Hiromi Hongo

Hokkaido University

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Histochemical characteristics on minimodeling-based bone formation induced by anabolic drugs for osteoporotic treatment

Biomedical Research (2021)

Tomomaya Yamamoto Tomoka Hasegawa Paulo Henrique Luiz de Fraitas Hiromi Hongo Shen Zhao

Modeling, the changes of bone size and shape, often takes place at the developmental stages, whereas bone remodeling-replacing old bone with new bone-predominantly occurs in adults. Unlike bone remodeling, bone formation induced by modeling i.e., minimodeling (microscopic modeling in cancellous bone) is independent of osteoclastic bone resorption. Although recently-developed drugs for osteoporotic treatment could induce minimodeling-based bone formation in addition to remodeling-based bone formation, few reports have demonstrated the histological aspects of minimodeling-based bone formation. After administration of eldecalcitol or romosozumab, unlike teriparatide treatment, mature osteoblasts formed new bone by minimodeling, without developing thick preosteoblastic layers. The histological characteristics of minimodeling-based bone formation is quite different from remodeling, as it is not related to osteoclastic bone resorption, resulting in convex-shaped new bone and smooth cement lines called arrest lines. In this review, we will show histological properties of minimodeling-based bone formation by osteoporotic drugs.

Bone remodeling

Bone remodeling period

Bone Formation

Cancellous bone

Teriparatide

Bone cell

10.2220/biomedres.42.161

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Citations (6)

<b>Immunolocalization of osteocyte-derived molecules during bone fracture healing of mouse </b><b>ribs </b>

Biomedical Research (2016)

Zhusheng Liu Tomomaya Yamamoto Tomoka Hasegawa Hiromi Hongo Kanako Tsuboi

We employed a well-standardized murine rib fracture model to assess the distribution, in the cortical bone, of three important osteocyte-derived molecules—dentine matrix protein 1 (DMP1), sclerostin and fibroblast growth factor 23 (FGF 23). Two days after the fracture, the periosteum thickened, and up to the seventh day post-fracture, the cortical surfaces were promoting neoformation of two tissue types depending on the distance from the fracture site: chondrogenesis was taking place near the fracture, and osteogenesis distant from it. The cortical bones supporting chondrogenesis featured several empty lacunae, while in the ones underlying newly-formed woven bone, empty lacunae were hardly seen. DMP1-immunopositive osteocytic lacunae and canaliculi were seen both close and away from the fracture. In contrast, the region close to the fracture had only few sclerostin- and FGF23-immunoreactive osteocytes, whereas the distant region revealed many osteocytes immunopositive for these markers. Mature cortical bone encompassing the native cortical bone was observed at two-, three- and four-weeks post-fracture, and the distribution of DMP1, sclerostin and FGF23 appeared to have returned to normal. In summary, early stages of fracture healing seem to be important for triggering chondrogenesis and osteogenesis that may be regulated by osteocytes via their secretory molecules.

Osteocyte

Sclerostin

Bone canaliculus

Chondrogenesis

DMP1

Periosteum

Bone fracture

10.2220/biomedres.37.141

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Citations (4)

Histochemical assessment of the femora of Spontaneously Diabetic Torii-Lepr (SDT-fa/fa) rats that mimic type II diabetes

Journal of Oral Biosciences (2024)

Qi Yao Kanako Tsuboi Hiromi Hongo Masayoshi Sakakibara Tomomaya Yamamoto

10.1016/j.job.2024.100602

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Histological assessment for femora of ovariectomized obesity (db/db) mice carrying mutated leptin receptor.

PubMed (2016)

Yosuke Tanaka Tomoka Hasegawa Tamaki Yamada Tomomaya Yamamoto Muneteru Sasaki

In order to provide a clue to understand the interplay between leptin and estrogen, we have examined femoral metaphyses of ovariectomized db/db mice carrying a mutated leptin receptor. We performed ovariectomy (OVX) or sham-operation (sham) on 12-week old female wild-type and db/db mice, and then, after 8 weeks, divided the animals into four groups: wild-type sham, wild-type OVX, db/db sham and db/db OVX. Samples from all groups were prepared for histochemical and ultrastructural examinations. As a result, db/db sham mice showed a reduced number and thickness of metaphyseal trabeculae and excessive adipose tissue when compared to wild-type sham mice. The wild-type OVX group exhibited markedly diminished trabecular number, as well as lower populations of osteoblasts and osteoclasts in comparison to wild-type sham group. On the other hand, trabecular numbers were similar for the two db/db groups, suggesting that the effect of the ovariectomy, i.e., estrogen deficiency may be lessened in this animal model. Leptin receptor was mainly found in osteoblasts and in bone marrow stromal cells including adipocytes. In addition, the expression of estrogen receptor did not seem to change after OVX in wild-type mice and in db/db mice. Both db/db sham and OVX mice featured many adipocytes close to the metaphyseal chondro-osseous junction, while osteoblasts accumulated glycogen granules and lipid droplets. Therefore, it seems likely that the disruption of leptin signaling in db/db mice shifts the cell differentiation cascade towards the adipocyte lineage, resulting in an osteoporotic bone independently of estrogen deficiency.

