PIT1 upregulation by HMGA proteins has a role in pituitary tumorigenesis

2011 ◽  
Vol 19 (2) ◽  
pp. 123-135 ◽  
Author(s):  
Dario Palmieri ◽  
Teresa Valentino ◽  
Ivana De Martino ◽  
Francesco Esposito ◽  
Paolo Cappabianca ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Gene Promoter ◽  
Pituitary Tumour ◽  
Human Pituitary ◽  
Expression Levels ◽  
Pituitary Tumorigenesis ◽  
Its Gene ◽  
Gland Development

We have previously demonstrated that HMGA1B and HMGA2 overexpression in mice induces the development of GH and prolactin (PRL) pituitary adenomas mainly by increasing E2F1 transcriptional activity. Interestingly, these adenomas showed very high expression levels of PIT1, a transcriptional factor that regulates the gene expression ofGh,Prl,GhrhrandPit1itself, playing a key role in pituitary gland development and physiology. Therefore, the aim of our study was to identify the role ofPit1overexpression in pituitary tumour development induced by HMGA1B and HMGA2. First, we demonstrated that HMGA1B and HMGA2 directly interact with both PIT1 and its gene promoterin vivo, and that these proteins positively regulatePit1promoter activity, also co-operating with PIT1 itself. Subsequently, we showed, by colony-forming assays on two different pituitary adenoma cell lines, GH3 and αT3, thatPit1overexpression increases pituitary cell proliferation. Finally, the expression analysis ofHMGA1,HMGA2andPIT1in human pituitary adenomas of different histological types revealed a direct correlation betweenPIT1and HMGA expression levels. Taken together, our data indicate a role ofPit1upregulation by HMGA proteins in pituitary tumours.

scholarly journals Cerebrospinal Fluid Pulsation Stress Promotes the Angiogenesis of Tissue-Engineered Laminae

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Linli Li ◽  
Yiqun He ◽  
Han Tang ◽  
Wei Mao ◽  
Haofei Ni ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cerebrospinal Fluid ◽  
Engineering Technology ◽  
Expression Levels ◽  
Fluid Pulsation ◽  
Endothelial Growth Factor ◽  
The Impact

Background. Angiogenesis is a prerequisite step to achieve the success of bone regeneration by tissue engineering technology. Previous studies have shown the role of cerebrospinal fluid pulsation (CSFP) stress in the reconstruction of tissue-engineered laminae. In this study, we investigated the role of CSFP stress in the angiogenesis of tissue-engineered laminae. Methods. For the in vitro study, a CSFP bioreactor was used to investigate the impact of CSFP stress on the osteogenic mesenchymal stem cells (MSCs). For the in vivo study, forty-eight New Zealand rabbits were randomly divided into the CSFP group and the Non-CSFP group. Tissue-engineered laminae (TEL) was made by hydroxyapatite-collagen I scaffold and osteogenic MSCs and then implanted into the lamina defect in the two groups. The angiogenic and osteogenic abilities of newborn laminae were examined with histological staining, qRT-PCR, and radiological analysis. Results. The in vitro study showed that CSFP stress could promote the vascular endothelial growth factor A (VEGF-A) expression levels of osteogenic MSCs. In the animal study, the expression levels of angiogenic markers in the CSFP group were higher than those in the Non-CSFP group; moreover, in the CSFP group, their expression levels on the dura mater surface, which are closer to the CSFP stress stimulation, were also higher than those on the paraspinal muscle surface. The expression levels of osteogenic markers in the CSFP group were also higher than those in the Non-CSFP group. Conclusion. CSFP stress could promote the angiogenic ability of osteogenic MSCs and thus promote the angiogenesis of tissue-engineered laminae. The pretreatment of osteogenic MSC with a CSFP bioreactor may have important implications for vertebral lamina reconstruction with a tissue engineering technique.

scholarly journals Expression of bovine superoxide dismutase in Drosophila melanogaster augments resistance of oxidative stress.

