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Bisgaard LS, Christensen PM, Oh J, Torta F, Füchtbauer EM, Nielsen LB, Christoffersen C. Kidney derived apolipoprotein M and its role in acute kidney injury. Front Pharmacol 2024; 15:1328259. [PMID: 38313311 PMCID: PMC10834784 DOI: 10.3389/fphar.2024.1328259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/03/2024] [Indexed: 02/06/2024] Open
Abstract
Aim: Apolipoprotein M (apoM) is mainly expressed in liver and in proximal tubular epithelial cells in the kidney. In plasma, apoM associates with HDL particles via a retained signal peptide and carries sphingosine-1-phosphate (S1P), a small bioactive lipid. ApoM is undetectable in urine from healthy individuals but lack of megalin receptors in proximal tubuli cells induces loss of apoM into the urine. Besides this, very little is known about kidney-derived apoM. The aim of this study was to address the role of apoM in kidney biology and in acute kidney injury. Methods: A novel kidney-specific human apoM transgenic mouse model (RPTEC-hapoMTG) was generated and subjected to either cisplatin or ischemia/reperfusion injury. Further, a stable transfection of HK-2 cells overexpressing human apoM (HK-2-hapoMTG) was developed to study the pattern of apoM secretion in proximal tubuli cells. Results: Human apoM was present in plasma from RPTEC-hapoMTG mice (mean 0.18 μM), with a significant increase in plasma S1P levels. In vitro apoM was secreted to both the apical (urine) and basolateral (blood) compartment from proximal tubular epithelial cells. However, no differences in kidney injury score was seen between RPTEC-hapoMTG and wild type (WT) mice upon kidney injury. Further, gene expression of inflammatory markers (i.e., IL6, MCP-1) was similar upon ischemia/reperfusion injury. Conclusion: Our study suggests that kidney-derived apoM is secreted to plasma, supporting a role for apoM in sequestering molecules from excretion in urine. However, overexpression of human apoM in the kidney did not protect against acute kidney injury.
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Affiliation(s)
- Line S. Bisgaard
- Department of Clinical Biochemistry, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pernille M. Christensen
- Department of Clinical Biochemistry, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jeongah Oh
- Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Federico Torta
- Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore, Singapore
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | | | - Lars Bo Nielsen
- The Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Christina Christoffersen
- Department of Clinical Biochemistry, Copenhagen University Hospital—Rigshospitalet, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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Maharaj AV. Familial Glucocorticoid Deficiency: the changing landscape of an eponymous syndrome. Front Endocrinol (Lausanne) 2023; 14:1268345. [PMID: 38189052 PMCID: PMC10771341 DOI: 10.3389/fendo.2023.1268345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/28/2023] [Indexed: 01/09/2024] Open
Abstract
Familial Glucocorticoid Deficiency encompasses a broad spectrum of monogenic recessive disorders that theoretically solely abrogate cortisol biosynthesis. In reality, delineating clear genotype-phenotype correlations in this disorder is made complicated by marked phenotypic heterogeneity even within kindreds harbouring identical variants. Phenotypes range from isolated glucocorticoid insufficiency to cortisol deficiency plus a variety of superimposed features including salt-wasting and hypoaldosteronism, primary hypothyroidism, hypogonadism and growth defects. Furthermore, mutation type, domain topology and perceived enzyme activity do not always predict disease severity. Given the high burden of disease and implications of a positive diagnosis, genetic testing is crucial in the management of patients warranting detailed delineation of genomic variants including viable functional studies.
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Affiliation(s)
- Avinaash V. Maharaj
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London (QMUL), London, United Kingdom
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3
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Roa-Bautista A, Sohail M, Wakeling E, Gilmour KC, Davis M, Gait A, Lucchini G, Cox D, Elfeky R, Kusters M. Combined novel homozygous variants in both SGPL1 and STAT 1 presenting with severe combined immune deficiency: case report and literature review. Front Immunol 2023; 14:1186575. [PMID: 37377976 PMCID: PMC10291229 DOI: 10.3389/fimmu.2023.1186575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023] Open
Abstract
Background Sphingosine phosphate lyase insufficiency syndrome (SPLIS) is associated with biallelic variants in SGPL1, comprising a multisystemic disease characterized by steroid resistant nephrotic syndrome, primary adrenal insufficiency, neurological problems, skin abnormalities and immunodeficiency in described cases. Signal transducer and activator of transcription 1 (STAT1) plays an important role in orchestrating an appropriate immune response through JAK-STAT pathway. Biallelic STAT1 loss of function (LOF) variants lead to STAT1 deficiency with a severe phenotype of immunodeficiency with increased frequency of infections and poor outcome if untreated. Case presentation We report novel homozygous SGPL1 and STAT1 variants in a newborn of Gambian ethnicity with clinical features of SPLIS and severe combined immunodeficiency. The patient presented early in life with nephrotic syndrome, severe respiratory infection requiring ventilation, ichthyosis, and hearing loss, with T-cell lymphopenia. The combination of these two conditions led to severe combined immunodeficiency with inability to clear respiratory tract infections of viral, fungal, and bacterial nature, as well as severe nephrotic syndrome. The child sadly died at 6 weeks of age despite targeted treatments. Conclusion We report the finding of two novel, homozygous variants in SGPL1 and STAT1 in a patient with a severe clinical phenotype and fatal outcome early in life. This case highlights the importance of completing the primary immunodeficiency genetic panel in full to avoid missing a second diagnosis in other patients presenting with similar severe clinical phenotype early in life. For SPLIS no curative treatment is available and more research is needed to investigate different treatment modalities. Hematopoietic stem cell transplantation (HSCT) shows promising results in patients with autosomal recessive STAT1 deficiency. For this patient's family, identification of the dual diagnosis has important implications for future family planning. In addition, future siblings with the familial STAT1 variant can be offered curative treatment with HSCT.
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Affiliation(s)
- Adriel Roa-Bautista
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
- Immunology Unit, Marqués De Valdecilla University Hospital, Santander, Spain
| | - Mahreen Sohail
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Emma Wakeling
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
- North East Thames Regional Genetic Service, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Kimberly C. Gilmour
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Mark Davis
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Anthony Gait
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
- North East Thames Regional Genetic Service, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Giovanna Lucchini
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
- Great Ormond Street (GOS) Hospital for Children National Health Service (NHS) Foundation Trust, University College London Great Ormond Street (GOS) Institute of Child Health, and National Institute fot Health and Care Research (NIHR), Great Ormond Street Hospital (GOSH), Biomedical Research Centre (BRC), London, United Kingdom
| | - David Cox
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Reem Elfeky
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
- Great Ormond Street (GOS) Hospital for Children National Health Service (NHS) Foundation Trust, University College London Great Ormond Street (GOS) Institute of Child Health, and National Institute fot Health and Care Research (NIHR), Great Ormond Street Hospital (GOSH), Biomedical Research Centre (BRC), London, United Kingdom
| | - Maaike Kusters
- Paediatric Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
- Great Ormond Street (GOS) Hospital for Children National Health Service (NHS) Foundation Trust, University College London Great Ormond Street (GOS) Institute of Child Health, and National Institute fot Health and Care Research (NIHR), Great Ormond Street Hospital (GOSH), Biomedical Research Centre (BRC), London, United Kingdom
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4
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Chung HL, Ye Q, Park YJ, Zuo Z, Mok JW, Kanca O, Tattikota SG, Lu S, Perrimon N, Lee HK, Bellen HJ. Very-long-chain fatty acids induce glial-derived sphingosine-1-phosphate synthesis, secretion, and neuroinflammation. Cell Metab 2023; 35:855-874.e5. [PMID: 37084732 PMCID: PMC10160010 DOI: 10.1016/j.cmet.2023.03.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 01/10/2023] [Accepted: 03/29/2023] [Indexed: 04/23/2023]
Abstract
VLCFAs (very-long-chain fatty acids) are the most abundant fatty acids in myelin. Hence, during demyelination or aging, glia are exposed to higher levels of VLCFA than normal. We report that glia convert these VLCFA into sphingosine-1-phosphate (S1P) via a glial-specific S1P pathway. Excess S1P causes neuroinflammation, NF-κB activation, and macrophage infiltration into the CNS. Suppressing the function of S1P in fly glia or neurons, or administration of Fingolimod, an S1P receptor antagonist, strongly attenuates the phenotypes caused by excess VLCFAs. In contrast, elevating the VLCFA levels in glia and immune cells exacerbates these phenotypes. Elevated VLCFA and S1P are also toxic in vertebrates based on a mouse model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). Indeed, reducing VLCFA with bezafibrate ameliorates the phenotypes. Moreover, simultaneous use of bezafibrate and fingolimod synergizes to improve EAE, suggesting that lowering VLCFA and S1P is a treatment avenue for MS.
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Affiliation(s)
- Hyung-Lok Chung
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Qi Ye
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Department of Pediatrics, Section of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ye-Jin Park
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jung-Wan Mok
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | | | - Shenzhao Lu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Nobert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA; Howard Hughes Medical Institute and Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Hyun Kyoung Lee
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Department of Pediatrics, Section of Neurology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA.
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5
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Pournasiri Z, Madani A, Nazarpack F, Sayer JA, Chavoshzadeh Z, Nili F, Tran P, Saba JD, Jamee M. Sphingosine phosphate lyase insufficiency syndrome: a systematic review. World J Pediatr 2023; 19:425-437. [PMID: 36371483 DOI: 10.1007/s12519-022-00615-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND Sphingosine-1-phosphate lyase insufficiency syndrome (SPLIS) or nephrotic syndrome type-14 is caused by biallelic mutations in SGPL1. Here, we conducted a systematic review to delineate the characteristics of SPLIS patients. METHODS A literature search was performed in PubMed, Web of Science, and Scopus databases, and eligible studies were included. For all patients, demographic, clinical, laboratory, and molecular data were collected and analyzed. RESULTS Fifty-five SPLIS patients (54.9% male, 45.1% female) were identified in 19 articles. Parental consanguinity and positive family history were reported in 70.9% and 52.7% of patients, respectively. Most patients (54.9%) primarily manifested within the first year of life, nearly half of whom survived, while all patients with a prenatal diagnosis of SPLIS (27.5%) died at a median [interquartile (IQR)] age of 2 (1.4-5.3) months (P = 0.003). The most prevalent clinical feature was endocrinopathies, including primary adrenal insufficiency (PAI) (71.2%) and hypothyroidism (32.7%). Kidney disorders (42, 80.8%) were mainly in the form of steroid-resistant nephrotic syndrome (SRNS) and progressed to end-stage kidney disease (ESKD) in 19 (36.5%) patients at a median (IQR) age of 6 (1.4-42.6) months. Among 30 different mutations in SGPL1, the most common was c.665G > A (p.Arg222Gln) in 11 (20%) patients. Twenty-six (49.1%) patients with available outcome were deceased at a median (IQR) age of 5 (1.5-30.5) months, mostly following ESKD (23%) or sepsis/septic shock (23%). CONCLUSION In patients with PAI and/or SRNS, SGPL1 should be added to diagnostic genetic panels, which can provide an earlier diagnosis of SPLIS and prevention of ESKD and other life-threatening complications.
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Affiliation(s)
- Zahra Pournasiri
- Pediatric Nephrology Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Madani
- Department of Pediatric Nephrology, Children's Medical Center, Pediatric Chronic Kidney Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Nazarpack
- Pediatric Nephrology Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - John A Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE7 7DN, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle University, Newcastle upon Tyne, NE45PL, Tyne and Wear, UK
| | - Zahra Chavoshzadeh
- Immunology and Allergy Department, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, 15514-15468, Iran
| | - Fatemeh Nili
- Department of Pathology, Imam Khomeini Complex Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Paulina Tran
- Allergy Immunology Division, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, USA
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, USA
| | - Julie D Saba
- Division of Hematology/Oncology, Department of Pediatrics, University of California, San Francisco, CA, USA
| | - Mahnaz Jamee
- Pediatric Nephrology Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Immunology and Allergy Department, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, 15514-15468, Iran.
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6
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Smith CJ, Williams JL, Hall C, Casas J, Caley MP, O'Toole EA, Prasad R, Metherell LA. Ichthyosis linked to sphingosine 1-phosphate lyase insufficiency is due to aberrant sphingolipid and calcium regulation. J Lipid Res 2023; 64:100351. [PMID: 36868360 PMCID: PMC10123262 DOI: 10.1016/j.jlr.2023.100351] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 02/15/2023] [Accepted: 02/18/2023] [Indexed: 03/05/2023] Open
Abstract
Sphingosine 1-phosphate lyase (SGPL1) insufficiency (SPLIS) is a syndrome which presents with adrenal insufficiency, steroid-resistant nephrotic syndrome, hypothyroidism, neurological disease, and ichthyosis. Where a skin phenotype is reported, 94% had abnormalities such as ichthyosis, acanthosis, and hyperpigmentation. To elucidate the disease mechanism and the role SGPL1 plays in the skin barrier we established clustered regularly interspaced short palindromic repeats-Cas9 SGPL1 KO and a lentiviral-induced SGPL1 overexpression (OE) in telomerase reverse-transcriptase immortalised human keratinocytes (N/TERT-1) and thereafter organotypic skin equivalents. Loss of SGPL1 caused an accumulation of S1P, sphingosine, and ceramides, while its overexpression caused a reduction of these species. RNAseq analysis showed perturbations in sphingolipid pathway genes, particularly in SGPL1_KO, and our gene set enrichment analysis revealed polar opposite differential gene expression between SGPL1_KO and _OE in keratinocyte differentiation and Ca2+ signaling genesets. SGPL1_KO upregulated differentiation markers, while SGPL1_OE upregulated basal and proliferative markers. The advanced differentiation of SGPL1_KO was confirmed by 3D organotypic models that also presented with a thickened and retained stratum corneum and a breakdown of E-cadherin junctions. We conclude that SPLIS associated ichthyosis is a multifaceted disease caused possibly by sphingolipid imbalance and excessive S1P signaling, leading to increased differentiation and an imbalance of the lipid lamellae throughout the epidermis.
