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold was detected by CCK-8 assay and F-Actin staining.Bone marrow mesenchymal stem cells were implanted on two kinds of collagen cartilage scaffolds for chondrogenic induction,and their chondrogenic induction activity was tested.RESULTS AND CONCLUSION:(1)The binding rate of collagen-binding domain-bone morphogenetic protein 2 to collagen cartilage scaffolds was higher than that of natural bone morphogenetic protein 2(P<0.05).After being immersed in PBS for 7 days in vitro,the release of bone morphogenetic protein 2 in the collagen-binding domain bone morphogenetic protein 2-collagen cartilage scaffold was smaller than that in the natural bone morphogenetic protein 2-collagen cartilage scaffold(P<0.05).The results of the CCK-8 assay and F-Actin staining showed that the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold had no obvious cytotoxicity and had good biocompatibility.(2)After 14 days of chondrogenic induction,ELISA detection demonstrated that the expressions of agglutincan and type Ⅱ collagen A1 in the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold group were higher than those in the natural bone morphogenetic protein 2-collagen cartilage scaffold group(P<0.05).Under scanning electron microscopy,more bone marrow mesenchymal stem cells were observed on the inner wall of the pores of the two groups of scaffolds,and the cell morphology and size were the same,and the cells were closely arranged,without cell fragmentation or abnormal morphology.(3)The results indicate that the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold has good biological properties and chondrogenic induction activity.

Effects and problems of growth differentiation factor 5-induced multidirectional differentiation of mesenchymal stem cells / 中国组织工程研究

BACKGROUND:Growth differentiation factor 5,a member of the transforming growth factor-β superfamily and bone morphogenetic protein family,plays an important role in articular cartilage injury repair,bone regeneration,improvement of intervertebral disc degeneration,tendon healing,and neurodevelopment. OBJECTIVE:To review the research progress of growth differentiation factor 5 in inducing chondrocytes,nucleus pulposus-like cells,tendon cell differentiation,as well as inducing bone formation and neurodevelopment. METHODS:The search terms"growth differentiation factor 5,articular cartilage,bone,nucleus pulposus cells,tendon,nerve regeneration"were used in CNKI,WanFang and PubMed.According to the inclusion and exclusion criteria,the articles not related to the subject matter were excluded and 69 articles related to growth differentiation factor 5 were included. RESULTS AND CONCLUSION:(1)Growth differentiation factor 5 can induce chondrogenic and osteoblastic differentiation of mesenchymal stem cells,but the concentration boundary of growth differentiation factor 5 to induce chondrogenic or osteoblastic differentiation remains unclear.(2)Growth differentiation factor 5 can induce mesenchymal stem cells to differentiate into nucleus pulposus cells,which may play a role in the treatment of intervertebral disc degeneration.(3)Growth differentiation factor 5 can induce mesenchymal stem cells to differentiate into tendon cells and play an important role in tendon repair and prevention of postoperative tendon adhesion.(4)Growth differentiation factor 5 can induce neurodevelopment and promote nerve regeneration.

Repair of infected osteochondral defect with sustained release vancomycin three-dimensional scaffold in rabbits / 中国组织工程研究

