Document text
Principal Investigator: Sandeep K Mallipattu
Organization: NORTHPORT VA MEDICAL CENTER
Fiscal Year: 2024
Funding agency: Veterans Affairs
Chronic kidney disease (CKD) is a leading risk factor for cardiovascular disease, with a
disproportionate burden on U.S. Veterans. Recent data demonstrates that acute kidney injury (AKI), despite
initial renal recovery, is a major risk factor for CKD. The proximal tubule (PT) is the primary target in AKI due to
its high susceptibility to ischemia and DNA-damaging nephrotoxins such as chemotherapeutic agents.
Damaged PT cells dedifferentiate, and initially undergo cell cycle arrest, predominantly at the G2/M checkpoint.
This cell cycle arrest may allow repair of DNA damage caused by reactive oxygen species secondary to
mitochondrial damage or directly by DNA-damaging toxins. Sustained cell cycle arrest is associated with a
switch to secretion of pro-fibrotic signaling molecules, inducing resident fibroblasts to proliferate and
differentiate to myofibroblasts, beginning the transition to a fibrotic injury. PT cells also undergo metabolic
reprograming, with severe downregulation of fatty acid b-oxidation (FAO), and limited compensation by
anerobic glycolysis. While restoring FAO either by overexpressing Ppara or by using a peroxisome proliferator
activated receptor alpha (PPARa) agonist attenuates AKI and CKD in murine models, this has not translated to
use in clinical AKI, suggesting additional factors are required to mitigate the progression from AKI to CKD.
Krüppel-Like Factor 15 (KLF15) is a kidney-enriched transcription factor, involved in a diverse range of
cellular processes, including cell differentiation and FAO. In the initial funding period of the VA Merit, we
demonstrated the salutary role of KLF15 in glomerular disease leading to a composition-of-matter IP on KLF15
agonists by the Veterans Affairs. During this initial period, we also identified that KLF15 is highly expressed in
differentiated PT cells, but is significantly reduced in murine models of PT injury. Utilizing a murine model of
PT-specific injury secondary to DNA damage, we observed that PT-specific knockdown of Klf15 exacerbated
AKI as well as CKD. PT-specific knockdown of Klf15 also increased pathways involving cell cycle arrest,
oxidative stress, pro-fibrotic signaling and a decrease in pathways utilizing FA for the generation of acetyl-CoA,
a central metabolic intermediate in macromolecule biosynthesis and energy production. We also observed an
enrichment of genes critical for FA utilization with putative and proximal KLF15- and PPARa-binding sites,
suggesting potential KLF15-PPARa co-operativity in the regulation of FA utilization. In addition, we
demonstrated a significant increase in glycerolipid synthesis pathways and lipid droplet formation in the setting
of suppressed FAO, suggesting a potential compensatory mechanism post-DNA damage. KLF15 expression
was also associated with PPARA expression in human kidney biopsies with and without CKD. In addition,
multivariate regression analysis demonstrated that a decrease in KLF15 expression was independently
associated with eGFR decline, suggesting that the loss of KLF15 might be a key driver of PT injury.
Based on these preliminary data and strong scientific rigor of prior research, we hypothesize that
KLF15-PPARa co-operativity drives the utilization of excess free fatty acids for acetyl-CoA and glycerolipid
synthesis to prevent maladaptive PT repair post-DNA damage. We propose to test this hypothesis by (1)
determining the mechanism by which KLF15-PPARa co-operativity restores PT metabolism after PT injury
secondary to DNA-damage and (2) to investigate the requisite role of KLF15-PPARa in PT injury secondary to
DNA-damage. This proposal will address a current gap in the field by investigating the mechanisms mediating
transcriptional regulation of FA utilization in the PT cells post-DNA damage. The long-term goal of our project
is to demonstrate that the combination of KLF15 and PPARa agonists is a novel therapeutic strategy to
mitigate PT injury post-DNA damage. Identification of novel targets for the treatment of AKI is of major interest
to the VA, given the high burden of CKD among U.S. Veterans.
