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Principal Investigator: SEUNGHEE CHA
Organization: UNIVERSITY OF FLORIDA
Fiscal Year: 2024
Award: $598,932
Funding agency: National Institute of Dental and Craniofacial Research
ABSTRACT
Through our multidisciplinary clinical and research collaboration, we have established a rare cohort of children and
adolescents who fulfilled the 2016 adult Sjögren’s disease (SjD) criteria (namely, cSjD for childhood Sjögren’s
disease). Since autoimmune SjD typically affects elderly females, whether cSjD is a unique disease entity or an early
manifestation of SjD is completely unknown. The overall goal is to characterize mechanisms by which mitochondrial
dsRNAs (mtdsRNA) are released into the cytoplasm and activate the cytosolic dsRNA sensor, protein kinase R (PKR),
for the proinflammatory signature found in cSjD CD14+ monocytes. Our preliminary data from scRNA-seq of cSjD
monocytes revealed the aberrant expression of mtdsRNA processors, such as SUV3 (ATP-dependent RNA helicase,
suppressor of variegation 3, SUPV3L1 gene) and PNPase (polyribonucleotide nucleotidyltransferase, PNPT1 gene),
PKR, type I IFN signature (I-IFN), STAT1, and CD52. A higher percentage of cSjD monocytes were positive for
particulate cytoplasmic dsRNA with downregulated SUV3 and upregulated PNPase when compared to healthy control
monocytes. SUV3-deficient cell lines concurred consistently with cytoplasmic mtdsRNA accumulation, PKR activation,
and ISG induction. In addition, we found mitochondrial RNA binding proteins (mtRBPs) crucial in maintaining
mtdsRNA stability within the matrix and novel endogenous short duplex RNAs (e-sdRNA) bound to PKR, which may
sequester PKR as a monomer to prevent its activation. Furthermore, our scRNA-seq data of PBMC clearly pinpoint
CD52 downregulation detected only in cSjD monocytes compared to monocytes from other pediatric groups or adult
SjD. Therefore, we propose our novel central hypothesis that defective mtdsRNA degradation by the aberrant SUV3
and PNPase expression in the mitochondria leads to cytoplasmic mtdsRNA accumulation, which activates the
cytosolic dsRNA sensor, PKR, in cSjD monocytes. The three proposed aims included: Aim 1. Characterize PKR
sensing of mtdsRNA in cSjD monocytes. We will determine if PKR is the key cytosolic sensor for autologous
mtdsRNAs in I-IFN+CD14+cSjD Mo and if novel e-sdRNAs bound to PKR regulate its activation. Aim 2. Identify
molecules involved in impaired mtdsRNA degradation and release into the cytoplasm. We will identify the
impact of upregulated PNPase in cSjD Mo by hypothesizing that PNPase overexpression amplifies PKR activation
through the degradation of e-sdRNAs bound to PKR. Additionally, novel mtRBPs will be tested to determine if they
permit mtdsRNA to escape into the cytoplasm by altering the methylation status of mitochondrial transcripts. Aim 3.
Stratify biological and clinical features of cSjD for precision medicine. We will test if the downregulation of anti-
inflammatory, anti-adhesion CD52 in cSjD Mo is mediated by the mtdsRNA-PKR-STAT1 pathway to enhance
extravasation through endothelial cells for tissue homing. We will also stratify transcriptomic, immunological, genetic,
molecular, clinical, and laboratory features of cSjD by expanding our ongoing scRNA-seq of PBMC and paired biopsy
tissues, and RNA-seq of Mo for validation. Our novel mechanistic studies on mtdsRNA, along with NGS, will lead to
cSjD molecular barcodes and pertinent RNA therapy involving e-sdRNAs to dampen PKR activation in cSjD.
