Inter-Alpha-Trypsin Inhibitor Heavy Chain 4 Plays an Important Role in the Development and Reproduction of Nilaparvata lugens.

The brown planthopper, Nilaparvata lugens, is a difficult-to-control insect pest affecting rice yields in Asia. As a structural component of the inter-alpha-trypsin inhibitor (ITI), the inter-alpha-trypsin inhibitor heavy chain (ITIH) has been reported to be involved in various inflammatory or malignant disorders, ovarian development, and ovulation. To reveal the function of ITIH4 in N. lugens, the gene encoding N. lugens ITIH4 (NlITIH4) was cloned and characterized. NlITIH4 contains a signal peptide, a vault protein inter-alpha-trypsin domain, and a von Willebrand factor type A domain. qPCR analysis showed that NlITIH4 was expressed at all developmental stages and in all tissues (fat body, ovary, and gut), with the highest expression in the fat body. Double stranded NlITIH4 (dsNlITIH4) injection clearly led to an RNAi-mediated inhibition of the expression of NlITIH4 and resulted in reduced survival, delayed ovarian development, and reduced egg production and egg hatching. These results indicate that NlITIH4 plays an important role in the development and reproduction of N. lugens.

The essential roles of Mps1 in spermatogenesis and fertility in mice.

Monopolar spindle 1 (MPS1), which plays a critical role in somatic mitosis, has also been revealed to be essential for meiosis I in oocytes. Spermatogenesis is an important process involving successive mitosis and meiosis, but the function of MPS1 in spermatogenesis remains unclear. Here, we generated Mps1 conditional knockout mice and found that Ddx4-cre-driven loss of Mps1 in male mice resulted in depletion of undifferentiated spermatogonial cells and subsequently of differentiated spermatogonia and spermatocytes. In addition, Stra8-cre-driven ablation of Mps1 in male mice led to germ cell loss and fertility reduction. Spermatocytes lacking Mps1 have blocked at the zygotene-to-pachytene transition in the prophase of meiosis I, which may be due to decreased H2B ubiquitination level mediated by MDM2. And the expression of many meiotic genes was decreased, while that of apoptotic genes was increased. Moreover, we also detected increased apoptosis in spermatocytes with Mps1 knockout, which may have been the reason why germ cells were lost. Taken together, our findings indicate that MPS1 is required for mitosis of gonocytes and spermatogonia, differentiation of undifferentiated spermatogonia, and progression of meiosis I in spermatocytes.

Epigenetic regulation of the Warburg effect by H2B monoubiquitination.

Cancer cells reprogram their energy metabolic system from the mitochondrial oxidative phosphorylation (OXPHOS) pathway to a glucose-dependent aerobic glycolysis pathway. This metabolic reprogramming phenomenon is known as the Warburg effect, a significant hallmark of cancer. However, the detailed mechanisms underlying this event or triggering this reprogramming remain largely unclear. Here, we found that histone H2B monoubiquitination (H2Bub1) negatively regulates the Warburg effect and tumorigenesis in human lung cancer cells (H1299 and A549 cell lines) likely through controlling the expression of multiple mitochondrial respiratory genes, which are essential for OXPHOS. Moreover, our work also suggested that pyruvate kinase M2 (PKM2), the rate-limiting enzyme of glycolysis, can directly interact with H2B in vivo and in vitro and negatively regulate the level of H2Bub1. The inhibition of cell proliferation and nude mice xenograft of human lung cancer cells induced by PKM2 knockdown can be partially rescued through lowering H2Bub1 levels, which indicates that the oncogenic function of PKM2 is achieved, at least partially, through the control of H2Bub1. Furthermore, PKM2 and H2Bub1 levels are negatively correlated in cancer specimens. Therefore, these findings not only provide a novel mechanism triggering the Warburg effect that is mediated through an epigenetic pathway (H2Bub1) but also reveal a novel metabolic regulator (PKM2) for the epigenetic mark H2Bub1. Thus, the PKM2-H2Bub1 axis may become a promising cancer therapeutic target.

Joint statistics matching for camera model identification of recompressed images.

Source camera identification has been well studied in laboratory environment where the training and test samples are all original images without recompression. However, image compression is quite common in the real world, when the training and test images are double JPEG compressed with different quantization tables, the identification accuracy of existing methods decreases dramati- cally. To address this challenge, we propose a novel iterative algorithm namely joint first and second order statistics matching (JSM) to learn a feature projection that projects the training and test fea- tures into a low dimensional subspace to reduce the shift caused by image recompression. Inspired by transfer learning, JSM aims to learn a new feature representation from original feature space by simultaneously matching the first and second order statistics between training and test features in a principled dimensionality reduction procedure. After the feature projection, the divergence between training and test features caused by recompression is reduced while the discriminative properties are preserved. Extensive experiments on public Dresden Image Database verify that JSM significantly outperforms several state-of-the-art methods on camera model identification of recompressed images.

