The expression and distribution of TACAN in human and rat bladders.

Objectives: A lot of ion channels participate in the regulation of bladder function. TACAN, a new mechanosensitive ion channel, was first discovered in 2020. TACAN has been found to be expressed in many tissues, such as the dorsal root ganglia (DRG) and adipose tissue. However, it is unclear whether or not TACAN is expressed in the bladder. In this work, we decided to study the expression and distribution of TACAN in human and rat bladders. Meanwhile, the expression of TACAN in the rat model of interstitial cystitis/bladder pain syndrome (IC/BPS) was studied.

Methods: Human bladder tissues were obtained from female patients. Cyclophosphamide (CYP) was used to build the rat model of IC/BPS. Real-time polymerase chain reaction, agarose gel electrophoresis, and western blotting were used to assess the expression of TACAN in human and rat bladders. Immunohistochemistry and immunofluorescence were used to observe the distribution of TACAN in human and rat bladders. Hematoxylin-eosin stain, withdrawal threshold, and micturition interval were used to evaluate animal models.

Results: The results of agarose gel electrophoresis and western blotting suggested that TACAN was expressed in human and rat bladders. Immunohistochemical results suggested that TACAN showed positive immunoreaction in the urothelial and detrusor layers. The immunofluorescence results indicated that TACAN was co-stained with UPKIII, α-SMA, and PGP9.5. The IC/BPS model was successfully established with CYP. The mRNA and protein expression of TACAN was upregulated in the CYP-induced rat model of IC/BPS.

Conclusions: TACAN was found in human and rat bladders. TACAN was mainly distributed in the urothelial and detrusor layers and bladder nerves. The expression of TACAN was upregulated in the CYP-induced rat model of IC/BPS. This new discovery will provide a theoretical basis for future research on the function of TACAN in the bladder and a potential therapeutic target for IC/BPS.