Abstract:Background: Differences in the development of fibrocartilage layers in quadriceps tendon (QT) and patellar tendon (PT) insertion sites are unclear. Because the mechanical environments for the QT and PT are different, the development of the QT and PT insertions may differ. Purpose: To investigate differences in the development of fibrocartilage layers in the QT and PT insertion sites in rabbits through use of quantitative morphometric evaluations. Study Design: Descriptive laboratory study. Methods: This study … Show more
“…The collected specimens were sliced into sagittal sections of 5 µm thickness at the center of AT enthesis. The slices were stained with hematoxylin and eosin (H&E) and safranin O to assess the histomorphological characteristics and GAG content 3 , 4 , 7 , 8 , 9 , 10 ) . We also performed the proliferating cell nuclear antigen (PCNA) staining to detect the proliferating cells ( Figure 1a Figure 1 Immunohistochemical staining.…”
Section: Methodsmentioning
confidence: 99%
“…PCNA, proliferating cell nuclear antigen; TUNEL: terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling; Sox9: sex-determining region Y box 9. ) 3 , 4 , 7 , 8 , 9 , 10 ) , terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) staining to detect the apoptotic cells ( Figure 1b ) 3 , 4 , 7 , 8 , 9 , 10 ) , and Sox9 staining to evaluate the developmental differentiation of chondrocytes ( Figure 1c ) 3 , 4 ) . For PCNA staining, the Histofine ® SAB-PO (M) kit (Nichirei Biosciences, Inc., Tokyo, Japan) was used according to the manufacturer’s instructions 3 , 4 , 7 , 8 , 9 , 10 ) .…”
Section: Methodsmentioning
confidence: 99%
“…S0809; Dako) have also been used 3 , 4 , 7 , 8 , 9 , 10 ) . For TUNEL staining, the Apoptag ® Plus Peroxidase In Situ Apoptosis Detection Kit (Merck Millipore, Billerica, MA, USA) was used following the manufacturer’s instructions 3 , 4 , 7 , 8 , 9 , 10 ) . For Sox9 staining, the Histofine ® SAB-PO (R) Kit (Nichirei Biosciences, Inc.) and Rabbit-To-Rabbit blocking reagent (ScyTek Laboratories, Inc., Logan, UT, USA) were used according to the manufacturer’s instructions 3 , 4 ) .…”
Section: Methodsmentioning
confidence: 99%
“…To examine the development of fibrocartilage layers during ACL, QT, and PT insertions, quantitative morphometric evaluations have been performed in rabbits 3 , 4 ) . During the development of fibrocartilage layers during tibial ACL insertion in rabbits, chondrocyte proliferation and sex-determining region Y box 9 (Sox9) expression increases until 12 weeks of age, along with GAG production, which is in accordance with the increase in ACL length and its insertion width 3 ) .…”
Section: Introductionmentioning
confidence: 99%
“…The development of fibrocartilage layers during ACL insertion is completed by 12 weeks of age 3 ) . In rabbits, the development of fibrocartilage layers during QT and PT insertions is also completed by 12 weeks of age 4 ) . However, the developmental processes of fibrocartilage layers during QT and PT insertions differ substantially in rabbits 4 ) .…”
Objective:
The details regarding the development of fibrocartilage layers in
Achilles tendon (AT) enthesis are unknown. Therefore, we evaluated the development of
fibrocartilage layers in AT enthesis using a rabbit model.
Materials and Methods:
Forty-eight male Japanese white rabbits were used in
this study. Six of them were euthanized at different stages (day 1, and 1, 2, 4, 6, 8, 12,
and 24 weeks of age). The proliferation, apoptosis, Sox9-positivity rates, and chondrocyte
number were evaluated. Additionally, safranin O-stained glycosaminoglycan (GAG) areas,
width of AT enthesis, and calcaneus length were assessed. All parameters were compared to
those at 24 weeks of age.
Results:
The level of chondrocyte apoptosis was high from 1 to 8 weeks of
age, and high expression level of Sox9 was maintained from day 1 to 6 weeks of age, which
decreased gradually. Safranin O-stained GAG areas increased up to 12 weeks, calcaneus
length increased up to 6 weeks, and the width of AT enthesis increased up to 1 week of
age.
Conclusion:
The changes in chondrocyte and extracellular matrix were
completed by 8 and 12 weeks of age, respectively. The development of fibrocartilage layers
in AT enthesis was completed by 12 weeks of age. Our results contribute to the
administration of appropriate treatments based on age and aid in the development of novel
methods for regenerating AT enthesis.
