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Rj Lories - One of the best experts on this subject based on the ideXlab platform.
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complement component c1q is produced by isolated articular chondrocytes
Osteoarthritis and Cartilage, 2020Co-Authors: R Lubbers, Jc Kwekkeboom, Am Bakker, R A Van Schaarenburg, E W N Levarht, R Mahdad, S Monteagudo, C Cherifi, Rj LoriesAbstract:Summary Objective Inflammation and innate immune responses may contribute to development and progression of Osteoarthritis (OA). Chondrocytes are the sole cell Type of the articular cartilage and produce extracellular-matrix molecules. How inflammatory mediators reach chondrocytes is incompletely understood. Previous studies have shown that chondrocytes express mRNA encoding complement proteins such as C1q, suggesting local protein production, which has not been demonstrated conclusively. The aim of this study is to explore C1q production at the protein level by chondrocytes. Design We analysed protein expression of C1q in freshly isolated and cultured human articular chondrocytes using Western blot, ELISA and flow cytometry. We examined changes in mRNA expression of Collagen, MMP-1 and various complement genes upon stimulation with pro-inflammatory cytokines or C1q. mRNA expression of C1 genes was determined in articular mouse chondrocytes. Results Primary human articular chondrocytes express genes encoding C1q, C1QA, C1QB, C1QC, and secrete C1q to the extracellular medium. Stimulation of chondrocytes with pro-inflammatory cytokines upregulated C1QA, C1QB, C1QC mRNA expression, although this was not confirmed at the protein level. Extracellular C1q bound to the chondrocyte surface dose dependently. In a pilot study, binding of C1q to chondrocytes resulted in changes in the expression of Collagens with a decrease in Collagen Type 2 and an increase in Type 10. Mouse articular chondrocytes also expressed C1QA, C1QB, C1QC, C1R and C1S at the mRNA level. Conclusions C1q protein can be expressed and secreted by human articular chondrocytes and is able to bind to chondrocytes influencing the relative Collagen expression.
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Complement component C1q is produced by isolated articular chondrocytes.
'Elsevier BV', 2020Co-Authors: Lubbers R, Ra ,van Schaarenburg, Jc Kwekkeboom, Levarht Ewn, Am Bakker, Mahdad R, Monteagudo S, Cherifi C, Rj Lories, Toes RemAbstract:OBJECTIVE: Inflammation and innate immune responses may contribute to development and progression of Osteoarthritis (OA). Chondrocytes are the sole cell Type of the articular cartilage and produce extracellular-matrix molecules. How inflammatory mediators reach chondrocytes is incompletely understood. Previous studies have shown that chondrocytes express mRNA encoding complement proteins such as C1q, suggesting local protein production, which has not been demonstrated conclusively. The aim of this study is to explore C1q production at the protein level by chondrocytes. DESIGN: We analysed protein expression of C1q in freshly isolated and cultured human articular chondrocytes using Western blot, ELISA and flow cytometry. We examined changes in mRNA expression of Collagen, MMP-1 and various complement genes upon stimulation with pro-inflammatory cytokines or C1q. mRNA expression of C1 genes was determined in articular mouse chondrocytes. RESULTS: Primary human articular chondrocytes express genes encoding C1q, C1QA, C1QB, C1QC, and secrete C1q to the extracellular medium. Stimulation of chondrocytes with pro-inflammatory cytokines upregulated C1QA, C1QB, C1QC mRNA expression, although this was not confirmed at the protein level. Extracellular C1q bound to the chondrocyte surface dose dependently. In a pilot study, binding of C1q to chondrocytes resulted in changes in the expression of Collagens with a decrease in Collagen Type 2 and an increase in Type 10. Mouse articular chondrocytes also expressed C1QA, C1QB, C1QC, C1R and C1S at the mRNA level. CONCLUSIONS: C1q protein can be expressed and secreted by human articular chondrocytes and is able to bind to chondrocytes influencing the relative Collagen expression.status: publishe
Andrei S Chagin - One of the best experts on this subject based on the ideXlab platform.
