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Lorenz J, Richter S, Kirstein AS, Kolbig F, Nebe M, Schulze M, Kiess W, Spitzbarth I, Klöting N, Le Duc D, Baschant U, Garten A. Pten knockout in mouse preosteoblasts leads to changes in bone turnover and strength. JBMR Plus 2024; 8:ziad016. [PMID: 38505222 PMCID: PMC10945711 DOI: 10.1093/jbmrpl/ziad016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 11/30/2023] [Accepted: 12/07/2023] [Indexed: 03/21/2024] Open
Abstract
Bone development and remodeling are controlled by the phosphoinositide-3-kinase (Pi3k) signaling pathway. We investigated the effects of downregulation of phosphatase and tensin homolog (Pten), a negative regulator of Pi3k signaling, in a mouse model of Pten deficiency in preosteoblasts. We aimed to identify mechanisms that are involved in the regulation of bone turnover and are linked to bone disorders. Femora, tibiae, and bone marrow stromal cells (BMSCs) isolated from mice with a conditional deletion of Pten (Pten cKO) in Osterix/Sp7-expressing osteoprogenitor cells were compared to Cre-negative controls. Bone phenotyping was performed by μCT measurements, bone histomorphometry, quantification of bone turnover markers CTX and procollagen type 1 N propeptide (P1NP), and three-point bending test. Proliferation of BMSCs was measured by counting nuclei and Ki-67-stained cells. In vitro, osteogenic differentiation capacity was determined by ALP staining, as well as by detecting gene expression of osteogenic markers. BMSCs from Pten cKO mice were functionally different from control BMSCs. Osteogenic markers were increased in BMSCs derived from Pten cKO mice, while Pten protein expression was lower and Akt phosphorylation was increased. We detected a higher trabecular bone volume and an altered cortical bone morphology in Pten cKO bones with a progressive decrease in bone and tissue mineral density. Pten cKO bones displayed fewer osteoclasts and more osteoblasts (P = .00095) per trabecular bone surface and a higher trabecular bone formation rate. Biomechanical analysis revealed a significantly higher bone strength (P = .00012 for males) and elasticity of Pten cKO femora. On the cellular level, both proliferation and osteogenic differentiation capacity of Pten cKO BMSCs were significantly increased compared to controls. Our findings suggest that Pten knockout in osteoprogenitor cells increases bone stability and elasticity by increasing trabecular bone mass and leads to increased proliferation and osteogenic differentiation of BMSCs.
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Affiliation(s)
- Judith Lorenz
- Pediatric Research Center, Leipzig University, University Hospital for Children and Adolescents, Department for Child and Adolescent Medicine, 04103 Leipzig, Germany
| | - Sandy Richter
- Pediatric Research Center, Leipzig University, University Hospital for Children and Adolescents, Department for Child and Adolescent Medicine, 04103 Leipzig, Germany
| | - Anna S Kirstein
- Pediatric Research Center, Leipzig University, University Hospital for Children and Adolescents, Department for Child and Adolescent Medicine, 04103 Leipzig, Germany
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Florentien Kolbig
- Pediatric Research Center, Leipzig University, University Hospital for Children and Adolescents, Department for Child and Adolescent Medicine, 04103 Leipzig, Germany
| | - Michèle Nebe
- Pediatric Research Center, Leipzig University, University Hospital for Children and Adolescents, Department for Child and Adolescent Medicine, 04103 Leipzig, Germany
| | - Marco Schulze
- Saxon Incubator for Clinical Translation (SIKT), Leipzig University, 04103 Leipzig, Germany
| | - Wieland Kiess
- Pediatric Research Center, Leipzig University, University Hospital for Children and Adolescents, Department for Child and Adolescent Medicine, 04103 Leipzig, Germany
| | - Ingo Spitzbarth
- Faculty of Veterinary Medicine, Institute of Veterinary Pathology, Leipzig University, 04103 Leipzig, Germany
| | - Nora Klöting
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München, Leipzig University and University Hospital Leipzig, 04103 Leipzig, Germany
| | - Diana Le Duc
- Institute of Human Genetics, Leipzig University, 04103 Leipzig, Germany
| | - Ulrike Baschant
