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PD-1/PD-L1 inhibitors have been demonstrated to induce itch in both humans and experimental animals. However, whether the PD-1/PD-L1 pathway is involved in the regulation of chronic psoriatic itch remains unclear. This study aimed to investigate the role of the PD-1/PD-L1 pathway in imiquimod-induced chronic psoriatic itch. The intradermal injection of PD-L1 in the nape of neck significantly alleviated chronic psoriatic itch in imiquimod-treated skin. Additionally, we observed that spontaneous scratching behavior induced by imiquimod disappeared on day 21. Still, intradermal injection of PD-1/PD-L1 inhibitors could induce more spontaneous scratching for over a month, indicating that imiquimod-treated skin remained in an itch sensitization state after the spontaneous scratching behavior disappeared. During this period, there was a significant increase in PD-1 receptor expression in both the imiquimod-treated skin and the spinal dorsal horn in mice, accompanied by significant activation of microglia in the spinal dorsal horn. These findings suggest the potential involvement of the peripheral and central PD-1/PD-L1 pathways in regulating chronic itch and itch sensitization induced by imiquimod. [ABSTRACT FROM AUTHOR]

:In order to study the corronon reiistance of iitanium alloy surface microstructure in seawater, laser was used to process the microstructure on the titanrnm alloy surface,and a superhydrophobic iitanium alloy surface was obtamed by modifying it with fluoronlane. The prepared sample was immersed in ariiSisial seawater at 40 *C for one day, and the morphology, dement content, and polarization curve changes of the titanmm alloy surface microstructure before and after ariiSisial seawater immerrion were compared. The results showed that there was no change in its morphology, and the oxygen content only increased by 1.1%. However, the open iircuit potential and sflt-corrosion potential did not change before and after immerson nn artificial seawater, with values of 0. 08 V and --0. 07 Viespectivlly. This ndicates that the surface microstructure of superhydrophobic titanmm alloy has good corroson resistance nn artificial seawatee. At the same time, a new Tafll function was constructed to dynamically evaluate the corroson resistance of titanuum alloy surface microstructure nn artificial seawater,providing effective guidance for the corroson resistance evaluation of titanuum alloy surface microstructure nn seawatee. [ABSTRACT FROM AUTHOR]

Sevoflurane is an inhalation anaesthetic agent widely used in clinical settings. Despite good surgical outcomes using sevoflurane, patients frequently develop postoperative cognitive dysfunction (POCD). An enriched environment (EE), as a rehabilitation technique, could provide objects and tools to facilitate neuromotor and visual stimuli and brain activity, and is reported to improve cognitive functions. We aim to investigate the impairments of sevoflurane inhalation on cognitive function in mice and determine the benefits of EE in ameliorating POCD. Eighteen-month-old mice were exposed to sevoflurane inhalation for 2 h and then placed in standard environment (SE) or EE cages. The mice without sevoflurane exposure in standard or EE cages were used as controls. The behavioural tests include Morris water maze, Y maze and novel object recognition. Magnetic resonance imaging (MRI) was used to determine the blood circulation in the brains. The proangiogenic factors (CD31, angiopoietin-1, vascular endothelial growth factor, and N-cadherin) and neurotrophic (brain-derived neurotrophic factor, post-synaptic density protein 95) expression in hippocampus of aged mice were evaluated by Western blotting and RT-PCR analysis. Sevoflurane-exposed mice demonstrated reduced performance in learning, memory and spatial memory tests. Enriched environment improved the behavioural performance of sevoflurane-exposed animals. Sevoflurane exposure reduced the blood flow in the brains, and these effects were ameliorated by EE habitation. The EE also promoted the expression of angiogenic and neurotropic factors in sevoflurane-exposed animals. In summary, EE is effective in ameliorating the side-effects of sevoflurane exposure in aged mice.

Diabetic peripheral neuropathy (DPN) is a common complication of type 2 diabetes mellitus (T2DM) that causes peripheral and autonomic nervous system dysfunction. Dysregulation of miRNAs plays a crucial role in DPN development. However, the role of miR-503-5p in DPN remains unknown. Herein, T2DM mice (db/db) were used as a DPN model in vivo, and astrocytes isolated from db/db mice were induced with high glucose levels as a DPN model in vitro. MiR-503-5p expression was analyzed using qRT-PCR. GFAP, MCP-1, and SEPT9 protein levels were analyzed using western blotting and immunofluorescence. Luciferase assays were performed to investigate the interaction between miR-503-5p and SEPT9. We found that miR-503-5p expression decreased in the spinal cord of DPN model mice and astrocytes treated with high glucose (HG). The db/db mice displayed higher body weight and blood glucose, lower mechanical withdrawal threshold and thermal withdrawal latency, and higher GFAP and MCP-1 protein levels than db/m mice. However, tail vein injection of agomiR-503-5p remarkably reversed these parameters, whereas antigomiR-503-5p enhanced them. HG markedly facilitated GFAP and MCP-1 protein expression in astrocytes, whereas miR-503-5p mimic or inhibitor transfection markedly blocked or elevated GFAP and MCP-1 protein expression, respectively, in astrocytes with HG. SEPT9 was a target of miR-503-5p. In addition, SEPT9 protein levels were found to be elevated in db/db mice and astrocytes treated with HG. Treatment with agomiR-503-5p and miR-503-5p mimic was able to reduce SEPT9 protein levels, whereas treatment with antigomiR-503-5p and miR-503-5p inhibitor led to inhibition of the protein. Furthermore, SEPT9 overexpression suppressed the depressing effect of miR-503-5p overexpression in astrocytes subjected to HG doses. In conclusion, miR-503-5p was found to alleviate peripheral neuropathy-induced neuropathic pain in T2DM mice by regulating SEPT9 expression., (© 2024. The Author(s).)

Objective: To investigate the effect of energy intake restriction on postoperative cognitive dysfunction (POCD) after internal fixation of tibial fractures in mice., Methods: Thirty mice were divided into model groups of internal fixation of tibial fractures with 0%, 20%, 30% and 40% energy intake restriction and sham operation group (n = 6). Novel object recognition task and elevated plus maze test were used to assess the ability of recognition memory and anxiety-related behavior before and one week after surgery. The blood samples were collected from mice on days 1, 3 and 7 after surgery, and the mice were euthanized on the 8th day after surgery. RT-PCR and Western blot were employed to detect the expression of AMPK-SIRT1 pathway-related genes and proteins in the hippocampus. ELISA was used to detect the levels of inflammatory factors in the peripheral blood of mice. Hematoxylin-eosin (H&E) staining and immunofluorescence (IF) staining were used to detect the proliferation, differentiation and injury of hippocampal cells., Results: The results showed that 20% and 30% energy intake restriction significantly improved the POCD after internal fixation of tibial fractures in mice. Significantly, 30% energy intake restriction reduced the expression of AP-1, NF-κB, CD45, IBA-1, and inflammatory factors IL-1β, IL-6, IL-8 and TNF-α, and increased the expression of AMPK and SIRT1 after the operation. H&E and IF staining showed that 30% energy intake restriction reduced postoperative hippocampal neuronal damage., Conclusion: Energy intake restriction can significantly improve POCD after internal fixation of tibial fractures in mice and may provide a new treatment paradigm for POCD patients., Competing Interests: None., (AJTR Copyright © 2023.)