1
|
Sullivan KM, Kriegel AJ. Growth hormone in pediatric chronic kidney disease: more than just height. Pediatr Nephrol 2024:10.1007/s00467-024-06330-8. [PMID: 38607423 DOI: 10.1007/s00467-024-06330-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/24/2024] [Accepted: 02/09/2024] [Indexed: 04/13/2024]
Abstract
Recombinant human growth hormone therapy, which was introduced in the 1980s, is now routine for children with advanced chronic kidney disease (CKD) who are exhibiting growth impairment. Growth hormone usage remains variable across different centers, with some showing low uptake. Much of the focus on growth hormone supplementation has been on increasing height because of social and psychological effects of short stature. There are, however, numerous other changes that occur in CKD that have not received as much attention but are biologically important for pediatric growth and development. This article reviews the current knowledge about the multisystem effects of growth hormone therapy in pediatric patients with CKD and highlights areas where additional clinical research is needed. We also included clinical data on children and adults who had received growth hormone for other indications apart from CKD. Ultimately, having robust clinical studies which examine these effects will allow children and their families to make more informed decisions about this therapy.
Collapse
Affiliation(s)
- Katie Marie Sullivan
- Division of Nephrology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Alison J Kriegel
- Division of Nephrology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA.
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA.
| |
Collapse
|
2
|
Zhao L, Jia D, Tan Z, Jiang H. Association of growth hormone deficiency with an increased number of preadipocytes in subcutaneous fat. Front Endocrinol (Lausanne) 2023; 14:1199589. [PMID: 37305046 PMCID: PMC10250704 DOI: 10.3389/fendo.2023.1199589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023] Open
Abstract
The inhibitory effect of growth hormone (GH) on adipose tissue growth is well known, but the underlying mechanism is not fully understood. In this study, we determined the possibility that GH inhibits adipose tissue growth by inhibiting adipogenesis, the process of formation of adipocytes from stem cells, in the lit/lit mice. The lit/lit mice are GH deficient because of a spontaneous mutation to the GH releasing hormone receptor (ghrhr) gene, and they have more subcutaneous fat despite being smaller than the lit/+ mice at the same age. We found that cells of the stromal vascular fraction (SVF) of subcutaneous fat from the lit/lit mice had greater adipogenic potential than those from the lit/+ mice, as evidenced by forming greater numbers of lipid droplets-containing adipocytes and having greater expression of adipocyte marker genes during induced adipocyte differentiation in culture. However, addition of GH to the culture did not reverse the superior adipogenic potential of subcutaneous SVF from the lit/lit mice. Through florescence-activated cell sorting and quantification of mRNAs of preadipocyte markers, including CD34, CD29, Sca-1, CD24, Pref-1, and PPARγ, we found that subcutaneous SVF from the lit/lit mice contained more preadipocytes than that from the lit/+ mice. These results support the notion that GH inhibits adipose tissue growth in mice at least in part by inhibiting adipogenesis. Furthermore, these results suggest that GH inhibits adipogenesis in mice not by inhibiting the terminal differentiation of preadipocytes into adipocytes, rather by inhibiting the formation of preadipocytes from stem cells or the recruitment of stem cells to the fat depot.
Collapse
|
3
|
Li T, Bai H, Fang H, Yang L, Yan P. Growth hormone inhibits adipogenic differentiation and induces browning in bovine subcutaneous adipocytes. Growth Horm IGF Res 2022; 66:101498. [PMID: 36007464 DOI: 10.1016/j.ghir.2022.101498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022]
Abstract
OBJECTIVE It is well established that growth hormone (GH) has the ability to stimulate lipolysis. The effects of GH on adipocyte differentiation and browning have not been clearly described. Therefore, the present study aimed to elucidate the role of GH in the differentiation and browning of bovine subcutaneous adipocytes as well as its underlying molecular mechanisms. METHODS We first treated bovine subcutaneous preadipocytes with different concentrations (0, 10, 100, and 500 ng/mL) of GH for 8 days and measured lipid accumulation and gene expression. Afterward, we treated preadipocytes and mature adipocytes with 500 ng/mL GH and determined differentiation and browning-related indicators. Finally, we investigated the expression of STAT5B in both preadipocytes and mature adipocytes after GH treatment. RESULTS We demonstrated that GH inhibited lipid accumulation and decreased the expression levels of adipogenic key genes (SCD1, SREBP1, PPARγ, and CEBPα) during adipocyte differentiation. Moreover, we observed that the inhibitory effect of GH on the early stage of adipocyte differentiation (0-2 days) was stronger than that on the later stage of adipocyte differentiation (2-8 days). We also found that GH promoted the expression levels of browning-related genes such as uncoupling protein 1 (UCP1) in mature adipocytes. Concurrently, GH promoted mitochondrial biogenesis and increased the expression levels of mitochondrial biogenesis-related genes. In addition, GH promoted phosphorylation of signal transducers and activator of transcription 5 b (STAT5B) and contributed to translocation of STAT5B to nucleus. After blocking the expression of STAT5B protein, GH weakened the inhibition of adipogenic key genes and reduced the promotion of browning-related genes in bovine subcutaneous adipocytes. CONCLUSIONS GH can inhibit adipocyte differentiation and promote adipocyte browning by regulating STAT5B in bovine subcutaneous adipocytes.
Collapse
Affiliation(s)
- Tingting Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Hui Bai
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Haoyuan Fang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Liang Yang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Peishi Yan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
| |
Collapse
|
4
|
Abstract
DLK1 is a maternally imprinted, paternally expressed gene coding for the transmembrane protein Delta-like homologue 1 (DLK1), a non-canonical NOTCH ligand with well-described roles during development, and tumor-supportive functions in several aggressive cancer forms. Here, we review the many functions of DLK1 as a regulator of stem cell pools and tissue differentiation in tissues such as brain, muscle, and liver. Furthermore, we review recent evidence supporting roles for DLK1 in the maintenance of aggressive stem cell characteristics of tumor cells, specifically focusing on central nervous system tumors, neuroblastoma, and hepatocellular carcinoma. We discuss NOTCH -dependent as well as NOTCH-independent functions of DLK1, and focus particularly on the complex pattern of DLK1 expression and cleavage that is finely regulated from a spatial and temporal perspective. Progress in recent years suggest differential functions of extracellular, soluble DLK1 as a paracrine stem cell niche-secreted factor, and has revealed a role for the intracellular domain of DLK1 in cell signaling and tumor stemness. A better understanding of DLK1 regulation and signaling may enable therapeutic targeting of cancer stemness by interfering with DLK1 release and/or intracellular signaling.
Collapse
Affiliation(s)
- Elisa Stellaria Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Alexander Pietras
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| |
Collapse
|
5
|
Sze L, Tschopp O, Neidert MC, Bernays RL, Ghirlanda C, Zwimpfer C, Wiesli P, Schmid C. Soluble delta-like 1 homolog decreases in patients with acromegaly following pituitary surgery: A potential mediator of adipogenesis suppression by growth hormone? Growth Horm IGF Res 2019; 45:20-24. [PMID: 30818110 DOI: 10.1016/j.ghir.2019.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/23/2019] [Accepted: 02/16/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVE GH excess in acromegaly leads to lower fat mass and insulin resistance; both reverse following pituitary surgery. Soluble delta like-1 homolog (sDlk1) inhibits adipocyte differentiation and may mediate the antiadipogenic effects of GH. It is released into the circulation by ectodomain shedding through 'A Disintegrin And Metalloproteinase domain 17' (ADAM17), which also sheds soluble α-Klotho (sKlotho). Klotho is a transmembrane protein, which influences life span. sKlotho inhibits insulin signalling, and is markedly elevated in acromegaly and decreases after surgery. Therefore, we examined if sDlk1 parallels the course of sKlotho, which could explain the well-known changes in fat mass in patients with acromegaly after surgery. DESIGN We measured serum levels of GH, IGF-1, sDlk1 and sKlotho (both by ELISA) in 42 treatment-naïve acromegaly patients (20 females/22 males) before and 1-3 months after transsphenoidal surgery. Data are presented as median(interquartile range). RESULTS GH decreased in all patients postoperatively (in 32/42 to <1 ng/ml during oral glucose tolerance testing). Likewise, IGF-1 and sKlotho decreased in all patients, from 587 (432-708) to 195 (133-270) ng/ml, and from 4.0 (2.7-5.9) to 0.7 (0.6-1.2) ng/ml, respectively; sDlk1 fell in 40/42 subjects, from 10.7 (5.8-13.4) to 7.1 (3.7-10.4) ng/ml following pituitary surgery. P < 0.0001 for all parameters. CONCLUSIONS sDlk1 declined after pituitary surgery in our patients with acromegaly, but to a lesser extent than sKlotho. It remains to be seen whether this may contribute to the well-known postoperative changes in body composition. Our findings may extend beyond the scope of acromegaly, and thus further elucidate mechanisms in the fields of obesity and anti-ageing.
Collapse
Affiliation(s)
- Lisa Sze
- Division of Endocrinology and Diabetology, Kantonsspital Winterthur, Brauerstrasse 15, CH-8401 Winterthur, Switzerland; Division of Endocrinology and Diabetology, University Hospital Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland.
| | - Oliver Tschopp
- Division of Endocrinology and Diabetology, University Hospital Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland.
| | - Marian C Neidert
- Department of Neurosurgery, University Hospital Zurich, Frauenklinikstrasse 10, CH-8091 Zurich, Switzerland.
| | - René L Bernays
- Department of Neurosurgery, University Hospital Zurich, Frauenklinikstrasse 10, CH-8091 Zurich, Switzerland; Department of Neurosurgery, Klinik Hirslanden, Witellikerstrasse 40, CH-8032 Zurich, Switzerland.
| | - Claudia Ghirlanda
- Division of Endocrinology and Diabetology, University Hospital Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland.
| | - Cornelia Zwimpfer
- Division of Endocrinology and Diabetology, University Hospital Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland.
| | - Peter Wiesli
- Division of Endocrinology and Diabetology, Kantonsspital Frauenfeld, Pfaffenholzstrasse 4, CH-8501 Frauenfeld, Switzerland.
| | - Christoph Schmid
- Division of Endocrinology and Diabetology, University Hospital Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland.
| |
Collapse
|
6
|
Cho YL, Park JG, Kang HJ, Kim W, Cho MJ, Jang JH, Kwon MG, Kim S, Lee SH, Lee J, Kim YG, Park YJ, Kim WK, Bae KH, Kwon BM, Chung SJ, Min JK. Ginkgetin, a biflavone from Ginkgo biloba leaves, prevents adipogenesis through STAT5-mediated PPARγ and C/EBPα regulation. Pharmacol Res 2019; 139:325-336. [DOI: 10.1016/j.phrs.2018.11.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 09/28/2018] [Accepted: 11/20/2018] [Indexed: 12/13/2022]
|
7
|
Jia D, Zheng W, Jiang H. Growth hormone facilitates 5'-azacytidine-induced myogenic but inhibits 5'-azacytidine-induced adipogenic commitment in C3H10T1/2 mesenchymal stem cells. Growth Horm IGF Res 2018; 40:9-16. [PMID: 29626795 DOI: 10.1016/j.ghir.2018.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/19/2018] [Accepted: 03/27/2018] [Indexed: 11/20/2022]
Abstract
The C3H10T1/2 cells are considered mesenchymal stem cells (MSCs) because they can be induced to become the progenitor cells for myocytes, adipocytes, osteoblasts, and chondrocytes by the DNA methyltransferase inhibitor 5'-azacytidine. In this study, we determined the effect of growth hormone (GH) on the myogenic and adipogenic lineage commitment in C3H10T1/2 cells. The C3H10T1/2 cells were treated with recombinant bovine GH in the presence or absence of 5'-azacytidine for 4 days. The myogenic commitment in C3H10T1/2 cells was assessed by immunostaining them for MyoD, the marker for myoblasts, and by determining their capacity to differentiate into the multinucleated myotubes. The adipogenic commitment in C3H10T1/2 cells was assessed by determining their ability to differentiate into adipocytes. Myotubes and adipocyteswere identified by immunocytochemistry and Oil Red O staining, respectively. C3H10T1/2 cells treated with 5'-azacytidine and GH for 4 days contained a greater percentage of MyoD-positive cells than those treated with 5'-axacytidine alone (P < 0.05). The former generated more myotubes than the latter upon induced myoblast differentiation (P < 0.05). However, C3H10T1/2 cells treated with GH alone did not form any myotubes. C3H10T1/2 cells treated with 5'-azacytidine formed adipocytes upon adipocyte differentiation induction, whereas C3H10T1/2 cells treated with GH alone did not form any adipocytes. C3H10T1/2 cells treated with both 5'-azacytidine and GH formed fewer adipocytes than those treated with 5'-azacytidine alone (P < 0.05). Both GHR and IGF-I mRNA expression in C3H10T1/2 cells were increased by 5'-azacytidine (P < 0.05), but neither was affected by GH. Overall, this study showed that GH enhanced 5'-azacytidine-induced commitment in C3H10T1/2 cells to myoblasts but inhibited 5'-azacytidine-induced commitment to preadipocytes. These results support the possibility that GH stimulates skeletal muscle growth and inhibits adipose tissue growth in part by stimulating the myogenic commitment and inhibiting the adipogenic commitment, respectively, in mesenchymal stem cells.
