R01DK127139

Elucidating Genetic and Environmental Second Hits in Racial and Ethnic Minorities with APOL1 High-Risk Genotypes - Project Summary

This is an application by an early stage investigator who has the long-term objective of studying determinants of racial and ethnic disparities in kidney disease. Risk variants in the apolipoprotein L1 (APOL1) gene on chromosome 22 are common in persons of African ancestry (African Americans and Afro-Caribbean Hispanic Americans) and are one of the most powerful disease variants identified to date in terms of frequency and effect size. This is an important discovery for kidney disease and has furthered our understanding of racial/ethnic disparities in kidney disease.

There are efforts underway to incorporate APOL1 genetic testing in clinical settings, including in pre-transplant evaluation, and targeted therapies are on the horizon. However, the presence of two risk variants (i.e., the APOL1 high-risk genotypes, seen in up to 14% of African Americans and 4% of Afro-Caribbean Hispanic Americans) does not lead to overt kidney disease in all individuals. This incomplete penetrance indicates a major role of either genetic or environmental modifiers, i.e., 'second hits'.

Although some genetic modifiers have been discovered, previous studies have been hampered by lack of sample sizes due to underrepresentation of minorities. There are also strong associations between air pollution, adverse neighborhood environment (including walkability and poverty), and podocyte toxic heavy metals (arsenic, cadmium, and mercury) with kidney disease, and racial/ethnic minorities are disproportionately exposed to these environmental risk factors.

We propose a robust research strategy leveraging several large datasets/cohorts to comprehensively investigate the genetic and environmental 'second-hits' for the APOL1-kidney disease association through the following specific aims:

Aim 1: To identify and replicate SNPs that modify the association of the APOL1 high-risk genotypes with kidney disease. Using genetic and clinical data on ~70,000 minority individuals (~5,400 with APOL1 high-risk genotypes), we will investigate SNPs modifying the association between APOL1 high-risk genotype and kidney disease. We will then perform replication of the top performing hits in ~25,000 independent individuals (~5,000 with APOL1 high-risk genotypes).

Aim 2: To assess the interaction of air pollution (particulate matter <2.5 μg or PM2.5) and adverse measures of neighborhood walkability/poverty with APOL1 high-risk for kidney disease. We will use geographically diverse studies: Biome Biobank, Jackson Heart Study, and Reasons for Geographic and Racial Differences in Stroke (REGARDS) in ~40,000 individuals (~3,600 with APOL1 high-risk genotypes).

Aim 3: To explore the interaction between urine levels of arsenic, cadmium, and mercury with APOL1 high-risk genotypes for kidney disease in a case-control study from REGARDS (N=2,332). Additionally, in exploratory analyses, we will assess whether soluble urokinase-type plasminogen activator receptor (SUPAR) levels - an inflammatory APOL1 modifier - affect this interaction.

This proposal will lead to critical insights on genetic and environmental 'second hits' for APOL1 and improved understanding of racial/ethnic disparities in kidney disease.

