scholarly journals Tetramethylpyrazine Inhibits Activation of Hepatic Stellate Cells through Hedgehog Signaling Pathways In Vitro

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Jue Hu ◽  
Gang Cao ◽  
Xin Wu ◽  
Hao Cai ◽  
Baochang Cai
Keyword(s):  
Cyclin D1 ◽  
Hepatic Fibrosis ◽  
Hedgehog Signaling ◽  
Stellate Cell ◽  
Inhibitory Effect ◽  
Tissue Growth ◽  
Cyclin Dependent Kinase ◽  
Western Blot Assay ◽  
Cyclin E1

Background and Aim. Tetramethylpyrazine (TMP), a major alkaloid isolated fromLigusticum chuanxiong, has been reported in hepatic fibrosis models. However, the action mechanism remains unclear. In the present study, effects of tetramethylpyrazine (TMP) against hepatic stellate cell (HSC) activation as well as the possible mechanisms were evaluated.Methods. Western blot assay was used to detect TMP effects on protein expression of Smo, Patched, Hhip, and Gli and to investigate the effects of TMP on Cyclin D1, Cyclin E1, CDK2, Bcl-2, Bax, and caspase expression with cyclopamine supplementation.Results. Our results showed that TMP significantly inhibits the expression of Cyclin D1, Cyclin E1, and Cyclin-dependent kinase CDK2 and changes the HSC cycle by inhibiting the proliferation of HSC. Moreover, TMP has also been shown to decrease the expression of Bcl-2 and increase the expression of Bax in HSC-T6 cells. Furthermore, TMP can inhibit the expression of connective tissue growth factor (CTGF), and the inhibitory effect was intensified after the application of joint treatment with TMP and cyclopamine.Conclusion. TMP may be an effective Hh signaling pathway inhibitor for hepatic fibrosis treatment.

Beauvericin Inhibits the Growth of U251 Glioma Cells and Promotes Apoptosis In Vitro

2020 ◽  
Vol 14 (5) ◽  
pp. 639-644
Author(s):  
Liming Hu ◽  
Tianyi Zhao ◽  
Jia Wang ◽  
Renguang Wang ◽  
Hongshi Bu ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Glioma Cells ◽  
Inhibitory Effect ◽  
U251 Cell ◽  
Western Blot Assay ◽  
Expression Levels ◽  
Signal Transduction Proteins

To elucidated the inhibitory effect of beauvericin (BEA) on glioma cells and its possible molecular mechanism, in this study, the MTT assay was performed to observed the effect of BEA on cell proliferation, the flow cytometry was used to measure its protective effect on cell apoptosis, and the Western Blot assay was performed to test the expression levels of signal transduction proteins. In the results, the concentration of BEA was 0.5 μmoL/L in the drug group, indicating that it has obvious protect effect to the U251 cells. The apoptosis rates of BEA, Cis and BEA+Cis groups, compared with the U251 group, were 2.93, 3.71 and 5.0 times higher respectively. In addition, the expression levels of Cyclin D1, E, B and Bcl-2 in BEA group were 75, 69, 78 and 67% of that in the U251 group, while Bax and cleaved caspase-3 were twice as much as that in the U251 group. In conclusion, beauvericin can inhibit U251 cell apoptosis and the possible mechanism is to reduce the expression of Cyclin D1, B, E and Bcl-2, while the levels of Bax and cleaved Caspase-3 increased. Thus, BEA has a broad application prospect in the treatment of glioma.

scholarly journals Inhibitory effect of oestradiol on activation of rat hepatic stellate cells in vivo and in vitro

Gut ◽  
1999 ◽  
Vol 44 (1) ◽  
pp. 127-136 ◽  
Author(s):  
I Shimizu ◽  
Y Mizobuchi ◽  
M Yasuda ◽  
M Shiba ◽  
Y-R Ma ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Inhibitory Effect ◽  
Type I ◽  
Mrna Levels ◽  
Pig Serum