1991 ◽  
Vol 11 (2) ◽  
pp. 632-640 ◽  
Author(s):  
I Reveillaud ◽  
A Niedzwiecki ◽  
K G Bensch ◽  
J E Fleming
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Promoter ◽  
Adult Mortality ◽  
P Elements ◽  
Transgenic Lines ◽  
A Minor ◽  
Radical Damage ◽  
Positive Effect

Superoxide dismutases (SOD) play a major role in the intracellular defense against oxygen radical damage to aerobic cells. In eucaryotes, the cytoplasmic form of the enzyme is a 32-kDa dimer containing two copper and two zinc atoms (CuZn SOD) that catalyzes the dismutation of the superoxide anion (O2-) to H2O2 and O2. Superoxide-mediated damage has been implicated in a number of biological processes, including aging and cancer; however, it is not certain whether endogenously elevated levels of SOD will reduce the pathological events resulting from such damage. To understand the in vivo relationship between an efficient dismutation of O2- and oxidative injury to biological structures, we generated transgenic strains of Drosophila melanogaster overproducing CuZn SOD. This was achieved by microinjecting Drosophila embryos with P-elements containing bovine CuZn SOD cDNA under the control of the Drosophila actin 5c gene promoter. Adult flies of the resulting transformed lines which expressed both mammalian and Drosophila CuZn SOD were then used as a novel model for evaluating the role of oxygen radicals in aging. Our data show that expression of enzymatically active bovine SOD in Drosophila flies confers resistance to paraquat, an O2(-)-generating compound. This is consistent with data on adult mortality, because there was a slight but significant increase in the mean lifespan of several of the transgenic lines. The highest level of expression of the active enzyme in adults was 1.60 times the normal value. Higher levels may have led to the formation of toxic levels of H2O2 during development, since flies that died during the process of eclosion showed an unusual accumulation of lipofuscin (age pigment) in some of their cells. In conclusion, our data show that free-radical detoxification has a minor by positive effect on mean longevity for several strains.

scholarly journals Foxa3 (HNF-3γ) binds to and activates the rat proglucagon gene promoter but is not essential for proglucagon gene expression

2002 ◽  
Vol 366 (2) ◽  
pp. 633-641 ◽  
Author(s):  
Yuanfang LIU ◽  
Wei SHEN ◽  
Patricia L. BRUBAKER ◽  
Klaus H. KAESTNER ◽  
Daniel J. DRUCKER
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Promoter Activity ◽  
Gene Promoter ◽  
Forkhead Box ◽  
Mild Hypoglycaemia ◽  
Element Binding Protein ◽  
Prolonged Fast

Members of the Forkhead box a (Foxa) transcription factor family are expressed in the liver, pancreatic islets and intestine and both Foxa1 and Foxa2 regulate proglucagon gene transcription. As Foxa proteins exhibit overlapping DNA-binding specificities, we examined the role of Foxa3 [hepatocyte nuclear factor (HNF)-3γ] in control of proglucagon gene expression. Foxa3 was detected by reverse transcriptase PCR in glucagon-producing cell lines and binds to the rat proglucagon gene G2 promoter element in GLUTag enteroendocrine cells. Although Foxa3 increased rat proglucagon promoter activity in BHK fibroblasts, augmentation of Foxa3 expression did not increase proglucagon promoter activity in GLUTag cells. Furthermore, adenoviral Foxa3 expression did not affect endogenous proglucagon gene expression in islet or intestinal endocrine cell lines. Although Foxa3-/- mice exhibit mild hypoglycaemia during a prolonged fast, the levels of proglucagon-derived peptides and proglucagon mRNA transcripts were comparable in tissues from wild-type and Foxa3-/- mice. These findings identify Foxa3 as a member of the proglucagon gene G2 element binding-protein family that, unlike Foxa1, is not essential for control of islet or intestinal proglucagon gene expression in vivo.

scholarly journals Role of NF-Y in In Vivo Regulation of the γ-Globin Gene

2001 ◽  
Vol 21 (9) ◽  
pp. 3083-3095 ◽  
Author(s):  
Zhijun Duan ◽  
George Stamatoyannopoulos ◽  
Qiliang Li
Keyword(s):  
Globin Gene ◽  
Gene Promoter ◽  
Transcriptional Factor ◽  
Proximal Promoter ◽  
Transcription Cofactor ◽  
Basal Transcriptional Machinery ◽  
Ccaat Box ◽  
Chromatin Opening

ABSTRACT The duplicated CCAAT box is required for γ gene expression. We report here that the transcriptional factor NF-Y is recruited to the duplicated CCAAT box in vivo. A mutation of the duplicated CCAAT box that severely disrupts the NF-Y binding also reduces the accessibility level of the γ gene promoter, affects the assembly of basal transcriptional machinery, and increases the recruitment of GATA-1 to the locus control region (LCR) and the proximal promoter and the recruitment of transcription cofactor CBP/p300 to the LCR. These findings suggest that recruitment of NF-Y to the duplicated CCAAT box plays a role in the chromatin opening of the γ gene promoter as well as in the communication between the γ gene promoter and the LCR.

