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

2015 ◽  
Vol 36 (6) ◽  
pp. 2456-2465 ◽  
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.

An Insight into the Role of Apoptosis and Autophagy in Nitric Oxide–Induced Articular Chondrocyte Cell Death

Cartilage ◽  
2020 ◽  
pp. 194760352097676
Author(s):  
Ekkapol Akaraphutiporn ◽  
Takafumi Sunaga ◽  
Eugene C. Bwalya ◽  
Wang Yanlin ◽  
Mwale Carol ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cell Death ◽  
Western Blot ◽  
Cell Apoptosis ◽  
Molecular Mechanisms ◽  
Interleukin 1 ◽  
Chondrocyte Apoptosis ◽  
Protective Mechanism ◽  
Autophagic Flux ◽  
Qpcr Analysis

Objective To investigate the role and characterize the molecular mechanisms regulating apoptosis and autophagy in nitric oxide (NO)–induced chondrocyte cell death. Design Cell apoptosis and autophagy were evaluated in chondrocytes treated with sodium nitroprusside (SNP) combined with the presence or absence of interleukin-1 beta (IL-1β) and nutrient-deprived conditions. The concentration of nitrite was determined by Griess reaction. Activation of apoptosis and autophagy were determined by immunocytochemistry, Western blot, and quantitative real-time polymerase chain reaction (qPCR) analysis. Flow cytometry and MTT assay were used to assess cell viability. Results Cotreatment of chondrocytes with SNP and IL-1β under nutrient-deprived condition potentially enhanced the effect of NO-induced cell death. Immunocytochemistry, Western blot, and qPCR analysis indicated that treatment of chondrocytes with SNP significantly reduced autophagic activity, autophagic flux, and multiple autophagy-related (Atg) genes expression. These findings were associated with an increase in ERK, Akt, and mTOR phosphorylation, whereas autophagy induction through mTOR/p70S6K inhibition by rapamycin significantly suppressed NO-induced cell apoptosis. Furthermore, the cleavage of poly(ADP-ribose) polymerase (PARP) and caspase-3 activation in response to apoptosis was weakly detected. These results corresponded with a significant increase in apoptosis-inducing factor (AIF) expression, suggesting the involvement of the caspase-independent pathway. Conclusions These results demonstrate that in chondrocyte cultures with cells induced into an osteoarthritis state, NO inhibits autophagy and induces chondrocyte apoptosis mainly, but not completely through the caspase-independent pathway. Our data suggest that autophagy is a protective mechanism in the pathogenesis of osteoarthritis and could be proposed as a therapeutic target for degenerative joint diseases.

scholarly journals Prolactin inhibits the apoptosis of chondrocytes induced by serum starvation

2006 ◽  
Vol 189 (2) ◽  
pp. R1-R8 ◽  
Author(s):  
C Zermeño ◽  
J Guzmán-Morales ◽  
Y Macotela ◽  
G Nava ◽  
F López-Barrera ◽  
...  
Keyword(s):  
Articular Chondrocytes ◽  
Cell Types ◽  
Cartilage Degradation ◽  
Chondrocyte Apoptosis ◽  
Heat Inactivation ◽  
Serum Starvation ◽  
Endochondral Bone Formation ◽  
Endochondral Bone ◽  
Therapeutic Value ◽  
Apoptotic Effect

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.

scholarly journals Knockdown of LSD1 alleviates the IL-1β-induced chondrocyte apoptosis, inflammation and ECM degradation via TRIM32-mediated autophagy

2021 ◽  
Author(s):  
Wenqiang Xu ◽  
Xiaofeng Liu ◽  
Wenqing Qu ◽  
Xin Wang ◽  
Hao Su ◽  
...  
Keyword(s):  
Cell Model ◽  
Interleukin 1 ◽  
Cartilage Degeneration ◽  
Joint Disease ◽  
Chondrocyte Apoptosis ◽  
Interleukin 1 Beta ◽  
Chondrocyte Viability ◽  
A Cell ◽  
Ecm Degradation ◽  
Articular Cartilage Degeneration

