scholarly journals Joint degeneration in a mouse model of pseudoachondroplasia: ER stress, inflammation and autophagy blockage

2021 ◽  
Author(s):  
Jacqueline T Hecht ◽  
Alka C Veerisetty ◽  
Mohammad G Hossain ◽  
Debabrata Patra ◽  
Frankie Chiu ◽  
...  
Keyword(s):  
Er Stress ◽  
Matrix Protein ◽  
Articular Chondrocytes ◽  
Joint Degeneration ◽  
Articular Chondrocyte ◽  
Major Mechanism ◽  
Chondrocyte Death ◽  
Joint Health ◽  
Degradative Enzymes ◽  
Cellular Stresses

Pseudoachondroplasia (PSACH), a short limb skeletal dysplasia, associated with premature joint degeneration is caused by misfolding mutations in cartilage oligomeric matrix protein (COMP). Here, we define mutant-COMP-induced stress mechanisms that occur in articular chondrocytes of MT-COMP mice, a murine model of PSACH. The accumulation of mutant-COMP in the ER occurred early in MT-COMP articular chondrocytes and stimulated inflammation (TNFα) at 4 wks. Articular chondrocyte death increased at 8 wks and ER stress through CHOP was elevated by 12 wks. Importantly, blockage of autophagy (pS6), the major mechanism which clears the ER, sustained cellular stress in MT-COMP articular chondrocytes. Degeneration of MT-COMP articular cartilage was similar to that observed in PSACH and was associated with increased MMPs, degradative enzymes. Moreover, chronic cellular stresses stimulated senescence. Senescence-associated secretory phenotype (SASP) may play a role in generating and propagating a pro-degradative environment in the MT-COMP murine joint. The loss of CHOP or resveratrol treatment from birth preserved joint health in MT-COMP mice. Taken together, these results indicate that ER stress/CHOP signaling and autophagy blockage are central to mutant-COMP joint degeneration and MT-COMP mice joint health can be preserved by decreasing articular chondrocyte stress. Future joint sparing therapeutics for PSACH may include resveratrol.

scholarly journals Joint Degeneration in a Mouse Model of Pseudoachondroplasia: ER Stress, Inflammation, and Block of Autophagy

2021 ◽  
Vol 22 (17) ◽  
pp. 9239
Author(s):  
Jacqueline T. Hecht ◽  
Alka C. Veerisetty ◽  
Mohammad G. Hossain ◽  
Debabrata Patra ◽  
Frankie Chiu ◽  
...  
Keyword(s):  
Er Stress ◽  
Matrix Protein ◽  
Articular Chondrocytes ◽  
Joint Degeneration ◽  
Articular Chondrocyte ◽  
Major Mechanism ◽  
Chondrocyte Death ◽  
Joint Health ◽  
Degradative Enzymes ◽  
Cellular Stresses

Pseudoachondroplasia (PSACH), a short limb skeletal dysplasia associated with premature joint degeneration, is caused by misfolding mutations in cartilage oligomeric matrix protein (COMP). Here, we define mutant-COMP-induced stress mechanisms that occur in articular chondrocytes of MT-COMP mice, a murine model of PSACH. The accumulation of mutant-COMP in the ER occurred early in MT-COMP articular chondrocytes and stimulated inflammation (TNFα) at 4 weeks, and articular chondrocyte death increased at 8 weeks while ER stress through CHOP was elevated by 12 weeks. Importantly, blockage of autophagy (pS6), the major mechanism that clears the ER, sustained cellular stress in MT-COMP articular chondrocytes. Degeneration of MT-COMP articular cartilage was similar to that observed in PSACH and was associated with increased MMPs, a family of degradative enzymes. Moreover, chronic cellular stresses stimulated senescence. Senescence-associated secretory phenotype (SASP) may play a role in generating and propagating a pro-degradative environment in the MT-COMP murine joint. The loss of CHOP or resveratrol treatment from birth preserved joint health in MT-COMP mice. Taken together, these results indicate that ER stress/CHOP signaling and autophagy blockage are central to mutant-COMP joint degeneration, and MT-COMP mice joint health can be preserved by decreasing articular chondrocyte stress. Future joint sparing therapeutics for PSACH may include resveratrol.

scholarly journals A VCP modulator, KUS121, as a promising therapeutic agent for post-traumatic osteoarthritis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Motoo Saito ◽  
Kohei Nishitani ◽  
Hanako O. Ikeda ◽  
Shigeo Yoshida ◽  
Sachiko Iwai ◽  
...  
Keyword(s):  
Cell Death ◽  
Er Stress ◽  
Therapeutic Agent ◽  
Articular Chondrocytes ◽  
Cartilage Explants ◽  
Chondrocyte Death ◽  
Post Traumatic ◽  
Promising Therapeutic Agent

