31 research outputs found
A case of chronic actinic dermatitis that responded completely to treatment with oral colostrum‐macrophage‐activating factor (colostrum‐MAF)
Neural-tube specific paralogous genes and their upstream regulatory sequences
Ascidians are primitive chordates, and their critical evolutionary position expected to offer an excellent experimental system to understand the origin and the evolution of vertebrates (Satoh, 1994). Especially, neural tube is one of the characteristic features of chordates. In this study, we focused on the mechanism of the neural tube formation, and described the detailed expression profiles of two neural tube specific genes, CiNutl and CiNut2. Although the amount of CiNut2 expression is about 1/1000 compared to that of CiNutl, both two genes are expressed in the entire neural plate and neural tube during the course of the development. Both two genes are situated in an adjacent position of the chromosome in the same direction. Comparative analysis of the upstream regulatory sequence of two genes revealed the conserved sequences, which suggested having a role for the neural tube specific expression
様々な物質とペプチドの複合体におけるナノ・バイオへの応用展開の検討
研究目的:近年、機能性中分子として注目されているペプチド (小タンパク質 を、さらに高機能化、多機能化させることを指向して、生体分子、無機化合物、有機小分子、高分子などと複合させた新規機能性複合体の創製を目的とする。また、これら複合体を用いたナノ分野やバイオ分野への応用展開の検討も行う 。研究概要:これまで分子単体では達成できなかったような高機能・多機能性の材料開発を目指し、無機化合物、有機小分子、高分子とペプチドを複合させた新規機能性複合体を創製する。その創製に際しては、近年、機能性中分子として注目されているペプチドを基に、ある機能を有するペプチドに、糖、核酸、酵素などの生体分子、有機合成小分子、合成高分子、無機化合物などをそれらと結合するペプチドリガンドを介して あるいは共有結合などで 複合させることで、従来以上 に 高機能化、多機能化 させた分子・複合体の創製 をねらう。さらに、本研究で作製できた複合体を用 いて、多段階触媒能を有する材料や、エレクトロニクス材料、特定疾病分子などを高度に検出できる素子、治療に役立つ薬剤などの開発につなげ、ナノ分野、バイオ分野への工学的な応用展開を検討する
Microtubule array observed in the posterior-vegetal cortex during cytoplasmic and cortical reorganization of the ascidian egg
Body axis formation during embryogenesis results from asymmetric localization of maternal factors in the egg. Shortly before the first cleavage in ascidian eggs, cell polarity along the anteroposterior (A-P) axis is established and the cytoplasmic domain (myoplasm) relocates from the vegetal to the posterior region in a microtubule-dependent manner. Through immunostaining, tubulin accumulation during this reorganization is observable on the myoplasm cortex. However, more detailed morphological features of microtubules remain relatively unknown. In this study, we invented a new reagent that improves the immunostaining of cortical microtubules and successfully visualized a parallel array of thick microtubules. During reorganization, they covered nearly the entire myoplasm cortical region, beneath the posterior-vegetal cortex. We designated this microtubule array as CAMP (cortical array of microtubules in posterior vegetal region). During the late phase of reorganization, CAMP shrank and the myoplasm formed a crescent-like cytoplasmic domain. When the CAMP formation was inhibited by sodium azide, myoplasmic reorganization and A-P axis formation were both abolished, suggesting that CAMP is important for these two processes
Isolation and characterization of cDNA clones for epidermis-specific and muscle-specific genes in Ciona savignyi embryos
Ascidian eggs and embryos have provided an appropriate experimental system to explore the cellular and molecular mechanisms involved in the embryonic cell specification and pattern formation of the embryo. In Japan, most of the studies of ascidian embryology have been carried out with the large eggs of Halocynthia roretzi. However, for future studies, Ciona species may provide a better experimental system, in particular with respect to the incorporation of genetic approaches. In order to establish Ciona as an experimental system, molecular markers with which to examine cellular differentiation are required. In the present study, we isolated and characterized cDNA clones for two epidermis-specific genes (CsEpi-1 and CsEpi-2) and for two muscle-specific genes (CsMA-1 and CsMu-1). CsEpi-1 encodes a polypeptide with three trefoil domains, while CsMA-1 encodes a muscle-type actin from C. savignyi Although CsEpi-2 and CsMu-1 transcripts seem to have a poly(A) tail at the 3' end, we could not find a distinct open reading frame in the sequences. Probes for CsEpi-1, CsMA-1 and CsMu-1 cross-reacted with C. intestinalis embryos. These cDNAs are useful as molecular markers for the specification of epidermis and muscle of Ciona embryos
Purification of mitochondrial proteins HSP60 and ATP synthase from ascidian eggs: implications for antibody specificity.