BACKGROUND:A large number of studies have confirmed that tissue engineering scaffolds can almost completely repair osteochondral defects.However,when osteochondral defects are complicated with infection,even after thorough debridement in the early stage,the repair effect of simple osteochondral tissue engineering scaffolds is often unsatisfactory. OBJECTIVE:To prepare fibroin/chitosan/nano-hydroxyapatite scaffold loaded with vancomycin hydrochloride sustained release microspheres,and to investigate the repair effect on infected osteochondral defect in distal femur of rabbit. METHODS:(1)Vancomycin hydrochloride sustained release microspheres were prepared by emulsified solvent evaporation method.The sustained-release microspheres of different weights(7.5,10,and 12.5 mg)were mixed with fibroin protein-chitosan nanohydroxyapatite solution,and the scaffolds of fibroin protein/chitosan/nano-hydroxyapatite were prepared by chemical crosslinking method.The porosity,water absorption and expansion rate,hot water loss rate of the scaffolds,and drug sustained-release in vitro were characterized.(2)Forty-five New Zealand white rabbits were randomly divided into blank group,control group,and experimental group,with 15 rabbits in each group.The osteochondral defect and infection model of the distal femur of the right hind limb was established in both groups.The blank group was not treated,and the control group was implanted with fibroin protein-chitosan-nano-hydroxyapatite scaffold.Vancomycin hydrochloride sustained-release microspheres(10 mg)of fibroin/chitosan/nano-hydroxyapatite scaffold were implanted in the defect of the experimental group.The levels of C-reactive protein and leukocytes in blood samples were detected 1 week after operation.At 4,8 and 12 weeks after operation,the tissue of the operative area was taken for gross observation and pathological observation. RESULTS AND CONCLUSION:(1)With the increase of sustained-release microspheres content,the porosity of scaffolds decreased,and there was significant difference among groups(P＜0.05).There were no significant differences in the pore size,water absorption expansion rate and hot water loss rate among the three groups(P＞0.05).Vancomycin hydrochloride was released sustainably in vitro for more than 30 days in all three groups of scaffolds.(2)The levels of C-reactive protein and leukocytes in blood samples of the experimental group were lower than those of the blank group and control group(P＜0.05).The repair of gross cartilage in the experimental group was significantly better than that in the blank group and the control group.Hematoxylin-eosin,Masson,Alcian blue and type Ⅱ collagen immunohistochemical stainings showed that the osteochondral repair effect of the experimental group was significantly better than that of the blank group and the control group at each time point.(3)The results showed that fibroin/chitosan/nano-hydroxyapatite scaffolds loaded with vancomycin hydrochloride sustained-release microspheres could effectively promote the repair of open osteochondral defects.

Oxygen-Free Csp3-H Oxidation of Pyridin-2-yl-methanes to Pyridin-2-yl-methanones with Water by Copper Catalysis.

Aromatic ketones are important pharmaceutical intermediates, especially the pyridin-2-yl-methanone motifs. Thus, synthetic methods for these compounds have gained extensive attention in the last few years. Transition metals catalyze the oxidation of Csp3-H for the synthesis of aromatic ketones, which is arresting. Here, we describe an efficient copper-catalyzed synthesis of pyridin-2-yl-methanones from pyridin-2-yl-methanes through a direct Csp3-H oxidation approach with water under mild conditions. Pyridin-2-yl-methanes with aromatic rings, such as substituted benzene, thiophene, thiazole, pyridine, and triazine, undergo the reaction well to obtain the corresponding products in moderate to good yields. Several controlled experiments are operated for the mechanism exploration, indicating that water participates in the oxidation process, and it is the single oxygen source in this transformation. The current work provides new insights for water-involving oxidation reactions.

[Contamination and Probabilistic Health Risk Assessment of Heavy Metals in Agricultural Soils Around a Lead-Zinc Smelter].

In order to identify the contamination and health risks of heavy metals in agricultural soils, a total of 56 surface soil samples (0-20 cm) were collected around a Pb-Zn smelter in Yunnan Province, and six heavy metals (Pb, Cd, Zn, As, Cu, and Hg) and pH were analyzed to assess heavy metal status, ecological risk, and probabilistic health risk. The results revealed that the average contents of six heavy metals (Pb:4413.93 mg·kg-1, Cd:6.89 mg·kg-1, Zn:1672.76 mg·kg-1, As:44.45 mg·kg-1, Cu:47.61 mg·kg-1, and Hg:0.21 mg·kg-1) were higher than their background values in Yunnan Province. Cd had the highest mean geo-accumulation index (Igeo) of 0.24, the highest mean pollution index (Pi) of 30.42, and the greatest average ecological risk index (Er) of 1312.60, indicating that Cd was the primary enriched and highest-ecological risk pollutant. The mean hazard index (HI) through exposure to six HMs was 2.42E-01 and 9.36E-01 for adults and children, respectively, with 36.63% of HI values for children exceeding the risk threshold of 1. Moreover, the mean total cancer risks (TCR) were 6.98E-05 and 5.93E-04 for adults and children, respectively, with 86.85% of TCR values for children exceeding the guideline value of 1E-04. The probabilistic health risk assessment suggested that Cd and As were the main contributors for the non-carcinogenic risks and carcinogenic risks. This work will provide scientific reference for the precise risk management and effective remediation strategy of soil heavy metal pollution in this study area.

Reducing expression of TaOTUB1s decreases tiller number in wheat.

