Piceatannol suppresses inflammation and promotes apoptosis in rheumatoid arthritis­fibroblast­like synoviocytes by inhibiting the NF­κB and MAPK signaling pathways.

Rheumatoid arthritis (RA) is a chronic inflammatory disease that mainly targets the synovial membrane, thus causing stiffness, deformity and dysfunction of joints. To date, no effective anti­inflammatory treatments are available for RA. Piceatannol (PIC) is a natural derivative of resveratrol, which has been reported to attenuate the inflammatory response. To evaluate the effect of PIC on RA and to determine the underlying molecular target of PIC, both in vitro and in vivo experiments were performed in the present study. A CIA rat model was established to evaluate the therapeutic effects of PIC. TNF­α, IL­1ß and IL­6 levels in blood were measured by ELISA. Western blotting, immunofluorescence analysis and reverse transcription­quantitative PCR (RT­qPCR) were used to analyze the expression levels of protein and mRNA. In vitro, RA­fibroblast­like synoviocytes (FLSs) were pretreated with PIC and subsequently stimulated with TNF­α. The results revealed that PIC significantly upregulated the expression levels of proapoptotic proteins such as Bax and cleaved caspase­3. PIC also significantly reduced the production of proinflammatory cytokines, including PGE2, IL­6 and IL­1ß, and significantly downregulated the expression of cyclooxygenase­2 at both the mRNA and protein expression levels. Furthermore, PIC downregulated the expression of MMP­3 and MMP­13, which have been found to be highly expressed in the synovium of patients with RA. Mechanistically, PIC was capable of significantly downregulating the expression levels of proteins involved in the NF­κB and MAPK signaling pathways. The results of the in vivo experiments using a rat collagen­induced arthritis model demonstrated that PIC decreased the arthritis score and exerted beneficial effects in cartilage and significantly reduced the expression of MMP­13. In conclusion, the findings of the present study revealed that PIC could suppress the inflammatory response, promote apoptosis, and exert a significant regulatory effect on the NF­κB and MAPK signaling pathways in RA­FLSs. Therefore, PIC may represent a potential drug for the future treatment of RA.

Hydrogen (H2) Alleviates Osteoarthritis by Inhibiting Apoptosis and Inflammation via the JNK Signaling Pathway.

BACKGROUND: Osteoarthritis (OA) is a very common condition and leads to joint pain, disability, and price tag all over the world. Pathogenesis of OA is closely related to numerous inflammatory and apoptosis cytokines. Hydrogen (H2) reportedly exhibits a diversity of effects such as anti-apoptotic, anti-inflammatory, and anti-oxidative properties via the JNK pathway. However, it is unknown whether H2 has a protective effect against OA via the JNK signaling pathway. Therefore, the aim of this study was to figure out whether hydrogen has protective effect on chondrocyte and further explore the possible underlying mechanism. METHODS: The chondrocytes were obtained from the human cartilage tissues. Cells were stimulated by TBHP and treated with hydrogen. In vitro treatment effects were evaluated by Western blot assay, real-time PCR, immunofluorescence and TUNEL method. We conducted mice model of destabilization of the medial meniscus (DMM) and treated with hydrogen. In vivo treatment effects were evaluated by X-ray imaging assay, safranin O (SO) staining, TUNEL staining and immunohistochemical assay. RESULTS: Our results showed that hydrogen can inhibit inflammatory factors (ADAMTS5 and MMP13) and apoptosis factors (cleaved caspase-3, cytochrome c, and Bax) in TBHP-induced chondrocytes. Furthermore, hydrogen can suppress the activation of JNK signaling pathway, whereas the effect of hydrogen can be abolished by anisomycin (a JNK activator). In vivo results showed that hydrogen can down-regulate the expression of p-JNK and cleaved caspase-3 expression. CONCLUSION: We uncovered that hydrogen (H2) could alleviate apoptosis response and ECM degradation in human chondrocytes via inhibiting the activation of the JNK signaling pathway. Meanwhile, in the surgically-induced DMM mice model, treatment with hydrogen (H2) performed a significant role in OA progression.

Hedgehog/GLI1 signaling pathway regulates the resistance to cisplatin in human osteosarcoma.

