Basement Membrane beneath Serous Mesothelial Cells Contains α1(IV), α2(IV), α5(IV), and α6(IV) Chains of Type IV Collagen Demonstrated by Chain-specific Monoclonal Antibodies

Serous membrane (SM) covers inner surface of abdominal, thoracic and pericardial cavities, aswell as outer surface of organs inside the cavities. It consists of surface mesothelial cells andloose connective tissue. Between them, a thim layer of basement membrane (BM) is located. Type IVcollagen is major constituent of BM, and consists of 6 different a(IV) chains, a1(IV) through a6(IV).Chain-specific functions are assumed by a chain-specific manner of localization. The a(IV) chaincomposition of skin, covering outer surface of the body, is demonstrated to have a1(IV), a2(IV), a5(IV),and a6(IV) chains, whereas that of SM, covering inner surface of the body, is yet to be analyzed. Abdominal wall, small intestine, thoracic wall, lung, pericardium and epicardium of humanmaterials were used in this study. Chain-specific monoclonal antibodies (mAbs) used were H11(for a1), H22 (for a2), H31 (fo a3), H43 (for a4), H53 (for a5) and H63 (for a6). Fresh frozen sectionswere stained with indirect immunofluorescence staining using the mAbs. Four out of six a(IV) chains, a1, a2, a5 and a6, were demonstrated in BM beneath themesothelial cells of all types of SMs, whereas only capillary BM consisted of a1 and a2. Besides,epicardial SM expressed a3 and a4 moderately as extra components. The a(IV) chain composition was same as those of epidermal skin BM. Therefore, these a(IV)chains are designated to be essential for BM covering inside and outside of the body

ダイガク ニオケル イッパン キョウイク カモク セイブツガク ワ ドウ アル ベキカ

Since the beginning of 20th century,universities and colleges in Japan like occidentalcounterparts have traditionally been requiring the so-called general education courses (liberalarts) for undergraduate studedents. The reason is simple to enlighten the professional-to-bestudents with general intellectual capacities. In recent years, however, general education hassomehow been underestimated at if it is minor and less significant. Biology as well as physics andchemistry in the field of natural science has been recognized in this way, thus the students showlittle interests, and even teachers lack eagerness and corage toward teaching the courses. Inthis paper, the authors, with different backgrounds and expertises within biology have intimatelydiscussed and analyzed the recent situation and reached criticism with our mutualrecommendations for biological science in liberal arts at university level

スゲゾク シバスゲセツ ニオケル ヨウリョクタイ DNA オ モチイタ ブンシ ケイトウガクテキ ケンキュウ

カヤツリグサ科スゲ属植物は, 種類が非常に多く, しかも形態がよく似ており分類が困難なグループである。本研究では, スゲ属のRFLPs分析による系統分類を目的として葉緑体DNAの単離を試みた。しかし, 葉の組織がケイ素の集積で硬く繊維質が多いため純度の高い葉緑体が得られずDNAの収量が悪かった。そこで, スゲ属シバスゲ節の種内異数体を含む4種の全DNAをCTAB法によって単離し, イネの葉緑体DNAをプローブとしてサザンハイブリダイゼーションを行った。その結果, 4種間および種内異数体間で異なる断片パターンが認められ, このRELPs分析が本属の系統の解析に有効であることが明らかになった。The species Carex are difficult to distinguish because the morphological features are very similar. In order to clarify the phylogenetic relationships among the species of this genus, restriction fragment analysis of cpDNA was applied to four species of section Praecoces. Total DNA was isolated from fresh leaves by the CTAB procedure and digested with four restriction enzymes. The probes for Southern hybridization were prepared from the clone bank of Oryza sativa cpDNA. Different restriction sites were recognized among four species and intraspecific aneuploids of Carex conica. This result shows the restriction fragment analysis of cpDNA is an effectual method of phylogenetic analysis in the genus Carex

Integrating an integrin: a direct route to actin

AbstractIntegrins were so named for their ability to link the extracellular and intracellular skeletons. Now almost 20 years into integrin research, numerous questions remain as to how this interaction is accomplished and how it is modified to achieve a desired phenotype. As the cell adhesion and actin assembly fields are merging in combined approaches, novel actin assembly mechanisms are being uncovered. Some of the earliest identified cytoplasmic linker molecules, believed to mediate integrin-actin binding, are once again the subject of scrutiny as potential dynamic mediators of cell anchorage. It seems plausible that each unique cellular morphology occurs as the result of activation of distinct actin assembly systems that are either stabilized by unique bundling and linker proteins or modified for progression to a new phenotype. While this research initiative is likely to continue rapidly in a forward fashion, it remains to be clarified how integrins assemble the most stable and basic cytoskeletal phenotype, the adherent cell with prominent stress fibers. Recent investigations point towards a shift in the current model of anchoring at the cell periphery by providing both mechanisms and evidence for de novo actin assembly orchestrated by the adhesion site. Lacking a complete pathway from integrin ligation to an integrated extracellular–intracellular skeleton in any single system, this review proposes a simple model of integrin-mediated stress fiber integration by drawing from work in multiple systems

