Mitochondrial Dysfunction and Fatigue in Sjögren's Disease.

Area of Science:

• Immunology
• Cellular Biology
• Bioenergetics

Background:

• Sjögren's disease (SjD) is characterized by inflammation, dryness, and profound fatigue.
• Mitophagy, the process of clearing damaged mitochondria, may be dysregulated in autoimmune disorders.
• Persistently dysfunctional mitochondria can elevate reactive oxygen species, potentially contributing to disease pathology.

Purpose of the Study:

• To investigate the hypothesis that mitophagic processes are dysregulated in SjD.
• To determine if dysfunctional mitochondria contribute to fatigue in SjD patients.
• To assess the pathogenic extent and implications of dysregulated mitophagy in SjD.

Main Methods:

• Pan T cells were isolated from SjD patients and healthy controls.
• Mitochondrial oxygen consumption rate (OCR) and glycolysis were measured using Seahorse.
• Mitophagy transcriptional signatures were analyzed using whole-blood microarray data.

Main Results:

• SjD patients exhibited significantly lower basal OCR, ATP-linked respiration, maximal respiration, and reserve capacity compared to healthy subjects.
• Lymphocytic mitochondria showed structural alterations in SjD.
• Fatigue scores correlated with altered OCR in SjD patients.

Conclusions:

• Mitochondrial dysfunction is a significant issue in SjD, directly associated with patient fatigue.
• Dysregulated mitophagy and impaired cellular respiration are implicated in SjD pathogenesis.
• Further investigation into mitochondrial dysfunction in SjD is warranted.