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Randle RK, Amara VR, Popik W. IFI16 Is Indispensable for Promoting HIF-1α-Mediated APOL1 Expression in Human Podocytes under Hypoxic Conditions. Int J Mol Sci 2024; 25:3324. [PMID: 38542298 PMCID: PMC10970439 DOI: 10.3390/ijms25063324] [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: 01/30/2024] [Revised: 02/28/2024] [Accepted: 03/13/2024] [Indexed: 04/04/2024] Open
Abstract
Genetic variants in the protein-coding regions of APOL1 are associated with an increased risk and progression of chronic kidney disease (CKD) in African Americans. Hypoxia exacerbates CKD progression by stabilizing HIF-1α, which induces APOL1 transcription in kidney podocytes. However, the contribution of additional mediators to regulating APOL1 expression under hypoxia in podocytes is unknown. Here, we report that a transient accumulation of HIF-1α in hypoxia is sufficient to upregulate APOL1 expression in podocytes through a cGAS/STING/IRF3-independent pathway. Notably, IFI16 ablation impedes hypoxia-driven APOL1 expression despite the nuclear accumulation of HIF-1α. Co-immunoprecipitation assays indicate no direct interaction between IFI16 and HIF-1α. Our studies identify hypoxia response elements (HREs) in the APOL1 gene enhancer/promoter region, showing increased HIF-1α binding to HREs located in the APOL1 gene enhancer. Luciferase reporter assays confirm the role of these HREs in transcriptional activation. Chromatin immunoprecipitation (ChIP)-qPCR assays demonstrate that IFI16 is not recruited to HREs, and IFI16 deletion reduces HIF-1α binding to APOL1 HREs. RT-qPCR analysis indicates that IFI16 selectively affects APOL1 expression, with a negligible impact on other hypoxia-responsive genes in podocytes. These findings highlight the unique contribution of IFI16 to hypoxia-driven APOL1 gene expression and suggest alternative IFI16-dependent mechanisms regulating APOL1 gene expression under hypoxic conditions.
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Affiliation(s)
- Richaundra K. Randle
- Department of Biomedical Sciences, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208, USA;
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, TN 37208, USA;
| | - Venkateswara Rao Amara
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, TN 37208, USA;
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education and Research, Hajipur 844102, Bihar, India
| | - Waldemar Popik
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, TN 37208, USA;
- Department of Internal Medicine, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA
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2
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Bao J, Ye J, Xu J, Liu S, Wang L, Li Z, Li Q, Liu F, He X, Zou H, Feng Y, Corpe C, Zhang X, Xu J, Zhu T, Wang J. Comprehensive RNA-seq reveals molecular changes in kidney malignancy among people living with HIV. MOLECULAR THERAPY - NUCLEIC ACIDS 2022; 29:91-101. [PMID: 35795483 PMCID: PMC9240952 DOI: 10.1016/j.omtn.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 06/05/2022] [Indexed: 11/30/2022]
Abstract
To heighten the awareness of kidney malignancy in patients with HIV infection to facilitate the early diagnosis of kidney cancer, the differentially expressed mRNAs were analyzed in this malignant tumor using RNA sequencing. We identified 2,962 protein-coding transcripts in HIV-associated kidney cancer. KISS1R, CAIX, and NPTX2 mRNA expression levels were specifically increased in HIV-associated kidney cancer while UMOD and TMEM213 mRNA were decreased in most cases based on real-time PCR analyses. These findings were similar to those noted for the general population with renal cell carcinoma. Immunohistochemical staining analysis also showed that a total of 18 malignant kidney cases among the people living with HIV (PLWH) exhibited positive staining for KISS1R and CAIX. Pathway analysis of the differentially expressed mRNAs in HIV-associated kidney cancer revealed that several key pathways were involved, including vascular endothelial growth factor-activated receptor activity, IgG binding, and lipopolysaccharide receptor activity. Altogether, our findings reveal the identified molecular changes in kidney malignancy, which may offer a helpful explanation for cancer progression and open up new therapeutic avenues that may decrease mortality after a cancer diagnosis among PLWH.