scholarly journals The Role of Pseudo-Orthocaspase (SyOC) of Synechocystis sp. PCC 6803 in Attenuating the Effect of Oxidative Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Saul Lema A ◽  
Marina Klemenčič ◽  
Franziska Völlmy ◽  
Maarten Altelaar ◽  
Christiane Funk
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Building Blocks ◽  
Amino Acid Residues ◽  
Knock Out ◽  
Functional Homology ◽  
Its Gene ◽  
Pcc 6803

Caspases are proteases, best known for their involvement in the execution of apoptosis—a subtype of programmed cell death, which occurs only in animals. These proteases are composed of two structural building blocks: a proteolytically active p20 domain and a regulatory p10 domain. Although structural homologs appear in representatives of all other organisms, their functional homology, i.e., cell death depending on their proteolytical activity, is still much disputed. Additionally, pseudo-caspases and pseudo-metacaspases, in which the catalytic histidine-cysteine dyad is substituted with non-proteolytic amino acid residues, were shown to be involved in cell death programs. Here, we present the involvement of a pseudo-orthocaspase (SyOC), a prokaryotic caspase-homolog lacking the p10 domain, in oxidative stress in the model cyanobacterium Synechocystis sp. PCC 6803. To study the in vivo impact of this pseudo-protease during oxidative stress its gene expression during exposure to H2O2 was monitored by RT-qPCR. Furthermore, a knock-out mutant lacking the pseudo-orthocaspase gene was designed, and its survival and growth rates were compared to wild type cells as well as its proteome. Deletion of SyOC led to cells with a higher tolerance toward oxidative stress, suggesting that this protein may be involved in a pro-death pathway.

scholarly journals The enzyme succinate dehydrogenase (SDH) and its role in hereditary pituitary adenomas

2013 ◽  
Vol 10 (4) ◽  
pp. 10-15
Author(s):  
Iu V Pankratova ◽  
E G Przhiyalkovskaya ◽  
E A Pigarova ◽  
L K Dzeranova
Keyword(s):  
Pituitary Adenomas ◽  
Multiple Endocrine Neoplasia ◽  
Germline Mutations ◽  
Genetic Defects ◽  
Hereditary Syndromes ◽  
Pituitary Tumorigenesis ◽  
Active Research ◽  
Familial Pituitary Adenomas

Despite active research involving familial pituitary adenomas and characterization of five hereditary syndromes, the genetic defects in more than 80 - 95% of patients remain not found. Besides, there is more than 25 cases of coexistence of pheochromocytomas and pituitary adenomas described in literature that up to date is not integrated in any syndrome; genetic defects of such coexistence also aren't defined. However it is supposed that in pituitary tumorigenesis, germline mutations of SDH can take part that is obviously important aspect of further investigation. Germline mutations of SDH were found in patients with different phenotypes of pituitary adenomas. Studying of mutations in genes SDHD, SDHB, SDHC, SDHA and their prevalence in patients with familial pituitary adenomas or with phenotypes of multiple endocrine neoplasia without mutations in MEN1, CDKN1B, PRKAR1A, AIP genes can provide clarity in a role of mutations in SDH in endocrine and in particular pituitary tumorigenesis.

scholarly journals Curcumin acts as anti-tumorigenic and hormone-suppressive agent in murine and human pituitary tumour cells in vitro and in vivo

2009 ◽  
Vol 16 (4) ◽  
pp. 1339-1350 ◽  
Author(s):  
C Schaaf ◽  
B Shan ◽  
M Buchfelder ◽  
M Losa ◽  
J Kreutzer ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Lines ◽  
Tumour Cell ◽  
Curcuma Longa ◽  
Pituitary Tumour ◽  
Pituitary Cells ◽  
Facs Analysis ◽  
Human Pituitary ◽  
Tumour Cell Lines

Curcumin (diferuloylmethane) is the active ingredient of the spice plant Curcuma longa and has been shown to act anti-tumorigenic in different types of tumours. Therefore, we have studied its effect in pituitary tumour cell lines and adenomas. Proliferation of lactosomatotroph GH3 and somatotroph MtT/S rat pituitary cells as well as of corticotroph AtT20 mouse pituitary cells was inhibited by curcumin in monolayer cell culture and in colony formation assay in soft agar. Fluorescence-activated cell sorting (FACS) analysis demonstrated curcumin-induced cell cycle arrest at G2/M. Analysis of cell cycle proteins by immunoblotting showed reduction in cyclin D1, cyclin-dependent kinase 4 and no change in p27kip. FACS analysis with Annexin V-FITC/7-aminoactinomycin D staining demonstrated curcumin-induced early apoptosis after 3, 6, 12 and 24 h treatment and nearly no necrosis. Induction of DNA fragmentation, reduction of Bcl-2 and enhancement of cleaved caspase-3 further confirmed induction of apoptosis by curcumin. Growth of GH3 tumours in athymic nude mice was suppressed by curcumin in vivo. In endocrine pituitary tumour cell lines, GH, ACTH and prolactin production were inhibited by curcumin. Studies in 25 human pituitary adenoma cell cultures have confirmed the anti-tumorigenic and hormone-suppressive effects of curcumin. Altogether, the results described in this report suggest this natural compound as a good candidate for therapeutic use on pituitary tumours.