Abstract Osteoarthritis (OA) is a common joint disease with characteristics of chronic inflammation and articular cartilage degeneration. It has been proved that LSD1 was up-regulated in OA cartilage tissues, but its role and regulatory mechanism in OA are unclear. Herein, interleukin 1 beta (IL-1β)-treated human chondrocytes was performed as a cell model of OA. Then, LSD1 expression was found that up-regulated in OA cartilage tissues and IL-1β-induced chondrocytes. Knockdown of LSD1 increased cell viability, while decreased apoptosis rate and inflammatory cytokines secretion levels in IL-1β-induced chondrocytes. In addition, knockdown of LSD1 reduced the expression of catabolic proteins (MMP-13 and ADAMTS-5) and enhanced the expression of anabolic proteins (Collagen II and Aggrecan) in chondrocytes after IL-1β stimulation. Moreover, overexpression of TRIM32 repressed chondrocyte viability, while promoted IL-1β-induced chondrocyte apoptosis, inflammation and ECM degradation. The expression of LSD1 and TRIM32 in OA cartilage was positively correlated, and knockdown of LSD1 down-regulated TRIM32 expression of chondrocytes. Our data further indicated that LSD1 regulated autophagy of chondrocytes through modulating TRIM32. Overexpression of TRIM32 reduced the effect of LSD1 knockdown on IL-1β-induced chondrocytes, while activating autophagy by Rapamycin further reversed this reduction. Therefore, our study shows that knockdown of LSD1 inhibited IL-1β-induced chondrocyte apoptosis, inflammation and ECM degradation via TRIM32-mediated autophagy.

scholarly journals Rapamycin microparticles induce autophagy, prevent senescence and are effective in treatment of Osteoarthritis

2021 ◽  
Author(s):  
Kaamini M Dhanabalan ◽  
Ameya A Dravid ◽  
Smriti Agarwal ◽  
Ramanath K Sharath ◽  
Ashok K Padmanabhan ◽  
...  
Keyword(s):  
Articular Chondrocytes ◽  
Symptomatic Relief ◽  
Cartilage Damage ◽  
Treatment Strategies ◽  
Standard Of Care ◽  
Cartilage Degeneration ◽  
Current Standard ◽  
Disease Modifying Drugs ◽  
Post Traumatic ◽  
Sulphated Glycosaminoglycans

Trauma to the knee joint is associated with significant cartilage degeneration and erosion of subchondral bone, which eventually leads to osteoarthritis (OA), resulting in substantial morbidity and healthcare burden. With no disease-modifying drugs in clinics, the current standard of care focuses on symptomatic relief and viscosupplementation. Modulation of autophagy and targeting senescence pathways are emerging as potential treatment strategies. Rapamycin has shown promise in OA disease amelioration by autophagy upregulation, yet its clinical use is hindered by difficulties in achieving therapeutic concentrations, necessitating multiple weekly injections. Here, we have synthesized rapamycin - loaded poly (lactic-co-glycolic acid) microparticles (RMPs) that induced autophagy, prevented senescence and sustained sulphated glycosaminoglycans(sGAG) production in primary human articular chondrocytes from OA patients. RMPs were potent, nontoxic, and exhibited high retention time (up to 35 days) in mice joints. Intra-articular delivery of RMPs effectively mitigated cartilage damage and inflammation in surgery-induced OA when administered as a prophylactic or therapeutic regimen. Together, our studies demonstrate the feasibility of using RMPs as a potential clinically translatable therapy to prevent and treat post-traumatic osteoarthritis.

scholarly journals PKR Promotes Oxidative Stress and Apoptosis of Human Articular Chondrocytes by Causing Mitochondrial Dysfunction through p38 MAPK Activation—PKR Activation Causes Apoptosis in Human Chondrocytes

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 370 ◽  
Author(s):  
Ching-Hou Ma ◽  
Chin-Hsien Wu ◽  
I-Ming Jou ◽  
Yuan-Kun Tu ◽  
Ching-Hsia Hung ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
P38 Mapk ◽  
Articular Chondrocytes ◽  
Cartilage Degeneration ◽  
The Elderly ◽  
Human Articular Chondrocytes ◽  
Poly I:C ◽  
Chondrocyte Apoptosis ◽  
Tnf Α