Collapse
Affiliation(s)
- Dan Jia
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Weijiang Zheng
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, United States; College of Animal Sciences, Nanjing Agricultural University, Nanjing, China
| | - Honglin Jiang
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, United States.
| |
Collapse
|
8
|
|
9
|
Mitchell M, Strick R, Strissel PL, Dittrich R, McPherson NO, Lane M, Pliushch G, Potabattula R, Haaf T, El Hajj N. Gene expression and epigenetic aberrations in F1-placentas fathered by obese males. Mol Reprod Dev 2017; 84:316-328. [PMID: 28186371 DOI: 10.1002/mrd.22784] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/06/2017] [Indexed: 12/17/2022]
Abstract
Gene expression and/or epigenetic deregulation may have consequences for sperm and blastocysts, as well as for the placenta, together potentially contributing to problems observed in offspring. We previously demonstrated specific perturbations of fertilization, blastocyst formation, implantation, as well as aberrant glucose metabolism and adiposity in offspring using a mouse model of paternal obesity. The current investigation analyzed gene expression and methylation of specific CpG residues in F1 placentas of pregnancies fathered by obese and normal-weight male mice, using real-time PCR and bisulfite pyrosequencing. Our aim was to determine if paternal obesity deregulated placental gene expression and DNA methylation when compared to normal-weight males. Gene methylation of sperm DNA was analyzed and compared to placentas to address epigenetic transmission. Of the 10 paternally expressed genes (Pegs), 11 genes important for development and transport of nutrients, and the long-terminal repeat Intracisternal A particle (IAP) elements, derived from a member of the class II endogenous retroviral gene family, we observed a significant effect of paternal diet-induced obesity on deregulated expression of Peg3, Peg9, Peg10, and the nutrient transporter gene Slc38a2, and aberrant DNA methylation of the Peg9 promoter in F1 placental tissue. Epigenetic changes in Peg9 were also found in sperm from obese fathers. We therefore propose that paternal obesity renders changes in gene expression and/or methylation throughout the placental genome, which could contribute to the reproductive problems related to fertility and to the metabolic, long-term health impact on offspring.
Collapse
Affiliation(s)
- Megan Mitchell
- Department of Obstetrics and Gynaecology, Erlangen University Hospital, Laboratory for Molecular Medicine, Universitaetsstrasse, Erlangen, Germany.,School of Paediatrics and Reproductive Health, The Robinson Institute, University of Adelaide, South Australia, Australia
| | - Reiner Strick
- Department of Obstetrics and Gynaecology, Erlangen University Hospital, Laboratory for Molecular Medicine, Universitaetsstrasse, Erlangen, Germany
| | - Pamela L Strissel
- Department of Obstetrics and Gynaecology, Erlangen University Hospital, Laboratory for Molecular Medicine, Universitaetsstrasse, Erlangen, Germany
| | - Ralf Dittrich
- Department of Obstetrics and Gynaecology, Erlangen University Hospital, Laboratory for Molecular Medicine, Universitaetsstrasse, Erlangen, Germany
| | - Nicole O McPherson
- School of Paediatrics and Reproductive Health, The Robinson Institute, University of Adelaide, South Australia, Australia
| | - Michelle Lane
- School of Paediatrics and Reproductive Health, The Robinson Institute, University of Adelaide, South Australia, Australia.,Repromed, Dulwich, Adelaide, South Australia
| | - Galyna Pliushch
- Institute of Human Genetics, Julius Maximillians University, Biozentrum, Am Hubland, Würzburg, Germany
| | - Ramya Potabattula
- Institute of Human Genetics, Julius Maximillians University, Biozentrum, Am Hubland, Würzburg, Germany
| | - Thomas Haaf
- Institute of Human Genetics, Julius Maximillians University, Biozentrum, Am Hubland, Würzburg, Germany
| | - Nady El Hajj
- Institute of Human Genetics, Julius Maximillians University, Biozentrum, Am Hubland, Würzburg, Germany
| |
Collapse
|
10
|
Olarescu NC, Berryman DE, Householder LA, Lubbers ER, List EO, Benencia F, Kopchick JJ, Bollerslev J. GH action influences adipogenesis of mouse adipose tissue-derived mesenchymal stem cells. J Endocrinol 2015; 226:13-23. [PMID: 25943560 PMCID: PMC4560118 DOI: 10.1530/joe-15-0012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/05/2015] [Indexed: 12/15/2022]
Abstract
GH influences adipocyte differentiation, but both stimulatory and inhibitory effects have been described. Adipose tissue-derived mesenchymal stem cells (AT-MSCs) are multipotent and are able to differentiate into adipocytes, among other cells. Canonical Wnt/β-catenin signaling activation impairs adipogenesis. The aim of the present study was to elucidate the role of GH on AT-MSC adipogenesis using cells isolated from male GH receptor knockout (GHRKO), bovine GH transgenic (bGH) mice, and wild-type littermate control (WT) mice. AT-MSCs from subcutaneous (sc), epididiymal (epi), and mesenteric (mes) AT depots were identified and isolated by flow cytometry (Pdgfrα+ Sca1+ Cd45- Ter119- cells). Their in vitro adipogenic differentiation capacity was determined by cell morphology and real-time RT-PCR. Using identical in vitro conditions, adipogenic differentiation of AT-MSCs was only achieved in the sc depot, and not in epi and mes depots. Notably, we observed an increased differentiation in cells isolated from sc-GHRKO and an impaired differentiation of sc-bGH cells as compared to sc-WT cells. Axin2, a marker of Wnt/β-catenin activation, was increased in mature sc-bGH adipocytes, which suggests that activation of this pathway may be responsible for the decreased adipogenesis. Thus, the present study demonstrates that (i) adipose tissue in mice has a well-defined population of Pdgfrα+ Sca1+ MSCs; (ii) the differentiation capacity of AT-MSCs varies from depot to depot regardless of GH genotype; (iii) the lack of GH action increases adipogenesis in the sc depot; and iv) activation of the Wnt/β-catenin pathway might mediate the GH effect on AT-MSCs. Taken together, the present results suggest that GH diminishes fat mass in part by altering adipogenesis of MSCs.
Collapse
Affiliation(s)
- Nicoleta C Olarescu
- Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA
| | - Darlene E Berryman
- Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA
| | - Lara A Householder
- Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA
| | - Ellen R Lubbers
- Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA
| | - Edward O List
- Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA
| | - Fabian Benencia
- Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA
| | - John J Kopchick
- Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA
| | - Jens Bollerslev
- Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA Section of Specialized EndocrinologyDepartment of Endocrinology, Oslo University Hospital, Rikshospitalet, PO Box 4950, N-0424 Oslo, NorwayFaculty of MedicineUniversity of Oslo, Oslo, NorwayEdison Biotechnology InstituteOhio University, Athens, Ohio, USAHeritage College of Osteopathic MedicineOhio University, Athens, Ohio, USA
| |
Collapse
|
11
|
Veenvliet JV, Smidt MP. Molecular mechanisms of dopaminergic subset specification: fundamental aspects and clinical perspectives. Cell Mol Life Sci 2014; 71:4703-27. [PMID: 25064061 PMCID: PMC11113784 DOI: 10.1007/s00018-014-1681-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/04/2014] [Accepted: 07/10/2014] [Indexed: 12/22/2022]
Abstract
Dopaminergic (DA) neurons in the ventral mesodiencephalon control locomotion and emotion and are affected in psychiatric and neurodegenerative diseases, such as Parkinson's disease (PD). A clinical hallmark of PD is the specific degeneration of DA neurons located within the substantia nigra (SNc), whereas neurons in the ventral tegmental area remain unaffected. Recent advances have highlighted that the selective vulnerability of the SNc may originate in subset-specific molecular programming during DA neuron development, and significantly increased our understanding of the molecular code that drives specific SNc development. We here present an up-to-date overview of molecular mechanisms that direct DA subset specification, integrating our current knowledge about subset-specific roles of transcription factors, signaling pathways and morphogenes. We discuss strategies to further unravel subset-specific gene-regulatory networks, and the clinical promise of fundamental knowledge about subset specification of DA neurons, with regards to cell replacement therapy and cell-type-specific vulnerability in PD.
Collapse
Affiliation(s)
- Jesse V. Veenvliet
- Department of Molecular Neuroscience, Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Marten P. Smidt
- Department of Molecular Neuroscience, Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| |
Collapse
|
12
|
Adipose stromal-vascular fraction-derived paracrine factors regulate adipogenesis. Mol Cell Biochem 2014; 385:115-23. [PMID: 24122418 DOI: 10.1007/s11010-013-1820-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 09/13/2013] [Indexed: 10/26/2022]
Abstract
Visceral and subcutaneous adipose tissue depots have distinct features and contribute differentially to metabolic disease. Therefore, the adipogenic potential of different fat depots was investigated and found to be higher in subcutaneous compared with visceral stromal-vascular fraction (SVF), which contains adipocyte precursor cells. This increased differentiation capacity was not due to elevated numbers of Lin-Sca1+CD29+CD34+Pref1+ precursor cells, as the number of preadipocytes was higher in visceral than in subcutaneous SVF. The secreted heat-sensitive factors from the SVF inhibited adipocyte differentiation more in visceral than in subcutaneous SVF. In order to explore secreted proteins that potentially inhibit differentiation, the secretome of murine SVF was analyzed by mass spectrometry, which resulted in the identification of 113 secreted proteins with an overlap of 42 % between subcutaneous and visceral SVF. Comparison of the mRNA expression in SVF from both depots revealed 16 transcripts that were significantly expressed more in visceral than in subcutaneous SVF. A functional differentiation screen identified seven potential inhibitory candidates: biglycan, decorin, bone morphogenic protein 1, epidermal growth factor-containing fibulin-like extracellular matrix protein 2, elastin microfibril interfacer 1, matrix gla protein, and Sparc-like 1. For further verification, murine recombinant decorin or Sparc-like 1 was added to the media during the differentiation process leading to a dose-dependent decrease in adipogenesis. Further analysis will be necessary to assess the impact of the other candidates on adipocyte differentiation.