AbstractPost-traumatic osteoarthritis (PTOA) is a major cause which hinders patients from the recovery after intra-articular injuries or surgeries. Currently, no effective treatment is available. In this study, we showed that inhibition of the acute stage chondrocyte death is a promising strategy to mitigate the development of PTOA. Namely, we examined efficacies of Kyoto University Substance (KUS) 121, a valosin-containing protein modulator, for PTOA as well as its therapeutic mechanisms. In vivo, in a rat PTOA model by cyclic compressive loading, intra-articular treatments of KUS121 significantly improved the modified Mankin scores and reduced damaged-cartilage volumes, as compared to vehicle treatment. Moreover, KUS121 markedly reduced the numbers of TUNEL-, CHOP-, MMP-13-, and ADAMTS-5-positive chondrocytes in the damaged knees. In vitro, KUS121 rescued human articular chondrocytes from tunicamycin-induced cell death, in both monolayer culture and cartilage explants. It also significantly downregulated the protein or gene expression of ER stress markers, proinflammatory cytokines, and extracellular-matrix-degrading enzymes induced by tunicamycin or IL-1β. Collectively, these results demonstrated that KUS121 protected chondrocytes from cell death through the inhibition of excessive ER stress. Therefore, KUS121 would be a new, promising therapeutic agent with a protective effect on the progression of PTOA.

scholarly journals Molecular and Cellular Effects of Chemical Chaperone—TUDCA on ER-Stressed NHAC-kn Human Articular Chondrocytes Cultured in Normoxic and Hypoxic Conditions

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 878
Author(s):  
Magdalena Kusaczuk ◽  
Monika Naumowicz ◽  
Rafał Krętowski ◽  
Bartosz Cukierman ◽  
Marzanna Cechowska-Pasko
Keyword(s):  
Er Stress ◽  
Articular Chondrocytes ◽  
Potential Candidate ◽  
Chemical Chaperone ◽  
Cellular Effects ◽  
Chop Expression ◽  
Hypoxic Conditions ◽  
Stressed Cells ◽  
Apoptotic Activity ◽  
Potential Therapeutics

Osteoarthritis (OA) is considered one of the most common arthritic diseases characterized by progressive degradation and abnormal remodeling of articular cartilage. Potential therapeutics for OA aim at restoring proper chondrocyte functioning and inhibiting apoptosis. Previous studies have demonstrated that tauroursodeoxycholic acid (TUDCA) showed anti-inflammatory and anti-apoptotic activity in many models of various diseases, acting mainly via alleviation of endoplasmic reticulum (ER) stress. However, little is known about cytoprotective effects of TUDCA on chondrocyte cells. The present study was designed to evaluate potential effects of TUDCA on interleukin-1β (IL-1β) and tunicamycin (TNC)-stimulated NHAC-kn chondrocytes cultured in normoxic and hypoxic conditions. Our results showed that TUDCA alleviated ER stress in TNC-treated chondrocytes, as demonstrated by reduced CHOP expression; however, it was not effective enough to prevent apoptosis of NHAC-kn cells in either normoxia nor hypoxia. However, co-treatment with TUDCA alleviated inflammatory response induced by IL-1β, as shown by down regulation of Il-1β, Il-6, Il-8 and Cox2, and increased the expression of antioxidant enzyme Sod2. Additionally, TUDCA enhanced Col IIα expression in IL-1β- and TNC-stimulated cells, but only in normoxic conditions. Altogether, these results suggest that although TUDCA may display chondoprotective potential in ER-stressed cells, further analyses are still necessary to fully confirm its possible recommendation as potential candidate in OA therapy.

scholarly journals Calcium Input Potentiates the Transforming Growth Factor (TGF)-β1-dependent Signaling to Promote the Export of Inorganic Pyrophosphate by Articular Chondrocyte

2011 ◽  
Vol 286 (22) ◽  
pp. 19215-19228 ◽  
Author(s):  
Frederic Cailotto ◽  
Pascal Reboul ◽  
Sylvie Sebillaud ◽  
Patrick Netter ◽  
Jean-Yves Jouzeau ◽  
...  
Keyword(s):  
Growth Factor ◽  
Promoter Activity ◽  
Transforming Growth Factor ◽  
Articular Chondrocytes ◽  
Specific Protein ◽  
Dependent Manner ◽  
Articular Chondrocyte ◽  
Experimental Conditions ◽  
Inorganic Pyrophosphate ◽  
Tgf Β1