Osteoarthritis (OA) is one of the most common types of arthritis in the elderly people. It has been known that chondrocyte apoptosis occurs in OA cartilage; however, the detailed molecular mechanism remains unclear. In the current study, we aimed to elucidate the role of double-stranded RNA-dependent protein kinase R (PKR) in the TNF-α-caused apoptosis in chondrocytes. Human articular chondrocytes were digested from cartilages of OA subjects who accepted arthroplastic knee surgery. Our results showed that phosphorylation of p38 MAPK was increased after TNF-α stimulation or PKR activation using poly (I:C), and TNF-α-induced p38 MAPK upregulation was inhibited by PKR inhibition, suggesting phosphor-p38 MAPK was regulated by PKR. Moreover, we found that PKR participated in the p53-dependent destruction of AKT following activation of p38 MAPK. The inhibition of AKT led to the reduced expression of PGC-1α, which resulted in mitochondrial dysfunction and increased oxidative stress. We showed that the reduction of oxidative stress using antioxidant Mito TEMPO lowered the TNF-α-induced caspase-3 activation and TUNEL-positive apoptotic cells. The diminished apoptotic response was also observed after repression of PKR/p38 MAPK/p53/AKT/PGC-1α signaling. Taken together, we demonstrated that the aberrant mitochondrial biogenesis and increased oxidative stress in chondrocytes after TNF-α stimulation were mediated by PKR, which may contribute to the chondrocyte apoptosis and cartilage degeneration in OA.

scholarly journals Cinnamic Acid (CINN) Induces Apoptosis and Proliferation in Human Nasopharyngeal Carcinoma Cells

2016 ◽  
Vol 40 (3-4) ◽  
pp. 589-596 ◽  
Author(s):  
Guangying Qi ◽  
Jian Chen ◽  
Changrong Shi ◽  
Yukun Wang ◽  
Sisi Mi ◽  
...  
Keyword(s):  
Protein Expression ◽  
Molecular Mechanisms ◽  
Flow Cytometric Analysis ◽  
D1 Protein ◽  
Inhibitory Effect ◽  
Flow Cytometric ◽  
Proliferation And Apoptosis ◽  
Dependent Flow ◽  
Fas L ◽  
Related Proteins

Background/Aims: CINN is the main ingredient of the traditional Chinese medicine cinnamon. The purpose of the present study was to investigate the effects of CINN on the proliferation and apoptosis of NPC cells and to elucidate the underlying molecular mechanisms. Materials and Methods: CNE2 human NPC cells were treated with various CINN concentrations. The effects of CINN on the proliferation and apoptosis of CNE2 NPC cells were examined using the MTT assay and flow cytometric analysis. Additionally, western blotting was performed to analyze the expression of a number of cell cycle- and apoptosis-related proteins. Results: The proliferation of CNE2 cells was significantly inhibited after treatment with different CINN concentrations for various lengths of time. The inhibitory effect of CINN was concentration-and time-dependent. Flow cytometric analysis showed that 2 mmol/L CINN displayed a significant apoptosis-inducing effect. The western blot analysis results showed that KLF6, Fas-L, Bax, P53 and caspase-3 protein expression was drastically increased in the CNE2 cells after treatment with 2 mmol/L CINN, whereas Bcl-2 and cyclin D1 protein expression was markedly reduced. Conclusion: CINN inhibits the proliferation and induces the apoptosis of CNE2 cells. Therefore, CINN possesses a potential anti-tumor effect.

scholarly journals Calcium calmodulin kinase II activity is required for cartilage homeostasis in osteoarthritis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Giovanna Nalesso ◽  
Anne-Sophie Thorup ◽  
Suzanne Elizabeth Eldridge ◽  
Anna De Palma ◽  
Amanpreet Kaur ◽  
...  
Keyword(s):  
Medial Meniscus ◽  
Articular Chondrocytes ◽  
Interleukin 1 ◽  
Cartilage Damage ◽  
Regenerative Processes ◽  
Cartilage Homeostasis ◽  
Calmodulin Kinase ◽  
Wnt Ligands ◽  
Pharmacological Blockade

