Prolactin inhibits the apoptosis of chondrocytes induced by serum starvation

The apoptosis of chondrocytes plays an important role in endochondral bone formation and in cartilage degradation during aging and disease. Prolactin (PRL) is produced in chondrocytes and is known to promote the survival of various cell types. Here we show that articular chondrocytes from rat postpubescent and adult cartilage express the long form of the PRL receptor as revealed by immunohistochemistry of cartilage sections and by RT-PCR and Western blot analyses of the isolated chondrocytes. Furthermore, we demonstrate that PRL inhibits the apoptosis of these same chondrocytes cultured in low-serum. Chondrocyte apoptosis was measured by hypodiploid DNA content determined by flow cytometry and by DNA fragmentation evaluated by the ELISA and the TUNEL methods. The anti-apoptotic effect of PRL was dose-dependent and was prevented by heat inactivation. These data demonstrate that PRL can act as a survival factor for chondrocytes and that it has potential preventive and therapeutic value in arthropathies characterized by cartilage degradation.

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Chondrocytes Play a Major Role in the Stimulation of Bone Growth by Thyroid Hormone

Endocrinology ◽

10.1210/en.2014-1109 ◽

2014 ◽

Vol 155 (8) ◽

pp. 3123-3135 ◽

Cited By ~ 25

Author(s):

Clémence Desjardin ◽

Cyril Charles ◽

Catherine Benoist-Lasselin ◽

Julie Riviere ◽

Mailys Gilles ◽

...

Keyword(s):

Thyroid Hormone ◽

Bone Growth ◽

Cell Types ◽

Postnatal Growth ◽

Dominant Negative ◽

Skeletal Growth ◽

Endochondral Bone Formation ◽

Endochondral Bone ◽

Phenotype Analysis ◽

Visible Effect

Thyroid hormone (T3) is required for postnatal skeletal growth. It exerts its effect by binding to nuclear receptors, TRs including TRα1 and TRβ1, which are present in most cell types. These cell types include chondrocytes and osteoblasts, the interactions of which are known to regulate endochondral bone formation. In order to analyze the respective functions of T3 stimulation in chondrocytes and osteoblasts during postnatal growth, we use Cre/loxP recombination to express a dominant-negative TRα1L400R mutant receptor in a cell-specific manner. Phenotype analysis revealed that inhibiting T3 response in chondrocytes is sufficient to reproduce the defects observed in hypothyroid mice, not only for cartilage maturation, but also for ossification and mineralization. TRα1L400R in chondrocytes also results in skull deformation. In the meantime, TRα1L400R expression in mature osteoblasts has no visible effect. Transcriptome analysis identifies a number of changes in gene expression induced by TRα1L400R in cartilage. These changes suggest that T3 normally cross talks with several other signaling pathways to promote chondrocytes proliferation, differentiation, and skeletal growth.

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P175 Administration of TGF beta-1 during the expansion of human articular chondrocytes may trigger the ontogenesis of endochondral bone formation in the cultured cells

Osteoarthritis and Cartilage ◽

10.1016/s1063-4584(07)61530-1 ◽

2007 ◽

Vol 15 ◽

pp. B132

Author(s):

R. Narcisi ◽

P. Giannoni ◽

R. Arbico ◽

A. Muraglia ◽

V. Ulivi ◽

...

Keyword(s):

Bone Formation ◽

Cultured Cells ◽

Articular Chondrocytes ◽

Human Articular Chondrocytes ◽

Endochondral Bone Formation ◽

Tgf Beta ◽

Endochondral Bone

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Site-1 protease is essential for endochondral bone formation in mice

The Journal of Cell Biology ◽

10.1083/jcb.200708092 ◽

2007 ◽

Vol 179 (4) ◽

pp. 687-700 ◽

Cited By ~ 41

Author(s):

Debabrata Patra ◽

Xiaoyun Xing ◽

Sherri Davies ◽

Jennifer Bryan ◽

Carl Franz ◽

...

Keyword(s):

Er Stress ◽

Hedgehog Signaling ◽

Endochondral Ossification ◽

Bone Development ◽

Active Form ◽

Type Ii Collagen ◽

Chondrocyte Apoptosis ◽

Endochondral Bone Formation ◽

Endochondral Bone ◽

Er Stress Response

Site-1 protease (S1P) has an essential function in the conversion of latent, membrane-bound transcription factors to their free, active form. In mammals, abundant expression of S1P in chondrocytes suggests an involvement in chondrocyte function. To determine the requirement of S1P in cartilage and bone development, we have created cartilage-specific S1P knockout mice (S1Pcko). S1Pcko mice exhibit chondrodysplasia and a complete lack of endochondral ossification even though Runx2 expression, Indian hedgehog signaling, and osteoblastogenesis is intact. However, there is a substantial increase in chondrocyte apoptosis in the cartilage of S1Pcko mice. Extraction of type II collagen is substantially lower from S1Pcko cartilage. In S1Pcko mice, the collagen network is disorganized and collagen becomes entrapped in chondrocytes. Ultrastructural analysis reveals that the endoplasmic reticulum (ER) in S1Pcko chondrocytes is engorged and fragmented in a manner characteristic of severe ER stress. These data suggest that S1P activity is necessary for a specialized ER stress response required by chondrocytes for the genesis of normal cartilage and thus endochondral ossification.

