1
|
Zhang J, Xu Y, Wang C, Tuo X, Zhao X, Qiao W, Tan J. PREB inhibits the replication of prototype foamy virus by affecting its transcription. Virol J 2023; 20:244. [PMID: 37885034 PMCID: PMC10604407 DOI: 10.1186/s12985-023-02211-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 10/13/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND Foamy viruses (FVs) are unique nonpathogenic retroviruses, which remain latent in the host for a long time. Therefore, they may be safe, effective gene transfer vectors. In this study, were assessed FV-host cell interactions and the molecular mechanisms underlying FV latent infection. METHODS We used the prototype FV (PFV) to infect HT1080 cells and a PFV indicator cell line (PFVL) to measure virus titers. After 48 h of infection, the culture supernatant (i.e., cell-free PFV particles) and transfected cells (i.e., cell-associated PFV particles) were harvested and incubated with PFVL. After another 48 h, the luciferase activity was used to measure virus titers. RESULTS Through transcriptomics sequencing, we found that PREB mRNA expression was significantly upregulated. Moreover, PREB overexpression reduced PFV replication, whereas endogenous PREB knockdown increased PFV replication. PREB interacted with the Tas DNA-binding and transcriptional activation domains and interfered with its binding to the PFV long terminal repeat and internal promoter, preventing the recruitment of transcription factors and thereby inhibiting the transactivation function of Tas. PREB C-terminal 329-418 aa played a major role in inhibiting PFV replication; PREB also inhibited bovine FV replication. Therefore, PREB has a broad-spectrum inhibitory effect on FV replication. CONCLUSIONS Our results demonstrated that PREB inhibits PFV replication by impeding its transcription.
Collapse
Affiliation(s)
- Junshi Zhang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300071, China
- Department of Hematology, Oncology Centrer, Tianjin Union Medical Center, No.190 Jieyuan Road, Hongqiao District, Tianjin, 300121, P. R. China
| | - Yali Xu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Chenchen Wang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Xiaopeng Tuo
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Xingli Zhao
- Department of Hematology, Oncology Centrer, Tianjin Union Medical Center, No.190 Jieyuan Road, Hongqiao District, Tianjin, 300121, P. R. China
| | - Wentao Qiao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Juan Tan
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300071, China.
| |
Collapse
|
2
|
Vélez EJ, Nasri A, Unniappan S. Nesfatin-1 and Nesfatin-1-like peptide suppress basal and TRH-Induced expression of prolactin and prolactin regulatory element-binding protein mRNAs in rat GH3 somatolactotrophs. Mol Cell Endocrinol 2021; 529:111269. [PMID: 33819522 DOI: 10.1016/j.mce.2021.111269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/20/2021] [Accepted: 03/29/2021] [Indexed: 11/23/2022]
Abstract
Prolactin (PRL), mainly synthesized and secreted by the lactotrophs and somatolactotrophs of the anterior pituitary, is a pleiotropic hormone that regulates lactation. In the last decade, nesfatin-1 (NESF) and NESF-like peptide (NLP), encoded in nucleobindin 1 and 2 (NUCB1 and NUCB2), respectively, were characterized as metabolic factors with a potential role in the control of pituitary hormones. We hypothesized that NUCBs and their encoded peptides (NESF and NLP) suppress PRL transcription in the pituitary. The main objective of this research was to determine whether exogenous NESF and NLP, and/or endogenous NUCB1 and NUCB2 regulate the expression of prl and preb mRNAs. Using immortalized rat somatolactotrophs (GH3 cells), dose-response studies were performed to test whether NESF and NLP affect prl and preb. Moreover, the ability of these peptides to modulate the effects of the PRL stimulator thyrotropin releasing hormone (TRH) was studied. Besides, the effects of siRNA-mediated knockdown of endogenous NUCBs on prl and preb mRNAs were determined. NESF and NLP reduced the transcription of prl and preb in GH3 cells. Both NESF and NLP also prevented the stimulatory effects of TRH prl and preb expression. The knockdown of endogenous NUCB1 attenuates both basal prl and TRH-induced expression of prl and preb, while the silencing of NUCBs did not affect the actions of exogenous NESF or NLP. Overall, this work reveals that NUCBs and encoded-peptides are novel regulators of PRL. Future research should test whether the effects observed here in GH3 cells are preserved both in vivo and at the post-transcriptional level.
