C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 pathway as a therapeutic target and regulatory mechanism for spinal cord injury

Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis exhibits significant differences before and after injury.Recent studies have revealed that the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis is closely associated with secondary inflammatory responses and the recruitment of immune cells following spinal cord injury,suggesting that this axis is a novel target and regulatory control point for treatment.This review comprehensively examines the therapeutic strategies targeting the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis,along with the regenerative and repair mechanisms linking the axis to spinal cord injury.Additionally,we summarize the upstream and downstream inflammatory signaling pathways associated with spinal cord injury and the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review primarily elaborates on therapeutic strategies that target the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the latest progress of research on antagonistic drugs,along with the approaches used to exploit new therapeutic targets within the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the development of targeted drugs.Nevertheless,there are presently no clinical studies relating to spinal cord injury that are focusing on the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review aims to provide new ideas and therapeutic strategies for the future treatment of spinal cord injury.

Homoharringtonine promotes heart allograft acceptance by enhancing regulatory T cells induction in a mouse model

Background:Homoharringtonine(HHT)is an effective anti-inflammatory,anti-viral,and anti-tumor protein synthesis inhibitor that has been applied clinically.Here,we explored the therapeutic effects of HHT in a mouse heart transplant model.Methods:Healthy C57BL/6 mice were used to observe the toxicity of HHT in the liver,kidney,and hematology.A mouse heart transplantation model was constructed,and the potential mechanism of HHT prolonging allograft survival was evaluated using Kaplan-Meier analysis,immunostaining,and bulk RNA sequencing analysis.The HHT-T cell crosstalk was modeled ex vivo to further verify the molecular mechanism of HHT-induced regulatory T cells(Tregs)differentiation.Results:HHT inhibited the activation and proliferation of T cells and promoted their apoptosis ex vivo.Treatment of 0.5 mg/kg HHT for 10 days significantly prolonged the mean graft survival time of the allografts from 7 days to 48 days(P<0.001)without non-immune toxicity.The allografts had long-term survival after continuous HHT treatment for 28 days.HHT significantly reduced lymphocyte infiltration in the graft,and interferon-γ-secreting CD4^(+)and CD8^(+)T cells in the spleen(P<0.01).HHT significantly increased the number of peripheral Tregs(about 20%,P<0.001)and serum interleukin(IL)-10 levels.HHT downregulated the expression of T cell receptor(TCR)signaling pathway-related genes(CD4,H2-Eb1,TRAT1,and CD74)and upregulated the expression of IL-10 and transforming growth factor(TGF)-βpathway-related genes and Treg signature genes(CTLA4,Foxp3,CD74,and ICOS).HHT increased CD4^(+)Foxp3^(+)cells and Foxp3 expression ex vivo,and it enhanced the inhibitory function of inducible Tregs.Conclusions:HHT promotes Treg cell differentiation and enhances Treg suppressive function by attenuating the TCR signaling pathway and upregulating the expression of Treg signature genes and IL-10 levels,thereby promoting mouse heart allograft acceptance.These findings may have therapeutic implications for organ transplant recipients,particularly those with viral infections and malignancies,which require a more suitable anti-rejection medication.