Distinct and sequential upregulation of genes regulating cell growth and cell cycle progression during hepatic ischemia-reperfusion injury

2005 ◽  
Vol 289 (4) ◽  
pp. C826-C835 ◽  
Author(s):  
Sharon Barone ◽  
Tomohisa Okaya ◽  
Steve Rudich ◽  
Snezana Petrovic ◽  
Kathy Tenrani ◽  
...  

Ischemia-reperfusion injury (IRI) in liver and other organs is manifested as an injury phase followed by recovery and resolution. Control of cell growth and proliferation is essential for recovery from the injury. We examined the expression of three related regulators of cell cycle progression in liver IRI: spermidine/spermine N-acetyltransferase (SSAT), p21 (a cyclin-dependent kinase inhibitor), and stathmin. Mice were subjected to hepatic IRI, and liver tissues were harvested at timed intervals. The expression of SSAT, the rate-limiting enzyme in the polyamine catabolic pathway, had increased fivefold 6 h after IRI and correlated with increased putrescine levels in the liver, consistent with increased SSAT enzymatic activity in IRI. The expression of p21, which is transactivated by p53, was undetectable in sham-operated animals but was heavily induced at 12 and 24 h of reperfusion and declined to undetectable baseline levels at 72 h of reperfusion. The interaction of the polyamine pathway with the p53-p21 pathway was shown in vitro, where activation of SSAT with polyamine analog or the addition of putrescine to cultured hepatocytes induced the expression of p53 and p21 and decreased cell viability. The expression of stathmin, which is under negative transcriptional regulation by p21 and controls cell proliferation and progression through mitosis, remained undetectable at 6, 12, and 24 h of reperfusion and was progressively and heavily induced at 48 and 72 h of reperfusion. Double-immunofluorescence labeling with antibodies against stathmin and PCNA, a marker of cell proliferation, demonstrated colocalization of stathmin and PCNA at 48 and 72 h of reperfusion in hepatocytes, indicating the initiation of cell proliferation. The distinct and sequential upregulation of SSAT, p21, and stathmin, along with biochemical activation of the polyamine catabolic pathway in IRI in vivo and the demonstration of p53-p21 upregulation by SSAT and putrescine in vitro, points to the important role of regulators of cell growth and cell cycle progression in the pathophysiology and/or recovery in liver IRI. The data further suggest that SSAT may play a role in the initiation of injury, whereas p21 and stathmin may be involved in the resolution and recovery after liver IRI.

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Chen-Hua Dong ◽  
Tao Jiang ◽  
Hang Yin ◽  
Hu Song ◽  
Yi Zhang ◽  
...  

AbstractColorectal cancer is the second common cause of death worldwide. Lamin B2 (LMNB2) is involved in chromatin remodeling and the rupture and reorganization of nuclear membrane during mitosis, which is necessary for eukaryotic cell proliferation. However, the role of LMNB2 in colorectal cancer (CRC) is poorly understood. This study explored the biological functions of LMNB2 in the progression of colorectal cancer and explored the possible molecular mechanisms. We found that LMNB2 was significantly upregulated in primary colorectal cancer tissues and cell lines, compared with paired non-cancerous tissues and normal colorectal epithelium. The high expression of LMNB2 in colorectal cancer tissues is significantly related to the clinicopathological characteristics of the patients and the shorter overall and disease-free cumulative survival. Functional analysis, including CCK8 cell proliferation test, EdU proliferation test, colony formation analysis, nude mouse xenograft, cell cycle, and apoptosis analysis showed that LMNB2 significantly promotes cell proliferation by promoting cell cycle progression in vivo and in vitro. In addition, gene set enrichment analysis, luciferase report analysis, and CHIP analysis showed that LMNB2 promotes cell proliferation by regulating the p21 promoter, whereas LMNB2 has no effect on cell apoptosis. In summary, these findings not only indicate that LMNB2 promotes the proliferation of colorectal cancer by regulating p21-mediated cell cycle progression, but also suggest the potential value of LMNB2 as a clinical prognostic marker and molecular therapy target.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2571-2571
Author(s):  
Zhi Hong Lu ◽  
Jason T. Books ◽  
Timothy James Ley

