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Introduction Syncytiotrophoblasts are the major components of the human placenta involved in fetal maternal exchange and hormone secretion. The syncytiotrophoblasts arise from the fusion of villous cytotrophoblasts. The cell cycle suppressor p57KIP2 is known to be an essential molecule for proper trophoblast differentiation during placental formation. Methods We generated p57KIP2-expressing BeWo transfectant cells. Proliferation assay and matrigel invasion assay were used to characterize p57KIP2-expressing BeWo transfectant cells. To reveal the role of p57KIP2 in syncytialization, we proceeded syncytium formation analysis and qRT-PCR for detection of the expression levels Syncytin-1, Syncytin-2 and their receptors. Results The human choriocarcinoma cell line, BeWo has undetectable levels of p57KIP2 expression. Expression of p57KIP2 reduced cell proliferation rate and extracellular matrix invasion activity. p57KIP2 expressing cells displayed multinucleated cells associated with syncytiotrophoblast differentiation. In the syncytialization event, p57KIP2 was found to potentiate forskolin-induced upregulation of Syncytin-2 in a cAMP-independent manner. Discussion These results indicate that the expression of p57KIP2 may act on the proliferation/invasion inhibitory factor and enhance the expression of Syncytin-2, which are associated with syncytialization in cytotrophoblasts.

A cyclin-dependent kinase (CDK) inhibitor, p57Kip2, is an important molecule involved in bone development; p57Kip2-deficient (p57-/-) mice display neonatal lethality resulting from abnormal bone formation and cleft palate. The modulator 1α,25-dihydroxyvitamin D3 (l,25-(OH)2VD3) has shown the potential to suppress the proliferation and induce the differentiation of normal and tumor cells. The current study assessed the role of p57Kip2 in the 1,25-(OH)2VD3-regulated differentiation of osteoblasts because p57Kip2 is associated with the vitamin D receptor (VDR). Additionally, 1,25-(OH)2VD3 treatment increased p57KIP2 expression and induced the colocalization of p57KIP2 with VDR in the osteoblast nucleus. Primary p57-/- osteoblasts exhibited higher proliferation rates with Cdk activation than p57+/+ cells. A lower level of nodule mineralization was observed in p57-/- osteoblasts than in p57+/+ cells. In p57+/+ osteoblasts, 1,25-(OH)2VD3 upregulated the p57Kip2 and opn mRNA expression levels, while the opn expression levels were significantly decreased in p57-/- cells. The osteoclastogenesis assay performed using bone marrow cocultured with 1,25-(OH)2VD3-treated osteoblasts revealed a decreased efficiency of 1,25-(OH)2VD3-stimulated osteoclastogenesis in p57-/- cells. Based on these results, p57Kip2 might function as a mediator of 1,25-(OH)2VD3 signaling, thereby enabling sufficient VDR activation for osteoblast maturation.

We examined whether chondroitin sulfates (CSs) exert inhibitory effects on heparanase (Hpse), the sole endoglycosidase that cleaves heparan sulfate (HS) and heparin, which also stimulates chemokine production. Hpse-mediated degradation of HS was suppressed in the presence of glycosaminoglycans derived from a squid cartilage and mouse bone marrow-derived mast cells, including the E unit of CS. Pretreatment of the chondroitin sulfate E (CS-E) with chondroitinase ABC abolished the inhibitory effect. Recombinant proteins that mimic pro-form and mature-form Hpse bound to the immobilized CS-E. Cellular responses as a result of Hpse-mediated binding, namely, uptake of Hpse by mast cells and Hpse-induced release of chemokine CCL2 from colon carcinoma cells, were also blocked by the CS-E. CS-E may regulate endogenous Hpse-mediated cellular functions by inhibiting enzymatic activity and binding to the cell surface.

Syncytiotrophoblasts are the major components of the human placenta involved in fetal maternal exchange and hormone secretion. The syncytiotrophoblasts arise from the fusion of villous cytotrophoblasts. The cell cycle suppressor p57We generated p57The human choriocarcinoma cell line, BeWo has undetectable levels of p57These results indicate that the expression of p57

Leukocyte migration is essential for exerting self-defense mechanisms. During the extravasation process, leukocytes transmigrate through the endothelial lining and the subendothelial basement membrane. Accumulating evidence supports the involvement of heparanase in this process. Altered cellular distribution resulting in relocalization of heparanase to the leading edge of migration is a key event to rapidly turn on the function of the enzyme during migration. This review presents current research investigating the cellular machinery that builds up a functional subcellular structure for leukocyte attachment to and degradation of the extracellular matrix. Recent advances in the understanding of the roles of heparanase in inflammatory diseases and pharmacological approaches to control heparanase-mediated actions during inflammation are also discussed.

Leukocyte migration is essential for exerting self-defense mechanisms. During the extravasation process, leukocytes transmigrate through the endothelial lining and the subendothelial basement membrane. Accumulating evidence supports the involvement of heparanase in this process. Altered cellular distribution resulting in relocalization of heparanase to the leading edge of migration is a key event to rapidly turn on the function of the enzyme during migration. This review presents current research investigating the cellular machinery that builds up a functional subcellular structure for leukocyte attachment to and degradation of the extracellular matrix. Recent advances in the understanding of the roles of heparanase in inflammatory diseases and pharmacological approaches to control heparanase-mediated actions during inflammation are also discussed.

Microbial metabolites have attracted increasing interest as a source of therapeutics and as probes for biological mechanisms. New microbial metabolites and derivatives targeted at inflammation and bone disease therapy have been identified by focusing on prostaglandin release, osteoblast differentiation and immune cell functions. These modulators of inflammatory processes and bone disease contribute to our understanding of biological mechanisms and support identification of the therapeutic potential of drug lead candidates. The present review describes recent advances in the chemistry and analysis of inhibitors of prostaglandin release or other functional molecules of immune cells, as well as inducers of osteoblast differentiation, including biological and pharmacological activities.The Journal of Antibiotics advance online publication, 1 November 2017; doi:10.1038/ja.2017.138.