Terms: <0-11 years old><21+ years old><Address><Adhesions><Adolescent><Adolescent Youth><Adult><Adult Human><Affect><Anti-Inflammatories><Anti-Inflammatory Agents><Anti-inflammatory><Area><Asialia><Autoimmune><Autoimmune Diseases><Autologous><Award><B-Cell NHL><B-Cell Non-Hodgkin's Lymphoma><B-Cell NonHodgkins Lymphoma><Bar Codes><Binding Proteins><Biological><Biological Response Modifiers><Biomodulators><Biopsy><Blood monocyte><Body Tissues><CD14><CD14 gene><CD52><CDW52><CDW52 gene><Cell Body><Cell Line><CellLine><Cells><Child><Child Youth><Childhood><Children (0-21)><Clinical><Co-Immunoprecipitations><Collaborations><Cytoplasm><DNA Helicases><DNA Unwinding Proteins><DNA unwinding enzyme><Data><Data Set><Deposit><Deposition><Development><Diagnostic><Disease><Disorder><Double-Stranded RNA><Down-Regulation><Early Intervention><Elderly><Endothelial Cells><Enrollment><Exocrine Glands><Exploratory/Developmental Grant for Diagnostic Cancer Imaging><Extravasation><Female><Foundations><Funding><Gene Amplification><Gene Expression><Gene Targeting><Genes><Genetic><Goals><Health><Heterogeneity><Homing><Hospitals><Hyposalivation><IFN><Immune><Immune Cell Activation><Immune Mediators><Immune Mediators/Modulators><Immune Regulators><Immunes><Immunochemical Immunologic><Immunologic><Immunological><Immunologically><Immunologics><Impairment><Incidence><Inflammation><Inflammatory><Interferons><Investigation><Knowledge><Laboratories><Leakage><Ligand Binding Protein><Ligand Binding Protein Gene><Lip><Lip structure><Marrow monocyte><Mediating><Medical><Methylation><Mitochondria><Mitochondria RNA><Mitochondrial Proteins><Mitochondrial RNA><Molecular><Molecular Analysis><Molecular Disease><Mouth Dryness><NIAMS><NIH><National Institute of Arthritis, and Musculoskeletal, and Skin Diseases><National Institutes of Health><Natural History><Non-Polyadenylated RNA><Nucleic Acids><Organ><Orphan Disease><Outcome><PBMC><Particulate><Pathogenesis><Pathway interactions><Patients><Peripheral Blood Mononuclear Cell><Polynucleotide Phosphorylase><Polyribonucleotide Nucleotidyltransferase><Prevalence><Prognostic Marker><Protein Binding><R21 Award><RNA><RNA Binding><RNA Degradation><RNA Gene Products><RNA Helicase><RNA Seq><RNA based therapeutics><RNA based therapy><RNA bound><RNA sequencing><RNA therapy><RNA-Binding Proteins><RNAseq><Rare Diseases><Rare Disorder><Research><Ribonucleic Acid><STAT1><STAT1 gene><STAT91><Sicca Syndrome><Sjogren's Syndrome><Sjogrens><Sjögren Syndrome><Spillage><Staining method><Stains><Strains Cell Lines><Stratification><Testing><Tissues><Transcript><United States National Institutes of Health><Up-Regulation><Upregulation><Validation><Xerostomia><adulthood><advanced age><aptyalism><autoimmune condition><autoimmune disorder><autoimmunity disease><barcode><biologic><biomarker discovery><bound protein><cohort><cultured cell line><developmental><diagnostic biomarker><diagnostic criteria><diagnostic marker><disease diagnostic><dry eye><dry mouth><dsRNA><enroll><eye dryness><gene signatures><genetic signature><geriatric><helicase><immune activation><immunomodulatory biologics><innate immune mechanisms><juvenile><juvenile human><kids><mitochondrial><monocyte><monomer><mtRNA><multidisciplinary><multiomics><multiple omics><natural gene amplification><novel><orphan disorder><overexpress><overexpression><panomics><pathway><pediatric><personalization of treatment><personalized medicine><personalized therapy><personalized treatment><precision medicine><precision-based medicine><prevent><preventing><prognostic biomarker><protein kinase R><scRNA-seq><senior citizen><sensor><simulation><single cell RNA-seq><single cell RNAseq><single cell expression profiling><single cell transcriptomic profiling><single-cell RNA sequencing><therapeutic RNA><therapeutic target><transcriptome sequencing><transcriptomic sequencing><transcriptomics><validations><xerodermosteosis><youngster>