Differential regulation of the TRH gene promoter by triiodothyronine and dexamethasone in pancreatic islets

TRH was initially found in the hypothalamus and regulates TSH secretion. TRH is also produced by insulin-containing beta-cells. Endogenous TRH positively regulates glucagon secretion and attenuates pancreatic exocrine secretion. We have previously shown that triiodothyronine (T(3)) down-regulates pre-pro-TRH gene expression in vivo and in vitro. The present study was designed to determine the initial impact of T(3) on rat TRH gene promoter and to compare this effect with that of dexamethasone (Dex). Primary islet cells and neoplastic cells (HIT T-15 and RIN m5F) were transiently transfected with fragments of the 5'-flanking sequence of TRH fused to the luciferase reporter gene. The persistence of high TRH concentrations in fetal islets in culture, probably due to transactivating factors, allowed us to explore how T(3) and Dex regulate the TRH promoter activity in transfected cells and whether the hormone effect is dependent on the cell type considered. TRH gene promoter activity is inhibited by T(3) in primary but not neoplastic cells and stimulated by Dex in both primary and neoplastic cells of islets. These findings validate previous in vivo and in vitro studies and indicate the transcriptional impact of these hormones on TRH gene expression in the pancreatic islets.

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Functional analysis of haplotypes and promoter activity at the 5' region of the DRD2 gene and associations with schizophrenia.

10.21203/rs.3.rs-15812/v1 ◽

2020 ◽

Author(s):

Xicen Zhang ◽

Mei Ding ◽

Yi Liu ◽

Yongping Liu ◽

Jiaxin Xing ◽

...

Keyword(s):

Gene Expression ◽

Cell Lines ◽

Promoter Region ◽

Regulatory Region ◽

Gene Promoter ◽

Luciferase Reporter ◽

Drd2 Gene ◽

Functional Regions

Abstract Background: In previous studies, we researched the association of the DRD2 gene promoter region SNP loci rs7116768, rs1047479195, rs1799732, rs1799978 and schizophrenia using Sanger sequencing. rs7116768 and rs1799978 were found to be slightly associated with schizophrenia. This study investigated the effects of haplotypes consisted of the four SNPs on protein expression level in vitro and identified the functional sequence in the 5’ regulatory region of DRD2 gene which has a potential link with schizophrenia.Methods: Recombinant plasmids with haplotypes, SNPs and 13 recombinant vectors containing deletion fragments from the DRD2 gene 5' regulatory region were transfected into HEK293 and SK-N-SH cell lines. Relative luciferase activity of the haplotypes, SNPs and different sequences was compared using a dual luciferase reporter assay system.Results: Haplotype H4(G-C-InsC-G) could significantly increase the gene expression in SK-N-SH cell lines. Allele C of rs7116768, allele A of rs1047479195 and allele del C of rs1799732 could up-regulate the gene expression. There were 5~7 functional regions in the promoter region of DRD2 gene that could affect the level of gene expression.Conclusion: We cannot rule out the possibility that different haplotypes may influence DRD2 gene expression in vivo. We observed that allele C of rs7116768, allele A of rs1047479195 and allele del C of rs1799732 could up-regulate gene expression. The truncation results confirmed the existence of functional regions in the promoter region of DRD2 gene that could affect the level of gene expression.

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Calcium Dynamics and Resting Transcriptional Activity Regulates Prolactin Gene Expression

Endocrinology ◽

10.1210/en.2002-220266 ◽

2002 ◽

Vol 143 (9) ◽

pp. 3548-3554 ◽

Cited By ~ 8

Author(s):

Carlos Villalobos ◽

Lucía Núñez ◽

William J. Faught ◽

David C. Leaumont ◽

Fredric R. Boockfor ◽

...

