Growth hormone receptor-deficient pigs resemble the pathophysiology of human Laron syndrome and reveal altered activation of signaling cascades in the liver
| Autor: | Martin Bidlingmaier, Birgit Rathkolb, Martin Hrabĕ de Angelis, Arne Hinrichs, Werner F. Blum, Sebastian Bultmann, Heinrich Leonhardt, Maik Dahlhoff, Simone Renner, Andreas Blutke, Eckhard Wolf, Barbara Kessler, Andreas Hoeflich, Hiroshi Nagashima, Maren Bernau, Mayuko Kurome, Rüdiger Wanke, Elisabeth Kemter, Armin M. Scholz |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Insulin-like growth factor 1 Swine INSR insulin receptor medicine.medical_treatment 4EBP1 eukaryotic initiation factor 4E binding protein 1 IGFBP3 Dwarfism IGF1 insulin-like growth factor 1 Growth hormone receptor PCR polymerase chain reaction LDL low-density lipoprotein Laron syndrome STAT5 Transcription Factor Insulin-Like Growth Factor I LSM least squares mean CRISPR/Cas clustered regularly interspaced short palindromic repeats/CRISPR-associated JAK2 Janus kinase 2 Adiposity mTOR mechanistic target of rapamycin HOMA homeostatic model assessment DXA dual-energy X-ray absorptiometry ELISA enzyme-linked immunosorbent assay Pig model eIF4E eukaryotic translation initiation factor 4E AKT serine-threonine protein kinase PPARG peroxisome proliferator-activated receptor gamma STAT signal transducer and activator of transcription GHR growth hormone receptor LPL lipoprotein lipase Liver mTORC mTOR complex S6K protein S6 kinase 1 Original Article IRS1 insulin receptor substrate 1 Growth Hormone Receptor Laron Syndrome Pig Model Hypoglycemia Insulin-like Growth Factor 1 Signaling HSL hormone-sensitive lipase PI3K phosphoinositide 3 kinase hormones hormone substitutes and hormone antagonists Signal Transduction medicine.medical_specialty lcsh:Internal medicine aa amino acid HDL high-density lipoprotein IgG immunoglobulin G Mechanistic Target of Rapamycin Complex 2 Biology 03 medical and health sciences GSK3B glycogen synthase 3 beta Internal medicine medicine Animals LS Laron syndrome lcsh:RC31-1245 Molecular Biology Leptin receptor DAB 3 3′-diaminobenzidine SE standard error Growth factor Body Weight sgRNA single guide RNA Cell Biology Receptors Somatotropin Janus Kinase 2 medicine.disease IRS1 GH growth hormone TBS Tris-buffered saline Insulin receptor Insulin-Like Growth Factor Binding Protein 2 AMPK AMP-activated protein kinase 030104 developmental biology Endocrinology Insulin-Like Growth Factor Binding Protein 3 IGFBP IGF-binding protein LEPR leptin receptor Growth Hormone biology.protein RIA radioimmunoassay MRI magnetic resonance imaging MAPK mitogen-activated protein kinase |
| Zdroj: | Molecular Metabolism, Vol 11, Iss, Pp 113-128 (2018) Molecular Metabolism Mol. Metab. 11, 113-128 (2018) Molecular metabolism, 11: 113-128 |
| ISSN: | 2212-8778 |
| Popis: | Objective Laron syndrome (LS) is a rare, autosomal recessive disorder in humans caused by loss-of-function mutations of the growth hormone receptor (GHR) gene. To establish a large animal model for LS, pigs with GHR knockout (KO) mutations were generated and characterized. Methods CRISPR/Cas9 technology was applied to mutate exon 3 of the GHR gene in porcine zygotes. Two heterozygous founder sows with a 1-bp or 7-bp insertion in GHR exon 3 were obtained, and their heterozygous F1 offspring were intercrossed to produce GHR-KO, heterozygous GHR mutant, and wild-type pigs. Since the latter two groups were not significantly different in any parameter investigated, they were pooled as the GHR expressing control group. The characterization program included body and organ growth, body composition, endocrine and clinical-chemical parameters, as well as signaling studies in liver tissue. Results GHR-KO pigs lacked GHR and had markedly reduced serum insulin-like growth factor 1 (IGF1) levels and reduced IGF-binding protein 3 (IGFBP3) activity but increased IGFBP2 levels. Serum GH concentrations were significantly elevated compared with control pigs. GHR-KO pigs had a normal birth weight. Growth retardation became significant at the age of five weeks. At the age of six months, the body weight of GHR-KO pigs was reduced by 60% compared with controls. Most organ weights of GHR-KO pigs were reduced proportionally to body weight. However, the weights of liver, kidneys, and heart were disproportionately reduced, while the relative brain weight was almost doubled. GHR-KO pigs had a markedly increased percentage of total body fat relative to body weight and displayed transient juvenile hypoglycemia along with decreased serum triglyceride and cholesterol levels. Analysis of insulin receptor related signaling in the liver of adult fasted pigs revealed increased phosphorylation of IRS1 and PI3K. In agreement with the loss of GHR, phosphorylation of STAT5 was significantly reduced. In contrast, phosphorylation of JAK2 was significantly increased, possibly due to the increased serum leptin levels and increased hepatic leptin receptor expression and activation in GHR-KO pigs. In addition, increased mTOR phosphorylation was observed in GHR-KO liver samples, and phosphorylation studies of downstream substrates suggested the activation of mainly mTOR complex 2. Conclusion GHR-KO pigs resemble the pathophysiology of LS and are an interesting model for mechanistic studies and treatment trials. Highlights • GHR-deficient pigs reveal postnatal growth retardation, disproportionate organ growth and an increased total body fat content. • GHR-deficient pigs show markedly reduced serum IGF1 and IGFBP3 levels, and transient juvenile hypoglycemia. • Increased expression and phosphorylation of IRS1 in liver of adult GHR-deficient pigs suggest increased insulin sensitivity. • Increased phosphorylation of JAK2 in liver of GHR-deficient pigs may be explained by higher serum leptin levels and activation of hepatic LEPR. |
| Databáze: | OpenAIRE |
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