Tiller number is an important agronomic trait that affects crop yield. The roles of OTUB1 in regulating tiller numbers in rice have been reported. However, the roles of OTUB1 in wheat remain elusive. In this study, TaOTUB1s were identified in wheat. TaOTUB1 proteins were localized in the nucleus and cytoplasm. Compared with wild-type Fielder, TaOTUB1-RNAi transgenic wheat plants had fewer tillers. Similar to OTUB1 in rice, the yeast double hybrid indicated that the TaOTUB1-A protein could interact with TaSPL17 and TaUBC13 proteins. The results of quantitative real-time polymerase chain reaction revealed that the expression levels of TaOTUB1s decreased while those of TaSPL17 significantly improved in TaOTUB1-RNAi lines. These findings suggested that TaOTUB1s influenced tiller number in wheat.

Candidate region aware nested named entity recognition.

Named entity recognition (NER) is crucial in various natural language processing (NLP) tasks. However, the nested entities which are common in practical corpus are often ignored in most of current NER models. To extract the nested entities, two categories of models (i.e., feature-based and neural network-based approaches) are proposed. However, the feature-based models suffer from the complicated feature engineering and often heavily rely on the external resources. Discarding the heavy feature engineering, recent neural network-based methods which treat the nested NER as a classification task are designed but still suffer from the heavy class imbalance issue and the high computational cost. To solve these problems, we propose a neural multi-task model with two modules: Binary Sequence Labeling and Candidate Region Classification to extract the nested entities. Extensive experiments are conducted on the public datasets. Comparing with recent neural network-based approaches, our proposed model achieves the better performance and obtains the higher efficiency.

Prevalence rate of non-obese fatty liver disease and related influencing factors / 临床肝胆病杂志

Objective To investigate the prevalence rate of non-obese fatty liver disease and its influencing factors, and to provide a reference for the prevention and treatment of fatty liver disease. Methods A total of 23 545 individuals who underwent physical examination in Karamay Central Hospital from January to December 2015 and had complete data of abdominal ultrasound, body mass index (BMI), age, and sex were screened out to analyze the prevalence rate of fatty liver disease, and 7484 individuals with normal BMI who had complete data of triglyceride (TG), fasting blood glucose, and alanine aminotransferase (ALT) were further screened out to perform a multivariate analysis. The t -test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between groups. A multivariate logistic regression analysis was performed to investigate independent influencing factors for non-obese fatty liver disease. Results In 2015, the prevalence rate of fatty liver disease was 30.2% (7116/23 545) among the individuals who underwent physical examination in Karamay Central Hospital. A stratified analysis based on BMI showed that the individuals with emaciation, normal BMI, overweight, and obesity had a prevalence rate of 0.8% (6/706), 9.3% (919/9899), 38.4% (3404/8870), and 68.5% (2787/4070), respectively (all P 0.05), while both of them had a significantly higher prevalence rate than the young individuals (14.5%/16.8% vs 6.0%, P < 0.05). Young and middle-aged male individuals had a significantly higher prevalence rate of fatty liver disease than their female counterparts ( χ 2 =99.40 and 43.29, both P < 0.001), while the elderly male individuals had a significantly lower prevalence rate than their female counterparts ( χ 2 =9.81, P =0.002). For the individuals with normal BMI, the individuals with normal TG had a prevalence rate of fatty liver disease of 5.0% (311/6273), while those with elevated TG had a prevalence rate of 26.8% (325/1211), with a significant difference between the two groups ( χ 2 =624.90, P < 0.001). The multivariate logistic regression analysis showed that age, BMI, ALT, fasting blood glucose, TG, and serum uric acid level were independent influencing factors for fatty liver disease in individuals with normal BMI (all P < 0.001). Conclusion There is a relatively high prevalence rate of non-obese fatty liver disease among individuals undergoing physical examination in Karamay Central Hospital, and 61.5% of the patients with non-obese fatty liver disease have glucose or lipid metabolic disorders. Serum TG level may be used as a simple and effective screening index for non-obese fatty liver disease.

Prevalence and risk factors of chronic kidney disease and diabetic kidney disease in a central Chinese urban population: a cross-sectional survey.