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Affiliation(s)
- Christopher J Smith
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom.
| | - Jack L Williams
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Charlotte Hall
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Josefina Casas
- Research Unit on BioActive Molecules (RUBAM), Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain; Biomedical Research Centre (CIBEREHD), ISCIII, Madrid, Spain
| | - Matthew P Caley
- Cell Biology and Cutaneous Research, Blizard Institute, Queen Mary University of London, London, United Kingdom
| | - Edel A O'Toole
- Cell Biology and Cutaneous Research, Blizard Institute, Queen Mary University of London, London, United Kingdom
| | - Rathi Prasad
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Louise A Metherell
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
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7
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Wieczorek I, Strosznajder RP. Recent Insight into the Role of Sphingosine-1-Phosphate Lyase in Neurodegeneration. Int J Mol Sci 2023; 24:ijms24076180. [PMID: 37047151 PMCID: PMC10093903 DOI: 10.3390/ijms24076180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 04/14/2023] Open
Abstract
Sphingosine-1-phosphate lyase (SPL) is a pyridoxal 5'-phosphate-dependent enzyme involved in the irreversible degradation of sphingosine-1-phosphate (S1P)-a bioactive sphingolipid that modulates a broad range of biological processes (cell proliferation, migration, differentiation and survival; mitochondrial functioning; and gene expression). Although SPL activity leads to a decrease in the available pool of S1P in the cell, at the same time, hexadecenal and phosphoethanolamine, compounds with potential biological activity, are generated. The increased expression and/or activity of SPL, and hence the imbalance between S1P and the end products of its cleavage, were demonstrated in several pathological states. On the other hand, loss-of-function mutations in the SPL encoding gene are a cause of severe developmental impairments. Recently, special attention has been paid to neurodegenerative diseases as the most common pathologies of the nervous system. This review summarizes the current findings concerning the role of SPL in the nervous system with an emphasis on neurodegeneration. Moreover, it briefly discusses pharmacological compounds directed to inhibit its activity.
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Affiliation(s)
- Iga Wieczorek
- Laboratory of Preclinical Research and Environmental Agents, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 St., 02-106 Warsaw, Poland
| | - Robert Piotr Strosznajder
- Laboratory of Preclinical Research and Environmental Agents, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 St., 02-106 Warsaw, Poland
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8
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Tastemel Ozturk T, Canpolat N, Saygili S, Bayrakci US, Soylemezoglu O, Ozaltin F, Topaloglu R. A rare cause of nephrotic syndrome-sphingosine-1-phosphate lyase (SGPL1) deficiency: 6 cases and a review of the literature. Pediatr Nephrol 2023; 38:711-719. [PMID: 35748945 DOI: 10.1007/s00467-022-05656-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 01/19/2023]
Abstract
BACKGROUND Recently, recessive mutations in SGPL1 (sphingosine-1-phosphate lyase), which encodes the final enzyme of sphingolipid metabolism, have been reported to cause steroid-resistant nephrotic syndrome, adrenal insufficiency, and many other organ/system involvements. We aimed to determine the clinical and genetic characteristics, and outcomes in patients with SGPL1 mutations. METHODS The study included 6 patients with bi-allelic SGPL1 mutation. Clinical, genetic, and laboratory characteristics, and outcomes of the patients were evaluated retrospectively. We also reviewed previously reported patients with SGPL1 mutations and compared them to the presented patients. RESULTS The median age at kidney presentation was 5 months. Four patients (67%) were diagnosed before age 1 year. Kidney biopsy showed focal segmental glomerulosclerosis in 2 patients and diffuse mesangial sclerosis in one patient. Steroids were given to 3 patients, but they did not respond. All 6 patients progressed to chronic kidney disease; 5 required kidney replacement therapy (KRT) at a median age of 6 months. Deceased kidney transplantation was performed in one patient. All 6 patients had adrenal insufficiency, of which 5 were diagnosed at age < 6 months. Three patients had hypothyroidism, 2 had ichthyosis, 4 had immunodeficiency, 5 had neurological findings, and 2 had genitourinary system anomalies. Four patients died at a median age of 30.5 months. Two patients are being followed up with KRT. One patient had a novel mutation. CONCLUSIONS Patients with SGPL1 mutations have a poor prognosis, and many types of extrarenal organ/system involvement beyond adrenal insufficiency can be seen. Genetic diagnosis of such patients is important for treatment, genetic counseling, and screening for comorbid conditions. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Tugba Tastemel Ozturk
- Department of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, Sihhiye, 06100, Ankara, Turkey.
| | - Nur Canpolat
- Department of Pediatric Nephrology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Seha Saygili
- Department of Pediatric Nephrology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Umut Selda Bayrakci
- Department of Pediatric Nephrology, Faculty of Medicine, Ankara City Hospital, Ankara Yildirim Beyazit University, Ankara, Turkey
| | - Oguz Soylemezoglu
- Department of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Fatih Ozaltin
- Department of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
- Nephrogenetics Laboratory, Department of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Rezan Topaloglu
- Department of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
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9
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Imeri F, Stepanovska Tanturovska B, Manaila R, Pavenstädt H, Pfeilschifter J, Huwiler A. Loss of S1P Lyase Expression in Human Podocytes Causes a Reduction in Nephrin Expression That Involves PKCδ Activation. Int J Mol Sci 2023; 24:3267. [PMID: 36834691 PMCID: PMC9965238 DOI: 10.3390/ijms24043267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/30/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Sphingosine 1-phosphate (S1P) lyase (SPL, Sgpl1) is an ER-associated enzyme that irreversibly degrades the bioactive lipid, S1P, and thereby regulates multiple cellular functions attributed to S1P. Biallelic mutations in the human Sglp1 gene lead to a severe form of a particular steroid-resistant nephrotic syndrome, suggesting that the SPL is critically involved in maintaining the glomerular ultrafiltration barrier, which is mainly built by glomerular podocytes. In this study, we have investigated the molecular effects of SPL knockdown (kd) in human podocytes to better understand the mechanism underlying nephrotic syndrome in patients. A stable SPL-kd cell line of human podocytes was generated by the lentiviral shRNA transduction method and was characterized for reduced SPL mRNA and protein levels and increased S1P levels. This cell line was further studied for changes in those podocyte-specific proteins that are known to regulate the ultrafiltration barrier. We show here that SPL-kd leads to the downregulation of the nephrin protein and mRNA expression, as well as the Wilms tumor suppressor gene 1 (WT1), which is a key transcription factor regulating nephrin expression. Mechanistically, SPL-kd resulted in increased total cellular protein kinase C (PKC) activity, while the stable downregulation of PKCδ revealed increased nephrin expression. Furthermore, the pro-inflammatory cytokine, interleukin 6 (IL-6), also reduced WT1 and nephrin expression. In addition, IL-6 caused increased PKCδ Thr505 phosphorylation, suggesting enzyme activation. Altogether, these data demonstrate that nephrin is a critical factor downregulated by the loss of SPL, which may directly cause podocyte foot process effacement as observed in mice and humans, leading to albuminuria, a hallmark of nephrotic syndrome. Furthermore, our in vitro data suggest that PKCδ could represent a new possible pharmacological target for the treatment of a nephrotic syndrome induced by SPL mutations.
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Affiliation(s)
- Faik Imeri
- Institute of Pharmacology, Inselspital, INO-F, University of Bern, CH-3010 Bern, Switzerland
| | | | - Roxana Manaila
- Institute of Pharmacology, Inselspital, INO-F, University of Bern, CH-3010 Bern, Switzerland
| | - Hermann Pavenstädt
- Medizinische Klinik D, University Hospital Münster, D-48149 Münster, Germany
| | - Josef Pfeilschifter
- Pharmazentrum Frankfurt/ZAFES, University Hospital, Goethe University Frankfurt am Main, Theodor-Stern Kai 7, D-60590 Frankfurt am Main, Germany
| | - Andrea Huwiler
- Institute of Pharmacology, Inselspital, INO-F, University of Bern, CH-3010 Bern, Switzerland
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10
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Abstract
The adrenal cortex undergoes multiple structural and functional rearrangements to satisfy the systemic needs for steroids during fetal life, postnatal development, and adulthood. A fully functional adrenal cortex relies on the proper subdivision in regions or 'zones' with distinct but interconnected functions, which evolve from the early embryonic stages to adulthood, and rely on a fine-tuned gene network. In particular, the steroidogenic activity of the fetal adrenal is instrumental in maintaining normal fetal development and growth. Here, we review and discuss the most recent advances in our understanding of embryonic and fetal adrenal development, including the known causes for adrenal dys-/agenesis, and the steroidogenic pathways that link the fetal adrenal with the hormone system of the mother through the fetal-placental unit. Finally, we discuss what we think are the major open questions in the field, including, among others, the impact of osteocalcin, thyroid hormone, and other hormone systems on adrenal development and function, and the reliability of rodents as models of adrenal pathophysiology.
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Affiliation(s)
- Emanuele Pignatti
- Department of Pediatrics, Division of Endocrinology, Diabetology and Metabolism, University Hospital Inselspital, University of Bern, 3010, Bern, Switzerland.
- Department for BioMedical Research, University Hospital Inselspital, University of Bern, 3010, Bern, Switzerland.
| | - Therina du Toit
- Department for BioMedical Research, University Hospital Inselspital, University of Bern, 3010, Bern, Switzerland.
| | - Christa E Flück
- Department of Pediatrics, Division of Endocrinology, Diabetology and Metabolism, University Hospital Inselspital, University of Bern, 3010, Bern, Switzerland
- Department for BioMedical Research, University Hospital Inselspital, University of Bern, 3010, Bern, Switzerland
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11
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Yang S, He Y, Zhou J, Yuan H, Qiu L. Steroid-resistant nephrotic syndrome associated with certain SGPL1 variants in a family: Case report and literature review. Front Pediatr 2023; 11:1079758. [PMID: 36873630 PMCID: PMC9978203 DOI: 10.3389/fped.2023.1079758] [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: 10/25/2022] [Accepted: 01/16/2023] [Indexed: 02/18/2023] Open
Abstract
OBJECTIVES Steroid-resistant nephrotic syndrome (SRNS) is a clinical syndrome characterized by the lack of response to standard steroid therapy, usually progressing to end-stage renal disease. We reported two cases of female identical twins with SRNS caused by SGPL1 variants in one family, reviewed the relevant literature, and summarized their clinical phenotypes, pathological types, and genotypic characteristics. METHODS Two cases of nephrotic syndrome caused by SGPL1 variants were admitted to Tongji Hospital, affiliated with Tongji Medical College of Huazhong University of Science and Technology. Their clinical data were retrospectively collected, and the peripheral blood genomic DNA was captured and sequenced by whole exome sequencing. Related literature published in PubMed, CNKI, and Wan fang databases was reviewed. RESULTS We described two Chinese identical twin girls with isolated SRNS due to compound heterozygous variants in the SGPL1 (intron4 c.261 + 1G > A and intron12 c.1298 + 6T > C). The patients were followed up for 60.0 months and 53.0 months, respectively, having no extra-renal manifestations. They all died due to renal failure. A total of 31 children with SGPL1 variants causing nephrotic syndrome (including the reported two cases) were identified through a literature review. CONCLUSIONS These two female identical twins were the first reported cases of isolated SRNS caused by SGPL1 variants. Almost all homozygous and compound heterozygous variants of SGPL1 had extra-renal manifestations, but compound heterozygous variants in the intron of SGPL1 may have no obvious extra-renal manifestations. Additionally, a negative genetic testing result does not completely rule out genetic SRNS because the Human Gene Mutation Database or ClinVar is constantly being updated.
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Affiliation(s)
- Siying Yang
- The Nephrology Division of Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yonghua He
- The Nephrology Division of Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jianhua Zhou
- The Nephrology Division of Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huiqing Yuan
- The Nephrology Division of Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Liru Qiu
- The Nephrology Division of Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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12
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Ron HA, Scobell R, Strong A, Salazar EG, Ganetzky R. Congenital adrenal calcifications as the first clinical indication of sphingosine lyase insufficiency syndrome: A case report and review of the literature. Am J Med Genet A 2022; 188:3312-3317. [PMID: 35972040 PMCID: PMC9548492 DOI: 10.1002/ajmg.a.62956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/21/2022] [Accepted: 07/28/2022] [Indexed: 01/31/2023]
Abstract
Sphingosine Lyase Insufficiency Syndrome (SPLIS) or SGPL1 Deficiency is a newly described entity that is characterized by steroid-resistant nephrotic syndrome, primary adrenal insufficiency, lymphopenia, ichthyosis, and/or endocrine and neurologic abnormalities. The earliest identification of SGPL1 pathogenic variants in association with this syndrome was reported in 2017. Since then, at least 36 patients have been reported with this pediatric syndrome. Here, we report a new patient with SPLIS who had a prenatal finding of adrenal calcifications, congenital nephrotic syndrome, and abnormal newborn screening concerning for Severe Combined Immunodeficiency. We conclude that SPLIS is a clinically recognizable condition with prenatal onset. This case should increase awareness of SPLIS in the differential diagnosis for adrenal calcifications. We present a case on the severe end of the clinical spectrum of SPLIS, and a review of the literature.
