scholarly journals Inhibitory Effect of Curcumol on Jak2-STAT Signal Pathway Molecules of Fibroblast-Like Synoviocytes in Patients with Rheumatoid Arthritis

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Heng Wang ◽  
Yongfei Fang ◽  
Yong Wang ◽  
Zhizhong Wang ◽  
Qinghua Zou ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Cell Proliferation ◽  
Dna Binding ◽  
Dna Synthesis ◽  
Synovial Membrane ◽  
Signal Pathway ◽  
Janus Kinase ◽  
Protein Expressions ◽  
Fibroblast Like Synoviocytes

Hyperplasia of synovial membrane in rheumatoid arthritis (RA) is a critical pathological foundation for inducing articular injury. The janus kinase and signal transducer and activator of transcription (Jak-STAT) pathway plays a critical role in synovial membrane proliferation induced by platelet-derived growth factor (PDGF). To explore the anti-cell proliferation mechanism of curcumol, a pure monomer extracted from Chinese medical plantzedoary rhizome, the changes of Jak2-STAT1/3 signal pathway-related molecules in synoviocytes were observedin vitro. In this study, the fibroblast-like synoviocytes (FLS) in patients with RA were collected and cultured. The following parameters were measured: cell proliferation (WST-1 assay), cell cycles (fluorescence-activated cell sorting, FACS), STAT1 and STAT3 activities (electrophoretic mobility shift assay, EMSA), and the protein expressions of phosphorylated Jak2, STAT1, and STAT3 (Western blot). It was shown that curcumol could inhibit the RA-FLS proliferation and DNA synthesis induced by PDGF-BB in a dose-dependent mannerin vitro. The transcription factors activities of STAT1 and STAT3 were obviously elevated after PDGF-BB stimulation (P<0.05). Super-shift experiments identified the STAT1 or STAT3 proteins in the complex. Furthermore, the different concentration curcumol could downregulate the DNA binding activities of STAT1 and STAT3 (P<0.05) and inhibit the phosphorylation of Jak2 while it had no effect on the protein expressions of STAT1 and STAT3. Positive correlations were found between changes of cell proliferation and DNA-binding activities of STAT1 and STAT3, respectively (P<0.01). In conclusion, curcumol might suppress the FLS proliferation and DNA synthesis induced by PDGF-BB through attenuating Jak2 phosphorylation, downregulating STAT1 and STAT3 DNA-binding activities, which could provide theoretical foundation for clinical treatment of RA.

scholarly journals P460 Evaluation of potential mechanisms underlying the safety observations of filgotinib in clinical studies in rheumatoid arthritis

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S409-S409
Author(s):  
A Clarke ◽  
J Di Paolo ◽  
B Downie ◽  
A Meng ◽  
N Mollova ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Cell Proliferation ◽  
Clinical Studies ◽  
Nk Cell ◽  
Janus Kinase ◽  
Jak Inhibitor ◽  
Jak Inhibitors ◽  
Erythroid Progenitor ◽  
Cell Counts

