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Chen SM, Hsiao CW, Chen YJ, Hong CJ, Lin JC, Yang CP, Chang YH. Interleukin-4 inhibits the hypothalamic appetite control by modulating the insulin-AKT and JAK-STAT signaling in leptin mutant mice. ENVIRONMENTAL TOXICOLOGY 2024; 39:3980-3990. [PMID: 38597583 DOI: 10.1002/tox.24264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/19/2024] [Accepted: 03/23/2024] [Indexed: 04/11/2024]
Abstract
Our previous research identified interleukin-4 (IL-4) as a key regulator of glucose/lipid metabolism, circulatory leptin levels, and insulin action, suggesting its potential as a therapeutic target for obesity and related complications. This study aimed to further elucidate the role of IL-4 in regulating hypothalamic appetite-controlling neuropeptides using leptin dysfunctional Leptin145E/145E mice as the experimental model. IL-4 significantly reduces body weight, food intake, and serum glucose levels. Our data demonstrated that IL-4 exhibits multiple functions in regulating hypothalamic appetite control, including downregulating orexigenic agouti-related peptide and neuropeptide Y levels, promoting expression of anorexigenic proopiomelanocortin, alleviating microenvironmental hypothalamic inflammation, enhancing leptin and insulin pathway, and attenuating insulin resistance. Furthermore, IL-4 promotes uncoupling protein 1 expression of white adipose tissue (WAT), suggesting its role in triggering WAT-beige switch. In summary, this study uncovers novel function of IL-4 in mediating food-intake behaviors and metabolic efficiency by regulating hypothalamic appetite-control and WAT browning activities. These findings support the therapeutic potential of targeting hypothalamic inflammation and reducing adiposity through IL-4 intervention for tackling the pandemic increasing prevalence of obesity and associated metabolic disorders.
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Affiliation(s)
- Shu-Mei Chen
- Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan
| | - Chiao-Wan Hsiao
- Institute of Brain Science of National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yen-Ju Chen
- Research Assistant Center, Tainan Municipal Hospital (Managed by Show Chwan Medical Care Corporation), Tainan, Taiwan
| | - Chen-Jee Hong
- Section of Psychosomatic Medicine, Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jung-Chun Lin
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Ching-Ping Yang
- Department of Medical Technology, Jenteh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yih-Hsin Chang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
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Interleukin-4 Improves Metabolic Abnormalities in Leptin-Deficient and High-Fat Diet Mice. Int J Mol Sci 2020; 21:ijms21124451. [PMID: 32585823 PMCID: PMC7352748 DOI: 10.3390/ijms21124451] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 12/25/2022] Open
Abstract
Obesity is a metabolic disorder that results from complex interactions between genetic predisposition and dietary factors. Interleukin-4 (IL-4), besides its role in immunity, has metabolic effects on insulin efficacy. We studied the effects of IL-4 on metabolic abnormalities in a mice model of obesity involving leptin deficiency and leptin resistance. Leptin-deficient 145E and leptin-resistant high-fat diet (HFD) mice showed lower levels of circulating IL-4. 145E and HFD mice showed a number of abnormalities: Obesity, hyperglycemia, hyperinsulinemia, insulin resistance, dyslipidemia, liver injury, and adiposity with concurrent inflammation, decreases in Akt, signal transducer and activator of transcription 3 (STAT3), and STAT6 phosphorylation in the hypothalamus, liver, and epididymal fat. Independent of leptin-deficient obesity and dietary obesity, a course of 8-week IL-4 supplementation improved obesity and impairment in Akt, STAT3, and STAT6 signaling. Amelioration of cytokine expression, despite variable extents, was closely linked with the actions of IL-4. Additionally, the browning of white adipocytes by IL-4 was found in epididymal white adipose tissues and 3T3-L1 preadipocytes. Chronic exercise, weight management, and probiotics are recommended to overweight patients and IL-4 signaling is associated with clinical improvement. Thus, IL-4 could be a metabolic regulator and antiobesity candidate for the treatment of obesity and its complications.