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targeted deletion of atg5 in chondrocytes promotes age related osteoarthritis
Annals of the Rheumatic Diseases, 2016Co-Authors: Thibault Bouderlique, Karuna K Vuppalapati, Phillip T Newton, Bjorn Barenius, Andrei S ChaginAbstract:Objectives It has been suggested that the lysosomal recycling process called macro-autophagy plays a role in osteoarthritis development. We thus decided to genetically ablate the autophagy-indispensable Atg5 gene specifically in chondrocytes and analyse the development of osteoarthritis upon aging and in a post-traumatic model. Methods Mice lacking the Atg5 gene in their chondrocytes (Atg5cKO) were generated by crossing Atg5-floxed mice with transgenic mice that expressed cre recombinase driven by the Collagen Type 2 promoter. Animals were analysed at the age of 2, 6 and 12 months for age-related osteoarthritis or underwent mini-open partial medial meniscectomy at 2 months of age and were analysed 1 or 2 months after surgery. We evaluated osteoarthritis using the Osteoarthritis Research Society International (OARSI) scoring on safranin-O-stained samples. Cell death was evaluated by terminal deoxy-nucleotidyl-transferase-mediated deoxy-UTP nick end labelling (TUNEL) and by immunostaining of cleaved caspases. Results We observed the development of osteoarthritis in Atg5cKO mice with aging including fibrillation and loss of proteoglycans, which was particularly severe in males. The ablation of Atg5 was associated with an increased cell death as assessed by TUNEL, cleaved caspase 3 and cleaved caspase 9. Surprisingly, no difference in the development of post-traumatic osteoarthritis was observed between Atg5cKO and control mice. Conclusions Autophagy protects from age-related osteoarthritis by facilitating chondrocyte survival.
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targeted deletion of autophagy genes atg5 or atg7 in the chondrocytes promotes caspase dependent cell death and leads to mild growth retardation
Journal of Bone and Mineral Research, 2015Co-Authors: Karuna K Vuppalapati, Thibault Bouderlique, Phillip T Newton, Vitaliy O Kaminskyy, Henrik Wehtje, Claes Ohlsson, Boris Zhivotovsky, Andrei S ChaginAbstract:Longitudinal bone growth takes place in epiphyseal growth plates located in the ends of long bones. The growth plate consists of chondrocytes traversing from the undifferentiated (resting zone) to the terminally differentiated (hypertrophic zone) stage. Autophagy is an intracellular catabolic process of lysosome-dependent recycling of intracellular organelles and protein complexes. Autophagy is activated during nutritionally depleted or hypoxic conditions in order to facilitate cell survival. Chondrocytes in the middle of the growth plate are hypoxic and nutritionally depleted owing to the avascular nature of the growth plate. Accordingly, autophagy may facilitate their survival. To explore the role of autophagy in chondrocyte survival and constitutional bone growth, we generated mice with cartilage-specific ablation of either Atg5 (Atg5cKO) or Atg7 (Atg7cKO) by crossing Atg5 or Atg7 floxed mice with cartilage-specific Collagen Type 2 promoter-driven Cre. Both Atg5cKO and Atg7cKO mice showed growth retardation associated with enhanced chondrocyte cell death and decreased cell proliferation. Similarly, inhibition of autophagy by Bafilomycin A1 (Baf) or 3-methyladenine (3MA) promoted cell death in cultured slices of human growth plate tissue. To delineate the underlying mechanisms we employed ex vivo cultures of mouse metatarsal bones and RCJ3.IC5.18 rat chondrogenic cell line. Baf or 3MA impaired metatarsal bone growth associated with processing of caspase-3 and massive cell death. Similarly, treatment of RCJ3.IC5.18 chondrogenic cells by Baf also showed massive cell death and caspase-3 cleavage. This was associated with activation of caspase-9 and cytochrome C release. Altogether, our data suggest that autophagy is important for chondrocyte survival, and inhibition of this process leads to stunted growth and caspase-dependent death of chondrocytes.
