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Wu CYC, Zhang Y, Xu L, Huang Z, Zou P, Clemons GA, Li C, Citadin CT, Zhang Q, Lee RHC. The role of serum/glucocorticoid-regulated kinase 1 in brain function following cerebral ischemia. J Cereb Blood Flow Metab 2024; 44:1145-1162. [PMID: 38235747 PMCID: PMC11179613 DOI: 10.1177/0271678x231224508] [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: 08/15/2023] [Revised: 11/30/2023] [Accepted: 12/05/2023] [Indexed: 01/19/2024]
Abstract
Cardiopulmonary arrest (CA) is a major cause of death/disability in the U.S. with poor prognosis and survival rates. Current therapeutic challenges are physiologically complex because they involve hypoperfusion (decreased cerebral blood flow), neuroinflammation, and mitochondrial dysfunction. We previously discovered novel serum/glucocorticoid-regulated kinase 1 (SGK1) is highly expressed in brain of neurons that are susceptible to ischemia (hippocampus and cortex). We inhibited SGK1 and utilized pharmacological (specific inhibitor, GSK650394) and neuron-specific genetic approaches (shRNA) in rodent models of CA to determine if SGK1 is responsible for hypoperfusion, neuroinflammation, mitochondrial dysfunctional, and neurological deficits after CA. Inhibition of SGK1 alleviated cortical hypoperfusion and neuroinflammation (via Iba1, GFAP, and cytokine array). Treatment with GSK650394 enhanced mitochondrial function (via Seahorse respirometry) in the hippocampus 3 and 7 days after CA. Neuronal injury (via MAP2, dMBP, and Golgi staining) in the hippocampus and cortex was observed 7 days after CA but ameliorated with SGK1-shRNA. Moreover, SGK1 mediated neuronal injury by regulating the Ndrg1-SOX10 axis. Finally, animals subjected to CA exhibited learning/memory, motor, and anxiety deficits after CA, whereas SGK1 inhibition via SGK1-shRNA improved neurocognitive function. The present study suggests the fundamental roles of SGK1 in brain circulation and neuronal survival/death in cerebral ischemia-related diseases.
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Affiliation(s)
- Celeste Yin-Chieh Wu
- Stroke Center for Research, Louisiana State University Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health, Shreveport, LA, USA
| | - Yulan Zhang
- Stroke Center for Research, Louisiana State University Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health, Shreveport, LA, USA
| | - Li Xu
- Stroke Center for Research, Louisiana State University Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health, Shreveport, LA, USA
| | - Zhihai Huang
- Stroke Center for Research, Louisiana State University Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health, Shreveport, LA, USA
| | - Peibin Zou
- Stroke Center for Research, Louisiana State University Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health, Shreveport, LA, USA
| | - Garrett A Clemons
- Department of Cellular Biology and Anatomy, Louisiana State University Health, Shreveport, LA, USA
| | - Chun Li
- Stroke Center for Research, Louisiana State University Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health, Shreveport, LA, USA
| | - Cristiane T Citadin
- Department of Cellular Biology and Anatomy, Louisiana State University Health, Shreveport, LA, USA
| | - Quanguang Zhang
- Stroke Center for Research, Louisiana State University Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health, Shreveport, LA, USA
| | - Reggie Hui-Chao Lee
- Stroke Center for Research, Louisiana State University Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health, Shreveport, LA, USA
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Zhang Q, Tian Y, Fu Z, Wu S, Lan H, Zhou X, Shen W, Lou Y. The role of serum-glucocorticoid regulated kinase 1 in reproductive viability: implications from prenatal programming and senescence. Mol Biol Rep 2024; 51:376. [PMID: 38427115 PMCID: PMC10907440 DOI: 10.1007/s11033-024-09341-8] [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: 11/21/2023] [Accepted: 02/09/2024] [Indexed: 03/02/2024]
Abstract
OBJECTIVE Organisms and cellular viability are of paramount importance to living creatures. Disruption of the balance between cell survival and apoptosis results in compromised viability and even carcinogenesis. One molecule involved in keeping this homeostasis is serum-glucocorticoid regulated kinase (SGK) 1. Emerging evidence points to a significant role of SGK1 in cell growth and survival, cell metabolism, reproduction, and life span, particularly in prenatal programming and reproductive senescence by the same token. Whether the hormone inducible SGK1 kinase is a major driver in the pathophysiological processes of prenatal programming and reproductive senescence? METHOD The PubMed/Medline, Web of Science, Embase/Ovid, and Elsevier Science Direct literature databases were searched for articles in English focusing on SGK1 published up to July 2023 RESULT: Emerging evidence is accumulating pointing to a pathophysiological role of the ubiquitously expressed SGK1 in the cellular and organismal viability. Under the regulation of specific hormones, extracellular stimuli, and various signals, SGK1 is involved in several biological processes relevant to viability, including cell proliferation and survival, cell migration and differentiation. In line, SGK1 contributes to the development of germ cells, embryos, and fetuses, whereas SGK1 inhibition leads to abnormal gametogenesis, embryo loss, and truncated reproductive lifespan. CONCLUTION SGK1 integrates a broad spectrum of effects to maintain the homeostasis of cell survival and apoptosis, conferring viability to multiple cell types as well as both simple and complex organisms, and thus ensuring appropriate prenatal development and reproductive lifespan.
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Affiliation(s)
- Qiying Zhang
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, No. 453 Tiyuchang Road, Hangzhou, 310007, Zhejiang, China
| | - Ye Tian
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, No. 453 Tiyuchang Road, Hangzhou, 310007, Zhejiang, China
| | - Zhujing Fu
- Jinhua Municipal Central Hospital, Jinhua, 321001, China
| | - Shuangyu Wu
- Medical School, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Huizhen Lan
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, No. 453 Tiyuchang Road, Hangzhou, 310007, Zhejiang, China
| | - Xuanle Zhou
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, No. 453 Tiyuchang Road, Hangzhou, 310007, Zhejiang, China
| | - Wendi Shen
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, No. 453 Tiyuchang Road, Hangzhou, 310007, Zhejiang, China
| | - Yiyun Lou
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, No. 453 Tiyuchang Road, Hangzhou, 310007, Zhejiang, China.
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Hayes E, Winston N, Stocco C. Molecular crosstalk between insulin-like growth factors and follicle-stimulating hormone in the regulation of granulosa cell function. Reprod Med Biol 2024; 23:e12575. [PMID: 38571513 PMCID: PMC10988955 DOI: 10.1002/rmb2.12575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/11/2024] [Accepted: 03/20/2024] [Indexed: 04/05/2024] Open
Abstract
Background The last phase of folliculogenesis is driven by follicle-stimulating hormone (FSH) and locally produced insulin-like growth factors (IGFs), both essential for forming preovulatory follicles. Methods This review discusses the molecular crosstalk of the FSH and IGF signaling pathways in regulating follicular granulosa cells (GCs) during the antral-to-preovulatory phase. Main findings IGFs were considered co-gonadotropins since they amplify FSH actions in GCs. However, this view is not compatible with data showing that FSH requires IGFs to stimulate GCs, that FSH renders GCs sensitive to IGFs, and that FSH signaling interacts with factors downstream of AKT to stimulate GCs. New evidence suggests that FSH and IGF signaling pathways intersect at several levels to regulate gene expression and GC function. Conclusion FSH and locally produced IGFs form a positive feedback loop essential for preovulatory follicle formation in all species. Understanding the mechanisms by which FSH and IGFs interact to control GC function will help design new interventions to optimize follicle maturation, perfect treatment of ovulatory defects, improve in vitro fertilization, and develop new contraceptive approaches.
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Affiliation(s)
- Emily Hayes
- Department of Physiology and BiophysicsUniversity of Illinois Chicago College of MedicineChicagoIllinoisUSA
| | - Nicola Winston
- Department of Obstetrics and GynecologyUniversity of Illinois Chicago College of MedicineChicagoIllinoisUSA
| | - Carlos Stocco
- Department of Physiology and BiophysicsUniversity of Illinois Chicago College of MedicineChicagoIllinoisUSA
- Department of Obstetrics and GynecologyUniversity of Illinois Chicago College of MedicineChicagoIllinoisUSA
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Convissar S, Bennett-Toomey J, Stocco C. Insulin-like growth factor 1 enhances follicle-stimulating hormone-induced phosphorylation of GATA4 in rat granulosa cells. Mol Cell Endocrinol 2023; 559:111807. [PMID: 36279967 PMCID: PMC10041677 DOI: 10.1016/j.mce.2022.111807] [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: 09/11/2022] [Revised: 10/05/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022]
Abstract
Preovulatory granulosa cell (GC) differentiation is essential for the maturation and release of oocytes from the ovary. We have previously demonstrated that follicle-stimulating hormone (FSH) and insulin-like growth factors (IGFs) closely interact to control GC function. Similarly, we showed that GATA4 mediates FSH actions and it is required for preovulatory follicle formation. This report aimed to determine in vivo the effect of FSH on GATA4 phosphorylation and to investigate whether FSH and IGF1 interact to regulate GATA4 activity. In rat ovaries, treatment with equine chorionic gonadotropin (eCG) increased the phosphorylation of GATA4, which was confined to the nucleus of GCs. Using primary rat GCs, we observed that GATA4 phosphorylation at serine 105 increases the transcriptional activity of this transcription factor. Like FSH, IGF1 stimulated GATA4 phosphorylation at serine 105. Interestingly, GATA4 phosphorylation was significantly higher in cells cotreated with FSH and IGF1 when compared to FSH or IGF1 alone, suggesting that IGF1 augments the effects of FSH on GATA4. It was also found that the enhancing effect of IGF1 requires AKT activity and is mimicked by the inhibition of glycogen synthase kinase-3 β (GSK3β), suggesting that AKT inhibition of GSK3β may play a role in the regulation of GATA4 phosphorylation. The data support an important role of the IGF1/AKT/GSK3β signaling pathway in the regulation of GATA4 transcriptional activity and provide new insights into the mechanisms by which FSH and IGF1 regulate GC differentiation. Our findings suggest that GATA4 transcriptional activation may, at least partially, mediate AKT actions in GCs.
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Affiliation(s)
- Scott Convissar
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Jill Bennett-Toomey
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Carlos Stocco
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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Noor S, Mohammad T, Ashraf GM, Farhat J, Bilgrami AL, Eapen MS, Sohal SS, Yadav DK, Hassan MI. Mechanistic insights into the role of serum-glucocorticoid kinase 1 in diabetic nephropathy: A systematic review. Int J Biol Macromol 2021; 193:562-573. [PMID: 34715204 DOI: 10.1016/j.ijbiomac.2021.10.165] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/21/2021] [Accepted: 10/23/2021] [Indexed: 12/13/2022]
Abstract
Aberrant expression of serum-glucocorticoid kinase 1 (SGK1) contributes to the pathogenesis of multiple disorders, including diabetes, hypertension, obesity, fibrosis, and metabolic syndrome. SGK1 variant is expressed in the presence of insulin and several growth factors, eventually modulating various ion channels, carrier proteins, and transcription factors. SGK1 also regulates the enzymatic activity of Na+ K+ ATPase, glycogen synthase kinase-3, ubiquitin ligase Nedd4-2, and phosphomannose mutase impacting cell cycle regulation, neuroexcitation, and apoptosis. Ample evidence supports the crucial role of aberrant SGK1 expression in hyperglycemia-mediated secondary organ damage. Diabetic nephropathy (DN), a dreadful microvascular complication of diabetes, is the leading cause of end-stage renal failures with high morbidity and mortality rate. The complex pathogenesis of DN encompasses several influencing factors, including transcriptional factors, inflammatory markers, cytokines, epigenetic modulators, and abnormal enzymatic activities. SGK1 plays a pivotal role by controlling various physiological functions associated with the occurrence and progression of DN; therefore, targeting SGK1 may favorably influence the clinical outcome in patients with DN. This review aimed to provide mechanistic insights into SGK1 regulated DN pathogenesis and summarize the evidence supporting the therapeutic potential of SGK1 inhibition and its consequences on human health.