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Daneshpajouhnejad P, Kopp JB, Winkler CA, Rosenberg AZ. The evolving story of apolipoprotein L1 nephropathy: the end of the beginning. Nat Rev Nephrol 2022; 18:307-320. [PMID: 35217848 PMCID: PMC8877744 DOI: 10.1038/s41581-022-00538-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2022] [Indexed: 01/13/2023]
Abstract
Genetic coding variants in APOL1, which encodes apolipoprotein L1 (APOL1), were identified in 2010 and are relatively common among individuals of sub-Saharan African ancestry. Approximately 13% of African Americans carry two APOL1 risk alleles. These variants, termed G1 and G2, are a frequent cause of kidney disease — termed APOL1 nephropathy — that typically manifests as focal segmental glomerulosclerosis and the clinical syndrome of hypertension and arterionephrosclerosis. Cell culture studies suggest that APOL1 variants cause cell dysfunction through several processes, including alterations in cation channel activity, inflammasome activation, increased endoplasmic reticulum stress, activation of protein kinase R, mitochondrial dysfunction and disruption of APOL1 ubiquitinylation. Risk of APOL1 nephropathy is mostly confined to individuals with two APOL1 risk variants. However, only a minority of individuals with two APOL1 risk alleles develop kidney disease, suggesting the need for a ‘second hit’. The best recognized factor responsible for this ‘second hit’ is a chronic viral infection, particularly HIV-1, resulting in interferon-mediated activation of the APOL1 promoter, although most individuals with APOL1 nephropathy do not have an obvious cofactor. Current therapies for APOL1 nephropathies are not adequate to halt progression of chronic kidney disease, and new targeted molecular therapies are in clinical trials. This Review summarizes current understanding of the role of APOL1 variants in kidney disease. The authors discuss the genetics, protein structure and biological functions of APOL1 variants and provide an overview of promising therapeutic strategies. In contrast to other APOL family members, which are primarily intracellular, APOL1 contains a unique secretory signal peptide, resulting in its secretion into plasma. APOL1 renal risk alleles provide protection from African human trypanosomiasis but are a risk factor for progressive kidney disease in those carrying two risk alleles. APOL1 risk allele frequency is ~35% in the African American population in the United States, with ~13% of individuals having two risk alleles; the highest allele frequencies are found in West African populations and their descendants. Cell and mouse models implicate endolysosomal and mitochondrial dysfunction, altered ion channel activity, altered autophagy, and activation of protein kinase R in the pathogenesis of APOL1-associated kidney disease; however, the relevance of these injury pathways to human disease has not been resolved. APOL1 kidney disease tends to be progressive, and current standard therapies are generally ineffective; targeted therapeutic strategies hold the most promise.
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Affiliation(s)
- Parnaz Daneshpajouhnejad
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pathology, University of Pennsylvania Hospital, Philadelphia, PA, USA
| | | | - Cheryl A Winkler
- Basic Research Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Avi Z Rosenberg
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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4
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Ishida Y, Tian T, Brandt AL, Kelly AC, Shelton P, Roca AL, Novakofski J, Mateus-Pinilla NE. Association of chronic wasting disease susceptibility with prion protein variation in white-tailed deer ( Odocoileus virginianus). Prion 2021; 14:214-225. [PMID: 32835598 PMCID: PMC7518741 DOI: 10.1080/19336896.2020.1805288] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Chronic wasting disease (CWD) is caused by prions, infectious proteinaceous particles, PrPCWD. We sequenced the PRNP gene of 2,899 white-tailed deer (WTD) from Illinois and southern Wisconsin, finding 38 haplotypes. Haplotypes A, B, D, E, G and 10 others encoded Q95G96S100N103A123Q226, designated ‘PrP variant A.’ Haplotype C and five other haplotypes encoded PrP ‘variant C’ (Q95S96S100N103A123Q226). Haplotype F and three other haplotypes encoded PrP ‘variant F’ (H95G96S100N103A123Q226). The association of CWD with encoded PrP variants was examined in 2,537 tested WTD from counties with CWD. Relative to PrP variant A, CWD susceptibility was lower in deer with PrP variant C (OR = 0.26, p < 0.001), and even lower in deer with PrP variant F (OR = 0.10, p < 0.0001). Susceptibility to CWD was highest in deer with both chromosomes encoding PrP variant A, lower with one copy encoding PrP variant A (OR = 0.25, p < 0.0001) and lowest in deer without PrP variant A (OR = 0.07, p < 0.0001). There appeared to be incomplete dominance for haplotypes encoding PrP variant C in reducing CWD susceptibility. Deer with both chromosomes encoding PrP variant F (FF) or one encoding PrP variant C and the other F (CF) were all CWD negative. Our results suggest that an increased population frequency of PrP variants C or F and a reduced frequency of PrP variant A may reduce the risk of CWD infection. Understanding the population and geographic distribution of PRNP polymorphisms may be a useful tool in CWD management.