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Danielsson J, Noel JK, Simien JM, Duggan BM, Oliveberg M, Onuchic JN, Jennings PA, Haglund E. The Pierced Lasso Topology Leptin has a Bolt on Dynamic Domain Composed by the Disordered Loops I and III. J Mol Biol 2020; 432:3050-3063. [PMID: 32081588 DOI: 10.1016/j.jmb.2020.01.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 01/18/2020] [Accepted: 01/24/2020] [Indexed: 02/08/2023]
Abstract
Leptin is an important signaling hormone, mostly known for its role in energy expenditure and satiety. Furthermore, leptin plays a major role in other proteinopathies, such as cancer, marked hyperphagia, impaired immune function, and inflammation. In spite of its biological relevance in human health, there are no NMR resonance assignments of the human protein available, obscuring high-resolution characterization of the soluble protein and/or its conformational dynamics, suggested as being important for receptor interaction and biological activity. Here, we report the nearly complete backbone resonance assignments of human leptin. Chemical shift-based secondary structure prediction confirms that in solution leptin forms a four-helix bundle including a pierced lasso topology. The conformational dynamics, determined on several timescales, show that leptin is monomeric, has a rigid four-helix scaffold, and a dynamic domain, including a transiently formed helix. The dynamic domain is anchored to the helical scaffold by a secondary hydrophobic core, pinning down the long loops of leptin to the protein body, inducing motional restriction without a well-defined secondary or tertiary hydrogen bond stabilized structure. This dynamic region is well suited for and may be involved in functional allosteric dynamics upon receptor binding.
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Affiliation(s)
- Jens Danielsson
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
| | | | | | - Brendan Michael Duggan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, USA
| | - Mikael Oliveberg
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - José Nelson Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, USA; Department of Physics and Astronomy, Department of Chemistry, And Department of Biosciences, Rice University, Houston, USA
| | - Patricia Ann Jennings
- Department of Chemistry and Biochemistry, The University of California at San Diego, La Jolla, USA
| | - Ellinor Haglund
- The Department of Chemistry, University of Hawaii, Manoa, Honolulu, USA.
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Yupanqui-Lozno H, Bastarrachea RA, Yupanqui-Velazco ME, Alvarez-Jaramillo M, Medina-Méndez E, Giraldo-Peña AP, Arias-Serrano A, Torres-Forero C, Garcia-Ordoñez AM, Mastronardi CA, Restrepo CM, Rodriguez-Ayala E, Nava-Gonzalez EJ, Arcos-Burgos M, Kent JW, Cole SA, Licinio J, Celis-Regalado LG. Congenital Leptin Deficiency and Leptin Gene Missense Mutation Found in Two Colombian Sisters with Severe Obesity. Genes (Basel) 2019; 10:genes10050342. [PMID: 31067764 PMCID: PMC6562380 DOI: 10.3390/genes10050342] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/23/2019] [Accepted: 04/30/2019] [Indexed: 12/16/2022] Open
Abstract
Background: Congenital leptin deficiency is a recessive genetic disorder associated with severe early-onset obesity. It is caused by mutations in the leptin (LEP) gene, which encodes the protein product leptin. These mutations may cause nonsense-mediated mRNA decay, defective secretion or the phenomenon of biologically inactive leptin, but typically lead to an absence of circulating leptin, resulting in a rare type of monogenic extreme obesity with intense hyperphagia, and serious metabolic abnormalities. Methods: We present two severely obese sisters from Colombia, members of the same lineal consanguinity. Their serum leptin was measured by MicroELISA. DNA sequencing was performed on MiSeq equipment (Illumina) of a next-generation sequencing (NGS) panel involving genes related to severe obesity, including LEP. Results: Direct sequencing of the coding region of LEP gene in the sisters revealed a novel homozygous missense mutation in exon 3 [NM_002303.3], C350G>T [p.C117F]. Detailed information and clinical measurements of these sisters were also collected. Their serum leptin levels were undetectable despite their markedly elevated fat mass. Conclusions: The mutation of LEP, absence of detectable leptin, and the severe obesity found in these sisters provide the first evidence of monogenic leptin deficiency reported in the continents of North and South America.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Claudio A Mastronardi
- NeuRos, Instituto de Medicina Traslacional, Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá 111711, Colombia.