BackgroundHepatic stellate cells play a key role in the pathogenesis of hepatic fibrosis.AimsTo examine the inhibitory effect of oestradiol on stellate cell activation.MethodsIn vivo, hepatic fibrosis was induced in rats by dimethylnitrosamine or pig serum. In vitro, rat stellate cells were activated by contact with plastic dishes resulting in their transformation into myofibroblast-like cells.ResultsIn the dimethylnitrosamine and pig serum models, treatment with oestradiol at gestation related doses resulted in a dose dependent suppression of hepatic fibrosis with restored content of hepatic retinyl palmitate, reduced collagen content, lower areas of stellate cells which express α smooth muscle actin (α-SMA) and desmin, and lower procollagen type I and III mRNA levels in the liver. In cultured stellate cells, oestradiol inhibited type I collagen production, α-SMA expression, and cell proliferation. These findings suggest that oestradiol is a potent inhibitor of stellate cell transformation.ConclusionThe antifibrogenic role of oestradiol in the liver may contribute to the sex associated differences in the progression from hepatic fibrosis to cirrhosis.

scholarly journals Combined Luteolin and Indole-3-Carbinol Synergistically Constrains ERα-Positive Breast Cancer by Dual Inhibiting Estrogen Receptor Alpha and Cyclin-Dependent Kinase 4/6 Pathway in Cultured Cells and Xenograft Mice

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2116
Author(s):  
Xiaoyong Wang ◽  
Lijuan Zhang ◽  
Qi Dai ◽  
Hongzong Si ◽  
Longyun Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cell ◽  
Breast Cancer Cells ◽  
Cultured Cells ◽  
Inhibitory Effect ◽  
Cyclin Dependent Kinase ◽  
Xenograft Mice ◽  
The Individual

The high concentrations of individual phytochemicals in vitro studies cannot be physiologically achieved in humans. Our solution for this concentration gap between in vitro and human studies is to combine two or more phytochemicals. We screened 12 phytochemicals by pairwise combining two compounds at a low level to select combinations exerting the synergistic inhibitory effect of breast cancer cell proliferation. A novel combination of luteolin at 30 μM (LUT30) and indole-3-carbinol 40 μM (I3C40) identified that this combination (L30I40) synergistically constrains ERα+ breast cancer cell (MCF7 and T47D) proliferation only, but not triple-negative breast cancer cells. At the same time, the individual LUT30 and I3C40 do not have this anti-proliferative effect in ERα+ breast cancer cells. Moreover, this combination L30I40 does not have toxicity on endothelial cells compared to the current commercial drugs. Similarly, the combination of LUT and I3C (LUT10 mg + I3C10 mg/kg/day) (IP injection) synergistically suppresses tumor growth in MCF7 cells-derived xenograft mice, but the individual LUT (10 mg/kg/day) and I3C (20 mg/kg/day) do not show an inhibitory effect. This combination synergistically downregulates two major therapeutic targets ERα and cyclin dependent kinase (CDK) 4/6/retinoblastoma (Rb) pathway, both in cultured cells and xenograft tumors. These results provide a solid foundation that a combination of LUT and I3C may be a practical approach to treat ERα+ breast cancer cells after clinical trials.

scholarly journals Sestrin 2 Attenuates Rat Hepatic Stellate Cell (HSC) Activation and Liver Fibrosis via an mTOR/AMPK-Dependent Mechanism

2018 ◽  
Vol 51 (5) ◽  
pp. 2111-2122 ◽  
Author(s):  
Yi-Bing Hu ◽  
Xiao-Ting Ye ◽  
Qing-Qing Zhou ◽  
Rong-Quan Fu
Keyword(s):  
Liver Fibrosis ◽  
Protein Expression ◽  
Hepatic Fibrosis ◽  
Transforming Growth Factor ◽  
Histopathological Examination ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
Mrna Levels ◽  
Alpha Smooth Muscle Actin