To explore possible roles of heparanase in cancer-host crosstalk, we examined whether heparanase influences expression of inflammatory chemokines in colorectal cancer cells. Murine colorectal carcinoma cells incubated with heparanase upregulated MCP-1, KC, and RANTES genes and released MCP-1 and KC proteins. Heparanase-dependent production of IL-8 was detected in two human colorectal carcinoma cell lines. Addition of a heparanase inhibitor Heparastatin (SF4) did not influence MCP-1 production, while both latent and mature forms of heparanase augmented MCP-1 release, suggesting that heparanase catalytic activity was dispensable for MCP-1 production. In contrast, addition of heparin to the medium suppressed MCP-1 release in a dose-dependent manner. Similarly, targeted suppression of Ext1 by RNAi significantly suppressed cell surface expression of heparan sulfate and MCP-1 production in colon 26 cells. Taken together, it is concluded that colon 26 cells transduce the heparanase-mediated signal through heparan sulfate binding. We propose a novel function for heparanase independent of its endoglycosidase activity, namely as a stimulant for chemokine production.

We investigated the fate of proheparanase added to the culture media of mast cells. A recombinant protein mimicking proheparanase was continuously internalized into mastocytoma cells as well as bone marrow- and peritoneal cell-derived mast cells. Internalized heparanase molecules were accumulated in granules and a significant portion was released by stimulation with ionomycin, indicating that the internalized heparanase was sorted into secretory granules. The pro-form heparanase was processed into a mature and an active form inside the cells, in which intracellular heparin was fragmented by the mature enzyme. The internalization was substantially inhibited by addition of heparin and heparan sulfate to the culture medium, suggesting that glycosaminoglycan is involved in the uptake pathway. Out of four syndecans, expression of syndecan-3 and syndecan-4, especially cell surface syndecan-4, was detected in the mastocytoma cells. Two knockdown clones transfected with a shRNA expression vector targeting the syndecan-4 gene took up significantly lower amounts of heparanase than mock cells. We propose that some exogenous substances like proheparanase can be incorporated into mast cell granules via a glycosaminoglycan-mediated, especially syndecan-4-dependent, uptake pathway.

This corrects the article DOI: 10.1038/ja.2017.138.

Protein O-linked mannose β1,2-N-acetylglucosaminyltransferase 1 (POMGNT1) is a Golgi glycosyltransferase that catalyzes the formation of the N-acetylglucosamine (GlcNAc) β1→2Man linkage of O-mannosyl glycan. POMGNT1 is not modified by N-glycans because there are no potential N-glycosylation sites; however, it is not clear whether POMGNT1 is modified by O-glycans. To determine whether POMGNT1 is O-glycosylated, we prepared recombinant human POMGNT1 from HEK293T cells. The recombinant POMGNT1 was recognized by Sambucus sieboldiana lectin (SSA), and sialidase digestion of POMGNT1 decreased SSA reactivity and enhanced the reactivity of Arachis hypogaea lectin (PNA). These results suggest that POMGNT1 is modified by a sialylated core-1 O-glycan. Next, we analyzed the structures of the O-glycans on POMGNT1 by β-elimination and pyrazolone-labeling methods in combination with mass spectrometry. We identified several mucin-type O-glycans containing (NeuAc)1(Hex)1(HexNAc)1, (NeuAc)2(Hex)1(HexNAc)1, and (NeuAc)2(Hex)2(HexNAc)2. To examine whether the O-glycans affect the functions and properties of POMGNT1, we compared glycosylated and non-glycosylated forms of recombinant sPOMGNT1 for their activity and surface hydrophobicity using the hydrophobic probe 1-anilino-8-naphthalene sulfonate (ANS). POMGNT1 activity and surface hydrophobicity were not affected by the presence or absence of O-glycans.

Heparanase cleaves macromolecular heparin in the secretory granules of connective tissue-type mast cells. We investigated roles of the cleavage under a microenvironment mimicking where the mast cells physiologically reside. A connective tissue-type mast cell line MST and mouse peritoneal cell-derived mast cells stored macromolecular heparin in the secretory granules. The cells expressing heparanase stored fragmented heparin (~10 kDa) due to heparanase-dependent cleavage of the heparin. We produced an artificial collagen-based extracellular matrix and placed the live cells or glycosaminoglycans purified from the cells in the matrix to measure the release of sulfated macromolecules into the medium. The sulfate-radiolabelled molecules from the degranulating heparanase-expressing cells and the purified glycosaminoglycans showed significantly greater release into the medium than those derived from mock cells, which was not the case in suspension culture. The mast cell granular enzyme chymase, but not β-hexosaminidase, showed significantly greater release from the degranulating heparanase-expressing cells than from mock cells. Purified chymase mixed with fragmented heparin derived from heparanase-expressing cells showed greater release from collagen gels than the enzyme alone or mixed with macromolecular heparin derived from mock cells. We propose that the cleavage of macromolecular heparin by heparanase accelerates the release of heparin and chymase from extracellular matrices.

Local infiltration of inflammatory cells is regulated by a number of biological steps during which the cells likely penetrate through subendothelial basement membranes that contain heparan sulfate proteoglycans. In the present study, we examined whether administration of heparastatin (SF4), an iminosugar-based inhibitor of heparanase, could suppress local inflammation and degradation of heparan sulfate proteoglycans in basement membranes. In a carrageenan- or formyl peptide-induced dorsal air pouch inflammation model, the number of infiltrated neutrophils and monocytes was significantly lower in mice after topical administration of heparastatin (SF4). The concentration of chemokines MIP-2 and KC in pouch exudates of drug-treated mice was similar to control. In a zymosan-induced peritonitis model, the number of infiltrated cells was not altered in drug-treated mice. To further test how heparastatin (SF4) influences transmigration of inflammatory neutrophils, its suppressive effect on migration and matrix degradation was examined in vitro. In the presence of heparastatin (SF4), the number of neutrophils that infiltrated across a Matrigel-coated polycarbonate membrane was significantly lower, while the number of neutrophils passing through an uncoated membrane was not altered. Lysate of bone marrow-derived neutrophils released sulfate-radiolabeled macromolecules from basement membrane-like extracellular matrix, which was suppressed by heparastatin (SF4). Heparan sulfate degradation activity was almost completely abolished after incubation of lysate with protein G-conjugated anti-heparanase monoclonal antibody, strongly suggesting that the activity was due to heparanase-mediated degradation. Taken together, in a dorsal air pouch inflammation model heparastatin (SF4) potentially suppresses extravasation of inflammatory cells by impairing the degradation of basement membrane heparan sulfate.

