Expression of the sucrose transporter 3 (<Emphasis Type="Italic">HbSUT3</Emphasis>) in rubber tree and its relation to latex yield

Sucrose is not only a precursor of rubber biosynthesis, but it also participates in other latex regeneration between repeated tapping. Sucrose transporter (HbSUT) genes play key roles in sinks and sources of the rubber biosynthesis pathway. HbSUT3 was dominant in expression in latex among the SUT member genes. Therefore, the expression level of HbSUT3 in latex is a potential indicator distinguishing between high- and low-yielding clones. The aim of this research was to assess the potential of this gene in selective breeding to improve latex yield, from the correlation of HbSUT3 expression with latex yield. Four high-yielding clones were sampled in this study and compared with the common RRIM 600 clone as the baseline, paired by the field. Among the putative full-length cDNAs of Hevea sucrose transporters available in the NCBI database, only HbSUT3 was detected. The HbSUT3 gene was overexpressed in the four rubber clones relative to the control, and the NK1 clone had the highest expression level. The expression level of HbSUT3 correlated positively with latex yield but negatively with the sucrose content of latex. Gene expression analysis of rubber seedlings indicated that the bark had higher expression of this gene than the leaves, and the levels correlated with latex yields of these clones. These data provided new candidate selection criteria for use in the early selection of high-yielding rubber clones, necessary for rapid cycle breeding programs.     

Prospective evaluation of serum biomarker levels and cartilage repair by autologous chondrocyte transplantation and subchondral drilling in a canine model

Introduction

The purpose of this study was to evaluate serum chondroitin sulfate (CS) and hyaluronic acid (HA) levels and the capability of cartilage repair of full-thickness cartilage defects after treatment with two different fundamental surgical techniques: autologous chondrocyte transplantation (AC) and subchondral drilling (SD).

Methods

A 4-mm-diameter full-thickness cartilage defect was created in each of 10 skeletally mature male outbred dogs. The dogs were randomly separated into two groups. Groups A and B were treated with AC and SD, respectively. An evaluation was made at the 24th week of the experiment. Serum was analyzed prospectively – preoperatively and at 6-week intervals – for CS and HA levels by enzyme-linked immunosorbent assay (ELISA) and ELISA-based assays, respectively.

Results

The cartilage repair assessment score (median ± standard deviation) of group A (9.5 ± 2.5) was significantly higher than that of group B (2.5 ± 1.3) (P < 0.05). Group A also demonstrated a better quality of hyaline-like cartilage repair. Prospective analysis of serum WF6 and HA levels between the two groups did not show any significant difference. Serum WF6 levels at the 24th week of the experiment had a negative correlation (r = -0.69, P < 0.05) with the cartilage repair assessment score, whereas serum HA levels tended to correlate positively (r = 0.46, 0.1 <P < 0.05).

Conclusions

AC treatment provides superior results to SD treatment, according to morphology, histology, and cartilage marker levels. AC treatment demonstrated a smoother surface, less fissure, better border integration, and a more reliable outcome of repairing cartilage. Moreover, a decreasing level of serum WF6, which correlated with good quality of the repairing tissue at the end of the follow-up period, was found predominantly in the AC group. Serum WF6 therefore should be further explored as a sensitive marker for the noninvasive therapeutic evaluation of cartilage repair procedures.     

Rapid and massive virus-specific plasmablast responses during acute dengue virus infection in humans

Humoral immune responses are thought to play a major role in dengue virus-induced immunopathology; however, little is known about the plasmablasts producing these antibodies during an ongoing infection. Herein we present an analysis of plasmablast responses in patients with acute dengue virus infection. We found very potent plasmablast responses that often increased more than 1,000-fold over the baseline levels in healthy volunteers. In many patients, these responses made up as much 30% of the peripheral lymphocyte population. These responses were largely dengue virus specific and almost entirely made up of IgG-secreting cells, and plasmablasts reached very high numbers at a time after fever onset that generally coincided with the window where the most serious dengue virus-induced pathology is observed. The presence of these large, rapid, and virus-specific plasmablast responses raises the question as to whether these cells might have a role in dengue immunopathology during the ongoing infection. These findings clearly illustrate the need for a detailed understanding of the repertoire and specificity of the antibodies that these plasmablasts produce.     