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Affiliation(s)
- Saba Noor
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Taj Mohammad
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Gulam M Ashraf
- Pre-Clinical Research Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Joviana Farhat
- College of Pharmacy, Al Ain University, Abu Dhabi 112612, United Arab Emirates
| | - Anwar L Bilgrami
- Deanship of Scientific Research, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Entomology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Mathew Suji Eapen
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania, Launceston, TAS, Australia
| | - Sukhwinder Singh Sohal
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania, Launceston, TAS, Australia
| | - Dharmendra Kumar Yadav
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro, Yeonsu-gu, Incheon City 21924, South Korea.
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
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Man L, Lustgarten Guahmich N, Kallinos E, Park L, Caiazza B, Khan M, Liu ZY, Patel R, Torres C, Lekovich J, Zhong L, Bodine R, Wen D, Zaninovic N, Schattman G, Rosenwaks Z, James D. Exogenous insulin-like growth factor 1 accelerates growth and maturation of follicles in human cortical xenografts and increases ovarian output in mice. F&S SCIENCE 2021; 2:237-247. [PMID: 35560275 PMCID: PMC9361175 DOI: 10.1016/j.xfss.2021.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 05/29/2023]
Abstract
OBJECTIVE To measure the influence of exogenous insulin-like growth factor 1 (IGF1) on follicle growth and maturation in human ovarian cortical xenografts. DESIGN Xenotransplantation model. SETTING University-based research laboratory. PATIENTS/ANIMALS Ovarian tissue was donated with consent and institutional review board approval by brain-dead organ donors or patients undergoing ovarian tissue cryopreservation for fertility preservation. Cortical fragments were transplanted into immunocompromised mice. INTERVENTIONS Cryopreserved ovarian cortical fragments from four women (aged 19, 25, 33, and 46 years) were transplanted into the gluteus muscle of immunocompromised mice in a fibrin matrix containing endothelial cells that were transduced with lentiviral particles encoding secreted IGF1. Xenografts were recovered after 3, 8, and 14 weeks. In addition, C57/Bl6 mice underwent intraovarian injection of saline or recombinant IGF1 (60 μg), followed by superovulation, analysis of ethynyl-deoxyuridine incorporation, and ribonucleic acid sequencing of the whole ovaries. MAIN OUTCOME MEASURES For xenografts: follicle count and distribution; antral follicle count; and corpora lutea/albicans count. For mice: follicle count and distribution; oocyte yield, ethynyl-deoxyuridine incorporation (granulosa cell proliferation); and ovarian transcriptomic signature. RESULTS At 3 weeks, xenografts in the IGF1 condition revealed a decreased percentage of primary follicles and increased percentage of secondary follicles that were concentrated in the preantral subtype; at 8 weeks, an increase in secondary follicles was concentrated in the simple subtype; after 14 weeks, primordial follicles were reduced, and while the number of advanced follicles did not power the experiment to demonstrate significance, antral follicles reduced and corpora lutea increased. Supporting experiments in mice revealed an increase in normal oocytes following intraovarian injection of recombinant IGF1 (60 μg) as well as increased proliferative index among follicles of secondary and preantral stages. Ribonucleic acid sequencing analysis of the whole ovaries following injection of recombinant IGF1 (25 μg) revealed an acute (24 hours) upregulation of transcripts related to steroidogenesis and luteinization. CONCLUSIONS Exogenous IGF1 advances the pace of growth among primordial, primary, and secondary stage follicles but results in near absence of antral stage follicles in long-term (14 weeks) xenografts. In mice, acute administration of IGF1 promotes follicle advance and increased oocyte yield. The results suggest that while superphysiological IGF1 alone advances the pace of growth among early/preantral follicles, a sustained and/or later-stage influence undermines antral follicle growth/survival or promotes premature luteinization. These findings provide a temporal framework for interpreting follicle growth/mobilization and may be useful in understanding the clinical application of human growth hormone in the context of assisted reproduction.
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Affiliation(s)
- Limor Man
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Nicole Lustgarten Guahmich
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Eleni Kallinos
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Laura Park
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Barbara Caiazza
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Monica Khan
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Zong-Ying Liu
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Ritaben Patel
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Carmen Torres
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Jovana Lekovich
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Liangwen Zhong
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Richard Bodine
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Duancheng Wen
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Nikica Zaninovic
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York; Tri-Institutional Stem Cell Derivation Laboratory, Weill Cornell Medicine, New York, New York
| | - Glenn Schattman
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Zev Rosenwaks
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York
| | - Daylon James
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine and Infertility, Weill Cornell Medicine, New York, New York; Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York; Tri-Institutional Stem Cell Derivation Laboratory, Weill Cornell Medicine, New York, New York.
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Guerriero I, Monaco G, Coppola V, Orlacchio A. Serum and Glucocorticoid-Inducible Kinase 1 (SGK1) in NSCLC Therapy. Pharmaceuticals (Basel) 2020; 13:ph13110413. [PMID: 33266470 PMCID: PMC7700219 DOI: 10.3390/ph13110413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/21/2022] Open
Abstract
Non-small cell lung cancer (NSCLC) remains the most prevalent and one of the deadliest cancers worldwide. Despite recent success, there is still an urgent need for new therapeutic strategies. It is also becoming increasingly evident that combinatorial approaches are more effective than single modality treatments. This review proposes that the serum and glucocorticoid-inducible kinase 1 (SGK1) may represent an attractive target for therapy of NSCLC. Although ubiquitously expressed, SGK1 deletion in mice causes only mild defects of ion physiology. The frequent overexpression of SGK1 in tumors is likely stress-induced and provides a therapeutic window to spare normal tissues. SGK1 appears to promote oncogenic signaling aimed at preserving the survival and fitness of cancer cells. Most importantly, recent investigations have revealed the ability of SGK1 to skew immune-cell differentiation toward pro-tumorigenic phenotypes. Future studies are needed to fully evaluate the potential of SGK1 as a therapeutic target in combinatorial treatments of NSCLC. However, based on what is currently known, SGK1 inactivation can result in anti-oncogenic effects both on tumor cells and on the immune microenvironment. A first generation of small molecules to inactivate SGK1 has already been already produced.
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Affiliation(s)
- Ilaria Guerriero
- Biogem Institute for Genetic Research Gaetano Salvatore, Ariano Irpino, 83031 Avellino, Italy; (I.G.); (G.M.)
| | - Gianni Monaco
- Biogem Institute for Genetic Research Gaetano Salvatore, Ariano Irpino, 83031 Avellino, Italy; (I.G.); (G.M.)
| | - Vincenzo Coppola
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
- Arthur G. James Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
- Correspondence: (V.C.); (A.O.); Tel.: +1-614-688-8038 (V.C.); +1-646-552-0641 (A.O.)
| | - Arturo Orlacchio
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
- Arthur G. James Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
- Correspondence: (V.C.); (A.O.); Tel.: +1-614-688-8038 (V.C.); +1-646-552-0641 (A.O.)
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8
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Richards JS. WOMEN IN REPRODUCTIVE SCIENCE: Discovering science and the ovary: a career of joy. Reproduction 2020; 158:F69-F80. [PMID: 30780130 DOI: 10.1530/rep-18-0513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 02/18/2019] [Indexed: 11/08/2022]
Abstract
My career has been about discovering science and learning the joys of the discovery process itself. It has been a challenging but rewarding process filled with many exciting moments and wonderful colleagues and students. Although I went to college to become a French major, I ultimately stumbled into research while pursuing a Masters Degree in teaching. Thus, my research career began in graduate school where I was studying NAD kinase in the ovary as a possible regulator of steroidogenesis, a big issue in the late 1960s. After a short excursion of teaching in North Dakota, I became a postdoctoral fellow at the University of Michigan, where radio-immuno assays and radio receptor assays had just come on the scene and were transforming endocrinology from laborious bioassays to quantitative science and of course these assays related to the ovary. From there I went to Baylor College of Medicine, a mecca of molecular biology, cloning genes and generating mouse models. It has been a fascinating and joyous journey.
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Affiliation(s)
- JoAnne S Richards
- Department of Molecular and Cellular Biology, Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas, USA
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9
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Lou Y, Zhang F, Luo Y, Wang L, Huang S, Jin F. Serum and Glucocorticoid Regulated Kinase 1 in Sodium Homeostasis. Int J Mol Sci 2016; 17:ijms17081307. [PMID: 27517916 PMCID: PMC5000704 DOI: 10.3390/ijms17081307] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/02/2016] [Accepted: 08/03/2016] [Indexed: 12/13/2022] Open
Abstract
The ubiquitously expressed serum and glucocorticoid regulated kinase 1 (SGK1) is tightly regulated by osmotic and hormonal signals, including glucocorticoids and mineralocorticoids. Recently, SGK1 has been implicated as a signal hub for the regulation of sodium transport. SGK1 modulates the activities of multiple ion channels and carriers, such as epithelial sodium channel (ENaC), voltage-gated sodium channel (Nav1.5), sodium hydrogen exchangers 1 and 3 (NHE1 and NHE3), sodium-chloride symporter (NCC), and sodium-potassium-chloride cotransporter 2 (NKCC2); as well as the sodium-potassium adenosine triphosphatase (Na+/K+-ATPase) and type A natriuretic peptide receptor (NPR-A). Accordingly, SGK1 is implicated in the physiology and pathophysiology of Na+ homeostasis. Here, we focus particularly on recent findings of SGK1’s involvement in Na+ transport in renal sodium reabsorption, hormone-stimulated salt appetite and fluid balance and discuss the abnormal SGK1-mediated Na+ reabsorption in hypertension, heart disease, edema with diabetes, and embryo implantation failure.
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Affiliation(s)
- Yiyun Lou
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou 310007, Zhejiang, China.
| | - Fan Zhang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Yuqin Luo
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Liya Wang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Shisi Huang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Fan Jin
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
- Key Laboratory of Reproductive Genetics, National Ministry of Education (Zhejiang University), Women's Reproductive Healthy Laboratory of Zhejiang Province, Hangzhou 310058, Zhejiang, China.
