[Effects of Exenatide-4 on proliferation, migration and osteogenic differentiation of human periodontal ligament stem cells]

PURPOSE

To investigate the effects of exendin-4(EX-4) on proliferation, migration and osteogenic differentiation of human periodontal ligament stem cells(PDLSCs).

METHODS

PDLSCs were isolated and cultured using limited dilution method in vitro. Colony formation assay, osteogenic and adipogenic differentiation were applied to identify the stem cells. Immunofluorescence staining was used to detect the expression of EX-4 receptor glucagon-like peptide-1 receptor (GLP-1R) on the surface of PDLSCs. PDLSCs were stimulated with 5, 10, 20 or 50 nmol/L EX-4 in vitro. CCK-8, Transwell assay and alkaline phosphatase(ALP) activity assay were used to determine the effects of EX-4 on PDLSCs proliferation, migration and osteogenic differentiation. Quantitative real-time polymerase chain reaction was used to determine the expression of osteogenic related genes ALP, runt-related transcription factor 2(Runx2) and osteocalcin (OCN). The data were analyzed by Graphpad Prims 6.0 software package.

RESULTS

PDLSCs were successfully isolated and cultivated. GLP-1R positively expressed on the surface of PDLSCs. EX-4 exerted no significant effect on PDLSCs proliferation(P>0.05). EX-4 significantly promoted migration, ALP activity and osteogenic related genes expression of PDLSCs (P<0.05).

CONCLUSIONS

10 nmol/L EX-4 could promote migration and osteogenic differentiation of PDLSCs.

[Study on the characteristics of major birth defects in 1.69 million cases of fetus in Guangxi Zhuang Autonomous Region]

Objective: Tracking the information on 1.69 million fetal cases across Guangxi Zhuang Autonomous Region (Guangxi) so as to study the occurrences of total and major birth defects in order to evaluate the ability on related prevention and control programs in Guangxi. Methods: Using the self-developed "Gui Women's System" to establish a database of 1.69 million fetal cases in Guangxi and to analyze the distribution of time, space and population, as well as the outcomes of pregnancy, using the big data. Results: During the 29 months of observation, the overall live birth rate was 99.25%, with stillbirth rate during pregnancy as 0.44%, stillbirth rate during birth as 0.02%, and the 0-6 days mortality rate as 0.14%. The total detection rate on birth defects was 197.63/10 000; the incidence rate was 103.04/10 000, the birth rate was 102.55/10 000. The overall discovery rate of major birth defects was 48.33/10 000, with the incidence rate as 783 000, the birth rate as 0.58/10 000. The discovery rates of major birth defects in 14 cities were between 35 and 68/10 000, and the birth rate dropped significantly to less than 1.00 in 10 000. Nationalities showed that the number of pregnant women with birth defects more than 50 000 would include Hui (9.68/10 000), Yao (9.57/10 000), and Jing (9.37/10 000). With the increasing age of gestation, number of birth defects, incidence of major birth defects also increased. Ninety-five percent of the major birth defects were found within <28 weeks and with the top 5 kinds of major birth defects as complicated congenital heart disease (9.11/10 000), alpha thalassemia (8.36/10 000), and 21-trisomy syndrome (7.85/10 000), beta thalassemia (5.32/10 000) and fetal edema syndrome (4.92/10 000). The top 5 major birth defects appeared as complicated congenital heart disease (9.11/10 000), alpha thalassemia (8.36/10 000), and 21-trisomy syndrome (7.85/10 000), beta thalassemia (5.32/10 000) and fetal edema syndrome (4.92/10 000). Conclusion: Programs leading to increase the rate on discovery of major birth defects were fundamental in effectively reducing the major birth defects.

[Study on the distribution and related factors of birth weight of live births in Guangxi Zhuang Autonomous Region of China from 2016 to 2018]