Abstract Mammalian proteins containing “cold-shock” domains belong to the most evolutionarily conserved family of nucleic acid-binding proteins known in bacteria, plants, and animals. One of these proteins, YB-1, has been implicated in basic cellular functions such as cell proliferation and responses to environmental stresses. In mammalian cells, YB-1 has been shown to shuttle between the nuclear and cytoplasmic compartments. Within the nucleus, YB-1 interacts with several DNA-and pre-mRNA-binding proteins, and has been implicated in nuclear activities, including transcriptional regulation, chromatin remodeling, and pre-mRNA splicing. YB-1 is also abundant in the cytoplasm, where it binds nonspecifically to mRNA, and may act as a general regulator of mRNA stability, cytoplasmic localization, and translation. Thus, YB-1 has been proposed to function as a multifunctional regulator for the control of gene expression in both the nucleus and cytoplasm. YB-1 overexpression has been frequently detected in a variety of human cancers, often associated with unfavorable clinical outcomes. However, it remains unclear whether YB-1 overexpression contributes directly to the malignant phenotype, or whether it is simply a non-causal “marker” associated with rapid cell growth (and poor prognostic outcomes). To further assess the role of this protein in health and disease, we created mice deficient for YB-1. Complete loss of function of this gene results in fully-penetrant late embryonic and perinatal lethality. Morphological and histological analyses revealed that YB-1−/− embryos displayed major developmental and functional defects, including neurological abnormalities, hemorrhage, and respiratory failure, which probably contributed to lethality. Growth retardation occurred in all late-stage embryos, and was the result of hypoplasia in multiple organ systems. Consistent with these in vivo results, fibroblasts isolated from YB-1−/− embryos (MEFs) grew slowly and entered senescence prematurely in vitro; these defects were rescued by ectopic expression of a GFP-tagged human YB-1 cDNA. This data suggests that YB-1 plays an important cell-autonomous role in cell proliferation and prevention of premature senescence. We further showed that loss of YB-1 in early passage MEFs resulted a delay in G0/G1 to S-phase progression, and a defect in a transcriptional mechanism that normally represses the expression of the G1-specific CDK inhibitor gene p16Ink4a, and the p53 target genes p21Cip1 and Mdm2. However, YB-1 does not cause “global” changes in the transcriptome, the proteome, or protein synthesis efficiency. As predicted, p16Ink4a and p21Cip1 double knockdown by siRNA treatment led to an increase in the rate of cell proliferation, and an extension of proliferative capacity during late passages in YB-1−/− cells. Furthermore, YB-1 deficiency reduced the ability of MEFs to proliferate normally in response to c-Myc overexpression. In conclusion, our data has revealed that YB-1 is required for normal mouse development and survival, and that it plays an important role in supporting rapid cellular proliferation both in vivo and in vitro. Our data further suggests that YB-1 is a cell cycle progression regulator that is important for preventing the early onset of senescence in cultured MEF cells. This data raises the possibility that disregulated expression of YB-1 may contribute to malignant phenotypes by supporting rapid cell cycle progression, and by protecting cells from cytotoxic stresses.


2002 ◽  
Vol 22 (18) ◽  
pp. 6509-6520 ◽  
Author(s):  
Tetsuo Maruyama ◽  
Andrea Farina ◽  
Anup Dey ◽  
JaeHun Cheong ◽  
Vladimir P. Bermudez ◽  
...  

ABSTRACT Brd4 belongs to the BET family of nuclear proteins that carry two bromodomains implicated in the interaction with chromatin. Expression of Brd4 correlates with cell growth and is induced during early G1 upon mitogenic stimuli. In the present study, we investigated the role of Brd4 in cell growth regulation. We found that ectopic expression of Brd4 in NIH 3T3 and HeLa cells inhibits cell cycle progression from G1 to S. Coimmunoprecipitation experiments showed that endogenous and transfected Brd4 interacts with replication factor C (RFC), the conserved five-subunit complex essential for DNA replication. In vitro analysis showed that Brd4 binds directly to the largest subunit, RFC-140, thereby interacting with the entire RFC. In line with the inhibitory activity seen in vivo, recombinant Brd4 inhibited RFC-dependent DNA elongation reactions in vitro. Analysis of Brd4 deletion mutants indicated that both the interaction with RFC-140 and the inhibition of entry into S phase are dependent on the second bromodomain of Brd4. Lastly, supporting the functional importance of this interaction, it was found that cotransfection with RFC-140 reduced the growth-inhibitory effect of Brd4. Taken as a whole, the present study suggests that Brd4 regulates cell cycle progression in part by interacting with RFC.


