Gab2 facilitates epithelial-to-mesenchymal transition via the MEK/ERK/MMP signaling in colorectal cancer

Clinicopathologic factors and Gab2 expression in 35 CRC patients. (DOCX 22 kb

The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∼120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella

TLR7 modulates extramedullary splenic erythropoiesis in P. yoelii NSM-infected mice through the regulation of iron metabolism of macrophages with IFN-γ

Splenomegaly is a prominent clinical manifestation of malaria and the causes remain incompletely clear. Anemia is induced in malaria and extramedullary splenic erythropoiesis is compensation for the loss of erythrocytes. However, the regulation of extramedullary splenic erythropoiesis in malaria is unknown. An inflammatory response could facilitate extramedullary splenic erythropoiesis in the settings of infection and inflammation. Here, when mice were infected with rodent parasites, Plasmodium yoelii NSM, TLR7 expression in splenocytes was increased. To explore the roles of TLR7 in splenic erythropoiesis, we infected wild-type and TLR7-/- C57BL/6 mice with P. yoelii NSM and found that the development of splenic erythroid progenitor cells was impeded in TLR7-/- mice. Contrarily, the treatment of the TLR7 agonist, R848, promoted extramedullary splenic erythropoiesis in wild-type infected mice, which highlights the implication of TLR7 on splenic erythropoiesis. Then, we found that TLR7 promoted the production of IFN-γ that could enhance phagocytosis of infected erythrocytes by RAW264.7. After phagocytosis of infected erythrocytes, the iron metabolism of RAW264.7 was upregulated, evidenced by higher iron content and expression of Hmox1 and Slc40a1. Additionally, the neutralization of IFN-γ impeded the extramedullary splenic erythropoiesis modestly and reduced the iron accumulation in the spleen of infected mice. In conclusion, TLR7 promoted extramedullary splenic erythropoiesis in P. yoelii NSM-infected mice. TLR7 enhanced the production of IFN-γ, and IFN-γ promoted phagocytosis of infected erythrocytes and the iron metabolism of macrophages in vitro, which may be related to the regulation of extramedullary splenic erythropoiesis by TLR7

The <i>Sinocyclocheilus</i> cavefish genome provides insights into cave adaptation

BACKGROUND: An emerging cavefish model, the cyprinid genus Sinocyclocheilus, is endemic to the massive southwestern karst area adjacent to the Qinghai-Tibetan Plateau of China. In order to understand whether orogeny influenced the evolution of these species, and how genomes change under isolation, especially in subterranean habitats, we performed whole-genome sequencing and comparative analyses of three species in this genus, S. grahami, S. rhinocerous and S. anshuiensis. These species are surface-dwelling, semi-cave-dwelling and cave-restricted, respectively. RESULTS: The assembled genome sizes of S. grahami, S. rhinocerous and S. anshuiensis are 1.75 Gb, 1.73 Gb and 1.68 Gb, respectively. Divergence time and population history analyses of these species reveal that their speciation and population dynamics are correlated with the different stages of uplifting of the Qinghai-Tibetan Plateau. We carried out comparative analyses of these genomes and found that many genetic changes, such as gene loss (e.g. opsin genes), pseudogenes (e.g. crystallin genes), mutations (e.g. melanogenesis-related genes), deletions (e.g. scale-related genes) and down-regulation (e.g. circadian rhythm pathway genes), are possibly associated with the regressive features (such as eye degeneration, albinism, rudimentary scales and lack of circadian rhythms), and that some gene expansion (e.g. taste-related transcription factor gene) may point to the constructive features (such as enhanced taste buds) which evolved in these cave fishes. CONCLUSION: As the first report on cavefish genomes among distinct species in Sinocyclocheilus, our work provides not only insights into genetic mechanisms of cave adaptation, but also represents a fundamental resource for a better understanding of cavefish biology. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12915-015-0223-4) contains supplementary material, which is available to authorized users

Regulation of flagellar biogenesis by a calcium dependent protein kinase in Chlamydomonas reinhardtii.