Leptin receptor

10.14670/hh-11-758

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Citations (2)

Influence of Ovariectomy followed by Progesterone Treatment on Development and Recovery Rate of Ova in Superovulated Adult Rats

Nihon Chikusan Gakkaiho (1982)

Jutaro Takahashi Hiromi Hongo Junji MASAKI

PMSG 50IUとHCG 50IUを併用して過排卵を誘起させたラットの交配後の受精率ならびに受精卵の発育に及ぼす卵巣摘出の影響について調べ,自然排卵によって妊娠した対照群のラットの成績と比較した.過排卵処理されたラットの排卵率は100%で平均排卵数は29.5±1.2個を示し,自然排卵数11.6±1.4個の約2.5倍であった.これらのラットは全例が雄と交配し,妊娠1日目の午前10時30分から12時における前核形成率は90.6%で,対照群の92.6%との間に有意差はみられなかった.過排卵処理群では,妊娠1,2および3日目に卵巣を摘出した後,プロジェステロンを投与された妊娠5日目のラット子宮からの潅流胚数は対照群にくらべて有意に多かった.胚の回収率は処理群では33.3～43.2%,対照群では26.2～41.5%でほとんど差はなかったが,両群の無手術の動物ではそれぞれ21.7%と66.7%を示し,過排卵処理群では卵巣摘出によって回収率が高まり,対照群では低くなった.潅流によって得られた胚の多くは胚盤胞へ発生していたが,処理群と対照群の無手術のラットでは,透明帯の消失率と胚盤胞の大きさに有意の差が認められた.また,過排卵処理された全ての動物の卵巣に胞状卵胞が認められた.これらの結果から,PMSGとHCGの併用によって過排卵処理されたラットの卵巣は,妊娠初期の生殖道内での胚の発生と生存に悪影響を与えていることが示唆さなた.

10.2508/chikusan.53.260

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Assessment of histological alterations in cartilage and extracellular matrix driven by collagen-induced arthritis in Macaca fascicularis

Arthritis Research & Therapy (2012)

Norio Amizuka Hiromi Hongo Muneteru Sasaki Tomoka Hasegawa Paulo Henrique Luiz de Freitas

Rheumatology has pioneered in the study of autoantibodies by showing that they are not only involved in pathogenesis but are also highly useful as diagnostic biomarkers.The diagnostic biomarker aspect of autoimmunity has gained increasing importance in cancer and many of the insights gained in Rheumatology have contributed to understanding the significance of autoantibodies in cancer.Features of autoantibodies in rheumatic disorders: In rheumatic diseases no individual autoantibody-antigen system has sufficient combination of sensitivity and specificity to serve as a useful diagnostic biomarker.Instead, several antigen-antibody systems constructed as profiles of biomarkers are highly effective in distinguishing one disorder from another.In lupus, anti-double strand DNA and anti-Sm distinguishes it from scleroderma, where the profile is anti-DNA topoisomerase 1 and anti-centromere proteins.The autoantigensare cell components involved in universal and basic gene expression pathways, such as Sm in precursor mRNA splicing and DNA topoisomerase 1 in DNA replication and transcription [1].Features of autoantibodies in cancer: Autoantibodies in cancer target intracellular molecules referred to as TAAs (tumor-associated antigens).As in rheumatic disorders, no individual autoantibody-antigen system has sensitivity and specificity to serve as a stand-alone diagnostic marker [2].Most tumors show multiple antibody specificities and with panels of TAAanti-TAAs (analogous toprofiles) the cumulative sensitivity and specificity reaches diagnostic significance.Different tumorigenesis pathways are

Collagen-induced arthritis

Bone matrix

10.1186/ar3569

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Citations (1)

Morphological aspects of the biological function of the osteocytic lacunar canalicular system and of osteocyte‐derived factors

Oral Science International (2012)

Muneteru Sasakia Hiromi Hongo Tomoka Hasegawa Reiko Suzuki Zhusheng Liu

Abstract Osteocytes are organized in functional syncytia collectively referred to as the osteocytic lacunar‐canalicular system (OLCS). The osteocytes are interconnected through gap junctions between their cytoplasmic processes, which pass through narrow passageways referred to as osteocytic canaliculi. There are two possible ways molecules can be transported throughout the OLCS: via the cytoplasmic processes and their gap junctions, and via the pericellular space in the osteocytic canaliculi. Transport of minerals and small molecules through a spatially well‐organized OLCS is vital for bone mineral homeostasis, mechanosensing, and bone remodeling control. Recently, osteocyte‐derived molecules – sclerostin, dentin matrix protein‐1, fibroblast growth factor 23 (FGF23) – have been put in evidence as they may be related to osteocytic functions such as mechanosensing, regulation of bone remodeling, and so forth. FGF23 regulates serum phosphate concentration by affecting renal function, while sclerostin can inhibit osteoblastic activities. In our observations, FGF23 and sclerostin synthesis seemed to be associated with the spatial regularity of the OLCS. This review will introduce our recent morphological studies on the regularity of OLCS and the synthesis of osteocyte‐derived FGF23 and sclerostin.

Osteocyte

Sclerostin

Bone canaliculus

Bone remodeling

10.1016/s1348-8643(12)00009-2

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Citations (24)

マウス歯胚の象牙芽細胞層におけるポドプラニン/E11/gp38,CD44,およびエンドムチンの免疫局在性

Khadiza Naznin Tomoka Hasegawa Tomoya Nagai Yamamoto Tomomaya Miyamoto Takasaki Yukina

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