Biology subjects

Kitagawa, H.

Publications and source records attributed to Kitagawa, H..

4 recordsLinked to original sources

bioRxiv2025

Arylsulfatase I is a novel lysosomal chondroitin sulfatase regulating endochondral ossification

During endochondral ossification, chondrocytes undergo maturation and biochemically modify the collagenous extracellular matrix of cartilage. Similar modifications to cartilage proteoglycans (PGs), which are predominantly chondroitin sulfate, have not been characterized. Using synchrotron X-ray fluorescence imaging, we demonstrated that PG sulfation significantly decreased during cartilage maturation of chick embryos. Laser-capture microdissection and RNAseq revealed upregulation of Arylsulfatase I (Arsi) in mature cartilage of mouse. ARSI protein also increased in mature cartilage of mouse and chick in vivo and during maturation of ATDC5 chondrocytes in vitro, whereas expression of the two known chondroitin sulfate PG sulfatases (ARSB and GALNS) was not specific to mature cartilage. Colocalization studies suggested that ARSI is lysosomal, and functional assays revealed that ARSI impacts lysosome homeostasis in chondrocytes. Biochemical analyses of ARSI gain and loss of function cell lines and isolated cell-free systems revealed that ARSI is a novel chondroitin sulfatase, specifically desulfating GalNAc4S at the nonreducing terminal of CS/DS. Finally, Arsi knockout in RCS chondrocytes caused increased expression of maturation genes, such as Col10a1 and Mmp13. In total, these data identify ARSI as a novel PG sulfatase regulating endochondral ossification.

cell biology↗

bioRxiv2022

Assembly of neuron- and radial glial cell-derived extracellular matrix molecules promotes radial migration of developing cortical neurons

Radial neuronal migration is a key neurodevelopmental event for proper cortical laminar organization. The multipolar-to-bipolar transition, a critical step in establishing neuronal polarity during radial migration, occurs in the subplate/intermediate zone (SP/IZ), a distinct region of the embryonic cerebral cortex. It has been known that the extracellular matrix (ECM) molecules are enriched in the SP/IZ. However, the molecular constitution and functions of the ECM formed in this region remain poorly understood. Here, we identified neurocan (NCAN) as a major chondroitin sulfate proteoglycan in the SP/IZ. NCAN binds to both radial glial cell-derived tenascin-C (TNC) and hyaluronan (HA), a large linear polysaccharide, forming a ternary complex of NCAN, TNC, and HA in the SP/IZ. Developing cortical neurons make contact with the ternary complex during migration. The enzymatic or genetic disruption of the ternary complex impairs radial migration by suppressing the multipolar-to-bipolar transition. Furthermore, both TNC and NCAN promoted the morphological maturation of cortical neurons in vitro. The present results provide evidence for the cooperative role of neuron- and radial glial cell-derived ECM molecules in cortical development.

neuroscience↗

bioRxiv2020

Overlapping and non-overlapping roles of the class-I histone deacetylase-1 corepressors, LET-418, SIN-3, and SPR-1 in Caenorhabditis elegans embryonic development

Histone deacetylases (HDACs) are divided into four classes. Class-I HDAC, HDAC-1 forms three types of complexes, namely the Nucleosome Remodeling Deacetylase complex, the Sin3 complex, and the CoREST complex, with specific corepressor component Mi2/CHD-3, Sin3, and RCOR1 in human, respectively. The functions of these HDAC-1 complexes are regulated by their corepressors, however, their exact mechanistic roles in several biological processes remain unexplored, such as in embryonic development. Here, we report that each of the corepressors, LET-418, SIN-3, and SPR-1, the homologous of Mi2, Sin3, and RCOR1, respectively, were expressed throughout Caenorhabditis elegans embryonic development and served essential roles in the process. Moreover, genetic analysis suggested that three pathways (i.e., LET-418- SIN-3-SPR-1, SIN-3-SPR-1, and LET-418) participated in embryonic development. Our terminal-phenotype observations of single mutants of each corepressor implied that LET-418, SIN-3, and SPR-1 played similar roles in promoting advancement to the middle and late embryonic stages. Genome-wide comparative-transcriptome analysis indicated that 47.5% and 42.3% of genes were commonly increased and decreased in sin-3 and spr-1 mutants, respectively. These results suggest that among the three pathways studied, the SIN-3-SPR-1 pathway mainly serves to regulate embryonic development. Comparative-Gene Ontology analysis indicated that these three pathways played overlapping and distinct roles in regulating C. elegans embryonic development.

developmental biology↗

bioRxiv2020

Restoring the pattern of perineuronal net sulphation corrects age-related memory loss

Memory loss is a usual consequence of ageing and aged mice show progressive deficits in memory tasks. In aged brains, perineuronal nets (PNNs), which are implicated in plasticity and memory, become inhibitory due to decreased 6-sulphation of their glycan chains (C6S). Removal of PNNs or digestion of their glycosaminoglycans rescued age-related memory loss. Premature reduction of permissive C6S by transgenic deletion of chondroitin 6-sulfotransferase led to very early memory loss. However, restoring C6S levels in aged animals by AAV delivery or transgenic expression of 6-sulfotransferase restored memory. Low C6S levels caused loss of cortical long-term potentiation, which was restored by AAV-mediated 6-sulfotransferase delivery. The study shows that loss of C6S in the aged brain leads to declining memory and cognition. Age-related memory impairment was restored by C6S replacement or other interventions targeting perineuronal nets

neuroscience↗