AbstractWNT ligands can activate several signalling cascades of pivotal importance during development and regenerative processes. Their de-regulation has been associated with the onset of different diseases. Here we investigated the role of the WNT/Calcium Calmodulin Kinase II (CaMKII) pathway in osteoarthritis. We identified Heme Oxygenase I (HMOX1) and Sox-9 as specific markers of the WNT/CaMKII signalling in articular chondrocytes through a microarray analysis. We showed that the expression of the activated form of CaMKII, phospho-CaMKII, was increased in human and murine osteoarthritis and the expression of HMOX1 was accordingly reduced, demonstrating the activation of the pathway during disease progression. To elucidate its function, we administered the CaMKII inhibitor KN93 to mice in which osteoarthritis was induced by resection of the anterior horn of the medial meniscus and of the medial collateral ligament in the knee joint. Pharmacological blockade of CaMKII exacerbated cartilage damage and bone remodelling. Finally, we showed that CaMKII inhibition in articular chondrocytes upregulated the expression of matrix remodelling enzymes alone and in combination with Interleukin 1. These results suggest an important homeostatic role of the WNT/CaMKII signalling in osteoarthritis which could be exploited in the future for therapeutic purposes.

scholarly journals Upregulation of P2Y12 Inhibits Chondrocyte Apoptosis in Lumbar Osteoarthritis Through PI3K/AKT Signaling Pathway

2021 ◽  
Author(s):  
Guanyin Wu ◽  
Pengfei Xue ◽  
Mo Zhang ◽  
Chao Gui ◽  
Guofeng Bao ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Gene Knockout ◽  
Cartilage Degeneration ◽  
Underlying Mechanism ◽  
Chondrocyte Apoptosis ◽  
Low Back ◽  
Role Changes ◽  
Apoptotic Effect ◽  
Lumbar Facet

Abstract Lumbar facet osteoarthritis (FJOA) is one of the major causes of severe low back pain and disability worldwide. However, the underlying mechanism of cartilage degeneration in FJOA remains unclear. The purpose of this study was to investigate the expression of P2Y12 in FJOA and its possible role. Changes of chondrocytes in rat facet joints with degenerative changes were observed by HE and ferro red solid green staining. The expression changes of P2Y12, MMP13 and COL2 in FJOA were observed by immunohistochemistry. In vitro, human SW1353 chondrosarcoma cells were stimulated with IL-β to establish chondrocyte apoptosis model. Western blot analysis showed that P2Y12 and cleaved caspase-3 were significantly expressed in SW1353 cells. Co-localization of P2Y12-cleaved Caspase-3 in apoptosis model was detected by double-standard immunofluorescence staining. We demonstrated that P2Y12 may have an anti-apoptotic effect in FJOA chondrocytes apoptosis by inhibiting the expression of P2Y12 by siRNA. In addition, flow cytometry showed that P2Y12 gene knockout enhanced apoptosis induced by P2Y12. Our data suggest that P2Y12 has a chondroprotective effect on FJOA.

scholarly journals Hypoxia-inducible Factor Expression Is Related to Apoptosis and Cartilage Degradation in Temporomandibular Joint Osteoarthritis

2022 ◽  
Author(s):  
Jun Zhang ◽  
Yu Hu ◽  
Zihan Wang ◽  
Xuelian Wu ◽  
Chun Yang ◽  
...  
Keyword(s):  
Temporomandibular Joint ◽  
Expression Patterns ◽  
Cartilage Damage ◽  
Hypoxia Inducible Factor ◽  
Cartilage Degeneration ◽  
Chondrocyte Apoptosis ◽  
Control Group ◽  
Condylar Cartilage ◽  
Hypoxic Conditions ◽  
Temporomandibular Joint Osteoarthritis