| | - Carlos M Restrepo
- GeniURos, CIGGUR, Instituto de Medicina Traslacional, Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá 111711, Colombia.
| | | | | | - Mauricio Arcos-Burgos
- Grupo de Investigación en Psiquiatría (GIPSI), Instituto de Investigaciones Médicas. Facultad de Medicina, Universidad de Antioquia, Medellín 050010, Colombia.
| | - Jack W Kent
- Texas Biomedical Research Institute, San Antonio, TX 78227, USA.
| | - Shelley A Cole
- Texas Biomedical Research Institute, San Antonio, TX 78227, USA.
| | - Julio Licinio
- SUNY Upstate Medical University, Syracuse, NY 13210, USA.
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Haglund E, Nguyen L, Schafer NP, Lammert H, Jennings PA, Onuchic JN. Uncovering the molecular mechanisms behind disease-associated leptin variants. J Biol Chem 2018; 293:12919-12933. [PMID: 29950524 PMCID: PMC6102133 DOI: 10.1074/jbc.ra118.003957] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 06/14/2018] [Indexed: 01/21/2023] Open
Abstract
The pleiotropic hormone leptin has a pivotal role in regulating energy balance by inhibiting hunger and increasing energy expenditure. Homozygous mutations found in the leptin gene are associated with extreme obesity, marked hyperphagia, and impaired immune function. Although these mutations have been characterized in vivo, a detailed understanding of how they affect leptin structure and function remains elusive. In the current work, we used NMR, differential scanning calorimetry, molecular dynamics simulations, and bioinformatics calculations to characterize the effects of these mutations on leptin structure and function and binding to its cognate receptor. We found that mutations identified in patients with congenital leptin deficiency not only cause leptin misfolding or aggregation, but also cause changes in the dynamics of leptin residues on the receptor-binding interface. Therefore, we infer that mutation-induced leptin deficiency may arise from several distinct mechanisms including (i) blockade of leptin receptor interface II, (ii) decreased affinity in the second step of leptin's interaction with its receptor, (iii) leptin destabilization, and (iv) unsuccessful threading through the covalent loop, leading to leptin misfolding/aggregation. We propose that this expanded framework for understanding the mechanisms underlying leptin deficiency arising from genetic mutations may be useful in designing therapeutics for leptin-associated disorders.
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Affiliation(s)
- Ellinor Haglund
- Center for Theoretical Biological Physics, and Biosciences, Rice University, Houston, Texas 77005.
| | - Lannie Nguyen
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093
| | - Nicholas Peter Schafer
- Center for Theoretical Biological Physics, and Biosciences, Rice University, Houston, Texas 77005
| | - Heiko Lammert
- Center for Theoretical Biological Physics, and Biosciences, Rice University, Houston, Texas 77005
| | - Patricia Ann Jennings
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093.
| | - José Nelson Onuchic
- Center for Theoretical Biological Physics, and Biosciences, Rice University, Houston, Texas 77005; Departments of Physics and Astronomy, Chemistry, and Biosciences, Rice University, Houston, Texas 77005.
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6
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Identification of mutations through dominant screening for obesity using C57BL/6 substrains. Sci Rep 2016; 6:32453. [PMID: 27585985 PMCID: PMC5009433 DOI: 10.1038/srep32453] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/10/2016] [Indexed: 01/05/2023] Open
Abstract
The discovery of leptin substantiated the usefulness of a forward genetic approach in elucidating the molecular network regulating energy metabolism. However, no successful dominant screening for obesity has been reported, which may be due to the influence of quantitative trait loci between the screening and counter strains and the low fertility of obese mice. Here, we performed a dominant screening for obesity using C57BL/6 substrains, C57BL/6J and C57BL/6N, with the routine use of in vitro fertilization. The screening of more than 5000 mutagenized mice established two obese pedigrees in which single nucleotide substitutions in Mc4r and Sim1 genes were identified through whole-exome sequencing. The mutation in the Mc4r gene produces a premature stop codon, and the mutant SIM1 protein lacks transcriptional activity, showing that the haploinsufficiency of SIM1 and MC4R results in obesity. We further examined the hypothalamic neuropeptide expressions in the mutant pedigrees and mice with diet-induced obesity, which showed that each obesity mouse model has distinct neuropeptide expression profiles. This forward genetic screening scheme is useful and applicable to any research field in which mouse models work.