- Department of Medicine III, Technische Universität Dresden, 01309 Dresden, Germany
| | - Antje Garten
- Pediatric Research Center, Leipzig University, University Hospital for Children and Adolescents, Department for Child and Adolescent Medicine, 04103 Leipzig, Germany
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Kiess W, Kirstein AS, Kratzsch J, Gesing J, Pfäffle R. Thyroid - what is a healthy thyroid function test? J Pediatr Endocrinol Metab 2023; 36:223-224. [PMID: 36775974 DOI: 10.1515/jpem-2023-0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Affiliation(s)
- Wieland Kiess
- Hospital for Children and Adolescents, University of Leipzig, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Anna S Kirstein
- Hospital for Children and Adolescents, University of Leipzig, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Jürgen Kratzsch
- Hospital for Children and Adolescents, University of Leipzig, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Julia Gesing
- Hospital for Children and Adolescents, University of Leipzig, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Roland Pfäffle
- Hospital for Children and Adolescents, University of Leipzig, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
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Kiess W, Stoltze A, Kirstein AS, Gesing J, Stein R, Körner A, Pfäffle R. Disorders of sex development - biologic, genetic, cultural, societal, and psychologic diversity of the human nature. J Pediatr Endocrinol Metab 2023; 36:1-3. [PMID: 36480478 DOI: 10.1515/jpem-2022-0595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Wieland Kiess
- University of Leipzig Hospital for Children and Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Anette Stoltze
- University of Leipzig Hospital for Children and Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Anna S Kirstein
- University of Leipzig Hospital for Children and Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Julia Gesing
- University of Leipzig Hospital for Children and Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Robert Stein
- University of Leipzig Hospital for Children and Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Antje Körner
- University of Leipzig Hospital for Children and Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Roland Pfäffle
- University of Leipzig Hospital for Children and Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
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Barth LAG, Nebe M, Kalwa H, Velluva A, Kehr S, Kolbig F, Prabutzki P, Kiess W, Le Duc D, Garten A, Kirstein AS. Phospholipid Scramblase 4 (PLSCR4) Regulates Adipocyte Differentiation via PIP3-Mediated AKT Activation. Int J Mol Sci 2022; 23:ijms23179787. [PMID: 36077184 PMCID: PMC9456373 DOI: 10.3390/ijms23179787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Phospholipid scramblase 4 (PLSCR4) is a member of a conserved enzyme family with high relevance for the remodeling of phospholipid distribution in the plasma membrane and the regulation of cellular signaling. While PLSCR1 and -3 are involved in the regulation of adipose-tissue expansion, the role of PLSCR4 is so far unknown. PLSCR4 is significantly downregulated in an adipose-progenitor-cell model of deficiency for phosphatase and tensin homolog (PTEN). PTEN acts as a tumor suppressor and antagonist of the growth and survival signaling phosphoinositide 3-kinase (PI3K)/AKT cascade by dephosphorylating phosphatidylinositol-3,4,5-trisphosphate (PIP3). Patients with PTEN germline deletion frequently develop lipomas. The underlying mechanism for this aberrant adipose-tissue growth is incompletely understood. PLSCR4 is most highly expressed in human adipose tissue, compared with other phospholipid scramblases, suggesting a specific role of PLSCR4 in adipose-tissue biology. In cell and mouse models of lipid accumulation, we found PLSCR4 to be downregulated. We observed increased adipogenesis in PLSCR4-knockdown adipose progenitor cells, while PLSCR4 overexpression attenuated lipid accumulation. PLSCR4 knockdown was associated with increased PIP3 levels and the activation of AKT. Our results indicated that PLSCR4 is a regulator of PI3K/AKT signaling and adipogenesis and may play a role in PTEN-associated adipose-tissue overgrowth and lipoma formation.