Leukemia inhibitory factor (LIF) promotes the proliferation of neuronal progenitor cells in the cerebrum. However, it remains unclear how fetal LIF level is regulated. Here we show evidence that maternal LIF signals drive fetal LIF levels via the placenta, thereby promoting neurogenesis in the fetal brain in rats. Chronological changes showed that LIF concentration in fetal sera (FS) and fetal cerebrospinal fluid peaked at gestational day (GD) 15.5, after the peak of maternal LIF at GD14.5. LIF injection into rat dams at GD15.5 increased the level of ACTH in FS and subsequently increased LIF levels in FS and fetal cerebrospinal fluid. The elevation of fetal LIF after LIF injection into dams was inhibited by in utero injection of anti-ACTH antibody into fetuses. Cultured syncytiotrophoblasts, which express the LIF receptor and glycoprotein 130, were induced to secrete ACTH and up-regulate Pomc expression by the addition of LIF. Nucleated red blood cells from fetuses at GD15.5, but not GD13.5 or GD17.5, displayed LIF secretion in response to ACTH. Moreover, injection of LIF into dams at GD13.5 or GD17.5 did not result in elevation of ACTH or LIF in fetuses. The labeling index of 5-bromo-2′-deoxyuridine-positive cells in the ventricular zone of the cerebral neocortex increased 24 h after injection of LIF into dams at GD15.5 but not GD13.5 or GD17.5. These results suggest that in rats maternal LIF induces ACTH from the placenta, which in turn induces fetal nucleated red blood cells to secrete LIF that finally increases neurogenesis in fetuses around GD15.

The present report describes an anomalous case of the right vertebral artery arising as the last branch of the aortic arch identified in a 76-year-old Japanese male cadaver during dissection in the anatomical laboratory of Kanazawa Medical University. The aortic arch itself coursed normally but the right vertebral artery was uniquely situated at the fourth branch next to the brachiocephalic artery, the left common carotid artery, and the left subclavian artery. The anomalous right vertebral artery branched into the esophageal branch, the prevertebral branch, and the second right posterior intercostal artery, and finally entered the first costotransverse foramen at the thoracic region as it passed upward through the first to the seventh transverse foramina of the cervical vertebra. The left vertebral artery was normal. The development of the right vertebral artery may be described as follows: (i) the distal portion of the right dorsal aorta, which usually disappears, persisted and became united, via post-costal longitudinal anastomosis; (ii) the right dorsal aorta between the seventh and eighth intersegmental arteries lost its connection to the main structure; and (iii) the fusion of the originally paired dorsal aorta extended around the 11th segment, which was two segments away from the normal portion of the structure.

The authors recently demonstrated that the mitochondrial voltage-dependent anion channel 1 (VDAC1) is involved in the sensitivity of cancer cells to furanonaphthoquinone (FNQ). The aim of the present study was to investigate whether mitochondrial VDAC1 reduces quinone antitumor drugs. The VDAC1 purified by immunoprecipitation reduced FNQ in the presence of nicotinamide adenine dinucleotide (NADH) and produced H(2)O(2). Blue native polyacrylamide gel electrophoresis demonstrated that the band that reduced FNQ NADH-dependently mainly included VDAC1. Because H(2)O(2) generation in catalyzing FNQ with NADH caused mitochondrial damage, the cytotoxic activity of FNQ was induced by VDAC1. In the quinone antitumor drugs, menadione (VK3), adriamycin and mitomycin C, mitochondrial VDAC1 bioreductively activated VK3. These results demonstrate that mitochondrial VDAC1 is a pharmacologic target for the treatment of tumor.

Protein O-linked mannose β1,2-N-acetylglucosaminyltransferase 1 (POMGNT1) is a Golgi glycosyltransferase that catalyzes the formation of the N-acetylglucosamine (GlcNAc) β1→2Man linkage of O-mannosyl glycan. POMGNT1 is not modified by N-glycans because there are no potential N-glycosylation sites; however, it is not clear whether POMGNT1 is modified by O-glycans. To determine whether POMGNT1 is O-glycosylated, we prepared recombinant human POMGNT1 from HEK293T cells. The recombinant POMGNT1 was recognized by Sambucus sieboldiana lectin (SSA), and sialidase digestion of POMGNT1 decreased SSA reactivity and enhanced the reactivity of Arachis hypogaea lectin (PNA). These results suggest that POMGNT1 is modified by a sialylated core-1 O-glycan. Next, we analyzed the structures of the O-glycans on POMGNT1 by β-elimination and pyrazolone-labeling methods in combination with mass spectrometry. We identified several mucin-type O-glycans containing (NeuAc)1(Hex)1(HexNAc)1, (NeuAc)2(Hex)1(HexNAc)1, and (NeuAc)2(Hex)2(HexNAc)2. To examine whether the O-glycans affect the functions and properties of POMGNT1, we compared glycosylated and non-glycosylated forms of recombinant sPOMGNT1 for their activity and surface hydrophobicity using the hydrophobic probe 1-anilino-8-naphthalene sulfonate (ANS). POMGNT1 activity and surface hydrophobicity were not affected by the presence or absence of O-glycans.

Macrophage galactose-type C-type lectins (MGLs), which were recently named CD301, have 2 homologues in mice: MGL1 and MGL2. MGLs are expressed on macrophages and immature dendritic cells. The persistent presence of granulation tissue induced by a protein antigen was observed in wild-type mice but not in mice lacking an endogenous, macrophage-specific, galactose-type calcium-type lectin 1 (MGL1) in an air pouch model. The anti-MGL1 antibody suppressed the granulation tissue formation in wild-type mice. A large number of cells, present only in the pouch of MGL1-deficient mice, were not myeloid or lymphoid lineage cells and the number significantly declined after administration of interleukin 1 α (IL-1α) into the pouch of MGL1-deficient mice. Furthermore, granulation tissue was restored by this treatment and the cells obtained from the pouch of MGL1-deficient mice were incorporated into the granulation tissue when injected with IL-1α. Taken together, MGL1 expressed on a specific subpopulation of macrophages that secrete IL-1α was proposed to regulate specific cellular interactions crucial to granulation tissue formation.

