A study in the journal Autoimmunity reveals that a key compound in green tea, epigallocatechin-3-gallate (EGCG), can normalize cellular stress markers in the glands of mice predisposed to an autoimmune disease similar to Sjögren's syndrome, long before clinical symptoms appear. This discovery could pave the way for new strategies for the early diagnosis and intervention of autoimmune disorders.
Sjögren's syndrome is an autoimmune condition that primarily damages salivary and lacrimal glands, leading to chronic dry mouth and eyes. Its triggers are poorly understood, but oxidative stress and resulting DNA damage in glandular cells are believed to be early events in its development.
This research focused on identifying these early molecular changes and whether they could be prevented.
Key Findings from the Study:
Using a mouse model for primary Sjögren's syndrome (NOD.B10.Sn-H2 mice), researchers tracked key cellular proteins from a young age, before the onset of overt disease.
Early DNA Damage Signal: In untreated mice, levels of Proliferating Cell Nuclear Antigen (PCNA), a key protein involved in DNA repair, were significantly elevated in the submandibular (salivary) glands and pancreas as early as 8 weeks of age. This occurred well before the infiltration of inflammatory cells, which is a classic sign of the disease.
Reduced Antioxidant Defense: Following the increase in PCNA, the researchers observed a significant decline in the levels of peroxiredoxin 6 (PRDX6), a critical antioxidant enzyme that protects cells from damage.
EGCG Prevents Damage Markers: In stark contrast, mice that consumed EGCG in their drinking water from a young age did not show these abnormalities. Their levels of both PCNA and PRDX6 remained normal and comparable to those of healthy control mice throughout the study period.
Systemic Effect: These protective effects were observed not only in the salivary glands but also in the pancreas, suggesting that EGCG's benefits may extend to multiple exocrine glands susceptible to autoimmune-related stress.
Conclusion:
The study suggests that elevated PCNA and the subsequent decline of PRDX6 are very early biomarkers of cellular stress that precedes the autoimmune attack in Sjögren's syndrome. The fact that EGCG consumption can prevent these changes highlights its potential as a preventative agent. By targeting the disease process at its earliest stages, these findings offer a new direction for developing interventions that could potentially delay or even prevent the onset of Sjögren's syndrome and other related autoimmune disorders.
Source & Link to Original Article:
For credibility and academic integrity, the original research paper is cited below. You can access the full article via the following link.
Citation: Ohno, S., Yu, H., Dickinson, D., Chu, T. C., Ogbureke, K., DeRossi, S., Yamamoto, T., & Hsu, S. (2012). Epigallocatechin-3-gallate modulates antioxidant and DNA repair-related proteins in exocrine glands of a primary Sjögren's syndrome mouse model prior to disease onset. Autoimmunity, 45(7), 540–546.
Link: https://www.tandfonline.com/doi/full/10.3109/08916934.2012.710860