Collapse
|
13
|
Arellanes-Licea EDC, Báez-Ruiz A, Carranza ME, Arámburo C, Luna M, Díaz-Muñoz M. Daily patterns and adaptation of the ghrelin, growth hormone and insulin-like growth factor-1 system under daytime food synchronisation in rats. J Neuroendocrinol 2014; 26:282-95. [PMID: 24617825 DOI: 10.1111/jne.12145] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Revised: 02/07/2014] [Accepted: 03/06/2014] [Indexed: 11/29/2022]
Abstract
Daytime restricted feeding promotes the re-alignment of the food entrained oscillator (FEO). Endocrine cues which secretion is regulated by the transition of fasting and feeding cycles converge in the FEO. The present study aimed to investigate the ghrelin, growth hormone (GH) and insulin-like growth factor (IGF)-1 system because their release depends on rhythmic and nutritional factors, and the output from the system influences feeding and biochemical status. In a daily sampling approach, rats that were fed ad lib. were compared with rats on a reversed (daytime) and restricted feeding schedule by 3 weeks (dRF; food access for 2 h), also assessing the effect of acute fasting and refeeding. We undertook measurements of clock protein BMAL1 and performed somatometry of peripheral organs and determined the concentration of total, acylated and unacylated ghrelin, GH and IGF-1 in both serum and in its main synthesising organs. During dRF, BMAL1 expression was synchronised to mealtime in hypophysis and liver; rats exhibited acute hyperphagia, stomach distension with a slow emptying, a phase shift in liver mass towards the dark period and decrease in mass perigonadal white adipose tissue. Total ghrelin secretion during the 24-h period increased in the dRF group as a result of elevation of the unacylated form. By contrast, GH and IGF-1 serum concentration fell, with a modification of GH daily pattern after mealtime. In the dRF group, ghrelin content in the stomach and pituitary GH content decreased, whereas hepatic IGF-1 remained equal. The daily patterns and synthesis of these hormones had a rheostatic adaptation. The endocrine adaptive response elicited suggests that it may be associated with the regulation of metabolic, behavioural and physiological processes during the paradigm of daytime restricted feeding and associated FEO activity.
Collapse
Affiliation(s)
- E del C Arellanes-Licea
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | | | | | | | | | | |
Collapse
|
14
|
Zhao L, Wang A, Corl BA, Jiang H. Effect of growth hormone on the differentiation of bovine preadipocytes into adipocytes and the role of the signal transducer and activator of transcription 5b. J Anim Sci 2014; 92:1958-67. [PMID: 24668956 DOI: 10.2527/jas.2013-7113] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We evaluated the effect of GH on the differentiation of primary bovine preadipocytes into adipocytes. Bovine preadipocytes, derived from adipose tissue explants, were induced to differentiate into adipocytes in the presence or absence of recombinant bovine GH. The differentiation status of adipocytes was assessed by Oil Red O staining and by measuring the activity of glycerol-3-phosphate dehydrogenase (G3PDH) and the rate of acetate incorporation. Fewer preadipocytes became adipocytes in the presence of GH than in the absence of GH; adipocytes formed in the presence of GH had lower G3PDH activity and lower rate of acetate incorporation than those formed without GH treatment (P < 0.05). These data suggest an inhibitory effect of GH on the differentiation of bovine preadipocytes into adipocytes. Growth hormone decreased the expression of C/EBPα and PPARγ mRNA in bovine adipocytes (P < 0.05). Because C/EBPα and PPARγ are the master regulators of adipocyte differentiation, this data suggests that GH might inhibit the differentiation of bovine preadipocytes into adipocytes by inhibiting the expression of C/EBPα and/or PPARγ. Because the signal transducer and activator of transcription 5 (STAT5) is a major component of signaling from the GH receptor, we next determined the potential role of STAT5 in GH inhibition of bovine adipocyte differentiation. Overexpression of a constitutively active form of STAT5b (STAT5bCA) in bovine preadipocytes through adenoviral transduction mimicked the effects of GH on the formation of lipid-containing adipocytes, G3PDH activity, and acetate incorporation rate. Overexpression of STAT5bCA was associated with decreased expression of C/EBPα mRNA (P < 0.05) but not that of PPARγ mRNA in bovine adipocytes. These results support a role of STAT5b in mediating GH inhibition of C/EBPα expression but not that of PPARγ expression in bovine preadipocytes. Overall, the present study suggests that GH may inhibit adipose growth in cattle in part by inhibiting adipogenesis and that GH inhibits the differentiation of bovine preadipocytes to adipocytes through STAT5b-dependent inhibition of C/EBPα expression and STAT5b-independent inhibition of PPARγ expression.
Collapse
Affiliation(s)
- L Zhao
- Department of Animal and Poultry Sciences
| | | | | | | |
Collapse
|
15
|
Sun L, Trajkovski M. MiR-27 orchestrates the transcriptional regulation of brown adipogenesis. Metabolism 2014; 63:272-82. [PMID: 24238035 DOI: 10.1016/j.metabol.2013.10.004] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/02/2013] [Accepted: 10/16/2013] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Brown adipose tissue (BAT) produces heat using chemical energy of lipids and glucose, a function induced by cold exposure or diet. The brown adipogenesis is tightly controlled in a coordinated interplay between several transcriptional factors. It is not known what enables and coordinates this robust program of concerted cooperation between the transcriptional factors and co-regulators necessary for the brown adipogenesis. MATERIALS/METHODS A. In vivo studies--we investigated the expression levels of miR-27a and b in mice after cold exposure. B. Using gene expression and functional studies together with high throughput imaging in primary preadipocytes, and cell culture models, we investigated the role of miR-27 in beige and brown adipogenesis. C. Using gene silencing and rescue experiments we dissected the molecular mechanisms of the miR-27 action. RESULTS After cold exposure, miR-27 is downregulated in BAT and subcutaneous white adipose tissue (SAT). MiR-27 is also downregulated during brown adipogenesis of primary preadipocytes in vitro, and it directly targets and negatively regulates the essential components of the brown transcriptional network: Prdm16, Pparα, Creb, and in part Pgc1β. Together with its direct effect on Pparγ, and indirect on Pgc1α, mir-27 decreases brown differentiation of cultured cells and of primary SAT preadipocytes. CONCLUSIONS Our results point to miR-27 as a central upstream regulator of the transcriptional network involved in beige and brown adipogenesis after cold exposure, and suggest miR-27 inhibition as a novel therapeutic approach for metabolic diseases aiming at increasing the beige/brown fat mass.
Collapse
Affiliation(s)
- Lei Sun
- Duke-NUS Medical School Singapore, 8 College Rd, 169857, Singapore; Institute of Molecular and Cell Biology (IMCB), Agency for Science,Technology and Research, 61 Biopolis Drive, 138673, Singapore
| | - Mirko Trajkovski
- University of Geneva, Medical Faculty, Department of Cell Physiology and Metabolism, Centre Médical Universitaire (CMU), 1211 Geneva 4, Switzerland; University College London (UCL), Division of Biosciences, School of Life and Medical Sciences, Institute of Structural and Molecular Biology, Darwin Building, Gower Street, WC1E 6BT, London, UK.
| |
Collapse
|
16
|
MyomiR-133 regulates brown fat differentiation through Prdm16. Nat Cell Biol 2013; 14:1330-5. [PMID: 23143398 DOI: 10.1038/ncb2612] [Citation(s) in RCA: 208] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 10/03/2012] [Indexed: 01/16/2023]
Abstract
Brown adipose tissue (BAT) uses the chemical energy of lipids and glucose to produce heat, a function that can be induced by cold exposure or diet. A key regulator of BAT is the gene encoding PR domain containing 16 (Prdm16), whose expression can drive differentiation of myogenic and white fat precursors to brown adipocytes. Here we show that after cold exposure, the muscle-enriched miRNA-133 is markedly downregulated in BAT and subcutaneous white adipose tissue (SAT) as a result of decreased expression of its transcriptional regulator Mef2. miR-133 directly targets and negatively regulates PRDM16, and inhibition of miR-133 or Mef2 promotes differentiation of precursors from BAT and SAT to mature brown adipocytes, thereby leading to increased mitochondrial activity. Forced expression of miR-133 in brown adipogenic conditions prevents the differentiation to brown adipocytes in both BAT and SAT precursors. Our results point to Mef2 and miR-133 as central upstream regulators of Prdm16 and hence of brown adipogenesis in response to cold exposure in BAT and SAT.
Collapse
|
17
|
Abstract
Preadipocyte factor 1 (Pref-1, also called Dlk1/FA1) is a molecular gatekeeper of adipogenesis which acts by maintaining the preadipocyte state and preventing adipocyte differentiation. Pref-1 is made as an epidermal growth factor-like repeat containing transmembrane protein, and is cleaved by TNFα-converting enzyme (TACE) to generate a soluble form, which acts as an autocrine/paracrine factor. Pref-1 upregulates Sox9 expression by activating the ERK/MAPK pathway and the Pref-1 interaction with fibronectin is required for inhibition of adipogenesis. Pref-1 also prevents brown adipocyte differentiation and its thermogenic function. Here, we highlight the recent evidence for the role of Pref-1 in adipogenesis.
Collapse
Affiliation(s)
- Carolyn S. Hudak
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
| | - Hei Sook Sul
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, USA
- *Correspondence: Hei Sook Sul, Department of Nutritional Sciences and Toxicology, University of California, 219 Morgan Hall, Berkeley, CA 94720, USA e-mail:
| |
Collapse
|
18
|
Appelbe OK, Yevtodiyenko A, Muniz-Talavera H, Schmidt JV. Conditional deletions refine the embryonic requirement for Dlk1. Mech Dev 2012; 130:143-59. [PMID: 23059197 DOI: 10.1016/j.mod.2012.09.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 09/13/2012] [Accepted: 09/28/2012] [Indexed: 12/21/2022]
Abstract
Numerous studies have implicated Delta-like 1 (DLK1), a transmembrane protein that shares homology with Notch ligands, in embryonic growth and differentiation. Dlk1 expression is widespread, though not ubiquitous, during early development, but is confined to a few specific cell types in adults. Adult Dlk1-expressing tissues include the Insulin-producing β-cells of the pancreas and the Growth hormone-producing somatotrophs of the pituitary gland. Previously generated Dlk1 null mice (Dlk1(Sul-pat)), display a partially penetrant neonatal lethality and a complex pattern of developmental and adult phenotypes. Here we describe the generation of a conditional Dlk1 mouse line (Dlk1(flox)) to facilitate cell type-specific deletion of the Dlk1 gene, providing a powerful system to explore each aspect of the Dlk1 null phenotype. Four tissue-specific Cre mouse lines were used to produce individual Dlk1 deletions in pancreatic β-cells, pituitary somatotrophs and the endothelial cells of the embryo and placenta, key candidates for the Dlk1 phenotype. Contrary to expectations, all of these conditional mice were fully viable, and none recapitulated any aspect of the Dlk1(Sul-pat) null mice. Dlk1 expression is therefore not essential for the normal development of β-cells, somatotrophs and endothelial cells, and the tissues responsible for the Dlk1 null phenotype remain to be identified. Dlk1(flox) mice will continue to provide an important tool for further research into the function of Dlk1.
