Localization of a beta-crystallin gene, Hu beta A3/A1 (gene symbol: CRYB1), to the long arm of human chromosome 17

We have assigned a human beta-crystallin gene, Hu beta A3/A1 (gene symbol: CRYB1), to chromosome 17 using a panel of 19 human-hamster somatic cell hybrids and blot-hybridization analysis of cell hybrid DNA. Positive probe-hybridization signal was detected in a hybrid that had lost the short arm of human chromosome 17 but retained the long arm, translocated to a hamster chromosome. In addition, in situ hybridization analysis of metaphase chromosome spreads of this cell line suggested that the most probable location for CRYB1 is on the long arm of chromosome 17, in the region q21.     

Elucidation of 2-hydroxybiphenyl effect on dibenzothiophene desulfurization by Microbacterium sp. strain ZD-M2

The effect of 2-hydroxybiphenyl (2-HBP), the end product of dibenzothiophene (DBT) desulfurization via 4S pathway, on cell growth and desulfurization activity was investigated by Microbacterium sp. The experimental results indicate that 2-HBP would inhibit the desulfurization activity. Providing 2-HBP was added in the reaction media, the DBT degradation rate decreased along with the increase of 2-HBP addition. By contrast, cell growth would be promoted in the addition of 2-HBP at a low concentration (<0.1mM). At high concentration of 2-HBP, the inhibition on the cell growth occurred. Meanwhile, the inhibitory effect of 2-HBP on DBT desulfurization activity was tested both in the oil/aqueous two-phase system and the aqueous system. A mathematical model was developed to explain the product formation kinetics with DBT as the sole sulfur source. The predicted results were close to the experimental data, it elucidated that along with the 2-HBP accumulation, the inhibitory effect of 2-HBP on DBT desulfurization and cell growth was enhanced.     

Effect of substrate stiffness on proliferation and differentiation of periodontal ligament stem cells

Objectives

The aim of this study was to understand the effect of substrate stiffness (a mechanical factor of the extracellular matrix) on periodontal ligament stem cells (PDLSCs) and its underlying mechanism.

Materials and methods

Elastic substrates were fabricated by mixing 2 components, a base and curing agent in proportions of 10:1, 20:1, 30:1 or 40:1. PDLSC morphology was observed using scanning electron microscopy (SEM). Cell proliferation and differentiation were assessed after PDLSCs was cultured on various elastic substrates. Data were analysed using one‐way ANOVA.

Results

SEM revealed variations in the morphology of PDLSCs cultured on elastic substrates. PDLSC proliferation increased with substrate stiffness (P < .05). Osteogenic differentiation of PDLSCs was higher on stiff substrates. Notch pathway markers were up‐regulated in PDLSCs cultured on stiff substrates.

Conclusions

Results suggested that the osteogenic differentiation of PDLSCs might be promoted by culturing them in a stiffness‐dependent manner, which regulates the Notch pathway. This might provide a new method of enhancing osteogenesis in PDLSCs.

     

MicroRNAs are dynamically regulated and play an important role in LPS-induced lung injury

Acute lung injury is characterized by an increase of inflammatory reaction and severe lung edema. Even if there have been great advances in the identification of genes and signaling pathways involved in acute lung injury, the fundamental mechanisms of initiation and propagation of acute lung injury have not been understood completely. A growing amount of evidence indicates that microRNAs (miRNAs) are involved in various human diseases. However, the expression profile and function of miRNAs in acute lung injury have not been investigated. Here, using real-time polymerase chain reaction analysis, we show that a collection of miRNAs is dynamically regulated in lipopolysaccharide (LPS)-induced mouse acute lung injury. Among them, miR-199a and miR-16 are the most significantly down-regulated miRNAs. To study the role of miR-199a and miR-16 in acute lung injury, an over-expression of miR-199a or miR-16 assay was performed in LPS-treated A549 cells, and then the expression of inflammatory factors was analyzed. Over-expression of miR-199a could not alter the expression level of interleukin (IL)-6 and tumor necrosis factor-alpha (TNFα), while up-regulation of miR-16 could significantly down-regulate IL-6 and TNFα expression level. Using bioinformatic analysis, we show that a 3' untranslational region (UTR) of IL-6 and TNFα contains the binding sites of miR-16. Accordingly, over-expression of miR-16 could significantly suppress the luciferase activity of reporter fusion with the binding sites of TNFα in its 3'UTR region, suggesting that miR-16 played its role in LPS-induced lung inflammation by a direct manner. In this study, we show for the first time that miRNAs are dynamically regulated and play an important function in LPS-induced lung injury.     

