scholarly journals Transcriptome Profiling of Embryonic Retinal Pigment Epithelium Reprogramming

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 840
Author(s):  
Jared A. Tangeman ◽  
Agustín Luz-Madrigal ◽  
Sutharzan Sreeskandarajan ◽  
Erika Grajales-Esquivel ◽  
Lin Liu ◽  
...  

The plasticity of human retinal pigment epithelium (RPE) has been observed during proliferative vitreoretinopathy, a defective repair process during which injured RPE gives rise to fibrosis. In contrast, following injury, the RPE of the embryonic chicken can be reprogrammed to regenerate neural retina in a fibroblast growth factor 2 (FGF2)-dependent manner. To better explore the mechanisms underlying embryonic RPE reprogramming, we used laser capture microdissection to isolate RNA from (1) intact RPE, (2) transiently reprogrammed RPE (t-rRPE) 6 h post-retinectomy, and (3) reprogrammed RPE (rRPE) 6 h post-retinectomy with FGF2 treatment. Using RNA-seq, we observed the acute repression of genes related to cell cycle progression in the injured t-rRPE, as well as up-regulation of genes associated with injury. In contrast, the rRPE was strongly enriched for mitogen-activated protein kinase (MAPK)-responsive genes and retina development factors, confirming that FGF2 and the downstream MAPK cascade are the main drivers of embryonic RPE reprogramming. Clustering and pathway enrichment analysis was used to create an integrated network of the core processes associated with RPE reprogramming, including key terms pertaining to injury response, migration, actin dynamics, and cell cycle progression. Finally, we employed gene set enrichment analysis to suggest a previously uncovered role for epithelial-mesenchymal transition (EMT) machinery in the initiation of embryonic chick RPE reprogramming. The EMT program is accompanied by extensive, coordinated regulation of extracellular matrix (ECM) associated factors, and these observations together suggest an early role for ECM and EMT-like dynamics during reprogramming. Our study provides for the first time an in-depth transcriptomic analysis of embryonic RPE reprogramming and will prove useful in guiding future efforts to understand proliferative disorders of the RPE and to promote retinal regeneration.

2021 ◽  
Author(s):  
Jared A Tangeman ◽  
Agustín Luz-Madrigal ◽  
Sutharzan Sreeskandarajan ◽  
Erika Grajales- Esquivel ◽  
Lin Liu ◽  
...  

AbstractThe plasticity of human retinal pigment epithelium (RPE) has been observed during proliferative vitreoretinopathy, a defective repair process during which injured RPE gives rise to fibrosis. In contrast, following injury, the RPE of the embryonic chicken can be reprogrammed to regenerate neural retina in an FGF2-dependent manner. To characterize the mechanisms underlying embryonic RPE reprogramming, we used laser capture microdissection to isolate RNA from 1) intact RPE, 2) transiently reprogrammed RPE (t-rRPE) 6 hours post-retinectomy, and 3) reprogrammed RPE (rRPE) 6 hours post-retinectomy with FGF2 treatment. Using RNA-seq, we observed the acute repression of genes related to cell cycle progression in the injured t-rRPE, as well as up-regulation of genes associated with injury. In contrast, the rRPE was strongly enriched for MAPK-responsive genes and retina development factors, confirming that FGF2 and the downstream MAPK cascade are the main drivers of embryonic RPE reprogramming. Clustering and pathway enrichment analysis were used to create an integrated network of the core processes associated with RPE reprogramming, including key terms pertaining to injury response, migration, actin dynamics, and cell cycle progression. Finally, we employed gene set enrichment analysis to suggest a previously uncovered role for epithelial-mesenchymal transition (EMT) machinery in the initiation of embryonic chick RPE reprogramming. The EMT program is accompanied by extensive, coordinated regulation of extracellular matrix (ECM) regulators, and these observations together suggest an early role for ECM and EMT-like dynamics during reprogramming. Our study provides for the first time an in-depth transcriptomic analysis of embryonic RPE reprogramming and will prove useful in guiding future efforts to understand proliferative disorders of the RPE and to promote retinal regeneration.


2020 ◽  
Author(s):  
Dong-Yan Zhang ◽  
Qing-Can Sun ◽  
Xue-Jing Zou ◽  
Yang Song ◽  
Wen-Wen Li ◽  
...  