Collapse
Affiliation(s)
- Oliver K Appelbe
- Department of Biological Sciences, University of Illinois at Chicago, 900 S. Ashland Avenue, Chicago, IL 60607, USA.
| | | | | | | |
Collapse
|
19
|
Taipaleenmäki H, Harkness L, Chen L, Larsen KH, Säämänen AM, Kassem M, Abdallah BM. The crosstalk between transforming growth factor-β1 and delta like-1 mediates early chondrogenesis during embryonic endochondral ossification. Stem Cells 2012; 30:304-13. [PMID: 22102178 DOI: 10.1002/stem.792] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Delta like-1 (Dlk1)/preadipocyte factor-1 (Pref-1)/fetal antigen-1 (FA1) is a novel surface marker for embryonic chondroprogenitor cells undergoing lineage progression from proliferation to prehypertrophic stages. However, mechanisms mediating control of its expression during chondrogenesis are not known. Thus, we examined the effect of a number of signaling molecules and their inhibitors on Dlk1 expression during in vitro chondrogenic differentiation in mouse embryonic limb bud mesenchymal micromass cultures and mouse embryonic fibroblast (MEF) pellet cultures. Dlk1/Pref-1 was initially expressed during mesenchymal condensation and chondrocyte proliferation, in parallel with expression of Sox9 and Col2a1, and was downregulated upon the expression of Col10a1 by hypertrophic chondrocytes. Among a number of molecules that affected chondrogenesis, transforming growth factor-β1 (TGF-β1)-induced proliferation of chondroprogenitors was associated with decreased Dlk1 expression. This effect was abolished by TGF-β signaling inhibitor SB431542, suggesting regulation of Dlk1/FA1 by TGF-β1 signaling in chondrogenesis. TGF-β1-induced Smad phosphorylation and chondrogenesis were significantly increased in Dlk1(-/-) MEF, while they were blocked in Dlk1 overexpressing MEF, in comparison with wild-type MEF. Furthermore, overexpression of Dlk1 or addition of its secreted form FA1 dramatically inhibited TGF-β1-induced Smad reporter activity. In conclusion, our data identified Dlk1/FA1 as a downstream target of TGF-β1 signaling molecule that mediates its function in embryonic chondrogenesis. The crosstalk between TGF-β1 and Dlk1/FA1 was shown to promote early chondrogenesis during the embryonic endochondral ossification process.
Collapse
Affiliation(s)
- Hanna Taipaleenmäki
- Endocrine Research Laboratory (KMEB), Department of Endocrinology and Metabolism, Odense University Hospital, Odense, Denmark
| | | | | | | | | | | | | |
Collapse
|
20
|
Jacobs FMJ, Veenvliet JV, Almirza WH, Hoekstra EJ, von Oerthel L, van der Linden AJA, Neijts R, Koerkamp MG, van Leenen D, Holstege FCP, Burbach JPH, Smidt MP. Retinoic acid-dependent and -independent gene-regulatory pathways of Pitx3 in meso-diencephalic dopaminergic neurons. Development 2012; 138:5213-22. [PMID: 22069189 DOI: 10.1242/dev.071704] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Development of meso-diencephalic dopamine (mdDA) neurons requires the combined actions of the orphan nuclear receptor Nurr1 and the paired-like homeobox transcription factor Pitx3. Whereas all mdDA neurons require Nurr1 for expression of Th and survival, dependence on Pitx3 is displayed only by the mdDA subpopulation that will form the substantia nigra (SNc). Previously, we have demonstrated that Pitx3(-/-) embryos lack the expression of the retinoic acid (RA)-generating enzyme Ahd2, which is normally selectively expressed in the Pitx3-dependent DA neurons of the SNc. Restoring RA signaling in Pitx3(-/-) embryos revealed a selective dependence of SNc neurons on the presence of RA for differentiation into Th-positive neurons and maintenance throughout embryonic development. Whereas these data are suggestive of an important developmental role for RA in neurons of the SNc, it remained unclear whether other Nurr1 and Pitx3 target genes depend on RA signaling in a manner similar to Th. In the search for genes that were affected in Pitx3-deficient mdDA neurons and restored upon embryonic RA treatment, we provide evidence that Delta-like 1, D2R (Drd2) and Th are regulated by Pitx3 and RA signaling, which influences the mdDA terminal differentiated phenotype. Furthermore, we show that regulation of Ahd2-mediated RA signaling represents only one aspect of the Pitx3 downstream cascade, as Vmat2, Dat, Ahd2 (Aldh1a1), En1, En2 and Cck were unaffected by RA treatment and are (subset) specifically modulated by Pitx3. In conclusion, our data reveal several RA-dependent and -independent aspects of the Pitx3-regulated gene cascade, suggesting that Pitx3 acts on multiple levels in the molecular subset-specification of mdDA neurons.
Collapse
Affiliation(s)
- Frank M J Jacobs
- Rudolf Magnus Institute, Department of Neuroscience and Pharmacology, UMC Utrecht, Utrecht, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Meissburger B, Ukropec J, Roeder E, Beaton N, Geiger M, Teupser D, Civan B, Langhans W, Nawroth PP, Gasperikova D, Rudofsky G, Wolfrum C. Adipogenesis and insulin sensitivity in obesity are regulated by retinoid-related orphan receptor gamma. EMBO Mol Med 2011; 3:637-51. [PMID: 21853531 PMCID: PMC3377107 DOI: 10.1002/emmm.201100172] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Revised: 07/07/2011] [Accepted: 07/21/2011] [Indexed: 01/23/2023] Open
Abstract
Obesity is a well-known risk factor for the development of secondary complications such as type 2 diabetes. However, only a part of the obese population develops secondary metabolic disorders. Here, we identify the transcription factor retinoid-related orphan receptor gamma (RORγ) as a negative regulator of adipocyte differentiation through expression of its newly identified target gene matrix metalloproteinase 3. In vivo differentiation of adipocyte progenitor cells from Rorγ-deficient mice is enhanced and obese Rorγ−/− mice show decreased adipocyte sizes. These small adipocytes are highly insulin sensitive, leading to an improved control of circulating free fatty acids. Ultimately, Rorγ−/− mice are protected from hyperglycemia and insulin resistance in the state of obesity. In adipose stromal-vascular fraction from obese human subjects, Rorγ expression is correlated with adipocyte size and negatively correlated with adipogenesis and insulin sensitivity. Taken together, our findings identify RORγ as a factor, which controls adipogenesis as well as adipocyte size and modulates insulin sensitivity in obesity. RORγ might therefore serve as a novel pharmaceutical target to treat obesity-associated insulin resistance.
Collapse
Affiliation(s)
- Bettina Meissburger
- ETH Zürich, Institute of Food Nutrition and Health, Schwerzenbach, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
MicroRNAs 103 and 107 regulate insulin sensitivity. Nature 2011; 474:649-53. [PMID: 21654750 DOI: 10.1038/nature10112] [Citation(s) in RCA: 759] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 04/13/2011] [Indexed: 12/15/2022]
Abstract
Defects in insulin signalling are among the most common and earliest defects that predispose an individual to the development of type 2 diabetes. MicroRNAs have been identified as a new class of regulatory molecules that influence many biological functions, including metabolism. However, the direct regulation of insulin sensitivity by microRNAs in vivo has not been demonstrated. Here we show that the expression of microRNAs 103 and 107 (miR-103/107) is upregulated in obese mice. Silencing of miR-103/107 leads to improved glucose homeostasis and insulin sensitivity. In contrast, gain of miR-103/107 function in either liver or fat is sufficient to induce impaired glucose homeostasis. We identify caveolin-1, a critical regulator of the insulin receptor, as a direct target gene of miR-103/107. We demonstrate that caveolin-1 is upregulated upon miR-103/107 inactivation in adipocytes and that this is concomitant with stabilization of the insulin receptor, enhanced insulin signalling, decreased adipocyte size and enhanced insulin-stimulated glucose uptake. These findings demonstrate the central importance of miR-103/107 to insulin sensitivity and identify a new target for the treatment of type 2 diabetes and obesity.
Collapse
|
23
|
Trajkovski M, Hausser J, Soutschek J, Bhat B, Akin A, Zavolan M, Heim MH, Stoffel M. MicroRNAs 103 and 107 regulate insulin sensitivity. Nature 2011. [PMID: 21654750 DOI: 10.1038/nature10112;] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Defects in insulin signalling are among the most common and earliest defects that predispose an individual to the development of type 2 diabetes. MicroRNAs have been identified as a new class of regulatory molecules that influence many biological functions, including metabolism. However, the direct regulation of insulin sensitivity by microRNAs in vivo has not been demonstrated. Here we show that the expression of microRNAs 103 and 107 (miR-103/107) is upregulated in obese mice. Silencing of miR-103/107 leads to improved glucose homeostasis and insulin sensitivity. In contrast, gain of miR-103/107 function in either liver or fat is sufficient to induce impaired glucose homeostasis. We identify caveolin-1, a critical regulator of the insulin receptor, as a direct target gene of miR-103/107. We demonstrate that caveolin-1 is upregulated upon miR-103/107 inactivation in adipocytes and that this is concomitant with stabilization of the insulin receptor, enhanced insulin signalling, decreased adipocyte size and enhanced insulin-stimulated glucose uptake. These findings demonstrate the central importance of miR-103/107 to insulin sensitivity and identify a new target for the treatment of type 2 diabetes and obesity.
Collapse
Affiliation(s)
- Mirko Trajkovski
- Institute for Molecular Systems Biology, ETH Zurich, Wolfgang-Pauli Strasse 16, CH-8093 Zurich, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Meissburger B, Stachorski L, Röder E, Rudofsky G, Wolfrum C. Tissue inhibitor of matrix metalloproteinase 1 (TIMP1) controls adipogenesis in obesity in mice and in humans. Diabetologia 2011; 54:1468-79. [PMID: 21437772 DOI: 10.1007/s00125-011-2093-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 01/20/2011] [Indexed: 11/29/2022]
Abstract
AIMS/HYPOTHESIS Extracellular matrix reorganisation is a crucial step of adipocyte differentiation and is controlled by the matrix metalloproteinase-tissue inhibitor of matrix metalloproteinase (TIMP) enzyme system. We therefore sought to define the role of TIMP1 in adipogenesis and to elucidate whether upregulation of TIMP1 in obesity has direct effects on adipocyte formation. METHODS TIMP1 protein levels and mRNA were measured in lean and obese mice with a focus on levels in adipose tissue. We also analysed the effect of recombinant murine TIMP1 on adipogenesis, adipocyte size and metabolic control in vitro and in vivo. RESULTS TIMP1 levels were increased in the serum and adipose tissue of obese mouse models. Recombinant murine TIMP1 inhibited adipocyte differentiation in 3T3-L1 as well as in subcutaneous primary pre-adipocytes. Conversely, neutralising TIMP1 with a specific antibody enhanced adipocyte differentiation. In vivo, injection of recombinant TIMP1 in mice challenged with a high-fat diet led to enlarged adipocytes. TIMP1-treated mice developed an impaired metabolic profile with increased circulating NEFA levels, hepatic triacylglycerol accumulation and accelerated insulin resistance. Altered glucose clearance in TIMP1-injected mice was due to changes in adipose tissue glucose uptake, whereas muscle glucose clearance remained unaffected. CONCLUSIONS/INTERPRETATION TIMP1 is a negative regulator of adipogenesis. In vivo, TIMP1 leads to enlarged adipocytes in the state of overnutrition. This might contribute to the detrimental metabolic consequences seen in TIMP1-injected mice, such as systemic fatty acid overload, hepatic lipid accumulation and insulin resistance.
