RhoGAPs Attenuate Cell Proliferation by Direct Interaction with p53 Tetramerization Domain

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SDS Interferes with SaeS Signaling of Staphylococcus aureus Independently of SaePQ

The Staphylococcus aureus regulatory saePQRS system controls the expression of numerous virulence factors, including extracellular adherence protein (Eap), which amongst others facilitates invasion of host cells. The saePQRS operon codes for 4 proteins: the histidine kinase SaeS, the response regulator SaeR, the lipoprotein SaeP and the transmembrane protein SaeQ. S. aureus strain Newman has a single amino acid substitution in the transmembrane domain of SaeS (L18P) which results in constitutive kinase activity. SDS was shown to be one of the signals interfering with SaeS activity leading to inhibition of the sae target gene eap in strains with SaeS^L but causing activation in strains containing SaeS^P. Here, we analyzed the possible involvement of the SaeP protein and saePQ region in SDS-mediated sae/eap expression. We found that SaePQ is not needed for SDS-mediated SaeS signaling. Furthermore, we could show that SaeS activity is closely linked to the expression of Eap and the capacity to invade host cells in a number of clinical isolates. This suggests that SaeS activity might be directly modulated by structurally non-complex environmental signals, as SDS, which possibly altering its kinase/phosphatase activity.     

Optimization of Substituted 6-Salicyl-4-Anilinoquinazoline Derivatives as Dual EGFR/HER2 Tyrosine Kinase Inhibitors

4-Anilinoquinazolines as an important class of protein kinase inhibitor are widely investigated for epidermal growth factor receptor (EGFR) tyrosine kinase or epidermal growth factor receptor 2 (HER2) inhibition. A series of novel 6-salicyl-4-anilinoquinazoline derivatives 9–27 were prepared and evaluated for their EGFR/HER2 tyrosine kinase inhibitory activity as well as their antiproliferative properties on three variant cancer cell lines (A431, MCF-7, and A549). The bioassay results showed most of the designed compounds exhibited moderate to potent in vitro inhibitory activity in the enzymatic and cellular assays, of which compound 21 revealed the most potent dual EGFR/HER2 inhibitory activity, with IC₅₀ values of 0.12 µM and 0.096 µM, respectively, comparable to the control compounds Erlotinib and Lapatinib. Furthermore, the kinase selectivity profile of 21 was accessed and demonstrated its good selectivity over the majority of the close kinase targets. Docking simulation was performed to position compound 21 into the EGFR/HER2 active site to determine the probable binding pose. These new findings along with molecular docking observations could provide an important basis for further development of compound 21 as a potent EGFR/HER2 dual kinase inhibitor.     

QC-Chain: Fast and Holistic Quality Control Method for Next-Generation Sequencing Data

Next-generation sequencing (NGS) technologies have been widely used in life sciences. However, several kinds of sequencing artifacts, including low-quality reads and contaminating reads, were found to be quite common in raw sequencing data, which compromise downstream analysis. Therefore, quality control (QC) is essential for raw NGS data. However, although a few NGS data quality control tools are publicly available, there are two limitations: First, the processing speed could not cope with the rapid increase of large data volume. Second, with respect to removing the contaminating reads, none of them could identify contaminating sources de novo, and they rely heavily on prior information of the contaminating species, which is usually not available in advance. Here we report QC-Chain, a fast, accurate and holistic NGS data quality-control method. The tool synergeticly comprised of user-friendly tools for (1) quality assessment and trimming of raw reads using Parallel-QC, a fast read processing tool; (2) identification, quantification and filtration of unknown contamination to get high-quality clean reads. It was optimized based on parallel computation, so the processing speed is significantly higher than other QC methods. Experiments on simulated and real NGS data have shown that reads with low sequencing quality could be identified and filtered. Possible contaminating sources could be identified and quantified de novo, accurately and quickly. Comparison between raw reads and processed reads also showed that subsequent analyses (genome assembly, gene prediction, gene annotation, etc.) results based on processed reads improved significantly in completeness and accuracy. As regard to processing speed, QC-Chain achieves 7–8 time speed-up based on parallel computation as compared to traditional methods. Therefore, QC-Chain is a fast and useful quality control tool for read quality process and de novo contamination filtration of NGS reads, which could significantly facilitate downstream analysis. QC-Chain is publicly available at: http://www.computationalbioenergy.org/qc-chain.html.     

Increased Expression of IL-22 Is Associated with Disease Activity in Behcet’s Disease

Objective

Interleukin (IL)-22 has been reported to be involved in the development of autoimmune diseases. This study aimed to analyze the expression and potential role of IL-22 in the pathogenesis of Behcet’s disease (BD).

