scholarly journals GDF-9 and BMP-15 mRNA Levels in Canine Cumulus Cells Related to Cumulus Expansion and the Maturation Process

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 462 ◽  
Author(s):  
George Ramirez ◽  
Jaime Palomino ◽  
Karla Aspee ◽  
Monica De los Reyes
Keyword(s):  
Gene Expression ◽  
Estrous Cycle ◽  
Expression Patterns ◽  
Cumulus Cells ◽  
Mrna Levels ◽  
Cumulus Expansion ◽  
Polymerase Chain ◽  
Specific Regulation ◽  
Reproductive Phases

The competence to undergo expansion is a characteristic of cumulus cells (CCs). The aim was to investigate the expression of GDF-9 and BMP-15 mRNA in canine cumulus cells in relation to cumulus expansion and meiotic development over the estrous cycle. CCs were recovered from nonmatured and in vitro-matured (IVM) dog cumulus oocyte complexes (COCs), which were obtained from antral follicles at different phases of the estrous cycle. Quantitative real-time polymerase chain reaction (q-PCR) was used to evaluate the relative abundance of GDF-9 and BMP-15 transcripts from the CCs with or without signs of expansion. The results were evaluated by ANOVA and logistic regression. The maturity of the oocyte and the expansion process affected the mRNA levels in CCs. There were differences (p < 0.05) in GDF-9 and BMP-15 gene expression in CCs isolated from nonmatured COCs when comparing the reproductive phases. Lower mRNA levels (p < 0.05) were observed in anestrus and proestrus in comparison to those in estrus and diestrus. In contrast, when comparing GDF-9 mRNA levels in IVM COCs, no differences were found among the phases of the estrous cycle in expanded and nonexpanded CCs (p < 0.05). However, the highest (p < 0.05) BMP-15 gene expression in CCs that did not undergo expansion was exhibited in anestrus and the lowest (p < 0.05) expression was observed in estrus in expanded CCs. Although the stage of the estrous cycle did not affect the second metaphase (MII )rates, the expanded CCs obtained at estrus coexisted with higher percentages of MII (p < 0.05). In conclusion, the differential expression patterns of GDF-9 and BMP-15 mRNA transcripts might be related to cumulus expansion and maturation processes, suggesting specific regulation and temporal changes in their expression.

60 EFFECTS OF AY9944 A-7 ON MEIOTIC RESUMPTION OF PORCINE OOCYTES AND CUMULUS CELL EXPANSION

2016 ◽  
Vol 28 (2) ◽  
pp. 160
Author(s):  
S. Lee ◽  
C. Khoirinaya ◽  
J.-X. Jin ◽  
G. A. Kim ◽  
B.-C. Lee
Keyword(s):  
Gene Expression ◽  
Oocyte Maturation ◽  
Cell Expansion ◽  
Cholesterol Biosynthesis ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Mitogen Activated Protein Kinase ◽  
Control Group ◽  
Cumulus Expansion

In vitro studies on mammalian oocytes have shown that follicular fluid-meiosis activating sterol (FF-MAS) can overcome the inhibitory effect of hypoxanthine (Hx) on the resumption of meiosis. FF-MAS, an intermediate in the cholesterol biosynthesis pathway, is converted to testis meiosis–activating sterol by a sterol Δ14-reductase. AY9944 A-7, an inhibitor of Δ14-reductase and Δ7-reductase, induces accumulation of FF-MAS by inhibiting its metabolism. The aim of this study was to evaluate the effects of AY9944 A-7 on meiotic resumption of porcine oocytes, cumulus cell expansion, and gene expression related to M-phase-promoting factor (MPF), mitogen-activated protein kinase (MAPK), and oocyte maturation in oocytes and related to cumulus expansion in cumulus cells. In experiment 1, 1136 cumulus-oocyte complexes (COCs) were cultured in IVM media with 4 different concentrations (0, 10, 20, and 40 μM) of AY9944 A-7 in addition to a meiotic inhibitor (Hx, 4 mM) for 44 h. Oocytes treated with 10 and 20 μM AY9944 A-7 in the presence of Hx had significantly higher GVBD and M2 rates than the control group. However, 40 μM AY9944 A-7 significantly decreased GVBD and M2 rates and increased degeneration of oocytes compared with other groups. In experiment 2, 600 COCs were cultured in IVM media with 4 different concentrations (0, 10, 20, and 40 μM) of AY9944 A-7 in the absence of Hx for 44 h. Cumulus expansion of 40 μM AY9944 A-7 treated group was significantly decreased compared with other groups. In experiment 3, we evaluate the effects of AY9944 A-7 on gene expression, and the experiment was replicated four times. Data on gene expression were analysed using Student’s t-test. Oocytes treated with 10 μM AY9944 A-7 increased expression of genes involved in MPF (Cyclin B and Cdc2), MAPK (C-mos), and oocyte maturation (GDF9 and BMP15). Cumulus cells treated with 10 μM AY9944 A-7 decreased cumulus expansion-related genes (Has2, Tnfaip6, Ptgs2, and Ptx-3). In conclusion, our results suggest that although 10 μM AY9944 A-7 decreased cumulus expansion-related genes, there was no difference in cumulus expansion and it induced meiotic resumption of porcine oocytes with increased MPF, MAPK, and oocyte maturation-related genes. Further studies are needed to evaluate the effect of AY9944 A-7 on porcine embryo development. This study was supported by Ministry Of Trade, Industry & Energy (#10048948), Korea IPET (#114059–3), Research Institute for Veterinary Science, TS Corporation, and the BK21 plus program.