Background/Aims: Sestrin 2 is associated with the pathophysiology of several diseases. The aim of this study was to investigate the effects and potential mechanisms of Sestrin 2 in rat hepatic stellate cells (HSCs) during liver fibrogenesis. Methods: In this study, Sestrin 2 protein expression was detected in rat HSC-T6 cells challenged with transforming growth factor-β (TGF-β) and in mice treated with carbon tetrachloride (CCl4), a well-known model of hepatic fibrosis. Next, HSC-T6 cells and fibrotic mice were transfected with lentivirus. The mRNA expression levels of markers of liver fibrosis [alpha-smooth muscle actin (α-SMA) and collagen 1A1 (Col1A1)] were analyzed by quantitative reverse transcription–polymerase chain reaction (RT-PCR). Cell death and proliferation were evaluated by the MTT assay, and biochemical markers of liver damage in serum [alanine transaminase (ALT) and aspartate transaminase (AST)] were also measured using a biochemical analyzer. Histopathological examination was used to evaluate the degree of liver fibrosis, and protein expression [phospho-adenosine monophosphate-activated protein kinase (p-AMPK), AMPK, phospho-mammalian target of rapamycin (p-mTOR), and mTOR] was determined by western blotting. Results: We found that Sestrin 2 was elevated in both the HSC-T6 cell and hepatic fibrosis models. In vitro, overexpression of Sestrin 2 attenuated the mRNA levels of α-SMA and Col1A1, suppressed α-SMA protein expression, and modulated HSC-T6 cell proliferation. In vivo, overexpression of Sestrin 2 reduced the ALT and AST levels as well as the α-SMA and Col1A1 protein expression in the CCl4 model of liver fibrosis. Moreover, the degree of liver fibrosis was ameliorated. Interestingly, overexpression of Sestrin 2 increased p-AMPK but decreased p-mTOR protein expression. Conclusion: Our findings indicate that Sestrin 2 may attenuate the activation of HSCs and ameliorate liver fibrosis, most likely via upregulation of AMPK phosphorylation and suppression of the mTOR signaling pathway.

scholarly journals Cyclin E1 and cyclin-dependent kinase 2 are critical for initiation, but not for progression of hepatocellular carcinoma

2018 ◽  
Vol 115 (37) ◽  
pp. 9282-9287 ◽  
Author(s):  
Roland Sonntag ◽  
Nives Giebeler ◽  
Yulia A. Nevzorova ◽  
Jörg-Martin Bangen ◽  
Dirk Fahrenkamp ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Gene Signature ◽  
Cyclin Dependent Kinase ◽  
Regulatory Subunits ◽  
Cyclin E1 ◽  
Quiescent Cells ◽  
Similar Expression Profile ◽  
Regulation Of Cell Cycle

E-type cyclins E1 (CcnE1) and E2 (CcnE2) are regulatory subunits of cyclin-dependent kinase 2 (Cdk2) and thought to control the transition of quiescent cells into the cell cycle. Initial findings indicated that CcnE1 and CcnE2 have largely overlapping functions for cancer development in several tumor entities including hepatocellular carcinoma (HCC). In the present study, we dissected the differential contributions of CcnE1, CcnE2, and Cdk2 for initiation and progression of HCC in mice and patients. To this end, we tested the HCC susceptibility in mice with constitutive deficiency for CcnE1 or CcnE2 as well as in mice lacking Cdk2 in hepatocytes. Genetic inactivation of CcnE1 largely prevented development of liver cancer in mice in two established HCC models, while ablation of CcnE2 had no effect on hepatocarcinogenesis. Importantly, CcnE1-driven HCC initiation was dependent on Cdk2. However, isolated primary hepatoma cells typically acquired independence on CcnE1 and Cdk2 with increasing progression in vitro, which was associated with a gene signature involving secondary induction of CcnE2 and up-regulation of cell cycle and DNA repair pathways. Importantly, a similar expression profile was also found in HCC patients with elevated CcnE2 expression and poor survival. In general, overall survival in HCC patients was synergistically affected by expression of CcnE1 and CcnE2, but not through Cdk2. Our study suggests that HCC initiation specifically depends on CcnE1 and Cdk2, while HCC progression requires expression of any E-cyclin, but no Cdk2.

scholarly journals A dominant-negative cyclin D1 mutant prevents nuclear import of cyclin-dependent kinase 4 (CDK4) and its phosphorylation by CDK-activating kinase.

1997 ◽  
Vol 17 (12) ◽  
pp. 7362-7374 ◽  
Author(s):  
J A Diehl ◽  
C J Sherr
Keyword(s):  
Cyclin D1 ◽  
Nuclear Localization ◽  
Mammalian Cells ◽  
Phosphorylation Site ◽  
Dominant Negative ◽  
Cyclin Dependent Kinase ◽  
Linker Peptide ◽  
Cdk Activating Kinase