Collapse
Affiliation(s)
- Emilio J Vélez
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Atefeh Nasri
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
| |
Collapse
|
3
|
Blagotinšek Cokan K, Mavri M, Rutland CS, Glišić S, Senćanski M, Vrecl M, Kubale V. Critical Impact of Different Conserved Endoplasmic Retention Motifs and Dopamine Receptor Interacting Proteins (DRIPs) on Intracellular Localization and Trafficking of the D 2 Dopamine Receptor (D 2-R) Isoforms. Biomolecules 2020; 10:biom10101355. [PMID: 32977535 PMCID: PMC7598153 DOI: 10.3390/biom10101355] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/09/2020] [Accepted: 09/18/2020] [Indexed: 01/13/2023] Open
Abstract
The type 2 dopamine receptor D2 (D2-R), member of the G protein-coupled receptor (GPCR) superfamily, exists in two isoforms, short (D2S-R) and long (D2L-R). They differ by an additional 29 amino acids (AA) in the third cytoplasmic loop (ICL3) of the D2L-R. These isoforms differ in their intracellular localization and trafficking functionality, as D2L-R possesses a larger intracellular pool, mostly in the endoplasmic reticulum (ER). This review focuses on the evolutionarily conserved motifs in the ICL3 of the D2-R and proteins interacting with the ICL3 of both isoforms, specifically with the 29 AA insert. These motifs might be involved in D2-R exit from the ER and have an impact on cell-surface and intracellular localization and, therefore, also play a role in the function of dopamine receptor signaling, ligand binding and possible homo/heterodimerization. Our recent bioinformatic data on potential new interaction partners for the ICL3 of D2-Rs are also presented. Both are highly relevant, and have clinical impacts on the pathophysiology of several diseases such as Parkinson’s disease, schizophrenia, Tourette’s syndrome, Huntington’s disease, manic depression, and others, as they are connected to a variety of essential motifs and differences in communication with interaction partners.
Collapse
Affiliation(s)
- Kaja Blagotinšek Cokan
- Department of Anatomy, Histology with Embryology and Cytology, Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia; (K.B.C.); (M.M.); (M.V.)
| | - Maša Mavri
- Department of Anatomy, Histology with Embryology and Cytology, Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia; (K.B.C.); (M.M.); (M.V.)
| | - Catrin Sian Rutland
- School of Veterinary Medicine and Science, Medical Faculty, University of Nottingham, Sutton, Bonington Campus, Loughborough LE12 5RD, UK;
| | - Sanja Glišić
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Mike Petrovića Alasa 12-14, 11351 Vinča, Belgrade, Serbia; (S.G.); (M.S.)
| | - Milan Senćanski
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Mike Petrovića Alasa 12-14, 11351 Vinča, Belgrade, Serbia; (S.G.); (M.S.)
| | - Milka Vrecl
- Department of Anatomy, Histology with Embryology and Cytology, Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia; (K.B.C.); (M.M.); (M.V.)
| | - Valentina Kubale
- Department of Anatomy, Histology with Embryology and Cytology, Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia; (K.B.C.); (M.M.); (M.V.)