Gene and protein expression of connexins 37 and 43 in cumulus–oocytes complexes throughout the canine oestrous cycle

2020 ◽  
Vol 32 (11) ◽  
pp. 976
Author(s):  
Monica De los Reyes ◽  
Jaime Palomino ◽  
Carola Gallegos ◽  
Roberto Espinoza ◽  
Phillipe Dettleff ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Expression Patterns ◽  
Cumulus Cells ◽  
Oestrous Cycle ◽  
Mrna Levels ◽  
Chain Reaction ◽  
Antral Follicles ◽  
Gene And Protein Expression ◽  
Before And After ◽  
Polymerase Chain

The aim of this study was to evaluate the expression of connexin (Cx) 37 and Cx43 in canine cumulus–oocyte complexes (COCs) during the oestrous cycle. Cx localisation was analysed by immunohistochemistry and immunofluorescence, whereas protein and gene expression was evaluated by western blotting and quantitative polymerase chain reaction respectively; comparisons were made using analysis of variance. Both Cx37 and Cx43 were expressed in all follicular stages; Cx43 was identified in cumulus cells and Cx37 was identified in cumulus cells, zonae pellucida and oocytes. Immunofluorescence analyses showed that Cx37 remained unchanged during the preovulatory stage but decreased after ovulation, whereas Cx43 remained unchanged before and after ovulation. Cx43 transcripts increased (P&lt;0.05) during anoestrus and dioestrus in medium-sized follicles but remained unaltered during the pro-oestrus and antral stages during oestrus, before and after ovulation. Cx37 mRNA levels decreased in ovulated COCs (P&lt;0.05). The highest levels of Cx37 protein (P&lt;0.05) were detected in the preantral stage during anoestrus. In contrast, strong Cx43 signals were detected in oestrus and in medium-sized antral follicles in dioestrus (P&lt;0.05). Overall, we demonstrated that Cx37 and Cx43 exhibit different expression patterns, suggesting specific roles throughout growth. Maintenance of Cx expression before ovulation indicates the involvement of Cx37 and Cx43 in the prolonged meiotic arrest.

scholarly journals Comparison of expression patterns of six canonical clock genes of follicular phase and luteal phase in Small-tailed Han sheep

2021 ◽  
Vol 64 (2) ◽  
pp. 457-466
Author(s):  
Qi Han ◽  
Xiaoyun He ◽  
Ran Di ◽  
Mingxing Chu
Keyword(s):  
Gene Expression ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Clock Gene ◽  
Clock Genes ◽  
Expression Patterns ◽  
Mrna Levels ◽  
Clock Gene Expression ◽  
The Relationship ◽  
The Brain