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Wilson K, Park J, Curry TE, Mishra B, Gossen J, Taniuchi I, Jo M. Core Binding Factor-β Knockdown Alters Ovarian Gene Expression and Function in the Mouse. Mol Endocrinol 2016; 30:733-47. [PMID: 27176614 DOI: 10.1210/me.2015-1312] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Core binding factor (CBF) is a heterodimeric transcription factor complex composed of a DNA-binding subunit, one of three runt-related transcription factor (RUNX) factors, and a non-DNA binding subunit, CBFβ. CBFβ is critical for DNA binding and stability of the CBF transcription factor complex. In the ovary, the LH surge increases the expression of Runx1 and Runx2 in periovulatory follicles, implicating a role for CBFs in the periovulatory process. The present study investigated the functional significance of CBFs (RUNX1/CBFβ and RUNX2/CBFβ) in the ovary by examining the ovarian phenotype of granulosa cell-specific CBFβ knockdown mice; CBFβ f/f * Cyp19 cre. The mutant female mice exhibited significant reductions in fertility, with smaller litter sizes, decreased progesterone during gestation, and fewer cumulus oocyte complexes collected after an induced superovulation. RNA sequencing and transcriptome assembly revealed altered expression of more than 200 mRNA transcripts in the granulosa cells of Cbfb knockdown mice after human chorionic gonadotropin stimulation in vitro. Among the affected transcripts are known regulators of ovulation and luteinization including Sfrp4, Sgk1, Lhcgr, Prlr, Wnt4, and Edn2 as well as many genes not yet characterized in the ovary. Cbfβ knockdown mice also exhibited decreased expression of key genes within the corpora lutea and morphological changes in the ovarian structure, including the presence of large antral follicles well into the luteal phase. Overall, these data suggest a role for CBFs as significant regulators of gene expression, ovulatory processes, and luteal development in the ovary.
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Affiliation(s)
- Kalin Wilson
- Department of Obstetrics and Gynecology (K.W., J.P., T.E.C., B.M., M.J.), Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298; Women's Health Department (J.G.), Merck Sharp and Dohme Research Laboratories, 5340-BH Oss, The Netherlands; and Laboratory for Transcriptional Regulation (I.T.), Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
| | - Jiyeon Park
- Department of Obstetrics and Gynecology (K.W., J.P., T.E.C., B.M., M.J.), Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298; Women's Health Department (J.G.), Merck Sharp and Dohme Research Laboratories, 5340-BH Oss, The Netherlands; and Laboratory for Transcriptional Regulation (I.T.), Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
| | - Thomas E Curry
- Department of Obstetrics and Gynecology (K.W., J.P., T.E.C., B.M., M.J.), Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298; Women's Health Department (J.G.), Merck Sharp and Dohme Research Laboratories, 5340-BH Oss, The Netherlands; and Laboratory for Transcriptional Regulation (I.T.), Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
| | - Birendra Mishra
- Department of Obstetrics and Gynecology (K.W., J.P., T.E.C., B.M., M.J.), Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298; Women's Health Department (J.G.), Merck Sharp and Dohme Research Laboratories, 5340-BH Oss, The Netherlands; and Laboratory for Transcriptional Regulation (I.T.), Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
| | - Jan Gossen
- Department of Obstetrics and Gynecology (K.W., J.P., T.E.C., B.M., M.J.), Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298; Women's Health Department (J.G.), Merck Sharp and Dohme Research Laboratories, 5340-BH Oss, The Netherlands; and Laboratory for Transcriptional Regulation (I.T.), Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
| | - Ichiro Taniuchi
- Department of Obstetrics and Gynecology (K.W., J.P., T.E.C., B.M., M.J.), Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298; Women's Health Department (J.G.), Merck Sharp and Dohme Research Laboratories, 5340-BH Oss, The Netherlands; and Laboratory for Transcriptional Regulation (I.T.), Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
| | - Misung Jo
- Department of Obstetrics and Gynecology (K.W., J.P., T.E.C., B.M., M.J.), Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298; Women's Health Department (J.G.), Merck Sharp and Dohme Research Laboratories, 5340-BH Oss, The Netherlands; and Laboratory for Transcriptional Regulation (I.T.), Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
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11
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Liu M, Yang KC, Dudley SC. Cardiac Sodium Channel Mutations: Why so Many Phenotypes? CURRENT TOPICS IN MEMBRANES 2016; 78:513-59. [PMID: 27586294 DOI: 10.1016/bs.ctm.2015.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The cardiac Na(+) channel (Nav1.5) conducts a depolarizing inward Na(+) current that is responsible for the generation of the upstroke Phase 0 of the action potential. In heart tissue, changes in Na(+) currents can affect conduction velocity and impulse propagation. The cardiac Nav1.5 is also involved in determination of the action potential duration, since some channels may reopen during the plateau phase, generating a persistent or late inward current. Mutations of cardiac Nav1.5 can induce gain or loss of channel function because of an increased late current or a decrease of peak current, respectively. Gain-of-function mutations cause Long QT syndrome type 3 and possibly atrial fibrillation, while loss-of-function channel mutations are associated with a wider variety of phenotypes, such as Brugada syndrome, cardiac conduction disease, dilated cardiomyopathy, and sick sinus node syndrome. The penetrance and phenotypes resulting from Nav1.5 mutations also vary with age, gender, body temperature, circadian rhythm, and between regions of the heart. This phenotypic variability makes it difficult to correlate genotype-phenotype. We propose that mutations are only one contributor to the phenotype and additional modifications on Nav1.5 lead to the phenotypic variability. Possible modifiers include other genetic variations and alterations in the life cycle of Nav1.5 such as gene transcription, RNA processing, translation, posttranslational modifications, trafficking, complex assembly, and degradation. In this chapter, we summarize potential modifiers of cardiac Nav1.5 that could help explain the clinically observed phenotypic variability. Consideration of these modifiers could help improve genotype-phenotype correlations and lead to new therapeutic strategies.
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Affiliation(s)
- M Liu
- The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - K-C Yang
- The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - S C Dudley
- The Warren Alpert Medical School of Brown University, Providence, RI, United States
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12
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Phosphorylation of FE65 Ser610 by serum- and glucocorticoid-induced kinase 1 modulates Alzheimer's disease amyloid precursor protein processing. Biochem J 2015; 470:303-17. [PMID: 26188042 PMCID: PMC4613528 DOI: 10.1042/bj20141485] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 07/17/2015] [Indexed: 01/15/2023]
Abstract
Phosphorylation of FE65 Ser610 by serum- and glucocorticoid-induced kinase 1 (SGK1) attenuates amyloid precursor protein (APP) processing via regulation of FE65–APP interaction. Alzheimer's disease (AD) is a fatal neurodegenerative disease affecting 36 million people worldwide. Genetic and biochemical research indicate that the excessive generation of amyloid-β peptide (Aβ) from amyloid precursor protein (APP), is a major part of AD pathogenesis. FE65 is a brain-enriched adaptor protein that binds to APP. However, the role of FE65 in APP processing and the mechanisms that regulate binding of FE65 to APP are not fully understood. In the present study, we show that serum- and glucocorticoid-induced kinase 1 (SGK1) phosphorylates FE65 on Ser610 and that this phosphorylation attenuates FE65 binding to APP. We also show that FE65 promotes amyloidogenic processing of APP and that FE65 Ser610 phosphorylation inhibits this effect. Furthermore, we found that the effect of FE65 Ser610 phosphorylation on APP processing is linked to a role of FE65 in metabolic turnover of APP via the proteasome. Thus FE65 influences APP degradation via the proteasome and phosphorylation of FE65 Ser610 by SGK1 regulates binding of FE65 to APP, APP turnover and processing.
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13
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Habig C, Geffers R, Distl O. Differential gene expression from genome-wide microarray analyses distinguishes Lohmann Selected Leghorn and Lohmann Brown layers. PLoS One 2012; 7:e46787. [PMID: 23056453 PMCID: PMC3466173 DOI: 10.1371/journal.pone.0046787] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 09/06/2012] [Indexed: 01/21/2023] Open
Abstract
The Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) layer lines have been selected for high egg production since more than 50 years and belong to the worldwide leading commercial layer lines. The objectives of the present study were to characterize the molecular processes that are different among these two layer lines using whole genome RNA expression profiles. The hens were kept in the newly developed small group housing system Eurovent German with two different group sizes. Differential expression was observed for 6,276 microarray probes (FDR adjusted P-value <0.05) among the two layer lines LSL and LB. A 2-fold or greater change in gene expression was identified on 151 probe sets. In LSL, 72 of the 151 probe sets were up- and 79 of them were down-regulated. Gene ontology (GO) enrichment analysis accounting for biological processes evinced 18 GO-terms for the 72 probe sets with higher expression in LSL, especially those taking part in immune system processes and membrane organization. A total of 32 enriched GO-terms were determined among the 79 down-regulated probe sets of LSL. Particularly, these terms included phosphorus metabolic processes and signaling pathways. In conclusion, the phenotypic differences among the two layer lines LSL and LB are clearly reflected in their gene expression profiles of the cerebrum. These novel findings provide clues for genes involved in economically important line characteristics of commercial laying hens.
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Affiliation(s)
- Christin Habig
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover (Foundation), Hannover, Germany
| | - Robert Geffers
- Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ottmar Distl
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover (Foundation), Hannover, Germany
- * E-mail:
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14
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Won M, Park KA, Byun HS, Kim YR, Choi BL, Hong JH, Park J, Seok JH, Lee YH, Cho CH, Song IS, Kim YK, Shen HM, Hur GM. Protein kinase SGK1 enhances MEK/ERK complex formation through the phosphorylation of ERK2: implication for the positive regulatory role of SGK1 on the ERK function during liver regeneration. J Hepatol 2009; 51:67-76. [PMID: 19447520 DOI: 10.1016/j.jhep.2009.02.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 01/06/2009] [Accepted: 02/04/2009] [Indexed: 12/13/2022]
Abstract
BACKGROUND/AIMS Based on the observation of biphasic induction of SGK1 expression in the regenerating liver, we investigated the role of SGK1 in the regulation of MEK/ERK signaling pathway which plays a crucial role in regulating growth and survival signaling. METHODS To determine the role of SGK1 in the activation of MEK/ERK signaling cascade, we infected primary hepatocytes with recombinant adenoviral vector encoding SGK1, and assessed its effect on the MEK/ERK signaling pathway. RESULTS Partial hepatectomy resulted in the biphasic transcriptional induction of SGK1 in regenerating liver tissues. Infection of primary hepatocytes with an adenoviral vector encoding SGK1 enhanced the ERK phosphorylation under serum-starved conditions and this was blocked by the expression of kinase-dead SGK1. SGK1 was found to physically interact with ERK1/2 as well as MEK1/2. Furthermore, SGK1 mediated the phosphorylation of ERK2 on Ser(29) in a serum-dependent manner. Replacement of Ser(29) to aspartic acid, which mimics the phosphorylation of Ser(29), enhanced the ERK2 activity as well as the MEK/ERK complexes formation. CONCLUSIONS SGK1 expression during liver regeneration is a part of a signaling pathway that is necessary for enhancing ERK signaling activation through modulating the MEK/ERK complex formation.