JPEG compression history detection based on detail deviation.

The authenticity of the image is crucial to many cases. The efficient detection of the JPEG compression history of bitmap image could reveal the possibility of tampering on the image. In this paper, we propose a lightweight but reliable JPEG compression detection method based on image information loss. An efficient feature of the decreasing percentage of zero coefficient is proposed to detect the JPEG compression history of an image, due to the increasing JPEG compression quality factor. In our method, estimated original images are first created. Then the given image and its estimated counterpart are compressed to get the JPEG coefficient. After that, the image information loss will be calculated. Through the analysis, the goal of the compression history detection can be achieved. Extensive experimental results have demonstrated that the proposed method outperforms the existing methods.

Histone acetyltransferase CBP-related H3K23 acetylation contributes to courtship learning in Drosophila.

BACKGROUND: Histone modifications are critical in regulating neuronal processes. However, the impacts of individual histone modifications on learning and memory are elusive. Here, we investigated the contributions of histone H3 lysine modifications to learning and memory in Drosophila by using histone lysine-to-alanine mutants. RESULTS: Behavioural analysis indicated that compared to the H3WT group, mutants overexpressing H3K23A displayed impaired courtship learning. Chromatin immunoprecipitation analysis of H3K23A mutants showed that H3K23 acetylation (H3K23ac) levels were decreased on learning-related genes. Knockdown of CREB-binding protein (CBP) decreased H3K23ac levels, attenuated the expression of learning-related genes, led to a courtship learning defect and altered development of the mushroom bodies. A decline in courtship learning ability was observed in both larvae and adult treatments with ICG-001. Furthermore, treatment of Drosophila overexpressing mutated H3K23A with a CBP inhibitor did not aggravate the learning defect. CONCLUSIONS: H3K23ac, catalysed by the acetyltransferases dCBP, contributes to Drosophila learning, likely by controlling the expression of specific genes. This is a novel epigenetic regulatory mechanism underlying neuronal behaviours.

Interactome Analysis Reveals a Novel Role for RAD6 in the Regulation of Proteasome Activity and Localization in Response to DNA Damage.

RAD6, an E2 ubiquitin-conjugating enzyme, is a key node for determining different DNA damage repair pathways, controlling both the error-prone and the error-free DNA damage repair pathways through differential regulation of the ubiquitination of the proliferating cell nuclear antigen (PCNA) protein. However, whether other pathways are involved in the RAD6-mediated regulation of DNA damage repair is still unclear. To deeply understand the molecular mechanisms of RAD6 in DNA damage repair, we performed a proteomic analysis and identified the changes of the protein-protein interaction (PPI) networks of RAD6 before and after X-ray irradiation. Furthermore, our study indicated that a proteasome-related event is likely involved in the DNA damage repair process. Moreover, we found that RAD6 promotes proteasome activity and nuclear translocation by enhancing the degradation of PSMF1 and the lamin B receptor (LBR). Therefore, we provide a novel pathway that is employed by RAD6 in response to DNA damage.

[Preparation of enteric nanoparticles of Schisandra total lignanoids and preliminary study on its pharmacokinetics].

To study the preparation method of Schisandra total lignanoids enteric (SLE) nanoparticles and evaluate its pharmacokinetics in rats, SLE nanoparticles were prepared by modified emulsion solvent diffusion method. The properties of SLE nanoparticles were evaluated of morphology, mean diameter and entrapment efficiency. An HPLC method was employed to determine the concentration of deoxyschisandrin (QS) and schisantherin A (SA) in plasma, which were used as an index of Schisandra total lignanoids, and the bioavailability of the nanoparticles was compared with the reference group by oral administration using SD rats. The nanoparticles observed by transmission electronmicroscopy were round, and the mean particle sizes of SLE were (36.7 +/- 4.4) nm. Entrapment efficiency of QS and SA were (97.5 +/- 0.7)% and (91.3 +/- 0.8)%, respectively. Its pharmacokinetic process calculated with 3p97 software was fitted to a one-compartment model. The pharmacokinetic parameters showed sustained-release property. Compared with reference formulation, the AUCs of SLE nanoparticles were 2.3 and 5.8 times separately. These results suggested that the incorporation into Eudragit S100 of Schisandra total lignanoids can improve the bioavailability.