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Affiliation(s)
- Lisa A. G. Barth
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, 04103 Leipzig, Germany
| | - Michèle Nebe
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, 04103 Leipzig, Germany
| | - Hermann Kalwa
- Institute of Pharmacology, Pharmacy and Toxicology, Leipzig University, 04107 Leipzig, Germany
| | - Akhil Velluva
- Institute of Human Genetics, Leipzig University Medical Center, 04103 Leipzig, Germany
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
| | - Stephanie Kehr
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, Leipzig University, 04107 Leipzig, Germany
| | - Florentien Kolbig
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, 04103 Leipzig, Germany
| | - Patricia Prabutzki
- Institute for Medical Physics and Biophysics, Leipzig University, 04107 Leipzig, Germany
| | - Wieland Kiess
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, 04103 Leipzig, Germany
| | - Diana Le Duc
- Institute of Human Genetics, Leipzig University Medical Center, 04103 Leipzig, Germany
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
| | - Antje Garten
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, 04103 Leipzig, Germany
| | - Anna S. Kirstein
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, 04103 Leipzig, Germany
- Correspondence: ; Tel.: +49-341-972-6504
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Körner MB, Velluva A, Bundalian L, Radtke M, Lin CC, Zacher P, Bartolomaeus T, Kirstein AS, Mrestani A, Scholz N, Platzer K, Teichmann AC, Hentschel J, Langenhan T, Lemke JR, Garten A, Abou Jamra R, Le Duc D. Altered gene expression profiles impair the nervous system development in individuals with 15q13.3 microdeletion. Sci Rep 2022; 12:13507. [PMID: 35931711 PMCID: PMC9356015 DOI: 10.1038/s41598-022-17604-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 07/28/2022] [Indexed: 11/21/2022] Open
Abstract
The 15q13.3 microdeletion has pleiotropic effects ranging from apparently healthy to severely affected individuals. The underlying basis of the variable phenotype remains elusive. We analyzed gene expression using blood from three individuals with 15q13.3 microdeletion and brain cortex tissue from ten mice Df[h15q13]/+. We assessed differentially expressed genes (DEGs), protein–protein interaction (PPI) functional modules, and gene expression in brain developmental stages. The deleted genes’ haploinsufficiency was not transcriptionally compensated, suggesting a dosage effect may contribute to the pathomechanism. DEGs shared between tested individuals and a corresponding mouse model show a significant overlap including genes involved in monogenic neurodevelopmental disorders. Yet, network-wide dysregulatory effects suggest the phenotype is not caused by a single critical gene. A significant proportion of blood DEGs, silenced in adult brain, have maximum expression during the prenatal brain development. Based on DEGs and their PPI partners we identified altered functional modules related to developmental processes, including nervous system development. We show that the 15q13.3 microdeletion has a ubiquitous impact on the transcriptome pattern, especially dysregulation of genes involved in brain development. The high phenotypic variability seen in 15q13.3 microdeletion could stem from an increased vulnerability during brain development, instead of a specific pathomechanism.
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Affiliation(s)
- Marek B Körner
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103, Leipzig, Germany.,Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany
| | - Akhil Velluva
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103, Leipzig, Germany.,Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103, Leipzig, Germany
| | - Linnaeus Bundalian
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany
| | - Maximilian Radtke
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany
| | - Chen-Ching Lin
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan
| | - Pia Zacher
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany.,Epilepsy Center Kleinwachau, 01454, Radeberg, Germany
| | - Tobias Bartolomaeus
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany
| | - Anna S Kirstein
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103, Leipzig, Germany
| | - Achmed Mrestani
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103, Leipzig, Germany.,Department of Neurology, University of Leipzig Medical Center, 04103, Leipzig, Germany
| | - Nicole Scholz
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103, Leipzig, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany
| | | | - Julia Hentschel
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany
| | - Tobias Langenhan
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103, Leipzig, Germany
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany
| | - Antje Garten
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103, Leipzig, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany.
| | - Diana Le Duc
- Institute of Human Genetics, University of Leipzig Medical Center, 04103, Leipzig, Germany. .,Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103, Leipzig, Germany.
