[The effect of the AIM2 inflammasome in noise-induced cognitive dysfunction in rats].

Objective: To explore the effect of the absent in melanoma 2 (AIM2) -mediated neuroinflammation in noise-induced cognitive dysfunction in rats. Methods: In April 2023, sixteen male Wistar rats were randomly divided into control group and noise group, with 8 rats in each group. The rats in the noise group were placed in 50 cm×50 cm×40 cm transparent boxes and exposed to 100 dB (A) white noise with a sound pressure level of 100 dB (A) (4 h/d for 30 d) . At the same time, rats in the control group were kept in similar boxes with environmental noise less than 60 dB (A) . After 30 days of noise exposure, the Morris water maze experiment was applied to test the learning and memory abilities of the rats; the pathological morphology of hippocampal tissues was observed by Hematoxylin-Eosin (HE) staining. Western blot was used to detect the protein expression levels of AIM2, cysteinyl aspartate specific proteinase-1 (caspase-1) , apoptosis-associated speck-like protein (ASC) , interleukin-1ß (IL-1ß) , IL-18, ionic calcium-binding articulation molecule-1 (Iba-1) , and glial fibrillary acidic protein (GFAP) . The expression of both Iba-1 and GFAP in hippocampal tissue was assessed by immunohistochemical staining. The co-localization of AIM2 with Iba-1 or GFAP was determined by immunofluorescence double staining. Results: Compared with the control group, the escape latency of rats in the noise group was increased by 16.29 s, 17.71 s, and 20.26 s on days 3, 4, and 5, respectively. On day 6, the noise-exposed rats spent shorter time in the target quadrant and had fewer times in crossing the platform[ (7.25±2.27) s and (1.13±0.64) times] than the control group[ (15.64±3.99) s and (4.25±2.12) times] (P<0.05) . After noise exposure, hippocampal neurons of rats displayed marked nuclear hyperchromatic and pyknosis phenomenon. The noise-exposed rats had higher numbers of both microglia and astrocytes (27.00±2.65 and 43.33±5.51) in the DG area of the hippocampus relative to the control group (14.67±3.06 and 20.00±4.58) (P<0.05) . Moreover, the glial cells in the noise group had larger cell cytosol with more and thicker branches. The protein expression levels of inflammatory cytokines Cleaved-IL-1ß and Cleaved-IL-18 in the hippocampus of rats in the noise group (1.55±0.19 and 1.74±0.12) were significantly higher than the control group (1.00±0.11 and 1.00±0.13) (P<0.05) . After noise exposure, the protein expression levels of AIM2, Cleaved-Caspase-1 and ASC (1.19±0.09, 1.34±0.07 and 1.14±0.01) were higher than the control group (1.00±0.07, 1.00±0.14 and 1.00±0.06) and differences between the two groups were statistically significant (P<0.05) . A significant increase in the number of cells co-localizing AIM2 with Iba-1 or GFAP in the noise group (28.67±4.04 and 40.67±5.13) compared with the control group (15.67±4.04 and 17.67±3.79) , and statistically significant differences were observed between the two groups (P<0.05) . Conclusion: Noise exposure may activate the AIM2 inflammasome in hippocampal glial cells of rats, releasing excessive inflammatory cytokines and causing neuroinflammation that damages neurons.

[The mechanism and role of autologous peritoneum transplantation to enterocystoplasty in porcine model].

Objective: To explore the pathological mechanism and role of autologous peritoneum transplantation onenterocystoplasty in porcine model. Methods: Randomly, four experimental female swine were chosen, and each of their body weight was 28-33 kg. By intravenous anesthesia, the transplantation of autologous peritoneum for bladder reconstruction operation was carried out (to transplant the peritoneum onto an ileum segment of which the mucosa and submucosa had been removed. These flaps were used to mend and augment the bladder by suturing the edge of detective bladders). After removal of ureteral catheters and balloon catheter at day 5 respectively, their voiding behaviors were monitored, and respectively 2 swine were euthanized at week 3/6 for routine pathology, immunohistochemistry, and electron microscopic examinations. Results: Four swine underwent reconstruction, but none died for complications such as peritonitis, ileus and urinary fistula. The length of ileum was 35 cm, and the area of peritoneum was 15 cm×10 cm. Voiding behaviorsof the swine were normal, with clear urine after removal of their catheters. At autopsy, reconstructed bladders were healthy. Pathological examination showed the neobladder had been covered by continuous urothelium while the peritoneum disappeared without ileal mucosa regrowth or residual. Scanning electron microscope showed that the transitional cells of neobladder of swine were complete and orderly, and urothelium around suture border was continuous withoutmalposition. Conclusions: In porcine model, autologous peritoneal transplantation witnessed no immune rejection response for itself, which was replaced by crawling transitional epithelium around anastomosis, rather than by metaplasia.