Immunohistochemical Expression of Cyclin D1, Cytokeratin 20, and Uroplakin III in Proliferative Urinary Bladder Lesions Induced by o-Nitroanisole in Fischer 344/N Rats

A new discovery of polystyrene microplastics toxicity: The injury difference on bladder epithelium of mice is correlated with the size of exposed particles

Microplastics (MPs), as widespread hazardous substances in the environment, can cause potential adverse effects on biological health. However, reports on the toxic effects of different diameters MPs on urinary system are limited. Here, we investigated the types and mechanisms of damage to mice bladder epithelial cells treated with diameter (1-10 μm and 50-100 μm) polystyrene microplastics (PS-MPs). The results showed that exposure to PS-MPs of both diameters resulted in necroptosis and inflammation to bladder epithelium. However, 1-10 μm PS-MPs posed more severe necroptosis and 50-100 μm PS-MPs led to a higher degree of inflammatory injury at the same exposure concentration. Mechanistically, PS-MPs were found to induce necroptosis as well as p-NFκB-mediated inflammation by triggering oxidative stress and excessive release of reactive oxygen species (ROS). Furthermore, N-Acetyl-l-cysteine (NAC) attenuated the toxic effects of PS-MPs on bladder epithelial cells. In conclusion, our study demonstrated for the first time that PS-MPs caused necroptosis and inflammation in mice bladders tissues, and the difference of injury correlates with the size of PS-MPs particles.

Urothelial Proliferation of Unknown Malignant Potential Involving the Bladder: Histopathologic Features and Risk of Progression in De Novo Cases and Cases With Prior Neoplasia

CONTEXT.—

Urothelial proliferation of unknown malignant potential (UPUMP) is a 2016 World Health Organization classifier that encompasses prior categories of flat and papillary urothelial hyperplasia. In addition, UPUMP occurs in settings of both de novo and prior bladder neoplasia.

OBJECTIVE.—

To identify UPUMP features associated with subsequent neoplastic development.

DESIGN.—

Sixty-eight patients were identified from the archives, including 26 patients with de novo and 42 patients with prior bladder neoplasia. Patient slides and clinical course were reviewed.

RESULTS.—

Patients with de novo UPUMP were detected through clinical findings (26/26; 100%), whereas surveillance cystoscopy primarily detected UPUMP in patients with prior neoplasia (29/42; 69%). Histopathologic criteria evaluated included urothelial hyperplasia, urothelial cytology, vascular ingrowth, denudation, inflammation, edema, and fibrosis. Mean clinical follow-up was 68.9 months in patients with de novo neoplasia and 69.5 months in patients with prior neoplasia. Subsequent neoplasia developed in 4 of 26 (15.4%) of patients with de novo UPUMP and was associated with cystoscopic papillary appearance (P = .02) or microscopic thin papillary ingrowths or papillations (P = .02; median time to progression, 4.1 months). Of 42 patients with prior neoplasia, 17 (40.5%) had subsequent neoplasia, significantly associated with an absence of prominent lamina propria edema (P < .001; median time to progression, 11.0 months). A higher rate of progression to high-grade disease was present in patients with a prior neoplasia versus those with de novo disease (58.9% versus 25%).

CONCLUSIONS.—

Urothelial proliferation of unknown malignant potential shows subsequent risk of neoplastic development of 17% in patients with de novo disease and 40% in patients with prior neoplasia. The greatest risk of progression is associated with early papillary formation.