Abstract Background Inhibitors of the Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway have demonstrated efficacy in the treatment of rheumatoid arthritis (RA) and inflammatory bowel disease (IBD). Differences in selectivity of JAK inhibitors for JAK1, JAK2, JAK3 and TYK2 may influence their respective safety profiles, and the mechanisms responsible are not currently known. Filgotinib (FIL), a JAK1 inhibitor, did not negatively impact haemoglobin, LDL:HDL ratios or natural killer (NK) cell counts in clinical trials. Here, we compare the in vitro mechanistic profiles of four JAK inhibitors at clinically relevant doses. Methods JAK inhibitors (FIL, FIL metabolite [GS-829845], baricitinib [BARI], tofacitinib [TOFA], and upadacitinib [UPA]) were evaluated in vitro in human-cell-based assays. Growth of erythroid progenitors from human cord blood CD34+ cells was assessed using a HemaTox™ liquid expansion assay, NK cell proliferation was induced by IL-15 and LXR agonist-induced cholesteryl ester transfer protein (CETP) expression was assessed in the hepatic cell line, HepG2. Using assay-generated IC50 values and the reported human plasma concentrations from clinical studies, we calculated the target coverage for each JAK inhibitor at clinically relevant doses. The activity of FIL in humans was based on PK/PD modelling of FIL + GS-829845. Results Inhibition of cellular activity was calculated for each JAK inhibitor based on in vitro dose-response data, human exposure data and modelled PK/PD relationships. At clinically relevant doses, FIL resulted in lower calculated inhibition of NK cell proliferation compared with other JAK inhibitors. FIL 100 mg and 200 mg also reduced CETP expression, whereas other JAK inhibitors had no effect. There was no difference in the effect of FIL vs. other JAK inhibitors on erythroid progenitor cell differentiation or maturation. Conclusion FIL, a JAK1 inhibitor, resulted in less inhibition of NK cell proliferation compared with BARI, TOFA, and UPA. FIL also reduced LXR agonist-induced CETP expression, while the other inhibitors did not alter these levels. These results provide a potential mechanistic link between the observed reduction of CETP concentration following FIL treatment and the previously observed reduction in the LDL:HDL ratio in RA patients.

scholarly journals Insulin Stimulates Goose Liver Cell Growth by Activating PI3K-AKT-mTOR Signal Pathway

2016 ◽  
Vol 38 (2) ◽  
pp. 558-570 ◽  
Author(s):  
Chunchun Han ◽  
Shouhai Wei ◽  
Qi Song ◽  
Fang He ◽  
Xiangping Xiong ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Synthesis ◽  
Protein Content ◽  
Mrna Level ◽  
Signal Pathway ◽  
Mtor Pathway ◽  
Brdu Incorporation ◽  
Primary Hepatocytes

Background/Aims: Recent studies have suggested a crucial role for PI3K-Akt-mTOR pathway in regulating cell proliferation, so we hypothesize that insulin acts goose hepatocellular growth by PI3K-Akt-mTOR signal pathway. Because the physiological status of liver cells in vitro is different from that in vivo, a simplified cell model in vitro was established. Methods: Goose primary hepatocytes were isolated and incubated in either no addition as a control or insulin or PI3K-Akt-mTOR pathway inhibitors or co-treatment with glucose and PI3K-Akt-mTOR pathway inhibitors; Then, cell DNA synthesis and cell cycle analysis were detected by BrdU-incorporation Assay and Flow cytometric analysis; the mRNA expression and protein expression of factors involved in the cell cycle were determined by Real-Time RT-PCR, ELISA, and western blot. Results: Here we first showed that insulin evidently increased the cell DNA synthesis, the mRNA level and protein content of factors involved in the cell proliferation of goose primary hepatocytes. Meanwhile, insulin evidently increased the mRNA level and protein content of factors involved in PI3K-Akt-mTOR pathway. However, the up-regulation of insulin on cell proliferation was decreased significantly by the inhibitors of PBK-Akt-mTOR pathway, LY294002, rapamycin or NVP-BEZ235. Conclusion: These findings suggest that PI3K-Akt-mTOR pathway plays an essential role in insulin-regulated cell proliferation of goose hepatocyte.

MicroRNA-16-5p Promoted Fibroblast-Like Synoviocyte Proliferation and Suppressed Apoptosis via Targeting Suppressor of Cytokine Signaling 6 (SOCS6) in Human Rheumatoid Arthritis

2021 ◽  
Vol 11 (9) ◽  
pp. 1744-1751
Author(s):  
Deqian Meng ◽  
Wenyou Pan ◽  
Ju Li
Keyword(s):  
Rheumatoid Arthritis ◽  
Cell Proliferation ◽  
Luciferase Reporter Assay ◽  
Luciferase Reporter ◽  
Cytokine Signaling ◽  
Human Rheumatoid Arthritis ◽  
Reporter Assay ◽  
Functional Roles ◽  
Proliferation And Apoptosis ◽  
Fibroblast Like Synoviocytes