Abstract. The circadian rhythm is a biological rhythm that is closely related to the rhythmic expression of a series of clock genes. Results from several studies have indicated that clock genes are associated with the estrous cycle in female animals. Until now, the relationship between estrus cycle transition and clock gene expression in reproductive-axis-related tissues has remained unknown in Small-tailed Han (STH) sheep. This study was conducted to analyze the expression patterns of six canonical clock genes (Clock, BMAL1, Per1, Per2, Cry1, and Cry2) in the follicle phase and luteal phase of STH sheep. We found that all six genes were expressed in the brain, cerebellum, hypothalamus, pituitary, ovary, uterus, and oviduct in follicle and luteal phases. The results indicated that Clock expression was significantly higher in the cerebellum, hypothalamus, and uterus of the luteal phase than that of the follicle phase, whereas BMAL1 expression was significantly higher in the hypothalamus of the luteal phase than that of the follicle phase. Per1 expression was significantly higher in the brain, cerebellum, hypothalamus, and pituitary of the luteal phase than that of the follicle phase, and Per2 expression was significantly higher in the hypothalamus, pituitary, and uterus of the luteal phase than that of the follicle phase. Cry1 expression was significantly higher in the brain, cerebellum, and hypothalamus of the luteal phase than that of the follicle phase, whereas Cry2 expression was significantly higher in the pituitary of the luteal phase than that of the follicle phase. The clock gene expression in all tissues was different between follicle and luteal phases, but all clock gene mRNA levels were found to exhibit higher expression among seven tissues in the luteal phase. Our results suggest that estrous cycles may be associated with clock gene expression in the STH sheep. This is the first study to systematically analyze the expression patterns of clock genes of different estrous cycle in ewes, which could form a basis for further studies to develop the relationship between clock genes and the estrous cycle.

Thymosins β-4 and β-10 are expressed in bovine ovarian follicles and upregulated in cumulus cells during meiotic maturation

2010 ◽  
Vol 22 (8) ◽  
pp. 1206 ◽  
Author(s):  
Mohamad Salhab ◽  
Pascal Papillier ◽  
Christine Perreau ◽  
Catherine Guyader-Joly ◽  
Joelle Dupont ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Expression Patterns ◽  
Cumulus Cells ◽  
Blastocyst Stage ◽  
Small Proteins ◽  
Progesterone Secretion ◽  
Inflammatory Processes ◽  
Polymerase Chain

β-Thymosins are small proteins that regulate the actin cytoskeleton and are involved in cell motility, differentiation, the induction of metalloproteinases, in anti-inflammatory processes and tumourigenesis. However, their roles in the ovary have not yet been elucidated. Using transcriptomics and real time reverse transcription–polymerase chain reaction validation, the present study demonstrates that thymosin β-4 (TMSB4) and thymosin β-10 (TMSB10) are upregulated in bovine cumulus cells (CCs) during in vitro maturation of cumulus–oocyte complexes (COCs) in parallel with an increase in mRNA expression of HAS2, COX2 and PGR genes. Using immunocytochemistry, both proteins were found to be localised mainly in granulosa cells, CCs and oocytes, in both the cytoplasm and nucleus, as well as being colocalised with F-actin stress fibres in CCs. Using different maturation mediums, we showed that the expression of TMSB10, but not TMSB4, was positively correlated with COC expansion and progesterone secretion and negatively correlated with apoptosis. Immunofluorescence, coupled with terminal deoxyribonucleotidyl transferase-mediated dUTP–digoxigenin nick end-labelling (TUNEL), demonstrated the absence of TMSB4 and/or TMSB10 in apoptotic cells. TMSB10 expression was higher in COCs matured in vivo than in vitro, and differences related to the age of the animal were observed. TMSB4 and/or TMSB10 expression was unchanged, whereas HAS2 overexpressed in CCs from oocytes that developed to the blastocyst stage in vitro compared with those that did not. Thus, TMSB4 and/or TMSB10 ovarian expression patterns suggest that these two thymosins may be involved in cumulus modifications during maturation.

Maturation Stage-Specific Regulation of Megakaryocytic Genes by Pointed-Domain Ets Proteins.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1737-1737
Author(s):  
Liyan Pang ◽  
Xun Wang ◽  
Yuhuan Wang ◽  
Gerd Blobel ◽  
Mortimer Poncz
Keyword(s):  
Gene Expression ◽  
Fetal Liver ◽  
Critical Role ◽  
Regulatory Region ◽  
Maturation Stage ◽  
Specific Gene ◽  
Mrna Levels ◽  
Specific Regulation