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Wabitsch M, Funcke JB, Lennerz B, Kuhnle-Krahl U, Lahr G, Debatin KM, Vatter P, Gierschik P, Moepps B, Fischer-Posovszky P. Biologically inactive leptin and early-onset extreme obesity. N Engl J Med 2015; 372:48-54. [PMID: 25551525 DOI: 10.1056/nejmoa1406653] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mutations in the gene encoding leptin (LEP) typically lead to an absence of circulating leptin and to extreme obesity. We describe a 2-year-old boy with early-onset extreme obesity due to a novel homozygous transversion (c.298G→T) in LEP, leading to a change from aspartic acid to tyrosine at amino acid position 100 (p.D100Y) and high immunoreactive levels of leptin. Overexpression studies confirmed that the mutant protein is secreted but neither binds to nor activates the leptin receptor. The mutant protein failed to reduce food intake and body weight in leptin-deficient ob/ob mice. Treatment of the patient with recombinant human leptin (metreleptin) rapidly normalized eating behavior and resulted in weight loss.
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Affiliation(s)
- Martin Wabitsch
- From the Division of Pediatric Endocrinology and Diabetes (M.W., J.-B.F., B.L., P.F.-P.), Department of Pediatrics and Adolescent Medicine (G.L., K.-M.D.), and the Institute of Pharmacology and Toxicology (P.V., P.G., B.M.), University of Ulm, Ulm; and Endokrinologische Schwerpunktpraxis für Kinder- und Jugendliche, Gauting (U.K.-K.) - both in Germany
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8
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Odle AK, Haney A, Allensworth-James M, Akhter N, Childs GV. Adipocyte versus pituitary leptin in the regulation of pituitary hormones: somatotropes develop normally in the absence of circulating leptin. Endocrinology 2014; 155:4316-28. [PMID: 25116704 PMCID: PMC4197982 DOI: 10.1210/en.2014-1172] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Leptin is a cytokine produced by white fat cells, skeletal muscle, the placenta, and the pituitary gland among other tissues. Best known for its role in regulating appetite and energy expenditure, leptin is produced largely by and in proportion to white fat cells. Leptin is also important to the maintenance and function of the GH cells of the pituitary. This was shown when the deletion of leptin receptors on somatotropes caused decreased numbers of GH cells, decreased circulating GH, and adult-onset obesity. To determine the source of leptin most vital to GH cells and other pituitary cell types, we compared two different leptin knockout models with Cre-lox technology. The global Lep-null model is like the ob/ob mouse, whereby only the entire exon 3 is deleted. The selective adipocyte-Lep-null model lacks adipocyte leptin but retains pituitary leptin, allowing us to investigate the pituitary as a potential source of circulating leptin. Male and female mice lacking adipocyte leptin (Adipocyte-lep-null) did not produce any detectable circulating leptin and were infertile, suggesting that the pituitary does not contribute to serum levels. In the presence of only pituitary leptin, however, these same mutants were able to maintain somatotrope numbers and GH mRNA levels. Serum GH trended low, but values were not significant. However, hypothalamic GHRH mRNA was significantly reduced in these animals. Other serum hormone and pituitary mRNA differences were observed, some of which varied from previous results reported in ob/ob animals. Whereas pituitary leptin is capable of maintaining somatotrope numbers and GH mRNA production, the decreased hypothalamic GHRH mRNA and low (but not significant) serum GH levels indicate an important role for adipocyte leptin in the regulation of GH secretion in the mouse. Thus, normal GH secretion may require the coordinated actions of both adipocyte and pituitary leptin.
