Effects of Aqueous Extract of Sophora flavescens on the Expression of Cell Cycle Regulatory Proteins in Human Oral Mucosal Fibroblasts

2003 ◽  
Vol 31 (04) ◽  
pp. 563-572 ◽  
Author(s):  
Hyun-A Kim ◽  
Hyung-Keun You ◽  
Hyung-Shik Shin ◽  
Youn-Chul Kim ◽  
Tai-Hyun Kang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Progression ◽  
Cyclin E ◽  
Regulatory Proteins ◽  
Cyclin D ◽  
Sophora Flavescens ◽  
Cycle Progression ◽  
Cell Cycle Regulatory Proteins ◽  
Cycle Regulation

Sophorae Radix, the dried roots of Sophora flavescens AITON (Leguminosae), has been used in Oriental traditional medicine for treatment of skin and mucosal ulcers, sores, gastrointestinal hemorrhage, diarrhea, inflammation and arrhythmia. In the present study, we examine the effect of the aqueous extract of Sophorae Radix (AESR) on cell proliferation and cell cycle regulation in human oral mucosal fibroblasts (HOMFs). To study the molecular mechanisms of cell cycle regulation by AESR, we also measured the intracellular levels of cell cycle regulatory proteins such as cyclin D, cyclin-dependent kinases (CDK)-4, CDK-6, cyclin E, CDK-2, p53, p21WAF1/CIP1 and p16INK4 . Cell proliferation was increased in the presence of 10~500 μg/ml of AESR. Maximal growth stimulation was observed in those cells exposed to 100 μg/ml of AESR. Exposure of HOMFs to 100 μg/ml of AESR resulted in an increase of cell cycle progression. The levels of cyclin E and CDK-2 were increased in HOMFs after 100 μg/ml of AESR treatment, but the levels of cyclin D, CDK-4, and CDK-6 were unchanged. After exposure to 100 μg/ml of AESR, the protein levels of p16INK4A and p53 were decreased as compared to that of the control group, but the level of p21WAF1/CIP1 was similar in the cells treated with 100 μg/ml of AESR and untreated cells. The results suggest that AESR may increase cell proliferation and cell cycle progression in HOMFs, which is linked to increased cellular levels of cyclin E and CDK-2 and decreased cellular levels of p53 and p16INK4A . Further studies are necessary to clarify the active constituents of AESR responsible for such biomolecular activities.

scholarly journals p38 mitogen-activated protein kinase contributes to cell cycle regulation by cAMP in FRTL-5 thyroid cells

2005 ◽  
Vol 153 (1) ◽  
pp. 123-133 ◽  
Author(s):  
C Corrèze ◽  
J-P Blondeau ◽  
M Pomérance
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Cyclin E ◽  
Regulatory Proteins ◽  
Thyroid Cells ◽  
Cycle Progression ◽  
Mapk Activity ◽  
Mitogen Activated Protein ◽  
Cell Cycle Regulatory Proteins ◽  
P38 Mapks

Objective: Thyrotropin activates the cAMP pathway in thyroid cells, and stimulates cell cycle progression in cooperation with insulin or insulin-like growth factor-I. Because p38 mitogen-activated protein kinases (p38 MAPKs) were stimulated by cAMP in the FRTL-5 rat thyroid cell line, we investigated (i) the effect of the specific inhibition of p38 MAPKs on FRTL-5 cell proliferation and (ii) the mechanism of action of p38 MAPKs on cell cycle control, by studying the expression and/or the activity of several cell cycle regulatory proteins in FRTL-5 cells. Methods: DNA synthesis was monitored by incorporation of [3H]thymidine into DNA and the cell cycle distribution was assessed by fluorescence-activated cell sorter analysis. Expression of cell cycle regulatory proteins was determined by Western blot analysis. Cyclin-dependent kinase 2 (Cdk2) activity associated to cyclin E was immunoprecipitated and was measured by an in vitro kinase assay. Results: SB203580, an inhibitor of α and β isoforms of p38 MAPKs, but not its inactive analog SB202474, inhibited DNA synthesis and the G1-S transition induced by forskolin plus insulin. SB203580 inhibited specifically p38 MAPK activity but not other kinase activities such as Akt and p70-S6 kinase. Treatment of FRTL-5 cells with SB203580 decreased total and cyclin E-associated Cdk2 kinase activity stimulated with forskolin and insulin. However, inhibition of p38 MAPKs by SB203580 was without effect on total cyclin E and Cdk2 levels. The decrease in Cdk2 kinase activity caused by SB203580 treatment was not due to an increased expression of p21Cip1 or p27Kip1 inhibitory proteins. In addition, SB203580 affected neither Cdc25A phosphatase expression nor Cdk2 Tyr-15 phosphorylation. Inhibition of p38 MAPKs decreased Cdk2-cyclin E activation by regulating the subcellular localization of Cdk2 and its phosphorylation on Thr-160. Conclusions: These results indicate that p38 MAPK activity is involved in the regulation of cell cycle progression in FRTL-5 thyroid cells, at least in part by increasing nuclear Cdk2 activity.