Protective effects of activated vitamin D receptor on radiation‐induced intestinal injury

Radiation‐induced intestinal injury (RIII) is a common complication after radiation therapy in patients with pelvic, abdominal, or retroperitoneal tumours. Recently, in the model of DSS (Dextran Sulfate Sodium Salt) ‐induced intestinal inflammatory injury, it has been found in the study that transgenic mice expressing hVDR in IEC (Intestinal Epithelial Cell) manifest highly anti‐injury properties in colitis, suggesting that activated VDR in the epithelial cells of intestine may inhibit colitis by protecting the mucosal epithelial barrier. In this study, we investigated the effect of the expression and regulation of VDR on the protection of RIII, and the radiosensitivity in vitro experiments, and explored the initial mechanism of VDR in regulating radiosensitivity of IEC. As a result, we found that the expression of VDR in intestinal tissues and cells in mice can be induced by ionizing radiation. VDR agonists are able to prolong the average survival time of mice after radiation and reduce the radiation‐induced intestinal injury. For lack of vitamin D, the radiosensitivity of intestinal epithelial cells in mice increased, which can be reduced by VDR activation. Ensuing VDR activation, the radiation‐induced intestinal stem cells damage is decreased, and the regeneration and differentiation of intestinal stem cells is promoted as well. Finally, on the basis of sequencing analysis, we validated and found that VDR may target the HIF/PDK1 pathway to mitigate RIII. We concluded that agonism or upregulation of VDR expression attenuates radiation‐induced intestinal damage in mice and promotes the repair of epithelial damage in intestinal stem cells.     

Construction of a high density integrated genetic map for cucumber (Cucumis sativus L.)

The high-density consensus map was constructed based on the GY14 × PI 183967 map from an inter-subspecific cross and the extended S94 × S06 map from an intra-subspecific cross. The consensus map was composed of 1,369 loci, including 1,152 SSR loci, 192 SRAP loci, 21 SCAR loci and one STS locus as well as three gene loci of fruit external quality traits in seven chromosomes, and spanned 700.5 cM, of which 682.7 cM (97.5%) were covered by SSR markers. The average genetic distance and physical interval between loci were 0.51 cM and ~268 kbp, respectively. Additionally, the physical position of the sequence-associated markers aligned along the assembled cucumber genome sequence established a relationship between genetic maps and cucumber genome sequence and to a great extent validated the order of markers in individual maps and consensus map. This consensus map with a high marker density and well-ordered markers is a saturated and reliable linkage map for genetic analysis of cucumber or the Cucurbitaceae family of plants.     

Increase of anti-HIV activity of C-peptide fusion inhibitors using a bivalent drug design approach

We reported the design of fusion inhibitors with improved activity using a multivalent inhibitor design strategy. First, we chose C29 as the template sequence, which is a 29-mer peptide derived from HIV-1 gp41 CHR domain and has anti-HIV activity of IC₅₀ 118 nM in a cell–cell fusion assay. We optimized the crosslink sites and linkers of the template peptide. We found that N-terminal crosslink caused activity improvement based on the multivalent co-operative effect. Especially, the IC₅₀ of peptide (CAcaC29)₂ was improved from 49.02 (monomeric form) to 5.71 nM. Compared with long peptides, short peptides may be more suitable to analyze the co-operative effect. So we selected a shorter peptide C22 to synthesize the bivalent inhibitors. Due its weak helicity, no co-operative effect appeared. Therefore, we chose SC22EK, which were introduced salt bridges to consolidate the helicity based on the natural sequence C22. The cross-linked (CAcaSC22EK)₂ was four times more potent than the monomer SC22EK in anti-HIV activity, with an IC₅₀ value of 4.92 nM close to the high active peptide fusion inhibitor C34. The strategy used in this study may be used to design new fusion inhibitors to interfere similar processes.