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Affiliation(s)
- Angela K Odle
- Department of Neurobiology and Developmental Sciences, College of Medicine, Center for Translational Neurosciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
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9
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Funcke JB, von Schnurbein J, Lennerz B, Lahr G, Debatin KM, Fischer-Posovszky P, Wabitsch M. Monogenic forms of childhood obesity due to mutations in the leptin gene. Mol Cell Pediatr 2014; 1:3. [PMID: 26567097 PMCID: PMC4644131 DOI: 10.1186/s40348-014-0003-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 06/29/2014] [Indexed: 12/20/2022] Open
Abstract
Congenital leptin deficiency is a rare autosomal recessive monogenic obesity syndrome caused by mutations in the leptin gene. This review describes the molecular and cellular characteristics of the eight distinct mutations found so far in humans.
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Affiliation(s)
- Jan-Bernd Funcke
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, 89075, Germany.
| | - Julia von Schnurbein
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, 89075, Germany.
| | - Belinda Lennerz
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, 89075, Germany.
| | - Georgia Lahr
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, 89075, Germany.
| | - Klaus-Michael Debatin
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, 89075, Germany.
| | - Pamela Fischer-Posovszky
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, 89075, Germany.
| | - Martin Wabitsch
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, 89075, Germany.
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10
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Hughey CC, Wasserman DH, Lee-Young RS, Lantier L. Approach to assessing determinants of glucose homeostasis in the conscious mouse. Mamm Genome 2014; 25:522-38. [PMID: 25074441 DOI: 10.1007/s00335-014-9533-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/04/2014] [Indexed: 01/11/2023]
Abstract
Obesity and type 2 diabetes lessen the quality of life of those afflicted and place considerable burden on the healthcare system. Furthermore, the detrimental impact of these pathologies is expected to persist or even worsen. Diabetes is characterized by impaired insulin action and glucose homeostasis. This has led to a rapid increase in the number of mouse models of metabolic disease being used in the basic sciences to assist in facilitating a greater understanding of the metabolic dysregulation associated with obesity and diabetes, the identification of therapeutic targets, and the discovery of effective treatments. This review briefly describes the most frequently utilized models of metabolic disease. A presentation of standard methods and technologies on the horizon for assessing metabolic phenotypes in mice, with particular emphasis on glucose handling and energy balance, is provided. The article also addresses issues related to study design, selection and execution of metabolic tests of glucose metabolism, the presentation of data, and interpretation of results.
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Affiliation(s)
- Curtis C Hughey
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, 823 Light Hall, 2215 Garland Ave, Nashville, TN, 37232, USA,
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11
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Caignard G, Leiva-Torres GA, Leney-Greene M, Charbonneau B, Dumaine A, Fodil-Cornu N, Pyzik M, Cingolani P, Schwartzentruber J, Dupaul-Chicoine J, Guo H, Saleh M, Veillette A, Lathrop M, Blanchette M, Majewski J, Pearson A, Vidal SM. Genome-wide mouse mutagenesis reveals CD45-mediated T cell function as critical in protective immunity to HSV-1. PLoS Pathog 2013; 9:e1003637. [PMID: 24068938 PMCID: PMC3771889 DOI: 10.1371/journal.ppat.1003637] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 07/24/2013] [Indexed: 01/15/2023] Open
Abstract
Herpes simplex encephalitis (HSE) is a lethal neurological disease resulting from infection with Herpes Simplex Virus 1 (HSV-1). Loss-of-function mutations in the UNC93B1, TLR3, TRIF, TRAF3, and TBK1 genes have been associated with a human genetic predisposition to HSE, demonstrating the UNC93B-TLR3-type I IFN pathway as critical in protective immunity to HSV-1. However, the TLR3, UNC93B1, and TRIF mutations exhibit incomplete penetrance and represent only a minority of HSE cases, perhaps reflecting the effects of additional host genetic factors. In order to identify new host genes, proteins and signaling pathways involved in HSV-1 and HSE susceptibility, we have implemented the first genome-wide mutagenesis screen in an in vivo HSV-1 infectious model. One pedigree (named P43) segregated a susceptible trait with a fully penetrant phenotype. Genetic mapping and whole exome sequencing led to the identification of the causative nonsense mutation L3X in the Receptor-type tyrosine-protein phosphatase C gene (Ptprc(L3X)), which encodes for the tyrosine phosphatase CD45. Expression of MCP1, IL-6, MMP3, MMP8, and the ICP4 viral gene were significantly increased in the brain stems of infected Ptprc(L3X) mice accounting for hyper-inflammation and pathological damages caused by viral replication. Ptprc(L3X) mutation drastically affects the early stages of thymocytes development but also the final stage of B cell maturation. Transfer of total splenocytes from heterozygous littermates into Ptprc(L3X) mice resulted in a complete HSV-1 protective effect. Furthermore, T cells were the only cell population to fully restore resistance to HSV-1 in the mutants, an effect that required both the CD4⁺ and CD8⁺ T cells and could be attributed to function of CD4⁺ T helper 1 (Th1) cells in CD8⁺ T cell recruitment to the site of infection. Altogether, these results revealed the CD45-mediated T cell function as potentially critical for infection and viral spread to the brain, and also for subsequent HSE development.