Abstract Background: It remains unclear whether hypoxic conditions affect apoptosis and contribute to degradation of cartilaginous tissues in osteoarthritis (OA) lesions. In this study, we hypothesized that hypoxic conditions induced the accumulation of hypoxia-inducible factor (HIF) and activated apoptosis to contribute to OA cartilage degeneration in vivo.Methods: Malocclusion stress was applied for 2 weeks, 4 weeks and 8 weeks to induce an OA-like lesion animal model (OD) in rats. Histological analysis was performed by H&E staining and safranin O/fast green staining. The expression levels of protein in condylar cartilage were examined by immunostaining to evaluate cartilage degeneration.Results: We found apparent histological phenotypes associated with degeneration in the occlusion disorder stress (OD) group. The OD group at 4 weeks and 8 weeks had obviously reduced expression of Acan and Col II in cartilage. In contrast, the OD groups had higher levels of Col X, ADAMTS5 and MMP13 in the condylar cartilage than the control group. Moreover, the OD group cartilage had prominent degenerative changes with reduced levels of HIF1α and increased levels of HIF2α and the apoptosis factor Caspase3 in condylar cartilage at 8 weeks.Occlusion disorder stress results in cartilage degeneration. HIF1α and HIF2α are involved in temporomandibular joint (TMJ) cartilage homeostasis by regulating chondrocyte apoptosis, which contributes to TMJ cartilage degeneration. Conclusion: Thus, abnormal hypoxic conditions inducing opposite expression patterns of HIF1α and HIF2α could be involved in the pathogenesis of condylar cartilage degeneration. HIF2α may provide a potential negative feedback mechanism for HIF1α during cartilage damage.

Differential roles of nitric oxide and oxygen radicals in chondrocytes affected by osteoarthritis and rheumatoid arthritis

2001 ◽  
Vol 101 (6) ◽  
pp. 593-599 ◽  
Author(s):  
Ilaria MAZZETTI ◽  
Brunella GRIGOLO ◽  
Lia PULSATELLI ◽  
Paolo DOLZANI ◽  
Tania SILVESTRI ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Nitric Oxide ◽  
Superoxide Dismutase ◽  
Articular Chondrocytes ◽  
Interleukin 1 ◽  
Cartilage Damage ◽  
Organ Donors ◽  
Oxygen Species ◽  
Radical Oxygen Species ◽  
Oxygen Intermediates

Osteoarthritis and rheumatoid arthritis are characterized by focal loss of cartilage due to an up-regulation of catabolic pathways, induced mainly by pro-inflammatory cytokines, such as interleukin-1 (IL-1) and tumour necrosis factor α (TNFα). Since reactive oxygen species are also involved in this extracellular-matrix-degrading activity, we aimed to compare the chondrocyte oxidative status responsible for cartilage damage occurring in primarily degenerative (osteoarthritis) and inflammatory (rheumatoid arthritis) joint diseases. Human articular chondrocytes were isolated from patients with osteoarthritis or rheumatoid arthritis, or from multi-organ donors, and stimulated with IL-1β and/or TNFα. We evaluated the oxidative stress related to reactive nitrogen and oxygen intermediates, measuring NO2- as a stable end-product of nitric oxide generation and superoxide dismutase as an antioxidant enzyme induced by radical oxygen species. We found that cells from patients with osteoarthritis produced higher levels of NO2- than those from patients with rheumatoid arthritis. In addition, IL-1β was more potent than TNFα in inducing nitric oxide in both arthritides, and TNFα alone was almost ineffective in cells from rheumatoid arthritis patients. We also observed that the intracellular content of copper/zinc superoxide dismutase (Cu/ZnSOD) was always lower in rheumatoid arthritis chondrocytes than in those from multi-organ donors, whereas no differences were found in intracellular manganese SOD (MnSOD) or in supernatant Cu/ZnSOD and MnSOD levels. Moreover, intracellular MnSOD was up-regulated by cytokines in osteoarthritis chondrocytes. In conclusion, our results suggest that nitric oxide may play a major role in altering chondrocyte functions in osteoarthritis, whereas the harmful effects of radical oxygen species are more evident in chondrocytes from patients with rheumatoid arthritis, due to an oxidant/antioxidant imbalance.

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