The role of a macrophage galactose-type calcium-type lectin-1 (MGL1) in antigen-independent granulation tissue formation was investigated. Granulation tissue was induced by injection of carrageenan in an air pouch and distribution of macrophages expressing MGL1/2 was histologically examined. MGL1/2-positive cells were not observed in the granulation tissue induced by carrageenan though these cells were present in dermis. This was distinct from the fact that MGL1/2-positive cells were abundant in granulation tissue induced by antigenic stimulation. CD11b-positive cells were in dermis and carrageenan-induced granulation tissue. Because antigen-induced granulation tissue formation was previously shown to decrease in MGL1-deficient mice or after treatment with anti-MGL1 antibody, we investigated the effects of MGL1-deficient status on carrageenan-induced granulation tissue formation. The thickness of granulation tissue was almost identical between wild-type and MGL1-deficient mice. It is highly likely that MGL1-positive cells are not involved in tissue remodeling when inflammation is driven by nonspecific stimuli.

Cell surface lectins are known to regulate trafficking of cells in the immune system, yet the role of macrophage galactose-type C-type lectin 1 and 2 (MGL1/2) is poorly understood. In this study, antigen-specific chronic inflammation was induced in a subcutaneous air pouch model in mice, and distribution of cells expressing MGL1/2 was investigated. Azobenzenearsonate-conjugated acetylated BSA, used as an antigen, was introduced into an air pouch of immunized mice, and tissue formation and distribution of MGL1/2-positive cells in the sub-dermal regions was examined. Thickness of the inflammatory tissue and number of MGL1/2-positive cells simultaneously reached the maximum at day 4 and returned to the control level at day 6 or 8. When additional antigenic challenges were given, a chronic granulation tissue, which had two distinct layers, was generated. In the chronic tissue, CD11b-positive/MGL1/2-negative cells were abundant in the area close to the antigenic stimulus, while the area far from the antigenic stimulus was dominated by MGL1/2-positive/CD11b-negative or -low cells. Flow cytometric analyses of isolated cells from the granulation tissue revealed that MGL1/2-positive cells expressed MHC class II at high levels, CD11b at low levels but no CD11c. MGL1/2-positive and -negative fractions were separated from cells in the granulation tissue and a higher level of IL-1alpha messenger RNA than negative populations was detected in the MGL1/2-positive fraction by the semi-quantitative reverse transcription-PCR method. IL-1alpha production by MGL1/2-positive cells was also immunohistochemically detected. Results suggest that MGL1/2-positive cells represent a distinct sub-population of macrophages, having unique functions in the generation and maintenance of granulation tissue induced by antigenic stimuli.

In the sensitization phase of delayed-type hypersensitivity, dermal macrophages (MOs) expressing MO galactose-type C-type lectin1 (MGL1) are known to migrate from the dermis to lymph nodes (LNs), and this migration was previously suggested to be an essential process in the establishment of the immune response to peripheral antigens. We hypothesize that the interactions between MGL1 and its ligands determine the localization of MGL1/2-positive cells within the LNs. In the present report, distribution of MGL1 binding sites was immunohistochemically examined by means of biotinylated recombinant MGL1 and compared with the distribution of MGL1/2-positive cells after epicutaneous sensitization of the mice with fluorescein isothiocyanate. The binding sites of MGL1 were mainly detected on the subcapsular sinus, interfollicular regions, and the T/B boundary. The distribution overlapped with the area where MGL1/2-positive cells that had migrated from dermis localized after sensitization with the antigen.

Filoviruses cause lethal hemorrhagic disease in humans and nonhuman primates. An initial target of filovirus infection is the mononuclear phagocytic cell. Calcium-dependent (C-type) lectins such as dendritic cell- or liver/lymph node-specific ICAM-3 grabbing nonintegrin (DC-SIGN or L-SIGN, respectively), as well as the hepatic asialoglycoprotein receptor, bind to Ebola or Marburg virus glycoprotein (GP) and enhance the infectivity of these viruses in vitro. Here, we demonstrate that a recently identified human macrophage galactose- andN-acetylgalactosamine-specific C-type lectin (hMGL), whose ligand specificity differs from DC-SIGN and L-SIGN, also enhances the infectivity of filoviruses. This enhancement was substantially weaker for the Reston and Marburg viruses than for the highly pathogenic Zaire virus. We also show that the heavily glycosylated, mucin-like domain on the filovirus GP is required for efficient interaction with this lectin. Furthermore, hMGL, like DC-SIGN and L-SIGN, is present on cells known to be major targets of filoviruses (i.e., macrophages and dendritic cells), suggesting a role for these C-type lectins in viral replication in vivo. We propose that filoviruses use different C-type lectins to gain cellular entry, depending on the cell type, and promote efficient viral replication.

A novel mouse macrophage galactose-type C-type lectin 2 (mMGL2) was identified by BLAST analysis of expressed sequence tags. The sequence of mMGL2 is highly homologous to the mMGL, which should now be called mMGL1. The open reading frame of mMGL2 contains a sequence corresponding to a type II transmembrane protein with 332 amino acids having a single extracellular C-type lectin domain. The 3'-untranslated region included long terminal repeats of mouse early transposon. The Mgl2 gene was cloned from a 129/SvJ mouse genomic library and sequenced. The gene spans 7,136 base pairs and consists of 10 exons, which is similar to the genomic organization of mMGL1. The reverse transcriptase-PCR analysis indicates that mMGL2 is expressed in cell lines and normal mouse tissues in a macrophage-restricted manner, also very similar to that of mMGL1. The mMGL2 mRNA was also detected in mMGL1-positive cells, which were sorted from thioglycollate-induced peritoneal cells with a mMGL1-specific monoclonal antibody, LOM-8.7. The soluble recombinant proteins of mMGL2 exhibited carbohydrate specificity for alpha- and beta-GalNAc-conjugated soluble polyacrylamides, whereas mMGL1 preferentially bound Lewis X-conjugated soluble polyacrylamides in solid phase assays. These two lectins may function cooperatively as recognition and endocytic molecules on macrophages and related cells.