Abstract The pointed-domain Ets transcription factor Fli-1 has a critical role during megakaryocyte-specific gene expression. Previously, we demonstrated that Fli-1 occupies the early megakaryocyte-specific gene αIIb in vivo. Moreover, our work suggested a mechanism for Fli-1 function by showing that Fli-1 facilitates GATA-1/FOG-1 dependent expression of the αIIb gene. However, studies by others with a targeted disruption of the Fli-1 gene in mice showed that while Fli-1 is essential for normal megakaryocyte maturation, αIIb mRNA levels were not significantly reduced in the resulting megakaryocytes, suggesting that a related Ets factor(s) might compensate for the loss of Fli-1. Here we show that the widely expressed pointed domain Ets protein GABPα specifically binds in vitro to Ets elements from two early megakaryocyte-specific genes, αIIb and c-mpl. Chromatin immunoprecipitation (ChIP) experiments using primary murine fetal liver-derived megakaryocytes reveal that GABPα associates with αIIb and c-mpl in vivo. Moreover, GABPα is capable of mediating GATA-1/FOG-1 synergy in the context of αIIb promoter constructs. These results suggest that GABPα contributes to megakaryocyte-restricted gene expression and is capable of at least partially compensating for the loss of Fli-1. However, loss of Fli-1 leads to a pronounced decrease in the expression of the late megakaryocyte-specific gene GPIX, indicating that compensation by GABPα is incomplete. Consistent with this observation, ChIP experiments fail to detect significant levels of GABPα at the regulatory region of GPIX while Fli-1 is readily detected there. Together, these results point to a model in which Fli-1 and GABPα serve overlapping, but distinct roles, during the development of megakaryocytes. GABPα may be important during early megakaryopoiesis, but Fli-1 exerting an essential role during late stages of maturation.

scholarly journals FGF2/FGFR signaling promotes cumulus-oocyte complex maturation in vitro

Reproduction ◽  
2020 ◽  
Author(s):  
Chao Du ◽  
John S Davis ◽  
Chao Chen ◽  
Zan Li ◽  
Ye Cao ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Mapk Pathway ◽  
Expression Patterns ◽  
Cumulus Cells ◽  
Cumulus Expansion ◽  
Meiotic Progression ◽  
Oocyte Meiosis ◽  
Maturation In Vitro ◽  
Fgfr Signaling

Fibroblast growth factor 2 (FGF2), a member of FGF family, binds with FGF receptors (FGFR) to initiate biological functions in various somatic cells. However, little is known regarding the role of FGF2/FGFR on oocyte meiosis. In this study, we investigated expression patterns and functions of FGF2/FGFR during in vitro maturation (IVM) of mouse cumulus-oocyte complexes (COCs). Among four FGFRs, Ffgr1 was the most abundant in COCs. The transcripts for Fgf2 and Ffgr1 in COCs increased during IVM. Ffgr1 was present in oocytes and cumulus cells, while Fgf2 was present in only cumulus cells. Treatment of COCs with the selective FGFR inhibitor SU5402 blocked oocyte meiotic progression and downregulated expression of Bmp15 and Gdf9. In contrast, supplement of FGF2 promoted oocyte meiotic progression and upregulated Bmp15 and Gdf9 expression. Inhibition of FGFR with SU5402 reduced cumulus expansion and expressions of Ptx3, Has2 and Tnfaip6. Treatment with FGF2 increased Ptx3 and Has2 expression. Inhibition of FGFR had no effect on meiotic progression of denuded oocytes (DOs). However, co-culture of DOs with COCs or supplementation with FGF2 promoted meiotic progression of DOs. Inhibition of FGF2/FGFR signaling also downregulated Ffgr1 expression, while supplemental FGF2 upregulated Fgfr1 expression. Furthermore, inhibition of FGFR in COCs interrupted the c-Mos/MAPK pathway and maturation-promoting factor (MPF), as indicated by downregulation of oocyte c-mos and Ccnb1 transcripts, respectively. Overall, this study suggests that FGF2 produced by cumulus cells, activates a FGF2/FGFR autocrine/paracrine loop within COCs to regulate cumulus expansion and oocyte meiosis. These findings reveal a novel role for FGF2/FGFR signaling during in vitro maturation of COCs.

