Intermittent fasting confers protections to various diseases including autoimmune disorders, but the specific effects of intermittent fasting on Sjögren's syndrome (SS) remains inconclusive. The present study was undertaken to determine the specific impact of alternate-day fasting (ADF) on newly established SS-like sialadenitis using non-obese diabetic (NOD) mice. Female NOD mice were deprived of food every other day from 10 to 13 weeks of age, the early stage of established SS, and then analyzed for the disease characteristics. Mice in the ADF group had higher salivary flow rate and attenuated submandibular gland (SMG) inflammation, compared to the control mice fed with standard chow ad libitum. The improvements were accompanied with a decrease in the total leukocytes, T and B lymphocytes and activated CD4 and CD8 T cells, and a down-regulation of pro-inflammatory cytokines IFN-γ and IL-17, chemokine receptor CXCR3 and its ligands CXCL9 and CXCL11 in the SMGs. ADF also led to elevated mRNA levels of water channel protein aquaporin 5 and tight junction protein claudin-1, two factors crucial for normal salivary secretion in the SMGs. In addition, ADF reduced the proportion of IFN-γ- and IL-17- expressing CD4 T cells and diminished mRNA levels of IFN-γ, TNF-α, and IL-17 in the total submandibular draining lymph node cells. Taken together, ADF is effective in ameliorating newly established SS-associated salivary gland exocrinopathy in NOD mice.
Keywords: Sjögren’s syndrome; alternate-day fasting; leukocyte infiltration; salivary secretion.