- Correspondence:
| |
Collapse
|
4
|
Wang D, Huang J, Gui T, Yang Y, Feng T, Tzvetkov NT, Xu T, Gai Z, Zhou Y, Zhang J, Atanasov AG. SR-BI as a target of natural products and its significance in cancer. Semin Cancer Biol 2020; 80:18-38. [PMID: 31935456 DOI: 10.1016/j.semcancer.2019.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/25/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023]
Abstract
Scavenger receptor class B type I (SR-BI) protein is an integral membrane glycoprotein. SR-BI is emerging as a multifunctional protein, which regulates autophagy, efferocytosis, cell survival and inflammation. It is well known that SR-BI plays a critical role in lipoprotein metabolism by mediating cholesteryl esters selective uptake and the bi-directional flux of free cholesterol. Recently, SR-BI has also been identified as a potential marker for cancer diagnosis, prognosis, or even a treatment target. Natural products are a promising source for the discovery of new drug leads. Multiple natural products were identified to regulate SR-BI protein expression. There are still a number of challenges in modulating SR-BI expression in cancer and in using natural products for modulation of such protein expression. In this review, our purpose is to discuss the relationship between SR-BI protein and cancer, and the molecular mechanisms regulating SR-BI expression, as well as to provide an overview of natural products that regulate SR-BI expression.
Collapse
Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Jiansheng Huang
- Department of Medicine, Vanderbilt University Medical Center, 318 Preston Research Building, 2200 Pierce Avenue, Nashville, Tennessee, 37232, USA
| | - Ting Gui
- Key Laboratory of Traditional Chinese Medicine for Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Yaxin Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Tingting Feng
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China
| | - Nikolay T Tzvetkov
- Department of Biochemical Pharmacology and Drug Design, Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, 21 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria
| | - Tao Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Zhibo Gai
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Ying Zhou
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China.
| | - Jingjie Zhang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China.
| | - Atanas G Atanasov
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, 05-552, Jastrzębiec, Poland; Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria; Institute of Neurobiology, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria; Ludwig Boltzmann Institute for Digital Health and Patient Safety, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
| |
Collapse
|
5
|
Neuroendocrine aging precedes perimenopause and is regulated by DNA methylation. Neurobiol Aging 2018; 74:213-224. [PMID: 30497015 DOI: 10.1016/j.neurobiolaging.2018.09.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 09/21/2018] [Accepted: 09/21/2018] [Indexed: 11/22/2022]
Abstract
Perimenopause marks initiation of female reproductive senescence. Age of onset is only 47% heritable suggesting that additional factors other than inheritance regulate this endocrine aging transition. To elucidate these factors, we characterized transcriptional and epigenomic changes across endocrine aging using a rat model that recapitulates characteristics of the human perimenopause. RNA-seq analysis revealed that hypothalamic aging precedes onset of perimenopause. In the hypothalamus, global DNA methylation declined with both age and reproductive senescence. Genome-wide epigentic analysis revealed changes in DNA methylation in genes required for hormone signaling, glutamate signaling, and melatonin and circadian pathways. Specific epignetic changes in these signaling pathways provide insight into the origin of perimenopause-associated neurological symptoms such as insomnia. Treatment with 5-aza-2'-deoxycytidine, a DNA-methyltransferase-1 inhibitor, accelerated transition to reproductive senescence/ whereas supplementation with methionine, a S-adenosylmethionine precursor, delayed onset of perimenopause and endocrine aging. Collectively, these data provide evidence for a critical period of female neuroendocrine aging in brain that precedes ovarian failure and that DNA methylation regulates the transition duration of perimenopause to menopause.
Collapse
|
6
|
Musumeci G, Castorina S, Castrogiovanni P, Loreto C, Leonardi R, Aiello FC, Magro G, Imbesi R. A journey through the pituitary gland: Development, structure and function, with emphasis on embryo-foetal and later development. Acta Histochem 2015; 117:355-66. [PMID: 25858531 DOI: 10.1016/j.acthis.2015.02.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 12/28/2014] [Accepted: 02/05/2015] [Indexed: 12/22/2022]
Abstract
The pituitary gland and the hypothalamus are morphologically and functionally associated in the endocrine and neuroendocrine control of other endocrine glands. They therefore play a key role in a number of regulatory feedback processes that co-ordinate the whole endocrine system. Here we review the neuroendocrine system, from the discoveries that led to its identification to some recently clarified embryological, functional, and morphological aspects. In particular we review the pituitary gland and the main notions related to its development, organization, cell differentiation, and vascularization. Given the crucial importance of the factors controlling neuroendocrine system development to understand parvocellular neuron function and the aetiology of the congenital disorders related to hypothalamic-pituitary axis dysfunction, we also provide an overview of the molecular and genetic studies that have advanced our knowledge in the field. Through the action of the hypothalamus, the pituitary gland is involved in the control of a broad range of key aspects of our lives: the review focuses on the hypothalamic-pituitary-gonadal axis, particularly GnRH, whose abnormal secretion is associated with clinical conditions involving delayed or absent puberty and reproductive dysfunction.