Purpose: This study aimed to investigate the role and mechanism of Hedgehog/GLI1 signaling pathway in regulating the resistance to cisplatin in osteosarcoma (OS). Materials and methods: Immunohistochemistry, western blotting and qRT-PCR assay were performed to analyze and compare the expression of GLI1 in OS tumor tissue and normal bone tissue as well as in cisplatin sensitive and resistant cell lines (SOSP-9607 and SOSP-9607/CR). Meanwhile, the biological role of GLI1 in OS was investigated by using down-regulated expression of GLI1 and functional assays, including CCK-8, colony formation assay, flow cytometry, and wound healing assay. Moreover, the relationship between GLI1 and γ-H2AX (DNA damage protein) in cells treated with GLI1 siRNA and cisplatin was examined using western blot analysis. In addition, GANT61, a inhibitor of Hedgehog pathway was used in xenograft tumor model to further verify the effect and mechanism of GLI1 on cisplatin resistance in OS. Results: We showed that GLI1 expression was up-regulated in OS patients and cisplatin-resistant cells. Silencing GLI1 significantly restored the sensitivity of OS to cisplatin, reduced proliferation, migration and cloning capacity of cisplatin sensitive and resistant cells, and increased the apoptosis rate in vitro. Furthermore, combined administration of GANT61 and cisplatin markedly inhibitted tumor growth in the mouse model. Mechanitic studies found that γ-H2AX is involved in the cisplatin resistance, and blockade of Hedgehog/GLI1 pathway increased the expression of γ-H2AX. Conclusion: Abnormal activation of Hedgehog-GLI1 pathway can regulate the expression of γ-H2AX, thus affecting DNA damage and repair functions, and promoting acquired cisplatin resistance of OS.

Efferocytosis and Its Associated Cytokines: A Light on Non-tumor and Tumor Diseases?

Billions of cells undergo turnover and die via apoptosis throughout our lifetime. A prompt clearance of these apoptotic cells and debris by phagocytic cells, a process known as efferocytosis, is important in maintaining tissue homeostasis. Accordingly, impaired efferocytosis due to the defective clearance and disrupted stages can lead to a growing number of inflammation- and immune-related diseases. Although numerous studies have shown the mechanisms of efferocytosis, its role in disorders, such as non-tumor and tumor diseases, remains poorly understood. This review summarizes the processes and signal molecules in efferocytosis, and efferocytosis-related functions in non-tumor (e.g., atherosclerosis, lung diseases) and tumor diseases (e.g., breast cancer, prostate cancer), as well as describes the role of involved cytokines. Of note, there is a dual role of efferocytosis in the abovementioned disorders, and a paradoxical effect among non-tumor and tumor diseases in terms of inflammation resolution, immune response, and disease progression. Briefly, intact efferocytosis and cytokines promote tissue repair, while they contribute to tumor progression via the tumor microenvironment and macrophage politzerization. Additionally, this review provides potential targets associated with TAM (TYRO3, AXL, MERTK) receptors and cytokines, such as tumor necrosis factor α and CXCL5, suggesting potential novel therapeutic ways in treating diseases.

Deciphering role of FGFR signalling pathway in pancreatic cancer.

Recently, fibroblast growth factors are identified to play a vital role in the development and progression of human pancreatic cancer. FGF pathway is critical involved in numerous cellular processes through regulation of its downstream targets, including proliferation, apoptosis, migration, invasion, angiogenesis and metastasis. In this review article, we describe recent advances of FGFR signalling pathway in pancreatic carcinogenesis and progression. Moreover, we highlight the available chemical inhibitors of FGFR pathway for potential treatment of pancreatic cancer. Furthermore, we discuss whether targeting FGFR pathway is a novel therapeutic strategy for pancreatic cancer clinical management.

Nobiletin Inhibits IL-1ß-Induced Inflammation in Chondrocytes via Suppression of NF-κB Signaling and Attenuates Osteoarthritis in Mice.