Collapse
Affiliation(s)
- B Meissburger
- Swiss Federal Institute of Technology, ETH Zürich, Institute for ETH Zürich, Food Nutrition and Health, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
| | | | | | | | | |
Collapse
|
25
|
Glad CAM, Kitchen EEJ, Russ GC, Harris SM, Davies JS, Gevers EF, Gabrielsson BG, Wells T. Reverse feeding suppresses the activity of the GH axis in rats and induces a preobesogenic state. Endocrinology 2011; 152:869-82. [PMID: 21209022 DOI: 10.1210/en.2010-0713] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Reversed feeding (RF) is known to disrupt hormone rhythmicity and metabolism. Although these effects may be mediated in part by phase inversion of glucocorticoid secretion, the precise mechanism is incompletely characterized. In this study, we demonstrate that acute nocturnal food deprivation in male rats suppressed the amplitude of spontaneous GH secretion during the dark phase by 62% (P < 0.001), without affecting baseline secretion. Prolonged RF, which reduced pituitary weight (by 22%; P < 0.05), also suppressed GH pulse height sufficiently to reduce skeletal growth (by 4-5%; P < 0.01) and terminal liver weight (by 11%; P < 0.001). Despite this suppression of the GH axis, proportionate adiposity was not elevated, probably due to the accompanying 16% reduction in cumulative food intake (P < 0.01). We demonstrate that RF also resulted in phase inversion of core clock gene expression in liver, abdominal white adipose tissue (WAT) and skeletal muscle, without affecting their expression patterns in the suprachiasmatic nucleus. In addition, RF resulted in phase inversion of hepatic peroxisome proliferator-activated receptor γ2 mRNA expression, a 3- to 5-fold elevation in fatty acid synthase mRNA in WAT in both light- and dark-phase samples (P < 0.01) and an elevation in muscle uncoupling protein 3 mRNA expression at the beginning of the light phase (P < 0.01). Consumption of a high-fat diet increased inguinal (by 36%; P < 0.05) and retroperitoneal WAT weight (by 72%; P < 0.01) only in RF-maintained rats, doubling the efficiency of lipid accumulation (P < 0.05). Thus, RF not only desynchronizes central and peripheral circadian clocks, and suppresses nocturnal GH secretion, but induces a preobesogenic state.
Collapse
Affiliation(s)
- Camilla A-M Glad
- Department of Endocrinology, Institute of Medicine, The Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Göteborg, Sweden
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Poulos SP, Dodson MV, Hausman GJ. Cell line models for differentiation: preadipocytes and adipocytes. Exp Biol Med (Maywood) 2010; 235:1185-93. [PMID: 20864461 DOI: 10.1258/ebm.2010.010063] [Citation(s) in RCA: 207] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In vitro models have been invaluable in determining the mechanisms involved in adipocyte proliferation, differentiation, adipokine secretion and gene/protein expression. The cells presently available for research purposes all have unique advantages and disadvantages that one should be aware of when selecting cells. Established cell lines, such as 3T3-L1 cells, are easier and less costly to use than freshly isolated cells, even though freshly isolated cells allow for various comparisons such as the in vitro evaluation of different in vivo conditions that may not be possible using cell lines. Moreover, stem cells, transdifferentiated cells or dedifferentiated cells are relatively new cell models being evaluated for the study of adipocyte regulation and physiology. The focus of this brief review is to highlight similarities and differences in adipocyte models to aid in appropriate model selection and data interpretation for successful advancement of our understanding of adipocyte biology.
Collapse
Affiliation(s)
- Sylvia P Poulos
- The Coca-Cola Company, Research and Technology, Atlanta, GA 30313, USA.
| | | | | |
Collapse
|
27
|
Nakatani H, Aoki N, Okajima T, Nadano D, Flint D, Matsuda T. Establishment of a mammary stromal fibroblastic cell line for in vitro studies in mice of mammary adipocyte differentiation. Biol Reprod 2010; 82:44-53. [PMID: 19684333 DOI: 10.1095/biolreprod.109.077958] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024] Open
Abstract
Mammary stromal adipose tissue remodeling is important for appropriate mammary gland development during pregnancy, lactation, and involution. However, the precise mechanisms underlying mammary stromal adipose tissue remodeling remain unclear. We have established a mammary stromal, fibroblastlike cell line (MSF) from primary mouse mammary culture by introducing a temperature-sensitive simian virus-40 large tumor antigen. Among several hormones related to mammary gland development, hydrocortisone was found to commit MSF cells to a preadipocyte lineage, whereas insulin was found to induce extracellular matrix-dependent adipogenic differentiation of the cells, as assessed by lipid accumulation and marker gene expression. Interestingly, such hormone-induced adipogenic differentiation of MSF cells, but not 3T3-L1 cells, was suppressed by prolactin through its receptor and downstream STAT5. Furthermore, coculture of MSF cells with mammary epithelial HC11 cells and culture in HC11-conditioned medium also suppressed adipogenic differentiation of MSF cells. We have demonstrated that adipogenic differentiation of at least some populations of mammary stromal cells is modulated by lactogenic hormones and humoral factors from epithelial cells, suggesting that the response of these mammary cells may differ from adipocytes at other sites. We believe that the MSF cell line will prove a useful model to elucidate mammary stromal adipose development in vitro as well as represent an important first step toward developing stable adipocyte cell lines that faithfully represent their site of origin.
Collapse
Affiliation(s)
- Hajime Nakatani
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | | | | | | | | | | |
Collapse
|
28
|
Furuhata Y, Nishihara M, Takahashi M. Effects of pulsatile secretion of growth hormone (GH) on fat deposition in human GH transgenic rats. Nutr Res Rev 2009; 15:231-44. [PMID: 19087406 DOI: 10.1079/nrr200243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Growth hormone (GH) is an endocrine regulator of glucose and lipid metabolism as well as body growth. GH levels are decreased and a unique pulsatile secretory pattern becomes obvious after puberty particularly in males. Coincidentally with this, males tend to deposit body fat. Experimental and clinical evidence has accumulated that obesity is associated with a decrease in GH levels. A strain of transgenic rats has been generated with severe obesity but normal nose-to-tail length, which has low circulating GH levels without pulsatility (human growth hormone (hGH) transgenic rats). The present review mainly focuses on recent and current work analysing the relationship between the occurrence of obesity and low GH levels and/or the absence of GH pulsatility in this transgenic animal model. This model has elevated blood glucose, non-esterified fatty acid, insulin and leptin levels associated with hyperphagia, suggesting that these rats also carry insulin- and leptin-resistant characteristics. hGH transgenic rats were subjected to a pair-feeding treatment to normalize food intake and chronic GH replacement to normalize GH levels. While the pair-feeding for 8 weeks successfully suppressed body-weight gain, the fat pad : body weight ratio remained very similar to freely-eating control hGH transgenic rats, which indicates the hyperphagia is not the sole contributor to the excess fat accumulation in this model. However, continuous elevation of peripheral hGH levels (approximately 2-fold) for 8 weeks by means of a slow-release vehicle resulted in a significant decrease in the fat mass : body weight ratios by 30 %. This GH treatment altered neither food intake nor body-weight gain. Thus, two characteristic phenotypes observed in the hGH transgenic rats, hyperphagia and obesity, seem to be closely related to GH levels and GH secretory pattern. This relationship might be working in the regulation of changes in seasonal body composition in wild animals.
Collapse
Affiliation(s)
- Yasufumi Furuhata
- Department of Veterinary Physiology, Veterinary Medical Science, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | | |
Collapse
|
29
|
Harkness L, Taipaleenmaki H, Mahmood A, Frandsen U, Saamanen AM, Kassem M, Abdallah BM. Isolation and Differentiation of Chondrocytic Cells Derived from Human Embryonic Stem Cells Using dlk1/FA1 as a Novel Surface Marker. Stem Cell Rev Rep 2009; 5:353-68. [DOI: 10.1007/s12015-009-9099-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
30
|
Brey CW, Nelder MP, Hailemariam T, Gaugler R, Hashmi S. Krüppel-like family of transcription factors: an emerging new frontier in fat biology. Int J Biol Sci 2009; 5:622-36. [PMID: 19841733 PMCID: PMC2757581 DOI: 10.7150/ijbs.5.622] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 09/28/2009] [Indexed: 12/26/2022] Open
Abstract
In mammals, adipose tissue stores energy in the form of fat. The ability to regulate fat storage is essential for the growth, development and reproduction of most animals, thus any abnormalities caused by excess fat accumulation can result in pathological conditions which are linked to several interrelated diseases, such as cardiovascular diseases, diabetes, and obesity. In recent years significant effort has been applied to understand basic mechanism of fat accumulation in mammalian system. Work in mouse has shown that the family of Krüppel-like factors (KLFs), a conserved and important class of transcription factors, regulates adipocyte differentiation in mammals. However, how fat storage is coordinated in response to positive and negative feedback signals is still poorly understood. To address mechanisms underlying fat storage we have studied two Caenorhabditis elegans KLFs and demonstrate that both worm klfs are key regulators of fat metabolism in C. elegans. These results provide the first in vivo evidence supporting essential regulatory roles for KLFs in fat metabolism in C. elegans and shed light on the human counterpart in disease-gene association. This finding allows us to pursue a more comprehensive approach to understand fat biology and provides an opportunity to learn about the cascade of events that regulate KLF activation, repression and interaction with other factors in exerting its biological function at an organismal level. In this review, we provide an overview of the most current information on the key regulatory components in fat biology, synthesize the diverse literature, pose new questions, and propose a new model organism for understanding fat biology using KLFs as the central theme.
Collapse
Affiliation(s)
- Christopher W Brey
- Center for Vector Biology, Rutgers University, New Brunswick, New Jersey 08901, USA
| | | | | | | | | |
Collapse
|
31
|
Gevers EF, Hannah MJ, Waters MJ, Robinson ICAF. Regulation of rapid signal transducer and activator of transcription-5 phosphorylation in the resting cells of the growth plate and in the liver by growth hormone and feeding. Endocrinology 2009; 150:3627-36. [PMID: 19359380 DOI: 10.1210/en.2008-0985] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GH has physiological functions in many tissues, but the cellular targets for direct effects of GH remain ill defined in complex tissues such as the growth plate in which the contribution of direct vs. indirect actions of GH remains controversial. The Janus kinase (Jak)-signal transducer and activator of transcription (STAT)-5 pathway is activated by GH, so we developed a method to visualize nuclear Stat5b and phosphorylated Stat5 in single cells in response to a pulse of GH. Hep2 cells did not show a Stat5 phosphorylation (pY-Stat5) response to GH except in cells transfected to express GH receptors. ATDC5 cells express GH receptors and showed GH-induced pY-Stat5 responses, which varied with their state of chondrocyte differentiation. In vivo, Stat5b(+ve) nuclei were seen in the resting and prehypertrophic chondrocytes of the growth plate. After a single ip pulse of human GH or mouse GH, but not prolactin, pY-Stat5 responses were visible in cells in the resting zone and groove of Ranvier, 10-45 min later. Prehypertrophic chondrocytes showed no pY-Stat5 response to GH. GH target cells were also identified in other tissues, and a marked variability in spatiotemporal pY-Stat5 responses was evident. Endogenous hepatic pY-Stat5 was detected in mice with intact GH secretion but only during a GH pulse. Fasting and chronic exposure to GH attenuated the pY-Stat5 response to an acute GH injection. In conclusion, pY-Stat5 responses to GH vary in time and space, are sensitive to nutritional status, and may be inhibited by prior GH exposure. In the growth plate, our data provide direct in vivo support for an early role of GH to regulate the fate of immature chondrocytes.