BACKGROUND: This study was conducted to evaluate and update the current prevalence of and risk factors for chronic kidney disease (CKD) and diabetic kidney disease (DKD) in a central Chinese urban population. METHODS: From December 2017 to June 2018, a total of 5231 subjects were randomly enrolled from 3 communities in 3 districts of Zhengzhou. CKD was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min.1.73m2 or urinary albumin to creatinine ratio ≥ 30 mg/g (albuminuria). Diabetic subjects with systolic blood pressure > 140 mmHg, albuminuria or an eGFR less than 60 mL/min/1.73 m2 were classified as having DKD. Participants completed a questionnaire assessing lifestyle and relevant medical history, and blood and urine specimens were taken. Serum creatinine, uric acid, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein and urinary albumin were assessed. The age- and sex-adjusted prevalences of CKD and DKD were calculated, and risk factors associated with the presence of reduced eGFR, albuminuria, DKD, severity of albuminuria and progression of reduced renal function were analyzed by binary and ordinal logistic regression. RESULTS: The overall adjusted prevalence of CKD was 16.8% (15.8-17.8%) and that of DKD was 3.5% (3.0-4.0%). Decreased renal function was detected in 132 participants (2.9, 95% confidence interval [CI]: 2.5-3.2%), whereas albuminuria was found in 858 participants (14.9, 95% CI: 13.9-15.9%). In all participants with diabetes, the prevalence of reduced eGFR was 6.3% (95% CI = 3.9-8.6%) and that of albuminuria was 45.3% (95% CI = 40.4-50.1%). The overall prevalence of CKD in participants with diabetes was 48.0% (95% CI = 43.1-52.9%). The results of the binary and ordinal logistic regression indicated that the factors independently associated with a higher risk of reduced eGFR and albuminuria were older age, sex, smoking, alcohol consumption, overweight, obesity, diabetes, hypertension, dyslipidemia and hyperuricemia. CONCLUSIONS: Our study shows the current prevalence of CKD and DKD in residents of Central China. The high prevalence suggests an urgent need to implement interventions to relieve the high burden of CKD and DKD in China.

TaD27-B gene controls the tiller number in hexaploid wheat.

Tillering is a significant agronomic trait in wheat which shapes plant architecture and yield. Strigolactones (SLs) function in inhibiting axillary bud outgrowth. The roles of SLs in the regulation of bud outgrowth have been described in model plant species, including rice and Arabidopsis. However, the role of SLs genes in wheat remains elusive due to the size and complexity of the wheat genomes. In this study, TaD27 genes in wheat, orthologs of rice D27 encoding an enzyme involved in SLs biosynthesis, were identified. TaD27-RNAi wheat plants had more tillers, and TaD27-B-OE wheat plants had fewer tillers. Germination bioassay of Orobanche confirmed the SLs was deficient in TaD27-RNAi and excessive in TaD27-B-OE wheat plants. Moreover, application of exogenous GR24 or TIS108 could mediate the axillary bud outgrowth of TaD27-RNAi and TaD27-B-OE in the hydroponic culture, suggesting that TaD27-B plays critical roles in regulating wheat tiller number by participating in SLs biosynthesis. Unlike rice D27, plant height was not affected in the transgenic wheat plants. Transcription and gene coexpression network analysis showed that a number of genes are involved in the SLs signalling pathway and axillary bud development. Our results indicate that TaD27-B is a key factor in the regulation of tiller number in wheat.

Preparation of progressive gradient-aperture osteochondral scaffold and its cytocompatibility evaluation / 中华老年医学杂志