Collapse
|
7
|
Featherstone K, White MRH, Davis JRE. The prolactin gene: a paradigm of tissue-specific gene regulation with complex temporal transcription dynamics. J Neuroendocrinol 2012; 24:977-90. [PMID: 22420298 PMCID: PMC3505372 DOI: 10.1111/j.1365-2826.2012.02310.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Transcription of numerous mammalian genes is highly pulsatile, with bursts of expression occurring with variable duration and frequency. The presence of this stochastic or 'noisy' expression pattern has been relatively unexplored in tissue systems. The prolactin gene provides a model of tissue-specific gene regulation resulting in pulsatile transcription dynamics in both cell lines and endocrine tissues. In most cell culture models, prolactin transcription appears to be highly variable between cells, with differences in transcription pulse duration and frequency. This apparently stochastic transcription is constrained by a transcriptional refractory period, which may be related to cycles of chromatin remodelling. We propose that prolactin transcription dynamics result from the summation of oscillatory cellular inputs and by regulation through chromatin remodelling cycles. Observations of transcription dynamics in cells within pituitary tissue show reduced transcriptional heterogeneity and can be grouped into a small number of distinct patterns. Thus, it appears that the tissue environment is able to reduce transcriptional noise to enable coordinated tissue responses to environmental change. We review the current knowledge on the complex tissue-specific regulation of the prolactin gene in pituitary and extra-pituitary sites, highlighting differences between humans and rodent experimental animal models. Within this context, we describe the transcription dynamics of prolactin gene expression and how this may relate to specific processes occurring within the cell.
Collapse
Affiliation(s)
- K Featherstone
- Developmental Biomedicine Research Group, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK.
| | | | | |
Collapse
|
8
|
Perez-Castro C, Renner U, Haedo MR, Stalla GK, Arzt E. Cellular and molecular specificity of pituitary gland physiology. Physiol Rev 2012; 92:1-38. [PMID: 22298650 DOI: 10.1152/physrev.00003.2011] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The anterior pituitary gland has the ability to respond to complex signals derived from central and peripheral systems. Perception of these signals and their integration are mediated by cell interactions and cross-talk of multiple signaling transduction pathways and transcriptional regulatory networks that cooperate for hormone secretion, cell plasticity, and ultimately specific pituitary responses that are essential for an appropriate physiological response. We discuss the physiopathological and molecular mechanisms related to this integrative regulatory system of the anterior pituitary gland and how it contributes to modulate the gland functions and impacts on body homeostasis.
Collapse
Affiliation(s)
- Carolina Perez-Castro
- Laboratorio de Regulación de la Expresión Génica en el Crecimiento, Supervivencia y Diferenciación Celular,Departamento de Química Biológica, Universidad de Buenos Aires, Argentina
| | | | | | | | | |
Collapse
|
9
|
Nassiri F, Cusimano MD, Scheithauer BW, Rotondo F, Fazio A, Syro LV, Kovacs K, Lloyd RV. Prolactinomas: diagnosis and treatment. Expert Rev Endocrinol Metab 2012; 7:233-241. [PMID: 30764014 DOI: 10.1586/eem.12.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pituitary lactotrophs secrete prolactin. This process is enhanced by estrogen and inhibited by dopamine. Prolactinomas are benign neoplasms that rarely increase in size and are classified according to size as microadenomas (<10 mm diameter) or macroadenomas (>10 mm diameter). The clinical features of prolactinomas most commonly result from prolactin's effect on the gonads and breast in women and from mass effect in men. This review details the clinical features and management of patients with prolactinomas.