Abstract Background Dysregulations of lncRNA are responsible for cancer initiation and development, positioning lncRNAs as not only biomarkers but also promising therapeutic targets for cancer treatment. Growing number of lncRNAs have been reported in HCC but their functional and mechanistic roles remain unclear. Methods Gene Set Enrichment Analysis was used to investigate the molecular mechanism of lncRNA UPK1A antisense RNA 1 (UPK1A-AS1). CCK-8 assay, EdU assay, flow cytometry, western blot, and xenograft assay were used to confirm the role of UPK1A-AS1 in proliferation of HCC cells both in vitro and in vivo. Bioinformatics analysis and qRT-PCR were performed to explore the interplay between UPK1A-AS1 and Enhancer of Zeste Homologue 2 (EZH2). RNA immunoprecipitation, RNA-pull down assay, western blot, qRT-PCR, and were conducted to confirm the interaction between UPK1A-AS1 and EZH2. Finally, the expression level and prognosis value of UPK1A-AS1 in HCC were analyzed using RNA-seq data from TCGA datasets. Results We showed that UPK1A-AS1, a newly identified lncRNA, promoted cellular proliferation and tumor growth by accelerating cell cycle progression. Cell cycle related genes including CyclinD1, CDK2, CDK4, CCNB1 and CCNB2 were significantly upregulated in HCC cells with UPK1A-AS1 overexpression. Furthermore, overexpression of UPK1A-AS1 could protect HCC cells from cis-platinum toxicity. Mechanistically, UPK1A-AS1 interacted with EZH2 to mediate its nuclear translocation and reinforce its binding to SUZ12, leading to the increasing trimethylation of H27K3. Targeting EZH2 with specific siRNA impaired UPK1A-AS1-mediated upregulation of proliferation and cell cycle progression related genes. Moreover, UPK1A-AS1 was significantly upregulated in HCC, and upregulation of UPK1A-AS1 predicted poor prognosis for patients with HCC. Conclusions Our study reveals that UPK1A-AS1 promotes HCC development by accelerating cell cycle progression in an EZH2-dependent manner, suggesting that UPK1A-AS1 possesses substantial potential as a novel biomarker for HCC prognosis and therapy.


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.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Ying Wu ◽  
Zhen Li ◽  
Sining Wang ◽  
Aiyuan Xiu ◽  
Chunqing Zhang

Aim. Carvedilol is a nonselective beta-blocker used to reduce portal hypertension. This study investigated the effects and potential mechanisms of carvedilol in angiotensin II- (Ang II-) induced hepatic stellate cell (HSC) proliferation and contraction. Methods. The effect of carvedilol on HSC proliferation was measured by Cell Counting Kit-8 (CCK-8). Cell cycle progression and apoptosis in HSCs were determined by flow cytometry. A collagen gel assay was used to confirm HSC contraction. The extent of liver fibrosis in mice was evaluated by hematoxylin-eosin (H&E) and Sirius Red staining. Western blot analyses were performed to detect the expression of collagen I, collagen III, α-smooth muscle actin (α-SMA), Ang II type I receptor (AT1R), RhoA, Rho-kinase 2 (ROCK2), and others. Results. The results showed that carvedilol inhibited HSC proliferation and arrested the cell cycle at the G0/G1 phase in a dose-dependent manner. Carvedilol also modulated Bcl-2 family proteins and increased apoptosis in Ang II-treated HSCs. Furthermore, carvedilol inhibited HSC contraction induced by Ang II, an effect that was associated with AT1R-mediated RhoA/ROCK2 pathway interference. In addition, carvedilol reduced α-SMA expression and collagen deposition and attenuated liver fibrosis in carbon tetrachloride (CCl4)-treated mice. The in vivo data further confirmed that carvedilol inhibited the expression of angiotensin-converting enzyme (ACE), AT1R, RhoA, and ROCK2. Conclusions. The results indicated that carvedilol dose-dependently inhibited Ang II-induced HSC proliferation by impeding cell cycle progression, thus alleviating hepatic fibrosis. Furthermore, carvedilol could inhibit Ang II-induced HSC contraction by interfering with the AT1R-mediated RhoA/ROCK2 pathway.


Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3051
Author(s):  
Eszter Emri ◽  
Elod Kortvely ◽  
Sascha Dammeier ◽  
Franziska Klose ◽  
David Simpson ◽  
...  

In age-related macular degeneration (AMD), both systemic and local zinc levels decline. Elevation of zinc in clinical studies delayed the progression to end-stage AMD. However, the molecular pathways underpinning this beneficial effect are not yet identified. In this study, we used differentiated primary human fetal retinal pigment epithelium (RPE) cultures and long-term zinc supplementation to carry out a combined transcriptome, proteome and secretome analysis from three genetically different human donors. After combining significant differences, we identified the complex molecular networks using Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA). The cell cultures from the three donors showed extensive pigmentation, development of microvilli and basal infoldings and responded to zinc supplementation with an increase in transepithelial electrical resistance (TEER) (apical supplementation: 443.2 ± 79.3%, basal supplementation: 424.9 ± 116.8%, compared to control: 317.5 ± 98.2%). Significant changes were observed in the expression of 1044 genes, 151 cellular proteins and 124 secreted proteins. Gene set enrichment analysis revealed changes in specific molecular pathways related to cell adhesion/polarity, extracellular matrix organization, protein processing/transport, and oxidative stress response by zinc and identified a key upstream regulator effect similar to that of TGFB1.


