Demonstration of the direct impact of ketamine on urothelium using a tissue engineered bladder model

Abstract

Introduction: Ketamine is a common recreational drug. Severe lower urinary tract symptoms associated with its consumption have been reported, but little is known about the involved mechanisms. The effect of ketamine, which is excreted in urine, was evaluated by its application on an in vitro three-dimensional human tissue-engineered bladder model composed of an urothelium and a submucosa. Methods: Human urothelial cells were cultured with medium containing various concentrations of ketamine and harvested at different times to obtain growth curves. Using this model, specific activity of caspase-3 was measured to assess the level of apoptosis induced by ketamine. Finally, a human tissue-engineered bladder model was used. Urothelial cells were plated on a stromal layer made of dermal fibroblasts and incubated at the air/liquid interface to allow their differentiation. Ketamine was then put on the mature urothelium using paper or agarose vectors for 48 hours. Results: The presence of ketamine increased cells' doubling times from 1.26 days for control to 1.38 days (p = 0.14) and 1.78 days (p < 0.01) for the 0.5 mM and 1.5 mM concentrations, respectively. 5 mM and 10 mM of ketamine led to decline in the major cell population. Exposure to 5 mM ketamine induced apoptosis, confirmed by a 2.5-fold increase in capase-3 specific activity from control (p = 0.03). The structure and cellular cohesion of the urothelium on the three-dimensional model, especially in the intermediate layers, were severely affected in a concentration dependant fashion with both vectors. Conclusion:The presence of ketamine in the bladder directly damages the urothelium through the induction of apoptosis.

Innovative Human Three-Dimensional Tissue-Engineered Models as an Alternative to Animal Testing

“…The use of these two cancer models for drug testing shows the potential to reduce the need for animal testing. The bladder mucosa model has also been used to study cystitis induced by ketamine use [ 292 ].…”

Ketamine decreases cell viability of bone explants and impairs bone healing in rats

“…Ketamine on the other hand, was shown to be toxic to hepatocytes, urothelium, and neural cell [8][9][10]. Additionally, Du reported that clinically relevant concentration of ketamine induces osteoclast apoptosis and inhibits osteoclast formation from bone marrow cultures [11].…”

What urologists need to know about ketamine‐induced uropathy: A systematic review

“…Baker et al showed that ketamine‐induced toxicity to urothelial cells by high and sustained intracellular calcium ion concentration, which ultimately led to apoptosis 40 . This damage acts in a dose and time‐dependent manner, stimulating mitochondrial‐dependent and endoplasmic reticulum stress apoptosis and autophagy 41,43‐46 . Chuang et al showed that ketamine and norketamine levels were much higher in the 28‐day treated group compared to the 14‐day group.…”