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Affiliation(s)
- Grégory Caignard
- Departments of Human Genetics and Medicine, McGill University, Montréal, Quebec, Canada
| | | | - Michael Leney-Greene
- Departments of Human Genetics and Medicine, McGill University, Montréal, Quebec, Canada
| | - Benoit Charbonneau
- Departments of Human Genetics and Medicine, McGill University, Montréal, Quebec, Canada
| | - Anne Dumaine
- Departments of Human Genetics and Medicine, McGill University, Montréal, Quebec, Canada
| | - Nassima Fodil-Cornu
- Departments of Human Genetics and Medicine, McGill University, Montréal, Quebec, Canada
| | - Michal Pyzik
- Departments of Human Genetics and Medicine, McGill University, Montréal, Quebec, Canada
| | - Pablo Cingolani
- School of Computer Science and McGill Centre for Bioinformatics, McGill University, Montréal, Quebec, Canada
| | | | | | - Huaijian Guo
- Laboratory of Molecular Oncology, Clinical Research Institute of Montréal, Montréal, Quebec, Canada
| | - Maya Saleh
- Departments of Biochemistry and Medicine, McGill University, Montréal, Quebec, Canada
| | - André Veillette
- Laboratory of Molecular Oncology, Clinical Research Institute of Montréal, Montréal, Quebec, Canada
| | - Marc Lathrop
- McGill University and Genome Québec Innovation Centre, Montréal, Quebec, Canada
| | - Mathieu Blanchette
- School of Computer Science and McGill Centre for Bioinformatics, McGill University, Montréal, Quebec, Canada
| | - Jacek Majewski
- McGill University and Genome Québec Innovation Centre, Montréal, Quebec, Canada
| | - Angela Pearson
- INRS-Institut Armand-Frappier, Université du Québec, Laval, Quebec, Canada
| | - Silvia M. Vidal
- Departments of Human Genetics and Medicine, McGill University, Montréal, Quebec, Canada
- * E-mail:
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Loh NY, Bentley L, Dimke H, Verkaart S, Tammaro P, Gorvin CM, Stechman MJ, Ahmad BN, Hannan FM, Piret SE, Evans H, Bellantuono I, Hough TA, Fraser WD, Hoenderop JGJ, Ashcroft FM, Brown SDM, Bindels RJM, Cox RD, Thakker RV. Autosomal dominant hypercalciuria in a mouse model due to a mutation of the epithelial calcium channel, TRPV5. PLoS One 2013; 8:e55412. [PMID: 23383183 PMCID: PMC3559602 DOI: 10.1371/journal.pone.0055412] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 12/22/2012] [Indexed: 12/05/2022] Open
Abstract
Hypercalciuria is a major cause of nephrolithiasis, and is a common and complex disorder involving genetic and environmental factors. Identification of genetic factors for monogenic forms of hypercalciuria is hampered by the limited availability of large families, and to facilitate such studies, we screened for hypercalciuria in mice from an N-ethyl-N-nitrosourea mutagenesis programme. We identified a mouse with autosomal dominant hypercalciuria (HCALC1). Linkage studies mapped the Hcalc1 locus to a 11.94 Mb region on chromosome 6 containing the transient receptor potential cation channel, subfamily V, members 5 (Trpv5) and 6 (Trpv6) genes. DNA sequence analysis of coding regions, intron-exon boundaries and promoters of Trpv5 and Trpv6 identified a novel T to C transition in codon 682 of TRPV5, mutating a conserved serine to a proline (S682P). Compared to wild-type littermates, heterozygous (Trpv5682P/+) and homozygous (Trpv5682P/682P) mutant mice had hypercalciuria, polyuria, hyperphosphaturia and a more acidic urine, and ∼10% of males developed tubulointerstitial nephritis. Trpv5682P/682P mice also had normal plasma parathyroid hormone but increased 1,25-dihydroxyvitamin D3 concentrations without increased bone resorption, consistent with a renal defect for the hypercalciuria. Expression of the S682P mutation in human embryonic kidney cells revealed that TRPV5-S682P-expressing cells had a lower baseline intracellular calcium concentration than wild-type TRPV5-expressing cells, suggesting an altered calcium permeability. Immunohistological studies revealed a selective decrease in TRPV5-expression from the renal distal convoluted tubules of Trpv5682P/+ and Trpv5682P/682P mice consistent with a trafficking defect. In addition, Trpv5682P/682P mice had a reduction in renal expression of the intracellular calcium-binding protein, calbindin-D28K, consistent with a specific defect in TRPV5-mediated renal calcium reabsorption. Thus, our findings indicate that the TRPV5 S682P mutant is functionally significant and study of HCALC1, a novel model for autosomal dominant hypercalciuria, may help further our understanding of renal calcium reabsorption and hypercalciuria.