Chlamydomonas reinhardtii, a bi-flagellated green alga, is a model organism for studies of flagella or cilia related activities including cilia-based signaling, flagellar motility and flagellar biogenesis. Calcium has been shown to be a key regulator of these cellular processes whereas the signaling pathways linking calcium to these cellular functions are less understood. Calcium-dependent protein kinases (CDPKs), which are present in plants but not in animals, are also present in ciliated microorganisms which led us to examine their possible functions and mechanisms in flagellar related activities. By in silico analysis of Chlamydomonas genome we have identified 14 CDPKs and studied one of the flagellar localized CDPKs--CrCDPK3. CrCDPK3 was a protein of 485 amino acids and predicted to have a protein kinase domain at the N-terminus and four EF-hand motifs at the C-terminus. In flagella, CrCDPK3 was exclusively localized in the membrane matrix fraction and formed an unknown 20 S protein complex. Knockdown of CrCDPK3 expression by using artificial microRNA did not affect flagellar motility as well as flagellar adhesion and mating. Though flagellar shortening induced by treatment with sucrose or sodium pyrophosphate was not affected in RNAi strains, CrCDPK3 increased in the flagella, and pre-formed protein complex was disrupted. During flagellar regeneration, CrCDPK3 also increased in the flagella. When extracellular calcium was lowered to certain range by the addition of EGTA after deflagellation, flagellar regeneration was severely affected in RNAi cells compared with wild type cells. In addition, during flagellar elongation induced by LiCl, RNAi cells exhibited early onset of bulbed flagella. This work expands new functions of CDPKs in flagellar activities by showing involvement of CrCDPK3 in flagellar biogenesis in Chlamydomonas

CrCDPK3 is present in the flagella of <i>C. reinhardtii</i>.

<p>(A) Schematic diagram of CrCDPK3 gene showing exons (grey) and introns (white). (B) Immunoblot analysis of <i>Chlamydomonas</i> cell lysates, bacterial expressed GST-CrCDPK3 and GST shows that anti-CrCDPK3 antibody is specific. Molecular weights are given in kilo-daltons. (C) CrCDPK3 is present in the cell body and flagella evidenced by immuoblotting with anti-CrCDPK3 antibody. 1 x indicates that approximately two flagella were loaded per cell body. 50 x indicates equal flagellar and cell body protein. (D) Isolated flagella (F), membrane/matrix (M and M) and axonemal (Ax) fractions were analyzed by immunoblotting with antibodies as indicated. (E) Immunostaining of cells expressing CrCDPK3-HA (a) or not (b) with antibodies against 3xHA tag and α-tubulin. Bars, 5 µm.</p

Requirement of calcium and CrCDPK3 for flagellar regeneration.

<p>(A) After deflagellation by mechanical shearing, 2.3 mM EGTA (final concentration) was added to the cell samples or not. At 120 min after deflagellation, CaCl₂ was added to EGTA treated samples to reach 0.36 mM calcium present in normal medium. Samples were fixed at different times for flagellar length measurement. (B) Titration of [Ca²⁺]_e to determine calcium-dependent flagellar regeneration. After deflagellation, flagellar regeneration was allowed to proceed at different [Ca²⁺]_es. (C) Flagellar regeneration of CrCDPK3 RNAi strains at lower [Ca²⁺]_es. (D) Flagellar regeneration after transferring cells grown on agar plates into liquid medium. (E) Cell samples before (time 0) and at different times during flagellar regeneration after deflagellation were subjected to immunoblot analysis with anti-CrCDPK3 and anti-JPK1 antibodies. (F) Immunoblot analysis of CrCDPK3 in flagella from steady state cells and cells undergoing flagellar regeneration for 20 min. Equal flagelar proteins were loaded. IFT139 was used as positive control, which was shown to increase in regenerating flagella, and FMG1 used as loading control.</p

Characterization of CrCDPK3 during flagellar shortening.

<p>(A) Cells were treated with 20 mM NaPPi to induce flagellar shortening followed by cell fixation and flagellar length measurement. No apparent difference in shortening was observed between two RNAi and wild type strains. (B) Flagellar increase of CrCDPK3 upon induction of flagellar shortening. Cells were treated with 20 mM NaPPi or 0.2 M sucrose followed by flagellar isolation and immunoblotting with antibodies indicated. (C) Formation of flagellar CrCDPK3 complex and its disruption upon induction of flagellar shortening. Flagella were isolated from steady state cells and cells treated with 20 mM NaPPi for 10 min followed by extraction of membrane/matrix fractions, which were analyzed by a 10-25% sucrose gradient and immunoblotting. Note that CrCDPK3 formed a complex around 20 S in steady state flagella and was disrupted upon inducing flagellar shortening.</p