Poly-L-lysine as an Effective and Safe Desquamation Inducer of Urinary Bladder Epithelium

Establishment of Mouse Orthotopic Urinary Bladder Tumor Model and Its Analysis by Light and Electron Microscopy

Mouse tumor models are an important tool in cancer research, and the orthotopic cancer cell transplantation model is the most widely used among them. Methods for establishing tumor models may differ in many ways, including the selection of cancer cell lines and the type of urinary bladder pretreatment. Here, we describe our mouse orthotopic bladder tumor model using a labeled MB49 urothelial cancer cell line and chemical pretreatment with the cationic polypeptide poly-L-lysine to traumatize the bladder epithelium. Double labeling of MB49 cancer cells by their transduction with GFP and internalization of metal nanoparticles allows the study of their implantation process from the first hours to several days after intravesical injection, as well as the analysis of developed tumors after 3 weeks. Thus, our model provides a comprehensive analysis of the early and late stages of tumor development in the bladder at the light and electron microscopic level.

The effect of amino acids on the bladder cycle: a concise review

The human bladder maintains a cycle of filling, storing, and micturating throughout an individual's lifespan. The cycle relies on the ability of the bladder to expand without increasing the intravesical pressure, which is only possible with the controlled relaxation of well-complaint muscles and the congruously organized construction of the bladder wall. A competent bladder outlet, which functions in a synchronous fashion with the bladder, is also necessary for this cycle to be completed successfully without deterioration. In this paper, we aimed to review the contemporary physiological findings on bladder physiology and examine the effects of amino acids on clinical conditions affecting the bladder, with special emphasis on the available therapeutic evidence and possible future roles of the amino acids in the treatment of the bladder-related disorders.

Does the Urothelium of Old Mice Regenerate after Chitosan Injury as Quickly as the Urothelium of Young Mice?

The aging of organisms leads to a decreased ability of tissue to regenerate after injury. The regeneration of the bladder urothelium after induced desquamation with biopolymer chitosan has been studied in young mice but not in old mice. Chitosan is a suitable inducer of urothelial desquamation because it is known to be non-toxic. We used chitosan for desquamation of urothelial cells in order to compare the dynamics of urothelial regeneration after injury between young and old mice. Our aim was to determine whether the urothelial function and structure of old mice is restored as fast as in young mice, and to evaluate the inflammatory response due to chitosan treatment. We discovered that the urothelial function restored comparably fast in both age groups and that the urothelium of young and old mice recovered within 5 days after injury, although the onset of proliferation and differentiation appeared later in old mice. Acute inflammation markers showed some differences in the inflammatory response in young versus old mice, but in both age groups, chitosan caused short-term acute inflammation. In conclusion, the restoration of urothelial function is not impaired in old mice, but the regeneration of the urothelial structure in old mice slightly lags behind the regeneration in young mice.