2006 ◽  
Vol 173 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Daniela Dorner ◽  
Sylvia Vlcek ◽  
Nicole Foeger ◽  
Andreas Gajewski ◽  
Christian Makolm ◽  
...  

Lamina-associated polypeptide (LAP) 2α is a nonmembrane-bound LAP2 isoform that forms complexes with nucleoplasmic A-type lamins. In this study, we show that the overexpression of LAP2α in fibroblasts reduced proliferation and delayed entry into the cell cycle from a G0 arrest. In contrast, stable down-regulation of LAP2α by RNA interference accelerated proliferation and interfered with cell cycle exit upon serum starvation. The LAP2α-linked cell cycle phenotype is mediated by the retinoblastoma (Rb) protein because the LAP2α COOH terminus directly bound Rb, and overexpressed LAP2α inhibited E2F/Rb-dependent reporter gene activity in G1 phase in an Rb-dependent manner. Furthermore, LAP2α associated with promoter sequences in endogenous E2F/Rb-dependent target genes in vivo and negatively affected their expression. In addition, the expression of LAP2α in proliferating preadipocytes caused the accumulation of hypophosphorylated Rb, which is reminiscent of noncycling cells, and initiated partial differentiation into adipocytes. The effects of LAP2α on cell cycle progression and differentiation may be highly relevant for the cell- and tissue-specific phenotypes observed in laminopathic diseases.


1998 ◽  
Vol 72 (12) ◽  
pp. 9637-9644 ◽  
Author(s):  
Alan K. Howe ◽  
Stéphanie Gaillard ◽  
John S. Bennett ◽  
Kathleen Rundell

ABSTRACT The simian virus 40 small t antigen (small-t) is required for optimal viral replication and transformation, especially during the infection of nondividing cells, suggesting that the function of small-t is to promote cell cycle progression. The mechanism through which small-t promotes cell growth reflects, in part, its binding and inhibition of protein phosphatase 2A (PP2A). The use of recombinant adenoviruses allows small-t expression in a majority of cells in a population, thus providing a convenient source of cells for biochemical analyses. In monkey kidney CV1 cells, small-t expressed from these adenovirus vectors activated the mitogen-activated protein kinase (MAPK) pathway, induced JNK activity, and increased AP-1 DNA-binding activity, all in a PP2A-dependent manner. Expression of small-t also caused an increase in the phosphorylation of the Na+/H+ antiporter, a mitogen-activated ion exchanger whose activity correlates with its phosphorylation. At least part of the antiporter phosphorylation induced by small-t reflected activation of the MAPK pathway, as suggested by results of assays using a chemical inhibitor of the MAPK-activating kinase, MEK. Finally, small-t expression from adenovirus vectors promoted efficient cell cycle progression by growth-arrested cells. These vectors should facilitate further analysis of effects of small-t on cell cycle mediators.


2019 ◽  
Author(s):  
Kamila Burdova ◽  
Hongbin Yang ◽  
Roberta Faedda ◽  
Samuel Hume ◽  
Daniel Ebner ◽  
...  

SummaryCyclins are central engines of cell cycle progression when partnered with Cyclin Dependent Kinases (CDKs). Among the different cyclins controlling cell cycle progression, cyclin F does not partner with a CDK, but forms an E3 ubiquitin ligase, assembling through the F-box domain, an Skp1-Cul1-F-box (SCF) module. Although multiple substrates of cyclin F have been identified the vulnerabilities of cells lacking cyclin F are not known. Thus, we assessed viability of cells lacking cyclin F upon challenging cells with more than 200 kinase inhibitors. The screen revealed a striking synthetic lethality between Chk1 inhibition and cyclin F loss. Chk1 inhibition in cells lacking cyclin F leads to DNA replication catastrophe. The DNA replication catastrophe depends on the accumulation of E2F1 in cyclin F depleted cells. We observe that SCFcyclin F promotes E2F1 degradation after Chk1 inhibitors in a CDK dependent manner. Thus, Cyclin F restricts E2F1 activity during cell cycle and upon checkpoint inhibition to prevent DNA replication stress. Our findings pave the way for patient selection in the clinical use of checkpoint inhibitors.


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