Keyword(s):

Gene Expression ◽

Promoter Activity ◽

Gene Promoter ◽

Luciferase Reporter ◽

Pituitary Cells ◽

Luciferase Reporter Gene ◽

Transcriptional Responses ◽

Prolactin Gene ◽

Before And After ◽

Single Living

Abstract Research on the regulation of hormone gene expression by calcium signaling is hampered by the difficulty of monitoring both parameters within the same individual, living cells. Here we achieved concurrent, dynamic measurements of both intracellular Ca2+ concentration ([Ca2+]i) and prolactin (PRL) gene promoter activity in single, living pituitary cells. Cells were transfected with the luciferase reporter gene under control of the PRL promoter and subjected to bioluminescence and fluorescence imaging before and after presentation of TSH-releasing hormone (TRH), a prototypic regulator of PRL secretion and gene expression that induces a transient Ca2+ release, followed by sustained Ca2+ influx. We found that cells displaying specific photonic emissions (i.e. mammotropes) showed heterogeneous calcium and transcriptional responses to TRH. Transcriptionally responsive cells always exhibited a TRH-induced [Ca2+]i increase. In addition, transcriptional responses were related to the rate of Ca2+ entry but not Ca2+ release. Finally, cells lacking transcriptional responses (but showing [Ca2+]i rises) exhibited larger levels of resting PRL promoter activity than transcriptionally responsive cells. Thus, our results suggest that the sustained entry of Ca2+ induced by TRH (but not the Ca2+ release) regulates transcriptional responsiveness. Superimposed on this regulation, the previous, resting PRL promoter activity also controls transcriptional responses.

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Extrachromosomal circular DNA, microDNA, without canonical promoters produce short regulatory RNAs that suppress gene expression

10.1101/535831 ◽

2019 ◽

Author(s):

Teressa Paulsen ◽

Yoshiyuki Shibata ◽

Pankaj Kumar ◽

Laura Dillon ◽

Anindya Dutta

Keyword(s):

Gene Expression ◽

Promoter Sequence ◽

Luciferase Reporter ◽

Luciferase Reporter Gene ◽

Circular Dna ◽

Endogenous Gene ◽

Mrna Targets ◽

Small Regulatory Rna

ABSTRACTInterest in extrachromosomal circular DNA (eccDNA) molecules has increased recently because of their widespread presence in normal cells across every species ranging from yeast to humans, their increased levels in cancer cells, and their overlap with oncogenic and drug-resistant genes. However, the majority of eccDNA (microDNA) are too small to carry protein coding genes. We have tested functional capabilities of microDNA, by creating artificial microDNA molecules mimicking known microDNA sequences and have discovered that they express functional small regulatory RNA including microRNA and novel si-like RNA. MicroDNA is transcribed in vitro and in vivo independent of a canonical promoter sequence. MicroDNA which carry miRNA genes form transcripts which are processed into mature miRNA molecules, through the endogenous RNA-interference pathway, which repress a luciferase reporter gene as well as endogenous mRNA targets of the miRNA. Further, microDNA containing sequences of exons repress the endogenous gene from which the microDNA was derived through the formation of novel si-like RNA. We also show that endogenous microDNA associate with RNA polymerases subunits POLR2H and POLR3F. Together, these results suggest that microDNA may modulate gene expression through the production of both known and novel regulatory small RNA.

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Impact of RARα and miR-138 on retinoblastoma etoposide resistance

Tumor Biology ◽

10.3233/tub-200072 ◽

2021 ◽

Vol 43 (1) ◽

pp. 11-26

Author(s):

Maike Busch ◽

Natalia Miroschnikov ◽

Jaroslaw Thomas Dankert ◽

Marc Wiesehöfer ◽

Klaus Metz ◽

...

Keyword(s):

Cell Viability ◽

Cell Lines ◽

Cancer Progression ◽

Treated Patient ◽

Luciferase Reporter ◽

Luciferase Reporter Gene ◽

Gene Assay ◽

The Impact

BACKGROUND: Retinoblastoma (RB) is the most common childhood eye cancer. Chemotherapeutic drugs such as etoposide used in RB treatment often cause massive side effects and acquired drug resistances. Dysregulated genes and miRNAs have a large impact on cancer progression and development of chemotherapy resistances. OBJECTIVE: This study was designed to investigate the involvement of retinoic acid receptor alpha (RARα) in RB progression and chemoresistance as well as the impact of miR-138, a potential RARα regulating miRNA. METHODS: RARα and miR-138 expression in etoposide resistant RB cell lines and chemotherapy treated patient tumors compared to non-treated tumors was revealed by Real-Time PCR. Overexpression approaches were performed to analyze the effects of RARα on RB cell viability, apoptosis, proliferation and tumorigenesis. Besides, we addressed the effect of miR-138 overexpression on RB cell chemotherapy resistance. RESULTS: A binding between miR-138 and RARα was shown by dual luciferase reporter gene assay. The study presented revealed that RARα is downregulated in etoposide resistant RB cells, while miR-138 is endogenously upregulated. Opposing RARα and miR-138 expression levels were detectable in chemotherapy pre-treated compared to non-treated RB tumor specimen. Overexpression of RARα increases apoptosis levels and reduces tumor cell growth of aggressive etoposide resistant RB cells in vitro and in vivo. Overexpression of miR-138 in chemo-sensitive RB cell lines partly enhances cell viability after etoposide treatment. CONCLUSIONS: Our findings show that RARα acts as a tumor suppressor in retinoblastoma and is downregulated upon etoposide resistance in RB cells. Thus, RARα may contribute to the development and progression of RB chemo-resistance.