Cyclins contain two characteristic cyclin folds, each consisting of five alpha-helical bundles, which are connected to one another by a short linker peptide. The first repeat makes direct contact with cyclin-dependent kinase (CDK) subunits in assembled holoenzyme complexes, whereas the second does not contribute directly to the CDK interface. Although threonine 156 in mouse cyclin D1 is predicted to lie at the carboxyl terminus of the linker peptide that separates the two cyclin folds and is buried within the cyclin subunit, mutation of this residue to alanine has profound effects on the behavior of the derived cyclin D1-CDK4 complexes. CDK4 in complexes with mutant cyclin D1 (T156A or T156E but not T156S) is not phosphorylated by recombinant CDK-activating kinase (CAK) in vitro, fails to undergo activating T-loop phosphorylation in vivo, and remains catalytically inactive and unable to phosphorylate the retinoblastoma protein. Moreover, when it is ectopically overexpressed in mammalian cells, cyclin D1 (T156A) assembles with CDK4 in the cytoplasm but is not imported into the cell nucleus. CAK phosphorylation is not required for nuclear transport of cyclin D1-CDK4 complexes, because complexes containing wild-type cyclin D1 and a CDK4 (T172A) mutant lacking the CAK phosphorylation site are efficiently imported. In contrast, enforced overexpression of the CDK inhibitor p21Cip1 together with mutant cyclin D1 (T156A)-CDK4 complexes enhanced their nuclear localization. These results suggest that cyclin D1 (T156A or T156E) forms abortive complexes with CDK4 that prevent recognition by CAK and by other cellular factors that are required for their nuclear localization. These properties enable ectopically overexpressed cyclin D1 (T156A), or a more stable T156A/T286A double mutant that is resistant to ubiquitination, to compete with endogenous cyclin D1 in mammalian cells, thereby mobilizing CDK4 into cytoplasmic, catalytically inactive complexes and dominantly inhibiting the ability of transfected NIH 3T3 fibroblasts to enter S phase.

scholarly journals Reversal of Growth Suppression by p107 via Direct Phosphorylation by Cyclin D1/Cyclin-Dependent Kinase 4

2002 ◽  
Vol 22 (7) ◽  
pp. 2242-2254 ◽  
Author(s):  
Xiaohong Leng ◽  
Martin Noble ◽  
Peter D. Adams ◽  
Jun Qin ◽  
J. Wade Harper
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Control Cell ◽  
Growth Suppression ◽  
Cyclin Dependent Kinase ◽  
Culture Cells ◽  
Cycle Arrest ◽  
A Cell ◽  
Control Cell Division

ABSTRACT p107 functions to control cell division and development through interaction with members of the E2F family of transcription factors. p107 is phosphorylated in a cell cycle-regulated manner, and its phosphorylation leads to its release from E2F. Although it is known that p107 physically associates with E- and A-type cyclin/cyclin-dependent kinase 2 (Cdk2) complexes through a cyclin-binding RXL motif located in the spacer domain, the mechanisms underlying p107 inactivation via phosphorylation remain poorly defined. Recent genetic evidence indicates a requirement for cyclin D1/Cdk4 complexes in p107 inactivation. In this work, we provide direct biochemical evidence for the involvement of cyclin D1/Cdk4 in the inactivation of p107's growth-suppressive function. While coexpression of cyclin D1/Cdk4 can reverse the cell cycle arrest properties of p107 in Saos-2 cells, we find that p107 in which the Lys-Arg-Arg-Leu sequence of the RXL motif is replaced by four alanine residues is largely refractory to inactivation by cyclin D/Cdk4, indicating a role for this motif in p107 inactivation without a requirement for its tight interaction with cyclin D1/Cdk4. We identified four phosphorylation sites in p107 (Thr-369, Ser-640, Ser-964, and Ser-975) that are efficiently phosphorylated by Cdk4 but not by Cdk2 in vitro and are also phosphorylated in tissue culture cells. Growth suppression by p107 containing nonphosphorylatable residues in these four sites is not reversed by coexpression of cyclin D1/Cdk4. In model p107 spacer region peptides, phosphorylation of S640 by cyclin D1/Cdk4 is strictly dependent upon an intact RXL motif, but phosphorylation of this site in the absence of an RXL motif can be partially restored by replacement of S643 by arginine. This suggests that one role for the RXL motif is to facilitate phosphorylation of nonconsensus Cdk substrates. Taken together, these data indicate that p107 is inactivated by cyclin D1/Cdk4 via direct phosphorylation and that the RXL motif of p107 plays a role in its inactivation by Cdk4 in the absence of stable binding.