Accumulating evidence have indicated that MicroRNAs (miRNAs) are key regulators in human rheumatoid arthritis (RA). The aim of this study was to explore the functional roles of miR-16-5p in proliferation, inflammation, and apoptosis of fibroblast-like synoviocytes (FLS). The expression of miR-16-5p and SOCS6 in FLA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation and apoptosis were measured by CCK-8 assay and flow cytometry, respectively. Luciferase reporter assay was used to verify the direct target of miR-16-5p. Western blot analysis was performed to analysis the levels of SOCS6, Bcl-2, Bax and cleaved caspase 3. miR-16-5p expression was significantly upregulated while SOCS6 level was decreased in RA-FLS compared with normal FLS. In addition, luciferase reporter assay confirmed that SOCS6 was the target of miR-16-5p. Silencing of miR-16-5p inhibited cell proliferation, releases of TNF-α, IL-1β, IL-6 and IL-8, and induced the apoptosis. The effects of miR-16-5p silencing on RA-FLS were reversed by downregulation of SOCS6. In summary, knockdown of miR-16-5p could suppress cell proliferation and accelerate the apoptosis of RA-FLS through targeting SOCS6, which may provide a potential therapeutic target for patients with RA.

scholarly journals Binding of a sequence-specific single-stranded DNA-binding factor to the simian virus 40 core origin inverted repeat domain is cell cycle regulated.

1993 ◽  
Vol 13 (1) ◽  
pp. 408-420 ◽  
Author(s):  
E P Carmichael ◽  
J M Roome ◽  
A F Wahl
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Binding ◽  
Dna Synthesis ◽  
Inverted Repeat ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Single Stranded Dna ◽  
Repeat Domain

The inverted repeat domain (IR domain) within the simian virus 40 origin of replication is the site of initial DNA melting prior to the onset of DNA synthesis. The domain had previously been shown to be bound by a cellular factor in response to DNA damage. We demonstrate that two distinct cellular components bind opposite strands of the IR domain. Replication protein A (RPA), previously identified as a single-stranded DNA binding protein required for origin-specific DNA replication in vitro, is shown to have a preference for the pyrimidine-rich strand. A newly described component, IR factor B (IRF-B), specifically recognizes the opposite strand. IRF-B binding activity in nuclear extract varies significantly with cell proliferation and the cell cycle, so that binding of IRF-B to the IR domain is negatively correlated with the onset of DNA synthesis. Loss of IRF-B binding from the nucleus also occurs in response to cellular DNA damage. UV cross-linking indicates that the core binding component of IRF-B is a protein of ca. 34 kDa. We propose that RPA and IRF-B bind opposite strands of the IR domain and together may function in the regulation of origin activation.

scholarly journals Tofacitinib Suppresses Several JAK-STAT Pathways in Rheumatoid Arthritis In Vivo and Baseline Signaling Profile Associates With Treatment Response

2021 ◽  
Vol 12 ◽  
Author(s):  
Maaria Palmroth ◽  
Krista Kuuliala ◽  
Ritva Peltomaa ◽  
Anniina Virtanen ◽  
Antti Kuuliala ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
T Cells ◽  
Treatment Response ◽  
Peripheral Blood ◽  
Janus Kinase ◽  
Cytokine Signaling ◽  
Stat3 Phosphorylation ◽  
Stat Pathway