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Affiliation(s)
- Yasuko Ishida
- Department of Animal Sciences, University of Illinois at Urbana-Champaign , Urbana, IL, USA
| | - Ting Tian
- Illinois Natural History Survey-Prairie Research Institute, University of Illinois at Urbana-Champaign , Champaign, IL, USA.,School of Mathematics, Sun Yat-sen University , Guangzhou, People's Republic of China
| | - Adam L Brandt
- Illinois Natural History Survey-Prairie Research Institute, University of Illinois at Urbana-Champaign , Champaign, IL, USA.,Division of Natural Sciences, St. Norbert College , De Pere, WI, USA
| | - Amy C Kelly
- Illinois Natural History Survey-Prairie Research Institute, University of Illinois at Urbana-Champaign , Champaign, IL, USA.,Bayer U.S. - Crop Sciences Biotechnology Genomics and Data Science, BB4929-A , Chesterfield, MO, USA
| | - Paul Shelton
- Illinois Department of Natural Resources, Division of Wildlife Resources , Springfield, IL, USA
| | - Alfred L Roca
- Department of Animal Sciences, University of Illinois at Urbana-Champaign , Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign , Urbana, IL, USA
| | - Jan Novakofski
- Department of Animal Sciences, University of Illinois at Urbana-Champaign , Urbana, IL, USA.,Illinois Natural History Survey-Prairie Research Institute, University of Illinois at Urbana-Champaign , Champaign, IL, USA
| | - Nohra E Mateus-Pinilla
- Department of Animal Sciences, University of Illinois at Urbana-Champaign , Urbana, IL, USA.,Illinois Natural History Survey-Prairie Research Institute, University of Illinois at Urbana-Champaign , Champaign, IL, USA
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5
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Dhande IS, Doris PA. Genomics and Inflammation in Cardiovascular Disease. Compr Physiol 2021; 11:2433-2454. [PMID: 34570903 DOI: 10.1002/cphy.c200032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chronic cardiovascular diseases are associated with inflammatory responses within the blood vessels and end organs. The origin of this inflammation has not been certain, and neither is its relationship to disease clear. There is a need to determine whether this association is causal or coincidental to the processes leading to cardiovascular disease. These processes are themselves complex: many cardiovascular diseases arise in conjunction with the presence of sustained elevation of blood pressure. Inflammatory processes have been linked to hypertension, and causality has been suggested. Evidence of causality poses the difficult challenge of linking the integrated and multifaceted biology of blood pressure regulation with vascular function and complex elements of immune system function. These include both, innate and adaptive immunity, as well as interactions between the host immune system and the omnipresent microorganisms that are encountered in the environment and that colonize and exist in commensal relationship with the host. Progress has been made in this task and has drawn on experimental approaches in animals, much of which have focused on hypertension occurring with prolonged infusion of angiotensin II. These laboratory studies are complemented by studies that seek to inform disease mechanism by examining the genomic basis of heritable disease susceptibility in human populations. In this realm too, evidence has emerged that implicates genetic variation affecting immunity in disease pathogenesis. In this article, we survey the genetic and genomic evidence linking high blood pressure and its end-organ injuries to immune system function and examine evidence that genomic factors can influence disease risk. © 2021 American Physiological Society. Compr Physiol 11:1-22, 2021.