scholarly journals Isoliquiritigenin inhibits the proliferation, migration and metastasis of Hep3B cells via suppressing cyclin D1 and PI3K/AKT pathway

2020 ◽  
Vol 40 (1) ◽  
Author(s):  
Yun Huang ◽  
Chen Liu ◽  
Wu-Cha Zeng ◽  
Guo-Yan Xu ◽  
Jian-Min Wu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Inhibitory Effect ◽  
Cycle Arrest ◽  
Novel Drugs ◽  
Epithelial Marker ◽  
Hep3b Cells ◽  
Induced Apoptosis

Abstract The overall survival rate of patients with hepatocellular carcinoma (HCC) has remained unchanged over the last several decades. Therefore, novel drugs and therapies are required for HCC treatment. Isoliquiritigenin (ISL), a natural flavonoid predominantly isolated from the traditional Chinese medicine Glycyrrhizae Radix (Licorice), has a high anticancer potential and broad application value in various cancers. Here, we aimed to investigate the anticancer role of ISL in the HCC cell line Hep3B. Functional analysis revealed that ISL inhibited the proliferation of Hep3B cells by causing G1/S cell cycle arrest in vitro. Meanwhile, the inhibitory effect of ISL on proliferation was also observed in vivo. Further analysis revealed that ISL could suppress the migration and metastasis of Hep3B cells in vitro and in vivo. Mechanistic analysis revealed that ISL inhibited cyclin D1 and up-regulated the proteins P21, P27 that negatively regulate the cell cycle. Furthermore, ISL induced apoptosis while inhibiting cell cycle transition. In addition, phosphatidylinositol 3′-kinase/protein kinase B (PI3K/AKT) signal pathway was suppressed by ISL treatment, and the epithelial marker E-cadherin was up-regulated when the mesenchymal markers Vimentin and N-cadherin were down-regulated. In brief, our findings suggest that ISL could be a promising agent for preventing HCC tumorigenesis and metastasis.

Progesterone Antagonizes Dexamethasone-Regulated Surfactant Proteins In Vitro

2018 ◽  
Vol 26 (8) ◽  
pp. 1062-1070 ◽  
Author(s):  
Steffen Kunzmann ◽  
Barbara Ottensmeier ◽  
Christian P. Speer ◽  
Markus Fehrholz
Keyword(s):  
Epithelial Cells ◽  
Messenger Rna ◽  
Protein A ◽  
Inhibitory Effect ◽  
Tissue Growth ◽  
Lung Epithelial Cells ◽  
Lung Maturation ◽  
Lung Epithelial ◽  
Tgf Β1

Pregnant women at risk of preterm labor routinely receive glucocorticoids (GCs) and frequently also progesterone. Administration of GCs accelerates intrauterine surfactant synthesis and lung maturation, thereby reducing the incidence of neonatal respiratory distress syndrome; progesterone has the potential to prevent preterm birth. Little is known about possible interactions of GCs and progesterone. Our aim was to clarify whether progesterone can affect dexamethasone (DXM)-regulated expression of surfactant protein A (SP-A), SP-B, and SP-D in lung epithelial cells. H441 cells were exposed to DXM and progesterone and expression of SPs was analyzed by quantitative real-time polymerase chain reaction and immunoblotting. Although progesterone had no direct effect on the expression of SP-B, DXM-mediated induction was inhibited dose dependently on the transcriptional (64 µM [ P < .0001], 32 µM [ P = .0005], 16 µM [ P = .0019]) and the translational level. Furthermore, progesterone inhibited stimulatory effects of other GCs as well. While exogenous tissue growth factor β1 (TGF-β1) inhibited DXM-induced SP-B expression (messenger RNA [mRNA]: P = .0014), progesterone itself did not influence TGF-β1 mRNA expression and/or TGF-β1/Smad signaling, demonstrating that TGF-β1 and/or Smad activation is not involved. The inhibitory effect of progesterone could be imitated by the GC and progesterone receptor (PR) antagonist RU-486, but not by the specific PR antagonist PF-02413873, indicating that progesterone acts as a competitive antagonist of DXM. The effect of progesterone on DXM-regulated genes was not specific for SP-B, as expression of SP-A and SP-D mRNAs was also antagonized. The present study highlights a new action of progesterone as a potential physiological inhibitor of GC-dependent SP expression in lung epithelial cells. The clinical relevance of this in vitro finding is currently unknown.

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