ObjectiveCurrent knowledge on the actions of tofacitinib on cytokine signaling pathways in rheumatoid arthritis (RA) is based on in vitro studies. Our study is the first to examine the effects of tofacitinib treatment on Janus kinase (JAK) - signal transducer and activator of transcription (STAT) pathways in vivo in patients with RA.MethodsSixteen patients with active RA, despite treatment with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), received tofacitinib 5 mg twice daily for three months. Levels of constitutive and cytokine-induced phosphorylated STATs in peripheral blood monocytes, T cells and B cells were measured by flow cytometry at baseline and three-month visits. mRNA expression of JAKs, STATs and suppressors of cytokine signaling (SOCS) were measured from peripheral blood mononuclear cells (PBMCs) by quantitative PCR. Association of baseline signaling profile with treatment response was also investigated.ResultsTofacitinib, in csDMARDs background, decreased median disease activity score (DAS28) from 4.4 to 2.6 (p &lt; 0.001). Tofacitinib treatment significantly decreased cytokine-induced phosphorylation of all JAK-STAT pathways studied. However, the magnitude of the inhibitory effect depended on the cytokine and cell type studied, varying from 10% to 73% inhibition following 3-month treatment with tofacitinib. In general, strongest inhibition by tofacitinib was observed with STAT phosphorylations induced by cytokines signaling through the common-γ-chain cytokine receptor in T cells, while lowest inhibition was demonstrated for IL-10 -induced STAT3 phosphorylation in monocytes. Constitutive STAT1, STAT3, STAT4 and STAT5 phosphorylation in monocytes and/or T cells was also downregulated by tofacitinib. Tofacitinib treatment downregulated the expression of several JAK-STAT pathway components in PBMCs, SOCSs showing the strongest downregulation. Baseline STAT phosphorylation levels in T cells and monocytes and SOCS3 expression in PBMCs correlated with treatment response.ConclusionsTofacitinib suppresses multiple JAK-STAT pathways in cytokine and cell population specific manner in RA patients in vivo. Besides directly inhibiting JAK activation, tofacitinib downregulates the expression of JAK-STAT pathway components. This may modulate the effects of tofacitinib on JAK-STAT pathway activation in vivo and explain some of the differential findings between the current study and previous in vitro studies. Finally, baseline immunological markers associate with the treatment response to tofacitinib.

scholarly journals Apoptosis Induction of Fibroblast-Like Synoviocytes Is an Important Molecular-Mechanism for Herbal Medicine along with its Active Components in Treating Rheumatoid Arthritis

Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 795 ◽  
Author(s):  
Qing Zhang ◽  
Jia Liu ◽  
Mengmeng Zhang ◽  
Shujun Wei ◽  
Ruolan Li ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Molecular Mechanisms ◽  
Herbal Medicines ◽  
Janus Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Signal Pathways ◽  
Apoptosis Induction ◽  
Apoptotic Pathway ◽  
Induction Of Apoptosis ◽  
Fibroblast Like Synoviocytes

Rheumatoid arthritis (RA) is a known chronic autoimmune disease can cause joint deformity and even loss of joint function. Fibroblast-like synoviocytes (FLS), one of the main cell types in synovial tissues of RA patients, are key effector cells in the development of RA and are considered as promising therapeutic targets for treating RA. Herbal medicines are precious resources for finding novel agents for treating various diseases including RA. It is reported that induction of apoptosis in FLS is an important mechanism for the herbal medicines to treat RA. Consequently, this paper reviewed the current available references on pro-apoptotic effects of herbal medicines on FLS and summarized the related possible signal pathways. Taken together, the main related signal pathways are concluded as death receptors mediated apoptotic pathway, mitochondrial dependent apoptotic pathway, NF-κB mediated apoptotic pathways, mitogen-activated protein kinase (MAPK) mediated apoptotic pathway, endoplasmic reticulum stress (ERS) mediated apoptotic pathway, PI3K-Akt mediated apoptotic pathway, and other reported pathways such as janus kinase/signal transducers and activators of transcription (JAK-STAT) signal pathway. Understanding the apoptosis induction pathways in FLS of these herbal medicines will not only help clear molecular mechanisms of herbal medicines for treating RA but also be beneficial for finding novel candidate therapeutic drugs from natural herbal medicines. Thus, we expect the present review will highlight the importance of herbal medicines and its components for treating RA via induction of apoptosis in FLS, and provide some directions for the future development of these mentioned herbal medicines as anti-RA drugs in clinical.

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