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Nebe M, Kehr S, Schmitz S, Breitfeld J, Lorenz J, Le Duc D, Stadler PF, Meiler J, Kiess W, Garten A, Kirstein AS. Small integral membrane protein 10 like 1 downregulation enhances differentiation of adipose progenitor cells. Biochem Biophys Res Commun 2022; 604:57-62. [PMID: 35290761 DOI: 10.1016/j.bbrc.2022.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 03/02/2022] [Indexed: 11/02/2022]
Abstract
Small integral membrane protein 10 like 1 (SMIM10L1) was identified by RNA sequencing as the most significantly downregulated gene in Phosphatase and Tensin Homologue (PTEN) knockdown adipose progenitor cells (APCs). PTEN is a tumor suppressor that antagonizes the growth promoting Phosphoinositide 3-kinase (PI3K)/AKT/mechanistic Target of Rapamycin (mTOR) cascade. Diseases caused by germline pathogenic variants in PTEN are summarized as PTEN Hamartoma Tumor Syndrome (PHTS). This overgrowth syndrome is associated with lipoma formation, especially in pediatric patients. The mechanisms underlying this adipose tissue dysfunction remain elusive. We observed that SMIM10L1 downregulation in APCs led to an enhanced adipocyte differentiation in two- and three-dimensional cell culture and increased expression of adipogenesis markers. Furthermore, SMIM10L1 knockdown cells showed a decreased expression of PTEN, pointing to a mutual crosstalk between PTEN and SMIM10L1. In line with these observations, SMIM10L1 knockdown cells showed increased activation of PI3K/AKT/mTOR signaling and concomitantly increased expression of the adipogenic transcription factor SREBP1. We computationally predicted an α-helical structure and membrane association of SMIM10L1. These results support a specific role for SMIM10L1 in regulating adipogenesis, potentially by increasing PI3K/AKT/mTOR signaling, which might be conducive to lipoma formation in pediatric patients with PHTS.
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Affiliation(s)
- Michèle Nebe
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Stephanie Kehr
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany
| | - Samuel Schmitz
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Jana Breitfeld
- Medical Department III-Endocrinology, Nephrology, Rheumatology, Leipzig University Medical Center, Leipzig, Germany
| | - Judith Lorenz
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Diana Le Duc
- Institute of Human Genetics, Leipzig University Medical Center, Leipzig, Germany; Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany; Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA; Institute of Drug Discovery, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Wieland Kiess
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Antje Garten
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Anna S Kirstein
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany.
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Affiliation(s)
- Wieland Kiess
- Hospital for Children and Adolescents, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Anna S Kirstein
- Hospital for Children and Adolescents, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Robert Stein
- Hospital for Children and Adolescents, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Mandy Vogel
- Hospital for Children and Adolescents, Center for Pediatric Research, University of Leipzig, Leipzig, Germany
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Gjermeni E, Kirstein AS, Kolbig F, Kirchhof M, Bundalian L, Katzmann JL, Laufs U, Blüher M, Garten A, Le Duc D. Obesity-An Update on the Basic Pathophysiology and Review of Recent Therapeutic Advances. Biomolecules 2021; 11:biom11101426. [PMID: 34680059 PMCID: PMC8533625 DOI: 10.3390/biom11101426] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/16/2021] [Accepted: 09/22/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity represents a major public health problem with a prevalence increasing at an alarming rate worldwide. Continuous intensive efforts to elucidate the complex pathophysiology and improve clinical management have led to a better understanding of biomolecules like gut hormones, antagonists of orexigenic signals, stimulants of fat utilization, and/or inhibitors of fat absorption. In this article, we will review the pathophysiology and pharmacotherapy of obesity including intersection points to the new generation of antidiabetic drugs. We provide insight into the effectiveness of currently approved anti-obesity drugs and other therapeutic avenues that can be explored.