Collapse
Affiliation(s)
- Evelien F Gevers
- Division of Molecular Neuroendocrinology, Medical Research Council National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom.
| | | | | | | |
Collapse
|
32
|
Jacobs FMJ, van der Linden AJA, Wang Y, von Oerthel L, Sul HS, Burbach JPH, Smidt MP. Identification of Dlk1, Ptpru and Klhl1 as novel Nurr1 target genes in meso-diencephalic dopamine neurons. Development 2009; 136:2363-73. [PMID: 19515692 DOI: 10.1242/dev.037556] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The orphan nuclear receptor Nurr1 is essential for the development of meso-diencephalic dopamine (mdDA) neurons and is required, together with the homeobox transcription factor Pitx3, for the expression of genes involved in dopamine metabolism. In order to elucidate the molecular mechanisms that underlie the neuronal deficits in Nurr1(-/-) mice, we performed combined gene expression microarrays and ChIP-on-chip analysis and thereby identified Dlk1, Ptpru and Klhl1 as novel Nurr1 target genes in vivo. In line with the previously described cooperativity between Nurr1 and Pitx3, we show that the expression of Ptpru and Klhl1 in mdDA neurons is also dependent on Pitx3. Furthermore, we demonstrate that Nurr1 interacts with the Ptpru promoter directly and requires Pitx3 for full expression of Ptpru in mdDA neurons. By contrast, the expression of Dlk1 is maintained in Pitx3(-/-) embryos and is even expanded into the rostral part of the mdDA area, suggesting a unique position of Dlk1 in the Nurr1 and Pitx3 transcriptional cascades. Expression analysis in Dlk1(-/-) embryos reveals that Dlk1 is required to prevent premature expression of Dat in mdDA neuronal precursors as part of the multifaceted process of mdDA neuronal differentiation driven by Nurr1 and Pitx3. Taken together, the involvement of Nurr1 and Pitx3 in the expression of novel target genes involved in important neuronal processes such as neuronal patterning, axon outgrowth and terminal differentiation, opens up new avenues to study the properties of mdDA neurons during development and in neuronal pathology as observed in Parkinson's disease.
Collapse
Affiliation(s)
- Frank M J Jacobs
- Rudolf Magnus Institute of Neuroscience, Department of Neuroscience and Pharmacology, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
33
|
Orr B, Grace OC, Vanpoucke G, Ashley GR, Thomson AA. A role for notch signaling in stromal survival and differentiation during prostate development. Endocrinology 2009; 150:463-72. [PMID: 18801907 DOI: 10.1210/en.2008-0383] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Notch1 signaling is involved in epithelial growth and differentiation of prostate epithelia, and we have examined the role that notch signaling plays in the stroma of the developing prostate. We initially observed expression of delta-like 1 (Dlk1) and Notch2 in gene profiling studies of prostatic mesenchyme, and anticipated that they might be expressed in a key subset of inductive mesenchyme. Using quantitative RT-PCR, Northern blotting, and whole mount in situ hybridization, we confirmed that both Dlk1 and Notch2 mRNAs showed a restricted expression pattern within subsets of the stroma during prostate development. Localization of Dlk1 and Notch2 proteins mirrored the transcript expression, and showed both distinct and overlapping expression patterns within the stroma. Dlk1 and Notch2 were coexpressed in condensed inductive mesenchyme of the ventral mesenchymal pad (VMP), and were partially colocalized in the smooth muscle (SM) layer of the urethral stroma. In addition, Dlk1 was not expressed in SM adjacent to the VMP in female urethra. The function of notch signaling was examined using organ cultures of prostate rudiments and a small molecule inhibitor of notch receptor activity. Inhibition of notch signaling led to a loss of stromal tissue in both prostate and female VMP cultures, suggesting that this pathway was required for stromal survival. Inhibition of notch signaling also led to changes in both epithelial and stromal differentiation, which was evident in altered distributions of SM alpha-actin and p63 in prostates grown in vitro. The effects of notch signaling upon the stroma were only evident in the presence of testosterone, in contrast to effects upon epithelial differentiation.
Collapse
Affiliation(s)
- Brigid Orr
- Medical Research Council Human Reproductive Sciences Unit, Centre for Reproductive Biology, The Queen's Medical Research Institute, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom
| | | | | | | | | |
Collapse
|
34
|
The spatial and temporal expression of delta-like protein 1 in the rat pituitary gland during development. Histochem Cell Biol 2008; 131:141-53. [PMID: 18751720 DOI: 10.1007/s00418-008-0494-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2008] [Indexed: 10/21/2022]
Abstract
An analysis of secreted proteins by the signal sequence trap method using a cDNA library of the rat pituitary anlage at embryonic days (E) 13.5 revealed the abundant expression of delta-like protein 1 (Dlk1) in the pituitary gland. Dlk1, an epidermal growth factor-like repeat protein in preadipocytes, functions in maintaining the preadipose state. Expression of Dlk1 mRNA in the pituitary at E13.5 and in the adult pituitary was confirmed by in situ hybridization. The expression pattern of Dlk1 during pituitary development was also studied by immunohistochemistry. Dlk1 protein first appeared in Rathke's pouch and the infundibulum at E11.5; as development proceeded, expression became restricted to the pars distalis and pars tuberalis (PT). Dlk1 was expressed in most ACTH cells during the embryonic stages, but its expression was limited to only a few ACTH cells in the adult pituitary. It was also expressed in a small population of TSH, GTH, and PRL cells throughout development, whereas it was present in the cytoplasm of most GH cells at all developmental stages. Similarly, Dlk1 was localized in the cytoplasm of PT cells during development. These findings provide new insights into the mechanism of Dlk1 regarding its regulation of pituitary hormone-secreting cells during development.
Collapse
|
35
|
Hermida C, Garcés C, de Oya M, Cano B, Martínez-Costa OH, Rivero S, García-Ramírez JJ, Laborda J, Aragón JJ. The serum levels of the EGF-like homeotic protein dlk1 correlate with different metabolic parameters in two hormonally different children populations in Spain. Clin Endocrinol (Oxf) 2008; 69:216-24. [PMID: 18248640 DOI: 10.1111/j.1365-2265.2008.03170.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The Dlk1 gene encodes for dlk1, a transmembrane protein belonging to the EGF-like repeat-containing family. Dlk1 has been shown to act as a regulator of adipogenesis. Fc-dlk1 transgenic mice show a decrease in adipose tissue and glucose tolerance, hypertriglyceridaemia and lower insulin sensitivity. Dlk1-deficient mice show growth retardation, increased serum lipid metabolites and develop obesity. These data advocate for a role of dlk1 in the maintenance of lipid homeostasis, and suggest that dlk1 levels may influence the development of cardiovascular disease. AIM AND METHODS In this study, we analysed whether dlk1 serum levels could be indicative of the different hormonal or metabolic status shown by two Spanish children populations (6-8 years-old), Orense and Murcia. We determined dlk1 serum levels by ELISA assay, using an antibody raised against the recombinant protein, and performed a correlation analysis against measurements of several hormonal and biochemical parameters in samples from 494 subjects. RESULTS We found a statistically significant positive correlation between serum levels of dlk1 and those of glucose (P < 0.05), total cholesterol (P < 0.01) and high-density lipoprotein-cholesterol (HDL-C) (P < 0.01) in children from Murcia, but not from Orense's population, where dehydroepiandrosterone-sulphate (DHEA-S) levels were significantly higher (P < 0.01) and dlk1 correlated positively with insulin (P < 0.01), homeostasis model assessment (HOMA) (P < 0.01) and free fatty acids (FFA) (P < 0.05). CONCLUSIONS dlk1 serum levels appear related to the anabolic status of the children in association with changes in the levels of DHEA-S, which have been associated with hyperinsulinaemia and diabetes. Monitoring dlk1 levels may be important to evaluate the metabolic and hormonal stage of child development.
Collapse
Affiliation(s)
- Carmen Hermida
- Departamento de Bioquímica de la UAM, and Instituto de Investigaciones Biomédicas Alberto Sols UAM-CSIC, Facultad de Medicina de la Universidad Autónoma de Madrid, 28029. Madrid, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
dlk1 Specifically Interacts with Insulin-Like Growth Factor Binding Protein 1 to Modulate Adipogenesis of 3T3-L1 Cells. J Mol Biol 2008; 379:428-42. [DOI: 10.1016/j.jmb.2008.03.070] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 03/10/2008] [Accepted: 03/31/2008] [Indexed: 01/24/2023]
|
37
|
Zhou X, Li D, Yin J, Ni J, Dong B, Zhang J, Du M. CLA differently regulates adipogenesis in stromal vascular cells from porcine subcutaneous adipose and skeletal muscle. J Lipid Res 2007; 48:1701-9. [PMID: 17496270 DOI: 10.1194/jlr.m600525-jlr200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Conjugated linoleic acid (CLA), a mixture of isomers of linoleic acid, has previously been shown to be able to decrease porcine subcutaneous (SC) adipose tissue levels while increasing the count of intramuscular (IM) adipose tissue in vivo. However, the underlying mechanisms through which it acts are poorly understood. The objective of this study was to investigate the different effects of CLA on adipogenesis in cultured SC adipose tissue and IM stromal vascular cells obtained from neonatal pigs. As shown here, trans-10, cis-12 CLA decreased the expression of adipocyte-specific genes as well as adipose precursor cell numbers and the accumulation of lipid in cultured SC adipose tissue stromal vascular cells. However, the cis-9, trans-11 CLA did not alter adipogenesis in SC cultures. On the other hand, both CLA isomers increased the expression of adipocyte-specific genes in IM cultures, together with the increasing accumulation of lipid and Oil Red O-stained cells. Collectively, these data show that CLA decreases SC adipose tissue but increases IM adipose tissue by different regulation of adipocyte-specific gene expression. These results suggest that adipogenesis in IM adipocytes differs from that in SC adipocytes.
Collapse
Affiliation(s)
- Xuan Zhou
- National Key Laboratory of Animal Nutrition, China Agricultural University, Beijing 100094, China
| | | | | | | | | | | | | |
Collapse
|
38
|
Abdallah BM, Ding M, Jensen CH, Ditzel N, Flyvbjerg A, Jensen TG, Dagnaes-Hansen F, Gasser JA, Kassem M. Dlk1/FA1 is a novel endocrine regulator of bone and fat mass and its serum level is modulated by growth hormone. Endocrinology 2007; 148:3111-21. [PMID: 17446189 DOI: 10.1210/en.2007-0171] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Fat and bone metabolism are two linked processes regulated by several hormonal factors. Fetal antigen 1 (FA1) is the soluble form of dlk1 (delta-like 1), which is a member of the Notch-Delta family. We previously identified FA1 as a negative regulator of bone marrow mesenchymal stem cell differentiation. Here, we studied the effects of circulating FA1 on fat and bone mass in vivo by generating mice expressing high serum levels of FA1 (FA1 mice) using the hydrodynamic-based gene transfer procedure. We found that increased serum FA1 levels led to a significant reduction in total body weight, fat mass, and bone mass in a dose-dependent manner. Reduced bone mass in FA1 mice was associated with the inhibition of mineral apposition rate and bone formation rates by 58 and 72%, respectively. Because FA1 is colocalized with GH in the pituitary gland, we explored the possible modulation of serum FA1 by GH. Serum levels of IGF-I and IGF binding proteins did not change in FA1 mice, whereas increasing serum GH in normal mice using hydrodynamic-based gene transfer procedure dramatically reduced serum FA1 levels by 60%. Conversely, serum FA1 was increased 450% in hypophysectomized mice, and this high level was reduced by 40% during GH treatment. In conclusion, our data identify the FA1 as a novel endocrine factor regulating bone mass and fat mass in vivo, and its serum levels are regulated by GH. FA1 thus provides a novel class of developmental molecules that regulate physiological functions of the postnatal organisms.
Collapse
Affiliation(s)
- Basem M Abdallah
- Department of Endocrinology, Clinic for Molecular Endocrinology Treatment Laboratory, Odense University Hospital, Medical Biotechnology Center, University of South Denmark, DK-5000 Odense C, Denmark.