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targeted deletion of autophagy genes atg5 or atg7 in the chondrocytes promotes caspase dependent cell death and leads to mild growth retardation
Journal of Bone and Mineral Research, 2015Co-Authors: Karuna K Vuppalapati, Thibault Bouderlique, Phillip T Newton, Vitaliy O Kaminskyy, Henrik Wehtje, Claes Ohlsson, Boris Zhivotovsky, Andrei S ChaginAbstract:Longitudinal bone growth takes place in epiphyseal growth plates located in the ends of long bones. The growth plate consists of chondrocytes traversing from the undifferentiated (resting zone) to the terminally differentiated (hypertrophic zone) stage. Autophagy is an intracellular catabolic process of lysosome-dependent recycling of intracellular organelles and protein complexes. Autophagy is activated during nutritionally depleted or hypoxic conditions in order to facilitate cell survival. Chondrocytes in the middle of the growth plate are hypoxic and nutritionally depleted owing to the avascular nature of the growth plate. Accordingly, autophagy may facilitate their survival. To explore the role of autophagy in chondrocyte survival and constitutional bone growth, we generated mice with cartilage-specific ablation of either Atg5 (Atg5cKO) or Atg7 (Atg7cKO) by crossing Atg5 or Atg7 floxed mice with cartilage-specific Collagen Type 2 promoter–driven Cre. Both Atg5cKO and Atg7cKO mice showed growth retardation associated with enhanced chondrocyte cell death and decreased cell proliferation. Similarly, inhibition of autophagy by Bafilomycin A1 (Baf) or 3-methyladenine (3MA) promoted cell death in cultured slices of human growth plate tissue. To delineate the underlying mechanisms we employed ex vivo cultures of mouse metatarsal bones and RCJ3.IC5.18 rat chondrogenic cell line. Baf or 3MA impaired metatarsal bone growth associated with processing of caspase-3 and massive cell death. Similarly, treatment of RCJ3.IC5.18 chondrogenic cells by Baf also showed massive cell death and caspase-3 cleavage. This was associated with activation of caspase-9 and cytochrome C release. Altogether, our data suggest that autophagy is important for chondrocyte survival, and inhibition of this process leads to stunted growth and caspase-dependent death of chondrocytes. © 2015 American Society for Bone and Mineral Research.
R A Van Schaarenburg - One of the best experts on this subject based on the ideXlab platform.
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complement component c1q is produced by isolated articular chondrocytes
Osteoarthritis and Cartilage, 2020Co-Authors: R Lubbers, Jc Kwekkeboom, Am Bakker, R A Van Schaarenburg, E W N Levarht, R Mahdad, S Monteagudo, C Cherifi, Rj LoriesAbstract:Summary Objective Inflammation and innate immune responses may contribute to development and progression of Osteoarthritis (OA). Chondrocytes are the sole cell Type of the articular cartilage and produce extracellular-matrix molecules. How inflammatory mediators reach chondrocytes is incompletely understood. Previous studies have shown that chondrocytes express mRNA encoding complement proteins such as C1q, suggesting local protein production, which has not been demonstrated conclusively. The aim of this study is to explore C1q production at the protein level by chondrocytes. Design We analysed protein expression of C1q in freshly isolated and cultured human articular chondrocytes using Western blot, ELISA and flow cytometry. We examined changes in mRNA expression of Collagen, MMP-1 and various complement genes upon stimulation with pro-inflammatory cytokines or C1q. mRNA expression of C1 genes was determined in articular mouse chondrocytes. Results Primary human articular chondrocytes express genes encoding C1q, C1QA, C1QB, C1QC, and secrete C1q to the extracellular medium. Stimulation of chondrocytes with pro-inflammatory cytokines upregulated C1QA, C1QB, C1QC mRNA expression, although this was not confirmed at the protein level. Extracellular C1q bound to the chondrocyte surface dose dependently. In a pilot study, binding of C1q to chondrocytes resulted in changes in the expression of Collagens with a decrease in Collagen Type 2 and an increase in Type 10. Mouse articular chondrocytes also expressed C1QA, C1QB, C1QC, C1R and C1S at the mRNA level. Conclusions C1q protein can be expressed and secreted by human articular chondrocytes and is able to bind to chondrocytes influencing the relative Collagen expression.
Marco N Helder - One of the best experts on this subject based on the ideXlab platform.