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Affiliation(s)
- Erind Gjermeni
- Department of Electrophysiology, Heart Center Leipzig at University of Leipzig, 04289 Leipzig, Germany;
- Department of Cardiology, Median Centre for Rehabilitation Schmannewitz, 04774 Dahlen, Germany;
| | - Anna S. Kirstein
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany; (A.S.K.); (F.K.); (A.G.)
| | - Florentien Kolbig
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany; (A.S.K.); (F.K.); (A.G.)
| | - Michael Kirchhof
- Department of Cardiology, Median Centre for Rehabilitation Schmannewitz, 04774 Dahlen, Germany;
| | - Linnaeus Bundalian
- Institute of Human Genetics, University Medical Center Leipzig, 04103 Leipzig, Germany;
| | - Julius L. Katzmann
- Klinik und Poliklinik für Kardiologie, University Clinic Leipzig, 04103 Leipzig, Germany; (J.L.K.); (U.L.)
| | - Ulrich Laufs
- Klinik und Poliklinik für Kardiologie, University Clinic Leipzig, 04103 Leipzig, Germany; (J.L.K.); (U.L.)
| | - Matthias Blüher
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, 04103 Leipzig, Germany;
| | - Antje Garten
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany; (A.S.K.); (F.K.); (A.G.)
| | - Diana Le Duc
- Institute of Human Genetics, University Medical Center Leipzig, 04103 Leipzig, Germany;
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, 04103 Leipzig, Germany;
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
- Correspondence:
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Kirstein AS, Kehr S, Nebe M, Hanschkow M, Barth LAG, Lorenz J, Penke M, Breitfeld J, Le Duc D, Landgraf K, Körner A, Kovacs P, Stadler PF, Kiess W, Garten A. PTEN regulates adipose progenitor cell growth, differentiation, and replicative aging. J Biol Chem 2021; 297:100968. [PMID: 34273354 PMCID: PMC8350019 DOI: 10.1016/j.jbc.2021.100968] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/17/2021] [Accepted: 07/13/2021] [Indexed: 12/12/2022] Open
Abstract
The tumor suppressor phosphatase and tensin homolog (PTEN) negatively regulates the insulin signaling pathway. Germline PTEN pathogenic variants cause PTEN hamartoma tumor syndrome (PHTS), associated with lipoma development in children. Adipose progenitor cells (APCs) lose their capacity to differentiate into adipocytes during continuous culture, whereas APCs from lipomas of patients with PHTS retain their adipogenic potential over a prolonged period. It remains unclear which mechanisms trigger this aberrant adipose tissue growth. To investigate the role of PTEN in adipose tissue development, we performed functional assays and RNA-Seq of control and PTEN knockdown APCs. Reduction of PTEN levels using siRNA or CRISPR led to enhanced proliferation and differentiation of APCs. Forkhead box protein O1 (FOXO1) transcriptional activity is known to be regulated by insulin signaling, and FOXO1 was downregulated at the mRNA level while its inactivation through phosphorylation increased. FOXO1 phosphorylation initiates the expression of the lipogenesis-activating transcription factor sterol regulatory element-binding protein 1 (SREBP1). SREBP1 levels were higher after PTEN knockdown and may account for the observed enhanced adipogenesis. To validate this, we overexpressed constitutively active FOXO1 in PTEN CRISPR cells and found reduced adipogenesis, accompanied by SREBP1 downregulation. We observed that PTEN CRISPR cells showed less senescence compared with controls and the senescence marker CDKN1A (p21) was downregulated in PTEN knockdown cells. Cellular senescence was the most significantly enriched pathway found in RNA-Seq of PTEN knockdown versus control cells. These results provide evidence that PTEN is involved in the regulation of APC proliferation, differentiation, and senescence, thereby contributing to aberrant adipose tissue growth in patients with PHTS.
