Publications by authors named "Kenji Uchimura"

Spinal cord injury (SCI) damages neural circuits and triggers pro-inflammatory responses, resulting in locomotor impairment. The carbohydrate sulfotransferases GlcNAc6ST1 and GlcNAc6ST4 modulate the function of blood monocytes and microglia. However, their specific roles and enzymatic relationships in neuroinflammation and functional recovery after SCI remain unclear.

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Spinal cord injury (SCI) results in damage to neural circuits that cause long-term locomotor and sensory disability. The objective of the present study is to evaluate whether a clinical drug, protamine, can be employed as a therapeutic agent for SCI. First, we examined the rescue effect of protamine on dystrophic endballs (DEs) cultured on a chondroitin sulfate (CS) gradient coating.

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The tumor suppressor TP53 gene, the most frequently mutated gene in human cancers, produces the product tumor protein p53, which plays an essential role in DNA damage. p53 protein mutations may contribute to tumorigenesis by loss of tumor suppressive functions and malignancy of cancer cells via gain-of-oncogenic functions. We previously reported that mutant p53 proteins form aggregates and that cytoplasmic p53 aggregates were associated with poor prognosis in human ovarian cancer.

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We recently showed that 6-sulfo sialyl -acetyllactosamine (LacNAc) in -linked glycans recognized by the CL40 antibody is abundant in the pleural mesothelium under physiological conditions and that these glycans undergo complementary synthesis by GlcNAc6ST2 (encoded by ) and GlcNAc6ST3 (encoded by ) in mice. GlcNAc6ST3 is essential for the synthesis of R-10G-positive keratan sulfate (KS) in the brain. The predicted minimum epitope of the R-10G antibody is a dimeric asialo 6-sulfo LacNAc.

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Article Synopsis
  • * Research demonstrated that while A2-17 undergoes a coil-to-helix transition upon binding to lipid membranes, its constrained analogs do not penetrate cells effectively; StchA2-17 remains on the cell surface.
  • * The study concludes that the structural flexibility of A2-17 enhances its ability to perturb lipid membranes and induce charge influx, contributing to its superior cell penetration ability.
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Recent studies suggested that aggregates of mutant p53 proteins may propagate and impair normal p53 functioning in recipient cells. Our previous study showed that cancer cell-derived p53 aggregates that cells internalized interfered with p53-dependent apoptosis in recipient cells. However, involvement of p53 aggregate propagation in cancer pathology has not been fully elucidated.

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High endothelial venules (HEVs) are specialized blood vessels that support the migration of lymphocytes from the bloodstream into lymph nodes (LNs). They are also formed ectopically in mammalian organs affected by chronic inflammation and cancer. The recent arrival of immunotherapy at the forefront of many cancer treatment regimens could boost a crucial role for HEVs as gateways for the treatment of cancer.

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Article Synopsis
  • Sialyl 6-sulfo Lewis X (6-sulfo sLe) and its derivative are important glycans found in high endothelial venules of lymphoid organs, with implications in allergic and asthmatic lung conditions.
  • The CL40 antibody identifies specific glycan structures that require both sialylation and GlcNAc-6-sulfation, revealing their presence in normal mouse lung tissues.
  • GlcNAc6ST2 and GlcNAc6ST3 are crucial for the production of CL40-positive glycans in the lung mesothelium, and their combined expression is necessary for proper in vivo glycan manifestation.
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Dysregulation of amyloidogenic proteins and their abnormal processing and deposition in tissues cause systemic and localized amyloidosis. Formation of amyloid β (Aβ) fibrils that deposit as amyloid plaques in Alzheimer's disease (AD) brains is an earliest pathological hallmark. The polysulfated heparan sulfate (HS)/heparin (HP) is one of the non-protein components of Aβ deposits that not only modulates Aβ aggregation, but also acts as a receptor for Aβ fibrils to mediate their cytotoxicity.

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Article Synopsis
  • Researchers developed a peptide called A2-17, known for its ability to penetrate cell membranes, and studied its effectiveness using three structural variations.
  • They found that the efficiency of cell penetration is linked to the peptide's hydrophobic moment, particularly noting that the isomer A2-17 L14R/R15L has the highest hydrophobic moment and penetrates deeper into membranes.
  • The study demonstrated that while A2-17 L14R/R15L causes significant membrane damage, optimal perturbation of the membrane is essential for efficient cell entry without creating stable pores.
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Sulfs represent a class of unconventional sulfatases which provide an original post-synthetic regulatory mechanism for heparan sulfate polysaccharides and are involved in multiple physiopathological processes, including cancer. However, Sulfs remain poorly characterized enzymes, with major discrepancies regarding their in vivo functions. Here we show that human Sulf-2 (HSulf-2) harbors a chondroitin/dermatan sulfate glycosaminoglycan (GAG) chain, attached to the enzyme substrate-binding domain.