80 GLOBAL GENE EXPRESSION PATTERNS OF FRESH AND VITRIFIED IN VITRO-PRODUCED BOVINE BLASTOCYSTS

2013 ◽  
Vol 25 (1) ◽  
pp. 187
Author(s):  
M. J. Sudano ◽  
E. S. Caixeta ◽  
D. M. Paschoal ◽  
T. S. Rascado ◽  
L. F. Crocomo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Expression Patterns ◽  
Rna Extraction ◽  
Global Gene Expression ◽  
Differentially Expressed ◽  
Microarray Data Analysis ◽  
Gene Expression Patterns ◽  
Mrna Levels

Over the past decades, there have been great advances in in vitro production (IVP) systems with improved culture methods and new knowledge regarding embryo genetics, physiology, ultrastructure, and morphology. Nevertheless, a major obstacle for dissemination of this technology is the great sensitivity of IVP embryos to cryopreservation. The objective was to study the global gene-expression patterns of fresh and vitrified IVP bovine embryos. Oocytes (N = 1290) were matured and fertilized in vitro (Day 0). Presumptive zygotes were cultured in SOFaa with 0.5% BSA and 2.5% of FCS. Cleavage and blastocyst production was evaluated after 3 and 7 days under standard culture conditions (at 38.5°C in atmosphere of 5% O2, 5% CO2, and 90% N2). On Day 7, half of the blastocysts were vitrified (n = 94), warmed (Sudano et al. 2011 Theriogenology 75, 1211–1220), and returned for 24 h of additional culture (re-expansion and hatching; hatched was evaluated 12 and 24 h after warming, respectively) when their RNA was extracted (vitrified group). The remaining embryos returned to culture until Day 8 when their RNA was extracted (fresh group). Total RNA extraction of a single blastocyst was performed using the PicoPure Kit (Applied Biosystems®, Foster City, CA, USA). The RNA samples were DNAse treated (Qiagen®, Valencia, CA, USA), and mRNA was amplified (RiboAmp Kit®). The aRNA output was evaluated with a NanoDrop (Thermo®, Wilmington, DE, USA) and Bioanalyzer (Agilent®, Santa Clara, CA, USA). Biotin-labelled and fragmented cRNA were obtained with the 3′IVT Kit (Affymetrix®, Santa Clara, CA, USA) to perform hybridization (N = 6–7, respectively, for vitrified and fresh groups) using the GeneChip Bovine Array (Affymetrix®). Microarray data analysis was performed with the FlexArray 1.6.1.1. Genes with a fold change of at least 2 and a probability of P ≤ 0.05 were considered differentially expressed. Real-time PCR was used to validate microarray results (N = 11–15, respectively, for vitrified and fresh groups). As a control, a pool of 200 blastocysts was submitted or not to mRNA amplification followed by the reverse transcription and qPCR of 17 genes. For statistical analyses, PROC GLIMMIX, PROC LOGISTIC, and PROC CORR were used. Cleavage and blastocyst production rates were 86.8 ± 1.0 and 32.5 ± 1.9%, respectively. Re-expansion and hatching/hatched rates were 69.3 and 19.3%, respectively. Messenger RNA abundance of amplified and nonamplified RNA had a high correlation (r = 0.89, P < 0.01). The microarray analysis indicated 383 differentially expressed genes (P ≤ 0.05) between fresh and vitrified blastocysts. Genes involved in apoptosis (PRDX2), heat shock (HSPA5), maternal recognition of pregnancy (IFNT2 and PAG2), and cell differentiation and placenta formation (KRT18) were downregulated in vitrified embryos. According to qPCR analysis, mRNA abundance of IFNT2, PRDX2, and KRT18 was downregulated, whereas HSPA5 mRNA levels were upregulated in vitrified blastocysts. Messenger RNA abundance of PAG2 was not different (P = 0.46) between fresh and vitrified embryos. In conclusion, vitrification alters the expression profile of the genes IFNT2, PRDX2, KRT18, and HSPA5 that can be related with embryo postcryopreservation survival capacity. FAPESP and LNBio-CNPEM are acknowledged.

Expression of apoptotic genes in immature and in vitro matured equine oocytes and cumulus cells

Zygote ◽  
2011 ◽  
Vol 21 (3) ◽  
pp. 279-285 ◽  
Author(s):  
P.M.M. Leon ◽  
V.F. Campos ◽  
C. Kaefer ◽  
K.R. Begnini ◽  
A.J.A. McBride ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cumulus Cells ◽  
Chain Reaction ◽  
Viable Cells ◽  
Significant Difference ◽  
Polymerase Chain ◽  
Apoptotic Genes ◽  
Quantify Gene Expression ◽  
Lower Expression