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Cooperation between p27 and p107 during Endochondral Ossification Suggests a Genetic Pathway Controlled by p27 and p130

Molecular and Cellular Biology ◽

10.1128/mcb.02431-06 ◽

2007 ◽

Vol 27 (14) ◽

pp. 5161-5171 ◽

Cited By ~ 16

Author(s):

Nancy Yeh ◽

Jeffrey P. Miller ◽

Tripti Gaur ◽

Terence D. Capellini ◽

Janko Nikolich-Zugich ◽

...

Keyword(s):

Ex Vivo ◽

Gene Families ◽

Cell Types ◽

Mutant Mice ◽

Endochondral Bone Formation ◽

Cell Type ◽

Mouse Development ◽

Ectopic Ossification ◽

Endochondral Bone ◽

Chondrocyte Maturation

ABSTRACT Pocket proteins and cyclin-dependent kinase (CDK) inhibitors negatively regulate cell proliferation and can promote differentiation. However, which members of these gene families, which cell type they interact in, and what they do to promote differentiation in that cell type during mouse development are largely unknown. To identify the cell types in which p107 and p27 interact, we generated compound mutant mice. These mice were null for p107 and had a deletion in p27 that prevented its binding to cyclin-CDK complexes. Although a fraction of these animals survived into adulthood and looked similar to single p27 mutant mice, a larger number of animals died at birth or within a few weeks thereafter. These animals displayed defects in chondrocyte maturation and endochondral bone formation. Proliferation of chondrocytes was increased, and ectopic ossification was observed. Uncommitted mouse embryo fibroblasts could be induced into the chondrocytic lineage ex vivo, but these cells failed to mature normally. These results demonstrate that p27 carries out overlapping functions with p107 in controlling cell cycle exit during chondrocyte maturation. The phenotypic similarities between p107 −/− p27 D51/D51 and p107 −/− p130 −/− mice and the cells derived from them suggest that p27 and p130 act in an analogous pathway during chondrocyte maturation.

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Juvenile idiopathic arthritis fibroblast-like synoviocytes influence chondrocytes to alter BMP antagonist expression demonstrating an interaction between the two prominent cell types involved in endochondral bone formation

Pediatric Rheumatology ◽

10.1186/s12969-020-00483-0 ◽

2020 ◽

Vol 18 (1) ◽

Author(s):

Megan M. Simonds ◽

Amanda R. Schlefman ◽

Suzanne M. McCahan ◽

Kathleen E. Sullivan ◽

Carlos D. Rose ◽

...

Keyword(s):

Juvenile Idiopathic Arthritis ◽

Synovial Cell ◽

Synovial Fibroblasts ◽

Cell Types ◽

Bmp Signaling ◽

Conditioned Media ◽

Endochondral Bone Formation ◽

Direct Role ◽

Endochondral Bone ◽

Tgfβ Receptors

Abstract Background To examine critical interactions between juvenile idiopathic arthritis synovial fibroblasts (JFLS) and chondrocytes (Ch), and their role in bony overgrowth seen in patients with juvenile idiopathic arthritis (JIA). Methods Control (CFLS) and JFLS were cultured in synoviocyte media containing recombinant BMP4. Ch were cultured in either CFLS or JFLS conditioned-media without stimulation. Media supernatants were analyzed by ELISA. RNA from conditioned media experiment was analyzed by ClariomS microarray. Results As expected, genes expressed in untreated JFLS and CFLS cultured in synoviocyte media were similar to each other and this expression differed from untreated Ch cultured in chondrocyte media. JFLS favor BMP ligand gene expression while downregulating TGFβ receptors’ expression. Noggin and chordin, antagonists with high affinity for BMP4, are JFLS- but not Ch-preferred regulators of BMP signaling. Compared to Ch, JFLS overexpress collagen X (COLX), a marker of chondrocyte hypertrophy. Exogenous BMP4 causes JFLS to significantly decrease expression of noggin and collagen II (COL2), a marker of chondrocyte proliferation, and causes overexpression of COLX and alkaline-phosphatase (ALP). Chondrocytes cultured in JFLS-conditioned media (Ch-JFLS) express BMP genes and favor chordin protein expression over other antagonists. Ch-JFLS have significantly increased expression of COL2 and significantly decreased expression of COLX. Conclusions These data suggest JFLS, in the presence of BMP4, undergo hypertrophy and that JFLS-conditioned media influence chondrocytes to become highly proliferative. To the authors’ knowledge, no prior study has shown that JFLS and chondrocytes play a direct role in the bony overgrowth in joints of patients with JIA and that BMPs or regulation of these growth factors influence the interaction between two prominent synovial cell types.