Objective: To investigate the distribution and related factors of birth weight of live births and full-term infants in Guangxi Zhuang Autonomous Region of China. Methods: Based on Guangxi women and children information system from 2016 to 2018, a large real-time database about maternal and live-birth information was established. It covered 1 712 midwifery institutions in Guangxi. A total of 2 394 240 cases of live births were collected and 2 243 129 cases of which were full-term infants. The multivariate logistic regression model was used to analyze the related factors of low birth weight. Results: The birth weight of 2 394 240 live births, (3 123.49±461.08) g, in Guangxi was approximately normal distribution with a peak distribution to the left. The incidence of low birth weight was 8.05%, and the incidence of macrosomia was 2.07%. The incidence of low birth weight was 10.92% for the puerpera with body mass index (BMI, kg/m(2)) <18.5, 16.82% for the puerpera with height <145 cm, 8.92% for the puerpera with age <20 years old, 7.67% for the puerpera with age ≥35 years old, and 54.65% for the puerpera with premature birth. The birth weight of 2 243 129 full-term infants, (3 176.01±400.78) g, was approximately normal distribution with a peak distribution to the right. The incidence of low birth weight was 2.97%, and the incidence of macrosomia was 2.19%. The incidence of low birth weight was 4.73% for puerpera with BMI<18.5, 8.17% for puerpera with height<145 cm, 4.83% for puerpera with age <20 years old, and 3.05% for puerpera with age ≥35 years old. The risks of low birth weight [OR (95%CI) value] of pregnant women aged <20, 25-29 and 30-34 years old were 1.31 (1.28-1.35), 0.88 (0.86-0.90) and 0.89 (0.87-0.91) times of those aged ≥35 years old. The risks of low birth weight [OR (95%CI) value] of pregnancy BMI <18.5 and 18.5-23.9 kg/m(2) group were 1.98 (1.94-2.03) and 1.20 (1.18-1.23) times of those pregnancy BMI ≥24 kg/m(2). The risks of low birth weight [OR (95%CI) value] of pregnant women's height (cm)<145, 145-154, 155-159 and 160-164 cm were 4.67 (4.39-4.97), 2.36 (2.29-2.44), 1.58 (1.53-1.63) and 1.22 (1.18-1.26) times of those heights ≥165 cm group. The risks of low birth weight [OR (95%CI) value] of pregnant women's gestational age <28, 28-31 and 32-36 years old were 136.65 (124.33-150.20), 1 704.37 (1 509.02-1 925.02) and 33.45 (32.98-33.94) times of those gestational age ≥37 years old. Conclusion: The incidence of low birth weight of live births was higher in Guangxi from 2016 to 2018. There is a higher risk of low birth weight for younger, older, low height, low BMI and preterm women in Guangxi from 2016 to 2018.

Transcriptome analysis of chrysanthemum (Dendranthema grandiflorum) in response to low temperature stress

Background

Chrysanthemum is one kind of ornamental plant well-known and widely used in the world. However, its quality and production were severely affected by low temperature conditions in winter and early spring periods. Therefore, we used the RNA-Seq platform to perform a de novo transcriptome assembly to analyze chrysanthemum (Dendranthema grandiflorum) transcription response to low temperature.

Results

Using Illumina sequencing technology, a total of 86,444,237 high-quality clean reads and 93,837 unigenes were generated from four libraries: T01, controls; T02, 4 °C cold acclimation (CA) for 24 h; T03, − 4 °C freezing treatments for 4 h with prior CA; and T04, − 4 °C freezing treatments for 4 h without prior CA. In total, 7583 differentially expressed genes (DEGs) of 36,462 annotated unigenes were identified. We performed GO and KEGG pathway enrichment analyses, and excavated a group of important cold-responsive genes related to low temperature sensing and signal transduction, membrane lipid stability, reactive oxygen species (ROS) scavenging and osmoregulation. These genes encode many key proteins in plant biological processes, such as protein kinases, transcription factors, fatty acid desaturase, lipid-transfer proteins, antifreeze proteins, antioxidase and soluble sugars synthetases. We also verified expression levels of 10 DEGs using quantitative real-time polymerase chain reaction (qRT-PCR). In addition, we performed the determination of physiological indicators of chrysanthemum treated at low temperature, and the results were basically consistent with molecular sequencing results.

Conclusion

In summary, our study presents a genome-wide transcript profile of Dendranthema grandiflorum var. jinba and provides insights into the molecular mechanisms of D. grandiflorum in response to low temperature. These data contributes to our deeper relevant researches on cold tolerance and further exploring new candidate genes for chilling-tolerance and freezing-tolerance chrysanthemum molecular breeding.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4706-x) contains supplementary material, which is available to authorized users.