Lectins on antigen presenting cells are potentially involved in the antigen uptake and the cellular recognition and trafficking. Serial analysis of gene expression in monocyte-derived dendritic cells (DCs), monocytes, and macrophages revealed that 7 of the 19 C-type lectin mRNA were present in immature DCs. Two of these, the macrophage mannose receptor and the macrophage lectin specific for galactose/N-acetylgalactosamine (MGL), were found only in immature DCs, as confirmed by reverse transcriptase-PCR and flow cytometric analysis. By subcloning and sequencing the amplified mRNA, we obtained nucleotide sequences encoding seven different human MGL (hMGL) subtypes, which were apparently derived from alternatively spliced mRNA. In addition, the hMGL gene locus on human chromosome 17p13 contains one gene. A single nucleotide polymorphism was identified at a position in exon 3 that corresponds to the cytoplasmic region proximal to the transmembrane domain. Of all the splicing variants, the hMGL variant 6C was expressed at the highest levels on immature DCs from all donors tested. Immature DCs could incorporate alpha-GalNAc-modified soluble acrylamide polymers, and this was significantly inhibited by pretreatment of the cells with an anti-hMGL monoclonal antibody that blocks the lectin-carbohydrate interaction. We propose that hMGL is a marker of imDCs and that it functions as an endocytic receptor for glycosylated antigens.

Fibroblastic tissue is an important component of malignant tumors, involved in the establishment of metastatic foci from micrometastases, and thought to prevent invasion of metastatic tumor cells into surrounding tissue. However, experimental models of fibrosis during the growth of micrometastasis into established metastases were not previously available. In the present paper, we performed immunohistochemical studies on experimental hepatic metastasis with colon 38 mouse colon carcinoma cells injected into syngeneic C57BL/6 mice. Early and late stages of metastatic nodules were examined for the distribution of endothelial cells, fibroblasts, and macrophages by the use of markers of these cells. One week after intrasplenic injection of colon 38 cells, micrometastases mainly appeared in the region of sinusoids accompanied with invasion of F4/80-positive Kupffer cells. Transitional metastases can be defined based on the histological appearance and intensive infiltration of both macrophages and fibroblasts. These transitional metastases were connected by protrusions of fibroblast-rich tissues co-localized with collagen-rich matrix and CD31-positive cells. This protrusion preceded fibrosis formation characteristics to established metastases associated with angiogenesis and segregation of tumor cells from host cells. Three stages can thus be classified during the development of hepatic metastasis in this syngeneic experimental system: micrometastasis, transitional metastasis, and established metastasis.

Dermal cells expressing a macrophage C-type lectin (mMGL) were previously suggested to migrate to regional lymph nodes during the sensitization phase of delayed-type hypersensitivity (DTH). The migration seemed to be induced by the solvent used to dissolve the antigen, and the DTH response was significantly enhanced by the migration. In this study, immunohistochemical analysis of skin after epicutaneous application of one of such solvents, a mixture of acetone and dibutylphthalate (AD), revealed a transient decrease in the number of mMGL-positive cells in the dermis. A similar decrease in this cell population was also observed in an ex vivo assay with skin explants excised from AD-treated sites. Conditioned medium from organ culture of AD-treated skin induced a similar decrease of mMGL-positive cells in untreated dermis, indicating the involvement of soluble factors. mMGL-positive cells seemed to represent a unique subpopulation of F4/80-positive dermal cells.

We established a hybridoma clone 1N1 that produced a monoclonal antibody to stain the apical portion of frog taste cells, by directly immunizing taste discs of the bullfrog (Rana catesbeiana) without any dispersion procedure of the taste organ. The antibody stained discrete regions on the surface of the taste discs, but did not stain the epithelium sheet of the tongue devoid of taste discs. The antibody stained approximately 93% of the taste discs tested (172/184) derived from nine frogs, showing that distribution of the antigen was common to most of the taste discs. The following observations strongly suggested that the antibody recognized a certain antigen on the apical membrane of the taste cells. (i) The antibody selectively stained cross points of intermucus areas on the surface of the taste disc. Neither the mucus cells nor the wing cells that mainly cover the surface were stained with the antibody. (ii) Dispersed taste cells were prepared by calcium ion chelating and subsequently by collagenase treatment to avoid digestion of the antigen. The antibody stained the apical end of the taste cells.

Cytotoxic properties of human activated macrophages were investigated by measuring both 51 Cr and [ 3 H]TdR releases from prelabeled target cells. The kinetic study of macrophage-mediated cytotoxicity indicated that 51 Cr and [ 3 H]TdR releases showed a distinct time course. Next, when [ 3 H]TdR release was measured as a parameter for cytotoxicity, pretreatment of activated macrophages with either actinomycin D or emetine remarkably decreased their cytotoxicity in a dose-dependent manner. In contrast, the pretreatment with these inhibitors had little effect on 51 Cr release. Furthermore, the addition of Zn 2+ in the assay medium caused the decrease in [ 3 H]TdR release but not 51 Cr release from the target cells. Taken together, our findings indicate that 51 Cr and [ 3 H]TdR releases from the target cells are induced by activated macrophages through different cytotoxic mechanisms; the former does not require RNA and protein syntheses in macrophages during coculture, whereas the latter requires them. Our findings also suggest that macrophage-derived nuclease may play an important role for inducing [ 3 H]TdR release from the target cells.

Macrophages are activated by a two-step mechanism involving at least two kinds of factors, a priming and a triggering factor, to become cytotoxic to various tumor cells. In the present study, we purified macrophage-activating factor for cytotoxicity I (MAF-C I), defined as a priming macrophage activating factor (MAF), by about 1,600-fold from the culture supernatant of a human T cell hybridoma, H3-E9-6, by a series of chromatographic procedures. We identified MAF-C I activity released from H3-E9-6 cells as interleukin-2 (IL-2) from the following findings. (i) The physicochemical properties of MAF-C I and IL-2 were almost identical. (ii) Purified MAF-C I active fraction also showed T cell proliferating activity. (iii) MAF-C I activity in the purified fraction was completely neutralized by anti-IL-2 antibodies. (iv) Human recombinant IL-2 (rIL-2), at a suboptimal dose, and lipopolysaccharide (LPS) synergistically induced monocyte-mediated cytotoxicity.