Effects of different omega-3 sources,fish oil,krill oil,and green-lipped mussel against cytokine-mediated canine cartilage degradation

Our purpose was to evaluate the protective effect of three marine omega-3 sources, fish oil (FO), krill oil (KO), and green-lipped mussel (GLM) against cartilage degradation. Canine cartilage explants were stimulated with either 10 ng/mL interleukin-1β (IL-1β) or IL-1β/oncostatin M (10 ng/mL each) and then treated with various concentrations of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA; 3 and 30 μg/mL), FO, KO, or GLM (250, 500, and 1000 μg/mL) for 28 days. Gene expression was then investigated in primary canine chondrocytes. Our results showed that DHA and EPA as well as omega-3 sources could suppress matrix degradation in cytokine-induced cartilage explants by significantly reducing the increase of sulfated glycosaminoglycans (s-GAGs) and preserving uronic acid and hydroxyproline content (except GLM). These agents were not able to reduce IL-1β-induced IL1B and TNFA expression but were able to down-regulate the expression of the catabolic genes MMP1, MMP3, and MMP13 and up-regulate the anabolic genes AGG and COL2A1; FO and KO were especially effective. Our findings indicated that FO and KO were superior to GLM for their protective effect against proteoglycan and collagen degradation. Hence, FO and KO could serve as promising sources of chondroprotective agents.     

Expression of luciferase plasmid (pCMVLuc) entrapped in DPPC/Cholesterol/DDAB liposomes in HeLa cell lines

The luciferase gene expression of lipoplexes, a liposome containing luciferase plasmid (pCMVLuc), in HeLa cell lines, was investigated. Cationic liposomes were prepared by the chloroform film method with sonication. The lipoplex was formed by loading the liposome with pCMVLuc. The lipoplex with an optimal weight ratio of dimethyl dioctadecyl ammonium bromide (DDAB)/pCMVLuc protected from DNaseI was determined by an agarose gel electrophoresis. The selected lipoplexes were assayed for luciferaase activity by using a luminometer. The effect on cell proliferation was evaluated by WST-1 assay. The highest luciferase activity of 1.5 × 10⁶ RLU was observed in the cholesterol (Chol)/DDAB (2:1 molar ratio) lipoplex at the DDAB/pCMVLuc weight ratio of 10:1 at 48 hours, which was about 10, 100, and 1,000 times higher than the DDAB, L-alpha-dipalmitoyl phosphatidylcholine (DPPC)/Chol/DDAB (1:2:1 molar ratio), and DPPC/Chol/DDAB (2:2:1 molar ratio) lipoplexes, respectively. The liposome with the smallest particle size was obtained from the cationic liposome composed of DPPC/Chol/DDAB (7:1:1 molar ratio) with the ζ potential of 7.17 ± 0.73. The optimal weight ratio of DDAB/pCMVLuc that protected pCMVLuc from DNaseI digestion was 4:1 in the DDAB formulation. The Chol/DDAB (2:1 molar ratio) lipoplex with the DDAB/pCMVLuc of 10:1 showed the highest luciferase activity of 1.5 × 10⁶ RLU and the highest cytotoxicity as well. DPPC/Chol/DDAB (1:1:1 molar ratio)-lipoplex (DDAB/pCMVLuc = 14:1), which had the amount of DPPC and cholesterol not exceeding 33 and 50% mol, respectively, gave the lower gene expression of about 4 times, but lower cytoxicity of about 14 times, than the Chol/DDAB lipoplex (2:1 molar ratio) and was considered to be the most suitable formulation. The results from this study can be applied as a model for the development of a gene-therapeutic dosage form.