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hyperosmolarity and hypoxia induce chondrogenesis of adipose derived stem cells in a Collagen Type 2 hydrogel
Journal of Tissue Engineering and Regenerative Medicine, 2012Co-Authors: Wouter J F M Jurgens, Behrouz Zandiehdoulabi, Dirk J Kuik, Marco J P F Ritt, Marco N HelderAbstract:Apart from soluble growth factors, various other biophysicochemical cues are known to promote chondrogenesis. Under physiological conditions, cartilage in the joint comprises a hyperosmotic and hypoxic environment. Therefore, in this study, we examined the inductive effects of hyperosmotic and/or hypoxic conditions on adipose stem cells (ASCs) and compared them with conventional TGFβ1-induction. After encapsulation in Collagen Type II hydrogels and specific induction, ASCs were assessed for viability, proliferation, morphology and chondrogenic differentiation potential. Viability was similar under all conditions, with low proliferative activity. After 4 days, hypoxia and/or hyperosmolarity did not affect round cell morphology, while cells were mainly stretched in the TGFβ1-induced group. At 21 days, the TGFs1-treated group had aggregated into a cell nodule. Hyperosmolarity mimicked this aggregation to a lesser extent, whereas cells under hypoxia stretched out after 21 days, with a combined effect in the hypoxic/hyperosmotic group. Both individual and combined hyperosmotic and/or hypoxic conditions significantly upregulated SOX5, SOX9, COMP and Link-p gene expression compared with the non-induced group, and to similar levels as the TGFβ1-induced group. GAG synthesis in both hydrogel and medium was increased under hypoxic conditions, whereas hyperosmolarity decreased GAG formation in the hydrogels, but increased GAG formation in the medium. We conclude that in a joint mimicking the three-dimensional (3D) micro-environment, a combination of hyperosmolarity and hypoxia is able to induce chondrogenesis to the same extent as TGFβ1. This might lead to an interesting alternative when considering short-term triggering in a one-step surgical procedure for the treatment of cartilaginous defects. Copyright © 2011 John Wiley & Sons, Ltd.
Karuna K Vuppalapati - One of the best experts on this subject based on the ideXlab platform.
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targeted deletion of atg5 in chondrocytes promotes age related osteoarthritis
Annals of the Rheumatic Diseases, 2016Co-Authors: Thibault Bouderlique, Karuna K Vuppalapati, Phillip T Newton, Bjorn Barenius, Andrei S ChaginAbstract:Objectives It has been suggested that the lysosomal recycling process called macro-autophagy plays a role in osteoarthritis development. We thus decided to genetically ablate the autophagy-indispensable Atg5 gene specifically in chondrocytes and analyse the development of osteoarthritis upon aging and in a post-traumatic model. Methods Mice lacking the Atg5 gene in their chondrocytes (Atg5cKO) were generated by crossing Atg5-floxed mice with transgenic mice that expressed cre recombinase driven by the Collagen Type 2 promoter. Animals were analysed at the age of 2, 6 and 12 months for age-related osteoarthritis or underwent mini-open partial medial meniscectomy at 2 months of age and were analysed 1 or 2 months after surgery. We evaluated osteoarthritis using the Osteoarthritis Research Society International (OARSI) scoring on safranin-O-stained samples. Cell death was evaluated by terminal deoxy-nucleotidyl-transferase-mediated deoxy-UTP nick end labelling (TUNEL) and by immunostaining of cleaved caspases. Results We observed the development of osteoarthritis in Atg5cKO mice with aging including fibrillation and loss of proteoglycans, which was particularly severe in males. The ablation of Atg5 was associated with an increased cell death as assessed by TUNEL, cleaved caspase 3 and cleaved caspase 9. Surprisingly, no difference in the development of post-traumatic osteoarthritis was observed between Atg5cKO and control mice. Conclusions Autophagy protects from age-related osteoarthritis by facilitating chondrocyte survival.