The tandem use of the photosensitive bola-amphiphile 1 (X=3 H) and cholesterol enabled the determination of the center of the transmembrane domain of glycophorin A (131 amino acid residues) in a membrane by selective functionalization of the protein within a phospholipid bilayer.

Tumor necrosis factor (TNF) has been shown to be cytotoxic to tumor cell lines in vitro, but the mechanism by which TNF exerts its cell growth-regulatory effects is not known. In this report, we used various inhibitors to investigate the sequence of events that lead to cytotoxic effects of TNF on L.P3 cells, a highly sensitive, murine fibroblast cell line. Our results indicate that mitochondrial respiration chains are damaged by a hydroxyl radical at an early stage of the cell lysis after TNF treatment. This event is followed by the activation of phospholipase A2, and finally leads to cell lysis.

O-glycosylation of mucin is initiated by the attachment of N-acetyl-D-galactosamine (GalNAc) to serine or threonine residues in mucin core polypeptides by UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases (ppGalNAc-Ts). It is not well understood how GalNAc attachment is regulated by multiple ppGalNAc-Ts in each cell. In the present study, the expression levels of murine ppGalNAc-Ts (mGalNAc-Ts), T1, T2, T3, T4, T6, and T7 were compared between mouse colon carcinoma colon 38 cells and variant SL4 cells, selected for their metastatic potentials, by using the competitive RT-PCR method. The expression levels of mGalNAc-T1, T2, and T7 were slightly higher in the SL4 cells than in the colon 38 cells, whereas the expression level of mGalNAc-T3 in the SL4 cells was 1.5% of that in the colon 38 cells. Products of enzymatic incorporations of GalNAc residues into FITC-PTTTPITTTTK peptide by the use of microsome fractions of these cells as the enzyme source were separated and characterized for the number of attached GalNAc residues and their positions. The maximum number of attached GalNAc residues was 6 and 4 when the microsome fractions of the colon 38 cells and SL4 cells were used, respectively. When the microsome fractions of the colon 38 cells were treated with a polyclonal antibody raised against mGalNAc-T3, the maximum number of incorporated GalNAc residues was 4. These results strongly suggest that mGalNAc-T3 in colon 38 cells is involved in additional transfer of GalNAc residues to this peptide.

Twenty-three human colorectal carcinoma cell lines were examined for the binding of recombinant hepatic asialoglycoprotein receptor 1 (ASGR1), which is known to be exclusively expressed on hepatic parenchymal cells. The effects of the binding were assessed by adhesion to and proliferation on immobilized recombinant ASGR1. Recombinant ASGR1 bound strongly to six cell lines and moderately to 15 cell lines out of 23 lines tested, as shown by flow cytometric analysis. The first six cell lines (group A) also exhibited strong adherence to immobilized ASGR1, whereas 11 of the 15 cell lines of the second group (group B) showed significant adhesion with smaller enhancement by ASGR1 than the cell lines in group A. With a representative cell line (DLD-1 cells categorized in group B), a significant portion of the adhesion was inhibited by preincubation of ASGR1 with asialofetuin, a competitive inhibitor of the carbohydrate recognition by ASGR1. The growth rates of 13 cell lines (two of group A and 11 of group B) were significantly accelerated when they were cultured on immobilized recombinant ASGR1. The results indicate that ASGR is a potential organ-specific microenvironmental factor for colorectal carcinoma growth and metastasis formation in livers.

Although the celiac artery is a common trunk of the left gastric, splenic, and common hepatic arteries, its branching pattern varies. Indeed, even among anatomy textbooks, there is disagreement on which pattern is standard. In the present study, we identified the standard pattern of celiac artery branching by examining 186 Japanese cadavers. Celiac arteries with the three main branches were found in 91.4% (170/186) of the cadavers. These 170 cases were then classified into 4 types (Types I-IV). Type I, in which the first branch was the left gastric artery, accounted for 132 cases (71.0%). Thirty-one cases (16.7%) were Type II, in which the three main arteries branched out at the same vertebral level. Type III, in which the common hepatic artery was the first branch, accounted for 4 cases (2.2%). Finally, 3 cases (1.6%) were Type IV, in which the splenic artery was the first branch. These findings suggest that the Type I phenotype is the standard branching pattern of the celiac artery in Japanese. The artery's developmental process was also discussed.

We compared the tumoricidal activity of human monocytes cultured with interleukin-2 (IL-2) or human recombinant interferon-gamma (IFN-gamma) alone, or IFN-gamma in combination with a small amount of lipopolysaccharides (LPS). Human monocytes cultured with IL-2 for 7 days or longer, termed lymphokine-activated macrophages (LAMs), showed higher tumoricidal activity than those cultured for 1 day. In contrast, monocytes cultured with IFN-gamma alone or in combination with LPS for 7 days or longer showed lower tumoricidal activity. LAMs were identified as macrophages by nonspecific esterase staining and immunofluorescence staining with anti-CD14 antibody. LAMs were not induced in fetal calf serum-containing medium, but they were induced when colony-stimulating factor-1 was added to the medium. LAMs showed high tumoricidal activity against all human and murine tumor cell lines tested, although they showed no cytotoxic activity against human normal cells. During incubation with IL-2, tumoricidal activity of LAMs was maximal at days 8-16 and was sustained until day 28. The difference in tumoricidal mechanism between LAMs and lymphokine-activated killer (LAK) cells was also shown by using two kinds of cytotoxic assay systems. LAMs require a long incubation time to kill tumor cells, but LAK cells can kill them immediately. Furthermore, LAMs kill tumor cells with complete DNA degradation, whereas LAK cells can induce significant but not complete DNA degradation. These results indicate that LAMs and LAK cells have different tumoricidal mechanisms for killing target cells, although they were induced by incubation with the same lymphokine, IL-2.