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Ansell PJ, Zhou Y, Schjeide BM, Kerner A, Zhao J, Zhang X, Klibanski A. Regulation of growth hormone expression by Delta-like protein 1 (Dlk1). Mol Cell Endocrinol 2007; 271:55-63. [PMID: 17485162 PMCID: PMC1974851 DOI: 10.1016/j.mce.2007.04.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Revised: 03/30/2007] [Accepted: 04/03/2007] [Indexed: 11/28/2022]
Abstract
Delta-like protein 1 (Dlk1) is a transmembrane protein characterized by epidermal growth factor (EGF)-like repeats. Dlk1, which is also known as preadipocyte factor 1 (pref-1) because of its ability to inhibit preadipocyte differentiation, regulates the differentiation of several other cell types through unknown mechanisms. To elucidate Dlk1 functions, identification of Dlk1-regulated target genes is critical. The observation that Dlk1 is expressed in many endocrine tissues suggests that Dlk1 may have endocrine-related functions. Because Dlk1 is expressed in GH producing cells, we hypothesize that one function of Dlk1 is to regulate GH expression. We found that GH mRNA, protein, and secretion were significantly decreased in GH3 pituitary cell clones that stably express Dlk1. In contrast, Dlk1 expression was unable to alter prolactin expression. Co-transfection of GH3 cells with a GH promoter-regulated reporter gene showed that Dlk1 repressed GH promoter activity. Deletion and mutation analysis of the GH promoter indicated that Pit-1 binding sites in the GH promoter are required for Dlk1-mediated repression. Furthermore, Dlk1 expression represses Pit-1-mediated transcription when both proteins are co-expressed in MCF-7 cells. Deletion analysis of Dlk1 revealed that the ability of Dlk1 to regulate GH promoter activity is independent of both its EGF-like repeats and its ability to modulate MAP kinase activity. The observation that Dlk1 regulates GH expression identifies the first endocrine function of Dlk1, establishes GH as a Dlk1-regulated target gene, and provides a model system to facilitate studies of Dlk1-mediated signaling.
Collapse
Affiliation(s)
- Peter J Ansell
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Bulfinch 457B, 55 Fruit Street, Boston, MA 02114, United States
| | | | | | | | | | | | | |
Collapse
|
40
|
Davies JS, Gevers EF, Stevenson AE, Coschigano KT, El-Kasti MM, Bull MJ, Elford C, Evans BAJ, Kopchick JJ, Wells T. Adiposity profile in the dwarf rat: an unusually lean model of profound growth hormone deficiency. Am J Physiol Endocrinol Metab 2007; 292:E1483-94. [PMID: 17264226 DOI: 10.1152/ajpendo.00417.2006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study describes the previously uncharacterized ontogeny and regulation of truncal adipose reserves in the profoundly GH-deficient dwarf (dw/dw) rat. We show that, despite normal proportionate food intake, dw/dw rats develop abdominal leanness and hypoleptinemia (circulating leptin halved in dw/dw males, P < 0.05) during puberty. This contrasts with the hyperleptinemia seen in moderately GH-deficient Tgr rats (circulating leptin doubled at 6 wk of age, P < 0.05) and in GH receptor-binding protein (GHR/BP)-null mice (circulating leptin doubled; P < 0.05). This lean/hypoleptinemic phenotype was not completely normalized by GH treatment, but dw/dw rats developed abdominal obesity in response to neonatal MSG treatment or maintenance on a high-fat diet. Unlike Tgr rats, dw/dw rats did not become obese with age; plasma leptin levels and fat pad weights became similar to those in wild-type rats. In contrast with truncal leanness, tibial marrow adiposity was normal in male and doubled in female dwarves (P < 0.01), this increase being attributable to increased adipocyte number (P < 0.01). Neonatal MSG treatment and high-fat feeding elevated marrow adiposity in dw/dw rats by inducing adipocyte enlargement (P < 0.05). These results demonstrate that, despite lipolytic influence of GH, severe GH deficiency in dw/dw rats is accompanied by a paradoxical leanness. This lean/hypoleptinemic phenotype is not solely attributable to reduced GH signaling and does not appear to result from a reduction in nutrient intake or the ability of dw/dw adipocytes to accumulate lipid. Disruption of preadipocyte differentiation or adipocyte proliferation in the dw/dw rat may lead to the development of this unusually lean/hypoleptinemic phenotype.
Collapse
|
41
|
Nueda ML, Baladrón V, Sánchez-Solana B, Ballesteros MA, Laborda J. The EGF-like Protein dlk1 Inhibits Notch Signaling and Potentiates Adipogenesis of Mesenchymal Cells. J Mol Biol 2007; 367:1281-93. [PMID: 17320900 DOI: 10.1016/j.jmb.2006.10.043] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Accepted: 10/10/2006] [Indexed: 10/24/2022]
Abstract
The EGF-like homeotic gene Dlk1 appears to function as an inhibitor of adipogenesis. Overexpression of Dlk1 prevents adipogenesis of 3T3-L1 cells. Dlk1-deficient mice are obese; however, adipose tissue still develops in Fc-dlk1 transgenic mice, suggesting that Dlk1 is not a strict inhibitor of adipogenesis. To clarify the role of Dlk1 in adipogenesis, we studied whether Dlk1 could act differently on this process depending upon the differentiation state of the precursor cells. We found that Dlk1 is a potentiator of adipogenesis for mesenchymal C3H10T1/2 cells. This potentiating effect can be triggered by overexpressing the entire protein or the extracellular EGF-like-containing region, but not by overexpressing the intracellular dlk1 sequence. In addition, coculture of C3H10T1/2 cells with other cells expressing Dlk1, but not with cells lacking Dlk1 expression, enhances their adipogenic response. Potentiation of adipogenesis by Dlk1 was associated with changes in the activation of ERK1/2 after IGFI/insulin induction. Finally, as reported with other cells, dlk1 functioned as a Notch signaling inhibitor in C3H10T1/2 cells, but inhibition of Notch1 expression prevented the potentiating effects of Dlk1 in adipogenesis. These data suggest that Dlk1 may potentiate or inhibit adipogenesis depending upon the cellular context, and that Notch1 expression and activation are important factors in this context.
Collapse
Affiliation(s)
- María-Luisa Nueda
- Department of Inorganic and Organic Chemistry and Biochemistry, Medical School, Regional Center for Biomedical Research, University of Castilla-La Mancha, Albacete, Spain
| | | | | | | | | |
Collapse
|
42
|
Wang Y, Sul HS. Ectodomain shedding of preadipocyte factor 1 (Pref-1) by tumor necrosis factor alpha converting enzyme (TACE) and inhibition of adipocyte differentiation. Mol Cell Biol 2006; 26:5421-35. [PMID: 16809777 PMCID: PMC1592724 DOI: 10.1128/mcb.02437-05] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 02/02/2006] [Accepted: 04/20/2006] [Indexed: 12/18/2022] Open
Abstract
Preadipocyte factor 1 (Pref-1), an epidermal growth factor repeat containing transmembrane protein found in the preadipocytes, inhibits adipocyte differentiation in vitro and in vivo. Here, we examined the processing of membrane form of Pref-1A to release the 50-kDa soluble form that inhibits adipocyte differentiation. The ectodomain cleavage of Pref-1 is markedly enhanced by phorbol 12-myristate 13-acetate in a dose- and time-dependent manner. The basal and stimulated cleavage is inhibited by the broad metalloproteinase inhibitor GM6001, a fact that suggests that cleavage of membrane Pref-1A is dependent on a metalloproteinase. Next, we showed that release of soluble Pref-1A is inhibited by TAPI-0 and by a tissue inhibitor of metalloproteinase-3, TIMP-3, that can inhibit tumor necrosis factor alpha converting enzyme (TACE), but not by TIMP-1 or TIMP-2. On the other hand, overexpression of TACE increases Pref-1 cleavage to produce the 50-kDa soluble form. Furthermore, this cleavage was not detected in cells with TACE mutation or with TACE small interfering RNA. TACE-mediated shedding of Pref-1 ectodomain inhibits adipocyte differentiation of 3T3-L1 cells and in Pref-1-null mouse embryo fibroblasts transduced with Pref-1A. Identification of TACE as the major protease responsible for conversion of membrane-bound Pref-1 to the biologically active diffusible form provides a new insight into Pref-1 function in adipocyte differentiation.
Collapse
Affiliation(s)
- Yuhui Wang
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | | |
Collapse
|
43
|
Weidman JR, Maloney KA, Jirtle RL. Comparative phylogenetic analysis reveals multiple non-imprinted isoforms of opossum Dlk1. Mamm Genome 2006; 17:157-67. [PMID: 16465595 DOI: 10.1007/s00335-005-0116-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Accepted: 10/18/2005] [Indexed: 10/25/2022]
Abstract
Imprinted genes are monoallelically expressed in a parent-of-origin manner and were previously identified in both marsupials and eutherians, but not in monotremes. Phylogenetic comparison of imprinted domains is a powerful tool for investigating the molecular and adaptive evolution of this unique gene regulatory mechanism. Herein, we report that multiple transcripts of Dlk1 (Delta, Drosophila, Homolog-like 1) are expressed in the opossum, but none are imprinted. Thus, we provide the first example of a reciprocally imprinted gene domain in which imprinting evolved in a common ancestor to eutherian rather than therian mammals. Moreover, the reciprocally imprinted Meg3 (Maternally Expressed Gene 3), found downstream of Dlk1 in eutherian mammals, is absent in the opossum. We propose that the Meg3 sequence integrated into the eutherian Dlk1 domain via a LINE-1 element and that Dlk1 became imprinted in eutherian mammals only after this downstream integration. These findings clearly demonstrate that imprinted genes did not all evolve before the divergence of marsupials and eutherians.
Collapse
Affiliation(s)
- Jennifer R Weidman
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | | | |
Collapse
|
44
|
Altenberger T, Bilban M, Auer M, Knosp E, Wolfsberger S, Gartner W, Mineva I, Zielinski C, Wagner L, Luger A. Identification of DLK1 variants in pituitary- and neuroendocrine tumors. Biochem Biophys Res Commun 2006; 340:995-1005. [PMID: 16403460 DOI: 10.1016/j.bbrc.2005.12.094] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Accepted: 12/09/2005] [Indexed: 11/19/2022]
Abstract
In a gene chip analysis of common pituitary tumor types, one of the genes with the most impressive tissue-specific expression regulation was delta-like 1 (DLK1), which was strongly expressed in GH-secreting (GH-S) pituitary tumors. In addition to pituitary adenomas, various endocrine tumors were subjected to real-time-quantitative PCR revealing high expression of DLK1 in normal pituitary tissue, in GH-S-, in one prolactin-secreting pituitary adenoma and in pheochromocytomas. Additionally, three DLK1 gene-derived subvariants were identified. The first, lacking 204 bp--coding for epidermal growth factor-like domain 6 and parts of the juxtamembrane region--was named Secredeltin. In the other two splice variants (named Brevideltin and Brevideltinin), a stop codon is introduced due to a frame-shift, leading to truncated proteins of 204 and 213 aas, respectively.
