Original Research ArticleAltered mitochondrial proteome and functional dynamics in patients with rheumatoid arthritis
Introduction
Immune system defends our body against invaders and while doing so it needs to expend energy to fight infections (Ganeshan and Chawla, 2014). An immune dysfunction can lead to autoimmunity wherein the self-damaging immune effector responses are manifested (Janeway et al., 2001). Mitochondria are specialized organelles extensively identified for their bioenergetic capacities as well as numerous cellular functions including calcium signalling, steroid and heme synthesis, cellular metabolism and apoptosis (Chinnery and Hudson, 2013). Subtle changes in the mitochondrial capacities accounting for an imbalance between energy production and demand as well as transfer of different signalling components can lead to amplified disturbances in cellular structures and functions thereby playing important roles in various pathological conditions. Thus understanding the involvement of mitochondria in pathogenesis of different diseases becomes crucial.
Any alteration in mitochondrial oxidative phosphorylation (OXPHOS), mitochondrial membrane potential (ΔΨm), respiration, reactive oxygen species (ROS) production, proton leak, classified as mitochondrial dysfunction, can critically regulate numerous cellular signalling mechanisms (Brand and Nicholls, 2011) and has been reported in pathogenesis of various metabolic and autoimmune diseases including diabetes (Pieczenik and Neustadt, 2007), Huntington’s disease (Pieczenik and Neustadt, 2007), Systemic lupus erythematosus (SLE) (Perl et al., 2004), Sjogren’s syndrome (Pagano et al., 2013) and different cancers (Hsu et al., 2016).
Rheumatoid arthritis (RA) is a systemic and chronic inflammatory disease with autoimmune responses and inflammation leading to bone and joint destruction (Chimenti et al., 2015). Both innate and adaptive immune systems play discrete roles in contributing towards RA pathology (Chimenti et al., 2015). The bystander activation of immune cells at the joints further amplifies the disease symptoms (Chimenti et al., 2015). Mitochondria play an important role in metabolic reprogramming of immune cells to meet the altered bioenergetic demands. Recent reports suggest important links between mitochondrial respiratory and metabolic capacities with development of T cell effector and memory functions (Buck et al., 2016). Osteoclast survival and bone resorption capacities have also been directly associated with mitochondrial capacities of ATP production (Miyazaki et al., 2012). We also reported changes in cell free DNA, including mitochondrial DNA (mtDNA), in RA patients that may be involved in pathogenesis of the disease (Khanna et al., 2018). As RA is characterized by the integral changes in peripheral and migrant site specific immune cells, osteoclasts and fibroblasts, it thus becomes essential to monitor and analyze the metabolic machinery of these cells to build better therapeutic strategies directly targeting the mitochondria to improve patient’s health. We thus analyzed and quantified the differential mitochondrial proteome in RA patients using isobaric tags for relative and absolute quantitation (iTRAQ) labelling coupled with liquid chromatography-tandem mass spectrometry (LC–MS/MS) followed by mRNA transcript analysis to assess changes that might be responsible for the observed differences in the proteome. Any anomalies in mitochondrial functions were assessed in parallel in RA PBMCs.
Section snippets
Patient inclusion
Seventy-six RA patients satisfying the 2010 ACR/EULAR classification criteria for RA diagnosis (McGeough and Bjourson, 2012), visiting rheumatology outpatient department of Pradyumna Bal Memorial Hospital, Bhubaneswar, Odisha, India and eighty seven healthy controls (HC) who donated blood at blood bank of Pradyumna Bal Memorial Hospital, Bhubaneswar were enrolled in this study. The study was approved by Institute and Hospital Research Ethics committee and all the procedures were performed in
Differential mitochondrial proteome in RA PBMCs
Using iTRAQ-LC–MS/MS followed by bioinformatics analyses, a total of 198 mitochondrial proteins were identified in each technical triplicate of both the pools of RA and HC mitochondrial protein samples (Table S4). Upon setting a fold change threshold values of 0.8 for downregulation and 1.2 for upregulation of proteins and a significance level with p-value ≤ 0.05 based on the previously published references (Li et al., 2019, Sun et al., 2017, Zhou et al., 2016) for both the biological pool
Discussion
During OXPHOS, electrons transport and proton pumping results in generation of ΔΨm which is required for ATP production (Li et al., 2006). Inefficient H+ pumping reduces ΔΨm causing lower ATP production and increased heat per calorie consumed (Li, 2012). Deficiency of OXPHOS leads to attenuated mitochondrial function (Li et al., 2015) and has been reported in different diseases (Hsu et al., 2016, Kim et al., 2017). The differential proteome analysis of our case control cohort depicts a
Conclusion
Differential expressions of the above discussed proteins indicate presence of dysfunctional mitochondria in immune cells of RA patients where complex I, II, IV and OXPHOS are compromised, membrane potential, ATP generation and mitochondrial superoxide levels are diminished, fatty acid and ketone body metabolism are compromised, phagosome maturation is upregulated, proteins involved in mitochondrial transcription and translation have altered expressions, mitophagy related proteins are
Acknowledgements
The study was supported by Department of Science and Technology (DST), India (ECR/2015/000300). Shweta Khanna is thankful to Indian Council of Medical Research for Senior Research Fellowship (Ref. No. 3/1/2/(4)/CD/18NCD-II).
References (50)
- et al.
Mitochondrial dynamics controls T cell fate through metabolic programming
Cell
(2016) - et al.
Peroxiredoxin III, a mitochondrion-specific peroxidase, regulates apoptotic signaling by mitochondria
J. Biol. Chem.
(2004) - et al.