Degradation of extracellular matrix is associated with extravasation of metastatic tumor cells and inflammatory cells. Heparanase, the heparan sulfate-specific endo-beta-glucuronidase, is a key enzyme for the matrix degradation, yet its involvement in extravasation and invasion during pathological processes was not fully clarified in vivo. In the present study, we examined heparanase expression in mouse experimental models, lung metastasis of melanoma and skin infiltration of neutrophils. Sixteen novel monoclonal antibodies specific for mouse heparanase were established by enzyme-linked immunosorbent assay with a recombinant mouse proheparanase, immunocytochemical staining of B16F10 melanoma cells cultured in vitro, and immunoprecipitation of the lysate of heparanase transfectant cells. Heparanase expression in metastatic nodules of B16F10 melanoma cells and in neutrophils localized in the inflamed skin was immunohistochemically detected using a monoclonal antibody RIO-1 that recognized the C-terminus of mouse heparanase. Homogeneous and strong heparanase staining was observed in 46% of the lung micrometastases of B16F10 melanoma cells. The staining was intensely positive on the invasive front of larger established metastasis nodules, but it was weak or heterogeneous inside the nodules. Heparanase expression in skin-infiltrating neutrophils was examined after inducing local inflammation with croton oil. The monoclonal antibody stained a significant portion of neutrophils inside and along the blood vessels, whereas it did not stain dermal neutrophils located distant from the vasculatures. The present study strongly suggests that both melanoma cells and neutrophils transiently express heparanase before and during the invasive process in vivo.

Recent studies in rodents suggest that maternal immune activation (MIA) by viral infection is associated with schizophrenia and autism in offspring. Although maternal IL-6 is though t to be a possible mediator relating MIA induced these neuropsychiatric disorders, the mechanism remains to be elucidated. Previously, we reported that the maternal leukemia inhibitory factor (LIF)-placental ACTH-fetal LIF signaling relay pathway (maternal-fetal LIF signal relay) promotes neurogenesis of fetal cerebrum in rats. Here we report that the maternal-fetal LIF signal relay in mice is suppressed by injection of polyriboinosinic-polyribocytidylic acid into dams, which induces MIA at 12.5 days post-coitum. Maternal IL-6 levels and gene expression of placental suppressor of cytokine signaling 3 (Socs3) increased according to the severity of MIA and gene expression of placental Socs3 correlated with maternal IL-6 levels. Furthermore, we show that MIA causes reduction of LIF level in the fetal cerebrospinal fluid, resulting in the decreased neurogenesis in the cerebrum. These findings suggest that maternal IL-6 interferes the maternal-fetal LIF signal relay by inducing SOCS3 in the placenta and leads to decreased neurogenesis.

Monoclonal antibodies (mAbs) specific for the human macrophage galactose-type calcium-type lectin (MGL) were established. The recombinant extracellular domain of MGL was used to immunize a mouse, and 10 hybridoma clones were obtained. Binding of recombinant MGL to asialo-bovine submaxillary mucin was shown to be blocked by mAbs MLD-1, 4 and 6. Immunoprecipitation of MGL from lysates of COS-1 cells transfected with MGL cDNA (form 6A) was achieved with mAbs MLD-1, 4, 7, 8 and 16. Chimeric recombinant proteins between human MGL and mouse MGL1 were used to determine the location of the epitopes for these mAbs. mAbs MLD-8, 13, 15 and 16 interacted with the amino terminal side of the conserved WVDGTD sequence immediately upstream of QPD, whereas mAbs MLD-7, 12 and 17 interacted with the other side. mAbs MLD-1, 4, and 6 apparently required both sides of this boundary. mAbs MLD-15 and 16 were shown to recognize the protein products of alternatively spliced mRNA 6A/8A and 6C/8A, having deletions at the boundary of exons 7 and 8, in addition to full length and other spliced forms of MGL (6A, 6B and 6C), whereas the other mAbs bound only full length and forms 6A, 6B and 6C.

In the sensitization phase of contact hypersensitivity in mice, dermal macrophages (MOs) expressing MO galactose-type C-type lectin1 (MGL1) are known to migrate from the dermis to lymph nodes (LNs) where they accumulate in the subcapsular sinus, interfollicular regions, and areas surrounding high endothelial venules. We hypothesize that the interactions between MGL1 and its ligands determine the localizations of MGL1-positive cells within the LNs. In the present study, our major aim was to isolate MGL1 counter-receptor(s) from lysates of LNs using affinity chromatography with immobilized recombinant MGL1. Fractions bound and eluted with EDTA were analyzed by SDS-PAGE and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. One of the predominant components was sialoadhesin (Sn, Siglec-1). Sn from lysates of LNs was immobilized on microtiter plates precoated with anti-Sn monoclonal antibody, and binding of recombinant MGL1 and adhesion of cells expressing MGL1 were tested. The binding of recombinant MGL1 to Sn was shown to be dependent on Ca2+ and N-glycans on Sn. MGL1-transfected Chinese hamster ovary cells adhered to the Sn-coated plates, whereas mock transfectants did not. Immunohistochemical localization of anti-Sn monoclonal antibody in LN coincided with the subcapsular sinus area to which recombinant MGL1 was bound. Furthermore, the distribution of MGL1+ cells after sensitization with FITC was demonstrated to overlap with that of Sn within the subcapsular sinus of draining LNs. These results suggest that Sn acts as an endogenous counter-receptor for MGL1.

Extravasation of peripheral blood monocytes through vascular basement membranes requires degradation of extracellular matrix components including heparan sulfate proteoglycans (HSPGs). Heparanase, the heparan sulfate-specific endo-β-glucuronidase, has previously been shown to be a key enzyme in melanoma invasion, yet its involvement in monocyte extravasation has not been elucidated. We examined a potential regulatory mechanism of heparanase in HSPG degradation and transmigration through basement membranes in leukocyte trafficking using human promonocytic leukemia U937 and THP-1 cells. PMA-treated cells were shown to degrade 35S-sulfated HSPG in endothelial extracellular matrix into fragments of an approximate molecular mass of 5 kDa. This was not found with untreated cells. The gene expression levels of heparanase or the enzyme activity of the amount of cell lysates were no different between untreated and treated cells. Immunocytochemical staining with anti-heparanase mAb revealed pericellular distribution of heparanase in PMA-treated cells but not in untreated cells. Cell surface heparanase capped into a restricted area on PMA-treated cells when they were allowed to adhere. Addition of a chemoattractant fMLP induced polarization of the PMA-treated cells and heparanase redistribution at the leading edge of migration. Therefore a major regulatory process of heparanase activity in the cells seems to be surface expression and capping of the enzyme. Addition of the anti-heparanase Ab significantly inhibited enzymatic activity and transmigration of the PMA-treated cells, suggesting that the cell surface redistribution of heparanase is involved in monocyte extravasation through basement membranes.