scholarly journals SIRT1 Promotes Cell Survival under Stress by Deacetylation-Dependent Deactivation of Poly(ADP-Ribose) Polymerase 1

2009 ◽  
Vol 29 (15) ◽  
pp. 4116-4129 ◽  
Author(s):  
Senthilkumar B. Rajamohan ◽  
Vinodkumar B. Pillai ◽  
Madhu Gupta ◽  
Nagalingam R. Sundaresan ◽  
Konstantin G. Birukov ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Cell Survival ◽  
Cross Talk ◽  
Gene Promoter ◽  
Stress Conditions ◽  
Transcriptional Level ◽  
A Cell

ABSTRACT Poly(ADP-ribose) polymerase 1 (PARP1) and SIRT1 deacetylase are two NAD-dependent enzymes which play major roles in the decision of a cell to live or to die in a stress situation. Because of the dependence of both enzymes on NAD, cross talk between them has been suggested. Here, we show that PARP1 is acetylated after stress of cardiomyocytes, resulting in the activation of PARP1, which is independent of DNA damage. SIRT1 physically binds to and deacetylates PARP1. Increased acetylation of PARP1 was also detected in hearts of SIRT1−/− mice, compared to that detected in the hearts of SIRT1+/+ mice, confirming a role of SIRT1 in regulating the PARP1 acetylation in vivo. SIRT1-dependent deacetylation blocks PARP1 activity, and it protects cells from PARP1-mediated cell death. We also show that SIRT1 negatively regulates the activity of the PARP1 gene promoter, thus suggesting that the deacetylase controls the PARP1 activity at the transcriptional level as well. These data demonstrate that the activity of PARP1 is under the control of SIRT1, which is necessary for survival of cells under stress conditions.

scholarly journals MiR-148b, MiR-152/ALCAM Axis Regulates the Proliferation and Invasion of Pituitary Adenomas Cells

2017 ◽  
Vol 44 (2) ◽  
pp. 792-803 ◽  
Author(s):  
Wei He ◽  
Ling Huang ◽  
Min Li ◽  
Yue Yang ◽  
Zhen Chen ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Target Genes ◽  
Annexin V ◽  
Expression Level ◽  
Human Pituitary ◽  
Aberrant Expression ◽  
Leukocyte Antigen ◽  
Noninvasive Samples ◽  
Proliferation And Invasion

Background/Aims: Aberrant expression of miRNA has been found in many tumor tissues to regulate the tumorigenesis by binding to the 3`- untranslated region (3`-UTR) of the target genes. The aim of this study is to investigate the role of miR-148b, miR-152/ALCAM axis in human pituitary adenomas (PAs). Methods: First, we detected the expression level of miR-148b-3p and miR-152 in human PAs samples by using qRT-PCR. Then we studied the role of miR-148b-3p, miR-152 on human PAs cell proliferation, invasion and apoptosis by using MTS assay, Transwell invasion assay and Annexin V/PI Staining Test. To study the relationship between miR-148b-3p, miR-152 and activated leukocyte antigen molecule (ALCAM), we overexpressed miR-148-3p or miR-152 by transfecting specific mimics. Lucifearase reporter assay was then performed to confirm the target. Next, we studied the biological functions of ALCAM in human PAs cells. Finally, the role of miR-148b-3p, miR-152/ALCAM axis in PAs cells was studied. Results: The expression level of miR-148-3p and miR-152 in invasive PAs samples was lower than those in noninvasive samples. Overexpression of miR-148b-3p, miR-152 could repress proliferation and invasion, and promote apoptosis. Moreover, miR-148b-3p and miR-152 could repress activated leukocyte antigen molecule (ALCAM) expression. Knockdown of ALCAM could repress proliferation and invasion and promote apoptosis. By contrary, overexpression of ALCAM promoted proliferation and invasion. Further, the rescue experiments indicated that overexpression of ALCAM significantly restored the proliferation, apoptosis, and invasion influenced by miR-148b-3p and miR-152. Conclusions: Our study suggests that miR-148b-3p, miR-152 may serve as suppressors in PAs through downregulating ALCAM expression. miR-148b, miR-152/ ALCAM axis may be a new therapeutic target in the future.

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