Objective:To prepare a progressive gradient-aperture scaffold composed of silk fibroin(SF)-chitosan(CS)-nano-hydroxyapatite(nHAp)for osteochondral repair.Method:The SF solution, CS solution and nHA suspension were mixed in vitro at equal proportions.The progressive gradient osteochondral(OC)scaffold-1(2%), scaffold-2(3%)and scaffold-3(4%)was respectively prepared by using centrifugation, vacuum freeze-drying, chemical cross-linking and three shaping steps.General conditions, porosity, hot water dissolution rate, water swelling rate, compression water swelling rate, water swelling rate after dissolution, mechanical properties, internal structure observation and pore size were measured.Rat bone marrow mesenchymal stem cells(BMSCs)were cultured and the scaffold extract was prepared.The effect of scaffold extract on the proliferation of BMSCs was detected by the cell counting kit-8(CCK-8)method.BMSCs were co-cultured with the scaffold, and the distribution and morphology of the cells around the scaffold were observed.Results:The structure of scaffold was regular in each group and the porosity was more than 80%.Along with the increase of the material concentration, the water swelling rate of the scaffold was decreased gradually( P<0.05). Compared with before compression, the water swelling rate of scaffold-1 was decreased after compression( P<0.05). There was no significant difference in the hot water dissolution rate among all groups( all P>0.05), and the complete dissolution of the scaffold-1, scaffold-2 and scaffold-3 in vitro required 65.9, 60.9, and 73.9weeks, respectively.The elastic modulus of scaffolds in above three groups were 0.0955, 0.1762 and 0.3468 MPa, respectively.The examination results of scanning electron microscope(SEM)showed that the internal structure of scaffold was honeycomb in each group, the pore shape was regular, which showed an inter-connected pore network.The pore distribution was gradually dense and the pore diameter gradually decreased from the cartilage side to the osteogenic side( P<0.05), and the nHAp content increased gradually.The scaffold extract had no obvious toxicity to the growth and proliferation of BMSCs in each group.After BMSCs were seeded on scaffolds and co-cultured for 5 days, the cells grew well without obvious cell death or morphological abnormalities. Conclusions:In this study, a progressive gradient pore size OC scaffold is successfully prepared with good physical properties and biocompatibility, which is expected to be a new bio-mimetic composite scaffold material for repairing OC defects.

Silencing of long noncoding RNA PVT1 inhibits podocyte damage and apoptosis in diabetic nephropathy by upregulating FOXA1.

The number of patients with diabetic nephropathy (DN) is still on the rise worldwide, and this requires the development of new therapeutic strategies. Recent reports have highlighted genetic factors in the treatment of DN. Herein, we aimed to study the roles of long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) and histone 3 lysine 27 trimethylation (H3K27me3) in DN. A model of DN was established by inducing diabetes in mice with streptozotocin. Mouse podocyte clone 5 (MPC5) podocytes and primary podocytes were cultured in normal and high glucose media to observe cell morphology and to quantify PVT1 expression. The roles of PVT1 and enhancer of zeste homolog 2 (EZH2) were validated via loss-of-function and gain-of-function in vitro experiments to identify the interactions among PVT1, EZH2, and forkhead box A1 (FOXA1). The podocyte damage and apoptosis due to PVT1 and FOXA1 were verified with in vivo experiments. PVT1 was highly expressed in MPC5 and primary podocytes in DN patients and in cultures grown in high glucose medium. A large number of CpG (C-phosphate-G) island sites were predicted at the FOXA1 promoter region, where PVT1 recruited EZH2 to promote the recruitment of H3K27me3. The silencing of PVT1 or the overexpression of FOXA1 relieved the damage and inhibited the apoptosis of podocytes in DN, as was evidenced by the upregulated expression of synaptopodin and podocin, higher expression of Bcl-2, and lower expression of Bax and cleaved caspase-3. The key findings of this study collectively indicate that the suppression of lncRNA PVT1 exerts inhibitory effects on podocyte damage and apoptosis via FOXA1 in DN, which is of clinical significance.

Polylactic acid/polyglycolic acid copolymer scaffolds carrying bone morphogenetic protein 2 gene enhanced adipose-derived stem cells promote cartilage defect repair / 中国组织工程研究

BACKGROUND:Gene-enhanced tissue engineering can promote the proliferation and differentiation of seed cells,reduce allogeneic immunity,promote vascularization,and facilitate the repair of osteochondral defects.OBJECTIVE:To observe the effect of lentivirus-mediated human bone morphogenetic protein-2 (BMP-2) transfected rebbit adipose-derived stem cells (ADSCs) cultured on polylactic acid/polyglycolic acid copolymer scaffold (PLGA) on osteochondral defect repair.METHODS:Thirty male New Zealand rabbits were randomly divided into control group (n=15) and experimental group (n=15).Animal models of bilateral femoral cartilage defects were made in all rabbits.The experimental group was implanted with BMP-2-enhanced ADSCs/PLGA copolymer scaffold,and the control group was implanted with ADSCs/PLGA copolymer scaffold.In both groups,autologous osteochondral mosaicplasty was then performed.After 3 months of implantation,bone tissues at defect region were taken for biomechanical and proteoglycans detection.Histological observation was done at 3,6,12 months after implantation.RESULTS AND CONCLUSION:(1) The compressive modulus and proteoglycan content of the experimental group were significantly higher than those of the control group at 3 months after implantation (P ＜ 0.01).(2) At 3,6 and 12 months after implantation,with the increase of postoperative time,the joint surface in the experimental group became more and more smooth,the color became more and more shallow,and the healing degree of the defect increased to different extent.However,there were no obvious changes in the joint surface,color,morphology and histomorphology in the control group.To conclude,BMP-2-enhanced ADSCs/PLGA copolymer scaffold could significantly promote the repair of osteochondral defects.

