FTY720 mediates activation suppression and G0/G1 cell cycle arrest in a concanavalin A-induced mouse lymphocyte pan-activation model

Early-life fingolimod treatment improves intestinal homeostasis and pancreatic immune tolerance in non-obese diabetic mice

Fingolimod has beneficial effects on multiple diseases, including type 1 diabetes (T1D) and numerous preclinical models of colitis. Intestinal dysbiosis and intestinal immune dysfunction contribute to disease pathogenesis of T1D. Thus, the beneficial effect of fingolimod on T1D may occur via the maintenance of intestinal homeostasis to some extent. Herein, we investigated the role of fingolimod in intestinal dysfunction in non-obese diabetic (NOD) mice and possible mechanisms. NOD mice were treated with fingolimod (1 mg · kg-1 per day, i.g.) from weaning (3-week-old) to 31 weeks of age. We found that fingolimod administration significantly enhanced the gut barrier (evidenced by enhanced expression of tight junction proteins and reduced intestinal permeability), attenuated intestinal microbial dysbiosis (evidenced by the reduction of enteric pathogenic Proteobacteria clusters), as well as intestinal immune dysfunction (evidenced by inhibition of CD4+ cells activation, reduction of T helper type 1 cells and macrophages, and the expansion of regulatory T cells). We further revealed that fingolimod administration suppressed the activation of CD4+ cells and the differentiation of T helper type 1 cells, promoted the expansion of regulatory T cells in the pancreas, which might contribute to the maintenance of pancreatic immune tolerance and the reduction of T1D incidence. The protection might be due to fingolimod inhibiting the toll-like receptor 2/4/nuclear factor-κB/NOD-like receptor protein 3 inflammasome pathway in the colon. Collectively, early-life fingolimod treatment attenuates intestinal microbial dysbiosis and intestinal immune dysfunction in the T1D setting, which might contribute to its anti-diabetic effect.

FTY720, a sphingosine-1 phosphate receptor modulator, improves liver fibrosis in a mouse model by impairing the motility of bone marrow-derived mesenchymal stem cells

FTY720 is a novel immunosuppressant that modulates sphingosine 1-phosphate (S1P) receptors for the treatment of several diseases. Several hallmarks of liver fibrosis are influenced by S1P, and the interference of S1P signaling by treatment with FTY720 results in beneficial effects in various animal models of fibrosis. However, whether these treatment strategies suppress liver fibrosis progression is incompletely understood. Here, we investigated the effects and mechanisms by which FTY720 improves liver fibrosis in the carbon tetrachloride (CCl4)-induced mouse model. FTY720 treatment significantly attenuated the expression of fibrotic markers in the injured liver of both wild-type and SCID-beige mice. The migration of bone marrow-derived mesenchymal stem cells (BMSCs) to circulation, and subsequently the injured liver, was suppressed by FTY720. Furthermore, in vitro, phosphorylated-FTY720 blocked the migration of BMSCs mediated by S1P. Thus, FTY720 is an effective therapy for liver fibrosis via the suppression of BMSC migration in the CCl4-induced mouse model.

Emodin inhibits splenocyte proliferation and inflammation by modulating cytokine responses in a mouse model system

Emodin, an anthraquinone derivative, was investigated for potential anti-inflammatory and anti-proliferative effects in vitro. The potential to induce these outcomes was assessed using concanavalin A (ConA)-stimulated mouse splenocytes. Dose-response studies showed that emodin at 100 µM was not cytotoxic to naive cells, and that the same dose caused proliferation to be significantly reduced in ConA-stimulated cells. In addition, emodin significantly reduced ConA-induced nitric oxide (NO) production and the formation/release of TH1 (IL-2, IFNγ, TNFα) and TH17 (IL-6 and IL-17) cell cytokines, but induced those of TH2 (IL-4) and Treg (IL-10) cells. From the results, it is concluded that earlier-reported immunomodulatory effects imparted by emodin may have been attributable, in part, to anti-proliferative effects on lymphocytes, as well as a shift within the TH1/TH2 and TH17/Treg balance (towards TH2 and Treg). These findings, while providing evidence of mechanisms of emodin immunomodulation, are also potentially important for sparking studies that ultimately may result in the potential use of this agent in preventive and/or corrective strategies against autoimmune and other inflammatory diseases.