“…The collected specimens were sliced into sagittal sections of 5 µm thickness at the center of AT enthesis. The slices were stained with hematoxylin and eosin (H&E) and safranin O to assess the histomorphological characteristics and GAG content 3 , 4 , 7 , 8 , 9 , 10 ) . We also performed the proliferating cell nuclear antigen (PCNA) staining to detect the proliferating cells ( Figure 1a Figure 1 Immunohistochemical staining.…”
Section: Methodsmentioning
confidence: 99%
“…PCNA, proliferating cell nuclear antigen; TUNEL: terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling; Sox9: sex-determining region Y box 9. ) 3 , 4 , 7 , 8 , 9 , 10 ) , terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) staining to detect the apoptotic cells ( Figure 1b ) 3 , 4 , 7 , 8 , 9 , 10 ) , and Sox9 staining to evaluate the developmental differentiation of chondrocytes ( Figure 1c ) 3 , 4 ) . For PCNA staining, the Histofine ® SAB-PO (M) kit (Nichirei Biosciences, Inc., Tokyo, Japan) was used according to the manufacturer’s instructions 3 , 4 , 7 , 8 , 9 , 10 ) .…”
Section: Methodsmentioning
confidence: 99%
“…S0809; Dako) have also been used 3 , 4 , 7 , 8 , 9 , 10 ) . For TUNEL staining, the Apoptag ® Plus Peroxidase In Situ Apoptosis Detection Kit (Merck Millipore, Billerica, MA, USA) was used following the manufacturer’s instructions 3 , 4 , 7 , 8 , 9 , 10 ) . For Sox9 staining, the Histofine ® SAB-PO (R) Kit (Nichirei Biosciences, Inc.) and Rabbit-To-Rabbit blocking reagent (ScyTek Laboratories, Inc., Logan, UT, USA) were used according to the manufacturer’s instructions 3 , 4 ) .…”
Section: Methodsmentioning
confidence: 99%
“…To examine the development of fibrocartilage layers during ACL, QT, and PT insertions, quantitative morphometric evaluations have been performed in rabbits 3 , 4 ) . During the development of fibrocartilage layers during tibial ACL insertion in rabbits, chondrocyte proliferation and sex-determining region Y box 9 (Sox9) expression increases until 12 weeks of age, along with GAG production, which is in accordance with the increase in ACL length and its insertion width 3 ) .…”
Section: Introductionmentioning
confidence: 99%
“…The development of fibrocartilage layers during ACL insertion is completed by 12 weeks of age 3 ) . In rabbits, the development of fibrocartilage layers during QT and PT insertions is also completed by 12 weeks of age 4 ) . However, the developmental processes of fibrocartilage layers during QT and PT insertions differ substantially in rabbits 4 ) .…”
Objective:
The details regarding the development of fibrocartilage layers in
Achilles tendon (AT) enthesis are unknown. Therefore, we evaluated the development of
fibrocartilage layers in AT enthesis using a rabbit model.
Materials and Methods:
Forty-eight male Japanese white rabbits were used in
this study. Six of them were euthanized at different stages (day 1, and 1, 2, 4, 6, 8, 12,
and 24 weeks of age). The proliferation, apoptosis, Sox9-positivity rates, and chondrocyte
number were evaluated. Additionally, safranin O-stained glycosaminoglycan (GAG) areas,
width of AT enthesis, and calcaneus length were assessed. All parameters were compared to
those at 24 weeks of age.
Results:
The level of chondrocyte apoptosis was high from 1 to 8 weeks of
age, and high expression level of Sox9 was maintained from day 1 to 6 weeks of age, which
decreased gradually. Safranin O-stained GAG areas increased up to 12 weeks, calcaneus
length increased up to 6 weeks, and the width of AT enthesis increased up to 1 week of
age.
Conclusion:
The changes in chondrocyte and extracellular matrix were
completed by 8 and 12 weeks of age, respectively. The development of fibrocartilage layers
in AT enthesis was completed by 12 weeks of age. Our results contribute to the
administration of appropriate treatments based on age and aid in the development of novel
methods for regenerating AT enthesis.
Background and Objectives: The influence of periostin on the growth of the patella tendon (PT) tibial insertion is unknown. The research described here aimed to reveal the contribution of periostin to the growth of fibrocartilage layers of the PT tibial insertion using periostin knockout mice. Materials and Methods: In both the wild-type (WD; C57BL/6N, periostin +/+; n = 54) and periostin knockout (KO; periostin −/−; n = 54) groups, six mice were euthanized on day 1 and at 1, 2, 3, 4, 6, 8, 10, and 12 weeks of age. Chondrocyte proliferation and apoptosis, number of chondrocytes, safranin O-stained glycosaminoglycan (GAG) area, staining area of type II collagen, and length of the tidemark were investigated. Results: Chondrocyte proliferation and apoptosis in KO were lower than those in WD on day 1 and at 1, 4, and 8 weeks and on day 1 and at 4, 6, and 12 weeks, respectively. Although the number of chondrocytes in both groups gradually decreased, it was lower in KO than in WD on day 1 and at 8 and 12 weeks. In the extracellular matrix, the GAG-stained area in KO was smaller than that in WD on day 1 and at 1, 4, 8, 10, and 12 weeks. The staining area of type II collagen in KO was smaller than that in WD at 8 weeks. The length of the tidemark in KO was shorter than that in WD at 4 and 6 weeks. Conclusion: Loss of periostin led to decreased chondrocyte proliferation, chondrocyte apoptosis, and the number of chondrocytes in the growth process of the PT tibial insertion. Moreover, periostin decreased and delayed GAG and type II collagen production and delayed tidemark formation in the growth process of the PT tibial insertion. Periostin can, therefore, contribute to the growth of fibrocartilage layers in the PT tibial insertion. Periostin deficiency may result in incomplete growth of the PT tibial insertion.
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