Collapse
Affiliation(s)
- Farshad Nassiri
- a Department of Surgery, Division of Neurosurgery, St Michael's Hospital, University of Toronto, ON, Canada
| | - Michael D Cusimano
- a Department of Surgery, Division of Neurosurgery, St Michael's Hospital, University of Toronto, ON, Canada
| | - Bernd W Scheithauer
- b Department of Laboratory Medicine & Pathology, Mayo Clinic, Rochester, MN, USA
| | - Fabio Rotondo
- c Department of Laboratory Medicine, Division of Pathology, 30 Bond Street, St Michael's Hospital, Toronto, ON, M5B 1W8, Canada
- f Department of Laboratory Medicine, Division of Pathology, 30 Bond Street, St Michael's Hospital, Toronto, ON, M5B 1W8, Canada.
| | - Alessandra Fazio
- a Department of Surgery, Division of Neurosurgery, St Michael's Hospital, University of Toronto, ON, Canada
| | - Luis V Syro
- d Department of Neurosurgery, Clinica Medellin & Hospital Pablo Tobon Uribe, Medellin, Colombia
| | - Kalman Kovacs
- c Department of Laboratory Medicine, Division of Pathology, 30 Bond Street, St Michael's Hospital, Toronto, ON, M5B 1W8, Canada
| | - Ricardo V Lloyd
- e Department of Pathology & Laboratory Medicine, University of Wisconsin Hospital & Clinics, Madison, WI, USA
| |
Collapse
|
10
|
Mijiddorj T, Kanasaki H, Purwana I, Unurjargal S, Oride A, Miyazaki K. Effects of estradiol and progesterone on prolactin transcriptional activity in somatolactotrophic cells. Endocr J 2012; 59:867-79. [PMID: 22785235 DOI: 10.1507/endocrj.ej12-0093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We examined the effects of sex steroids on prolactin promoter activity in rat somatolactotrophic GH3 cells. Both estradiol (E2) and progesterone (P4) were found to inhibit basal prolactin promoter activity, but to potentiate Thyrotropin-releasing hormone (TRH)-induced prolactin promoter activity. P4 had a greater inhibitory effect on basal prolactin promoter activity than E2, and P4 also potentiated TRH-induced prolactin promoter more potently than E2. Combined treatment with E2 and P4 further increased TRH-induced prolactin promoter activity. E2 and P4 also both reduced basal serum response element (SRE) promoter activity, and increased TRH-induced SRE promoter activity. Combination treatment with E2 and P4 reduced basal activity of SRE promoter and increased TRH-induced SRE activity more potently than E2 or P4 alone. In contrast, basal cAMP response element (CRE) promoter activity was not influenced by either E2 or P4, although TRH-induced CRE promoter was potentiated by each of these steroids, and was further increased by E2 and P4 combination treatment. Both E2 and P4 increased TRH-induced extracellular signal-regulated kinase (ERK) phosphorylation; however, intracellular cAMP levels was not influenced by E2 or P4. TRH-induced CRE promoter was inhibited by mitogen-activated protein kinase/ERK kinase (MEK) inhibitor and was increased by overexpression of MEK kinase (MEKK). This study showed that ERK and SRE transcriptional pathways, but not the cAMP/CRE pathway, may be involved in the suppression of basal prolactin promoter activity, whereas both the ERK/SRE and MAP kinase-mediated CRE pathways appear to be involved in the increased transcriptional efficiency of the prolactin promoter induced by TRH stimulation.
Collapse
Affiliation(s)
- Tselmeg Mijiddorj
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| | | | | | | | | | | |
Collapse
|