Icahn School Of Medicine At Mount Sinai

(1) TO PROMOTE EXTRAMURAL BASIC AND CLINICAL BIOMEDICAL RESEARCH THAT IMPROVES THE UNDERSTANDING OF THE MECHANISMS UNDERLYING DISEASE AND LEADS TO IMPROVED PREVENTIONS, DIAGNOSIS, AND TREATMENT OF DIABETES, DIGESTIVE, AND KIDNEY DISEASES. PROGRAMMATIC AREAS WITHIN THE NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES INCLUDE DIABETES, DIGESTIVE, ENDOCRINE, HEMATOLOGIC, LIVER, METABOLIC, NEPHROLOGIC, NUTRITION, OBESITY, AND UROLOGIC DISEASES. SPECIFIC PROGRAMS AREAS OF INTEREST INCLUDE THE FOLLOWING: (A) FOR DIABETES, ENDOCRINE, AND METABOLIC DISEASES AREAS: FUNDAMENTAL AND CLINICAL STUDIES INCLUDING THE ETIOLOGY, PATHOGENESIS, PREVENTION, DIAGNOSIS, TREATMENT AND CURE OF DIABETES MELLITUS AND ITS COMPLICATIONS, NORMAL AND ABNORMAL FUNCTION OF THE PITUITARY, THYROID, PARATHYROID, ADRENAL, AND OTHER HORMONE SECRETING GLANDS, HORMONAL REGULATION OF BONE, ADIPOSE TISSUE, AND LIVER, ON FUNDAMENTAL ASPECTS OF SIGNAL TRANSDUCTION, INCLUDING THE ACTION OF HORMONES, COREGULATORS, AND CHROMATIN REMODELING PROTEINS, HORMONE BIOSYNTHESIS, SECRETION, METABOLISM, AND BINDING, AND ON HORMONAL REGULATION OF GENE EXPRESSION AND THE ROLE(S) OF SELECTIVE RECEPTOR MODULATORS AS PARTIAL AGONISTS OR ANTAGONISTS OF HORMONE ACTION, AND FUNDAMENTAL STUDIES RELEVANT TO METABOLIC DISORDERS INCLUDING MEMBRANE STRUCTURE, FUNCTION, AND TRANSPORT PHENOMENA AND ENZYME BIOSYNTHESIS, AND BASIC AND CLINICAL STUDIES ON THE ETIOLOGY, PATHOGENESIS, PREVENTION, AND TREATMENT OF INHERITED METABOLIC DISORDERS (SUCH AS CYSTIC FIBROSIS). (B) FOR DIGESTIVE DISEASE AND NUTRITION AREAS: GENETICS AND GENOMICS OF THE GI TRACT AND ITS DISEASES, GENETICS AND GENOMICS OF LIVER/PANCREAS AND DISEASES, GENETICS AND GENOMICS OF NUTRITION, GENETICS AND GENOMICS OF OBESITY, BARIATRIC SURGERY, CLINICAL NUTRITION RESEARCH, CLINICAL OBESITY RESEARCH, COMPLICATIONS OF CHRONIC LIVER DISEASE, FATTY LIVER DISEASE, GENETIC LIVER DISEASE, HIV AND LIVER, CELL INJURY, REPAIR, FIBROSIS AND INFLAMMATION IN THE LIVER, LIVER CANCER, LIVER TRANSPLANTATION, PEDIATRIC LIVER DISEASE, VIRAL HEPATITIS AND INFECTIOUS DISEASES, GASTROINTESTINAL AND NUTRITION EFFECTS OF AIDS, GASTROINTESTINAL MUCOSAL AND IMMUNOLOGY, GASTROINTESTINAL MOTILITY, BASIC NEUROGASTROENTEROLOGY, GASTROINTESTINAL DEVELOPMENT, GASTROINTESTINAL EPITHELIAL BIOLOGY, GASTROINTESTINAL INFLAMMATION, DIGESTIVE DISEASES EPIDEMIOLOGY AND DATA SYSTEMS, NUTRITIONAL EPIDEMIOLOGY AND DATA SYSTEMS, AUTOIMMUNE LIVER DISEASE, BILE, BILIRUBIN AND CHOLESTASIS, BIOENGINEERING AND BIOTECHNOLOGY RELATED TO DIGESTIVE DISEASES, LIVER, NUTRITION AND OBESITY, CELL AND MOLECULAR BIOLOGY OF THE LIVER, DEVELOPMENTAL BIOLOGY AND REGENERATION, DRUG-INDUCED LIVER DISEASE, GALLBLADDER DISEASE AND BILIARY DISEASES, EXOCRINE PANCREAS BIOLOGY AND DISEASES, GASTROINTESTINAL NEUROENDOCRINOLOGY, GASTROINTESTINAL TRANSPORT AND ABSORPTION, NUTRIENT METABOLISM, PEDIATRIC CLINICAL OBESITY, CLINICAL TRIALS IN DIGESTIVE DISEASES, LIVER CLINICAL TRIALS, OBESITY PREVENTION AND TREATMENT, AND OBESITY AND EATING