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Affiliation(s)
- Isha S Dhande
- Center for Human Genetics, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Peter A Doris
- Center for Human Genetics, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
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6
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Kruzel-Davila E, Sankofi BM, Kubi Amos-Abanyie E, Ghansah A, Nyarko A, Agyemang S, Awandare GA, Szwarcwort-Cohen M, Reiner-Benaim A, Hijazi B, Ulasi I, Raji YR, Boima V, Osafo C, May Adabayeri V, Matekole M, Olanrewaju TO, Ajayi S, Mamven M, Antwi S, Ademola AD, Plange-Rhule J, Arogundade F, Akyaw PA, Winkler CA, Salako BL, Ojo A, Skorecki K, Adu D. HIV Viremia Is Associated With APOL1 Variants and Reduced JC-Viruria. Front Med (Lausanne) 2021; 8:718300. [PMID: 34513880 PMCID: PMC8429812 DOI: 10.3389/fmed.2021.718300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/05/2021] [Indexed: 11/23/2022] Open
Abstract
Variants in the Apolipoprotein L1 (APOL1) gene (G1-rs60910145, rs73885319, G2-rs71785313) are common in Africans and in individuals of recent African ancestry and are associated with an increased risk of non-diabetic chronic kidney disease (CKD) and in particular of HIV associated nephropathy (HIVAN). In light of the significantly increased risk of HIVAN in carriers of two APOL1 risk alleles, a role in HIV infectivity has been postulated in the mechanism of APOL1 associated kidney disease. Herein, we aim to explore the association between HIV viremia and APOL1 genotype. In addition, we investigated interaction between BK and JC viruria, CKD and HIV viremia. A total of 199 persons living with HIV/AIDS (comprising 82 CKD cases and 117 controls) from among the participants in the ongoing Human Heredity and Health in Africa (H3Africa) Kidney Disease Research Network case control study have been recruited. The two APOL1 renal risk alleles (RRA) genotypes were associated with a higher risk of CKD (OR 12.6, 95% CI 3.89-40.8, p < 0.0001). Even a single APOL1 RRA was associated with CKD risk (OR 4.42, 95% CI 1.49-13.15, p = 0.007). The 2 APOL1 RRA genotypes were associated with an increased probability of having HIV viremia (OR 2.37 95% CI 1.0-5.63, p = 0.05). HIV viremia was associated with increased CKD risk (OR 7.45, 95% CI 1.66-33.35, P = 0.009) and with a significant reduction of JC virus urine shedding (OR 0.35, 95% CI 0.12-0.98, p = 0.046). In contrast to prior studies, JC viruria was not associated with CKD but was restricted in patients with HIV viremia, regardless of CKD status. These findings suggest a role of APOL1 variants in HIV infectivity and emphasize that JC viruria can serve as biomarker for innate immune system activation.