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targeted deletion of autophagy genes atg5 or atg7 in the chondrocytes promotes caspase dependent cell death and leads to mild growth retardation
Journal of Bone and Mineral Research, 2015Co-Authors: Karuna K Vuppalapati, Thibault Bouderlique, Phillip T Newton, Vitaliy O Kaminskyy, Henrik Wehtje, Claes Ohlsson, Boris Zhivotovsky, Andrei S ChaginAbstract:Longitudinal bone growth takes place in epiphyseal growth plates located in the ends of long bones. The growth plate consists of chondrocytes traversing from the undifferentiated (resting zone) to the terminally differentiated (hypertrophic zone) stage. Autophagy is an intracellular catabolic process of lysosome-dependent recycling of intracellular organelles and protein complexes. Autophagy is activated during nutritionally depleted or hypoxic conditions in order to facilitate cell survival. Chondrocytes in the middle of the growth plate are hypoxic and nutritionally depleted owing to the avascular nature of the growth plate. Accordingly, autophagy may facilitate their survival. To explore the role of autophagy in chondrocyte survival and constitutional bone growth, we generated mice with cartilage-specific ablation of either Atg5 (Atg5cKO) or Atg7 (Atg7cKO) by crossing Atg5 or Atg7 floxed mice with cartilage-specific Collagen Type 2 promoter-driven Cre. Both Atg5cKO and Atg7cKO mice showed growth retardation associated with enhanced chondrocyte cell death and decreased cell proliferation. Similarly, inhibition of autophagy by Bafilomycin A1 (Baf) or 3-methyladenine (3MA) promoted cell death in cultured slices of human growth plate tissue. To delineate the underlying mechanisms we employed ex vivo cultures of mouse metatarsal bones and RCJ3.IC5.18 rat chondrogenic cell line. Baf or 3MA impaired metatarsal bone growth associated with processing of caspase-3 and massive cell death. Similarly, treatment of RCJ3.IC5.18 chondrogenic cells by Baf also showed massive cell death and caspase-3 cleavage. This was associated with activation of caspase-9 and cytochrome C release. Altogether, our data suggest that autophagy is important for chondrocyte survival, and inhibition of this process leads to stunted growth and caspase-dependent death of chondrocytes.
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targeted deletion of autophagy genes atg5 or atg7 in the chondrocytes promotes caspase dependent cell death and leads to mild growth retardation
Journal of Bone and Mineral Research, 2015Co-Authors: Karuna K Vuppalapati, Thibault Bouderlique, Phillip T Newton, Vitaliy O Kaminskyy, Henrik Wehtje, Claes Ohlsson, Boris Zhivotovsky, Andrei S ChaginAbstract:Longitudinal bone growth takes place in epiphyseal growth plates located in the ends of long bones. The growth plate consists of chondrocytes traversing from the undifferentiated (resting zone) to the terminally differentiated (hypertrophic zone) stage. Autophagy is an intracellular catabolic process of lysosome-dependent recycling of intracellular organelles and protein complexes. Autophagy is activated during nutritionally depleted or hypoxic conditions in order to facilitate cell survival. Chondrocytes in the middle of the growth plate are hypoxic and nutritionally depleted owing to the avascular nature of the growth plate. Accordingly, autophagy may facilitate their survival. To explore the role of autophagy in chondrocyte survival and constitutional bone growth, we generated mice with cartilage-specific ablation of either Atg5 (Atg5cKO) or Atg7 (Atg7cKO) by crossing Atg5 or Atg7 floxed mice with cartilage-specific Collagen Type 2 promoter–driven Cre. Both Atg5cKO and Atg7cKO mice showed growth retardation associated with enhanced chondrocyte cell death and decreased cell proliferation. Similarly, inhibition of autophagy by Bafilomycin A1 (Baf) or 3-methyladenine (3MA) promoted cell death in cultured slices of human growth plate tissue. To delineate the underlying mechanisms we employed ex vivo cultures of mouse metatarsal bones and RCJ3.IC5.18 rat chondrogenic cell line. Baf or 3MA impaired metatarsal bone growth associated with processing of caspase-3 and massive cell death. Similarly, treatment of RCJ3.IC5.18 chondrogenic cells by Baf also showed massive cell death and caspase-3 cleavage. This was associated with activation of caspase-9 and cytochrome C release. Altogether, our data suggest that autophagy is important for chondrocyte survival, and inhibition of this process leads to stunted growth and caspase-dependent death of chondrocytes. © 2015 American Society for Bone and Mineral Research.