Transforming growth factor (TGF)-β1 stimulates extracellular PPi (ePPi) generation and promotes chondrocalcinosis, which also occurs secondary to hyperparathyroidism-induced hypercalcemia. We previously demonstrated that ANK was up-regulated by TGF-β1 activation of ERK1/2 and Ca2+-dependent protein kinase C (PKCα). Thus, we investigated mechanisms by which calcium could affect ePPi metabolism, especially its main regulating proteins ANK and PC-1 (plasma cell membrane glycoprotein-1). We stimulated articular chondrocytes with TGF-β1 under extracellular (eCa2+) or cytosolic Ca2+ (cCa2+) modulations. We studied ANK, PC-1 expression (quantitative RT-PCR, Western blotting), ePPi levels (radiometric assay), and cCa2+ input (fluorescent probe). Voltage-operated Ca2+-channels (VOC) and signaling pathways involved were investigated with selective inhibitors. Finally, Ank promoter activity was evaluated (gene reporter). TGF-β1 elevated cCa2+ and ePPi levels (by up-regulating Ank and PC-1 mRNA/proteins) in an eCa2+ dose-dependent manner. TGF-β1 effects were suppressed by cCa2+ chelation or L- and T-VOC blockade while being mostly reproduced by ionomycin. In the same experimental conditions, the activation of Ras, the phosphorylation of ERK1/2 and PKCα, and the stimulation of Ank promoter activity were affected similarly. Activation of SP1 (specific protein 1) and ELK-1 (Ets-like protein-1) transcription factors supported the regulatory role of Ca2+. SP1 or ELK-1 overexpression or blockade experiments demonstrated a major contribution of ELK-1, which acted synergistically with SP1 to activate Ank promoter in response to TGF-β1. TGF-β1 promotes input of eCa2+ through opening of L- and T-VOCs, to potentiate ERK1/2 and PKCα signaling cascades, resulting in an enhanced activation of Ank promoter and ePPi production in chondrocyte.

scholarly journals GSK5182, 4-Hydroxytamoxifen Analog, a New Potential Therapeutic Drug for Osteoarthritis

2020 ◽  
Vol 13 (12) ◽  
pp. 429
Author(s):  
Yunhui Min ◽  
Dahye Kim ◽  
Godagama Gamaarachchige Dinesh Suminda ◽  
Xiangyu Zhao ◽  
Mangeun Kim ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Small Molecule ◽  
Articular Chondrocytes ◽  
Therapeutic Potential ◽  
Inverse Agonist ◽  
Therapeutic Drug ◽  
Articular Chondrocyte ◽  
Orphan Nuclear Receptors ◽  
Genetic Ablation ◽  
Pro Inflammatory Cytokines

Estrogen-related receptors (ERRs) are the first identified orphan nuclear receptors. The ERR family consists of ERRα, ERRβ, and ERRγ, regulating diverse isoform-specific functions. We have reported the importance of ERRγ in osteoarthritis (OA) pathogenesis. However, therapeutic approaches with ERRγ against OA associated with inflammatory mechanisms remain limited. Herein, we examined the therapeutic potential of a small-molecule ERRγ inverse agonist, GSK5182 (4-hydroxytamoxifen analog), in OA, to assess the relationship between ERRγ expression and pro-inflammatory cytokines in mouse articular chondrocyte cultures. ERRγ expression increased following chondrocyte exposure to various pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Pro-inflammatory cytokines dose-dependently increased ERRγ protein levels. In mouse articular chondrocytes, adenovirus-mediated ERRγ overexpression upregulated matrix metalloproteinase (MMP)-3 and MMP-13, which participate in cartilage destruction during OA. Adenovirus-mediated ERRγ overexpression in mouse knee joints or ERRγ transgenic mice resulted in OA. In mouse joint tissues, genetic ablation of Esrrg obscured experimental OA. These results indicate that ERRγ is involved in OA pathogenesis. In mouse articular chondrocytes, GSK5182 inhibited pro-inflammatory cytokine-induced catabolic factors. Consistent with the in vitro results, GSK5182 significantly reduced cartilage degeneration in ERRγ-overexpressing mice administered intra-articular Ad-Esrrg. Overall, the ERRγ inverse agonist GSK5182 represents a promising therapeutic small molecule for OA.

scholarly journals High-Throughput Identification of MiR-145 Targets in Human Articular Chondrocytes

Life ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 58
Author(s):  
Aida Martinez-Sanchez ◽  
Stefano Lazzarano ◽  
Eshita Sharma ◽  
Helen Lockstone ◽  
Christopher L. Murphy
Keyword(s):  
Cartilage Repair ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Articular Chondrocytes ◽  
Articular Chondrocyte ◽  
Coding Region ◽  
Cartilage Development ◽  
Rna Immunoprecipitation ◽  
Important Regulator ◽  
Mmp13 Expression

