Differences in the transport systems between cementocytes and osteocytes in rats using microperoxidase as a tracer

Ayasaka, Norio; Kondo, Teruyoshi; Goto, Tetsuya; Kido, Mizuho A.; Nagata, Emi; Takano, Teruo

doi:10.1016/0003-9969(92)90019-5

Cited by 36 publications

(35 citation statements)

References 9 publications

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“…Cementum is a specialized calcified tissue that covers tooth roots [13][14][15] and can be classified into the following two types: acellular cementum that contains no cell components and is restricted to the coronal half of the root, and cellular cementum that contains cementocytes in lacunae and is localized to the apical half of the root. 13 Cementocytes have numerous cell processes throughout the canaliculi that are used to communicate with neighboring cementocytes and cells lining the cementum surface, which are similar to those of osteocytes.…”

Section: Introductionmentioning

confidence: 99%

“…13 Cementocytes have numerous cell processes throughout the canaliculi that are used to communicate with neighboring cementocytes and cells lining the cementum surface, which are similar to those of osteocytes. 13,14 In addition, cementocytes share their matrix proteins with osteocytes, such as type I collagen, osteopontin, and osteocalcin. 15 Considering these similarities, we hypothesized that similar apoptotic changes might occur in cementocytes during hyalinization on the pressure side of the PDL.…”

Section: Introductionmentioning

confidence: 99%

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Cementocyte cell death occurs in rat cellular cementum during orthodontic tooth movement

Matsuzawa

Toriya

Nakao

et al. 2016

The Angle Orthodontist

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Objective: To clarify the mechanism of root resorption during orthodontic treatment, we examined cementocyte cell death and root resorption in the cellular cementum on the pressure side during experimental tooth movement. Materials and Methods: Using 8-week-old male Wistar rats, the right first molar was pushed mesiobuccally with a force of 40 g by a Ni-Ti alloy wire while the contralateral first molar was used as a control. Localization and number of cleaved caspase-3-positive and single-stranded DNA (ssDNA) -positive cells were evaluated using dual-label immunohistochemistry with anticleaved caspase-3 and anti-ssDNA antibodies. In addition, tartrate-resistant acid phosphatase (TRAP)-positive cells in the cellular cementum were evaluated using TRAP histochemical staining. Results: Caspase-3-and ssDNA-positive cells appeared at 12 hours, but were restricted to the compressed periodontal ligament (PDL) and not the cellular cementum. Cleaved caspase-3-positive cementocytes were observed in the cellular cementum adjacent to the compressed PDL on day 1. From days 2 to 4, the number of caspase-3-and ssDNA-positive cementocytes increased. TRAP-positive cells appeared on the cellular cementum at the periphery of the hyalinized tissue on day 7, and resorption progressed into the broad surface of the cementum by day 14. Conclusion: Cementocytes adjacent to the hyalinized tissue underwent apoptotic cell death during orthodontic tooth movement, which might have been associated with subsequent root resorption. (Angle Orthod. 2017;87:416-422)

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cementocyte cell death occurs in rat cellular cementum during orthodontic tooth movement

Matsuzawa

Toriya

Nakao

et al. 2016

The Angle Orthodontist

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“…Osteocytes, the most numerous cells in adult bone, lie buried within the mineralized matrix and do not directly contact the tissue's vascular supply; consequently, they depend on solute transport through the tissue to obtain nutrients, dispose of metabolic wastes (1)(2)(3)(4), and transmit chemical signals (e.g., nitric oxide and prostaglandins) to nearby cells (5,6). These transport processes are thought to be crucial for osteocytes to carry out their physiological functions in sensing mechanical stimuli and targeting damaged bone areas for osteoclastic resorption (5,(7)(8)(9)(10).…”

mentioning

confidence: 99%

“…These transport processes are thought to be crucial for osteocytes to carry out their physiological functions in sensing mechanical stimuli and targeting damaged bone areas for osteoclastic resorption (5,(7)(8)(9)(10). Because the mineralized matrix of adult bone is largely impermeable to solutes (3,4), transport in bone occurs mainly via the extracellular spaces immediately surrounding osteocytes (termed lacunae) and their interconnecting processes (canaliculi). Typical diameters of lacunae and canaliculi are Ϸ10-20 and 0.5 m, respectively (1,11,12).…”