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LINC00839 Knockdown Restrains The Metastatic Behaviors of Nasopharyngeal Carcinoma By Sponging miR-454-3p

10.21203/rs.3.rs-606939/v1 ◽

2021 ◽

Author(s):

Feng Ying Zhang ◽

Xia Li ◽

Ting Ting Huang ◽

Mei Ling Xiang ◽

Lin Lin Sun ◽

...

Keyword(s):

Nasopharyngeal Carcinoma ◽

Underlying Mechanism ◽

Luciferase Reporter ◽

Regulatory Function ◽

Migration And Invasion ◽

Luciferase Reporter Gene ◽

Non Coding Rna ◽

Invasive Capacity

Abstract Background Long intergenic non-coding RNA 00839 (LINC00839) has been verified as a cancer-promoting gene in malignancies. However, the significance of LINC00839 in nasopharyngeal carcinoma (NPC) has yet to be elaborated, as well as its underlying mechanism.Methods LINC00839 and miR-454-3p relative expression levels in NPC cells were examined by qRT-PCR. The growth of cells was examined by CCK-8 and colony formation assays. Cell migration and invasion were examined by wound healing and Transwell experiment, respectively. The binding sequence of LINC00839 and miR-454-3p was confirmed by the luciferase reporter gene experiment. The regulatory function of LINC00839 and miR-454-3p on c-Met was investigated by western blot.Results Here, we revealed that LINC00839 was elevated in NPC. Both LINC00839 knockdown and upregulation of miR-454-3p suppressed NPC cells proliferation, invasive capacity and EMT in vitro. Besides, LINC00839 was validated as a miR-454-3p “sponge”, and upregulation of LINC00839 could reverse miR-454-3p-mediated functions in NPC C666-1 and SUNE-1 cells. Furthermore, c-Met was determined to be targeted by miR-454-3p. Notably, c-Met was downregulated by LINC00839 knockdown through sponging miR-454-3p. In vivo, LINC00839 knockdown resulted in a slower tumor growth.Conclusions Altogether, knockdown of LINC00839 inhibits the aggressive properties of NPC cells via sponging miR-454-3p and regulating c-Met.

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Circular RNA CDR1as Inhibits the Metastasis of Gastric Cancer through Targeting miR-876-5p/GNG7 Axis

Gastroenterology Research and Practice ◽

10.1155/2021/5583029 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Jiajia Jiang ◽

Rong Li ◽

Junyi Wang ◽

Jie Hou ◽

Hui Qian ◽

...

Keyword(s):

Gastric Cancer ◽

Epithelial Mesenchymal Transition ◽

Circular Rna ◽

Luciferase Reporter ◽

Migration And Invasion ◽

Luciferase Reporter Gene ◽

Mesenchymal Transition ◽

Underlying Mechanisms

Circular RNA CDR1as has been demonstrated to participate in various cancer progressions as miRNA sponges. The exact underlying mechanisms of CDR1as on gastric cancer (GC) metastasis remain unknown. Here, we found that CDR1as knockdown facilitated GC cell migration and invasion while its overexpression inhibited the migration and invasion abilities of GC cells in vitro and in vivo. Moreover, epithelial-mesenchymal transition- (EMT-) associated proteins and MMP2 and MMP9 were downregulated by CDR1as. Bioinformatics analysis combined with dual-luciferase reporter gene assays, western blot, RT-qPCR analysis, and functional rescue experiments demonstrated that CDR1as served as a miR-876-5p sponge and upregulated the target gene GNG7 expression to suppress GC metastasis. In summary, our findings indicate that CDR1as suppresses GC metastasis through the CDR1as/miR-876-5p/GNG7 axis.