A preliminary study on the fabrication of silk fibroin/chitosan/nano-hydroxyapatite osteochondral scaffolds with a gradient pore size structure / 中华老年医学杂志

Objective To explore the feasibility and methods of preparing silk fibroin(SF)/ chitosan(CS)/nano hydroxyapatite(nHA)composite osteochondral scaffolds with a gradient pore size structure.Methods We prepared an SF solution,a CS solution and an nHA suspension,all with a 2％ concentration,and mixed them with equal proportions.The mixture was used to prepare SF/CS/nHA composite osteochondral scaffolds with a pore size gradient through a centrifugal freeze drying and chemical cross linking method.The porosity,hot water loss rate,water swelling rate and mechanical properties of the scaffold were measured,and the dissolution curve and stress strain curve were drawn.The internal structure and morphology of the scaffold were observed by scanning electron microscopy(SEM)and the sizes of pores in the scaffold were measured.Results The porosity of the scaffold was(91.30± 3.35)％;The five week hot water loss rate was(16.57± 3.18)％;And the water swelling rate was (3218.53 ± 84.37)％.Mechanical test results demonstrated a good compression performance of the scaffold.SEM showed that the internal pores of the scaffolds were honeycomb structured with communicating passages;The density of pores gradually increased with decreasing pore sizes from the top to the bottom(pore sizes at four different levels:(141.11± 11.85)μm,(119.94± 9.05)μm,(93.10 ± 14.98) μm,and (79.95 ± 8.65)μm,respectively,F =22.973,P =0.000).Scaffold cytotoxicity test results indicated no significant difference between A values of the extract group and of the negative control group at any time point(t24 h =0.520,P =0.610;t48 h =0.665,P =0.515;t72 h =0.439,P =0.666),and all RGR values were greater than 100％.Conclusions SF/CS/nHA composite osteochondral scaffolds with a gradient pore size structure can be prepared with a centrifugal-freeze drying and chemical cross-linking method.Scaffolds prepared this way have a three-dimensional structure,a gradient pore size structure,high porosity,strong water absorption,suitable degradation rates and good compressive resistance.Besides,the good cell compatibility and low cytotoxicity of the scaffolds satisfy the requirements for osteochondral tissue engineering materials.

Preparation of silk fibroin/chitosan/nano-hydroxyapatite scaffold for sustained release of bone morphogenetic protein-2 / 中国组织工程研究

BACKGROUND:Bone morphogenetic protein-2 (BMP-2) is a key to bone formation and repair.However,it has some disadvantages such as easy to lose and degrade and difficult to sustain continuous effect.OBJECTIVE:To study the preparation and properties of silk fibroin/chitosan/nano-hydroxyapatite (SF/CS/nHA) scaffold loading BMP-2.METHODS:After silk degumming,dissolution and purification,2％ SF solution was obtained.BMP-2 was dissolved in 2％ CS solution,and then fully mixed with equal volume of SF solution and proper amount of nHA.At last,the SF/CS/nHA scaffold loading BMP-2 was prepared using freeze-drying method as experimental group.The SF/CS/nHA scaffold was soaked in the BMP-2 solution as control group.The scaffold porosity was measured by Archimedes method,the surface morphology of the scaffold was observed by scanning electron microscope,the compressive strength was measured by universal testing machine.Scaffolds in the two groups were soaked in PBS,and the release of BMP-2 was measured by ELISA method at different time points.RESULTS AND CONCLUSION:(1) The scaffolds in the two groups had irregular porous structure,interconnected pores and uneven pore wall.There was no significant difference between the two groups in mean pore diameter,porosity and maximum compressive strength.(2) On the 1st day,the release rate of BMP-2 was 4.63％ in the experimental group,and the release curve increased slowly.After 28 days,the release curve of BMP-2 was transferred to the plateau stage.But in the control group,the release rate of BMP-2 on the 1stday was 58.84％,and it was a significant initial burst release.The release curve increased rapidly,and was transferred to the platform stage on the 10th day.The release rate of BMP-2 release was significantly different between the two groups at days 1,2,4,10 (P ＜ 0.05).These results show that the SF/CS/nHA scaffold loading BMP-2 could sustainably and slowly release BMP-2.