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confidence: 99%

In situ measurement of solute transport in the bone lacunar-canalicular system

Wang

Han

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

184

212

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Solute transport through the bone lacunar-canalicular system is believed to be essential for osteocyte survival and function but has proved difficult to measure. We report an approach that permits direct measurement of real-time solute movement in intact bones. By using fluorescence recovery after photobleaching, the movement of a vitally injected fluorescent dye (sodium fluorescein) among individual osteocytic lacunae was visualized in situ beneath the periosteal surface of mouse cortical bone at depths up to 50 m with laser scanning confocal microscopy. Transport was analyzed by using a two-compartment mathematical model of solute diffusion that accounted for the characteristic anatomical features of the lacunar-canalicular system. The diffusion coefficient of fluorescein (376 Da) was determined to be 3.3 ؎ 0.6 ؋ 10 ؊6 cm 2 ͞sec, which is 62% of its diffusion coefficient in water and is similar to diffusion coefficients measured for comparably sized molecules in cartilage. The diffusion of fluorescein in bone is also consistent with the presence of an osteocyte pericellular matrix whose structure resembles that proposed for the endothelial glycocalyx diffusion coefficient ͉ fiber matrix theory ͉ fluorescence recovery after photobleaching ͉ osteocyte ͉ confocal microscopy

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“…Bone interstitial fluid flow is also believed to aid in delivering nutrients and transporting metabolic waste products from the bone cells [17]. To better understand interstitial fluid movement in bone, techniques using markers or tracers such as procion red (300-400 Da, diameter <1 nm), reactive red (1470 Da, diameter ~1 nm), microperoxidase (1860 Da, diameter ~2 nm), horseradish peroxidase (40 kDa, diameter ~6 nm), ferritin (440 kDa, diameter ~12 nm [20]), and different-sized dextrans (range 300 Da-2000 kDa, diameter ~1 nm-60 nm) have been used to map how different sized molecules travel through the various porosities in bone [1,5,8,[13][14][15][16]19,[22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Mapping bone interstitial fluid movement: Displacement of ferritin tracer during histological processing

Ciani¹,

Doty²,

Fritton³

2005

Bone

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Bone interstitial fluid flow is thought to play a fundamental role in the mechanical stimulation of bone cells, either via shear stresses or cytoskeletal deformations. Recent evidence indicates that osteocytes are surrounded by a fiber matrix that may be involved in the mechanotransduction of external stimuli as well as in nutrient exchange. In our previous tracer studies designed to map how different-sized molecules travel through the bone porosities, we found that injected ferritin was confined to blood vessels and did not pass into the mineralized matrix. However, other investigators have shown that ferritin forms halo-shaped labeling that enters the mineralized matrix around blood vessels. This labeling is widely used to explain normal interstitial fluid movement in bone; in particular, it is said to demonstrate bulk centrifugal interstitial fluid movement away from a highly pressurized vascular porosity. In addition, appositional ferritin fronts are said to demonstrate centrifugal interstitial fluid movement from the medullary canal to the periosteal surface. The purpose of this study was to investigate the conflicting ferritin labeling results by evaluating the role of different histological processes in the formation of ferritin "halos." Ferritin was injected into the rat vasculature and allowed to circulate for 5 min. Samples obtained from tibiae were reacted for different times with Perl's reagent and then were either paraffin-embedded or sectioned with a cryostat. Halo-like labeling surrounding vascular pores was found in all groups, ranging from 1.2-3.9% for the samples treated with the shortest histological processes (unembedded, frozen sections) to 5.6-15% for the samples treated with the longest histological processes (paraffin-embedded sections). These results indicate that different histological processing methods are able to create ferritin "halos," with some processing methods allowing more redistribution of the ferritin tracer than others. Based on these results and the fact that "halo" labeling has not been found with any other tracer, as we seek to further delineate the movement of interstitial fluid and the role it plays in bone mechanotransduction, we believe that ferritin "halo" labeling should not be used to demonstrate physiological bone interstitial fluid flow.

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Differences in the transport systems between cementocytes and osteocytes in rats using microperoxidase as a tracer

Cited by 36 publications

References 9 publications

Cementocyte cell death occurs in rat cellular cementum during orthodontic tooth movement

Cementocyte cell death occurs in rat cellular cementum during orthodontic tooth movement

In situ measurement of solute transport in the bone lacunar-canalicular system

Mapping bone interstitial fluid movement: Displacement of ferritin tracer during histological processing

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