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Phospholipase A 2 Metabolites Mediate Endothelin Stimulation of the Human Brain Natriuretic Peptide Promoter

Hypertension ◽

10.1161/hyp.36.suppl_1.721-b ◽

2000 ◽

Vol 36 (suppl_1) ◽

pp. 721-721

Author(s):

Quan He

Keyword(s):

Gene Expression ◽

Brain Natriuretic Peptide ◽

Natriuretic Peptide ◽

Promoter Activity ◽

Luciferase Activity ◽

Phospholipase A ◽

Luciferase Reporter ◽

Luciferase Reporter Gene ◽

P450 Monooxygenase ◽

Stimulation Of

P155 Brain natriuretic peptide (BNP) gene expression accompanies cardiac hypertrophy and heart failure. The vasoconstrictor endothelin-1 (ET)may be involved in the development of these diseases. ET has also been shown to activate phospholipase A 2 (PLA 2 ). Thus we studied whether ET and PLA 2 metabolites regulate BNP gene expression. The hBNP promoter (-1818 to + 100) coupled to a luciferase reporter gene was transferred into neonatal ventricular myocytes (NVM),and luciferase activity was measured as an index of promoter activity. ET (10 -7 M)induced BNP mRNA in NVM as assessed by Northern blot. It also stimulated the hBNP promoter 4-fold vs control, an effect completely inhibited by actinomycin D. To test the involvement of different PLA 2 isoforms, transfected cells were treated with the Ca ++ -independent PLA 2 (iPLA 2 )inhibitor bromoenol lactone (BEL), the cytosolic PLA 2 inhibitor methyl arachidonyl fluorophosphonate, or the secretory PLA 2 inhibitor ONO-RS-082 prior to stimulation with ET. Only the iPLA 2 inhibitor BEL prevented ET-stimulated hBNP promoter activity. The PLA 2 metabolite lysophosphatidic acid (LPA) also activated the hBNP promoter (2.2-fold; n = 3), but lysophosphatidylcholine did not. To test whether arachidonic acid metabolites are involved in ET’s effect, cells were pretreated with either a lipoxygenase (LO), cyclooxygenase, or p450 monooxygenase inhibitor. Only the LO inhibitor baicalein prevented ET stimulation of the hBNP promoter. Finally, we studied the involvement of cis elements in ET-stimulated hBNP promoter activity. Deletion of BNP promoter sequences from -1818 to -408 and from -408 to -40 reduced ET’s effect by 54% and 78%, respectively. Moreover, ET-stimulated luciferase activity was reduced by 53% when the GATA element (at position -85 relative to the start site of transcription) was mutated. These data suggest that: 1) ET activates the hBNP promoter through a transcriptional mechanism; 2) LPA, perhaps generated by a BEL-sensitive iPLA 2 , is involved in ET’s effect; 3) a LO pathway may also mediate ET signaling; and 4) ET regulation of the hBNP promoter targets both distal and proximal cis elements, including GATA.

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In vivo regulation of β-MHC gene in rodent heart: role of T3 and evidence for an upstream enhancer

AJP Cell Physiology ◽

10.1152/ajpcell.1999.276.4.c883 ◽

1999 ◽

Vol 276 (4) ◽

pp. C883-C891 ◽

Cited By ~ 46

Author(s):

Carola E. Wright ◽

F. Haddad ◽

A. X. Qin ◽

P. W. Bodell ◽

K. M. Baldwin

Keyword(s):

