Bauhinia championi (Benth.) Benth. polysaccharides upregulate Wnt/β-catenin signaling in chondrocytes

et al. 2014

Self Cite

Achyranthes bidentata polysaccharides (ABPS) are the active components of Radix Achyranthis Bidentatae (AB), which has been extensively used in Traditional Chinese medicine (TCM) in the treatment of osteoarthritis (OA). Our previous study provided evidence that ABPS regulated the G1/S transition to promote chondrocyte proliferation. However, the precise mechanisms involved remain to be elucidated. In the present study, we aimed to investigate the effects of ABPS on the Wnt/β‑catenin signaling pathway in chondrocytes. Chondrocytes, obtained from the knee cartilage of Sprague-Dawley rats, were identified by type II collagen immunohistochemistry. ABPS upregulated the expression of Wnt-4, Frizzled-2, β-catenin and cyclin D1, and downregulated the expression of glycogen synthase kinase 3β (GSK-3β), as shown by reverse transcription PCR (RT-PCR) and western blot analysis. Using immunofluorescence, we also found that ABPS induced β-catenin nuclear translocation. Importantly, the expression of β-catenin and cyclin D1 was partly inhibited by Dickkopf-1 (DKK-1), an inhibitor of the Wnt/β-catenin signaling pathway. In addition, we found that ABPS increased the expression of type II collagen in chondrocytes. These results suggest that ABPS promote chondrocyte proliferation by activating the Wnt/β-catenin signaling pathway.

Section: Methodsmentioning

confidence: 99%

Achyranthes bidentata polysaccharides activate the Wnt/β-catenin signaling pathway to promote chondrocyte proliferation

Weng

Lin

et al. 2014

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“…The chondrocyte morphology was as described previously ( Fig. 1) (16,17). Newly-isolated chondrocytes were known as passage 0 (P0).…”

Section: Resultsmentioning

confidence: 99%

Duhuo Jisheng decoction treatment inhibits the sodium nitroprussiate-induced apoptosis of chondrocytes through the mitochondrial-dependent signaling pathway

Liang

et al. 2014

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Chondrocyte apoptosis activated by the mitochondrial-dependent signaling pathway plays a crucial role in the cartilage degeneration of osteoarthritis. Duhuo Jisheng decoction (DHJSD), a herbal formula from traditional Chinese medicine, has been widely used for treating osteoarthritis (OA). However, the molecular mechanisms behind the therapeutic effect of DHJSD remain to be elucidated. In the present study, the effects of DHJSD on the mitochondrial-dependent signaling pathway in sodium nitroprussiate (SNP)-induced chondrocyte apoptosis were investigated. Chondrocytes, from the knee articular cartilage of Sprague Dawley rats, were identified by type II collagen immunohistochemistry. The chondrocytes, stimulated with or without SNP to induce apoptosis, were treated by DHJSD for various concentrations and times. The viability of SNP-induced chondrocytes treated with DHJSD was enhanced compared to SNP-induced chondrocytes in a dose- and time-dependent manner, as assessed by the MTT assay. The apoptosis of SNP-induced chondrocytes treated by DHJSD was significantly decreased compared to SNP-induced chondrocyte, as shown by 4',6-diamidino-2-phenylindole and Annexin V/propidium iodide staining. The mitochondrial membrane potential (∆Ψm) of SNP-induced chondrocytes treated by DHJSD was significantly decreased compared to SNP-induced chondrocyte, as shown by JC-1 staining. To understand the mechanism, the mRNA and protein levels of Bax, B-cell lymphoma 2 (Bcl-2), caspase-9 and caspase-3 were detected by reverse transcription‑polymerase chain reaction and western blot analysis, respectively. In SNP-induced chondrocyte treated by DHJSD, the Bcl-2 expression was increased, whereas the expression of Bax, caspase-9 and caspase-3 was decreased compared to SNP-induced chondrocyte. Taken together, these results indicated that DHJSD inhibits the apoptosis of SNP-induced chondrocyte by the mitochondrial-dependent apoptotic pathway, and this may partly explain its therapeutic efficacy for OA.

“…Male Sprague-Dawley rats (4-week-old) were from Super-BK Laboratory Animal Co. (Shanghai, China). Chondrocytes were isolated from articular cartilage and cultured as previously described (17). The second-passage (P2) chondrocytes cultured until ~80% confluency were used in the study.…”

Section: Isolation Identification and Treatment Of Chondrocytesmentioning

confidence: 99%

“…The morphology of newly isolated chondrocytes was small, round and floating in the medium, and after a few days culture, chondrocytes were connected during growth and showed an irregular paving stone shape with clear boundaries and distinct nuclei (17,19,20) (Fig. 2).…”

Section: Morphology and Identification Of Chondrocytesmentioning

confidence: 99%

Duhuo Jisheng decoction inhibits endoplasmic reticulum stress in chondrocytes induced by tunicamycin through the downregulation of miR-34a

Weng

Lin

et al. 2015

Self Cite

Abstract. Our previous study showed that Duhuo Jisheng decoction (DHJSD) inhibited chondrocyte apoptosis by the mitochondria-dependent signaling pathway. Endoplasmic reticulum (ER) stress is upstream of the mitochondria-dependent signaling pathway and has been shown to promote chondrocyte apoptosis that occurs in osteoarthritis (OA). The present study aimed to evaluate whether DHJSD inhibits the chondrocyte apoptosis by regulating ER stress. DHJSD enhanced the viability of tunicamycin (TM)-exposed chondrocytes, a model of ER stress-induced apoptosis, in a dose-and time-dependent manner, as shown by MTT assay. The present results showed that DHJSD and sodium 4-phenylbutyrate (PBA), an ER stress inhibitor, reduced TM-induced chondrocyte apoptosis by 4' ,6-diamidino-2-phenylindole staining. To gain insight into the mechanisms of DHJSD that are responsible for enhancing the viability and inhibiting TM-induced chondrocyte apoptosis, the associated mRNA expressions and protein levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis, respectively. The results showed that the expression levels of Xbp1, Xbp1s and Bcl-2 were increased, and the expression levels of Bip, Atf4, Chop, Bax, caspase-9 and -3 were decreased in the TM-exposed chondrocytes treated with DHJSD or PBA compared with that in the TM-exposed chondrocytes. To identify the possible mechanisms, the expression of miR-34a was examined by the TaqMan microRNA assay, and was downregulated in the TM-exposed chondrocytes treated with DHJSD or PBA compared with that in the TM-exposed chondrocytes. DHJSD inhibits ER stress in chondrocytes induced by exposure to TM by downregulating miR-34a, suggesting that DHJSD may be a potential therapeutic agent for OA.