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Affiliation(s)
- Minho Won
- Department of Pharmacology, Research Institute for Medical Science, Infection Signaling Network Research Center, Daejeon Regional Cancer Center, College of Medicine, Chungnam National University, 6 Munhwa-dong, Jung-gu, Daejeon 301-131, Republic of Korea
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15
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Gomez-Sanchez EP, Gomez-Sanchez MT, de Rodriguez AF, Romero DG, Warden MP, Plonczynski MW, Gomez-Sanchez CE. Immunohistochemical demonstration of the mineralocorticoid receptor, 11beta-hydroxysteroid dehydrogenase-1 and -2, and hexose-6-phosphate dehydrogenase in rat ovary. J Histochem Cytochem 2009; 57:633-41. [PMID: 19255253 DOI: 10.1369/jhc.2009.953059] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
An IHC survey using several monoclonal antibodies against different portions of the rat mineralocorticoid receptor (MR) molecule demonstrated significant specific MR immunoreactivity in the ovary, prompting further study of the localization of MR and of determinants of extrinsic MR ligand specificity, 11beta-hydroxysteroid dehydrogenase (11beta-HSD) types 1 and 2, and hexose-6-phosphate dehydrogenase (H6PDH). MR expression (real-time RT-PCR and Western blot) did not differ significantly in whole rat ovaries at early diestrus, late diestrus, estrus, and a few hours after ovulation. MR immunostaining was most intense in corporal lutea cells, light to moderate in oocytes and granulosa cells, and least intense in theca cells. Light immunoreactivity for 11beta-HSD2 occurred in most cells, with some mural granulosa cells of mature follicles staining more strongly. The distribution of immunoreactivity for 11beta-HSD1 and H6PDH required to generate NADPH, the cofactor required for reductase activity of 11beta-HSD1, was similar, with the most-intense staining in the cytoplasm of corporal lutea and theca cells and light or no staining in the granulosa and oocytes. MR function in the ovary is as yet unclear, but distinct patterns of distribution of 11beta-HSD1 and -2 and H6PDH suggest that the ligand for MR activation in different cells of the ovary may be differentially regulated.
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Affiliation(s)
- Elise P Gomez-Sanchez
- Research Service, G.V. (Sonny) Montgomery Veterans Affairs Medical Center and Division of Endocrinology, Department of Medicine, The University of Mississippi Medical Center, Jackson, Mississippi, USA.
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16
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Sheng H, Sun T, Cong B, He P, Zhang Y, Yan J, Lu C, Ni X. Corticotropin-releasing hormone stimulates SGK-1 kinase expression in cultured hippocampal neurons via CRH-R1. Am J Physiol Endocrinol Metab 2008; 295:E938-46. [PMID: 18713960 DOI: 10.1152/ajpendo.90462.2008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Corticotropin-releasing hormone (CRH) has been shown to exhibit various functions in hippocampus. In the present study, we examined the effect of CRH on the expression of serum/glucocorticoid-inducible protein kinase-1 (SGK-1), a novel protein kinase, in primary cultured hippocampal neurons. A dose-dependent increase in mRNA and protein levels of SGK-1 as well as frequency of SGK-1-positive neurons occurred upon exposure to CRH (1 pmol/l to 10 nmol/l). These effects can be reversed by the specific CRH-R1 antagonist antalarmin but not by the CRH-R2 antagonist astressin 2B. Blocking adenylate cyclase (AC) activity with SQ22536 and PKA with H89 completely prevented CRH-induced mRNA and protein expression of SGK-1. Blockage of PLC or PKC did not block CRH-induced SGK-1 expression. Our results suggest that CRH act on CRH-R1 to stimulate SGK-1 mRNA and protein expression in cultured hippocampal neurons via a mechanism that is involved in AC/PKA signaling pathways.
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Affiliation(s)
- Hui Sheng
- Departments of Physiology, Second Military Medical University, Shanghai, China
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17
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Fan HY, Shimada M, Liu Z, Cahill N, Noma N, Wu Y, Gossen J, Richards JS. Selective expression of KrasG12D in granulosa cells of the mouse ovary causes defects in follicle development and ovulation. Development 2008; 135:2127-37. [PMID: 18506027 DOI: 10.1242/dev.020560] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Activation of the RAS family of small G-proteins is essential for follicle stimulating hormone-induced signaling events and the regulation of target genes in cultured granulosa cells. To analyze the functions of RAS protein in granulosa cells during ovarian follicular development in vivo, we generated conditional knock-in mouse models in which the granulosa cells express a constitutively active KrasG12D. The KrasG12D mutant mice were subfertile and exhibited signs of premature ovarian failure. The mutant ovaries contained numerous abnormal follicle-like structures that were devoid of mitotic and apoptotic cells and cells expressing granulosa cell-specific marker genes. Follicles that proceeded to the antral stage failed to ovulate and expressed reduced levels of ovulation-related genes. The human chorionic gonadotropin-stimulated phosphorylation of ERK1/2 was markedly reduced in mutant cells. Reduced ERK1/2 phosphorylation was due, in part, to increased expression of MKP3, an ERK1/2-specific phosphatase. By contrast, elevated levels of phospho-AKT were evident in granulosa cells of immature KrasG12D mice, even in the absence of hormone treatments, and were associated with the progressive decline of FOXO1 in the abnormal follicle-like structures. Thus, inappropriate activation of KRAS in granulosa cells blocks the granulosa cell differentiation pathway, leading to the persistence of abnormal non-mitotic, non-apoptotic cells rather than tumorigenic cells. Moreover, those follicles that reach the antral stage exhibit impaired responses to hormones, leading to ovulation failure. Transient but not sustained activation of RAS in granulosa cells is therefore crucial for directing normal follicle development and initiating the ovulation process.
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Affiliation(s)
- Heng-Yu Fan
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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18
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Rodrigues P, Limback D, McGinnis LK, Plancha CE, Albertini DF. Oogenesis: Prospects and challenges for the future. J Cell Physiol 2008; 216:355-65. [PMID: 18452183 DOI: 10.1002/jcp.21473] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Oogenesis serves a singular role in the reproductive success of plants and animals. Of their remarkable differentiation pathway what stands out is the ability of oocytes to transform from a single cell into the totipotent lineages that seed the early embryo. As our understanding that commonalities between diverse organisms at the genetic, cellular and molecular levels are conserved to achieve successful reproduction, the notion that embryogenesis presupposes oogenesis has entered the day-to-day parlance of regenerative medicine and stem cell biology. With emphasis on the mammalian oocyte, this review will cover (1) current concepts regarding the birth, survival and growth of oocytes that depends on complex patterns of cell communication between germ line and soma, (2) the notion of "maternal inheritance" from a genetic and epigenetic perspective, and (3) the relative value of model systems with reference to current clinical and biotechnology applications.
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Affiliation(s)
- P Rodrigues
- Department Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, USA
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19
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Buse P, Maiyar AC, Failor KL, Tran S, Leong MLL, Firestone GL. The stimulus-dependent co-localization of serum- and glucocorticoid-regulated protein kinase (Sgk) and Erk/MAPK in mammary tumor cells involves the mutual interaction with the importin-alpha nuclear import protein. Exp Cell Res 2007; 313:3261-75. [PMID: 17692313 PMCID: PMC3422670 DOI: 10.1016/j.yexcr.2007.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 06/21/2007] [Accepted: 07/03/2007] [Indexed: 01/04/2023]
Abstract
In Con8 rat mammary epithelial tumor cells, indirect immunofluorescence revealed that Sgk (serum- and glucocorticoid-regulated kinase) and Erk/MAPK (extracellular signal-regulated protein kinase/mitogen activated protein kinase) co-localized to the nucleus in serum-treated cells and to the cytoplasmic compartment in cells treated with the synthetic glucocorticoid dexamethasone. Moreover, the subcellular distribution of the importin-alpha nuclear transport protein was similarly regulated in a signal-dependent manner. In vitro GST-pull down assays revealed the direct interaction of importin-alpha with either Sgk or Erk/MAPK, while RNA interference knockdown of importin-alpha expression disrupted the localization of both Sgk and Erk into the nucleus of serum-treated cells. Wild type or kinase dead forms of Sgk co-immunoprecipitated with Erk/MAPK from either serum- or dexamethasone-treated mammary tumor cells, suggesting the existence of a protein complex containing both kinases. In serum-treated cells, nucleus residing Sgk and Erk/MAPK were both hyperphosphorylated, indicative of their active states, whereas, in dexamethasone-treated cells Erk/MAPK, but not Sgk, was in its inactive hypophosphorylated state. Treatment with a MEK inhibitor, which inactivates Erk/MAPK, caused the relocalization of both Sgk and ERK to the cytoplasm. We therefore propose that the signal-dependent co-localization of Sgk and Erk/MAPK mediated by importin-alpha represents a new pathway of signal integration between steroid and serum/growth factor-regulated pathways.
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Affiliation(s)
- Patricia Buse
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA 94720-3200, USA
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20
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Sandu C, Artunc F, Grahammer F, Rotte A, Boini KM, Friedrich B, Sandulache D, Metzger M, Just L, Mack A, Skutella T, Rexhepaj R, Risler T, Wulff P, Kuhl D, Lang F. Role of the serum and glucocorticoid inducible kinase SGK1 in glucocorticoid stimulation of gastric acid secretion. Pflugers Arch 2007; 455:493-503. [PMID: 17618452 DOI: 10.1007/s00424-007-0305-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 05/11/2007] [Accepted: 05/31/2007] [Indexed: 12/29/2022]
Abstract
Glucocorticoids stimulate gastric acid secretion, an effect favoring the development of peptic ulcers. Putative mechanisms involved include the serum- and glucocorticoid-inducible kinase (SGK1), which stimulates a variety of epithelial channels and transporters. The present study explored the contribution of SGK1 to effects of glucocorticoids on gastric acid secretion. In isolated gastric glands from gene-targeted mice lacking functional SGK1 (sgk1 (-/-)) and their wild-type littermates (sgk1 (+/+)), H(+)-secretion (DeltapH/min) was determined utilizing 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF)-fluorescence, SGK1 transcript levels by in situ hybdridization, and expression of KCNQ1 channels by immunohistochemistry and real-time polymerase chain reaction. SGK1 transcript levels were enhanced by a 4-day treatment with 10 mug/g body weight (BW)/day dexamethasone (DEX). Before treatment, DeltapH/min was similar in sgk1 (-/-) and sgk1 (+/+)mice. DEX increased DeltapH/min approximately fourfold in sgk1 (+/+)mice and approximately twofold in sgk1 (-/-)mice, effects abolished in the presence of K(+)/H(+)ATPase-inhibitor omeprazole (50 microM). Increase in local K(+) concentrations to 35 mM (replacing Na(+)) enhanced DeltapH/min, which could not be further stimulated by DEX and was not significantly different between sgk1 (-/-) and sgk1 (+/+)mice. Carbachol (100 microM) and forskolin (5 microM) stimulated gastric acid secretion to a similar extent in sgk1 (-/-) and sgk1 (+/+)mice. In conclusion, SGK1 is not required for basal and cyclic AMP-stimulated gastric H(+) secretion but participates in the stimulation of gastric H(+) secretion by glucocorticoids. The effects of glucocorticoids and SGK1 are not additive to an increase in extracellular K(+) concentration and may thus involve stimulation of K(+) channels.
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Affiliation(s)
- Ciprian Sandu
- Department of Physiology, University of Tuebingen, Tübingen, Germany
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Abstract
The corpus luteum (CL) is one of the few endocrine glands that forms from the remains of another organ and whose function and survival are limited in scope and time. The CL is the site of rapid remodeling, growth, differentiation, and death of cells originating from granulosa, theca, capillaries, and fibroblasts. The apparent raison d'etre of the CL is the production of progesterone, and all the structural and functional features of this gland are geared toward this end. Because of its unique importance for successful pregnancies, the mammals have evolved a complex series of checks and balances that maintains progesterone at appropriate levels throughout gestation. The formation, maintenance, regression, and steroidogenesis of the CL are among the most significant and closely regulated events in mammalian reproduction. During pregnancy, the fate of the CL depends on the interplay of ovarian, pituitary, and placental regulators. At the end of its life span, the CL undergoes a process of regression leading to its disappearance from the ovary and allowing the initiation of a new cycle. The generation of transgenic, knockout and knockin mice and the development of innovative technologies have revealed a novel role of several molecules in the reprogramming of granulosa cells into luteal cells and in the hormonal and molecular control of the function and demise of the CL. The current review highlights our knowledge on these key molecular events in rodents.