Gene Expression ◽

Thyroid Hormone ◽

Reporter Gene ◽

Normal Control ◽

Transcriptional Activity ◽

Luciferase Reporter ◽

Luciferase Reporter Gene ◽

Promoter Construct ◽

Hormone Responsiveness

Cardiac β-myosin heavy chain (β-MHC) gene expression is mainly regulated through transcriptional processes. Although these results are based primarily on in vitro cell culture models, relatively little information is available concerning the interaction of key regulatory factors thought to modulate MHC expression in the intact rodent heart. Using a direct gene transfer approach, we studied the in vivo transcriptional activity of different-length β-MHC promoter fragments in normal control and in altered thyroid states. The test β-MHC promoter was fused to a firefly luciferase reporter gene, whereas the control α-MHC promoter was fused to the Renilla luciferase reporter gene and was used to account for variations in transfection efficiency. Absolute reporter gene activities showed that β- and α-MHC genes were individually and reciprocally regulated by thyroid hormone. The β-to-α ratios of reporter gene expression demonstrated an almost threefold larger β-MHC gene expression in the longest than in the shorter promoter fragments in normal control animals, implying the existence of an upstream enhancer. A mutation in the putative thyroid response element of the −408-bp β-MHC promoter construct caused transcriptional activity to drop to null. When studied in the −3,500-bp β-MHC promoter, construct activity was reduced (∼100-fold) while thyroid hormone responsiveness was retained. These findings suggest that, even though the bulk of the thyroid hormone responsiveness of the gene is contained within the first 215 bp of the β-MHC promoter sequence, the exact mechanism of triiodothyronine (T3) action remains to be elucidated.

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CircRNA_0092516 regulates chondrocyte proliferation and apoptosis in osteoarthritis through the miR-337-3p/PTEN axis

The Journal of Biochemistry ◽

10.1093/jb/mvaa119 ◽

2020 ◽

Author(s):

Zhihui Huang ◽

Wenming Ma ◽

Jinhuai Xiao ◽

Xiaoyu Dai ◽

Weiqi Ling

Keyword(s):

Cell Apoptosis ◽

Luciferase Reporter ◽

Circular Rnas ◽

Mechanism Analysis ◽

Potential Mechanism ◽

Luciferase Reporter Gene ◽

Chondrocyte Proliferation ◽

In Vivo Experiments

Abstract The dysregulation of circular RNAs (circRNAs) has been identified in various human diseases. Here, we probed into the potential mechanism of circRNA_0092516 in osteoarthritis (OA). The expression of circRNA_0092516 was tested by quantitative real-time PCR. MTT, flow cytometry and western blot were applied to confirm the functions of circRNA_0092516 in vitro. Besides, RNA pull-down and dual-luciferase reporter gene experiments were applied to probe into the mechanism. circRNA_0092516 was raised in the tissues of OA patients and chondrocytes stimulated by IL-1β. The potential mechanism analysis expounded that circRNA_0092516 bound to miR-337-3p, and the interference with circRNA_0092516 boosted chondrocyte proliferation and restrained cell apoptosis through the miR-337-3p/phosphatase and tensin homolog (PTEN) axis, thereby improving OA. In-vivo experiments expounded that circRNA_0092516 regulated cartilage production through miR-337-3p. Overall, our data expounded that the interference with circRNA_0092516 boosted chondrocyte proliferation and restrained cell apoptosis through the miR-337-3p/PTEN axis, eventually slowed down the progress of OA.

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MKL-1 regulates the stem cell marker. CD44 in breast cancer cells

E3S Web of Conferences ◽

10.1051/e3sconf/20197801002 ◽

2019 ◽

Vol 78 ◽

pp. 01002

Author(s):

Zhou-Tong Dai ◽

Ao Yao ◽

Yuan Xiang ◽

Jia Peng Li ◽

Wei Guo ◽

...

Keyword(s):

Gene Expression ◽

Malignant Tumors ◽

Regulation Of Gene Expression ◽

Gene Promoter ◽

Expression Regulation ◽

Stem Cell Marker ◽

Luciferase Reporter ◽

Regulation Mechanism ◽

Luciferase Reporter Gene ◽

Factors Affecting

CD44, cluster of differentiation 44 is a typical marker of stem cells. At present, it has been found that CD44 is prevalent in various human malignant tumors, but its expression regulation mechanism is still not clear. The initiation of gene expression, the modification of RNA levels, and the regulation of protein levels are the main factors affecting the expression level of genes, and the most critical one is the regulation of gene expression by signaling pathways. Up to now, there has been no report on the role of MKL-1 in the cloning of the cd44 promoter. Therefore, this study intends to clone the cd44 gene promoter, construct its luciferase reporter gene vector, transfect the MKL-1 overexpression vector, and analyze how it affects transcriptional activity, in order to further study the expression regulation of cd44. The mechanism provides a powerful tool in the future.

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