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Affiliation(s)
- Nellie Y. Loh
- Academic Endocrine Unit, Nuffield Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, United Kingdom
| | - Liz Bentley
- MRC Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council, Harwell, Oxfordshire, United Kingdom
| | - Henrik Dimke
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Sjoerd Verkaart
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Paolo Tammaro
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Caroline M. Gorvin
- Academic Endocrine Unit, Nuffield Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, United Kingdom
| | - Michael J. Stechman
- Academic Endocrine Unit, Nuffield Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, United Kingdom
| | - Bushra N. Ahmad
- Academic Endocrine Unit, Nuffield Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, United Kingdom
| | - Fadil M. Hannan
- Academic Endocrine Unit, Nuffield Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, United Kingdom
| | - Sian E. Piret
- Academic Endocrine Unit, Nuffield Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, United Kingdom
| | - Holly Evans
- Academic Unit of Bone Biology, University of Sheffield, The Medical School, Sheffield, United Kingdom
| | - Ilaria Bellantuono
- Academic Unit of Bone Biology, University of Sheffield, The Medical School, Sheffield, United Kingdom
| | - Tertius A. Hough
- MRC Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council, Harwell, Oxfordshire, United Kingdom
| | - William D. Fraser
- Faculty of Medical and Health Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Joost G. J. Hoenderop
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Frances M. Ashcroft
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Steve D. M. Brown
- MRC Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council, Harwell, Oxfordshire, United Kingdom
| | - René J. M. Bindels
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Roger D. Cox
- MRC Mammalian Genetics Unit and Mary Lyon Centre, Medical Research Council, Harwell, Oxfordshire, United Kingdom
| | - Rajesh V. Thakker
- Academic Endocrine Unit, Nuffield Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Churchill Hospital, Headington, Oxford, United Kingdom
- * E-mail:
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13
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Abstract
Mammalian spermatogenesis is a complex developmental program in which a diploid progenitor germ cell transforms into highly specialized spermatozoa. One intriguing aspect of sperm production is the dynamic change in membrane lipid composition that occurs throughout spermatogenesis. Cholesterol content, as well as its intermediates, differs vastly between the male reproductive system and nongonadal tissues. Accumulation of cholesterol precursors such as testis meiosis-activating sterol and desmosterol is observed in testes and spermatozoa from several mammalian species. Moreover, cholesterogenic genes, especially meiosis-activating sterol-producing enzyme cytochrome P450 lanosterol 14α-demethylase, display stage-specific expression patterns during spermatogenesis. Discrepancies in gene expression patterns suggest a complex temporal and cell-type specific regulation of sterol compounds during spermatogenesis, which also involves dynamic interactions between germ and Sertoli cells. The functional importance of sterol compounds in sperm production is further supported by the modulation of sterol composition in spermatozoal membranes during epididymal transit and in the female reproductive tract, which is a prerequisite for successful fertilization. However, the exact role of sterols in male reproduction is unknown. This review discusses sterol dynamics in sperm maturation and describes recent methodological advances that will help to illuminate the complexity of sperm formation and function.