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Affiliation(s)
- Carlos Stocco
- Department of Obstetrics, Gynecology and Reproductive Science, Yale University School of Medicine, New Haven, CT 06510, USA
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22
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Han SJ, Vaccari S, Nedachi T, Andersen CB, Kovacina KS, Roth RA, Conti M. Protein kinase B/Akt phosphorylation of PDE3A and its role in mammalian oocyte maturation. EMBO J 2006; 25:5716-25. [PMID: 17124499 PMCID: PMC1698880 DOI: 10.1038/sj.emboj.7601431] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Accepted: 10/19/2006] [Indexed: 11/08/2022] Open
Abstract
cGMP-inhibited cAMP phosphodiesterase 3A (PDE3A) is expressed in mouse oocytes, and its function is indispensable for meiotic maturation as demonstrated by genetic ablation. Moreover, PDE3 activity is required for insulin/insulin-like growth factor-1 stimulation of Xenopus oocyte meiotic resumption. Here, we investigated the cAMP-dependent protein kinase B (PKB)/Akt regulation of PDE3A and its impact on oocyte maturation. Cell-free incubation of recombinant mouse PDE3A with PKB/Akt or cAMP-dependent protein kinase A catalytic subunits leads to phosphorylation of the PDE3A protein. Coexpression of PDE3A with constitutively activated PKB/Akt (Myr-Akt) increases PDE activity as well as its phosphorylation state. Injection of pde3a mRNA potentiates insulin-dependent maturation of Xenopus oocytes and rescues the phenotype of pde3(-/-) mouse oocytes. This effect is greatly decreased by mutation of any of the PDE3A serines 290-292 to alanine in both Xenopus and mouse. Microinjection of myr-Akt in mouse oocytes causes in vitro meiotic maturation and this effect requires PDE3A. Collectively, these data indicate that activation of PDE3A by PKB/Akt-mediated phosphorylation plays a role in the control of PDE3A activity in mammalian oocytes.
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Affiliation(s)
- Seung Jin Han
- Division of Reproductive Biology, Department of Obstetrics and Gynecology, Stanford University, Stanford, CA, USA
| | - Sergio Vaccari
- Division of Reproductive Biology, Department of Obstetrics and Gynecology, Stanford University, Stanford, CA, USA
| | - Taku Nedachi
- Tohoku University Biomedical Engineering Research Organization, Sendai, Japan
| | - Carsten B Andersen
- Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Kristina S Kovacina
- Department of Molecular Pharmacology, Stanford University, Stanford, CA, USA
| | - Richard A Roth
- Department of Molecular Pharmacology, Stanford University, Stanford, CA, USA
| | - Marco Conti
- Division of Reproductive Biology, Department of Obstetrics and Gynecology, Stanford University, Stanford, CA, USA
- Division of Reproductive Biology, Department of Obstetrics and Gynecology, Stanford University, 300 Pasteur dr., Stanford, CA 94305, USA. Tel.: +1 650 725 2452; Fax: +1 650 725 7102; E-mail:
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Lang F, Böhmer C, Palmada M, Seebohm G, Strutz-Seebohm N, Vallon V. (Patho)physiological significance of the serum- and glucocorticoid-inducible kinase isoforms. Physiol Rev 2006; 86:1151-78. [PMID: 17015487 DOI: 10.1152/physrev.00050.2005] [Citation(s) in RCA: 516] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The serum- and glucocorticoid-inducible kinase-1 (SGK1) is ubiquitously expressed and under genomic control by cell stress (including cell shrinkage) and hormones (including gluco- and mineralocorticoids). Similar to its isoforms SGK2 and SGK3, SGK1 is activated by insulin and growth factors via phosphatidylinositol 3-kinase and the 3-phosphoinositide-dependent kinase PDK1. SGKs activate ion channels (e.g., ENaC, TRPV5, ROMK, Kv1.3, KCNE1/KCNQ1, GluR1, GluR6), carriers (e.g., NHE3, GLUT1, SGLT1, EAAT1-5), and the Na+-K+-ATPase. They regulate the activity of enzymes (e.g., glycogen synthase kinase-3, ubiquitin ligase Nedd4-2, phosphomannose mutase-2) and transcription factors (e.g., forkhead transcription factor FKHRL1, beta-catenin, nuclear factor kappaB). SGKs participate in the regulation of transport, hormone release, neuroexcitability, cell proliferation, and apoptosis. SGK1 contributes to Na+ retention and K+ elimination of the kidney, mineralocorticoid stimulation of salt appetite, glucocorticoid stimulation of intestinal Na+/H+ exchanger and nutrient transport, insulin-dependent salt sensitivity of blood pressure and salt sensitivity of peripheral glucose uptake, memory consolidation, and cardiac repolarization. A common ( approximately 5% prevalence) SGK1 gene variant is associated with increased blood pressure and body weight. SGK1 may thus contribute to metabolic syndrome. SGK1 may further participate in tumor growth, neurodegeneration, fibrosing disease, and the sequelae of ischemia. SGK3 is required for adequate hair growth and maintenance of intestinal nutrient transport and influences locomotive behavior. In conclusion, the SGKs cover a wide variety of physiological functions and may play an active role in a multitude of pathophysiological conditions. There is little doubt that further targets will be identified that are modulated by the SGK isoforms and that further SGK-dependent in vivo physiological functions and pathophysiological conditions will be defined.
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Affiliation(s)
- Florian Lang
- Department of Physiology, University of Tuebingen, Tuebingen, Germany.
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24
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Arteaga MF, Wang L, Ravid T, Hochstrasser M, Canessa CM. An amphipathic helix targets serum and glucocorticoid-induced kinase 1 to the endoplasmic reticulum-associated ubiquitin-conjugation machinery. Proc Natl Acad Sci U S A 2006; 103:11178-83. [PMID: 16847254 PMCID: PMC1544061 DOI: 10.1073/pnas.0604816103] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Indexed: 01/13/2023] Open
Abstract
Serum- and glucocorticoid-induced kinase 1 (Sgk1) regulates many ion channels and transporters in epithelial cells and promotes cell survival under stress conditions. In this study we demonstrate that Sgk1 is a short-lived protein regulated by the endoplasmic reticulum (ER)-associated degradation system and subcellular localization to the ER. We identified a hydrophobic motif (residues 18-30) as the signal for ER localization and rapid degradation by the ubiquitin (Ub)/proteasome pathway in both yeast and mammalian cells. Deletion or reduction of hydrophobicity of the motif redistributes Sgk1 to the cytosol and nucleus and markedly increases its half-life. We determined that the Ub-conjugating UBC6 and UBC7 and the Ub ligase HRD1 are the ER-associated Ub enzymes that mediate degradation of Sgk1; thus, Sgk1 has been identified as a cytosolic substrate for mammalian HRD1. Compartmentalization of Sgk1 controls the functional and spatial specificities of Sgk1-mediated signaling pathways, whereas rapid protein turnover provides a means to rapidly adjust Sgk1 abundance in response to different hormonal and external stimuli that increase Sgk1 gene transcription.
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Affiliation(s)
| | - Lin Wang
- Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8026
| | - Tommer Ravid
- Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8026
| | - Mark Hochstrasser
- Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8026
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25
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Grahammer F, Henke G, Sandu C, Rexhepaj R, Hussain A, Friedrich B, Risler T, Metzger M, Just L, Skutella T, Wulff P, Kuhl D, Lang F. Intestinal function of gene-targeted mice lacking serum- and glucocorticoid-inducible kinase 1. Am J Physiol Gastrointest Liver Physiol 2006; 290:G1114-23. [PMID: 16410368 DOI: 10.1152/ajpgi.00231.2005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In vitro experiments have revealed the ability of serum- and glucocorticoid-inducible kinase 1 (SGK1) to stimulate intestinal Na(+)-coupled glucose cotransporter 1 (SGLT1) and intestinal Na(+)/H(+) exchanger 3 (NHE3). The present study explored the contribution of SGK1 to the regulation of intestinal transport in vivo. SGK1 transcript levels were determined by real-time PCR and glucose-induced currents (I(g)) reflecting SGLT1 activity by Ussing chamber experiments. BCECF fluorescence was utilized for the determination of Na(+)-dependent pH recovery from an ammonium pulse (DeltapH(NHE)) reflecting NHE activity. As a result, intestinal SGK1 transcript levels were significantly enhanced by a 4-day treatment with 10 microg.mg body wt(-1).day(-1) dexamethasone (Dex). I(g) was, under control conditions, virtually identical in sgk1 knockout mice (sgk1(-/-)) and their wild type littermates (sgk1(+/+)). A 4-day treatment with Dex, however, increased I(g) approximately threefold in sgk1(+/+) mice but not in sgk1(-/-) mice. DeltapH(NHE) was similar in sgk1(-/-) and sgk1(+/+) mice before treatment. Dex increased DeltapH(NHE) approximately threefold in sgk1(+/+) mice and approximately twofold in sgk1(-/-)mice, an effect significantly blunted in the presence of the specific NHE3 blocker S-3226 (10 microM). According to Western blot analysis, Dex significantly enhanced SGLT1 and NHE3 protein abundance in brush-border membranes of sgk1(+/+) mice but not of sgk1(-/-)mice. In conclusion, basic functions of SGLT1 and NHE3 in the intestine do not require stimulation by SGK1. However, the effects of glucocorticoids on SGLT1 are fully, and on NHE3 partially, dependent on SGK1.
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26
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David S, Stegenga SL, Hu P, Xiong G, Kerr E, Becker KB, Venkatapathy S, Warrington JA, Kalb RG. Expression of serum- and glucocorticoid-inducible kinase is regulated in an experience-dependent manner and can cause dendrite growth. J Neurosci 2006; 25:7048-53. [PMID: 16049181 PMCID: PMC6724837 DOI: 10.1523/jneurosci.0006-05.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The interaction of an animal with its environment during a critical period in early postnatal life has lifelong effects on the structure and function of sensory and motor systems. To gain insight into the molecular mechanisms of experience-dependent development, we challenged young rats to adapt to a new environment that engenders novel motor behavior. Rats born in the gravitational field (1G) of the earth subsequently were reared for 2 weeks either in the absence of gravity (microgravity) or at 1G. A comparison of gene expression using microarrays led to the identification of a panel of differentially regulated transcripts. We report here that the abundance of serum- and glucocorticoid-inducible kinase (SGK) is increased in spinal cord tissue from animals reared in microgravity in comparison with 1G-reared controls. The induction of SGK expression also can be achieved by administration of glucocorticoids to animals at 1G or neurons in vitro. Expression of constitutively active SGK in neurons leads to the elaboration of neuronal dendrites and their branching. Glucocorticoids also lead to dendrite elaboration, and this effect can be abrogated by inhibiting SGK activity. Changes in the level of expression of SGK could be part of the mechanism for experience-dependent acquisition of mature neuronal properties.