Methods

The levels of IL-22 in patient sera or supernatants of cultured peripheral blood mononuclear cells (PBMCs) and CD4⁺T cells were detected by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was used to evaluate the frequency of IL-22–producing CD4⁺ T cells. IL-22 mRNA from erythema nodosum skin lesions was examined using real time quantitative RT-PCR.

Results

BD patients with active uveitis showed a significantly higher expression of IL-22 in the supernatants of stimulated PBMCs and CD4⁺T cells compared with BD patients without active uveitis and normal controls. An increased frequency of IL-22-producing CD4⁺T cells was also found in BD patients with active uveitis. IL-22 mRNA expression was elevated in erythema nodosum skin lesions. In BD patients, a high IL-22 level in the supernatant of stimulated PBMCs correlated with the presence of retinal vasculitis and erythema nodosum.

Conclusions

IL-22 was associated with disease activity in BD and correlated with the presence of small vessel inflammation, suggesting that it may be involved in its pathogenesis.     

Mapping and Congenic Dissection of Genetic Loci Contributing to Hyperglycemia and Dyslipidemia in Mice

Background

Patients with dyslipidemia have an increased risk of developing type 2 diabetes, and diabetic patients often have dyslipidemia. Potential genetic connections of fasting plasma glucose with plasma lipid profile were evaluated using hyperlipidemic mice.

Methods

225 male F₂ mice were generated from BALB/cJ (BALB) and SM/J(SM) Apoe-deficient (Apoe^−/−) mice and fed a Western diet for 5 weeks. Fasting plasma glucose and lipid levels of F₂ mice were measured before and after 5 weeks of Western diet and quantitative trait locus (QTL) analysis was performed using data collected from these two time points. 144 SNP(single nucleotide polymorphism) markers across the entire genome were typed.

Results

One major QTL (logarithm of odds ratio (LOD): 6.46) peaked at 12.7 cM on chromosome 9,Bglu16, and 3 suggestive QTLs on chromosomes 15, 18 and X were identified for fasting glucose, and over 10 loci identified for lipid traits. Bglu16 was adjacent to a major QTL, Hdlq17, for high-density lipoprotein (HDL) cholesterol (LOD: 6.31, peak: 19.1 cM). A congenic strain with a donor chromosomal region harboring Bglu16 and Hdlq17 on the Apoe^−/− background showed elevations in plasma glucose and HDL levels. Fasting glucose levels were significantly correlated with non-HDL cholesterol and triglyceride levels, especially on the Western diet, but only marginally correlated with HDL levels in F₂ mice.

Conclusions

We have demonstrated a correlative relationship between fasting glucose and plasma lipids in a segregating F₂ population under hyperlipidemic conditions, and this correlation is partially due to genetic linkage between the two disorders.     

Upregulation of KLHDC4 Predicts a Poor Prognosis in Human Nasopharyngeal Carcinoma

Kelch proteins are implicated in the pathogenesis of many human diseases, including cancer. Nasopharyngeal carcinoma (NPC) is a rare malignancy in most countries, but prevalent in southern China and certain areas of Southeast Asia. In this study, we identified Kelch Domain Containing 4 (KLHDC4), an orphan member of the kelch repeat superfamily, as a prognosis marker for NPC. We examined the expression of KLHDC4 in 168 NPC cases by immunohistochemical staining and found a substantially higher level of KLHDC4 in NPC biopsies compared to adjacent normal nasopharyngeal mucosa. KLHDC4 expression was significantly related to the T classification (P <0.05), N classification (P <0.05) and total staging (P <0.01) in NPC, and patients with higher KLHDC4 expression had poorer overall (P <0.01) and metastasis-free survival (P <0.05) rates. Knockout (KO) of KLHDC4 via CRISPR/Cas9-mediated gene editing in NPC cell line dramatically inhibited cell proliferation, colony formation in soft agar and tumor formation in nude mice. In addition, cell migration and invasion were also impaired by KLHDC4 depletion as revealed by wound healing and Transwell assay. Mechanically, loss of KLHDC4 markedly induced spontaneous apoptosis in NPC cells, as evidenced by increased levels of cleaved caspase-3 and cleaved PARP. Consistently, KLHDC4 knockout cell-derived xenografts also showed elevated cleaved caspase-3 and PARP but reduced Ki-67 staining. In conclusion, our results suggest that KLHDC4 promotes NPC oncogenesis by suppressing cellular apoptosis. Thus, KLHDC4 may serve as a prognosis biomarker and a potential therapeutic target for NPC.