Conditional Genetic Elimination of Hepatocyte Growth Factor in Mice Compromises Liver Regeneration after Partial Hepatectomy

Hepatocyte growth factor (HGF) has been shown to be indispensable for liver regeneration because it serves as a main mitogenic stimulus driving hepatocytes toward proliferation. We hypothesized that ablating HGF in adult mice would have a negative effect on the ability of hepatocytes to regenerate. Deletion of the HGF gene was achieved by inducing systemic recombination in mice lacking exon 5 of HGF and carrying the Mx1-cre or Cre-ERT transgene. Analysis of liver genomic DNA from animals 10 days after treatment showed that a majority (70-80%) of alleles underwent cre-induced genetic recombination. Intriguingly, however, analysis by RT-PCR showed the continued presence of both unrecombined and recombined forms of HGF mRNA after treatment. Separation of liver cell populations into hepatocytes and non-parenchymal cells showed equal recombination of genomic HGF in both cell types. The presence of the unrecombined form of HGF mRNA persisted in the liver in significant amounts even after partial hepatectomy (PH), which correlated with insignificant changes in HGF protein and hepatocyte proliferation. The amount of HGF produced by stellate cells in culture was indirectly proportional to the concentration of HGF, suggesting that a decrease in HGF may induce de novo synthesis of HGF from cells with residual unrecombined alleles. Carbon tetrachloride (CCl4)-induced regeneration resulted in a substantial decrease in preexisting HGF mRNA and protein, and subsequent PH led to a delayed regenerative response. Thus, HGF mRNA persists in the liver even after genetic recombination affecting most cells; however, PH subsequent to CCl4 treatment is associated with a decrease in both HGF mRNA and protein and results in compromised liver regeneration, validating an important role of this mitogen in hepatic growth. © 2013 Nejak-Bowen et al

Mg-chelatase H subunit affects ABA signaling in stomatal guard cells, but is not an ABA receptor in Arabidopsis thaliana

Mg-chelatase H subunit (CHLH) is a multifunctional protein involved in chlorophyll synthesis, plastid-to-nucleus retrograde signaling, and ABA perception. However, whether CHLH acts as an actual ABA receptor remains controversial. Here we present evidence that CHLH affects ABA signaling in stomatal guard cells but is not itself an ABA receptor. We screened ethyl methanesulfonate-treated Arabidopsis thaliana plants with a focus on stomatal aperture-dependent water loss in detached leaves and isolated a rapid transpiration in detached leaves 1 (rtl1) mutant that we identified as a novel missense mutant of CHLH. The rtl1 and CHLH RNAi plants showed phenotypes in which stomatal movements were insensitive to ABA, while the rtl1 phenotype showed normal sensitivity to ABA with respect to seed germination and root growth. ABA-binding analyses using 3H-labeled ABA revealed that recombinant CHLH did not bind ABA, but recombinant pyrabactin resistance 1, a reliable ABA receptor used as a control, showed specific binding. Moreover, we found that the rtl1 mutant showed ABA-induced stomatal closure when a high concentration of extracellular Ca2+ was present and that a knockout mutant of Mg-chelatase I subunit (chli1) showed the same ABA-insensitive phenotype as rtl1. These results suggest that the Mg-chelatase complex as a whole affects the ABA-signaling pathway for stomatal movements

Extracellular ATP acts on P2Y2 purinergic receptors to facilitate HIV-1 infection

Contact with HIV-1 envelope protein elicits release of ATP through pannexin-1 channels on target cells; by activating purinergic receptors and Pyk2 kinase in target cells, this extracellular ATP boosts HIV-1 infectivity

Macrophage signaling in HIV-1 infection

The human immunodeficiency virus-1 (HIV-1) is a member of the lentivirus genus. The virus does not rely exclusively on the host cell machinery, but also on viral proteins that act as molecular switches during the viral life cycle which play significant functions in viral pathogenesis, notably by modulating cell signaling. The role of HIV-1 proteins (Nef, Tat, Vpr, and gp120) in modulating macrophage signaling has been recently unveiled. Accessory, regulatory, and structural HIV-1 proteins interact with signaling pathways in infected macrophages. In addition, exogenous Nef, Tat, Vpr, and gp120 proteins have been detected in the serum of HIV-1 infected patients. Possibly, these proteins are released by infected/apoptotic cells. Exogenous accessory regulatory HIV-1 proteins are able to enter macrophages and modulate cellular machineries including those that affect viral transcription. Furthermore HIV-1 proteins, e.g., gp120, may exert their effects by interacting with cell surface membrane receptors, especially chemokine co-receptors. By activating the signaling pathways such as NF-kappaB, MAP kinase (MAPK) and JAK/STAT, HIV-1 proteins promote viral replication by stimulating transcription from the long terminal repeat (LTR) in infected macrophages; they are also involved in macrophage-mediated bystander T cell apoptosis. The role of HIV-1 proteins in the modulation of macrophage signaling will be discussed in regard to the formation of viral reservoirs and macrophage-mediated T cell apoptosis during HIV-1 infection