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Affiliation(s)
- Samuel David
- Department of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
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27
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Sandu C, Rexhepaj R, Grahammer F, McCormick JA, Henke G, Palmada M, Nammi S, Lang U, Metzger M, Just L, Skutella T, Dawson K, Wang J, Pearce D, Lang F. Decreased intestinal glucose transport in the sgk3-knockout mouse. Pflugers Arch 2005; 451:437-44. [PMID: 15971077 DOI: 10.1007/s00424-005-1474-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Accepted: 05/22/2005] [Indexed: 12/29/2022]
Abstract
Xenopus oocyte coexpression experiments revealed the capacity of the serum- and glucocorticoid-inducible kinase isoform 3 (SGK3) to up-regulate a variety of transport systems including the sodium-dependent glucose transporter SGLT1. The present study explored the functional significance of SGK3-dependent regulation of intestinal transport. To this end, experiments were performed in gene targeted mice lacking functional sgk3 (sgk3(-/-)) and their wild type littermates (sgk3(+/+)). Oral food intake and fecal dry weight were significantly larger in sgk3(-/-) than in sgk3(+/+) mice. Glucose-induced current (I(g)) in Ussing chamber as a measure of Na(+) coupled glucose transport was significantly smaller in sgk3(-/-) than in sgk3(+/+) mouse jejunal segments. Fasting plasma glucose concentrations were significantly lower in sgk3(-/-) than in sgk3(+/+) mice. Intestinal electrogenic transport of phenylalanine, cysteine, glutamine and proline were not significantly different between sgk3(-/-) and sgk3(+/+) mice. In conclusion, SGK3 is required for adequate intestinal Na(+) coupled glucose transport and impaired glucose absorption may contribute to delayed growth and decreased plasma glucose concentrations of SGK3 deficient mice. The hypoglycemia might lead to enhanced food intake to compensate for impaired intestinal absorption.
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Affiliation(s)
- Ciprian Sandu
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076 Tuebingen, Germany
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28
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Jo M, Gieske MC, Payne CE, Wheeler-Price SE, Gieske JB, Ignatius IV, Curry TE, Ko C. Development and application of a rat ovarian gene expression database. Endocrinology 2004; 145:5384-96. [PMID: 15297439 DOI: 10.1210/en.2004-0407] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The pituitary gonadotropins play a key role in follicular development and ovulation through the induction of specific genes. To identify these genes, we have constructed a genome-wide rat ovarian gene expression database (rOGED). The database was constructed from total RNA isolated from intact ovaries, granulosa cells, or residual ovarian tissues collected from immature pregnant mare serum gonadotropin (PMSG)/human chorionic gonadotropin-treated rats at 0 h (no PMSG), 12 h, and 48 h post PMSG, as well as 6 and 12 h post human chorionic gonadotropin. The total RNA was used for DNA microarray analysis using Affymetrix Rat Expression Arrays 230A and 230B (Affymetrix, Santa Clara, CA). The microarray data were compiled and used for display of individual gene expression profiles through specially developed software. The final rOGED provides immediate analysis of temporal gene expression profiles for over 28,000 genes in intact ovaries, granulosa cells, and residual ovarian tissue during follicular growth and the preovulatory period. The accuracy of the rOGED was validated against the gene profiles for over 20 known genes. The utility of the rOGED was demonstrated by identifying six genes that have not been described in the rat periovulatory ovary. The mRNA expression patterns and cellular localization for each of these six genes (estrogen sulfotransferase, synaptosomal-associated protein 25 kDa, runt-related transcription factor, calgranulin B, alpha1-macroglobulin, and MAPK phosphotase-3) were confirmed by Northern blot analyses and in situ hybridization, respectively. The current findings demonstrate that the rOGED can be used as an instant reference for ovarian gene expression profiles, as well as a reliable resource for identifying important yet, to date, unknown ovarian genes.
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Affiliation(s)
- Misung Jo
- Department of Clinical Sciences, University of Kentucky, Lexington, Kentucky 40536, USA
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29
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Dieter M, Palmada M, Rajamanickam J, Aydin A, Busjahn A, Boehmer C, Luft FC, Lang F. Regulation of glucose transporter SGLT1 by ubiquitin ligase Nedd4-2 and kinases SGK1, SGK3, and PKB. ACTA ACUST UNITED AC 2004; 12:862-70. [PMID: 15166308 DOI: 10.1038/oby.2004.104] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Serum- and glucocorticoid-inducible kinase 1 (SGK1) inhibits the ubiquitin ligase neuronal cell expressed developmentally downregulated 4-2 (Nedd4-2), which retards the retrieval of the epithelial Na+ channel ENaC. Accordingly, SGK1 enhances ENaC abundance in the cell membrane. The significance of this effect is shown by an association of an E8CC/CT;I6CC polymorphism in the SGK1 gene with increased blood pressure. However, strong expression of SGK1 in enterocytes not expressing ENaC points to further functions of SGK1. This study was performed to test for regulation of Na+-coupled glucose transporter 1 (SGLT1) by Nedd4-2, SGK1, and/or the related kinases SGK3 and PKB. Additional studies searched for an association of the SGK1 gene with BMI. RESEARCH METHODS AND PROCEDURES mRNA encoding SGLT1, wild-type Nedd4-2, inactive (C938S)Nedd4-2, wild type SGK1, constitutively active (S422D)SGK1 or inactive (K127N)SGK1, wild-type SGK3, and constitutively active (T308DS473D)PKB or inactive (T308AS473A)PKB were injected into Xenopus oocytes, and glucose transport was quantified from glucose-induced current (I(glc)). BMI was determined in individuals with or without the E8CC/CT;I6CC polymorphism. RESULTS I(glc) was significantly decreased by coexpression of Nedd4-2 but not of (C938S)Nedd4-2. Coexpression of SGK1, (S422D)SGK1, SGK3, or (T308DS473D)PKB, but not of (K127N)SGK1 or (T308AS473A)PKB, enhanced I(glc) and reversed the effect of Nedd4-2. SGK1 and SGK3 phosphorylated Nedd4-2. Deletion of the SGK/PKB phosphorylation sites in Nedd4-2 blunted the kinase effects. BMI was significantly (p < 0.008) greater in individuals with the E8CC/CT;I6CC polymorphism than in individuals without. DISCUSSION Overactivity of SGK1 may lead not only to excessive ENaC activity and hypertension but also to enhanced SGLT1 activity and obesity.
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Affiliation(s)
- Michael Dieter
- Department of Physiology I, University of Tübingen, Germany
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30
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Palmada M, Dieter M, Speil A, Böhmer C, Mack AF, Wagner HJ, Klingel K, Kandolf R, Murer H, Biber J, Closs EI, Lang F. Regulation of intestinal phosphate cotransporter NaPi IIb by ubiquitin ligase Nedd4-2 and by serum- and glucocorticoid-dependent kinase 1. Am J Physiol Gastrointest Liver Physiol 2004; 287:G143-50. [PMID: 15044175 DOI: 10.1152/ajpgi.00121.2003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Serum and glucocorticoid-inducible kinase 1 (SGK1) is highly expressed in enterocytes. The significance of the kinase in regulation of intestinal function has, however, remained elusive. In Xenopus laevis oocytes, SGK1 stimulates the epithelial Na(+) channel by phosphorylating the ubiquitin ligase Nedd4-2, which regulates channels by ubiquitination leading to subsequent degradation of the channel protein. Thus the present study has been performed to explore whether SGK1 regulates transport systems expressed in intestinal epithelial cells, specifically type IIb sodium-phosphate (Na(+)-P(i)) cotransporter (NaPi IIb). Immunohistochemistry in human small intestine revealed SGK1 colocalization with Nedd4-2 in villus enterocytes. For functional analysis cRNA encoding NaPi IIb, the SGK isoforms and/or the Nedd4-2 were injected into X. laevis oocytes, and transport activity was quantified as the substrate-induced current (I(P)). Exposure to 3 mM phosphate induces an I(P) in NaPi IIb-expressing oocytes. Coinjection of Nedd4-2, but not the catalytically inactive mutant (C938S)Nedd4-2, significantly downregulates I(P), whereas the coinjection of (S422D)SGK1 markedly stimulates I(P) and even fully reverses the effect of Nedd4-2 on I(P). The effect of (S422D)SGK1 on NaPi IIb is mimicked by wild-type SGK3 but not by wild-type SGK2, constitutively active (T308D,S473D)PKB, or inactive (K127N)SGK1. Moreover, (S422D)SGK1 and SGK3 phosphorylate Nedd4-2. In conclusion, SGK1 stimulates the NaPi IIb, at least in part, by phosphorylating and thereby inhibiting Nedd4-2 binding to its target. Thus the present study reveals a novel signaling pathway in the regulation of intestinal phosphate transport, which may be important for regulation of phosphate balance.
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Affiliation(s)
- M Palmada
- Physiologisches Institut, Universitat Tubingen, Gmelinstrasse 5, D-72076 Tubingen, Germany
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Coric T, Hernandez N, Alvarez de la Rosa D, Shao D, Wang T, Canessa CM. Expression of ENaC and serum- and glucocorticoid-induced kinase 1 in the rat intestinal epithelium. Am J Physiol Gastrointest Liver Physiol 2004; 286:G663-70. [PMID: 14630642 DOI: 10.1152/ajpgi.00364.2003] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Increase in epithelium sodium channel (ENaC) activity induced by aldosterone in the distal tubule of the kidney has been attributed to serum- and glucocorticoid-induced kinase 1 (sgk1). The distal colon constitutes another classical aldosterone-responsive epithelium that expresses both ENaC and sgk1 in an aldosterone-dependent manner. However, the site of expression and the temporal relationship of the aldosterone induction of these two proteins have not been investigated. Here, we examined the distribution and abundance of sgk1 in the rat intestine under basal conditions and after changes in the concentration of aldosterone and glucocorticoids. Results indicate that sgk1 is expressed in the distal colon and also in the ileum and jejunum. Abundance of sgk1 was high in control animals, and it did not change significantly after sodium depletion or after a single dose of aldosterone; however, it decreased after adrenalectomy. In contrast, the three subunits of ENaC were markedly induced in the distal colon by acute and chronic increases in aldosterone levels. Results indicate differential regulation of sgk and ENaC subunits by aldosterone in the distal colon. Distribution of sgk1 in the intestine beyond the aldosterone-responsive segments suggests that sgk1 may additionally regulate other sodium transporters in the intestinal epithelium.
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Affiliation(s)
- Tatjana Coric
- Department of Cellular and Molecular Psysiology, Yale University School of Medicine, New Haven, Connecticut 06520-8026, USA
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32
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Yang P, Roy SK. Follicle Stimulating Hormone-Induced DNA Synthesis in the Granulosa Cells of Hamster Preantral Follicles Involves Activation of Cyclin-Dependent Kinase-4 Rather Than Cyclin D2 Synthesis1. Biol Reprod 2004; 70:509-17. [PMID: 14561638 DOI: 10.1095/biolreprod.103.023457] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Although cyclin D2 mRNA synthesis precedes gonadotropin-induced DNA synthesis in quiescent granulosa cells in culture, it is unclear whether a similar mechanism exists for the granulosa cells of growing preantral follicles in cyclic animals. The objective was to evaluate whether the synthesis of cyclin D2 protein was a prerequisite for FSH-induced DNA synthesis in the granulosa cells of intact preantral follicles of cyclic hamsters. Preantral follicles from cyclic hamsters were cultured in the presence or absence of FSH, and cell cycle parameters were examined. FSH stimulated cyclin-dependent kinase (CDK)-4 activity by 2 h and DNA synthesis by 4 h without altering the levels of cyclin D2 in the granulosa cells. The FSH effect was mimicked by epidermal growth factor administered in vivo. Although FSH increased the levels of cyclin D2 mRNA, it also stimulated the degradation of cyclin D2 as well as p27(Kip1) and p19(INK4) proteins. FSH activation of CDK4 was mediated by cAMP and ERK-1/2. In contrast to granulosa cells in intact follicles, FSH or cAMP significantly increased cyclin D2 protein levels in cultured granulosa cells but failed to induce DNA synthesis. Collectively, these data suggest that granulosa cells of preantral follicles, which are destined to enter the S phase during the estrous cycle, contain necessary amounts of cyclin D2 and other G1 phase components. FSH stimulation results in the formation and activation of the cyclin D2/CDK4 complex leading to DNA synthesis. This mechanism may be necessary for rapid movement of follicles from preantral to antral stages during the short duration of the murine estrous cycle.