DISORDERS. (C) FOR KIDNEY, UROLOGIC AND HEMATOLOGIC DISEASES AREAS: STUDIES OF THE DEVELOPMENT, PHYSIOLOGY, AND CELL BIOLOGY OF THE KIDNEY, PATHOPHYSIOLOGY OF THE KIDNEY, GENETICS OF KIDNEY DISORDERS, IMMUNE MECHANISMS OF KIDNEY DISEASE, KIDNEY DISEASE AS A COMPLICATION OF DIABETES, EFFECTS OF DRUGS, NEPHROTOXINS AND ENVIRONMENTAL TOXINS ON THE KIDNEY, MECHANISMS OF KIDNEY INJURY REPAIR, IMPROVED DIAGNOSIS, PREVENTION AND TREATMENT OF CHRONIC KIDNEY DISEASE AND END-STAGE RENAL DISEASE, IMPROVED APPROACHES TO MAINTENANCE DIALYSIS THERAPIES, BASIC STUDIES OF LOWER URINARY TRACT CELL BIOLOGY, DEVELOPMENT, PHYSIOLOGY, AND PATHOPHYSIOLOGY, CLINICAL STUDIES OF BLADDER DYSFUNCTION, INCONTINENCE, PYELONEPHRITIS, INTERSTITIAL CYSTITIS, BENIGN PROSTATIC HYPERPLASIA, UROLITHIASIS, AND VESICOURETERAL REFLUX, DEVELOPMENT OF NOVEL DIAGNOSTIC TOOLS AND IMPROVED THERAPIES, INCLUDING TISSUE ENGINEERING STRATEGIES, FOR UROLOGIC DISORDERS,RESEARCH ON HEMATOPOIETIC CELL DIFFERENTIATION, METABOLISM OF IRON OVERLOAD AND DEFICIENCY, STRUCTURE, BIOSYNTHESIS AND GENETIC REGULATION OF HEMOGLOBIN, AS WELL AS RESEARCH ON THE ETIOLOGY, PATHOGENESIS, AND THERAPEUTIC MODALITIES FOR THE ANEMIA OF INFLAMMATION AND CHRONIC DISEASES. (2) TO ENCOURAGE BASIC AND CLINICAL RESEARCH TRAINING AND CAREER DEVELOPMENT OF SCIENTISTS DURING THE EARLY STAGES OF THEIR CAREERS. THE RUTH L. KIRSCHSTEIN NATIONAL RESEARCH SERVICE AWARD (NRSA) FUNDS BASIC AND CLINICAL RESEARCH TRAINING, SUPPORT FOR CAREER DEVELOPMENT, AND THE TRANSITION FROM POSTDOCTORAL BIOMEDICAL RESEARCH TRAINING TO INDEPENDENT RESEARCH RELATED TO DIABETES, DIGESTIVE, ENDOCRINE, HEMATOLOGIC, LIVER, METABOLIC, NEPHROLOGIC, NUTRITION, OBESITY, AND UROLOGIC DISEASES. (3) TO EXPAND AND IMPROVE THE SMALL BUSINESS INNOVATION RESEARCH (SBIR) PROGRAM. THE SBIR PROGRAM AIMS TO INCREASE AND FACILITATE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, TO ENHANCE SMALL BUSINESS PARTICIPATION IN FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. (4) TO UTILIZE THE SMALL BUSINESS TECHNOLOGY TRANSFER (STTR) PROGRAM. THE STTR PROGRAM INTENDS TO STIMULATE AND FOSTER SCIENTIFIC AND TECHNOLOGICAL INNOVATION THROUGH COOPERATIVE RESEARCH AND DEVELOPMENT CARRIED OUT BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO FOSTER TECHNOLOGY TRANSFER BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO INCREASE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION.

93.310 - Trans-NIH Research Support

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) [HHS - NIH]

National Institute of Allergy and Infectious Diseases (NIAID) [HHS - NIH]

New York United States

State-Wide

Administrative Supplements to Existing NIH Grants and Cooperative Agreements (Parent Admin Supp Clinical Trial Optional) (PA-20-272)

COVID-19 $662,080 (16%) percent of this Project Grant was funded by COVID-19 emergency acts including the American Rescue Plan Act of 2021.
Amendment Since initial award the End Date has been shortened from 11/30/25 to 05/31/23 and the total obligations have increased 421% from $775,497 to $4,038,926.