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Affiliation(s)
- Rok Keber
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Groblje 3, 1230 Domžale, Slovenia
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14
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Bongfen SE, Rodrigue-Gervais IG, Berghout J, Torre S, Cingolani P, Wiltshire SA, Leiva-Torres GA, Letourneau L, Sladek R, Blanchette M, Lathrop M, Behr MA, Gruenheid S, Vidal SM, Saleh M, Gros P. An N-ethyl-N-nitrosourea (ENU)-induced dominant negative mutation in the JAK3 kinase protects against cerebral malaria. PLoS One 2012; 7:e31012. [PMID: 22363534 PMCID: PMC3283600 DOI: 10.1371/journal.pone.0031012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 12/29/2011] [Indexed: 11/19/2022] Open
Abstract
Cerebral malaria (CM) is a lethal neurological complication of malaria. We implemented a genome-wide screen in mutagenized mice to identify host proteins involved in CM pathogenesis and whose inhibition may be of therapeutic value. One pedigree (P48) segregated a resistance trait whose CM-protective effect was fully penetrant, mapped to chromosome 8, and identified by genome sequencing as homozygosity for a mis-sense mutation (W81R) in the FERM domain of Janus-associated kinase 3 (Jak3). The causative effect of Jak3(W81R) was verified by complementation testing in Jak3(W81R/-) double heterozygotes that were fully protected against CM. Jak3(W81R) homozygotes showed defects in thymic development with depletion of CD8(+) T cell, B cell, and NK cell compartments, and defective T cell-dependent production of IFN-γ. Adoptive transfer of normal splenocytes abrogates CM resistance in Jak3(W81R) homozygotes, an effect attributed to the CD8(+) T cells. Jak3(W81R) behaves as a dominant negative variant, with significant CM resistance of Jak3(W81R/+) heterozygotes, compared to CM-susceptible Jak3(+/+) and Jak3(+/-) controls. CM resistance in Jak3(W81R/+) heterozygotes occurs in presence of normal T, B and NK cell numbers. These findings highlight the pathological role of CD8(+) T cells and Jak3-dependent IFN-γ-mediated Th1 responses in CM pathogenesis.
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Affiliation(s)
- Silayuv E. Bongfen
- Department of Biochemistry, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
| | - Ian-Gael Rodrigue-Gervais
- Department of Medicine, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
| | - Joanne Berghout
- Department of Biochemistry, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
| | - Sabrina Torre
- Department of Human Genetics, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
| | - Pablo Cingolani
- School of Computer Science, McGill University, Montreal, Canada
| | - Sean A. Wiltshire
- Department of Human Genetics, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
| | - Gabriel A. Leiva-Torres
- Department of Human Genetics, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
| | - Louis Letourneau
- Department of Human Genetics, McGill University, Montreal, Canada
| | - Robert Sladek
- Department of Human Genetics, McGill University, Montreal, Canada
| | | | - Mark Lathrop
- Institut de Génomique, Centre National de Génotypage, Evry, France
| | - Marcel A. Behr
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
- The McGill University Health Center, Montreal, Canada
| | - Samantha Gruenheid
- Complex Traits Group, McGill University, Montreal, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
| | - Silvia M. Vidal
- Department of Human Genetics, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
| | - Maya Saleh
- Department of Medicine, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
| | - Philippe Gros
- Department of Biochemistry, McGill University, Montreal, Canada
- Department of Human Genetics, McGill University, Montreal, Canada
- Complex Traits Group, McGill University, Montreal, Canada
- * E-mail:
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