Effect of temperature and humidity on blood quality of whole blood of emergency blood collection / 军事医学

Objective To study the effects of environmental factors,including high temperature,high humidity and low temprtature,on the quality of whole blood.Methods Fresh blood was collected from 9 blood donors and divided into 40 parts.One group that comprised 20 samples was used to assess the effects of storage at high temperature and high humidity (0,3,6,12 and 24 h),and the other group(20 samples)was used to determine the effects of low temprtature(0,1,2 and 3 h).The serum free hemoglobin(FHb)concentration, plasma prothrombin time(PT), activated partial thromboplastin time(APTT),thrombin time(TT)and fibrinogen(FIB)were measured and analyzed.Results The high temperature(27-37℃)and humidity(60%-90%RH)had no effect on FHb, PT, APTT, TT or FIB of whole blood. The low temperature(0-13℃and -18--20℃)had some effect on the quality of whole blood.The FHb of test group was higher than that of control group.There was no significant difference in PT, APTT, TT and FIB between the two groups.Conclusion Under high temperature and humidity conditions, 24 hours of whole blood placement is feasible. Under low temperature or cold conditions,short-term whole blood placement is feasible in a tent with heating facilities.

Bone mineral density decreased is a high risk factor for uncemented acetabular cups migration in female total hip arthroplasty patients / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the decrease of bone mineral density in female patients, effects on acetabular displacement.</p><p><b>METHODS</b>From October 2013 to November 2015, a total of 34 patients underwent total hip replacement in the Department of orthopedics, the Third Affiliated Hospital of Zunyi Medical College. The two groups of patients were female and the patients were treated with hip osteoarthritis. Based on the lowest value of preoperative dual energy X-ray bone mineral density (DXA), the patients were divided into normal group and low bone mineral density(-3.5<=T<=-1). There were 10 patients in the normal group, ranging in age from 55 to 64 years old, with an average of (58.00±4.22) years old. There were 24 patients in the low bone density group, ranging in age from 58 to 72 years old, with an average age of (65.71±8.19) years old. All the patients received a THA implant with ceramic-on-ceramic bearings(Depuy America). The lining system was Pinnacle cup. During the operation, the acetabular cup was maintained at abduction 45 degree and anteversion 15 degree. Analysis (RSA) of acetabular components in 3, 6, 12, and 24 months after surgery.</p><p><b>RESULTS</b>There was a statistically significant difference in cup migration between patients with normal BMD and those with low BMD. At 3 months, compare to the normal group, the low bone mineral density (BMD) occurred in the X axis (95% confidence interval, 0.01 to 0.31;=0.006) and Y (95% confidence interval 0.20 to 0.39;=0.003). The initial rotation occurs in a separate Z axis(95% confidence interval -0.26 to 0.81;=0.006).</p><p><b>CONCLUSIONS</b>It has produced that increaseed migration of uncemented cups in female patients with low systemic BMD in 3 months after surgery.</p>

HCMV-encoded miRNA during latent infection / 军事医学

Objective To explore humam cytomegalovirus(HCMV) encoded microRNAs during latent infection in order to help study HCMV virology and latent infection mechanisms.Methods A model of HCMV latent infection via THP-1 cells infected with HCMV was constructed.Deep-sequencing was performed using high-resolution Solexa sequencing platform.The secondary structure of the newly sequenced miRNA was predicted by RNAFold bioinformatics software. Results HCMV encoded various miRNAs during latent infection, including miR-US25-2-3p, miR-US25-2-5p, miR-UL112, miR-US25-1, miR-UL22A and PC-5p-148467 with a predicted length of 25 bp, named hcmv-miR-US33as-5p.Conclusion HCMV can express many types of miRNAs during latent infection.