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Affiliation(s)
- Hayley A. Ron
- Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Rebecca Scobell
- Division of Nephrology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Amy Strong
- Division of Nephrology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Elizabeth G. Salazar
- Division of Neonatalogy, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Rebecca Ganetzky
- Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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13
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Atreya KB, Saba JD. Neurological Consequences of Sphingosine Phosphate Lyase Insufficiency. Front Cell Neurosci 2022; 16:938693. [PMID: 36187293 PMCID: PMC9519528 DOI: 10.3389/fncel.2022.938693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
In 2017, an inborn error of metabolism caused by recessive mutations in SGPL1 was discovered. The disease features steroid-resistant nephrotic syndrome, adrenal insufficiency, and neurological defects. The latter can include sensorineural hearing loss, cranial nerve defects, peripheral neuropathy, abnormal brain development, seizures and/or neurodegeneration. SGPL1 encodes the pyridoxal-5’-phosphate (PLP) dependent enzyme sphingosine phosphate lyase (SPL), and the condition is now referred to as SPL insufficiency syndrome (SPLIS). SPL catalyzes the final step in the degradative pathway of sphingolipids in which the bioactive sphingolipid sphingosine-1-phosphate (S1P) is irreversibly degraded to a long chain aldehyde and phosphoethanolamine (PE). SPL guards the only exit point for sphingolipid metabolism, and its inactivation leads to accumulation of various types of sphingolipids which have biophysical roles in plasma membrane rafts and myelin, and signaling roles in cell cycle progression, vesicular trafficking, cell migration, and programmed cell death. In addition, the products of the SPL reaction have biological functions including regulation of autophagic flux, which is important in axonal and neuronal integrity. In this review, the neurological manifestations of SPLIS will be described, and insights regarding the neurological consequences of SPL insufficiency from the study of brain-specific SPL knockout mice and Drosophila SPL mutants will be summarized.
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Affiliation(s)
- Krishan B. Atreya
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Julie D. Saba
- Department of Pediatrics, School of Medicine, University of California, San Francisco, San Francisco, CA, United States
- *Correspondence: Julie D. Saba
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14
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Maharaj A, Kwong R, Williams J, Smith C, Storr H, Krone R, Braslavsky D, Clemente M, Ram N, Banerjee I, Çetinkaya S, Buonocore F, Güran T, Achermann JC, Metherell L, Prasad R. A retrospective analysis of endocrine disease in sphingosine-1-phosphate lyase insufficiency: case series and literature review. Endocr Connect 2022; 11:e220250. [PMID: 35904228 PMCID: PMC9346324 DOI: 10.1530/ec-22-0250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 06/28/2022] [Indexed: 11/14/2022]
Abstract
Sphingosine-1-phosphate lyase (SGPL1) insufficiency syndrome (SPLIS) is an autosomal recessive multi-system disorder, which mainly incorporates steroid-resistant nephrotic syndrome and primary adrenal insufficiency. Other variable endocrine manifestations are described. In this study, we aimed to comprehensively annotate the endocrinopathies associated with pathogenic SGPL1 variants and assess for genotype-phenotype correlations by retrospectively reviewing the reports of endocrine disease within our patient cohort and all published cases in the wider literature up to February 2022. Glucocorticoid insufficiency in early childhood is the most common endocrine manifestation affecting 64% of the 50 patients reported with SPLIS, and a third of these individuals have additional mineralocorticoid deficiency. While most individuals also have nephrotic syndrome, SGPL1 variants also account for isolated adrenal insufficiency at presentation. Primary gonadal insufficiency, manifesting with microphallus and cryptorchidism, is reported in less than one-third of affected boys, all with concomitant adrenal disease. Mild primary hypothyroidism affects approximately a third of patients. There is paucity of data on the impact of SGPL1 deficiency on growth, and pubertal development, limited by the early and high mortality rate (approximately 50%). There is no clear genotype-phenotype correlation overall in the syndrome, with variable disease penetrance within individual kindreds. However, with regards to endocrine phenotype, the most prevalent disease variant p.R222Q (affecting 22%) is most consistently associated with isolated glucocorticoid deficiency. To conclude, SPLIS is associated with significant multiple endocrine disorders. While endocrinopathy in the syndrome generally presents in infancy, late-onset disease also occurs. Screening for these is therefore warranted both at diagnosis and through follow-up.
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Affiliation(s)
- Avinaash Maharaj
- Centre for Endocrinology, John Vane Science Centre, Queen Mary University of London, London, UK
| | - Ruth Kwong
- Centre for Endocrinology, John Vane Science Centre, Queen Mary University of London, London, UK
| | - Jack Williams
- Centre for Endocrinology, John Vane Science Centre, Queen Mary University of London, London, UK
| | - Christopher Smith
- Centre for Endocrinology, John Vane Science Centre, Queen Mary University of London, London, UK
| | - Helen Storr
- Centre for Endocrinology, John Vane Science Centre, Queen Mary University of London, London, UK
| | - Ruth Krone
- Birmingham Children’s Hospital, Birmingham, UK
| | - Debora Braslavsky
- Centro de Investigaciones Endocrinológicas ‘Dr. Cesar Bergadá’ (CEDIE) – CONICET – FEI – División de Endocrinología, Hospital de Niños ‘Ricardo Gutiérrez’, Buenos Aires, Argentina
| | - Maria Clemente
- Paediatric Endocrinology, Growth and Development Research Unit, Vall d’Hebron Research Institute (VHIR), Hospital Vall d’Hebron, CIBERER, Instituto de Salud Carlos III, Barcelona, Spain
| | - Nanik Ram
- Department of Endocrinology, The Aga Khan University Hospital, Karachi, Pakistan
| | - Indraneel Banerjee
- Department of Paediatric Endocrinology, Royal Manchester Children’s Hospital, Manchester, UK
| | - Semra Çetinkaya
- Health Sciences University, Dr. Sami Ulus Obstetrics and Gynaecology, Children’s Health and Disease Education and Research Hospital, Ankara, Turkey
| | - Federica Buonocore
- Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Tülay Güran
- Department of Paediatric Endocrinology and Diabetes, Marmara University, School of Medicine, Istanbul, Turkey
| | - John C Achermann
- Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Louise Metherell
- Centre for Endocrinology, John Vane Science Centre, Queen Mary University of London, London, UK
| | - Rathi Prasad
- Centre for Endocrinology, John Vane Science Centre, Queen Mary University of London, London, UK
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15
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Maharaj A, Güran T, Buonocore F, Achermann JC, Metherell L, Prasad R, Çetinkaya S. Insights From Long-term Follow-up of a Girl With Adrenal Insufficiency and Sphingosine-1-Phosphate Lyase Deficiency. J Endocr Soc 2022; 6:bvac020. [PMID: 35308304 PMCID: PMC8926068 DOI: 10.1210/jendso/bvac020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Indexed: 11/21/2022] Open
Abstract
Introduction Sphingosine-1-phosphate lyase (SGPL1) insufficiency syndrome (SPLIS) is a multisystemic disorder which, in the main, incorporates steroid-resistant nephrotic syndrome and primary adrenal insufficiency (PAI). Case Presentation We present a young girl with a novel homozygous variant in SGPL1, p.D350G, with PAI in the absence of nephrotic syndrome. In the course of 15 years of follow-up she has further developed primary hypothyroidism and while she has progressed through puberty appropriately, ovarian calcifications were noted on imaging. The p.D350G variant results in reduced protein expression of SGPL1. We demonstrate that CRISPR engineered knockout of SGPL1 in human adrenocortical (H295R) cells abrogates cortisol production. Furthermore, while wild-type SGPL1 is able to rescue cortisol production in this in vitro model of adrenal disease, this is not observed with the p.D350G mutant. Conclusion SGPL1 deficiency should be considered in the differential diagnosis of PAI with close attention paid to evolving disease on follow-up.
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Affiliation(s)
- Avinaash Maharaj
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Tülay Güran
- Marmara University, School of Medicine, Department of Paediatric Endocrinology and Diabetes, Istanbul, Turkey
| | - Federica Buonocore
- Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - John C Achermann
- Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Louise Metherell
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Rathi Prasad
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Semra Çetinkaya
- Health Sciences University, Dr. Sami Ulus Obstetrics and Gynecology, Children’s Health and Disease Education and Research Hospital, Ankara, Turkey
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16
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Spaulding SC, Bollag WB. The role of lipid second messengers in aldosterone synthesis and secretion. J Lipid Res 2022; 63:100191. [PMID: 35278411 PMCID: PMC9020094 DOI: 10.1016/j.jlr.2022.100191] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 11/23/2022] Open
Abstract
Second messengers are small rapidly diffusing molecules or ions that relay signals between receptors and effector proteins to produce a physiological effect. Lipid messengers constitute one of the four major classes of second messengers. The hydrolysis of two main classes of lipids, glycerophospholipids and sphingolipids, generate parallel profiles of lipid second messengers: phosphatidic acid (PA), diacylglycerol (DAG), and lysophosphatidic acid versus ceramide, ceramide-1-phosphate, sphingosine, and sphingosine-1-phosphate, respectively. In this review, we examine the mechanisms by which these lipid second messengers modulate aldosterone production at multiple levels. Aldosterone is a mineralocorticoid hormone responsible for maintaining fluid volume, electrolyte balance, and blood pressure homeostasis. Primary aldosteronism is a frequent endocrine cause of secondary hypertension. A thorough understanding of the signaling events regulating aldosterone biosynthesis may lead to the identification of novel therapeutic targets. The cumulative evidence in this literature emphasizes the critical roles of PA, DAG, and sphingolipid metabolites in aldosterone synthesis and secretion. However, it also highlights the gaps in our knowledge, such as the preference for phospholipase D-generated PA or DAG, as well as the need for further investigation to elucidate the precise mechanisms by which these lipid second messengers regulate optimal aldosterone production.
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Affiliation(s)
- Shinjini C Spaulding
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Wendy B Bollag
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA; Research Department, Charlie Norwood VA Medical Center, Augusta, GA, USA.
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17
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Mathew G, Yasmeen MS, Deepthi RV, Swain M, Vattam A, Shah MA, Agarwal I. Infantile nephrotic syndrome, immunodeficiency and adrenal insufficiency-a rare cause: Answers. Pediatr Nephrol 2022; 37:817-819. [PMID: 34999987 DOI: 10.1007/s00467-021-05377-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 11/01/2021] [Indexed: 10/19/2022]
Affiliation(s)
- Georgie Mathew
- Division of Pediatric Nephrology, Christian Medical College, Vellore, India.
| | - M S Yasmeen
- Little Star Children's Hospital, Hyderabad, India
| | - R V Deepthi
- Division of Pediatric Nephrology, Christian Medical College, Vellore, India
| | - Meenakshi Swain
- Department of Histopathology, Apollo Health City, Hyderabad, India
| | | | - Mehul A Shah
- Little Star Children's Hospital, Hyderabad, India
| | - Indira Agarwal
- Division of Pediatric Nephrology, Christian Medical College, Vellore, India
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18
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Wolf JJ, Saba JD, Hahm B. Analyzing Opposing Interactions Between Sphingosine 1-Phosphate Lyase and Influenza A Virus. DNA Cell Biol 2022; 41:331-335. [PMID: 35325556 PMCID: PMC9063141 DOI: 10.1089/dna.2022.0071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Sphingosine 1-phosphate lyase (SPL) is a critical component of sphingosine 1-phosphate (S1P) metabolism. SPL has been associated with several crucial cellular functions due to its role in S1P metabolism, but its role in viral infections is poorly understood. Studies show that SPL has an antiviral function against influenza A virus (IAV) by interacting with IKKɛ, promoting the type I interferon (IFN) innate immune response to IAV infection. However, a more recent study has revealed that IAV NS1 protein hampers this by triggering ubiquitination and subsequent degradation of SPL, which reduces the type I IFN innate immune response. In this study, we describe SPL, the type I IFN response, and known interactions between SPL and IAV.
