Female mice with systemic lupus erythematosus produce antibodies to mitochondrial antigens and have impaired renal mitochondrial function
Abstract Body: Patients with autoimmune disorders like systemic lupus erythematosus (SLE) are at significant risk for renal and cardiovascular mortality. The pathology of SLE is driven by a loss of immune tolerance with the subsequent production of autoantibodies (IgG), and our laboratory previously demonstrated a mechanistic role for autoantibodies in autoimmune mediated hypertension. While anti-double stranded DNA (dsDNA) antibodies are pathognomonic for SLE, a breadth of autoantibodies may contribute to disease pathology. The goal of this study is to identify autoantibodies that may contribute to the renal and cardiovascular consequences associated with SLE. To accomplish this goal, an antigen array was performed (University of Texas Southwestern Genomics & Microarray Core Facility) using plasma samples collected from an established experimental mouse model of SLE (30 week old female NZBWF1, n=8) and healthy controls (30 week old female NZWLacJ, n=7). As anticipated, autoantibodies raised to nuclear antigens were prominently represented in the array and were significantly increased relative to control mice. This includes antibodies to dsDNA, ssRNA, chromatin, and histones (total) (p<0.02). In addition, SLE mice produce antibodies to mitochondrial antigens including cardiolipin and cytochrome C (p<0.02 vs control mice), critical components of the inner mitochondrial membrane and respiratory chain, respectively. In a separate study, renal mitochondrial function was tested using high resolution respirometry (Oroboros Instruments) in whole kidney homogenates from 30 week old female SLE (n=6) and control mice (n=5). Results show that coupled respiration, an estimation of oxidative phosphorylation, is significantly impaired at Complex I in kidneys from SLE mice compared to healthy controls (62±9 vs. 90±7 pmol/s/mg tissue, p<0.05). Uncoupled respiration, an estimation of maximal electron transport, is also reduced in the kidneys of female SLE mice compared to controls (157±23 vs. 212±14 pmol/s/mg tissue, p=0.07). These data provide insight for new mechanistic pathways to pursue in understanding the underlying mechanisms promoting cardiovascular risk factors like hypertension during SLE.
Frambes, Noelle
( UofSC School of Medicine
, Columbia
, South Carolina
, United States
)
Hollis, Fiona
( UofSC School of Medicine
, Lexington
, South Carolina
, United States
)
Taylor, Erin
( UNIVERSITY OF MS MEDICAL CENTER
, Jackson
, Mississippi
, United States
)
Srivastava, Baruk
( UofSC School of Medicine
, Columbia
, South Carolina
, United States
)
Sullivan, Kelly
( UofSC School of Medicine
, Columbia
, South Carolina
, United States
)
Ryan, Michael
( UofSC School of Medicine
, Columbia
, South Carolina
, United States
)
Author Disclosures:
Noelle Frambes:DO NOT have relevant financial relationships
| Fiona Hollis:DO NOT have relevant financial relationships
| Erin Taylor:DO NOT have relevant financial relationships
| Baruk Srivastava:No Answer
| Kelly Sullivan:No Answer
| Michael Ryan:DO NOT have relevant financial relationships