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Affiliation(s)
- Etty Kruzel-Davila
- Rappaport Faculty of Medicine, Technion Israel Institute of Technology, Haifa, Israel
- Nephrology Department, Rambam Health Care Campus, Haifa, Israel
| | - Barbara Mensah Sankofi
- College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Ernestine Kubi Amos-Abanyie
- College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Anita Ghansah
- College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Alexander Nyarko
- College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Seth Agyemang
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
- University of Ghana Medical School, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Gordon A. Awandare
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | | | | | - Basem Hijazi
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ifeoma Ulasi
- Department of Medicine, College of Health Sciences University of Nigeria, Enugu, Nigeria
| | | | - Vincent Boima
- University of Ghana Medical School, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Charlotte Osafo
- University of Ghana Medical School, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Victoria May Adabayeri
- University of Ghana Medical School, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Michael Matekole
- University of Ghana Medical School, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Timothy O. Olanrewaju
- Department of Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Samuel Ajayi
- Department of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Manmak Mamven
- Department of Medicine, University of Abuja, Abuja, Nigeria
| | - Sampson Antwi
- Department of Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Jacob Plange-Rhule
- Department of Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Priscilla Abena Akyaw
- College of Health Sciences, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Cheryl A. Winkler
- Department of Medicine, Frederick National Laboratory for Cancer Research (NIH), Frederick, MD, United States
| | | | - Akinlolu Ojo
- School of Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Karl Skorecki
- Rappaport Faculty of Medicine, Technion Israel Institute of Technology, Haifa, Israel
- Rambam Health Care Campus, Haifa, Israel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Dwomoa Adu
- University of Ghana Medical School, College of Health Sciences, University of Ghana, Accra, Ghana
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7
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An P, Sezgin E, Kirk GD, Duggal P, Binns-Roemer E, Nelson G, Limou S, Van Natta ML, Jabs DA, Estrella M, Kopp JB, Winkler CA. APOL1 variant alleles associate with reduced risk for opportunistic infections in HIV infection. Commun Biol 2021; 4:284. [PMID: 33674766 PMCID: PMC7977062 DOI: 10.1038/s42003-021-01812-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/08/2021] [Indexed: 11/10/2022] Open
Abstract
Apolipoprotein L1 (APOL1), an innate immune factor against African trypanosoma brucei, inhibits HIV-1 in vitro. The impact of APOL1 G1-G2 variants on HIV-1-associated opportunistic infections (OIs) is unknown. Here, we report findings from a metaanalysis of four HIV/AIDS prospective cohorts (ALIVE, LSOCA, MACS, and WIHS) including 2066 African American participants. Using a global test combining all four cohorts, carriage of two APOL1 variant alleles is associated with a 50% reduction in odds of OI (combined OR 0.50, 95% CI 0.33-0.76). Subgroup analysis of OI etiological categories (viral, parasitic, fungal and Mycobacterial) suggests the possibility of specific protection from fungal infections (OR 0.54. 95% CI 0.32-0.93; PBonferroni corrected = 0.08). We observe an association of APOL1 variant alleles with host protection against OI in HIV-positive individuals. The study suggests a broader role of APOL1 variant alleles in innate immunity in vivo.
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Affiliation(s)
- Ping An
- Basic Research Laboratory, Molecular Genetic Epidemiology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
| | - Efe Sezgin
- Basic Research Laboratory, Molecular Genetic Epidemiology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
- Department of Epidemiology, the Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Laboratory of Nutrigenomics and Epidemiology, Izmir Institute of Technology, Izmir, Turkey
| | - Gregory D Kirk
- Department of Epidemiology, the Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Department of Medicine, the Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Priya Duggal
- Department of Epidemiology, the Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Elizabeth Binns-Roemer
- Basic Research Laboratory, Molecular Genetic Epidemiology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - George Nelson
- Center for Cancer Research Informatics Core, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Sophie Limou
- Basic Research Laboratory, Molecular Genetic Epidemiology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
- CRTI UMR1064, Inserm, Université de Nantes & ITUN, CHU Nantes, Nantes, France
- Ecole Centrale de Nantes, Nantes, France
| | - Mark L Van Natta
- Department of Epidemiology, the Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Douglas A Jabs
- Department of Epidemiology, the Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Department of Ophthalmology, the Wilmer Eye Institute, the Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michelle Estrella
- Kidney Health Research Collaborative, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
- San Francisco VA Health Care System, San Francisco, CA, USA
| | - Jeffrey B Kopp
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Cheryl A Winkler
- Basic Research Laboratory, Molecular Genetic Epidemiology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
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8