scholarly journals Transgene Expression of bcl-xL Permits Anti-immunoglobulin (Ig)–induced Proliferation in xid B Cells

1998 ◽  
Vol 187 (7) ◽  
pp. 1081-1091 ◽  
Author(s):  
Nanette Solvason ◽  
Wei Wei Wu ◽  
Nisha Kabra ◽  
Fridjtof Lund-Johansen ◽  
Maria Grazia Roncarolo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
B Cells ◽  
Transgene Expression ◽  
Cell Cycle Progression ◽  
Regulatory Protein ◽  
Ectopic Expression ◽  
Regulatory Proteins ◽  
High Rate ◽  
Cycle Progression ◽  
Cell Cycle Regulatory Proteins

Mutations in the tyrosine kinase, Btk, result in a mild immunodeficiency in mice (xid). While B lymphocytes from xid mice do not proliferate to anti-immunoglobulin (Ig), we show here induction of the complete complement of cell cycle regulatory molecules, though the level of induction is about half that detected in normal B cells. Cell cycle analysis reveals that anti-Ig stimulated xid B cells enter S phase, but fail to complete the cell cycle, exhibiting a high rate of apoptosis. This correlated with a decreased ability to induce the anti-apoptosis regulatory protein, Bcl-xL. Ectopic expression of Bcl-xL in xid B cells permitted anti-Ig induced cell cycle progression demonstrating dual requirements for induction of anti-apoptotic proteins plus cell cycle regulatory proteins during antigen receptor mediated proliferation. Furthermore, our results link one of the immunodeficient traits caused by mutant Btk with the failure to properly regulate Bcl-xL.

Rapamycin-induced G1 arrest in cycling B-CLL cells is associated with reduced expression of cyclin D3, cyclin E, cyclin A, and survivin

Blood ◽  
2003 ◽  
Vol 101 (1) ◽  
pp. 278-285 ◽  
Author(s):  
Thomas Decker ◽  
Susanne Hipp ◽  
Ingo Ringshausen ◽  
Christian Bogner ◽  
Madlene Oelsner ◽  
...  
Keyword(s):  
Cell Cycle ◽  
B Cells ◽  
Cell Cycle Regulation ◽  
Cell Cycle Progression ◽  
Cyclin E ◽  
Cyclin A ◽  
Cyclin D3 ◽  
G1 Arrest ◽  
Cycle Progression ◽  
Cycle Regulation

Abstract In B-cell chronic lymphocytic leukemia (B-CLL), malignant cells seem to be arrested in the G0/early G1phase of the cell cycle, and defective apoptosis might be involved in disease progression. However, increasing evidence exists that B-CLL is more than a disease consisting of slowly accumulating resting B cells: a proliferating pool of cells has been described in lymph nodes and bone marrow and might feed the accumulating pool in the blood. Rapamycin has been reported to inhibit cell cycle progression in a variety of cell types, including human B cells, and has shown activity against a broad range of human tumor cell lines. Therefore, we investigated the ability of rapamycin to block cell cycle progression in proliferating B-CLL cells. We have recently demonstrated that stimulation with CpG-oligonucleotides and interleukin-2 provides a valuable model for studying cell cycle regulation in malignant B cells. In our present study, we demonstrated that rapamycin induced cell cycle arrest in proliferating B-CLL cells and inhibited phosphorylation of p70s6 kinase (p70s6k). In contrast to previous reports on nonmalignant B cells, the expression of the cell cycle inhibitor p27 was not changed in rapamycin-treated leukemic cells. Treatment with rapamycin prevented retinoblastoma protein (RB) phosphorylation in B-CLL cells without affecting the expression of cyclin D2, but cyclin D3 was no longer detectable in rapamycin-treated B-CLL cells. In addition, rapamycin treatment inhibited cyclin-dependent kinase 2 activity by preventing up-regulation of cyclin E and cyclin A. Interestingly, survivin, which is expressed in the proliferation centers of B-CLL patients in vivo, is not up-regulated in rapamycin-treated cells. Therefore, rapamycin interferes with the expression of many critical molecules for cell cycle regulation in cycling B-CLL cells. We conclude from our study that rapamycin might be an attractive substance for therapy for B-CLL patients by inducing a G1 arrest in proliferating tumor cells.