2020 ◽  
Author(s):  
Chen-Hua Dong ◽  
Tao Jiang ◽  
Hang Yin ◽  
Hu Song ◽  
Yi Zhang ◽  
...  

Abstract Background: Lamin B2 (LMNB2) is involved in chromatin remodelling and the rupture and reorganization of the nuclear membrane during mitosis, which is necessary for eukaryotic cell proliferation. However, there are few reports on the expression and function of LMNB2 in colorectal cancer.Methods: A tissue microarray (TAM) was used to detect the expression of LMNB2 in 226 colorectal cancer tissues and the corresponding adjacent tissues. The CCK-8 colorimetric assay, EdU incorporation analyses, colony formation assays and cell cycle experiments were used to evaluate the effect of LMNB2 on colorectal cancer cell proliferation in vitro, and a mouse tumorigenic model was used to study the effect of LMNB2 on colorectal cancer cells in vivo. The main pathways and genes regulated by LMNB2 were detected by RNA sequencing. Dual-luciferase reporter assays were conducted to test the direct binding between LMNB2 and p21, and ChIP analysis showed that LMNB2 promotes cell proliferation by regulating the p21 promoter.Results: The results showed that LMNB2 expression is increased in colorectal cancer tissues. Highly expressed LMNB2 is associated with tumour size and TNM stage. Multivariate Cox analysis showed that LMNB2 can be used as an independent prognostic factor in patients with colorectal cancer. Functional assays indicated that LMNB2 obviously enhanced cell proliferation by promoting cell cycle progression in vitro and in vivo. LMNB2 facilitates cell proliferation via regulating the p21 promoter, whereas LMNB2 had no effect on cell apoptosis in terms of mechanism.Conclusion: LMNB2 promotes the proliferation of colorectal cancer by regulating p21-mediated cell cycle progression, indicating the potential value of LMNB2 as a clinical prognostic marker and molecular therapeutic target.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Qiongyi Pang ◽  
Yun Zhao ◽  
Xiang Chen ◽  
Kaiyi Zhao ◽  
Qiongxiang Zhai ◽  
...  

Apigenin is a natural flavonoid found in several dietary plant foods as vegetables and fruits. To investigate potential anti-ischemia/reperfusion injury properties of apigenin in vitro, cell proliferation assay, tube formation, cell migration, apoptosis, and autophagy were performed in human brain microvascular endothelial cells (HBMVECs) after oxygen-glucose deprivation/reoxygenation (OGD/R). The effect of apigenin was also explored in rats after middle cerebral artery occlusion/reperfusion (MCAO/R) via neurobehavioral scores, pathological examination, and measurement of markers involved in ischemia/reperfusion injury. Data in vitro indicated that apigenin could prompt cell proliferation, tube formation, and cell migration while inhibiting apoptosis and autophagy by affecting Caveolin-1/VEGF, Bcl-2, Caspase-3, Beclin-1, and mTOR expression. Results in vivo showed that apigenin significantly reduced neurobehavioral scores and volume of cerebral infarction while prompting vascular endothelial cell proliferation by upregulating VEGFR2/CD34 double-labeling endothelial progenitor cell (EPC) number and affecting Caveolin-1, VEGF, and eNOS expression in brain tissue of MCAO/R rats. All the data suggested that apigenin may be protective for the brain against ischemia/reperfusion injury by alleviating apoptosis and autophagy, promoting cell proliferation in HBMVECs of OGD/R, and attenuating brain damage and improved neurological function in rats of MCAO/R through the Caveolin-1/VEGF pathway.


2001 ◽  
Vol 61 (5) ◽  
pp. 565-571 ◽  
Author(s):  
Yaniv Eli ◽  
Fiorenza Przedecki ◽  
Galit Levin ◽  
Na’am Kariv ◽  
Amiram Raz

2021 ◽  
Author(s):  
Yeqing Zhou ◽  
Hongmei Yong ◽  
Sufang Chu ◽  
Minle Li ◽  
Zhongwei Li ◽  
...  