Overexpression of a chrysanthemum transcription factor gene DgNAC1 improves the salinity tolerance in chrysanthemum

DgNAC1, a transcription factor of chrysanthemum, was functionally verified to confer salt stress responses by regulating stress-responsive genes. NAC transcription factors play effective roles in resistance to different abiotic stresses, and overexpressions of NAC TFs in Arabidopsis have been proved to be conducive in improving salinity tolerance. However, functions of NAC genes in chrysanthemum continue to be poorly understood. Here, we performed physiology and molecular experiments to evaluate roles of DgNAC1 in chrysanthemum salt stress responses. In this study, DgNAC1-overexpressed chrysanthemum was obviously more resistant to salt over the WT (wild type). Specifically, the transgenic chrysanthemum showed a higher survival rate and lower EC (electrolyte conductivity) than WT under salt stress. The transgenic chrysanthemum also showed fewer accumulations of MDA (malondialdehyde) and reactive oxygen species (H₂O₂ and O₂^-), greater activities of SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase), as well as more proline content than WT under salt stress. Furthermore, stress-responsive genes in transgenic chrysanthemum were greater up-regulated than in WT under salinity stress. Thus, all results revealed that DgNAC1 worked as a positive regulator in responses to salt stress and it may be an essential gene for molecular breeding of salt-tolerant plants.

Overexpression of DgWRKY4 Enhances Salt Tolerance in Chrysanthemum Seedlings

High salinity seriously affects the production of chrysanthemum, so improving the salt tolerance of chrysanthemum becomes the focus and purpose of our research. The WRKY transcription factor (TF) family is highly associated with a number of processes of abiotic stress responses. We isolated DgWRKY4 from Dendranthema grandiflorum, and a protein encoded by this new gene contains two highly conserved WRKY domains and two C₂H₂ zinc-finger motifs. Then, we functionally characterized that DgWRKY4 was induced by salt, and DgWRKY4 overexpression in chrysanthemum resulted in increased tolerance to high salt stress compared to wild-type (WT). Under salt stress, the transgenic chrysanthemum accumulated less malondialdehyde, hydrogen peroxide (H₂O₂), and superoxide anion ([Formula: see text]) than WT, accompanied by more proline, soluble sugar, and activities of antioxidant enzymes than WT; in addition, a stronger photosynthetic capacity and a series of up-regulated stress-related genes were also found in transgenic chrysanthemum. All results demonstrated that DgWRKY4 is a positive regulatory gene responding to salt stress, via advancing photosynthetic capacity, promoting the operation of reactive oxygen species-scavenging system, maintaining membrane stability, enhancing the osmotic adjustment, and up-regulating transcript levels of stress-related genes. So, DgWRKY4 can serve as a new candidate gene for salt-tolerant plant breeding.

Comparative Analysis of the Chrysanthemum Leaf Transcript Profiling in Response to Salt Stress

Salt stress has some remarkable influence on chrysanthemum growth and productivity. To understand the molecular mechanisms associated with salt stress and identify genes of potential importance in cultivated chrysanthemum, we carried out transcriptome sequencing of chrysanthemum. Two cDNA libraries were generated from the control and salt-treated samples (Sample_0510_control and Sample_0510_treat) of leaves. By using the Illumina Solexa RNA sequencing technology, 94 million high quality sequencing reads and 161,522 unigenes were generated and then we annotated unigenes through comparing these sequences to diverse protein databases. A total of 126,646 differentially expressed transcripts (DETs) were identified in leaf. Plant hormones, amino acid metabolism, photosynthesis and secondary metabolism were all changed under salt stress after the complete list of GO term and KEGG enrichment analysis. The hormone biosynthesis changing and oxidative hurt decreasing appeared to be significantly related to salt tolerance of chrysanthemum. Important protein kinases and major transcription factor families involved in abiotic stress were differentially expressed, such as MAPKs, CDPKs, MYB, WRKY, AP2 and HD-zip. In general, these results can help us to confirm the molecular regulation mechanism and also provide us a comprehensive resource of chrysanthemum under salt stress.

Fracture of the patella treated by open reduction and external compressive skeletal fixation

Open reduction combined with external compressive skeletal fixation was used to treat twenty-seven patients who had a separated fracture of the patella. Fixation was obtained by the use of two compressive clamps applied to stainless-steel pins that were inserted just proximal and distal to the proximal and distal poles of the patella. Range-of-motion exercises for the knee were begun at two weeks and the pins were removed at three to four weeks. All of the fractures healed. Twenty-four patients regained a range of motion that was equal to that of the opposite knee. There was no evidence of chronic osteomyelitis. Osteoarthritis was noted in one patient who refused excision of a portion of the patella.