scholarly journals Involvement of the STAT5-cyclin D/CDK4-pRb pathway in β-cell proliferation stimulated by prolactin during pregnancy

2019 ◽  
Vol 316 (1) ◽  
pp. E135-E144 ◽  
Author(s):  
Xin Zhao ◽  
Yili Xu ◽  
Ya Wu ◽  
Hui Zhang ◽  
Houxia Shi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Progression ◽  
Cell Mass ◽  
Cyclin D ◽  
Β Cell ◽  
Cycle Progression ◽  
Rb Phosphorylation ◽  
Insulinoma Cells

During pregnancy, maternal pancreatic β-cells undergo a compensatory expansion in response to the state of insulin resistance, where prolactin (PRL) plays a major role. Retinoblastoma protein (Rb) has been shown to critically regulate islet proliferation and function. The aim of the study was to explore the role of Rb in β-cell mass expansion during pregnancy. Expression of pocket protein family and E2Fs were examined in mouse islets during pregnancy and in insulinoma cells (INS-1) stimulated by PRL. PRL-stimulated INS-1 cells were used to explore the signaling pathway that regulates Rb downstream of the PRL receptor. Pancreas-specific Rb-knockout (Rb-KO) mice were assessed to evaluate the in vivo function of Rb in β-cell proliferation during pregnancy. During pregnancy, expression of Rb, phospho-Rb (p-Rb), p107, and E2F1 increased, while p130 decreased in maternal islets. With PRL stimulation, induction of Rb expression occurred mainly in the nucleus, while p-Rb was predominantly in the cytoplasm. Inhibition of STAT5 significantly restrained the expression of CDK4, Rb, p-Rb, and E2F1 in PRL-stimulated INS-1 cells with attenuation in cell cycle progression. Reduction of Rb phosphorylation by CDK4 inhibition blocked PRL-mediated proliferation of INS-1 cells. On the other hand, knockdown of Rb using siRNA led to an induction in E2F1 leading to cell cycle progression from G1 to S and G2/M phase, similar to the effects of PRL-mediated induction of p-Rb that led to cell proliferation. With Rb knockdown, PRL did not lead to further increase in cell cycle progression. Similarly, while Rb-KO pregnant mice displayed better glucose tolerance and higher insulin secretion, they had similar β-cell mass and proliferation to wild-type pregnant controls, supporting the essential role of Rb suppression in augmenting β-cell proliferation during pregnancy. Rb-E2F1 regulation plays a pivotal role in PRL-stimulated β-cell proliferation. PRL promotes Rb phosphorylation and E2F1 upregulation via STAT5-cyclin D/CDK4 pathway during pregnancy.

scholarly journals Tissue Inhibitor of Matrix Metalloproteinases-1 Knockdown Suppresses the Proliferation of Human Adipose-Derived Stem Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Peihua Zhang ◽  
Jin Li ◽  
Yawei Qi ◽  
Xudong Tang ◽  
Jianfeng Duan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Cell Proliferation ◽  
Western Blotting ◽  
Cell Cycle Progression ◽  
Cyclin E ◽  
Adipose Derived Stem Cells ◽  
Tissue Inhibitor ◽  
Cycle Progression ◽  
Protein Levels

Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a multifunctional matrix metalloproteinase, and it is involved in the regulation of cell proliferation and apoptosis in various cell types. However, little is known about the effect of TIMP-1 expression on the proliferation of adipose-derived stem cells (ADSCs). Therefore, TIMP-1 expression in the ADSCs was firstly detected by western blotting, and TIMP-1 gene was knocked down by lentivirus-mediated shRNA. Cell proliferation was then evaluated by MTT assay and Ki67 staining, respectively. Cell cycle progression was determined by flow cytometry. The changes of p51, p21, cyclin E, cyclin-dependent kinase 2 (CDK2), and P-CDK2 caused by TIMP-1 knockdown were detected by western blotting. The results indicated that ADSCs highly expressed TIMP-1 protein, and the knockdown of TIMP-1 inhibited cell proliferation and arrested cell cycle progression at G1phase in the ADSCs possibly through the upregulation of p53, p21, and P-CDK2 protein levels and concurrent downregulation of cyclin E and CDK2 protein levels. These findings suggest that TIMP-1 works as a positive regulator of cell proliferation in ADSCs.

scholarly journals Nuclear envelope influences on cell-cycle progression

2011 ◽  
Vol 39 (6) ◽  
pp. 1742-1746 ◽  
Author(s):  
Vlastimil Srsen ◽  
Nadia Korfali ◽  
Eric C. Schirmer
Keyword(s):  
Cell Cycle ◽  
Nuclear Envelope ◽  
Cell Cycle Progression ◽  
Membrane System ◽  
Regulatory Proteins ◽  
Cycle Progression ◽  
Cytoplasmic Surface ◽  
Dynamic Interface ◽  
Gene Regulatory ◽  
Cycle Regulation

The nuclear envelope is a complex double membrane system that serves as a dynamic interface between the nuclear and cytoplasmic compartments. Among its many roles is to provide an anchor for gene regulatory proteins on its nucleoplasmic surface and for the cytoskeleton on its cytoplasmic surface. Both sets of anchors are proteins called NETs (nuclear envelope transmembrane proteins), embedded respectively in the inner or outer nuclear membranes. Several lines of evidence indicate that the nuclear envelope contributes to cell-cycle regulation. These contributions come from both inner and outer nuclear membrane NETs and appear to operate through several distinct mechanisms ranging from sequestration of gene-regulatory proteins to activating kinase cascades.

scholarly journals Naringin as a natural bitter tastant promotes proliferation of cultured human bronchial epithelial cells via activation of TAS2R signaling

2020 ◽  
Author(s):  
Kai Ni ◽  
Mingzhi Luo ◽  
Bing Bu ◽  
Jia Guo ◽  
Yan Pan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Epithelial Cells ◽  
Calcium Signaling ◽  
Cell Cycle Progression ◽  
Cyclin E ◽  
Asthma Therapy ◽  
Cycle Progression ◽  
Bronchial Epithelial

Abstract Bitter tastants can activate bitter taste receptors (TAS2Rs) and thus initiate the relaxation of airway smooth muscle cells, which have great potential in the development of novel asthma therapy. However, recent study shows that canonical bitter substance denatonium induces apoptosis of bronchial epithelial cells (BECs), indicating the toxic effect of bitter tastants on airways. Considering the diversity of bitter tastants in nature and TAS2Rs expressed in airway cells, it is thus necessary to carefully evaluate the bitter tastant for its effect on the proliferation of BECs, if aimed to treat airway disease. Here we first screened a group of bitter flavonoids, including apignenin, hespretin, kaempferol, naringenin, naringin and quercetin which are commonly used in food and traditional medicine, and then quantitatively evaluated the effects of this group of bitter flavonoids on the proliferation of BECs (i.e. 16HBE14o- cells) cultured in vitro. The results show that five of the six tested bitter tastants inhibited, but only naringin promoted the proliferation of 16HBE14o- BECs in vitro at the dose of a few hundred micromoles. Furthermore, the naringin-promoted cell proliferation was associated with enhanced cell cycle progression, mRNA expression of cyclin E, and evoked calcium signaling/ERK signaling. Inhibition of the TAS2R signaling pathways with specific blockers attenuated the naringin-enhanced cell proliferation, cyclin E expression and calcium signaling/ERK activation. Taken together, these findings indicate that although many bitter flavonoids may inhibit the proliferation of BECs, naringin emerges as one of the kind that promotes the proliferation of BECs via cell cycle progression and TAS2R-activated intracellular signaling. Only such bitter tastant proven to be unharmful to the epithelial structure and function could be further developed as safe and effective TAS2Rs-based bronchodilator in asthma therapy.

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