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Affiliation(s)
- Jennifer J. Wolf
- Department of Surgery and Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, USA
| | - Julie D. Saba
- Department of Pediatrics, University of California, San Francisco, California, USA
| | - Bumsuk Hahm
- Department of Surgery and Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, USA
- Address correspondence to: Bumsuk Hahm, PhD, Departments of Surgery and Molecular Microbiology and Immunology, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
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19
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Bisgaard LS, Christoffersen C. The apoM/S1P Complex-A Mediator in Kidney Biology and Disease? Front Med (Lausanne) 2021; 8:754490. [PMID: 34722589 PMCID: PMC8553247 DOI: 10.3389/fmed.2021.754490] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/16/2021] [Indexed: 12/18/2022] Open
Abstract
Kidney disease affects more than 10% of the population, can be both acute and chronic, and is linked to other diseases such as cardiovascular disease, diabetes, and sepsis. Despite the detrimental consequences for patients, no good treatment options directly targeting the kidney are available. Thus, a better understanding of the pathology and new treatment modalities are required. Accumulating evidence suggests that the apolipoprotein M/sphingosine-1-phosphate (apoM/S1P) axis is a likely drug target, but significant gaps in our knowledge remain. In this review, we present what has so far been elucidated about the role of apoM in normal kidney biology and describe how changes in the apoM/S1P axis are thought to affect the development of kidney disease. ApoM is primarily produced in the liver and kidneys. From the liver, apoM is secreted into circulation, where it is attached to lipoproteins (primarily HDL). Importantly, apoM is a carrier of the bioactive lipid S1P. S1P acts by binding to five different receptors. Together, apoM/S1P plays a role in several biological mechanisms, such as inflammation, endothelial cell permeability, and lipid turnover. In the kidney, apoM is primarily expressed in the proximal tubular cells. S1P can be produced locally in the kidney, and several of the five S1P receptors are present in the kidney. The functional role of kidney-derived apoM as well as plasma-derived apoM is far from elucidated and will be discussed based on both experimental and clinical studies. In summary, the current studies provide evidence that support a role for the apoM/S1P axis in kidney disease; however, additional pre-clinical and clinical studies are needed to reveal the mechanisms and target potential in the treatment of patients.
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Affiliation(s)
- Line S Bisgaard
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina Christoffersen
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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20
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Saba JD, Keller N, Wang JY, Tang F, Slavin A, Shen Y. Genotype/Phenotype Interactions and First Steps Toward Targeted Therapy for Sphingosine Phosphate Lyase Insufficiency Syndrome. Cell Biochem Biophys 2021; 79:547-559. [PMID: 34133011 DOI: 10.1007/s12013-021-01013-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2021] [Indexed: 10/21/2022]
Abstract
Sphingosine-1-phosphate lyase insufficiency syndrome (SPLIS) is a rare metabolic disorder caused by a deficiency in sphingosine-1-phosphate lyase (SPL), the final enzyme in the sphingolipid degradative pathway. Inactivating mutations of SGPL1-the gene encoding SPL-lead to a deficiency of its downstream products, and buildup of sphingolipid intermediates, including its bioactive substrate, sphingosine-1-phosphate (S1P), the latter causing lymphopenia, a hallmark of the disease. Other manifestations of SPLIS include nephrotic syndrome, neuronal defects, and adrenal insufficiency, but their pathogenesis remains unknown. In this report, we describe the correlation between SGPL1 genotypes, age at diagnosis, and patient outcome. Vitamin B6 serves as a cofactor for SPL. B6 supplementation may aid some SPLIS patients by overcoming poor binding kinetics and promoting proper folding and stability of mutant SPL proteins. However, this approach remains limited to patients with a susceptible allele. Gene therapy represents a potential targeted therapy for SPLIS patients harboring B6-unresponsive missense mutations, truncations, deletions, and splice-site mutations. When Sgpl1 knockout (SPLKO) mice that model SPLIS were treated with adeno-associated virus (AAV)-mediated SGPL1 gene therapy, they showed profound improvement in survival and kidney and neurological function compared to untreated SPLKO mice. Thus, gene therapy appears promising as a universal, potentially curative treatment for SPLIS.
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Affiliation(s)
- Julie D Saba
- UCSF Department of Pediatrics, San Francisco, CA, USA.
| | - Nancy Keller
- UCSF Department of Pediatrics, San Francisco, CA, USA
| | - Jen-Yeu Wang
- UCSF Department of Pediatrics, San Francisco, CA, USA
| | - Felicia Tang
- UCSF Department of Pediatrics, San Francisco, CA, USA
| | - Avi Slavin
- UCSF Department of Pediatrics, San Francisco, CA, USA
| | - Yizhuo Shen
- UCSF Department of Pediatrics, San Francisco, CA, USA
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21
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Li G, Kidd J, Gehr TWB, Li PL. Podocyte Sphingolipid Signaling in Nephrotic Syndrome. Cell Physiol Biochem 2021; 55:13-34. [PMID: 33861526 PMCID: PMC8193717 DOI: 10.33594/000000356] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2021] [Indexed: 11/25/2022] Open
Abstract
Podocytes play a vital role in the pathogenesis of nephrotic syndrome (NS), which is clinically characterized by heavy proteinuria, hypoalbuminemia, hyperlipidemia, and peripheral edema. The pathogenesis of NS has evolved through several hypotheses ranging from immune dysregulation theory and increased glomerular permeability theory to the current concept of podocytopathy. Podocytopathy is characterized by dysfunction or depletion of podocytes, which may be caused by unknown permeability factor, genetic disorders, drugs, infections, systemic disorders, and hyperfiltration. Over the last two decades, numerous studies have been done to explore the molecular mechanisms of podocyte injuries or NS and to develop the novel therapeutic strategies targeting podocytopathy for treatment of NS. Recent studies have shown that normal sphingolipid metabolism is essential for structural and functional integrity of podocytes. As a basic component of the plasma membrane, sphingolipids not only support the assembly of signaling molecules and interaction of receptors and effectors, but also mediate various cellular activities, such as apoptosis, proliferation, stress responses, necrosis, inflammation, autophagy, senescence, and differentiation. This review briefly summarizes current evidence demonstrating the regulation of sphingolipid metabolism in podocytes and the canonical or noncanonical roles of podocyte sphingolipid signaling in the pathogenesis of NS and associated therapeutic strategies.
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Affiliation(s)
- Guangbi Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Jason Kidd
- Division of Nephrology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Todd W B Gehr
- Division of Nephrology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Pin-Lan Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA,
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22
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Sgpl1 deletion elevates S1P levels, contributing to NPR2 inactivity and p21 expression that block germ cell development. Cell Death Dis 2021; 12:574. [PMID: 34083520 PMCID: PMC8175456 DOI: 10.1038/s41419-021-03848-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 11/20/2022]
Abstract
Sphingosine phosphate lyase 1 (SGPL1) is a highly conserved enzyme that irreversibly degrades sphingosine-1-phosphate (S1P). Sgpl1-knockout mice fail to develop germ cells, resulting in infertility. However, the molecular mechanism remains unclear. The results of the present study showed that SGPL1 was expressed mainly in granulosa cells, Leydig cells, spermatocytes, and round spermatids. Sgpl1 deletion led to S1P accumulation in the gonads. In the ovary, S1P decreased natriuretic peptide receptor 2 (NPR2) activity in granulosa cells and inhibited early follicle growth. In the testis, S1P increased the levels of cyclin-dependent kinase inhibitor 1A (p21) and apoptosis in Leydig cells, thus resulting in spermatogenesis arrest. These results indicate that Sgpl1 deletion increases intracellular S1P levels, resulting in the arrest of female and male germ cell development via different signaling pathways.
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Pignatti E, Flück CE. Adrenal cortex development and related disorders leading to adrenal insufficiency. Mol Cell Endocrinol 2021; 527:111206. [PMID: 33607267 DOI: 10.1016/j.mce.2021.111206] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 02/07/2023]
Abstract
The adult human adrenal cortex produces steroid hormones that are crucial for life, supporting immune response, glucose homeostasis, salt balance and sexual maturation. It consists of three histologically distinct and functionally specialized zones. The fetal adrenal forms from mesodermal material and produces predominantly adrenal C19 steroids from its fetal zone, which involutes after birth. Transition to the adult cortex occurs immediately after birth for the formation of the zona glomerulosa and fasciculata for aldosterone and cortisol production and continues through infancy until the zona reticularis for adrenal androgen production is formed with adrenarche. The development of this indispensable organ is complex and not fully understood. This article gives an overview of recent knowledge gained of adrenal biology from two perspectives: one, from basic science studying adrenal development, zonation and homeostasis; and two, from adrenal disorders identified in persons manifesting with various isolated or syndromic forms of primary adrenal insufficiency.
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Affiliation(s)
- Emanuele Pignatti
- Pediatric Endocrinology, Diabetology and Metabolism, Department of Pediatrics, Bern and Department of BioMedical Research, University Hospital Inselspital, University of Bern, 3010, Bern, Switzerland.
| | - Christa E Flück
- Pediatric Endocrinology, Diabetology and Metabolism, Department of Pediatrics, Bern and Department of BioMedical Research, University Hospital Inselspital, University of Bern, 3010, Bern, Switzerland.
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24
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Zhao P, Tassew GB, Lee JY, Oskouian B, Muñoz DP, Hodgin JB, Watson GL, Tang F, Wang JY, Luo J, Yang Y, King S, Krauss RM, Keller N, Saba JD. Efficacy of AAV9-mediated SGPL1 gene transfer in a mouse model of S1P lyase insufficiency syndrome. JCI Insight 2021; 6:145936. [PMID: 33755599 PMCID: PMC8119223 DOI: 10.1172/jci.insight.145936] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 03/17/2021] [Indexed: 12/26/2022] Open
Abstract
Sphingosine-1-phosphate lyase insufficiency syndrome (SPLIS) is a rare metabolic disorder caused by inactivating mutations in sphingosine-1-phosphate lyase 1 (SGPL1), which is required for the final step of sphingolipid metabolism. SPLIS features include steroid-resistant nephrotic syndrome and impairment of neurological, endocrine, and hematopoietic systems. Many affected individuals die within the first 2 years. No targeted therapy for SPLIS is available. We hypothesized that SGPL1 gene replacement would address the root cause of SPLIS, thereby serving as a universal treatment for the condition. As proof of concept, we evaluated the efficacy of adeno-associated virus 9–mediated transfer of human SGPL1 (AAV-SPL) given to newborn Sgpl1-KO mice that model SPLIS and die in the first weeks of life. Treatment dramatically prolonged survival and prevented nephrosis, neurodevelopmental delay, anemia, and hypercholesterolemia. STAT3 pathway activation and elevated proinflammatory and profibrogenic cytokines observed in KO kidneys were attenuated by treatment. Plasma and tissue sphingolipids were reduced in treated compared with untreated KO pups. SGPL1 expression and activity were measurable for at least 40 weeks. In summary, early AAV-SPL treatment prevents nephrosis, lipidosis, and neurological impairment in a mouse model of SPLIS. Our results suggest that SGPL1 gene replacement holds promise as a durable and universal targeted treatment for SPLIS.
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Affiliation(s)
- Piming Zhao
- Department of Pediatrics, UCSF, San Francisco, California, USA.,Cure Genetics, Suzhou, China
| | | | - Joanna Y Lee
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Babak Oskouian
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Denise P Muñoz
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Jeffrey B Hodgin
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| | - Gordon L Watson
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Felicia Tang
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Jen-Yeu Wang
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Jinghui Luo
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| | - Yingbao Yang
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| | - Sarah King
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Ronald M Krauss
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Nancy Keller
- Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Julie D Saba
- Department of Pediatrics, UCSF, San Francisco, California, USA
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25
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Drexler Y, Molina J, Mitrofanova A, Fornoni A, Merscher S. Sphingosine-1-Phosphate Metabolism and Signaling in Kidney Diseases. J Am Soc Nephrol 2021; 32:9-31. [PMID: 33376112 PMCID: PMC7894665 DOI: 10.1681/asn.2020050697] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
In the past few decades, sphingolipids and sphingolipid metabolites have gained attention because of their essential role in the pathogenesis and progression of kidney diseases. Studies in models of experimental and clinical nephropathies have described accumulation of sphingolipids and sphingolipid metabolites, and it has become clear that the intracellular sphingolipid composition of renal cells is an important determinant of renal function. Proper function of the glomerular filtration barrier depends heavily on the integrity of lipid rafts, which include sphingolipids as key components. In addition to contributing to the structural integrity of membranes, sphingolipid metabolites, such as sphingosine-1-phosphate (S1P), play important roles as second messengers regulating biologic processes, such as cell growth, differentiation, migration, and apoptosis. This review will focus on the role of S1P in renal cells and how aberrant extracellular and intracellular S1P signaling contributes to the pathogenesis and progression of kidney diseases.
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Affiliation(s)
- Yelena Drexler
- Katz Family Division of Nephrology and Hypertension/Peggy and Harold Katz Family Drug Discovery Center, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
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26
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Savas B, Astarita G, Aureli M, Sahali D, Ollero M. Gangliosides in Podocyte Biology and Disease. Int J Mol Sci 2020; 21:E9645. [PMID: 33348903 PMCID: PMC7766259 DOI: 10.3390/ijms21249645] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/07/2020] [Accepted: 12/14/2020] [Indexed: 02/07/2023] Open
Abstract
Gangliosides constitute a subgroup of glycosphingolipids characterized by the presence of sialic acid residues in their structure. As constituents of cellular membranes, in particular of raft microdomains, they exert multiple functions, some of them capital in cell homeostasis. Their presence in cells is tightly regulated by a balanced expression and function of the enzymes responsible for their biosynthesis, ganglioside synthases, and their degradation, glycosidases. The dysregulation of their abundance results in rare and common diseases. In this review, we make a point on the relevance of gangliosides and some of their metabolic precursors, such as ceramides, in the function of podocytes, the main cellular component of the glomerular filtration barrier, as well as their implications in podocytopathies. The results presented in this review suggest the pertinence of clinical lipidomic studies targeting these metabolites.
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Affiliation(s)
- Berkan Savas
- INSERM, IMRB, Univ Paris Est Créteil, F-94010 Créteil, France; (B.S.); (D.S.)
| | - Giuseppe Astarita
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, 20007 Washington, DC, USA;
| | - Massimo Aureli
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Milano Italy, 20090 Segrate (Milano), Italy;
| | - Dil Sahali
- INSERM, IMRB, Univ Paris Est Créteil, F-94010 Créteil, France; (B.S.); (D.S.)