Fibroblastic tissue is an important component of malignant tumors, involved in the establishment of metastatic foci from micrometastases, and thought to prevent invasion of metastatic tumor cells into surrounding tissue. However, experimental models of fibrosis during the growth of micrometastasis into established metastases were not previously available. In the present paper, we performed immunohistochemical studies on experimental hepatic metastasis with colon 38 mouse colon carcinoma cells injected into syngeneic C57BL/6 mice. Early and late stages of metastatic nodules were examined for the distribution of endothelial cells, fibroblasts, and macrophages by the use of markers of these cells. One week after intrasplenic injection of colon 38 cells, micrometastases mainly appeared in the region of sinusoids accompanied with invasion of F4/80-positive Kupffer cells. Transitional metastases can be defined based on the histological appearance and intensive infiltration of both macrophages and fibroblasts. These transitional metastases were connected by protrusions of fibroblast-rich tissues co-localized with collagen-rich matrix and CD31-positive cells. This protrusion preceded fibrosis formation characteristics to established metastases associated with angiogenesis and segregation of tumor cells from host cells. Three stages can thus be classified during the development of hepatic metastasis in this syngeneic experimental system: micrometastasis, transitional metastasis, and established metastasis.

We studied the expression of a human macrophage lectin specific for galactose/N-acetylgalactosamine (hMGL) during macrophage differentiation. The expression of hMGL during the in vitro differentiation induced by human serum was examined by immunostaining and Western blotting with a specific mAb, MLD-1, as well as with RT-PCR analysis. hMGL was detected on cells at an intermediate stage of differentiation. These cells were round, slightly larger in size (12.7 +/- 0.2 microm) than monocytes (9.8 +/- 0.1 microm) and expressed the macrophage marker CD14, but lacked the dendritic cell marker CD1a. The highest levels of expression occurred after 2-4 days of culture. At this time point, MLD-1 prominently stained 20-40% of the cells. Monocytes cultured for 16 h or fully differentiated monocyte-derived macrophages were negative or weak for hMGL expression. Similar transient expression was also observed during granulocyte macrophage colony stimulating factor- or macrophage colony stimulating factor-dependent macrophage differentiation. The lectin was characterized as a functional endocytic receptor for glycosylated macromolecules, since the uptake of carbohydrate polymers was partially inhibited by the addition of MLD-1. The distribution of hMGL(+) cells in normal human skin was found by immunostaining to be mainly in the upper dermis distant from vascular structures. More than 90% of the hMGL(+) cells were double stained with anti-CD68 mAb and constituted approximately 20% of the CD68(+) cells. We suggest that the dermal hMGL(+) cells are a subset of differentiated cells derived from monocytes and that hMGL is a unique marker for cells at an intermediate stage of macrophage differentiation.

We have developed a chemical method for directly identifying the amino acid residues of the transmembrane domain of a protein that are located right in the center of the membrane. Glycophorin A (GPA), the major sialoglycoprotein of human erythrocytes, was the first membrane protein whose primary sequence was elucidated, but its three-dimensional structure is still not known. GPA has been reconstituted into liposomes formed from dimyristoylphosphatidylcholine, dimyristoylphosphatidylserine, cholesterol, and a bola-amphiphilic phospholipidic photoactivatable probe (radioactive probe 1) by a detergent-mediated method. Electron microscopy confirmed the formation of spherical vesicular structures, and sucrose-density gradients revealed that the proteoliposomes comprised only one membrane fraction. Proteinase-K digestion of GPA in the proteoliposomes suggested that the orientation of GPA in reconstituted proteoliposomes was virtually identical to that observed in natural erythrocyte membranes. After photo-irradiation of the reconstituted proteoliposomes and in situ tryptic digestion, the photolabeled amino acid residues were analyzed by Edman degradation and their radioactivity was measured. Val80 and Met81, which had been assumed to be located near the center of the transmembrane domain of GPA, were indeed highly selectively photolabeled by probe 1. The new method might be applied to analyze the three-dimensional arrangement of the transmembrane domain of protein complexes that are made up from several subunits.

The mechanism by which dermal cells expressing a macrophage calcium-type lectin (MGL) trafficked to regional lymph nodes was investigated. Conditioned medium prepared from organ cultures of mouse skin sensitized with a mixture of acetone and dibutylphthalate was shown to decrease the number of MGL(+) cells in the dermis in ex vivo organ culture assays. In in vitro culture of sensitized skin, the loss of MGL(+) cells was abrogated by the addition to the culture medium of mAb against IL-1ss, while addition of recombinant IL-1ss to the medium in which untreated skin was cultured induced loss of MGL(+) cells. Intradermal injection of recombinant IL-1ss also resulted in a transient increase of MGL(+) cells in the T cell area of draining lymph nodes in vivo, indicating that IL-1ss is central in the entire process of MGL(+) cell trafficking to the lymph nodes. Supporting this is that cells producing IL-1ss were detected in the epidermis of cultured skin even early after sensitization. The possibility that IL-1ss simply down-regulates MGL expression was eliminated by Western blotting experiments with isolated MGL(+) cells treated with or without IL-1ss. IL-1alpha and tumor necrosis factor (TNF)-alpha were also able to induce migration of MGL(+) cells in the ex vivo assay in a manner akin to IL-1ss, and antibodies against them abrogated this. Isolated MGL(+) cells from skin cultured in type I collagen matrix in vitro displayed morphological changes upon exposure to IL-1ss, IL-1alpha or TNF-alpha, indicating that these cytokines exert a direct effect on these cells. Thus, pro-inflammatory cytokines, particularly IL-1ss, are produced at the site of skin sensitization and are involved in at least initiating the trafficking of cells expressing MGL to the lymph nodes.