SummaryThe gene expression of Bax, Bcl-2, survivin and p53, following in vitro maturation of equine oocytes, was compared in morphologically distinct oocytes and cumulus cells. Cumulus–oocyte complexes (COC) were harvested and divided into two groups: G1 – morphologically healthy cells; and G2 – less viable cells or cells with some degree of atresia. Total RNA was isolated from both immature and in vitro matured COC and real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to quantify gene expression. Our results showed there was significantly higher expression of survivin (P < 0.05) and lower expression of p53 (P < 0.01) in oocytes compared with cumulus cells in G1. No significant difference in gene expression was observed following in vitro maturation or in COC derived from G1 and G2. However, expression of the Bax gene was significantly higher in cumulus cells from G1 (P < 0.02).

scholarly journals Differential Gonadotropin-Releasing Hormone (GnRH) and GnRH Receptor Messenger Ribonucleic Acid Expression Patterns in Different Tissues of the Female Rat across the Estrous Cycle

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3401-3408 ◽  
Author(s):  
Tamar D. Schirman-Hildesheim ◽  
Tzachi Bar ◽  
Nurit Ben-Aroya ◽  
Yitzhak Koch
Keyword(s):  
Estrous Cycle ◽  
Similar Pattern ◽  
Expression Patterns ◽  
Physiological Role ◽  
Gnrh Receptor ◽  
Mrna Levels ◽  
Female Rat ◽  
Messenger Ribonucleic Acid ◽  
Early Afternoon ◽  
Specific Regulation

Abstract GnRH, the main regulator of reproduction, is produced in a variety of tissues outside of the hypothalamus, its main site of synthesis and release. We aimed to determine whether GnRH produced in the female rat pituitary and ovaries is involved in the processes leading to ovulation. We studied the expression patterns of GnRH and GnRH receptor (GnRH-R) in the same animals throughout the estrous cycle using real-time PCR. Hypothalamic levels of GnRH mRNA were highest at 1700 h on proestrus, preceding the preovulatory LH surge. No significant changes in the level of hypothalamic GnRH-R mRNA were detected, although fluctuations during the day of proestrus are evident. High pituitary GnRH mRNA was detected during the day of estrus, in the morning of diestrus 1, and at noon on proestrus. Pituitary GnRH-R displayed a similar pattern of expression, except on estrus, when its mRNA levels declined. Ovarian GnRH mRNA levels increased in the morning of diestrus 1 and early afternoon of proestrus. Here, too, GnRH-R displayed a somewhat similar pattern of expression to that of its ligand. To the best of our knowledge, this is the first demonstration of a GnRH expression pattern in the pituitary and ovary of any species. The different timings of the GnRH peaks in the three tissues imply differential tissue-specific regulation. We believe that the GnRH produced in the anterior pituitary and ovary could play a physiological role in the preparation of these organs for the midcycle gonadotropin surge and ovulation, respectively, possibly via local GnRH-gonadotropin axes.

scholarly journals HNF1alpha is involved in tissue-specific regulation of CFTR gene expression

2004 ◽  
Vol 378 (3) ◽  
pp. 909-918 ◽  
Author(s):  
Nathalie MOUCHEL ◽  
Sytse A. HENSTRA ◽  
Victoria A. McCARTHY ◽  
Sarah H. WILLIAMS ◽  
Marios PHYLACTIDES ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Tissue Specificity ◽  
Regulatory Elements ◽  
Upstream Region ◽  
Mrna Levels ◽  
Tissue Specific ◽  
Specific Regulation

The CFTR (cystic fibrosis transmembrane conductance regulator) gene shows a complex pattern of expression with tissue-specific and temporal regulation. However, the genetic elements and transcription factors that control CFTR expression are largely unidentified. The CFTR promoter does not confer tissue specificity on gene expression, suggesting that there are regulatory elements outside the upstream region. Analysis of potential regulatory elements defined as DNase 1-hypersensitive sites within introns of the gene revealed multiple predicted binding sites for the HNF1α (hepatocyte nuclear factor 1α) transcription factor. HNF1α, which is expressed in many of the same epithelial cell types as CFTR and shows similar differentiation-dependent changes in gene expression, bound to these sites in vitro. Overexpression of heterologous HNF1α augmented CFTR transcription in vivo. In contrast, antisense inhibition of HNF1α transcription decreased the CFTR mRNA levels. Hnf1α knockout mice showed lower levels of CFTR mRNA in their small intestine in comparison with wild-type mice. This is the first report of a transcription factor, which confers tissue specificity on the expression of this important disease-associated gene.

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