IFT20 is required for the maintenance of cartilaginous matrix in condylar cartilage

AbstractIntermittent hypoxia (IH) has been associated with skeletal growth. However, the influence of IH on cartilage growth and metabolism is unknown. We compared the effects of IH on chondrocyte proliferation and maturation in the mandibular condyle fibrocartilage and tibial hyaline cartilage of 1-week-old male Sprague–Dawley rats. The rats were exposed to normoxic air (n = 9) or IH at 20 cycles/h (nadir, 4% O2; peak, 21% O2; 0% CO2) (n = 9) for 8 h each day. IH impeded body weight gain, but not tibial elongation. IH also increased cancellous bone mineral and volumetric bone mineral densities in the mandibular condylar head. The mandibular condylar became thinner, but the tibial cartilage did not. IH reduced maturative and increased hypertrophic chondrocytic layers of the middle and posterior mandibular cartilage. PCR showed that IH shifted proliferation and maturation in mandibular condyle fibrocartilage toward hypertrophic differentiation and ossification by downregulating TGF-β and SOX9, and upregulating collagen X. These effects were absent in the tibial growth plate hyaline cartilage. Our results showed that neonatal rats exposed to IH displayed underdeveloped mandibular ramus/condyles, while suppression of chondrogenesis marker expression was detected in the growth-restricted condylar cartilage.

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Overloading stress–induced progressive degeneration and self‐repair in condylar cartilage

Annals of the New York Academy of Sciences ◽

10.1111/nyas.14606 ◽

2021 ◽

Author(s):

Lingli Fang ◽

Yusi Ye ◽

Xi Tan ◽

Lan Huang ◽

Yao He

Keyword(s):

Condylar Cartilage ◽

Progressive Degeneration ◽

Self Repair

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A histochemical study on condylar cartilage and glenoid fossa during mandibular advancement

The Angle Orthodontist ◽

10.2319/021710-99.1 ◽

2011 ◽

Vol 81 (2) ◽

pp. 270-276 ◽

Cited By ~ 11

Author(s):

Payam Owtad ◽

Zoe Potres ◽

Gang Shen ◽

Peter Petocz ◽

M. Ali Darendeliler

Keyword(s):

Histochemical Study ◽

Mandibular Advancement ◽

Glenoid Fossa ◽

Condylar Cartilage

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The Effects of Tgfb1 and Csf3 on Chondrogenic Differentiation of iPS Cells in 2D and 3D Culture Environment

International Journal of Molecular Sciences ◽

10.3390/ijms22062978 ◽

2021 ◽

Vol 22 (6) ◽

pp. 2978

Author(s):

Chie-Hong Wang ◽

Chun-Hao Tsai ◽

Tsung-Li Lin ◽

Shih-Ping Liu

Keyword(s):

Cell Proliferation ◽

Chondrogenic Differentiation ◽

Expression Profiles ◽

Es Cells ◽

3D Culture ◽

Ips Cells ◽

3D Cultures ◽

Positive Effects ◽

Cartilaginous Matrix ◽

Culture Environment

Mesenchymal stem (MS) cells, embryonic stem (ES) cells, and induced pluripotent stem (iPS) cells are known for their ability to differentiate into different lineages, including chondrocytes in culture. However, the existing protocol for chondrocyte differentiation is time consuming and labor intensive. To improve and simplify the differentiation strategy, we have explored the effects of interactions between growth factors (transforming growth factor β1 (Tgfb1) and colony stimulating factor 3 (Csf3), and culture environments (2D monolayer and 3D nanofiber scaffold) on chondrogenic differentiation. For this, we have examined cell morphologies, proliferation rates, viability, and gene expression profiles, and characterized the cartilaginous matrix formed in the chondrogenic cultures under different treatment regimens. Our data show that 3D cultures support higher proliferation rate than the 2D cultures. Tgfb1 promotes cell proliferation and viability in both types of culture, whereas Csf3 shows positive effects only in 3D cultures. Interestingly, our results indicate that the combined treatments of Tgfb1 and Csf3 do not affect cell proliferation and viability. The expression of cartilaginous matrix in different treatment groups indicates the presence of chondrocytes. We found that, at the end of differentiation stage 1, pluripotent markers were downregulated, while the mesodermal marker was upregulated. However, the expression of chondrogenic markers (col2a1 and aggrecan) was upregulated only in the 3D cultures. Here, we report an efficient, scalable, and convenient protocol for chondrogenic differentiation of iPS cells, and our data suggest that a 3D culture environment, combined with tgfb1 and csf3 treatment, promotes the chondrogenic differentiation.

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Parathyroid hormone promotes cartilage healing after free reduction of mandibular condylar fractures by upregulating Sox9

Experimental Biology and Medicine ◽

10.1177/15353702211027114 ◽

2021 ◽

pp. 153537022110271

Author(s):

Yuanyuan Jia ◽

Liuqin Xie ◽

Zhenglong Tang ◽

Dongxiang Wang ◽

Yun Hu ◽

...

Keyword(s):

Parathyroid Hormone ◽

Internal Fixation ◽

Early Stage ◽

Rabbit Model ◽

Mandibular Condyle ◽

Fracture Site ◽

Control Group ◽

Condylar Cartilage ◽

Cartilage Healing ◽

Experimental Group

After high fractures of the mandibular condyle, the insufficient blood supply to the condyle often leads to poor bone and cartilage repair ability and poor clinical outcome. Parathyroid hormone (PTH) can promote the bone formation and mineralization of mandibular fracture, but its effects on cartilage healing after the free reduction and internal fixation of high fractures of the mandibular condyle are unknown. In this study, a rabbit model of free reduction and internal fixation of high fractures of the mandibular condyle was established, and the effects and mechanisms of PTH on condylar cartilage healing were explored. Forty-eight specific-pathogen-free (SPF) grade rabbits were randomly divided into two groups. In the experimental group, PTH was injected subcutaneously at 20 µg/kg (PTH (1–34)) every other day, and in the control group, PTH was replaced with 1 ml saline. The healing cartilages were assessed at postoperative days 7, 14, 21, and 28. Observation of gross specimens, hematoxylin eosin staining and Safranin O/fast green staining found that every-other-day subcutaneous injection of PTH at 20 µg/kg promoted healing of condylar cartilage and subchondral osteogenesis in the fracture site. Immunohistochemistry and polymerase chain reaction showed that PTH significantly upregulated the chondrogenic genes Sox9 and Col2a1 in the cartilage fracture site within 7–21 postoperative days in the experimental group than those in the control group, while it downregulated the cartilage inflammation gene matrix metalloproteinase-13 and chondrocyte terminal differentiation gene ColX. In summary, exogenous PTH can stimulate the formation of cartilage matrix by triggering Sox9 expression at the early stage of cartilage healing, and it provides a potential therapeutic protocol for high fractures of the mandibular condyle.

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