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Pays E. The function of apolipoproteins L (APOLs): relevance for kidney disease, neurotransmission disorders, cancer and viral infection. FEBS J 2021; 288:360-381. [PMID: 32530132 PMCID: PMC7891394 DOI: 10.1111/febs.15444] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/24/2020] [Accepted: 06/03/2020] [Indexed: 12/17/2022]
Abstract
The discovery that apolipoprotein L1 (APOL1) is the trypanolytic factor of human serum raised interest about the function of APOLs, especially following the unexpected finding that in addition to their protective action against sleeping sickness, APOL1 C-terminal variants also cause kidney disease. Based on the analysis of the structure and trypanolytic activity of APOL1, it was proposed that APOLs could function as ion channels of intracellular membranes and be involved in mechanisms triggering programmed cell death. In this review, the recent finding that APOL1 and APOL3 inversely control the synthesis of phosphatidylinositol-4-phosphate (PI(4)P) by the Golgi PI(4)-kinase IIIB (PI4KB) is commented. APOL3 promotes Ca2+ -dependent activation of PI4KB, but due to their increased interaction with APOL3, APOL1 C-terminal variants can inactivate APOL3, leading to reduction of Golgi PI(4)P synthesis. The impact of APOLs on several pathological processes that depend on Golgi PI(4)P levels is discussed. I propose that through their effect on PI4KB activity, APOLs control not only actomyosin activities related to vesicular trafficking, but also the generation and elongation of autophagosomes induced by inflammation.
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Affiliation(s)
- Etienne Pays
- Laboratory of Molecular ParasitologyIBMMUniversité Libre de BruxellesGosseliesBelgium
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9
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Abstract
Podocytopathies are kidney diseases in which direct or indirect podocyte injury drives proteinuria or nephrotic syndrome. In children and young adults, genetic variants in >50 podocyte-expressed genes, syndromal non-podocyte-specific genes and phenocopies with other underlying genetic abnormalities cause podocytopathies associated with steroid-resistant nephrotic syndrome or severe proteinuria. A variety of genetic variants likely contribute to disease development. Among genes with non-Mendelian inheritance, variants in APOL1 have the largest effect size. In addition to genetic variants, environmental triggers such as immune-related, infection-related, toxic and haemodynamic factors and obesity are also important causes of podocyte injury and frequently combine to cause various degrees of proteinuria in children and adults. Typical manifestations on kidney biopsy are minimal change lesions and focal segmental glomerulosclerosis lesions. Standard treatment for primary podocytopathies manifesting with focal segmental glomerulosclerosis lesions includes glucocorticoids and other immunosuppressive drugs; individuals not responding with a resolution of proteinuria have a poor renal prognosis. Renin-angiotensin system antagonists help to control proteinuria and slow the progression of fibrosis. Symptomatic management may include the use of diuretics, statins, infection prophylaxis and anticoagulation. This Primer discusses a shift in paradigm from patient stratification based on kidney biopsy findings towards personalized management based on clinical, morphological and genetic data as well as pathophysiological understanding.
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10
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Chaudhary NS, Moore JX, Zakai NA, Judd SE, Naik RP, Limou S, Cushman M, Lange LA, Wang HE, Winkler CA, Irvin MR, Kopp JB, Gutiérrez OM. APOL1 Nephropathy Risk Alleles and Risk of Sepsis in Blacks. Clin J Am Soc Nephrol 2019; 14:1733-1740. [PMID: 31704668 PMCID: PMC6895473 DOI: 10.2215/cjn.04490419] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 09/30/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND OBJECTIVES apo L1 (APOL1) nephropathy risk alleles are associated with CKD in blacks. Although APOL1 has innate immune functions, little is known about the association of APOL1 genotypes with risk of infectious outcomes, such as sepsis. The objective of this study was to examine the associations of APOL1 nephropathy risk alleles with risk of sepsis in black adults. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We assessed the association of APOL1 risk alleles with incident sepsis in 10,366 black participants of the Reasons for Geographic and Racial Differences in Stroke study enrolled between 2003 and 2007 with follow-up through December 31, 2012. In Cox models adjusted for demographics, comorbid conditions, and principal components ancestry, we examined the association of APOL1 risk alleles with incident sepsis using recessive (comparing zero or one versus two risk alleles), dominant (zero versus one or two risk alleles), and additive genetic models. We also examined models stratified by diabetes and CKD status. RESULTS A total of 1320 (13%) participants had two APOL1 risk alleles, 4719 (46%) had one risk allele, and 4327 (42%) participants had zero risk alleles. A total of 306 sepsis events occurred over a median 6.5 years (interquartile range, 4.5-8.1). There were no statistically significant associations of APOL1 genotype with sepsis risk under recessive genetic models. APOL1 genotypes were associated with sepsis risk under dominant (hazard ratio, 1.55; 95% confidence interval, 1.13 to 2.11) and additive (hazard ratio per variant allele copy, 1.25; 95% confidence interval, 1.02 to 1.53) genetic models adjusted for covariates and ancestry. These associations did not vary by diabetes or CKD status (Pinteraction>0.10 for both). CONCLUSIONS In community-dwelling black adults, carriage of APOL1 nephropathy risk alleles are common and associated with higher risk of sepsis.