Biallelic PPA2 mutations cause sudden unexpected cardiac arrest in infancy
Am. J. Hum. Genet.
(2016) - et al.
Mitochondrial sirtuins: regulators of protein acylation and metabolism
Trends Endocrinol. Metab.
(2012) - et al.
Short-chain acyl-coenzyme A dehydrogenase deficiency
Mol. Genet. Metab.
(2008) - et al.
MiR-31/SDHA axis regulates reprogramming efficiency through mitochondrial metabolism
Stem Cell Rep.
(2016) - et al.
The NDUFB6 subunit of the mitochondrial respiratory chain complex I is required for electron transfer activity: a proof of principle study on stable and controlled RNA interference in human cell lines
Biochem. Biophys. Res. Commun.
(2011) - et al.
Mitochondrial ribosomal protein L12 is required for POLRMT stability and exists as two forms generated by alternative proteolysis during import
J. Biol. Chem.
(2016) - et al.
Identification of NIPSNAP1 as a nocistatin-interacting protein involving pain transmission
J. Biol. Chem.
(2012) - et al.
Roles of peroxiredoxins in cancer, neurodegenerative diseases and inflammatory diseases
Pharmacol. Ther.
(2016)
Patterns, receptors, and signals: regulation of phagosome maturation
Trends Immunol.
The roles of PINK1, parkin, and mitochondrial fidelity in Parkinson’s disease
Neuron
Mitochondrial dysfunction and molecular pathways of disease
Exp. Mol. Pathol.
Mitochondrial protein translocases for survival and wellbeing
FEBS Lett.
Serum quantitative proteomic analysis of patients with keshan disease based on iTRAQ labeling technique: a first term study
J. Trace Elem. Med Biol.
Deactivating fatty acids: acyl-CoA thioesterase-mediated control of lipid metabolism
Trends Endocrinol. Metab.
Activation of peroxisome proliferator-activated receptor pathway stimulates the mitochondrial respiratory chain and can correct deficiencies in patients’ cells lacking its components
J. Clin. Endocrinol. Metab.
Assessing mitochondrial dysfunction in cells
Biochem. J.
Germline mutations in the mitochondrial 2-oxoglutarate/malate carrier SLC25A11 gene confer a predisposition to metastatic paragangliomas
Cancer Res.
The interplay between inflammation and metabolism in rheumatoid arthritis
Cell Death Dis.
Mitochondrial genetics
Br. Med. Bull.
Tom5 functionally links mitochondrial preprotein receptors to the general import pore
Nature
Mitochondrial complex I deficiency: from organelle dysfunction to clinical disease
Brain
Metabolic regulation of immune responses
Annu. Rev. Immunol.
Free radicals and redox signalling in T-cells during chronic inflammation and ageing
Biochem. Soc. Trans.
Cited by (13)
The enhanced mitochondrial dysfunction by cantleyoside confines inflammatory response and promotes apoptosis of human HFLS-RA cell line via AMPK/Sirt 1/NF-κB pathway activation
2022, Biomedicine and PharmacotherapyCitation Excerpt :Vice versa, excessive inflammatory factors could lead to uncontrolled proliferation of FLSs in RA [27,28]. The surged cytoplasmic Ca2+ and ROS could disrupt mitochondrial functional integrity and the opening of MPTP, leading to mitochondrial osmotic swelling, dissipation of MMP and mitochondrial apoptosis [29,30]. Consequently, the inhibited mitochondrial oxidative phosphorylation and ATP synthesis further exacerbated RA by forming a cycle of ‘impaired ATP synthesis-Ca2+ overload-impaired ATP synthesis’ [31,32].
Quercetin-mediated SIRT1 activation attenuates collagen-induced mice arthritis
2021, Journal of EthnopharmacologyCitation Excerpt :Mitochondria are considered to be the intracellular source of ROS in animal cells, and mitochondrial dysfunction can lead to an imbalance in the antioxidant system and oxidative stress (Munro and Treberg, 2017). Mitochondrial dysfunction and mitochondrial biogenesis are responsible for the invasion of FLSs and the continued progression of RA (Al-Azab et al., 2020; Khanna et al., 2020). Mitochondrial biogenesis is closely regulated by the SIRT1/PGC-1α/NRF1/TFAM pathway.
Increased Extracellular ATP in Plasma of Rheumatoid Arthritis Patients Activates CD8<sup>+</sup>T Cells
2021, Archives of Medical ResearchCitation Excerpt :On the contrary, cellular ATP concentration of CD8+T cells was found significantly (p <0.001) increased in RA patients in comparison to the CD8+T cells of healthy controls (751.8 ± 44.36% in RA vs. 359.3 ± 60.6% in HC, Figure 4B). The decreased intracellular ATP concentration in PBMCs of RA patients has been recently published by us (40), we thus continued our focus on the increased ATP concentration of this subset of PBMCs, the CD8+T cells. As mitochondria are a key organelle for ATP production, we aimed to determine mitochondrial dynamics in CD8+T cells of RA patients including mitochondrial mass, mitochondrial membrane potential, super oxide level and transcript analysis of genes belonging to the electron transport chain (ETC) for CD8+T cells of RA patients and healthy controls.
Role of reactive oxygen species and mitochondrial damage in rheumatoid arthritis and targeted drugs
2023, Frontiers in ImmunologyThe Involvement of Glucose and Lipid Metabolism Alteration in Rheumatoid Arthritis and Its Clinical Implication
2023, Journal of Inflammation Research
- 1
Authors have equally contributed to this work.