Ursolic acid molecules dock MAPK1 to modulate gut microbiota diversity to reduce neuropathic pain.

To investigate the efficacy of Ursolic acid in alleviating neuropathic pain in rats with spinal nerve ligation (SNL), the SNL rat model was surgically induced. Different concentrations of Ursolic acid and manipulated target mitogen-activated protein kinase 1 (MAPK1) were administered to the SNL rats. Fecal samples were collected from each group of rats for 16S rDNA analysis to examine the impact of gut microbiota. Molecular docking experiments were conducted to assess the binding energy between Ursolic acid and MAPK1. In vivo studies were carried out to evaluate the expression of inflammatory factors and signaling pathways in spinal cord and colon tissues. Ursolic acid was found to have a beneficial effect on pain reduction in rats by increasing plantar withdrawal latency (PWL) and paw withdrawal threshold (PWT). Comparing the Ursolic acid group with the control group revealed notable differences in the distribution of Staphylococcus, Allobaculum, Clostridium, Blautia, Bifidobacterium, and Prevotella species. Network pharmacology analysis identified MAPK1 and intercellular adhesion molecule-1 (ICAM1) as common targets for Ursolic acid, SNL, and neuropathic pain. Binding sites between Ursolic acid and these targets were identified. Additionally, immunofluorescent staining showed a decrease in GFAP and IBA1 intensity in the spinal cord along with an increase in NeuN following Ursolic acid treatment. Overexpression of MAPK1 in SNL rats led to an increase in inflammatory factors and a decrease in PWL and PWT. Furthermore, MAPK1 counteracted the pain-relieving effects of Ursolic acid in SNL rats. Ursolic acid was found to alleviate neuropathic pain in SNL rats by targeting MAPK1 and influencing gut microbiota homeostasis.

[Protective effect of vitrification and controlled slow freezing on immature testicular tissue].

OBJECTIVE: To explore and compare the current mainstream testicular tissue freezing methods, namely vitrification and controlled slow freezing, and optimize the best testicular tissue freezing methods. METHODS: Testicular tissues of 3-week-old mice and <2-year old prepubertal cynomophage monkeys were collected and cut to 6-26 mm3, and divided into three groups: Fresh group, vitrification group and controlled slow freezing group were resuscitated after 5-7 days of freezing. HE staining, immunofluorescence staining, TUNEL staining and Western blot were used to evaluate the frozen-thawed testicular tissue. RESULTS: 1. In the testes of C57BL6/J mice, the expression level of spermatogonial stem cell marker UCHL1 in the controlled slow freezing group was higher than that in the vitrification group, and the content of apoptotic cells (TUNEL+ cells) was lower than that in the vitrification group. 2. In the testicular tissue of cynomolgus monkeys, the expression levels of spermatogonial stem cell markers UCHL1 and cell proliferation marker PCNA in the CSF group were higher than those in the vitrification group. CONCLUSION: Both vitrification and CSF can successfully preserve the testes of immature mice and cynomolgus monkeys before puberty. However, in the vitrification, there are more frozen damaged areas in the testicular tissue with the frozen volume of 6-26mm3, which may affect the cryopreservation of spermatogonial stem cells in the testicular tissue.