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Affiliation(s)
| | - Justin X. Moore
- Departments of Epidemiology
- Division of Public Health Sciences, Department of Surgery, Washington University, St. Louis, Missouri
| | - Neil A. Zakai
- Departments of Medicine and Pathology and Laboratory Medicine, Larner College of Medicine, University of Vermont, Burlington, Vermont
| | | | - Rakhi P. Naik
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Sophie Limou
- Nantes University, French National Institute of Health and Medical Research, Center for Research in Transplantation and Immunology, Nantes, France
| | - Mary Cushman
- Departments of Medicine and Pathology and Laboratory Medicine, Larner College of Medicine, University of Vermont, Burlington, Vermont
| | - Leslie A. Lange
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Henry E. Wang
- Department of Emergency Medicine, University of Texas Health Science Center at Houston, Houston, Texas
| | - Cheryl A. Winkler
- Basic Research Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland; and
| | | | - Jeffrey B. Kopp
- Intramural Research Program, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Orlando M. Gutiérrez
- Departments of Epidemiology
- Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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Abstract
The apolipoprotein L1 (APOL1) gene is unique to humans and gorillas and appeared ~33 million years ago. Since the majority of the mammals do not carry APOL1, it seems to be dispensable for kidney function. APOL1 renal risk variants (RRVs; G1 and G2) are associated with the development as well as progression of chronic kidney diseases (CKDs) at higher rates in populations with African ancestry. Cellular expression of two APOL1 RRVs has been demonstrated to induce cytotoxicity, including necrosis, apoptosis, and pyroptosis, in several cell types including podocytes; mechanistically, these toxicities were attributed to lysosomal swelling, K+ depletion, mitochondrial dysfunction, autophagy blockade, protein kinase receptor activation, ubiquitin D degradation, and endoplasmic reticulum stress; notably, these effects were found to be dose dependent and occurred only in overtly APOL1 RRV-expressing cells. However, cellular protein expressions as well as circulating blood levels of APOL1 RRVs were not elevated in patients suffering from APOL1 RRV-associated CKDs. Therefore, the question arises as to whether it is gain or loss of function on the part of APOL1 RRVs contributing to kidney cell injury. The question seems to be more pertinent after the recognition of the role of APOL1 nonrisk (G0) in the transition of parietal epithelial cells and preservation of the podocyte molecular phenotype through modulation of the APOL1-miR-193a axis. With this background, the present review analyzed the available literature in terms of the known function of APOL1 nonrisk and how the loss of these functions could have contributed to two APOL1 RRV-associated CKDs.
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Affiliation(s)
- Vinod Kumar
- Institute of Molecular Medicine, Feinstein Institute for Medical Research and Department of Medicine, Zucker School of Medicine at Hofstra-Northwell, Hempstead, New York
| | - Pravin C Singhal
- Institute of Molecular Medicine, Feinstein Institute for Medical Research and Department of Medicine, Zucker School of Medicine at Hofstra-Northwell, Hempstead, New York
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