- Service Néphrologie, AP-HP, Hôpital Henri Mondor, F-94010 Créteil, France
| | - Mario Ollero
- INSERM, IMRB, Univ Paris Est Créteil, F-94010 Créteil, France; (B.S.); (D.S.)
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27
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Buonocore F, McGlacken-Byrne SM, del Valle I, Achermann JC. Current Insights Into Adrenal Insufficiency in the Newborn and Young Infant. Front Pediatr 2020; 8:619041. [PMID: 33381483 PMCID: PMC7767829 DOI: 10.3389/fped.2020.619041] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022] Open
Abstract
Adrenal insufficiency (AI) is a potentially life-threatening condition that can be difficult to diagnose, especially if it is not considered as a potential cause of a child's clinical presentation or unexpected deterioration. Children who present with AI in early life can have signs of glucocorticoid deficiency (hyperpigmentation, hypoglycemia, prolonged jaundice, poor weight gain), mineralocorticoid deficiency (hypotension, salt loss, collapse), adrenal androgen excess (atypical genitalia), or associated features linked to a specific underlying condition. Here, we provide an overview of causes of childhood AI, with a focus on genetic conditions that present in the first few months of life. Reaching a specific diagnosis can have lifelong implications for focusing management in an individual, and for counseling the family about inheritance and the risk of recurrence.
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Affiliation(s)
| | | | | | - John C. Achermann
- Genetics & Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
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28
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Lipska-Ziętkiewicz BS, Ozaltin F, Hölttä T, Bockenhauer D, Bérody S, Levtchenko E, Vivarelli M, Webb H, Haffner D, Schaefer F, Boyer O. Genetic aspects of congenital nephrotic syndrome: a consensus statement from the ERKNet-ESPN inherited glomerulopathy working group. Eur J Hum Genet 2020; 28:1368-1378. [PMID: 32467597 PMCID: PMC7608398 DOI: 10.1038/s41431-020-0642-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 03/03/2020] [Accepted: 03/10/2020] [Indexed: 01/23/2023] Open
Abstract
Congenital nephrotic syndrome (CNS) is a heterogeneous group of disorders presenting with massive proteinuria within the first 3 months of life almost inevitably leading to end-stage kidney disease. The Work Group for the European Reference Network for Kidney Diseases (ERKNet) and the European Society for Pediatric Nephrology (ESPN) has developed consensus statement on genetic aspects of CNS diagnosis and management. The presented expert opinion recommends genetic diagnostics as the key diagnostic test to be ordered already during the initial evaluation of the patient, discusses which phenotyping workup should be performed and presents known genotype-phenotype correlations.
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Affiliation(s)
- Beata Stefania Lipska-Ziętkiewicz
- Clinical Genetics Unit, Department of Biology and Medical Genetics, Medical University of Gdańsk, Gdańsk, Poland.
- Centre for Rare Diseases, Medical University of Gdańsk, Gdańsk, Poland.
| | - Fatih Ozaltin
- Department of Pediatric Nephrology and Nephrogenetics Laboratory, Hacettepe University Faculty of Medicine, Ankara, Turkey.
| | - Tuula Hölttä
- Department of Pediatric Nephrology and Transplantation, The New Children's Hospital, HUS Helsinki University Hospital, Helsinki, Finland
| | - Detlef Bockenhauer
- UCL Department of Renal Medicine and Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Sandra Bérody
- Department of Pediatric Nephrology, Reference Center for Hereditary Kidney Diseases (MARHEA), Necker Hospital, APHP, 75015, Paris, France
| | - Elena Levtchenko
- Division of Pediatric Nephrology, Department of Pediatrics, University Hospitals Leuven; Department of Development & Regeneration, University of Leuven, Leuven, Belgium
| | - Marina Vivarelli
- Division of Nephrology and Dialysis, Department of Pediatric Subspecialties, Bambino Gesù Pediatric Hospital and Research Center, Rome, Italy
| | - Hazel Webb
- UCL Department of Renal Medicine and Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany
- Center for Congenital Kidney Diseases, Center for Rare Diseases, Hannover Medical School, Hannover, Germany
| | - Franz Schaefer
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany.
| | - Olivia Boyer
- Department of Pediatric Nephrology, Reference Center for Hereditary Kidney Diseases (MARHEA), Necker Hospital, APHP, 75015, Paris, France
- Laboratory of Hereditary Kidney Diseases, Imagine Institute, INSERM, Paris Descartes University, U1163, Paris, France
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29
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Martin KW, Weaver N, Alhasan K, Gumus E, Sullivan BR, Zenker M, Hildebrandt F, Saba JD. MRI Spectrum of Brain Involvement in Sphingosine-1-Phosphate Lyase Insufficiency Syndrome. AJNR Am J Neuroradiol 2020; 41:1943-1948. [PMID: 32855188 DOI: 10.3174/ajnr.a6746] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/01/2020] [Indexed: 12/12/2022]
Abstract
SGPL1 encodes sphingosine-1-phosphate lyase, the final enzyme of sphingolipid metabolism. In 2017, a condition featuring steroid-resistant nephrotic syndrome and/or adrenal insufficiency associated with pathogenic SGPL1 variants was reported. In addition to the main features of the disease, patients often exhibit a range of neurologic deficits. In a handful of cases, brain imaging results were described. However, high-quality imaging results and a systematic analysis of brain MR imaging findings associated with the condition are lacking. In this study, MR images from 4 new patients and additional published case reports were reviewed by a pediatric neuroradiologist. Analysis reveals recurring patterns of features in affected patients, including isolated callosal dysgenesis and prominent involvement of the globus pallidus, thalamus, and dentate nucleus, with progressive atrophy and worsening of brain lesions. MR imaging findings of abnormal deep gray nuclei, microcephaly, or callosal dysgenesis in an infant or young child exhibiting other typical clinical features of sphingosine-1-phosphate lyase insufficiency syndrome should trigger prompt genetic testing for SGPL1 mutations.
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Affiliation(s)
- K W Martin
- From the Department of Radiology (K.W.M.), UCSF Benioff Children's Hospital Oakland, Oakland, California
| | - N Weaver
- Division of Human Genetics (N.W.), Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - K Alhasan
- Department of Pediatrics (K.A.), College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - E Gumus
- Department of Medicine (E.G.), Harran University, Sanliurfa, Turkey
| | - B R Sullivan
- Division of Clinical Genetics (B.R.S.), Children's Mercy, Kansas City, Missouri
- Department of Pediatrics (B.R.S.), University of Missouri, Kansas City, Missouri
| | - M Zenker
- Institute of Genetics (M.Z.), Otto von Guericke Universitat, Magdeburg, Germany
| | - F Hildebrandt
- Department of Pediatrics (F.H.), Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - J D Saba
- UCSF Department of Pediatrics (J.D.S.), University of California, San Francisco, San Francisco, California
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30
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Mitrofanova A, Drexler Y, Merscher S, Fornoni A. Role of Sphingolipid Signaling in Glomerular Diseases: Focus on DKD and FSGS. JOURNAL OF CELLULAR SIGNALING 2020; 1:56-69. [PMID: 32914148 PMCID: PMC7480905 DOI: 10.33696/signaling.1.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sphingolipids are well-recognized as major players in the pathogenesis of many human diseases, including chronic kidney disease. The kidney is a very sensitive organ to alterations in sphingolipid metabolism. The critical issues to be addressed in this review relate to the role of sphingolipids and enzymes involved in sphingolipid metabolism in the pathogenesis of glomerular diseases with a special focus on podocytes, a key cellular component of the glomerular filtration barrier. Among several sphingolipids, we will highlight the role of ceramide, sphingosine, sphingosine-1-phosphate and ceramide-1-phosphate. Additionally, we will summarize the current knowledge with regard to the use of sphingolipids as therapeutic agents for the treatment of podocyte injury in kidney disease.
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Affiliation(s)
- Alla Mitrofanova
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida, USA
- Department of Surgery, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Yelena Drexler
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Sandra Merscher
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida, USA
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31
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Maharaj A, Williams J, Bradshaw T, Güran T, Braslavsky D, Casas J, Chan LF, Metherell LA, Prasad R. Sphingosine-1-phosphate lyase (SGPL1) deficiency is associated with mitochondrial dysfunction. J Steroid Biochem Mol Biol 2020; 202:105730. [PMID: 32682944 PMCID: PMC7482430 DOI: 10.1016/j.jsbmb.2020.105730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 01/12/2023]
Abstract
Deficiency in Sphingosine-1-phosphate lyase (S1P lyase) is associated with a multi-systemic disorder incorporating primary adrenal insufficiency (PAI), steroid resistant nephrotic syndrome and neurological dysfunction. Accumulation of sphingolipid intermediates, as seen with loss of function mutations in SGPL1, has been implicated in mitochondrial dysregulation, including alterations in mitochondrial membrane potentials and initiation of mitochondrial apoptosis. For the first time, we investigate the impact of S1P lyase deficiency on mitochondrial morphology and function using patient-derived human dermal fibroblasts and CRISPR engineered SGPL1-knockout HeLa cells. Reduced cortisol output in response to progesterone stimulation was observed in two patient dermal fibroblast cell lines. Mass spectrometric analysis of patient dermal fibroblasts revealed significantly elevated levels of sphingosine-1-phosphate, sphingosine, ceramide species and sphingomyelin when compared to control. Total mitochondrial volume was reduced in both S1P lyase deficient patient and HeLa cell lines. Mitochondrial dynamics and parameters of oxidative phosphorylation were altered when compared to matched controls, though differentially across the cell lines. Mitochondrial dysfunction may represent a major event in the pathogenesis of this disease, associated with severity of phenotype.
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Affiliation(s)
- A Maharaj
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - J Williams
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - T Bradshaw
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - T Güran
- Marmara University, School of Medicine, Department of Paediatric Endocrinology and Diabetes, Istanbul, Turkey
| | - D Braslavsky
- Centro de Investigaciones Endocrinológicas "Dr. Cesar Bergadá" (CEDIE) - CONICET - FEI - División de Endocrinología, Hospital de Niños "Ricardo Gutiérrez", Buenos Aires, Argentina
| | - J Casas
- Research Unit on BioActive Molecules (RUBAM), Department of Biomedicinal Chemistry, IQAC-CSIC, Jordi Girona 18-26, Barcelona, Spain
| | - L F Chan
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - L A Metherell
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - R Prasad
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, United Kingdom.
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32
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Zhao P, Liu ID, Hodgin JB, Benke PI, Selva J, Torta F, Wenk MR, Endrizzi JA, West O, Ou W, Tang E, Goh DLM, Tay SKH, Yap HK, Loh A, Weaver N, Sullivan B, Larson A, Cooper MA, Alhasan K, Alangari AA, Salim S, Gumus E, Chen K, Zenker M, Hildebrandt F, Saba JD. Responsiveness of sphingosine phosphate lyase insufficiency syndrome to vitamin B6 cofactor supplementation. J Inherit Metab Dis 2020; 43:1131-1142. [PMID: 32233035 PMCID: PMC8072405 DOI: 10.1002/jimd.12238] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/25/2020] [Accepted: 03/26/2020] [Indexed: 12/26/2022]
Abstract
Sphingosine-1-phosphate (S1P) lyase is a vitamin B6-dependent enzyme that degrades sphingosine-1-phosphate in the final step of sphingolipid metabolism. In 2017, a new inherited disorder was described caused by mutations in SGPL1, which encodes sphingosine phosphate lyase (SPL). This condition is referred to as SPL insufficiency syndrome (SPLIS) or alternatively as nephrotic syndrome type 14 (NPHS14). Patients with SPLIS exhibit lymphopenia, nephrosis, adrenal insufficiency, and/or neurological defects. No targeted therapy for SPLIS has been reported. Vitamin B6 supplementation has therapeutic activity in some genetic diseases involving B6-dependent enzymes, a finding ascribed largely to the vitamin's chaperone function. We investigated whether B6 supplementation might have activity in SPLIS patients. We retrospectively monitored responses of disease biomarkers in patients supplemented with B6 and measured SPL activity and sphingolipids in B6-treated patient-derived fibroblasts. In two patients, disease biomarkers responded to B6 supplementation. S1P abundance and activity levels increased and sphingolipids decreased in response to B6. One responsive patient is homozygous for an SPL R222Q variant present in almost 30% of SPLIS patients. Molecular modeling suggests the variant distorts the dimer interface which could be overcome by cofactor supplementation. We demonstrate the first potential targeted therapy for SPLIS and suggest that 30% of SPLIS patients might respond to cofactor supplementation.
