Biology subjects

Nishizawa, C.

Publications and source records attributed to Nishizawa, C..

2 recordsLinked to original sources

bioRxiv2026

A bone fragment-based protocol for molecular analysis of osteocyte-associated transcripts in human bone specimens

Osteocytes play a central role in bone remodeling, mineral metabolism, and skeletal homeostasis, but direct molecular analysis of human osteocytes remains technically challenging because they are embedded within the mineralized bone matrix. Surgically obtained human bone specimens provide valuable material for studying human bone biology; however, surface-associated cells, marrow-derived cells, and adherent soft tissues can confound downstream transcript analysis. Here, we describe a bone fragment-based protocol for preparing surgically obtained human bone specimens for molecular analysis of osteocyte-associated transcripts. The protocol consists of mechanical trimming, mincing into small bone fragments, repeated washing, and five sequential rounds of collagenase digestion to reduce non-osteocytic cellular components associated with the bone surface and marrow spaces. The remaining mineralized bone fragments are then frozen in liquid nitrogen, cryogenically pulverized, and lysed in TRIzol reagent for total RNA extraction. Histological validation using residual maxillary bone specimens showed that sequential collagenase digestion markedly reduced adherent soft tissue and extra-matrix nuclei while preserving osteocyte lacunar occupancy. This protocol provides a practical workflow for bone fragment-based RNA analysis focused on osteocyte-associated transcripts in human bone specimens. Specifications table O_TBL View this table: org.highwire.dtl.DTLVardef@1cec618org.highwire.dtl.DTLVardef@2f746forg.highwire.dtl.DTLVardef@1854247org.highwire.dtl.DTLVardef@1c26c1aorg.highwire.dtl.DTLVardef@1473a88_HPS_FORMAT_FIGEXP M_TBL C_TBL

cell biology↗

bioRxiv2026

Radicular and periodontal structural defects underlie refractory oral pathology in the adult Hyp mouse model of X-linked hypophosphatemia

ObjectiveX-linked Hypophosphatemia is associated with dental complications, including spontaneous endodontic infections (abscesses) in non-carious teeth and severe periodontal loss. Previous studies have mainly focused on dentin Hypomineralization; however, the structural basis underlying periodontal tissue failure remains unclear. We aimed to investigate histoanatomical abnormalities in the dentin and periodontium of Hyp mice to clarify structural consequences of Phex deficiency in adult molars. MethodsWe performed detailed histological and scanning electron microscopy analyses on the molar regions of untreated adult Hyp mice and wild-type littermates, with particular attention to the structural integrity of the root and periodontal ligament. Additionally, odontoblast process morphology and periodontal attachment abnormalities were evaluated. ResultsHyp molars exhibited marked root abnormalities, including radicular shunt-like defects and disorganized odontoblast processes, particularly in furcation and radicular dentin. Periodontal attachment showed characteristic asymmetry: detachment from the cementum surface was frequently observed, whereas attachment to the alveolar bone surface was relatively preserved. These changes were accompanied by thinning and discontinuity of Sharpeys fibers and increased vascularity in the periodontal ligament. ConclusionsThese findings provide a histoanatomical framework for understanding refractory dental complications in X-linked hypophosphatemia and support the importance of intervention during root development.

pathology↗