Abstract Background As the most commonly diagnosed lung cancer, non–small cell lung carcinoma (NSCLC) is regulated by many long noncoding RNAs (lncRNAs). In the present study, we found that SH3PXD2A-AS1 expression in NSCLC tissues was upregulated compared with that in normal lung tissues in The Cancer Genome Atlas (TCGA) database. However, the role and molecular mechanism of SH3PXD2A-AS1 in NSCLC progression require further exploration. Methods The expression of SH3PXD2A-AS1 in NSCLC and normal lung tissues in a TCGA dataset was analysed by using the GEPIA website. K-M analysis was performed to explore the effects of this molecule on the survival rate in NSCLC. The functional characterization of the role and molecular mechanism of SH3PXD2A-AS1 in NSCLC was performed with a series of in vitro and in vivo experiments. Results SH3PXD2A-AS1 expression was increased in human NSCLC, and high SH3PXD2A-AS1 expression was correlated with poor overall survival. SH3PXD2A-AS1 overexpression sufficiently promoted tumour cell proliferation and accelerated cell cycle progression in vitro and tumour growth in vivo. Moreover, SH3PXD2A-AS1 interacted with DHX9 to enhance FOXM1 expression, promote tumour cell proliferation and accelerate cell cycle progression. Conclusions SH3PXD2A-AS1 promoted NSCLC growth by interacting with DHX9 to enhance FOXM1 expression. SH3PXD2A-AS1 may serve as a promising predictive biomarker for the diagnosis and prognosis of patients with NSCLC.


2007 ◽  
Vol 292 (3) ◽  
pp. C1204-C1215 ◽  
Author(s):  
Kamyar Zahedi ◽  
John J. Bissler ◽  
Zhaohui Wang ◽  
Anuradha Josyula ◽  
Lu Lu ◽  
...  

Expression of spermidine/spermine N1-acetyltransferase (SSAT) increases in kidneys subjected to ischemia-reperfusion injury (IRI). Increased expression of SSAT in vitro leads to alterations in cellular polyamine content, depletion of cofactors and precursors of polyamine synthesis, and reduced cell proliferation. In our model system, a >28-fold increase in SSAT levels in HEK-293 cells leads to depletion of polyamines and elevation in the enzymatic activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase, suggestive of a compensatory reaction to increased polyamine catabolism. Increased expression of SSAT also led to DNA damage and G2 arrest. The increased DNA damage was primarily due to the depletion of polyamines. Other factors such as increased production of H2O2 due to polyamine oxidase activity may play a secondary role in the induction of DNA lesions. In response to DNA damage the ATM/ATR → Chk1/2 DNA repair and cell cycle checkpoint pathways were activated, mediating the G2 arrest in SSAT-expressing cells. In addition, the activation of ERK1 and ERK2, which play integral roles in the G2/M transition, is impaired in cells expressing SSAT. These results indicate that the disruption of polyamine homeostasis due to enhanced SSAT activity leads to DNA damage and reduced cell proliferation via activation of DNA repair and cell cycle checkpoint and disruption of Raf → MEK → ERK pathways. We propose that in kidneys subjected to IRI, one mechanism through which increased expression of SSAT may cause cellular injury and organ damage is through induction of DNA damage and the disruption of cell cycle.


Endocrinology ◽  
2021 ◽  
Author(s):  
Andrea Abate ◽  
Elisa Rossini ◽  
Mariangela Tamburello ◽  
Marta Laganà ◽  
Deborah Cosentini ◽  
...  

Abstract Mitotane is the only approved drug for the treatment of adrenocortical carcinoma (ACC). The regimen to be added to mitotane is a chemotherapy with etoposide, doxorubicin, and cisplatin. This pharmacological approach, however, has a limited efficacy and significant toxicity. Target-therapy agents represent a new promising approach to cancer therapy. Among these, a preeminent role is played by agents that interfere with cell cycle progression, such as CDK4/6-inhibitors. Here, we investigated whether ribociclib could induce a cytotoxic effect both in ACC cell line and patient-derived primary cell cultures, alone or in combined settings. Cell viability was determined by MTT assay while cell proliferation was evaluated by direct count. Binary combination experiments were performed using Chou and Talalay method. Gene expression was analyzed by qRT-PCR while protein expression was evaluated by immunofluorescence. A double staining assay revealed that ribociclib induced a prevalent apoptotic cell death. Cell cycle analysis was performed to evaluate the effect of ribociclib treatment on cell cycle progression in ACC cell models. Our results indicated that ribociclib was cytotoxic and reduced the cell proliferation rate. The effect on cell viability was enhanced when ribociclib was combined with progesterone and/or mitotane. The effect of ribociclib on cell cycle progression revealed a drug-induced cell accumulation in G2 phase. The positive relationship underlined by our results between ribociclib, progesterone and mitotane strengthen the clinical potential of this combination.


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