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Affiliation(s)
- Peixin Yang
- Departments of Obstetrics and Gynecology, University of Nebraska Medical Center, Omaha, Nebraska 68198-4515, USA
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Hsieh M, Mulders SM, Friis RR, Dharmarajan A, Richards JS. Expression and localization of secreted frizzled-related protein-4 in the rodent ovary: evidence for selective up-regulation in luteinized granulosa cells. Endocrinology 2003; 144:4597-606. [PMID: 12960062 DOI: 10.1210/en.2003-0048] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Secreted frizzled-related protein-4 (sFRP-4) belongs to a family of soluble proteins that have a Frizzled-like cysteine-rich domain and function as modulators of Wnt-Frizzled (Fz) signals. As several Wnts and Fz are expressed at defined stages of follicular development in rodent ovaries, these studies were undertaken to evaluate the hormone-regulated expression and localization of sFRP-4. In the mouse ovary, the expression of sFRP-4 mRNA was up-regulated in granulosa cells of large antral follicles after human chorionic gonadotropin administration and was also elevated in corpora lutea, as determined by RT-PCR and in situ hybridization analyses. In hypophysectomized rat ovaries, sFRP-4 expression was similarly induced by human chorionic gonadotropin and further up-regulated by PRL. PRL also stimulated the secretion of sFRP-4 protein from luteinized rat granulosa cells in culture. Therefore, regulation of sFRP-4 by LH and PRL may be important for modulating Fz-1, which is known to be expressed in periovulatory follicles, and Wnt-4/Fz-4, which are expressed in corpora lutea.
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Affiliation(s)
- Minnie Hsieh
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Russell DL, Doyle KMH, Gonzales-Robayna I, Pipaon C, Richards JS. Egr-1 induction in rat granulosa cells by follicle-stimulating hormone and luteinizing hormone: combinatorial regulation by transcription factors cyclic adenosine 3',5'-monophosphate regulatory element binding protein, serum response factor, sp1, and early growth response factor-1. Mol Endocrinol 2003; 17:520-33. [PMID: 12554779 DOI: 10.1210/me.2002-0066] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Early growth response factor (Egr-1) is an inducible zinc finger transcription factor that binds specific GC-rich enhancer elements and impacts female reproduction. These studies document for the first time that FSH rapidly induces Egr-1 expression in granulosa cells of small growing follicles. This response is transient but is reinitiated in preovulatory follicles exposed to the LH analog, human chorionic gonadotropin. Immunohistochemical analysis also showed gonadotropin induced Egr-1 in theca cells. The Egr-1 gene regulatory region responsive to gonadotropin signaling was localized within -164 bp of the transcription initiation site. Binding of Sp1/Sp3 to a proximal GC-box at -64/-46 bp was enhanced by FSH in immature granulosa cells but reduced after human chorionic gonadotropin stimulation of preovulatory follicles despite constant protein expression. This dynamic regulation of Sp1 binding was dependent on gonadotropin-regulated mechanisms that modulate Sp1/3-DNA binding activity. Serum response factor was active in granulosa cells and bound a consensus CArG-box/serum response element site, whereas two putative cAMP response elements within the -164-bp region bound cAMP regulatory element (CRE) binding protein (CREB) and a second cAMP-inducible protein immunologically related to CREB. Transient transfection analyses using Egr-1 promoter-luciferase constructs and site-specific mutations show that the serum response element, GC-box, and CRE-131 are involved in gonadotropin regulation of Egr-1 expression in granulosa cells. Specific kinase inhibitors of Erk or protein kinase A antagonized this induction while exogenously expressed Egr-1 enhanced reporter expression. These observations indicate that the Egr-1 gene is a target of both FSH and LH action that may mediate molecular programs of proliferation and/or differentiation during follicle growth, ovulation, and luteinization.
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Affiliation(s)
- Darryl L Russell
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
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35
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Maiyar AC, Leong MLL, Firestone GL. Importin-alpha mediates the regulated nuclear targeting of serum- and glucocorticoid-inducible protein kinase (Sgk) by recognition of a nuclear localization signal in the kinase central domain. Mol Biol Cell 2003; 14:1221-39. [PMID: 12631736 PMCID: PMC151592 DOI: 10.1091/mbc.e02-03-0170] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2002] [Revised: 10/17/2002] [Accepted: 11/17/2002] [Indexed: 12/19/2022] Open
Abstract
The transcriptionally regulated serum and glucocorticoid inducible protein kinase (Sgk) is localized to the nucleus in a serum-dependent manner, and a yeast two-hybrid genetic screen uncovered a specific interaction between Sgk and the importin-alpha nuclear import receptor. In vitro GST pull down assays demonstrated a strong and direct association of importin-alpha with endogenous Sgk and exogenously expressed HA-tagged Sgk, whereas both components coimmunoprecipitate and colocalize to the nucleus after serum stimulation. Consistent with an active mechanism of nuclear localization, the nuclear import of HA-Sgk in permeabilized cells required ATP, cytoplasm, and a functional nuclear pore complex. Ectopic addition of a 107 amino acid carboxy-terminal fragment of importin-alpha, which contains the Sgk binding region, competitively inhibited the ability of endogenous importin-alpha to import Sgk into nuclei in vitro. Mutagenesis of lysines by alanine substitution defined a KKAILKKKEEK sequence within the central domain of Sgk between amino acids 131-141 that functions as a nuclear localization signal (NLS) required for the in vitro interaction with importin-alpha and for nuclear import of full-length Sgk in cultured cells. The serum-induced nuclear import of Sgk requires the NLS-dependent recognition of Sgk by importin-alpha as well as the PI3-kinase-dependent phosphorylation of Sgk. Our results define a new role importin-alpha in the stimulus-dependent control of signal transduction by nuclear localized protein kinases.
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Affiliation(s)
- Anita C Maiyar
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, University of California at Berkeley, 94720-3200, USA
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36
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Abstract
The systemic actions of aldosterone are well documented; however, in comparison, our understanding of the cellular and molecular mechanisms by which aldosterone orchestrates these actions is rudimentary. Aldosterone exerts most of its physiological actions by modifying gene expression. It is now apparent that aldosterone represses almost as many genes as it induces. Several aldosterone-sensitive genes, including serum and glucocorticoid-inducible kinase (sgk) and small, monomeric Kirsten Ras GTP-binding protein (Ki-ras) have recently been identified. The molecular mechanisms and elements bestowing corticosteroid sensitivity on these and many other genes are becoming clear. Induction of Ki-Ras and Sgk is necessary and sufficient for some portion of aldosterone action in epithelia. These two signaling factors are components of a converging pathway with phosphatidylinositol 3-kinase positioned between them that enables both stabilizing the epithelial Na(+) channel (ENaC) in the open state as well as increasing the number of ENaC in the apical membrane. This aldosterone-induced signaling pathway contains many potential sites for feedback regulation and cross talk from other cascades and potentially impinges directly on the activity of transport proteins and/or cellular differentiation to modify electrolyte transport.
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Affiliation(s)
- James D Stockand
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio Texas 78229-3900, USA.
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37
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Hsieh M, Johnson MA, Greenberg NM, Richards JS. Regulated expression of Wnts and Frizzleds at specific stages of follicular development in the rodent ovary. Endocrinology 2002; 143:898-908. [PMID: 11861511 DOI: 10.1210/endo.143.3.8684] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Wnt ligands and Frizzled (Fz) G protein-coupled receptors impact cell fate, including embryonic development of the ovary. Because the role of these regulatory molecules during follicular development in the adult is not known, an RT-PCR survey was done. Wnt-4, Fz-4, and Fz-1 were among the transcripts detected, and each exhibited a specific pattern of expression. Fz-1 mRNA was low in preovulatory follicles of PMSG-treated mice but was increased within 4-12 h after an ovulatory surge of human CG. By in situ analysis, Fz-1 transcripts increased first in the theca cells and then in the granulosa cells of ovulating follicles but were low in corpora lutea. In contrast, Wnt-4, a critical factor in early ovarian development, was expressed in small preantral follicles. In addition, Wnt-4 was detected in preovulatory follicles and exhibited high levels in corpora lutea. A potential receptor for Wnt-4 in corpora lutea is Fz-4 that was also elevated in this tissue. Although Wnt-4 has been shown to function downstream of the PR in other tissues, Wnt-4 was not altered in follicles of PR-null mice that fail to ovulate. Rather expression of Fz-1 was lower in ovaries of PR knockout mice, compared with normal littermates. Thus, specific Wnt/Fz are expressed at distinct stages of follicular development, suggesting multiple functions for this signaling pathway in the ovary.
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MESH Headings
- Animals
- Blotting, Western
- Corpus Luteum/metabolism
- DNA Primers
- Female
- Frizzled Receptors
- Granulosa Cells/metabolism
- In Situ Hybridization
- Ligands
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Ovarian Follicle/physiology
- Ovary/metabolism
- Protein Biosynthesis
- Proteins/genetics
- Proto-Oncogene Proteins/biosynthesis
- Proto-Oncogene Proteins/genetics
- RNA, Messenger/biosynthesis
- RNA, Messenger/isolation & purification
- Rats
- Rats, Sprague-Dawley
- Receptors, Cell Surface
- Receptors, G-Protein-Coupled
- Receptors, Neurotransmitter/biosynthesis
- Receptors, Neurotransmitter/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription, Genetic
- Wnt Proteins
- Zebrafish Proteins
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Affiliation(s)
- Minnie Hsieh
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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38
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Richards JS, Sharma SC, Falender AE, Lo YH. Expression of FKHR, FKHRL1, and AFX genes in the rodent ovary: evidence for regulation by IGF-I, estrogen, and the gonadotropins. Mol Endocrinol 2002; 16:580-99. [PMID: 11875118 DOI: 10.1210/mend.16.3.0806] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Follicular development is dependent on both intraovarian growth regulatory factors, such as IGF-I and estrogen, as well as the pituitary gonadotropins, FSH and LH. Recently, we have shown that FSH impacts the IGF-I pathway via stimulation of the PI3K cascade leading to phosphorylation of protein kinase B (PKB)/Akt and the PKB-related kinase, Sgk. This study was undertaken to determine if during ovarian follicular development FSH regulates putative targets of PKB and Sgk, namely specific Forkhead transcription factor family members. Using in vivo and in vitro mouse and rat models, we show 1) that FKHR [Forkhead homolog of rhabdomysarcoma = Forkhead box binding protein (Foxo1), FKHRL1 (Forkhead-like protein-1 = Foxo3), and AFX (a Forkhead transcription factor = Foxo4); all defined according to the Human and Mouse Gene Nomenclature Committee) are expressed in the rodent ovary and 2) that FSH regulates transcription of the FKHR gene as well as phosphorylation of FKHR protein. Specifically, FSH/PMSG (primarily via E2) enhance expression of the FKHR gene in granulosa cells of developing follicles. Furthermore, E2 enhances expression of other IGF-I pathway components (IGF-1Rbeta and Glut-1), and IGF-I enhances expression of ERbeta, indicating that these two hormones comprise an autocrine regulatory network within growing follicles. In contrast, FSH and LH/human CG (via cAMP, PKA, and PI3K pathways) terminate FKHR expression as granulosa cells differentiate to luteal cells. In naïve granulosa cells, both FSH and IGF-I stimulate rapid phosphorylation of FKHR at multiple sites causing its redistribution from the nucleus to the cytoplasm in a PI3K-dependent manner. However, the effects of FSH and IGF-I differ markedly in differentiated granulosa cells in which FSH (but not IGF-I) induces Sgk and enhances phosphorylation of FKHR, PKB, and Sgk. The elevated expression of FKHR in granulosa cells of growing follicles indicates that FKHR may be linked to the proliferation of granulosa cells and that its phosphorylation by FSH, IGF-I, and other factors may impact its functional activity in this process. Thus, as a target of FSH (cAMP), E2 and IGF-I signaling in granulosa cells, FKHR likely coordinates numerous cell survival mechanisms.