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Lactoferrin Inhibits IL-1β-Induced Chondrocyte Apoptosis Through AKT1-Induced CREB1 Activation

Cellular Physiology and Biochemistry ◽

10.1159/000430206 ◽

2015 ◽

Vol 36 (6) ◽

pp. 2456-2465 ◽

Cited By ~ 18

Author(s):

Huaming Xue ◽

Yihui Tu ◽

Tong Ma ◽

Xiaodong Liu ◽

Tao Wen ◽

...

Keyword(s):

Western Blotting ◽

Molecular Mechanisms ◽

Articular Chondrocytes ◽

Interleukin 1 ◽

Cartilage Damage ◽

Cartilage Degeneration ◽

Inhibitory Effect ◽

Chondrocyte Apoptosis ◽

Flow Cytometric ◽

Apoptotic Effect

Background/Aims: Chondrocyte apoptosis is largely responsible for cartilage degeneration in osteoarthritis (OA). Interleukin-1 beta (IL-1β) is widely used as a chondrocyte apoptosis-inducing agent, while lactoferrin (LF) is an anabolic reagent which has the potential to inhibit chondrocyte apoptosis. We assessed the effects of LF on cartilage degeneration in IL-1β-induced chondrocytes and in a rat model of OA, and explored the potential molecular mechanisms involved. Methods: Human articular chondrocytes (HACs) were treated with IL-1β alone or in combination with LF. MTT and flow cytometric assays were used to detect changes after treatment with LF. Western blotting was used to examine the relevant molecules regulating apoptosis. Results: We found that IL-1β reduced the viability of HACs, whereas 200 μg/mL of LF significantly counteracted the inhibitory effect of IL-1β. LF significantly inhibited IL-1β-induced HAC apoptosis. The protein expression of the apoptotic markers Caspase-3 and PARP was also significantly reduced in the LF treatment group when analyzed by western blotting. Furthermore, we found that LF triggered CREB1 phosphorylation in IL-1β-induced HAC apoptosis through AKT1 signaling. In addition, LF promoted the repair of articular cartilage damage in a rat OA model with elevated p-CREB levels. Conclusions: These studies suggest that LF has an anti-apoptotic effect on IL-1β-induced chondrocytes, and thus may be a promising novel therapeutic agent for OA.

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Faculty Opinions recommendation of Intraflagellar transport is essential for endochondral bone formation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1059698.511609 ◽

2007 ◽

Author(s):

Peter Scambler

Keyword(s):

Bone Formation ◽

Intraflagellar Transport ◽

Endochondral Bone Formation ◽

Endochondral Bone

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The culture microenvironment of juvenile idiopathic arthritis synovial fibroblasts is favorable for endochondral bone formation through BMP4 and repressed by chondrocytes

Pediatric Rheumatology ◽

10.1186/s12969-021-00556-8 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Megan M. Simonds ◽

Amanda R. Schlefman ◽

Suzanne M. McCahan ◽

Kathleen E. Sullivan ◽

Carlos D. Rose ◽

...

Keyword(s):

Juvenile Idiopathic Arthritis ◽

Bone Formation ◽

Synovial Fibroblasts ◽

Conditioned Media ◽

Endochondral Bone Formation ◽

Endochondral Bone ◽

Member Gene ◽

Bmp Antagonist ◽

Fibroblast Like Synoviocytes ◽

Tgfβ Superfamily

Abstract Background We examined influences of conditioned media from chondrocytes (Ch) on juvenile idiopathic arthritis synovial fibroblasts (JFLS) and potential for JFLS to undergo endochondral bone formation (EBF). Methods Primary cells from three control fibroblast-like synoviocytes (CFLS) and three JFLS were cultured in Ch-conditioned media and compared with untreated fibroblast-like synoviocytes (FLS). RNA was analyzed by ClariomS microarray. FLS cells cultured in conditioned media were exposed to either TGFBR1 inhibitor LY3200882 or exogenous BMP4 and compared with FLS cultured in conditioned media from Ch (JFLS-Ch). Media supernatants were analyzed by ELISA. Results In culture, JFLS downregulate BMP2 and its receptor BMPR1a while upregulating BMP antagonists (NOG and CHRD) and express genes (MMP9, PCNA, MMP12) and proteins (COL2, COLX, COMP) associated with chondrocytes. Important TGFβ superfamily member gene expression (TGFBI, MMP9, COL1A1, SOX6, and MMP2) is downregulated when JFLS are cultured in Ch-conditioned media. COL2, COLX and COMP protein expression decreases in JFLS-Ch. BMP antagonist protein (NOG, CHRD, GREM, and FST) secretion is significantly increased in JFLS-Ch. Protein phosphorylation increases in JFLS-Ch exposed to exogenous BMP4, and chondrocyte-like phenotype is restored in BMP4 presence, evidenced by increased secretion of COL2 and COLX. Inhibition of TGFBR1 in JFLS-Ch results in overexpression of COL2. Conclusions JFLS are chondrocyte-like, and Ch-conditioned media can abrogate this phenotype. The addition of exogenous BMP4 causes JFLS-Ch to restore this chondrocyte-like phenotype, suggesting that JFLS create a microenvironment favorable for endochondral bone formation, thereby contributing to joint growth disturbances in juvenile idiopathic arthritis.

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