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Affiliation(s)
- Anna S Kirstein
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany.
| | - Stephanie Kehr
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany
| | - Michèle Nebe
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Martha Hanschkow
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Lisa A G Barth
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Judith Lorenz
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Melanie Penke
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Jana Breitfeld
- Medical Department III-Endocrinology, Nephrology, Rheumatology, Leipzig University Medical Center, Leipzig, Germany
| | - Diana Le Duc
- Institute of Human Genetics, Leipzig University Medical Center, Leipzig, Germany; Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Kathrin Landgraf
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Antje Körner
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Peter Kovacs
- Medical Department III-Endocrinology, Nephrology, Rheumatology, Leipzig University Medical Center, Leipzig, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany; Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany
| | - Wieland Kiess
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany
| | - Antje Garten
- University Hospital for Children & Adolescents, Center for Pediatric Research, Leipzig University, Leipzig, Germany; Institute for Metabolism and Systems Research, University of Birmingham, Birmingham, UK
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10
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Kirstein AS, Augustin A, Penke M, Cea M, Körner A, Kiess W, Garten A. The Novel Phosphatidylinositol-3-Kinase (PI3K) Inhibitor Alpelisib Effectively Inhibits Growth of PTEN-Haploinsufficient Lipoma Cells. Cancers (Basel) 2019; 11:E1586. [PMID: 31627436 PMCID: PMC6826943 DOI: 10.3390/cancers11101586] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 01/08/2023] Open
Abstract
Germline mutations in the tumor suppressor gene PTEN cause PTEN Hamartoma Tumor Syndrome (PHTS). Pediatric patients with PHTS frequently develop lipomas. Treatment attempts with the mTORC1 inhibitor rapamycin were unable to reverse lipoma growth. Recently, lipomas associated with PIK3CA-related overgrowth syndrome were successfully treated with the novel PI3K inhibitor alpelisib. Here, we tested whether alpelisib has growth-restrictive effects and induces cell death in lipoma cells. We used PTEN-haploinsufficient lipoma cells from three patients and treated them with alpelisib alone or in combination with rapamycin. We tested the effect of alpelisib on viability, proliferation, cell death, induction of senescence, adipocyte differentiation, and signaling at 1-100 µM alpelisib. Alpelisib alone or in combination with rapamycin reduced proliferation in a concentration- and time-dependent manner. No cell death but an induction of senescence was detected after alpelisib incubation for 72 h. Alpelisib treatment led to a reduced phosphorylation of AKT, mTOR, and ribosomal protein S6. Rapamycin treatment alone led to increased AKT phosphorylation. This effect could be reversed by combining rapamycin with alpelisib. Alpelisib reduced the size of lipoma spheroids by attenuating adipocyte differentiation. Since alpelisib was well tolerated in first clinical trials, this drug alone or in combination with rapamycin is a potential new treatment option for PHTS-related adipose tissue overgrowth.
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Affiliation(s)
- Anna S Kirstein
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany.
| | - Adrien Augustin
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany.
- Faculty of Medicine, University of Liège, 4000 Liege, Belgium.
| | - Melanie Penke
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany.
| | - Michele Cea
- Chair of Hematology, Department of Internal Medicine (DiMI), University of Genoa, 16100 Genoa, Italy.
- IRCCS Polyclinic Hospital San Martino, 16100 Genoa, Italy.
| | - Antje Körner
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany.
| | - Wieland Kiess
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany.
| | - Antje Garten
- Pediatric Research Center, University Hospital for Children and Adolescents, Leipzig University, 04103 Leipzig, Germany.
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK.
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