Collapse
MESH Headings
- Alternative Splicing
- Base Sequence
- Blotting, Northern
- Calcium-Binding Proteins
- Cloning, Molecular
- Codon, Terminator
- DNA/chemistry
- DNA/metabolism
- DNA, Complementary/metabolism
- Female
- Gene Expression Profiling
- Gene Expression Regulation
- Gene Expression Regulation, Neoplastic
- Genetic Variation
- Humans
- Immunoblotting
- Intercellular Signaling Peptides and Proteins
- Male
- Membrane Proteins/biosynthesis
- Membrane Proteins/chemistry
- Membrane Proteins/metabolism
- Microscopy, Confocal
- Microscopy, Fluorescence
- Models, Genetic
- Molecular Sequence Data
- Neuroendocrine Tumors/metabolism
- Oligonucleotide Array Sequence Analysis
- Ovarian Neoplasms/metabolism
- Pituitary Neoplasms/metabolism
- Polymerase Chain Reaction
- Protein Structure, Tertiary
- RNA, Messenger/metabolism
- Recombinant Proteins/chemistry
- Repressor Proteins/biosynthesis
- Repressor Proteins/chemistry
- Repressor Proteins/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Homology, Nucleic Acid
- Time Factors
Collapse
Affiliation(s)
- T Altenberger
- Vienna Medical University, Department of Internal Medicine III, Vienna, Austria.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Xu XQ, Emerald BS, Goh ELK, Kannan N, Miller LD, Gluckman PD, Liu ET, Lobie PE. Gene Expression Profiling to Identify Oncogenic Determinants of Autocrine Human Growth Hormone in Human Mammary Carcinoma. J Biol Chem 2005; 280:23987-4003. [PMID: 15845533 DOI: 10.1074/jbc.m503869200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have exploited a discrepancy in the oncogenic potential of autocrine and exogenous human growth hormone (hGH) in an attempt to identify molecules that could potentially be involved in oncogenic transformation of the human mammary epithelial cell. Microarray analysis of 19,000 human genes identified a subset of 305 genes in a human mammary carcinoma cell line that were remarkably different in their response to autocrine and exogenous hGH. Autocrine and exogenous hGH also regulated 167 common genes. Semiquantitative reverse transcription-PCR confirmed differential regulation of genes by either autocrine or exogenous hGH. Functional analysis of one of the identified autocrine hGH-regulated genes, TFF3, determined that its expression is sufficient to support anchorage-independent growth of human mammary carcinoma cells. Small interfering RNA-mediated knockdown of TFF3 concordantly abrogated anchorage-independent growth of mammary carcinoma cells and abrogated the ability of autocrine hGH to stimulate oncogenic transformation of immortalized human mammary epithelial cells. Further functional characterization of the identified subset of specifically autocrine hGH regulated genes will delineate additional novel oncogenes for the human mammary epithelial cell.
Collapse
Affiliation(s)
- Xiu Qin Xu
- Microarray and Expression Genomics, Genome Institute of Singapore, Republic of Singapore
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Hsiao CC, Huang CC, Sheen JM, Tai MH, Chen CM, Huang LLH, Chuang JH. Differential expression of delta-like gene and protein in neuroblastoma, ganglioneuroblastoma and ganglioneuroma. Mod Pathol 2005; 18:656-62. [PMID: 15605081 DOI: 10.1038/modpathol.3800335] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neuroblastoma is an extremely malignant solid tumor in children, characterized by spontaneous differentiation and regression. An epidermal growth factor-like homeotic protein, delta-like (dlk), has been involved in differentiation of neuroblastoma cell lines, but is unknown in in vivo expression of neuroblastoma. By using in situ hybridization and immunohistochemistry, dlk mRNA and protein expression were studied in formalin-fixed archival tissues from 10 patients with neuroblastoma, five with ganglioneuroblastoma, and five with ganglioneuroma. Three adrenal tissues from children died of diseases other than adrenal tumors and one from an adult with pheochromocytoma were severed as normal and disease controls. The results showed strong immunoreactive dlk staining in endothelial cells in neuroblastoma, ganglioneuroblastoma and ganglioneuroma. Dlk was detectable in mature neuromatous stroma and gangliocytes of ganglioneuroma, but not in neuroblasts of neuroblastoma and ganglioneuroblastoma, neither in gangliocytes of ganglioneuroblastoma. In contrast, dlk mRNA expression was mainly observed in the gangliocytes, but was less intense in the neuroblasts and neuromatous stroma cells. Endothelial cells were essentially devoid of dlk mRNA expression. The findings indicated that there is differential expression of dlk gene and protein among neuroblastoma, ganglioneuroblastoma and ganglioneuroma. The stronger expression of dlk in gangliocytes in ganglioneuroma, in contrast to weaker or no expression in gangliocytes in ganglioneuroblastoma and neuroblasts in neuroblastoma, suggests upregulation of dlk during differentiation of neuroblastoma into more benign form. Furthermore, higher dlk protein expression in the tumor endothelium than in the endothelium of normal adrenal gland implies that dlk may regulate the endothelial function in neuroblastic tumors.
Collapse
Affiliation(s)
- Chih-Cheng Hsiao
- Department of Pediatrics, Division of Hematology/Oncology, Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | | | | | | | | | | | | |
Collapse
|
47
|
Karlsen AE, Heding PE, Frobøse H, Rønn SG, Kruhøffer M, Orntoft TF, Darville M, Eizirik DL, Pociot F, Nerup J, Mandrup-Poulsen T, Billestrup N. Suppressor of cytokine signalling (SOCS)-3 protects beta cells against IL-1beta-mediated toxicity through inhibition of multiple nuclear factor-kappaB-regulated proapoptotic pathways. Diabetologia 2004; 47:1998-2011. [PMID: 15578154 DOI: 10.1007/s00125-004-1568-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Accepted: 07/22/2004] [Indexed: 10/26/2022]
Abstract
AIMS/HYPOTHESIS The proinflammatory cytokine IL-1beta induces apoptosis in pancreatic beta cells via pathways dependent on nuclear factor-kappaB (NF-kappaB), mitogen-activated protein kinase, and protein kinase C. We recently showed suppressor of cytokine signalling (SOCS)-3 to be a natural negative feedback regulator of IL-1beta- and IFN-gamma-mediated signalling in rat islets and beta cell lines, preventing their deleterious effects. However, the mechanisms underlying SOCS-3 inhibition of IL-1beta signalling and prevention against apoptosis remain unknown. METHODS The effect of SOCS-3 expression on the global gene-expression profile following IL-1beta exposure was microarray-analysed using a rat beta cell line (INS-1) with inducible SOCS-3 expression. Subsequently, functional analyses were performed. RESULTS Eighty-two known genes and several expressed sequence tags (ESTs) changed expression level 2.5-fold or more in response to IL-1beta alone. Following 6 h of IL-1beta exposure, 23 transcripts were up-regulated. Of these, several, including all eight transcripts relating to immune/inflammatory response pathways, were suppressed by SOCS-3. Following 24 h of IL-1beta exposure, secondary response genes were detected, affecting metabolism, energy generation, protein synthesis and degradation, growth arrest, and apoptosis. The majority of these changes were prevented by SOCS-3 expression. Multiple IL-1beta-induced NF-kappaB-dependent proapoptotic early response genes were inhibited by SOCS-3 expression, suggesting that SOCS-3 inhibits NF-kappaB-mediated signalling. These observations were experimentally confirmed in functional analyses. CONCLUSIONS/INTERPRETATION This study suggests that there is an unexpected cross-talk between the SOCS/IFN and the IL-1beta pathways of signalling in pancreatic beta cells, which could lead to a novel perspective of blocking two important proapoptotic pathways in pancreatic beta cells by influencing a single signalling molecule, namely SOCS-3.
Collapse
Affiliation(s)
- A E Karlsen
- Steno Diabetes Center, Niels Steensensvej 2, 2820 Gentofte, Denmark.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Klöting N, Klöting I. Congenic mapping of type 1 diabetes—protective gene(s) in an interval of 4Mb on rat chromosome 6q32. Biochem Biophys Res Commun 2004; 323:388-94. [PMID: 15369764 DOI: 10.1016/j.bbrc.2004.08.104] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Indexed: 11/29/2022]
Abstract
Congenic BB.SHR rats introgressing a segment of SHR chromosome 6 onto BB/OK background showed a reduction of diabetes frequency by 72% compared with BB/OK. To identify underlying gene(s), the introgressed segment was shortened and the expression of seven genes (Yy1, Dlk1/Pref-1, Wd40 repeat, Cdc42, Rtl1, Traf3, and Tnfaip2) was studied in blood and spleen of non-diabetic BB/OK, BB.6S, and SHR males and females at an age of 30, 70, and 90 days. The phenotype of congenic sublines narrowed the diabetes-protective region to 4 Mb. The relative expression of Yy1 and Pref-1 in blood and of Pref-1 in spleen was significantly reduced by 50-90% in male and female BB.6S and SHR compared with BB/OK favouring Yy1 and Pref-1 as candidate genes. All other genes were differently expressed according to gender and strain.
Collapse
Affiliation(s)
- Nora Klöting
- Department of Laboratory Animal Science, Medical Faculty, University of Greifswald, Karlsburg, Germany.
| | | |
Collapse
|
49
|
Abstract
The use of experimental models is the foundation of experimental biology, so it is important to know how much the models can tell us about actual animals. Inconsistent or contradictory results from in vitro models are often associated with the perception that a particular model or results are somehow wrong and therefore cannot tell us anything important about how an animal works. In fact, in vitro conditions do not create new biology. Differences between in vitro and in vivo behavior can only result from the actual cellular repertoire, which provides a powerful tool to uncover new information. Adipose tissue research provides a useful context for examining this issue because the regulation of adipose growth and metabolism has important economic implications for livestock production. Examples are discussed in which either excess skepticism or narrow interpretation of results slowed progress toward our current understanding of adipose biology. Similarly, contemporary examples using genomics are used to suggest that large inconsistencies are still apparent with in vitro methods. Careful consideration of these inconsistencies may provide new insights.
Collapse
Affiliation(s)
- J Novakofski
- Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
| |
Collapse
|
50
|
Abdallah BM, Jensen CH, Gutierrez G, Leslie RGQ, Jensen TG, Kassem M. Regulation of human skeletal stem cells differentiation by Dlk1/Pref-1. J Bone Miner Res 2004; 19:841-52. [PMID: 15068508 DOI: 10.1359/jbmr.040118] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2003] [Revised: 12/08/2003] [Accepted: 01/16/2004] [Indexed: 12/20/2022]
Abstract
UNLABELLED Dlk-1/Pref-1 was identified as a novel regulator of human skeletal stem cell differentiation. Dlk1/Pref-1 is expressed in bone and cultured osteoblasts, and its constitutive overexpression led to inhibition of osteoblast and adipocyte differentiation of human marrow stromal cells. INTRODUCTION Molecular control of human mesenchymal stem cell (hMSC) differentiation into osteoblasts and adipocytes is not known. In this study, we examined the role of delta-like 1/preadipocyte factor-1 (Dlk1/Pref-1) in regulating the differentiation of hMSCs. MATERIALS AND METHODS As a model for hMSCs, we have stably transduced telomerase-immortalized hMSC (hMSC-TERT) with the full length of human Dlk1/Pref-1 cDNA and tested its effect on hMSC growth and differentiation into osteoblasts or adipocytes as assessed by cytochemical staining, FACS analysis, and real time PCR. Ex vivo calvaria organ cultures assay was used to confirm the in vitro effect of Dlk/Pref-1 on bone formation. RESULTS Dlk1/Pref-1 was found to be expressed in fetal and adult bone, hMSCs, and some osteoblastic cell lines. A retroviral vector containing the human Dlk1/Pref-1 cDNA was used to create a cell line (hMSC-dlk1) expressing high levels of Dlk1/Pref-1 protein. Overexpression of Dlk1/Pref-1 did not affect the proliferation rate of hMSC, but the ability to form mature adipocytes, mineralized matrix in vitro, and new bone formation in neonatal murine calvariae organ cultures was reduced. These effects were associated with inhibition of gene expression markers of late stages of adipocyte (adipocyte fatty acid-binding protein [aP2], peroxisome proliferator-activated receptor-gamma2 [PPARgamma2], and adiponectin [APM1]) and osteoblast differentiation (alkaline phosphatase [ALP], collagen type I [Col1], and osteocalcin [OC]). Lineage commitment markers for adipocytes (adipocyte determination and differentiation factor -1 [ADD1]) and osteoblasts (core binding factor/runt-related binding factor 2 [Cbfa1/Runx2]) were not affected. CONCLUSION During hMSC differentiation, Dlk1/Pref-1 maintains the size of the bipotential progenitor cell pool by inhibiting the formation of mature osteoblasts and adipocytes.
Collapse
Affiliation(s)
- Basem M Abdallah
- Department of Endocrinology, Univerity Hospital of Odense, Odense, Denmark
| | | | | | | | | | | |
Collapse
|