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Affiliation(s)
- Piming Zhao
- Department of Pediatrics, Division of Hematology/Oncology, University of California, San Francisco, California
| | - Isaac D. Liu
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University Health System, Singapore, Singapore
| | - Jeffrey B. Hodgin
- Department of Pathology, University of Michigan Hospitals and Health Center, Ann Arbor, Michigan
| | - Peter I. Benke
- SLING, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jeremy Selva
- SLING, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Federico Torta
- SLING, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Markus R. Wenk
- SLING, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - James A. Endrizzi
- Department of Pediatrics, Division of Hematology/Oncology, University of California, San Francisco, California
| | - Olivia West
- Department of Pediatrics, Division of Hematology/Oncology, University of California, San Francisco, California
| | - Weixing Ou
- Department of Pediatrics, Division of Hematology/Oncology, University of California, San Francisco, California
| | - Emily Tang
- Department of Pediatrics, Division of Hematology/Oncology, University of California, San Francisco, California
| | - Denise Li-Meng Goh
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University Health System, Singapore, Singapore
| | - Stacey Kiat-Hong Tay
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University Health System, Singapore, Singapore
| | - Hui-Kim Yap
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University Health System, Singapore, Singapore
| | - Alwin Loh
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University Health System, Singapore, Singapore
| | - Nicole Weaver
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - Bonnie Sullivan
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
- Division of Clinical Genetics, Children’s Mercy Kansas City, Kansas City, Missouri
- Department of Pediatrics, University of Missouri, Kansas City, Missouri
| | - Austin Larson
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado
| | - Megan A. Cooper
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Khalid Alhasan
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah A. Alangari
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Suha Salim
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Evren Gumus
- Department of Medicine, Harran University, Sanliurfa, Turkey
| | - Karin Chen
- Department of Pediatrics, Division of Allergy and Immunology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Martin Zenker
- Institute of Human Genetics, Otto von Guericke University, Magdeburg, Germany
| | | | - Julie D. Saba
- Department of Pediatrics, Division of Hematology/Oncology, University of California, San Francisco, California
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Maharaj A, Theodorou D, Banerjee I(I, Metherell LA, Prasad R, Wallace D. A Sphingosine-1-Phosphate Lyase Mutation Associated With Congenital Nephrotic Syndrome and Multiple Endocrinopathy. Front Pediatr 2020; 8:151. [PMID: 32322566 PMCID: PMC7156639 DOI: 10.3389/fped.2020.00151] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 03/18/2020] [Indexed: 02/05/2023] Open
Abstract
Background: Loss of function mutations in SGPL1 are associated with Sphingosine-1-phosphate lyase insufficiency syndrome, comprising steroid resistant nephrotic syndrome, and primary adrenal insufficiency (PAI) in the majority of cases. SGPL1 encodes sphingosine-1-phosphate lyase (SGPL1) which is a major modulator of sphingolipid signaling. Case Presentation: A Pakistani male infant presented at 5 months of age with failure to thrive, nephrotic syndrome, primary adrenal insufficiency, hypothyroidism, and hypogonadism. Other systemic manifestations included persistent lymphopenia, ichthyosis, and motor developmental delay. Aged 9 months, he progressed rapidly into end stage oligo-anuric renal failure and subsequently died. Sanger sequencing of the entire coding region of SGPL1 revealed the novel association of a rare homozygous mutation (chr10:72619152, c.511A>G, p.N171D; MAF-1.701e-05) with the condition. Protein expression of the p.N171D mutant was markedly reduced compared to SGPL1 wild type when overexpressed in an SGPL1 knockout cell line, and associated with a severe clinical phenotype. Conclusions: The case further highlights the emerging phenotype of patients with loss-of-function SGPL1 mutations. Whilst nephrotic syndrome is a recognized feature of other disorders of sphingolipid metabolism, sphingosine-1-phosphate lyase insufficiency syndrome is unique amongst the sphingolipidoses in presenting with multiple endocrinopathies. Given the multi-systemic and progressive nature of this form of PAI/ nephrotic syndrome, a genetic diagnosis is crucial for optimal management and appropriate screening for comorbidities in these patients.
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Affiliation(s)
- Avinaash Maharaj
- Centre for Endocrinology, John Vane Science Centre, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Demetria Theodorou
- Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester, United Kingdom
| | - Indraneel (Indi) Banerjee
- Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester, United Kingdom
| | - Louise A. Metherell
- Centre for Endocrinology, John Vane Science Centre, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Rathi Prasad
- Centre for Endocrinology, John Vane Science Centre, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Dean Wallace
- Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester, United Kingdom
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Li G, Kidd J, Kaspar C, Dempsey S, Bhat OM, Camus S, Ritter JK, Gehr TWB, Gulbins E, Li PL. Podocytopathy and Nephrotic Syndrome in Mice with Podocyte-Specific Deletion of the Asah1 Gene: Role of Ceramide Accumulation in Glomeruli. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:1211-1223. [PMID: 32194052 DOI: 10.1016/j.ajpath.2020.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/20/2020] [Indexed: 12/26/2022]
Abstract
Lysosomal acid ceramidase (Ac) has been shown to be critical for ceramide hydrolysis and regulation of lysosome function and cellular homeostasis. In the present study, we generated a knockout mouse strain (Asah1fl/fl/PodoCre) with a podocyte-specific deletion of the α subunit (main catalytic subunit) of Ac. Although no significant morphologic changes in glomeruli were observed in these mice under light microscope, severe proteinuria and albuminuria were found in these podocyte-specific knockout mice compared with control genotype littermates. Transmission electron microscopic analysis showed that podocytes of the knockout mice had distinctive foot process effacement and microvillus formation. These functional and morphologic changes indicate the development of nephrotic syndrome in mice bearing the Asah1 podocyte-specific gene deletion. Ceramide accumulation determined by liquid chromatography-tandem mass spectrometry was demonstrated in isolated glomeruli of Asah1fl/fl/PodoCre mice compared with their littermates. By crossbreeding Asah1fl/fl/PodoCre mice with Smpd1-/- mice, we also produced a double knockout strain, Smpd1-/-/Asah1fl/fl/PodoCre, that also lacks Smpd1, the acid sphingomyelinase that hydrolyzes sphingomyelin to ceramide. These mice exhibited significantly lower levels of glomerular ceramide with decreased podocyte injury compared with Asah1fl/fl/PodoCre mice. These results strongly suggest that lysosomal Ac in podocytes is essential for the maintenance of the structural and functional integrity of podocytes.
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Affiliation(s)
- Guangbi Li
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Jason Kidd
- Division of Nephrology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Cristin Kaspar
- Division of Nephrology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Sara Dempsey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Owais M Bhat
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Sarah Camus
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Joseph K Ritter
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Todd W B Gehr
- Division of Nephrology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Erich Gulbins
- Department of Molecular Biology, University of Duisburg-Essen, Essen, Germany
| | - Pin-Lan Li
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia.
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Buonocore F, Achermann JC. Primary adrenal insufficiency: New genetic causes and their long-term consequences. Clin Endocrinol (Oxf) 2020; 92:11-20. [PMID: 31610036 PMCID: PMC6916405 DOI: 10.1111/cen.14109] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 10/03/2019] [Accepted: 10/12/2019] [Indexed: 12/23/2022]
Abstract
Primary adrenal insufficiency (PAI) is a potentially life-threatening condition that requires urgent diagnosis and treatment. Whilst the most common causes are congenital adrenal hyperplasia (CAH) in childhood and autoimmune adrenal insufficiency in adolescence and adulthood, more than 30 other physical and genetics cause of PAI have been reported. Reaching a specific diagnosis can have implications for management and for monitoring associated features, as well as for counselling families about recurrence risk in siblings and relatives. Here, we describe some recent insights into the genetics of adrenal insufficiency and associated molecular mechanisms. We discuss (a) the role of the nuclear receptors DAX-1 (NR0B1) and steroidogenic factor-1 (SF-1, NR5A1) in human adrenal and reproductive dysfunction; (b) multisystem growth restriction syndromes due to gain-of-function in the growth repressors CDKN1C (IMAGE syndrome) and SAMD9 (MIRAGE syndrome), or loss of POLE1; (c) nonclassic forms of STAR and P450scc/CYP11A1 insufficiency that present with a delayed-onset adrenal phenotype and represent a surprisingly prevalent cause of undiagnosed PAI; and (d) a new sphingolipidosis causing PAI due to defects in sphingosine-1-phosphate lyase-1 (SGPL1). Reaching a specific diagnosis can have life-long implications for management. In some situations, milder or nonclassic forms of these conditions can first present in adulthood and may have been labelled, "Addison's disease."
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Affiliation(s)
- Federica Buonocore
- Genetics & Genomic MedicineUCL Great Ormond Street Institute of Child HealthUniversity College LondonLondonUK
| | - John C. Achermann
- Genetics & Genomic MedicineUCL Great Ormond Street Institute of Child HealthUniversity College LondonLondonUK
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Druggable Sphingolipid Pathways: Experimental Models and Clinical Opportunities. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1274:101-135. [PMID: 32894509 DOI: 10.1007/978-3-030-50621-6_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Intensive research in the field of sphingolipids has revealed diverse roles in cell biological responses and human health and disease. This immense molecular family is primarily represented by the bioactive molecules ceramide, sphingosine, and sphingosine 1-phosphate (S1P). The flux of sphingolipid metabolism at both the subcellular and extracellular levels provides multiple opportunities for pharmacological intervention. The caveat is that perturbation of any single node of this highly regulated flux may have effects that propagate throughout the metabolic network in a dramatic and sometimes unexpected manner. Beginning with S1P, the receptors for which have thus far been the most clinically tractable pharmacological targets, this review will describe recent advances in therapeutic modulators targeting sphingolipids, their chaperones, transporters, and metabolic enzymes.
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Taylor VA, Stone HK, Schuh MP, Zhao X, Setchell KD, Erkan E. Disarranged Sphingolipid Metabolism From Sphingosine-1-Phosphate Lyase Deficiency Leads to Congenital Nephrotic Syndrome. Kidney Int Rep 2019; 4:1763-1769. [PMID: 31844815 PMCID: PMC6895586 DOI: 10.1016/j.ekir.2019.07.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/28/2019] [Accepted: 07/31/2019] [Indexed: 11/28/2022] Open
Affiliation(s)
- Veronica A Taylor
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Hillarey K Stone
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Meredith P Schuh
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Xueheng Zhao
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Kenneth D Setchell
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Elif Erkan
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
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Mitrofanova A, Mallela SK, Ducasa GM, Yoo TH, Rosenfeld-Gur E, Zelnik ID, Molina J, Varona Santos J, Ge M, Sloan A, Kim JJ, Pedigo C, Bryn J, Volosenco I, Faul C, Zeidan YH, Garcia Hernandez C, Mendez AJ, Leibiger I, Burke GW, Futerman AH, Barisoni L, Ishimoto Y, Inagi R, Merscher S, Fornoni A. SMPDL3b modulates insulin receptor signaling in diabetic kidney disease. Nat Commun 2019; 10:2692. [PMID: 31217420 PMCID: PMC6584700 DOI: 10.1038/s41467-019-10584-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 05/15/2019] [Indexed: 12/22/2022] Open
Abstract
Sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b) is a lipid raft enzyme that regulates plasma membrane (PM) fluidity. Here we report that SMPDL3b excess, as observed in podocytes in diabetic kidney disease (DKD), impairs insulin receptor isoform B-dependent pro-survival insulin signaling by interfering with insulin receptor isoforms binding to caveolin-1 in the PM. SMPDL3b excess affects the production of active sphingolipids resulting in decreased ceramide-1-phosphate (C1P) content as observed in human podocytes in vitro and in kidney cortexes of diabetic db/db mice in vivo. Podocyte-specific Smpdl3b deficiency in db/db mice is sufficient to restore kidney cortex C1P content and to protect from DKD. Exogenous administration of C1P restores IR signaling in vitro and prevents established DKD progression in vivo. Taken together, we identify SMPDL3b as a modulator of insulin signaling and demonstrate that supplementation with exogenous C1P may represent a lipid therapeutic strategy to treat diabetic complications such as DKD.
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Affiliation(s)
- A Mitrofanova
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Department of Surgery, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - S K Mallela
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - G M Ducasa
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - T H Yoo
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Department of Internal Medicine, College of Medicine, Yonsei University, Seoul, 03722, Korea
| | - E Rosenfeld-Gur
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - I D Zelnik
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - J Molina
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - J Varona Santos
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - M Ge
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - A Sloan
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - J J Kim
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - C Pedigo
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Department of Internal Medicine, Yale University School of Medicine, New Haven, 06510, CT, USA
| | - J Bryn
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - I Volosenco
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Lewis Gale Medical Center, Salem, 24153, VI, USA
| | - C Faul
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, 35233, AL, USA
| | - Y H Zeidan
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Department of Radiation Oncology, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Department of Radiation Oncology, American University of Beirut, Beirut, 1107 2020, Lebanon
| | - C Garcia Hernandez
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Department of Radiation Oncology, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - A J Mendez
- Diabetes Research Institute, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - I Leibiger
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, 17176, Sweden
| | - G W Burke
- Department of Surgery, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Diabetes Research Institute, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - A H Futerman
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - L Barisoni
- Department of Pathology, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - Y Ishimoto
- Division of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, 113-8654, Japan
- Division of CKD Pathophysiology, University of Tokyo Graduate School of Medicine, Tokyo, 113-8654, Japan
| | - R Inagi
- Division of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, 113-8654, Japan
- Division of CKD Pathophysiology, University of Tokyo Graduate School of Medicine, Tokyo, 113-8654, Japan
| | - S Merscher
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA
| | - A Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA.
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, 33136, FL, USA.