MicroRNAs (miRNAs) play key roles in cartilage development and homeostasis and are dysregulated in osteoarthritis. MiR-145 modulation induces profound changes in the human articular chondrocyte (HAC) phenotype, partially through direct repression of SOX9. Since miRNAs can simultaneously silence multiple targets, we aimed to identify the whole targetome of miR-145 in HACs, critical if miR-145 is to be considered a target for cartilage repair. We performed RIP-seq (RNA-immunoprecipitation and high-throughput sequencing) of miRISC (miRNA-induced silencing complex) in HACs overexpressing miR-145 to identify miR-145 direct targets and used cWords to assess enrichment of miR-145 seed matches in the identified targets. Further validations were performed by RT-qPCR, Western immunoblot, and luciferase assays. MiR-145 affects the expression of over 350 genes and directly targets more than 50 mRNAs through the 3′UTR or, more commonly, the coding region. MiR-145 targets DUSP6, involved in cartilage organization and development, at the translational level. DUSP6 depletion leads to MMP13 upregulation, suggesting a contribution towards the effect of miR-145 on MMP13 expression. In conclusion, miR-145 directly targets several genes involved in the expression of the extracellular matrix and inflammation in primary chondrocytes. Thus, we propose miR-145 as an important regulator of chondrocyte function and a new target for cartilage repair.

scholarly journals Genesis of ER stress in Huntington’s Disease

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Marina Shenkman ◽  
Hagit Eiger ◽  
Gerardo Z. Lederkremer
Keyword(s):  
Neurodegenerative Diseases ◽  
Er Stress ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Late Onset ◽  
Genetic Disorder ◽  
Effective Therapy ◽  
Major Mechanism ◽  
Shed Light

AbstractRecent research has identified ER stress as a major mechanism implicated in cytotoxicity in many neurodegenerative diseases, among them Huntington’s disease. This genetic disorder is of late-onset, progressive and fatal, affecting cognition and movement. There is presently no cure nor any effective therapy for the disease. This review focuses on recent findings that shed light on the mechanisms of the advent and development of ER stress in Huntington’s disease and on its implications, highlighting possible therapeutic avenues that are being or could be explored.

scholarly journals Erratum: Wnt/β-catenin signaling stimulates matrix catabolic genes and activity in articular chondrocytes: its possible role in joint degeneration

2008 ◽  
Vol 88 (4) ◽  
pp. 451-451 ◽  
Author(s):  
Takahito Yuasa ◽  
Tomohiro Otani ◽  
Tatsuya Koike ◽  
Masahiro Iwamoto ◽  
Motomi Enomoto-Iwamoto
Keyword(s):  
Articular Chondrocytes ◽  
Joint Degeneration ◽  
Catabolic Genes

scholarly journals Transcription Factor Erg Variants and Functional Diversification of Chondrocytes during Limb Long Bone Development

2000 ◽  
Vol 150 (1) ◽  
pp. 27-40 ◽  
Author(s):  
Masahiro Iwamoto ◽  
Yoshinobu Higuchi ◽  
Eiki Koyama ◽  
Motomi Enomoto-Iwamoto ◽  
Kojiro Kurisu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Limb Development ◽  
Matrix Protein ◽  
Molecular Mechanisms ◽  
Articular Chondrocytes ◽  
Bone Cells ◽  
Expression Patterns ◽  
Extracellular Matrix Protein ◽  
Long Bone ◽  
Chondrocyte Maturation

During limb development, chondrocytes located at the epiphyseal tip of long bone models give rise to articular tissue, whereas the more numerous chondrocytes in the shaft undergo maturation, hypertrophy, and mineralization and are replaced by bone cells. It is not understood how chondrocytes follow these alternative pathways to distinct fates and functions. In this study we describe the cloning of C-1-1, a novel variant of the ets transcription factor ch-ERG. C-1-1 lacks a short 27–amino acid segment located ∼80 amino acids upstream of the ets DNA binding domain. We found that in chick embryo long bone anlagen, C-1-1 expression characterizes developing articular chondrocytes, whereas ch-ERG expression is particularly prominent in prehypertrophic chondrocytes in the growth plate. To analyze the function of C-1-1 and ch-ERG, viral vectors were used to constitutively express each factor in developing chick leg buds and cultured chondrocytes. We found that virally driven expression of C-1-1 maintained chondrocytes in a stable and immature phenotype, blocked their maturation into hypertrophic cells, and prevented the replacement of cartilage with bone. It also induced synthesis of tenascin-C, an extracellular matrix protein that is a unique product of developing articular chondrocytes. In contrast, virally driven expression of ch-ERG significantly stimulated chondrocyte maturation in culture, as indicated by increases in alkaline phosphatase activity and deposition of a mineralized matrix; however, it had modest effects in vivo. The data show that C-1-1 and ch-ERG have diverse biological properties and distinct expression patterns during skeletogenesis, and are part of molecular mechanisms by which limb chondrocytes follow alternative developmental pathways. C-1-1 is the first transcription factor identified to date that appears to be instrumental in the genesis and function of epiphyseal articular chondrocytes.

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