IL-33 and its receptor ST2 play crucial roles in tissue repair and homeostasis. However, their involvement in optic neuropathy due to trauma and glaucoma remains unclear. Here, we report that IL-33 and ST2 were highly expressed in the mouse optic nerve and retina. Deletion of IL-33 or ST2 exacerbated retinal ganglion cell (RGC) loss, retinal thinning, and nerve fiber degeneration following optic nerve (ON) injury. This heightened retinal neurodegeneration correlated with increased neurotoxic astrocytes in Il33^-/- mice. In vitro, rIL-33 mitigated the neurotoxic astrocyte phenotype and reduced the expression of pro-inflammatory factors, thereby alleviating the RGC death induced by neurotoxic astrocyte-conditioned medium in retinal explants. Exogenous IL-33 treatment improved RGC survival in Il33^-/- and WT mice after ON injury, but not in ST2^-/- mice. Our findings highlight the role of the IL-33/ST2 axis in modulating reactive astrocyte function and providing neuroprotection for RGCs following ON injury.
Animals ; Interleukin-33/genetics* ; Interleukin-1 Receptor-Like 1 Protein/genetics* ; Optic Nerve Injuries/pathology* ; Retinal Ganglion Cells/pathology* ; Astrocytes/pathology* ; Mice ; Mice, Knockout ; Mice, Inbred C57BL ; Neuroprotection/physiology*

AIM:To explore the protective effect of Xiaoxuming decoction(XXMD)on synaptic plasticity in the context of cerebral ischemia-reperfusion injury following ischemic stroke.METHODS:An oxygen-glucose depriva-tion/reoxygenation(OGD/R)model was employed in vitro using mouse hippocampal neurons(HT22 cells)to simulate ischemia-reperfusion injury.Cell viability was assessed using a CCK-8 assay to determine the optimal XXMD concentra-tion.The HT22 cells were divided into two groups:control and model(OGD/R).Cellular morphological changes were ob-served using an inverted microscope.The levels of IL-1β,IL-6 and TNF-α in the supernatant were quantified by ELISA.Ultrastructural changes were examined by transmission electron microscopy.Immunofluorescence staining was used to de-tect neuron markers NeuN and synaptic proteins NF200 and MAP2.The protein levels of NF200 and MAP2 were analyzed by Western blot.RESULTS:The highest cell survival rate occurred at an XXMD concentration of 100 mg/L(P<0.05).Compared with control group,the cells in model group exhibited round shape and shrinkage,mitochondrial swelling or vacuolization,and a marked decrease in survival rate.There were significant increases in IL-1β,IL-6 and TNF-α levels(P<0.05).Immunofluorescence intensity and protein levels of NeuN,NF200 and MAP2 were notably reduced(P<0.05).Treatment with XXMD improved cell morphology,ultrastructure and survival rate(P<0.05),and decreased in-flammatory factor levels(P<0.05).Compared with model group,the cells in OGD/R+XXMD group showed significantly increased immunofluorescence intensity and protein levels of NeuN,NF200 and MAP2(P<0.05).CONCLUSION:Xiaoxuming decoction may mitigate OGD/R-induced injury,potentially by inhibiting inflammatory responses and enhanc-ing synaptic plasticity.

HMGB1's role in tumors is complex and diverse,and it exerts its biological function by combining with different receptors.One of the receptors is called RAGE,which is localized to the cell membrane and binds to HMGB1 released outside the cell.The HMGB1/RAGE axis promotes tumor development,moreover,tumor development and its drug resistance are closely related to inflammation.This article mainly reviews the molecular mechanism of HMGB1/RAGE axis in pro-inflammatory and protumor effects in pancreatic,colorectal and liver cancers.We also summarize the research progress of papaverine and its derivatives for the treatment of HMGB1/RAGE axis in tumor inflammation,with aims of providing new ideas for exploring the molecular mechanism of action in tumor inflammation,and providing a new theoretical basis for the research of HMGB1/RAGE axis therapeutics.

High mobility group box 1 (HMGB1) has been reported to play an important role in experimental autoimmune encephalomyelitis (EAE). Astrocytes are important components of neurovascular units and tightly appose the endothelial cells of microvessels by their perivascular endfeet and directly regulate the functions of the blood-brain barrier. Astrocytes express more HMGB1 during EAE while the exact roles of astrocytic HMGB1 in EAE have not been well elucidated. Here, using conditional-knockout mice, we found that astrocytic HMGB1 depletion decreased morbidity, delayed the onset time, and reduced the disease score and demyelination of EAE. Meanwhile, there were fewer immune cells, especially pathogenic T cells infiltration in the central nervous system of astrocytic HMGB1 conditional-knockout EAE mice, accompanied by up-regulated expression of the tight-junction protein Claudin5 and down-regulated expression of the cell adhesion molecules ICAM1 and VCAM1 in vivo. In vitro, HMGB1 released from astrocytes decreased Claudin5 while increased ICAM1 and VCAM1 expressed by brain microvascular endothelial cells (BMECs) through TLR4 or RAGE. Taken together, our results demonstrate that HMGB1 derived from astrocytes aggravates EAE by directly influencing the immune cell infiltration-associated functions of BMECs.
Mice ; Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; Astrocytes/metabolism* ; HMGB1 Protein/metabolism* ; Endothelial Cells/metabolism* ; Mice, Inbred C57BL ; Mice, Knockout ; Blood-Brain Barrier/metabolism*