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Brommage R, Powell DR, Vogel P. Predicting human disease mutations and identifying drug targets from mouse gene knockout phenotyping campaigns. Dis Model Mech 2019; 12:dmm038224. [PMID: 31064765 PMCID: PMC6550044 DOI: 10.1242/dmm.038224] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Two large-scale mouse gene knockout phenotyping campaigns have provided extensive data on the functions of thousands of mammalian genes. The ongoing International Mouse Phenotyping Consortium (IMPC), with the goal of examining all ∼20,000 mouse genes, has examined 5115 genes since 2011, and phenotypic data from several analyses are available on the IMPC website (www.mousephenotype.org). Mutant mice having at least one human genetic disease-associated phenotype are available for 185 IMPC genes. Lexicon Pharmaceuticals' Genome5000™ campaign performed similar analyses between 2000 and the end of 2008 focusing on the druggable genome, including enzymes, receptors, transporters, channels and secreted proteins. Mutants (4654 genes, with 3762 viable adult homozygous lines) with therapeutically interesting phenotypes were studied extensively. Importantly, phenotypes for 29 Lexicon mouse gene knockouts were published prior to observations of similar phenotypes resulting from homologous mutations in human genetic disorders. Knockout mouse phenotypes for an additional 30 genes mimicked previously published human genetic disorders. Several of these models have helped develop effective treatments for human diseases. For example, studying Tph1 knockout mice (lacking peripheral serotonin) aided the development of telotristat ethyl, an approved treatment for carcinoid syndrome. Sglt1 (also known as Slc5a1) and Sglt2 (also known as Slc5a2) knockout mice were employed to develop sotagliflozin, a dual SGLT1/SGLT2 inhibitor having success in clinical trials for diabetes. Clinical trials evaluating inhibitors of AAK1 (neuropathic pain) and SGLT1 (diabetes) are underway. The research community can take advantage of these unbiased analyses of gene function in mice, including the minimally studied 'ignorome' genes.
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Affiliation(s)
- Robert Brommage
- Department of Metabolism Research, Lexicon Pharmaceuticals, 8800 Technology Forest Place, The Woodlands, TX 77381, USA
| | - David R Powell
- Department of Metabolism Research, Lexicon Pharmaceuticals, 8800 Technology Forest Place, The Woodlands, TX 77381, USA
| | - Peter Vogel
- St. Jude Children's Research Hospital, Pathology, MS 250, Room C5036A, 262 Danny Thomas Place, Memphis, TN 38105, USA
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Maharaj A, Maudhoo A, Chan LF, Novoselova T, Prasad R, Metherell LA, Guasti L. Isolated glucocorticoid deficiency: Genetic causes and animal models. J Steroid Biochem Mol Biol 2019; 189:73-80. [PMID: 30817990 DOI: 10.1016/j.jsbmb.2019.02.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 01/04/2019] [Accepted: 02/25/2019] [Indexed: 12/27/2022]
Abstract
Hereditary adrenocorticotropin (ACTH) resistance syndromes encompass the genetically heterogeneous isolated or Familial Glucocorticoid Deficiency (FGD) and the distinct clinical entity known as Triple A syndrome. The molecular basis of adrenal resistance to ACTH includes defects in ligand binding, MC2R/MRAP receptor trafficking, cellular redox balance, cholesterol synthesis and sphingolipid metabolism. Biochemically, this manifests as ACTH excess in the setting of hypocortisolaemia. Triple A syndrome is an inherited condition involving a tetrad of adrenal insufficiency, achalasia, alacrima and neuropathy. FGD is an autosomal recessive condition characterized by the presence of isolated glucocorticoid deficiency, classically in the setting of preserved mineralocorticoid secretion. Primarily there are three established subtypes of the disease: FGD 1, FGD2 and FGD3 corresponding to mutations in the Melanocortin 2 receptor MC2R (25%), Melanocortin 2 receptor accessory protein MRAP (20%), and Steroidogenic acute regulatory protein STAR (5-10%) respectively. Together, mutations in these 3 genes account for approximately half of cases. Whole exome sequencing in patients negative for MC2R, MRAP and STAR mutations, identified mutations in minichromosome maintenance 4 MCM4, nicotinamide nucleotide transhydrogenase NNT, thioredoxin reductase 2 TXNRD2, cytochrome p450scc CYP11A1, and sphingosine 1-phosphate lyase SGPL1 accounting for a further 10% of FGD. These novel genes have linked replicative and oxidative stress and altered redox potential as a mechanism of adrenocortical damage. However, a genetic diagnosis is still unclear in about 40% of cases. We describe here an updated list of FGD genes and provide a description of relevant mouse models that, despite some being flawed, have been precious allies in the understanding of FGD pathobiology.
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Affiliation(s)
- Avinaash Maharaj
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Ashwini Maudhoo
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Li F Chan
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Tatiana Novoselova
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Rathi Prasad
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Louise A Metherell
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, Charterhouse Square, London, United Kingdom
| | - Leonardo Guasti
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, Charterhouse Square, London, United Kingdom.
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Saba JD. Fifty years of lyase and a moment of truth: sphingosine phosphate lyase from discovery to disease. J Lipid Res 2019; 60:456-463. [PMID: 30635364 PMCID: PMC6399507 DOI: 10.1194/jlr.s091181] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 12/31/2018] [Indexed: 12/17/2022] Open
Abstract
Sphingosine phosphate lyase (SPL) is the final enzyme in the sphingolipid degradative pathway, catalyzing the irreversible cleavage of long-chain base phosphates (LCBPs) to yield a long-chain aldehyde and ethanolamine phosphate (EP). SPL guards the sole exit point of sphingolipid metabolism. Its inactivation causes product depletion and accumulation of upstream sphingolipid intermediates. The main substrate of the reaction, sphingosine-1-phosphate (S1P), is a bioactive lipid that controls immune-cell trafficking, angiogenesis, cell transformation, and other fundamental processes. The products of the SPL reaction contribute to phospholipid biosynthesis and programmed cell-death activation. The main features of SPL enzyme activity were first described in detail by Stoffel et al. in 1969. The first SPL-encoding gene was cloned from budding yeast in 1997. Reverse and forward genetic strategies led to the rapid identification of other genes in the pathway and their homologs in other species. Genetic manipulation of SPL-encoding genes in model organisms has revealed the contribution of sphingolipid metabolism to development, physiology, and host-pathogen interactions. In 2017, recessive mutations in the human SPL gene SGPL1 were identified as the cause of a novel inborn error of metabolism associated with nephrosis, endocrine defects, immunodeficiency, acanthosis, and neurological problems. We refer to this condition as SPL insufficiency syndrome (SPLIS). Here, we share our perspective on the 50-year history of SPL from discovery to disease, focusing on insights provided by model organisms regarding the pathophysiology of SPLIS and how SPLIS raises the possibility of a hidden role for sphingolipids in other disease conditions.
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Affiliation(s)
- Julie D Saba
- Children's Hospital Oakland Research Institute, University of California, San Francisco Benioff Children's Hospital Oakland, Oakland, CA 94609
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Yeast Mpo1 Is a Novel Dioxygenase That Catalyzes the α-Oxidation of a 2-Hydroxy Fatty Acid in an Fe 2+-Dependent Manner. Mol Cell Biol 2019; 39:MCB.00428-18. [PMID: 30530523 DOI: 10.1128/mcb.00428-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 12/02/2018] [Indexed: 01/05/2023] Open
Abstract
Phytosphingosine (PHS) is the major long-chain base component of sphingolipids in Saccharomyces cerevisiae The PHS metabolic pathway includes a fatty acid (FA) α-oxidation reaction. Recently, we identified the novel protein Mpo1, which is involved in PHS metabolism. However, the details of the FA α-oxidation reaction and the role of Mpo1 in PHS metabolism remained unclear. In the present study, we revealed that Mpo1 is involved in the α-oxidation of 2-hydroxy (2-OH) palmitic acid (C16:0-COOH) in the PHS metabolic pathway. Our in vitro assay revealed that not only the Mpo1-containing membrane fraction but also the soluble fraction was required for the α-oxidation of 2-OH C16:0-COOH. The addition of Fe2+ eliminated the need for the soluble fraction. Purified Mpo1 converted 2-OH C16:0-COOH to C15:0-COOH in the presence of Fe2+, indicating that Mpo1 is the enzyme body responsible for catalyzing the FA α-oxidation reaction. This reaction was also found to require an oxygen molecule. Our findings indicate that Mpo1 catalyzes the FA α-oxidation reaction as 2-OH fatty acid dioxygenase, mediated by iron(IV) peroxide. Although numerous Mpo1 homologs exist in bacteria, fungi, protozoa, and plants, their functions had not yet been clarified. However, our findings suggest that these family members function as dioxygenases.
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Karsai G, Kraft F, Haag N, Korenke GC, Hänisch B, Othman A, Suriyanarayanan S, Steiner R, Knopp C, Mull M, Bergmann M, Schröder JM, Weis J, Elbracht M, Begemann M, Hornemann T, Kurth I. DEGS1-associated aberrant sphingolipid metabolism impairs nervous system function in humans. J Clin Invest 2019; 129:1229-1239. [PMID: 30620338 DOI: 10.1172/jci124159] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 12/21/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Sphingolipids are important components of cellular membranes and functionally associated with fundamental processes such as cell differentiation, neuronal signaling, and myelin sheath formation. Defects in the synthesis or degradation of sphingolipids leads to various neurological pathologies; however, the entire spectrum of sphingolipid metabolism disorders remains elusive. METHODS A combined approach of genomics and lipidomics was applied to identify and characterize a human sphingolipid metabolism disorder. RESULTS By whole-exome sequencing in a patient with a multisystem neurological disorder of both the central and peripheral nervous systems, we identified a homozygous p.Ala280Val variant in DEGS1, which catalyzes the last step in the ceramide synthesis pathway. The blood sphingolipid profile in the patient showed a significant increase in dihydro sphingolipid species that was further recapitulated in patient-derived fibroblasts, in CRISPR/Cas9-derived DEGS1-knockout cells, and by pharmacological inhibition of DEGS1. The enzymatic activity in patient fibroblasts was reduced by 80% compared with wild-type cells, which was in line with a reduced expression of mutant DEGS1 protein. Moreover, an atypical and potentially neurotoxic sphingosine isomer was identified in patient plasma and in cells expressing mutant DEGS1. CONCLUSION We report DEGS1 dysfunction as the cause of a sphingolipid disorder with hypomyelination and degeneration of both the central and peripheral nervous systems. TRIAL REGISTRATION Not applicable. FUNDING Seventh Framework Program of the European Commission, Swiss National Foundation, Rare Disease Initiative Zurich.
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Affiliation(s)
- Gergely Karsai
- Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland.,Institute for Clinical Chemistry, University Hospital, Zürich, Switzerland
| | - Florian Kraft
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Natja Haag
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - G Christoph Korenke
- Clinic for Neuropediatrics and Congenital Metabolic Diseases, University Clinic for Paediatrics and Adolescent Medicine, Oldenburg, Germany
| | - Benjamin Hänisch
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Alaa Othman
- Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland.,Institute for Clinical Chemistry, University Hospital, Zürich, Switzerland
| | - Saranya Suriyanarayanan
- Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland.,Institute for Clinical Chemistry, University Hospital, Zürich, Switzerland
| | - Regula Steiner
- Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland.,Institute for Clinical Chemistry, University Hospital, Zürich, Switzerland
| | - Cordula Knopp
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Michael Mull
- Department of Diagnostic and Interventional Neuroradiology, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Markus Bergmann
- Institute for Neuropathology, Hospital Bremen-Mitte, Bremen, Germany
| | - J Michael Schröder
- Institute of Neuropathology, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Joachim Weis
- Institute of Neuropathology, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Miriam Elbracht
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Matthias Begemann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Thorsten Hornemann
- Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland.,Institute for Clinical Chemistry, University Hospital, Zürich, Switzerland
| | - Ingo Kurth
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Dunn TM, Tifft CJ, Proia RL. A perilous path: the inborn errors of sphingolipid metabolism. J Lipid Res 2019; 60:475-483. [PMID: 30683667 PMCID: PMC6399501 DOI: 10.1194/jlr.s091827] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/13/2019] [Indexed: 01/19/2023] Open
Abstract
The sphingolipid (SL) metabolic pathway generates structurally diverse lipids that have roles as membrane constituents and as bioactive signaling molecules. The influence of the SL metabolic pathway in biology is pervasive; it exists in all mammalian cells and has roles in many cellular and physiological pathways. Human genetic diseases have long been recognized to be caused by mutations in the pathway, but until recently these mutational defects were only known to affect lysosomal SL degradation. Now, with a nearly complete delineation of the genes constituting the SL metabolic pathway, a growing number of additional genetic disorders caused by mutations in genes within other sectors of the pathway (de novo ceramide synthesis, glycosphingolipid synthesis, and nonlysosomal SL degradation) have been recognized. Although these inborn disorders of SL metabolism are clinically heterogeneous, some common pathogenic mechanisms, derived from the unique properties and functions of the SLs, underlie several of the diseases. These mechanisms include overaccumulation of toxic or bioactive lipids and the disruption of specific critical cellular and physiological processes. Many of these diseases also have commonalities in physiological systems affected, such as the nervous system and skin. While inborn disorders of SL metabolism are rare, gene variants in the pathway have been linked to increased susceptibility to Parkinson’s disease and childhood asthma, implying that the SL metabolic pathway may have a role in these disorders. A more complete understanding of the inborn errors of SL metabolism promises new insights into the convergence of their pathogenesis with those of common human diseases.