Osteoarthritis (OA), a common degenerative joint disease, is principally characterized by inflammation and destruction of cartilage. Nobiletin, an extract of the peel of citrus fruits, is known to have anti-inflammatory properties. However, the mechanisms by which nobiletin plays a protective role in osteoarthritis (OA) are not completely understood. In the present study, we investigated the anti-inflammatory effects of nobiletin in the progression of OA in both in vitro and in vivo experiments. Mouse chondrocytes were pretreated with nobiletin (0, 10, 20, 40 µM) for 24 h and then incubated with IL-1ß (10 ng/ml, 24 h) in vitro. The generation of PGE2 and NO was evaluated by the Griess reaction and ELISAs. The protein expression of inducible nitric oxide synthase, matrix metalloproteinase-3, matrix metalloproteinase-13, A disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS5), cyclooxygenase-2, collagen II, and aggrecan was analyzed by Western blotting. Immunofluorescence and Western blot analysis were used to detect nuclear factor-κB (NF-κB) signaling molecules. Induction of proinflammatory and catabolic mediators by IL-1ß stimulation of mouse chondrocytes could be partially blocked by treatment with nobiletin or ammonium pyrrolidine dithiocarbamate (an NF-κB inhibitor). Furthermore, our results indicated that nobiletin exhibited a therapeutic effect through active inhibition of the NF-κB signaling pathway. In a mouse model of OA, injection of nobiletin (20 mg/kg) every 2 days for 8 weeks after surgery inhibited cartilage destruction and synovitis. Taken together, our findings suggest that nobiletin may be a potential therapeutic agent for the treatment of OA.

The protective effect of sophocarpine in osteoarthritis: An in vitro and in vivo study.

BACKGROUND: Osteoarthritis (OA) is a type of degenerative joint disease affecting millions of individuals worldwide. However, there are currently no great inflammatory treatments available for it. Sophocarpine (SPC), one of the key bioactive compounds derived from Sophora flavescens, has shown remarkable anti-inflammatory effects. METHODS: In this study, we evaluated the effect of SPC on preventing the progression of OA and investigated its molecular target involved. In brief, rat chondrocytes were pretreated with SPC and subsequently stimulated with IL-1ß. We found that SPC reduced the production of pro-inflammatory cytokines, such as nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6). SPC also inhibited the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) at both the gene and protein level. Moreover, SPC promoted the expression of anabolic factors Sox-9 and aggrecan, while inhibiting the expression of catabolic factors, such as matrix metalloproteinases 13 (MMP-13) and thrombospondin motifs 5 (ADAMTS-5) in rat chondrocytes. Mechanistically, we found that SPC inhibited nuclear factor kappa B (NF-κB) via the phosphatidylinositol 3 kinase (PI3K)/AKT pathway. The beneficial effects of SPC were also observed in vivo using a rat OA model. CONCLUSIONS: Our findings indicate that SPC may be a potential novel therapeutic in the treatment of OA.

Sauchinone inhibits IL-1ß induced catabolism and hypertrophy in mouse chondrocytes to attenuate osteoarthritis via Nrf2/HO-1 and NF-κB pathways.

BACKGROUND: Osteoarthritis (OA) is a common degenerative joint disease for which currently no anti-inflammatory therapy is available. Sauchinone (SAU), a key bioactive compound derived from Saururus chinensis, which has shown remarkable anti-inflammatory effects. METHODS: To evaluate the effect of SAU on OA progression, mouse chondrocytes were pretreated with SAU and subsequently stimulated with interleukin (IL)-1ß. We found that SAU reduced the production of pro-inflammatory cytokines, such as nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and IL-6. SAU also inhibited the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) at both the gene and protein level. Moreover, SAU promoted the expression of aggrecan, while inhibiting the expression of catabolic factors, such as matrix metalloproteinases (MMPs) and thrombospondin motifs 5 (ADAMTS-5) in mouse chondrocytes. Col X, vascular endothelial growth factor-A (VEGF)-A, and Runx2, major markers of hypertrophic chondrocytes, were markedly elevated following IL-1ß stimulation, and were reduced by SAU treatment while having the opposite effect on Col II. Mechanistically, we found that SAU inhibited nuclear factor kappa B (NF-κB) and activated the Nrf2/HO-1 pathway. The beneficial effects of SAU were also observed in vivo using a mouse OA model. CONCLUSIONS: Our findings indicate that SAU may be a potential novel therapeutic for the treatment of OA.