Galectin-1 Restores Immune Tolerance to Liver Transplantation Through Activation of Hepatic Stellate Cells.

BACKGROUND/AIMS: Immune tolerance is considered the only way to manage liver transplantation (LT). The current study hypothesized that galectin-1 via the activation of hepatic stellate cells (HSCs) is capable of inducing immune tolerance in LT. METHODS: Lentiviral-mediated gene knockdown and overexpression of galectin-1 were conducted in HSC-T6 cells. Reverse transcription quantitative polymerase chain reaction and western blot analysis were used to determine galectin-1 expression. LT was performed in 20 C57BL/J6 mice and 20 C3H mice. T-cells were assigned into control, Galectin-1 shRNA, Galectin-1 OE, Galectin-1 OE SB431542, Galectin-1 OE Sulforaphane, Galectin-1 OE Y27632, and Galectin-1 OE UO126 groups. CFSE, flow cytometry, and ELISA were respectively employed to detect T-cell proliferation, CD4+/ CD8+ ratio and IL-2, IL-10 and TGF-ß levels. After establishing mouse models of immune tolerance and acute rejection, immunohistochemistry, TUNEL, and immunofluorescence assay were performed to determine CD3+ expression, apoptosis, α-SMA, and desmin. Mouse models of CCl4-induced liver fibrosis were established, followed by assigning the control1 and CCl4 groups. ELISA was used to determine ALT, AST, TBIL and Hyp levels. A total of 3 C57BL/J6 mice (donor) and 6 C3H mice (recipient) were grouped into the control2 and UO126 groups, followed by ELISA detection for IL-2, IL-10 and TGF-ß. RESULTS: In T-cells, galectin-1 shRNA increased cell proliferation and IL-2 levels with reduced IL-10 and TGF-ß levels, while the Galectin-1 OE and Galectin-1 OE UO126 groups revealed the opposite results. Galectin-1 overexpression elevated the ratio of the CD4+ to CD8+ T-cells. The acute rejection group exhibited enhanced desmin expression and reduced α-SMA expression. Compared with the immune tolerance group, the acute rejection group displayed higher galectin-1 expression, a positive expression rate of CD3+ T-cells, and an increased apoptosis rate. Compared with the control1 group, the CCl4 group exhibited higher galectin-1 expression, ALT, AST, TBIL, and Hyp levels, α-SMA expression and CD4+/CD8+ T-cell ratio, in addition to decreased expression of desmin. Compared with the control2 group, UO126 increased galectin-1 expressions, IL-10 and TGF-ß levels and reduced IL-2 levels with inactivated HSCs. CONCLUSIONS: The findings of the current study indicated that the overexpression of galectin-1 promoted the activation of HSCs, which reduced the inflammatory response by exerting immunosuppressive effects and accordingly contributed to immune tolerance in LT.

Self-assembly of a ruthenium-based cGAS-STING photoactivator for carrier-free cancer immunotherapy.

The cGAS (cyclic GMP-AMP synthase)-STING (stimulator of interferon genes) pathway promotes antitumor immune responses by sensing cytosolic DNA fragments leaked from nucleus and mitochondria. Herein, we designed a highly charged ruthenium photosensitizer (Ru1) with a ß-carboline alkaloid derivative as the ligand for photo-activating of the cGAS-STING pathway. Due to the formation of multiple non-covalent intermolecular interactions, Ru1 can self-assemble into carrier-free nanoparticles (NPs). By incorporating the triphenylphosphine substituents, Ru1 can target and photo-damage mitochondrial DNA (mtDNA) to cause the cytoplasmic DNA leakage to activate the cGAS-STING pathway. Finally, Ru1 NPs show potent antitumor effects and elicit intense immune responses in vivo. In conclusion, we report the first self-assembling mtDNA-targeted photosensitizer, which can effectively activate the cGAS-STING pathway, thus providing innovations for the design of new photo-immunotherapeutic agents.

Rising Interest in the Development of Metal Complexes in Cancer Immunotherapy.

Metal complexes have shown great potential in cancer immunotherapy. This review briefly introduces the basic concepts and strategies of cancer immunotherapy and summarizes the recent discoveries on the immune effects of traditional platinum-based anticancer compounds. In addition, we also outline the latest research progresses on metal complexes for cancer immunotherapy focusing on platinum, ruthenium, iridium, rhenium and copper complexes. Finally, the research perspectives and unsolved problems on the applications of metallo-anticancer agents in cancer immunotherapy are purposed.

[Application of rhodamine-based fluorescence chemosensor in heavy metal ions and transition metal ions detection].

As one of the fluorescent molecules with high quantum yield, rhodamine was often chosen as the mother molecule in the synthesis of metal ion fluorescence chemosensor. The present paper reviews the applications of rhodamine fluorescence chemosensors in the analysis of heavy metal ions and transition metal ions including the response mechanism, the kinds of targeted ion, scope of application and corresponding detection limit. In addition, the existing challenges and future development directions in the research of rhodamine-based metal ion fluorescence chemosensor are discussed.

Galectin-1 gene silencing inhibits the activation and proliferation but induces the apoptosis of hepatic stellate cells from mice with liver fibrosis.

Liver fibrosis is a serious threat to human health, and there is currently no effective clinical drug for treatment of the disease. Although Galectin­1 is effective, its role in liver function, inflammation, matrix metalloproteinases and the activation of hepatic stellate cells (HSCs) remains to be elucidated. The aim of the present study was to elucidate the effect of Galectin­1 on the activation, proliferation and apoptosis of HSCs in a mouse model of liver fibrosis. Following successful model establishment and tissue collection, mouse HSCs (mHSCs) were identified and an mHSC line was constructed. Subsequently, to determine the role of Galectin­1 in liver fibrosis, the expression levels of transforming growth factor (TGF)­ß1, connective tissue growth factor (CTGF) and α­smooth muscle actin (α­SMA) pre­ and post­transfection were evaluated by reverse transcription­quantitative polymerase chain reaction and western blot analyses. In addition, the effects of Galectin­1 on the biological behavior and mitochondrial function of mHSCs were determined using a 3­(4,5­dimethylthiazol­2­yl)­2,5­diphenyltetrazolium bromide assay, flow cytometry and a scratch test. It was first observed that the expression levels of Galectin­1, TGF­ß1, CTGF and α­SMA were downregulated by silencing the gene expression of Galectin­1. Additionally, silencing the gene expression of Galectin­1 inhibited cell cycle progression, proliferation and migration but induced the apoptosis of mHSCs from mice with liver fibrosis. Furthermore, the in vivo experimental results suggested that silencing the gene expression of Galectin­1 improved liver fibrosis. Collectively, it was concluded that silencing the gene expression of Galectin­1 ameliorates liver fibrosis and that functionally suppressing Galectin­1 may be a future therapeutic strategy for liver fibrosis.