R01DK126666

Mechanistic and Metabolomic Underpinnings of ALDH1L1 Polymorphisms in the Regulation of Glycine Metabolism

ALDH1L1, a common enzyme in folate metabolism, converts 10-formyltetrahydrofolate (10-formyl-THF) to tetrahydrofolate (THF). This reaction is known to regulate the de novo purine biosynthesis and folate-dependent homocysteine re-methylation cycle. It could also play a key role in controlling the flux of one-carbon groups to anabolic pathways.

In support of the role in the regulation of folate metabolism, we have recently shown that the loss of the ALDH1L1 gene in knockout mice causes functional folate deficiency, even when the mice had sufficient folate intake. Analysis of ALDH1L1 knockout mice also showed that the enzyme is the main regulator of glycine metabolism in the liver: KO mice have lower levels of glycine and glycine conjugates, indicating that the enzyme is involved in the folate-dependent synthesis of glycine from serine.

We have further reported that human ALDH1L1 has six common non-synonymous exonic SNPs at the polymorphic loci rs3796191, rs2886059, rs9282691, rs2276724, rs1127717, and rs4646750, with the occurrence of haplotypes associated with these SNPs being remarkably different between ethnic populations. Our analysis of an established cohort of Hispanic children, Viva La Familia, has shown a significant reduction of serum glycine and an increase in serine/glycine ratio in children with rs2276724 and rs3796191, indicating deregulation of serine to glycine conversion and recapitulating our mouse findings. ALDH1L1 non-synonymous SNPs were also associated with markers of metabolic stress and adiposity in this cohort.

Based on our findings, we hypothesize that non-synonymous ALDH1L1 SNPs produce enzyme variants with altered catalytic activity and/or stability that affects their ability to metabolize 10-formyl-THF and thus deregulates glycine metabolism. Accordingly, individuals with specific haplotypes have different ratios of THF/10-formyl-THF and serine/glycine, and altered levels of glycine and its conjugates, with perturbations in the metabotype representing a signature of metabolic health.

This proposal will address the question of how haplotype-specific ALDH1L1 variants affect folate metabolism and the overall cellular metabotype, and how the haplotype-specific effect is modified by folate supplementation, by pursuing the following specific aims.

Aim 1: Functionally characterize the ALDH1L1 enzyme variants from common human haplotypes.
Aim 2: Determine the impact of major ALDH1L1 haplotypes on cellular metabolism and haplotype-specific responses to various folate supplementations.
Aim 3: Link ALDH1L1 haplotypes to the folate-dependent regulation of glycine metabolism and health outcomes in humans.

ALDH1L1 variants are very common in different populations, but their role in folate homeostasis and in the etiology of metabolic disease is largely unexplored. It is expected that ALDH1L1 haplotypes differently mediate the metabolic response to dietary folate that might require adjustments of folate intake for individuals bearing certain ALDH1L1 SNPs. By filling this knowledge gap, the proposed research will provide mechanistic insight into the metabolic regulation by ALDH1L1 SNPs and will lay ground for the evaluation of population-specific ALDH1L1 haplotypes as a disease risk factor.

University Of North Carolina At Chapel Hill

(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.

93.847 - Diabetes, Digestive, and Kidney Diseases Extramural Research

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

Kannapolis, North Carolina 280813379 United States

Single Zip Code

NIH Research Project Grant (Parent R01 Clinical Trial Not Allowed) (PA-20-185)

Amendment Since initial award the total obligations have increased 412% from $657,001 to $3,366,211.