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Article Synopsis
  • Keratan sulfate (KS) glycan is an important component of proteoglycans found in the adult brain, particularly near perineuronal regions of neurons.
  • Previous research indicated that the production of KS is dependent on enzymes GlcNAc6ST3 and GlcNAc6ST1, with deficiencies in these enzymes leading to a complete lack of KS.
  • This study identifies Beta3Gn-T7 as a key enzyme for synthesizing KS in the adult brain, particularly in oligodendrocyte lineage cells, suggesting its role in forming structures like neuropils and perineuronal nets.
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C-Mannosylation is a rare type of protein glycosylation and is reportedly critical for the proper folding and secretion of parental proteins. Still, the effects of C-mannosylation on the biological functions of these modified proteins remain to be elucidated. The Trp-x-x-Trp (WxxW) sequences, whose first tryptophan (Trp) can be C-mannosylated, constitute the consensus motifs for this glycosylation modification and are commonly found in thrombospondin type 1 repeats that regulate molecular functions of thrombospondin 1 in binding and activation of transforming growth factor β (TGF-β).

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Aging changes the mechanical properties of brain tissue, such as stiffness. It has been proposed that the maintenance and differentiation of neural stem cells (NSCs) are regulated in accordance with extracellular stiffness. Neurogenesis is observed in restricted niches, including the dentate gyrus (DG) of the hippocampus, throughout mammalian lifetimes.

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Intrahepatic bile ducts transport bile between bile canaliculi and the extrahepatic bile duct. The luminal surface of this tract is lined by a layer of biliary epithelial cells, or cholangiocytes, which secrete mucins consisting of scaffold proteins and -glycosidically linked carbohydrate side chains. Although mucin core proteins have been extensively investigated, the structure and function of carbohydrate side chains have not.

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High endothelial venules (HEVs) effectively recruit circulating lymphocytes from the blood to lymph nodes. HEVs have endothelial cells (ECs) and perivascular sheaths consisting of fibroblastic reticular cells (FRCs). Yet, post-luminal lymphocyte migration steps are not well elucidated.

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Article Synopsis
  • Mutants of the tumor suppressor protein p53 can form protein aggregates that may spread in a manner similar to prions, though the exact process isn't fully understood.
  • Recent research has shown that sulfated glycosaminoglycans, particularly the highly sulfated regions of heparan sulfate (called S-domains), play a role in cancer by facilitating the spread of these p53 aggregates between cells.
  • This study highlights a potential mechanism by which p53 aggregation contributes to cancer progression, suggesting a process that involves specific molecular interactions.
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Cancer patients with malignant involvement of tumor-draining lymph nodes (TDLNs) and distant metastases have the poorest prognosis. A drug delivery platform that targets the primary tumor, TDLNs, and metastatic niches simultaneously, remains to be developed. Here, we generated a novel monoclonal antibody (MHA112) against peripheral node addressin (PNAd), a family of glycoproteins expressed on high endothelial venules (HEVs), which are present constitutively in the lymph nodes (LNs) and formed ectopically in the tumor stroma.

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Sulfated glycosaminoglycans (GAGs) such as heparan sulfate (HS) are heteropolysaccharides implicated in the pathology of protein aggregation diseases including localized and systemic forms of amyloidosis. Among subdomains of sulfated GAGs, highly sulfated domains of HS, called HS S-domains, have been highlighted as being critical for HS function in amyloidoses. Recent studies suggest that the tumor suppressor p53 aggregates to form amyloid fibrils and propagates in a prion-like manner; however, molecules and mechanisms that are involved in the prion-like behavior of p53 aggregates have not been addressed.

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The left-handed, extended polyproline II (PPII) helix is a unique secondary structure which potently modulates peptide/protein functions through its constraint conformation. To investigate the effect of PPII helix on the direct cell membrane penetration of arginine-rich peptides, we designed a polyproline-containing arginine-rich peptide P9R7W (PPPPPPPPPRRRRRRRW) by introducing nine proline residues into a linear R7W (RRRRRRRW) peptide. Circular dichroism spectroscopy showed that P9R7W has the PPII helix structure in solution whereas R7W is predominantly in random coil structure.

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Glycosylation is one of the most important modifications of proteins and lipids, and cell surface glycoconjugates are thought to play important roles in a variety of biological functions including cell-cell and cell-substrate interactions, bacterial adhesion, cell immunogenicity and cell signaling. Alterations of glycosylation are observed in a number of inflammatory diseases. Pro-inflammatory cytokines have been shown to modulate cell surface glycosylation by regulating the expression of glycosyltransferases and sulfotransferases involved in the biosynthesis of glycan chains, inducing the expression of specific carbohydrate antigens at the cell surface that can be recognized by different types of lectins or by bacterial adhesins, contributing to the development of diseases.

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Chondroitin sulfate (CS) and heparan sulfate (HS) are glycosaminoglycans that both bind the receptor-type protein tyrosine phosphatase PTPRσ, affecting axonal regeneration. CS inhibits axonal growth, while HS promotes it. Here, we have prepared a library of HS octasaccharides and, together with synthetic CS oligomers, we found that PTPRσ preferentially interacts with CS-E-a rare sulfation pattern in natural CS-and most HS oligomers bearing sulfate and sulfamate groups.

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