Use of antibodies is a cornerstone of biological studies and it is important to identify the recognized protein with certainty. Generally an antibody is considered specific if it labels a single band of the expected size in the tissue of interest, or has a strong affinity for the antigen produced in a heterologous system. The identity of the antibody target protein is rarely confirmed by purification and sequencing, however in many cases this may be necessary. In this study we sought to characterize the myoplasm, a mitochondria-rich domain present in eggs and segregated into tadpole muscle cells of ascidians (urochordates). The targeted proteins of two antibodies that label the myoplasm were purified using both classic immunoaffinity methods and a novel protein purification scheme based on sequential ion exchange chromatography followed by two-dimensional gel electrophoresis. Surprisingly, mass spectrometry sequencing revealed that in both cases the proteins recognized are unrelated to the original antigens. NN18, a monoclonal antibody which was raised against porcine spinal cord and recognizes the NF-M neurofilament subunit in vertebrates, in fact labels mitochondrial ATP synthase in the ascidian embryo. PMF-C13, an antibody we raised to and purified against PmMRF, which is the MyoD homolog of the ascidian Phallusia mammillata, in fact recognizes mitochondrial HSP60. High resolution immunolabeling on whole embryos and isolated cortices demonstrates localization to the inner mitochondrial membrane for both ATP synthase and HSP60. We discuss the general implications of our results for antibody specificity and the verification methods which can be used to determine unequivocally an antibody's target
Morphological Evidence for Novel Roles of Microtubules in Macrophage Phagocytosis
Although the phagocytic activity of macrophages has long been studied, the involvement of microtubules in the process is not well understood. In this study, we improved the fixation protocol and revealed a dynamically rearranging microtubule network in macrophages, consisting of a basal meshwork, thick bundles at the cell edge, and astral microtubules. Some astral microtubules extended beneath the cell cortex and continued to form bundles at the cell edge. These microtubule assemblies were mutually exclusive of actin accumulation during membrane ruffling. Although the stabilization of microtubules with paclitaxel did not affect the resting stage of the macrophages, it reduced the phagocytic activity and membrane ruffling of macrophages activated with serum-MAF, which induced rapid phagocytosis. In contrast, the destabilization of microtubules with nocodazole enhanced membrane ruffling and the internalization of phagocytic targets suggesting an inhibitory effect of the microtubule network on the remodeling of the actin network. Meanwhile, the microtubule network was necessary for phagosome maturation. Our detailed analyses of cytoskeletal filaments suggest a phagocytosis control system involving Ca2+ influx, the destabilization of microtubules, and activation of actin network remodeling, followed by the translocation and acidification of phagosomes on the microtubule bundles
Simultaneous Expression of Cancer Stem Cell-Like Properties and Cancer-Associated Fibroblast-Like Properties in a Primary Culture of Breast Cancer Cells
The importance of cancer-associated fibroblasts (CAFs) in cancer biology has been recently highlighted owing to their critical roles in cancer growth, progression, metastasis, and therapeutic resistance. We have previously established a primary culture of breast cancer cells, which showed epithelial-mesenchymal transition and cancer stem cell-like properties. In this study, we found that the primary culture also showed CAF-like properties. For example, hypoxia inducible factor 1α (HIF1A) and its downstream genes, nuclear factor-kappa B2 (NF-κB2) and BCL2/adenovirus E1B 19 kd-interacting protein 3 (BNIP3), and many enzymes involved in glycolysis, such as GAPDH, LDH, PGAM1, and PKM2, were highly overexpressed in the primary culture. Moreover, media conditioned with the primary culture cells enhanced the growth of breast cancer cells. Similar to previous CAF studies, this enhancement suggested to be occurred through fibroblast growth factor signaling. This MCKH primary culture cell, which showed simultaneous expression of tumorigenic and CAF properties, offers a unique experimental system for studying the biology of CAFs