Terms: <1,2-diacylglycerol><Acetyl CoA><Acetyl Coenzyme A><Active Oxygen><Acute Renal Failure with Renal Papillary Necrosis><Agonist><American><Anabolism><Aristolochic Acids><Attenuated><Basal Transcription Factor><Basal transcription factor genes><Binding Sites><CDDP><Cardiovascular Diseases><Cell Body><Cell Communication and Signaling><Cell Cycle Arrest><Cell Differentiation><Cell Differentiation process><Cell Function><Cell Physiology><Cell Process><Cell Signaling><Cells><Cellular Function><Cellular Physiology><Cellular Process><Cellular injury><ChIP Sequencing><ChIP-seq><ChIPseq><Chronic Kidney Failure><Chronic Renal Disease><Chronic Renal Failure><Cis-diammine-dichloroplatinum><Cis-diamminedichloridoplatinum><Cis-diamminedichloro Platinum (II)><Cis-dichloroammine Platinum (II)><Cis-platinous Diamine Dichloride><Cis-platinum II><Cis-platinum II Diamine Dichloride><Cisplatin><Cisplatina><Cisplatinum><Clinical><Combining Site><Compensation><Cysplatyna><DNA Damage><DNA Damage Repair><DNA Injury><DNA Repair><Data><Diacylglycerols><Dichlorodiammineplatinum><Diglycerides><Down-Regulation><Fatty Acids><Fibroblasts><Free Fatty Acids><Funding><General Population><General Public><General Transcription Factor Gene><General Transcription Factors><Generations><Genes><Glomerular disease><Glycolysis><Goals><Hexadecanoates><Human><Injury><Injury to Kidney><Intermediary Metabolism><Intracellular Communication and Signaling><Ischemia><Kidney><Kidney Urinary System><Lipids><Mediating><Metabolic><Metabolic Pathway><Metabolic Processes><Metabolism><Mice><Mice Mammals><Mitochondria><Modern Man><Murine><Mus><Myofibroblast><Nonesterified Fatty Acids><Organoids><Oxidative Stress><Oxygen Radicals><PPAR alpha><PPAR-α><PPARalpha><PPARα><Palmitates><Pathway interactions><Peroxisome Proliferator-Activated Receptor alpha><Peroxisome Proliferator-Activated Receptor α><Peyrone's Chloride><Peyrone's Salt><Phase><Platinum Diamminodichloride><Pre-Clinical Model><Preclinical Models><Predisposition><Prevalence><Pro-Oxidants><Production><Profibrotic factor><Profibrotic signal><Proliferating><RNA Seq><RNA sequencing><RNAseq><Reactive Oxygen Species><Reactive Site><Recovery><Regression Analyses><Regression Analysis><Regression Diagnostics><Regulation><Renal Glomerular Diseases and Syndromes><Renal glomerular disease><Renal glomerular disease or syndrome><Renal glomerular disorder><Renal glomerular syndrome><Research><Respiration><Risk Factors><Role><S-acetate Coenzyme A><Secondary to><Signal Transduction><Signal Transduction Systems><Signaling><Signaling Molecule><Single-Nucleus Sequencing><Source><Statistical Regression><Subcellular Process><Susceptibility><Testing><Therapeutic><Toxin><Transcription Factor Proto-Oncogene><Transcription Regulation><Transcription factor genes><Transcriptional Control><Transcriptional Regulation><Triacylglycerol><Triglycerides><United States Department of Veterans Affairs><United States Veterans Administration><Unscheduled DNA Synthesis><Veterans><Veterans Administration><Veterans Affairs><acute kidney injury><attenuate><attenuates><biological signal transduction><biosynthesis><cardiovascular disorder><cardiovascular risk><cardiovascular risk factor><cell damage><cell dedifferentiation><cell injury><cellular damage><cellular differentiation><chemotherapeutic agent><chromatin immunoprecipitation-sequencing><chronic kidney disease><cis dichlorodiammineplatinum><cis platinum compound><cis-Diaminedichloroplatinum><cis-Diamminedichloroplatinum><cis-Diamminedichloroplatinum(II)><cis-Dichlorodiammineplatinum(II)><cis-Platinum><clinical relevance><clinically relevant><damage to cells><diacylglycerol><diglyceride><extracellular><in silico><inducible expression><inducible gene expression><injuries><injury to cells><interest><kidney biopsy><kidney injury><knock-down><knockdown><macromolecule><mitochondrial><mouse model><murine model><new therapeutic approach><new therapeutic intervention><new therapeutic strategies><new therapy approaches><new treatment approach><new treatment strategy><novel><novel therapeutic approach><novel therapeutic intervention><novel therapeutic strategies><novel therapy approach><overexpress><overexpression><oxidation><pathway><peroxidation><prevent><preventing><renal><renal biopsy><renal injury><repair><repaired><respiratory mechanism><sNuc-Seq><single nucleus RNA-sequencing><single nucleus seq><single-nucleus RNA-seq><snRNA sequencing><snRNA-seq><social role><transcription factor><transcriptome sequencing><transcriptomic sequencing>