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Affiliation(s)
- Teresa M Dunn
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814
| | - Cynthia J Tifft
- Office of the Clinical Director and Medical Genetics Branch National Human Genome Research Institute, Bethesda, MD 20892
| | - Richard L Proia
- Genetics of Development and Disease Branch National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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Choi YJ, Saba JD. Sphingosine phosphate lyase insufficiency syndrome (SPLIS): A novel inborn error of sphingolipid metabolism. Adv Biol Regul 2018; 71:128-140. [PMID: 30274713 DOI: 10.1016/j.jbior.2018.09.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 09/12/2018] [Accepted: 09/12/2018] [Indexed: 02/06/2023]
Abstract
Sphingosine-1-phosphate lyase (SPL) is an intracellular enzyme that controls the final step in the sphingolipid degradative pathway, the only biochemical pathway for removal of sphingolipids. Specifically, SPL catalyzes the cleavage of sphingosine 1-phosphate (S1P) at the C2-3 carbon bond, resulting in its irreversible degradation to phosphoethanolamine (PE) and hexadecenal. The substrate of the reaction, S1P, is a bioactive sphingolipid metabolite that signals through a family of five G protein-coupled S1P receptors (S1PRs) to mediate biological activities including cell migration, cell survival/death/proliferation and cell extrusion, thereby contributing to development, physiological functions and - when improperly regulated - the pathophysiology of disease. In 2017, several groups including ours reported a novel childhood syndrome that featured a wide range of presentations including fetal hydrops, steroid-resistant nephrotic syndrome (SRNS), primary adrenal insufficiency (PAI), rapid or insidious neurological deterioration, immunodeficiency, acanthosis and endocrine abnormalities. In all cases, the disease was attributed to recessive mutations in the human SPL gene, SGPL1. We now refer to this condition as SPL Insufficiency Syndrome, or SPLIS. Some features of this new sphingolipidosis were predicted by the reported phenotypes of Sgpl1 homozygous null mice that serve as vertebrate SPLIS disease models. However, other SPLIS features reveal previously unrecognized roles for SPL in human physiology. In this review, we briefly summarize the biochemistry, functions and regulation of SPL, the main clinical and biochemical features of SPLIS and what is known about the pathophysiology of this condition from murine and cell models. Lastly, we consider potential therapeutic strategies for the treatment of SPLIS patients.
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Affiliation(s)
- Youn-Jeong Choi
- UCSF Benioff Children's Hospital Oakland, Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA, 94609, USA
| | - Julie D Saba
- UCSF Benioff Children's Hospital Oakland, Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA, 94609, USA.
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Abstract
Primary adrenal insufficiency (PAI) is a life-threatening disorder of adrenal cortex which is characterized by deficient biosynthesis of glucocorticoids, with or without deficiency in mineralocorticoids and adrenal androgens. Typical manifestations of primary adrenal insufficiency include hyperpigmentation, hypotension, hypoglycaemia, hyponatremia with or without hyperkalemia that are generally preceded by nonspecific symptoms at the onset. Recessively inherited monogenic disorders constitute the largest group of primary adrenal insufficiency in children. The diagnostic process of primary adrenal insufficiency includes demonstration of low cortisol concentrations along with high plasma ACTH and identifying the cause of the disorder. Specific molecular diagnosis is achieved in more than 80% of children with PAI by detailed clinical and biochemical characterization integrated with advanced molecular tools. Hormone replacement therapy determined on the type and the severity of deficient adrenocortical hormones is the mainstay of treatment. Optimized methods of steroid hormone delivery, improved monitoring of hormone replacement along with intensive education of patients and families on the rules during intercurrent illness and stress will significantly reduce the morbidity and mortality associated with primary adrenal insufficiency.
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Affiliation(s)
- Tarik Kirkgoz
- Marmara University School of Medicine, Department of Paediatric Endocrinology and Diabetes, Istanbul, Turkey.
| | - Tulay Guran
- Marmara University School of Medicine, Department of Paediatric Endocrinology and Diabetes, Istanbul, Turkey.
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Bamborschke D, Pergande M, Becker K, Koerber F, Dötsch J, Vierzig A, Weber LT, Cirak S. A novel mutation in sphingosine-1-phosphate lyase causing congenital brain malformation. Brain Dev 2018; 40:480-483. [PMID: 29501407 DOI: 10.1016/j.braindev.2018.02.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/12/2018] [Accepted: 02/13/2018] [Indexed: 10/17/2022]
Abstract
INTRODUCTION Recently recessive mutations in sphingosine-1-phosphate lyase (SGPL1) have been published as a cause of syndromic congenital nephrotic syndrome with adrenal insufficiency. We have identified a case with fetal hydrops and brain malformations due to a mutation in SGPL1. CASE REPORT We report a patient presenting with severe fetal hydrops, congenital nephrotic syndrome and adrenal calcifications. MRI imaging showed generalized cortical atrophy with simplified gyral pattern and hypoplastic temporal lobes as well as cerebellar hypoplasia and hyperintensity in the pons. The boy deceased at 6 weeks of age. Via whole exome sequencing, we identified a novel homozygous frameshift mutation c.1233delC (p.Phe411Leufs∗56) in SGPL1. CONCLUSION In our patient, we describe a novel mutation in sphingosine-1-phosphate lyase (SGPL1) leading to severe brain malformation. Neurodevelopmental phenotypes have been reported earlier, but not described in detail. To this end, we present a review on all published SGPL1-mutations and genotype-phenotype correlations focusing on neurodevelopmental outcomes. We hypothesized on the severe neurological phenotypes, which might be due to disruption of neuronal autophagy. Mutations in SGPL1 shall be considered in the differential diagnosis of fetal hydrops as well as congenital brain malformations and neuropathies.
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Affiliation(s)
- Daniel Bamborschke
- Center for Molecular Medicine Cologne, Cologne, Germany; Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Matthias Pergande
- Center for Molecular Medicine Cologne, Cologne, Germany; Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Kerstin Becker
- Center for Molecular Medicine Cologne, Cologne, Germany; Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Friederike Koerber
- Department of Pediatric Radiology, University Hospital of Cologne, Cologne, Germany
| | - Jörg Dötsch
- Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Anne Vierzig
- Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Lutz T Weber
- Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Sebahattin Cirak
- Center for Molecular Medicine Cologne, Cologne, Germany; Department of Pediatrics, University Hospital of Cologne, Cologne, Germany.
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Sunter G, Enver EO, Akbarzade A, Turan S, Vatansever P, Gunal DI, Haklar G, Bereket A, Agan K, Guran T. Acquired modification of sphingosine-1-phosphate lyase activity is not related to adrenal insufficiency. BMC Neurol 2018; 18:48. [PMID: 29685115 PMCID: PMC5911956 DOI: 10.1186/s12883-018-1049-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 04/16/2018] [Indexed: 12/02/2022] Open
Abstract
Background Congenital sphingosine-1-phosphate (S1P) lyase deficiency due to biallelic mutations in SGPL1 gene has recently been described in association with primary adrenal insufficiency and steroid-resistant nephrotic syndrome. S1P lyase, on the other hand, is therapeutically inhibited by fingolimod which is an oral drug for relapsing multiple sclerosis (MS). Effects of this treatment on adrenal function has not yet been evaluated. We aimed to test adrenal function of MS patients receiving long-term fingolimod treatment. Methods Nineteen patients (14 women) with MS receiving oral fingolimod (Gilenya®, Novartis) therapy were included. Median age was 34.2 years (range; 21.3–44.6 years). Median duration of fingolimod treatment was 32 months (range; 6–52 months) at a dose of 0.5 mg/day. Basal and ACTH-stimulated adrenal steroid measurements were evaluated simultaneously employing LC-MS/MS based steroid panel. Basal steroid concentrations were also compared to that of sex- and age-matched healthy subjects. Cortisol and 11-deoxycortisol, 11-deoxycorticosterone and dehydroepiandrosterone were used to assess glucocorticoid, mineralocorticoid and sex steroid producing pathways, respectively. Results Basal ACTH concentrations of the patients were 20.8 pg/mL (6.8–37.8 pg/mL) (normal range; 5–65 pg/mL). There was no significant difference in the basal concentrations of cortisol, 11-deoxycortisol, 11-deoxycorticosterone and dehydroepiandrosterone between patients and controls (p = 0.11, 0.058, 0.74, 0.15; respectively). All patients showed adequate cortisol response to 250 mcg IV ACTH stimulation (243 ng/mL, range; 197–362 ng/mL). There was no significant correlation between duration of fingolimod treatment and basal or ACTH-stimulated cortisol or change in cortisol concentrations during ACTH stimulation test (p = 0.57, 0.66 and 0.21, respectively). Conclusion Modification and inhibition of S1P lyase activity by the long-term therapeutic use of fingolimod is not associated with adrenal insufficiency in adult patients with MS. This suggests that S1P lyase has potentially a critical role on adrenal development rather than the function of a fully mature adrenal gland.
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Affiliation(s)
- Gulin Sunter
- Department of Neurology, Marmara University, Istanbul, Turkey
| | - Ece Oge Enver
- Department of Paediatric Endocrinology and Diabetes, Marmara University, Fevzi Cakmak Mh. Mimar Sinan Cd.No 41., Ustkaynarca/Pendik, 34899, Istanbul, Turkey
| | - Azad Akbarzade
- Department of Paediatric Endocrinology and Diabetes, Marmara University, Fevzi Cakmak Mh. Mimar Sinan Cd.No 41., Ustkaynarca/Pendik, 34899, Istanbul, Turkey
| | - Serap Turan
- Department of Paediatric Endocrinology and Diabetes, Marmara University, Fevzi Cakmak Mh. Mimar Sinan Cd.No 41., Ustkaynarca/Pendik, 34899, Istanbul, Turkey
| | - Pinar Vatansever
- Department of Biochemistry, Marmara University, Istanbul, Turkey
| | | | - Goncagul Haklar
- Department of Biochemistry, Marmara University, Istanbul, Turkey
| | - Abdullah Bereket
- Department of Paediatric Endocrinology and Diabetes, Marmara University, Fevzi Cakmak Mh. Mimar Sinan Cd.No 41., Ustkaynarca/Pendik, 34899, Istanbul, Turkey
| | - Kadriye Agan
- Department of Neurology, Marmara University, Istanbul, Turkey
| | - Tulay Guran
- Department of Paediatric Endocrinology and Diabetes, Marmara University, Fevzi Cakmak Mh. Mimar Sinan Cd.No 41., Ustkaynarca/Pendik, 34899, Istanbul, Turkey.
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Hannah-Shmouni F, Stratakis CA. An overview of inborn errors of metabolism manifesting with primary adrenal insufficiency. Rev Endocr Metab Disord 2018; 19:53-67. [PMID: 29956047 PMCID: PMC6204320 DOI: 10.1007/s11154-018-9447-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Primary adrenal insufficiency (PAI) results from an inability to produce adequate amounts of steroid hormones from the adrenal cortex. The most common causes of PAI are autoimmune adrenalitis (Addison's disease), infectious diseases, adrenalectomy, neoplasia, medications, and various rare genetic syndromes and inborn errors of metabolism that typically present in childhood although late-onset presentations are becoming increasingly recognized. The prevalence of PAI in Western countries is approximately 140 cases per million, with an incidence of 4 per 1,000,000 per year. Several pitfalls in the genetic diagnosis of patients with PAI exist. In this review, we provide an in-depth discussion and overview on the inborn errors of metabolism manifesting with PAI, including genetic diagnosis, genotype-phenotype relationships and counseling of patients and their families with a focus on various enzymatic deficiencies of steroidogenesis.
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Affiliation(s)
- Fady Hannah-Shmouni
- Section on Endocrinology & Genetics, The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Building 10, CRC, Room 1-3330, 10 Center Dr., MSC1103, Bethesda, MD, 20892, USA
| | - Constantine A Stratakis
- Section on Endocrinology & Genetics, The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Building 10, CRC, Room 1-3330, 10 Center Dr., MSC1103, Bethesda, MD, 20892, USA.
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50
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Huwiler A, Pfeilschifter J. Sphingolipid signaling in renal fibrosis. Matrix Biol 2018; 68-69:230-247. [PMID: 29343457 DOI: 10.1016/j.matbio.2018.01.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 01/08/2018] [Accepted: 01/08/2018] [Indexed: 12/28/2022]
Abstract
Over the last decade, various sphingolipid subspecies have gained increasing attention as important signaling molecules that regulate a multitude of physiological and pathophysiological processes including inflammation and tissue remodeling. These mediators include ceramide, sphingosine 1-phosphate (S1P), the cerebroside glucosylceramide, lactosylceramide, and the gangliosides GM3 and Gb3. These lipids have been shown to accumulate in various chronic kidney diseases that typically end in renal fibrosis and ultimately renal failure. This review will summarize the effects and contributions of those enzymes that regulate the generation and interconversion of these lipids, notably the acid sphingomyelinase, the acid sphingomyelinase-like protein SMPDL3B, the sphingosine kinases, the S1P lyase, the glucosylceramide synthase, the GM3 synthase, and the α-galactosidase A, to renal fibrotic diseases. Strategies of manipulating these enzymes for therapeutic purposes and the impact of existing drugs on renal pathologies will be discussed.
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Affiliation(s)
- Andrea Huwiler
- Institute of Pharmacology, University of Bern, Inselspital INO-F, CH-3010 Bern, Switzerland.
| | - Josef Pfeilschifter
- Institute of General Pharmacology and Toxicology, University Hospital Frankfurt, Goethe- University, Frankfurt am Main, Germany
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