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Affiliation(s)
- JoAnne S Richards
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
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39
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Affiliation(s)
- Jennifer R Wood
- Center for Research on Reproduction and Women's Health, University of Pennsylvania Medical Center, Philadelphia, PA 19104, USA
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40
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Lang F, Cohen P. Regulation and physiological roles of serum- and glucocorticoid-induced protein kinase isoforms. SCIENCE'S STKE : SIGNAL TRANSDUCTION KNOWLEDGE ENVIRONMENT 2001; 2001:re17. [PMID: 11707620 DOI: 10.1126/stke.2001.108.re17] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Serum- and glucocorticoid-induced protein kinase 1 (SGK1) was identified in 1993 as an immediate early gene whose mRNA levels increase dramatically within 30 minutes when cells are exposed to serum or glucocorticoids, or both. Subsequently, many other agonists, acting through a variety of signal transduction pathways, have been shown to induce SGK1 gene transcription in cells and tissues. SGK1 is a member of the "AGC" subfamily, which includes protein kinases A, G, and C, and its catalytic domain is most similar to protein kinase B (PKB). Like PKB, SGK1 is activated by phosphorylation in response to signals that stimulate phosphatidylinositol 3-kinase, and this is mediated by 3-phosphoinositide-dependent protein kinase 1 (PDK1) and another protein kinase that has yet to be identified. Thus, SGK1 is remarkable in being activated at both the transcriptional and posttranslational levels by a huge number of extracellular signals. In contrast, little is known about the transcriptional regulation of the two closely related isoforms SGK2 and SGK3, although they can be activated by phosphorylation. The substrate specificity of SGK isoforms superficially resembles that of PKB in that serine and threonine residues lying in Arg-Xaa-Arg-Xaa-Xaa-Ser/Thr sequences (where Xaa is a variable amino acid) are phosphorylated. However, although they may have some substrates in common, evidence is emerging that SGK1 and PKB phosphorylate distinct proteins and have different functions in vivo. In particular, SGK1 plays an important role in activating certain potassium, sodium, and chloride channels, suggesting an involvement in the regulation of processes such as cell survival, neuronal excitability, and renal sodium excretion. Moreover, sustained high levels of SGK1 protein and activity may contribute to conditions such as hypertension and diabetic nephropathy. This raises the possibility that specific inhibitors of SGK1 may have therapeutic potential for the treatment of several diseases.
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Affiliation(s)
- F Lang
- Department of Physiology, University of Tubingen, Germany.
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41
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Black AR, Black JD, Azizkhan-Clifford J. Sp1 and krüppel-like factor family of transcription factors in cell growth regulation and cancer. J Cell Physiol 2001; 188:143-60. [PMID: 11424081 DOI: 10.1002/jcp.1111] [Citation(s) in RCA: 830] [Impact Index Per Article: 36.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Sp/KLF family contains at least twenty identified members which include Sp1-4 and numerous krüppel-like factors. Members of the family bind with varying affinities to sequences designated as 'Sp1 sites' (e.g., GC-boxes, CACCC-boxes, and basic transcription elements). Family members have different transcriptional properties and can modulate each other's activity by a variety of mechanisms. Since cells can express multiple family members, Sp/KLF factors are likely to make up a transcriptional network through which gene expression can be fine-tuned. 'Sp1 site'-dependent transcription can be growth-regulated, and the activity, expression, and/or post-translational modification of multiple family members is altered with cell growth. Furthermore, Sp/KLF factors are involved in many growth-related signal transduction pathways and their overexpression can have positive or negative effects on proliferation. In addition to growth control, Sp/KLF factors have been implicated in apoptosis and angiogenesis; thus, the family is involved in several aspects of tumorigenesis. Consistent with a role in cancer, Sp/KLF factors interact with oncogenes and tumor suppressors, they can be oncogenic themselves, and altered expression of family members has been detected in tumors. Effects of changes in Sp/KLF factors are context-dependent and can appear contradictory. Since these factors act within a network, this diversity of effects may arise from differences in the expression profile of family members in various cells. Thus, it is likely that the properties of the overall network of Sp/KLF factors play a determining role in regulation of cell growth and tumor progression.
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Affiliation(s)
- A R Black
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, New York 14263, USA.
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42
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Burns KH, Yan C, Kumar TR, Matzuk MM. Analysis of ovarian gene expression in follicle-stimulating hormone beta knockout mice. Endocrinology 2001; 142:2742-51. [PMID: 11415992 DOI: 10.1210/endo.142.7.8279] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
FSH is a heterodimeric glycoprotein hormone that is produced in the gonadotroph cells of the anterior pituitary. It acts on Sertoli cells of the testis and granulosa cells of the ovary. We previously demonstrated that FSHbeta knockout female mice are infertile due to a block in folliculogenesis preceding antral stage development. To investigate aberrations of ovarian gene regulation in the absence of FSH, we analyzed the expression of several important marker genes using Northern blot and in situ hybridization techniques. Key findings are as follows: 1) Follicles of FSHbeta knockout mice develop a well organized thecal layer, which is positive for P450 17alpha-hydroxylase and LH receptor messenger RNAs (mRNAs). This indicates that theca recruitment is completed autonomously with respect to FSH. 2) Granulosa cells in FSH-deficient mice demonstrate an increase in FSH receptor mRNA, and decreases in P450 aromatase, serum/glucocorticoid-induced kinase, and inhibin/activin subunit mRNAs. These data support studies that implicate FSH signaling cascades in the expression of these genes. 3) In contrast to the thecal layer, granulosa cell populations in FSHbeta knockout mice do not accumulate LH receptor mRNA. This suggests that although the granulosa cells have a block in proliferation at the antral follicle stage in the absence of FSH, they do not initiate programs of terminal differentiation as seen in luteinizing cells of wild-type ovaries. 4) Ovaries of FSH-deficient mice demonstrate a modest decrease in cyclin D2 mRNA, without up-regulation of cell cycle inhibitor mRNAs associated with luteinization (i.e. p15, p27, and p21). Although components of the FSH null phenotype may be caused by partial cyclin D2 loss of function, these findings indicate that the mechanisms of granulosa cell cycle arrest in FSHbeta knockout mice are distinct from those of cycle withdrawal at luteinization. Underscoring the usefulness of the FSH-deficient mouse model, this study clarifies aspects of gonadotropin-dependent folliculogenesis, thecal layer development, cycle control in granulosa cells, and luteinization.
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Affiliation(s)
- K H Burns
- Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, USA
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43
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Affiliation(s)
- J S Richards
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
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44
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Richards JS. New signaling pathways for hormones and cyclic adenosine 3',5'-monophosphate action in endocrine cells. Mol Endocrinol 2001; 15:209-18. [PMID: 11158328 DOI: 10.1210/mend.15.2.0606] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The glycoprotein hormones, ACTH, TSH, FSH, and LH regulate diverse functions in endocrine cells. Although cAMP and PKA have long been shown to mediate specific intracellular signaling events including the transcription of specific genes via the CREB-CBP complex, recent observations have indicated that PKA does not account for all of the intracellular targets of cAMP. For example, TSH stimulation of thyroid cell proliferation is not completely blocked by PKA inhibitors. TSH and FSH can stimulate PKB phosphorylation by a PKAindependent but PI3-K/PDK1-dependent pathway. An FSH inducible kinase, Sgk, has recently been shown to be a close relative of PKB. Sgk is also a target of PI3-K-PDK1 pathway, indicating that some effects previously ascribed to PKB may be mediated by this inducible kinase. The identification of novel cAMP-binding proteins that exhibit guanine nucleotide exchange (GEF) activity (cAMP-GEFS; Epacs) has open new doors for cAMP action that include activation of small GTPases such as Rap1a, Rap2, and possibly Ras. These GTPases are known activators of downstream kinase cascades, including p38MAPK and Erk1/2 as well as PI3-K. Thus, FSH and TSH activation of PKB and Sgk may occur via this alternative cAMP pathway that involves cAMP-GEFs and the activation of the PI3-K/PDK1 pathway.
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Affiliation(s)
- J S Richards
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030-3498, USA.
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45
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Affiliation(s)
- JoAnne S. Richards
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030;
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46
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Sharma SC, Richards JS. Regulation of AP1 (Jun/Fos) factor expression and activation in ovarian granulosa cells. Relation of JunD and Fra2 to terminal differentiation. J Biol Chem 2000; 275:33718-28. [PMID: 10934195 DOI: 10.1074/jbc.m003555200] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
AP1 transcription factors control rapid responses of mammalian cells to stimuli that impact proliferation, differentiation, and transformation. To determine which AP1 factors are present in and regulated by hormones in ovarian cells during specific stages of proliferation and differentiation, we used both in vitro and in vivo models, Western blotting, immunohistochemistry, DNA binding assays, and transfections of AP1 promoter-reporter constructs. The expression patterns of Jun and Fos family members in response to hormones (follicle-stimulating hormone (FSH), luteinizing hormone (LH), and cAMP) were distinct. JunB, c-Jun, c-Fos, and Fra2 were rapidly but transiently induced by FSH in immature granulosa cells. JunD and Fra2 were induced by LH and maintained as granulosa cells terminally differentiated into luteal cells. Forskolin and phorbol myristate acetate acted synergistically to enhance transcription of an AP1(-73COL)-luciferase construct. JunD appears to be one mediator of this effect, since JunD was a major component of the AP1-DNA binding complex in granulosa cells, and menin, a selective inhibitor of JunD, blocked transcription of -73COL-luciferase. Thus, FSH and LH via cAMP induce specific AP1 factors, the AP1 expression patterns are distinct, and that of JunD and Fra2 correlates with the transition of proliferating granulosa cells to terminally differentiated, non-dividing luteal cells.
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Affiliation(s)
- S C Sharma
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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