Molecular targets for the protodynamic action of cis-urocanic acid in human bladder carcinoma cells

Cis-urocanic acid improves cell viability and suppresses inflammasome activation in human retinal pigment epithelial cells

Age-related macular degeneration (AMD) is a common eye disease among the elderly, which can result in impaired vision and irreversible loss of vision. The majority of patients suffer from the dry (also known as the atrophic) form of the disease, which is completely lacking an effective treatment. In the present study, we evaluated the potential of cis-urocanic acid (cis-UCA) to protect human ARPE-19 cells from cell damage and inflammasome activation induced by UVB light. Urocanic acid is a molecule normally present in human epidermis. Its cis-form has recently been found to alleviate UVB-induced inflammasome activation in human corneal epithelial cells. Here, we observed that cis-UCA is well-tolerated also by human retinal pigment epithelial (RPE) cells at a concentration of 100 μg/ml. Moreover, cis-UCA was cytoprotective and efficiently diminished the levels of mature IL-1β, IL-18, and cleaved caspase-1 in UVB-irradiated ARPE-19 cells. Interestingly, cis-UCA also reduced DNA damage, whereas its effect against ROS production was negligible. Collectively, cis-UCA protected ARPE-19 cells from UVB-induced phototoxicity and inflammasome activation. This study indicates that due to its beneficial properties of preserving cell viability and preventing inflammation, cis-UCA has potential in drug development of chronic ocular diseases, such as AMD.

The Role of DmCatD, a Cathepsin D-Like Peptidase, and Acid Phosphatase in the Process of Follicular Atresia in Dipetalogaster maxima (Hemiptera: Reduviidae), a Vector of Chagas' Disease

In this work, we have investigated the involvement of DmCatD, a cathepsin D-like peptidase, and acid phosphatase in the process of follicular atresia of Dipetalogaster maxima, a hematophagous insect vector of Chagas' disease. For the studies, fat bodies, ovaries and hemolymph were sampled from anautogenous females at representative days of the reproductive cycle: pre-vitellogenesis, vitellogenesis as well as early and late atresia. Real time PCR (qPCR) and western blot assays showed that DmCatD was expressed in fat bodies and ovaries at all reproductive stages, being the expression of its active form significantly higher at the atretic stages. In hemolymph samples, only the immunoreactive band compatible with pro-DmCatD was observed by western blot. Acid phosphatase activity in ovarian tissues significantly increased during follicular atresia in comparison to pre-vitellogenesis and vitellogenesis. A further enzyme characterization with inhibitors showed that the high levels of acid phosphatase activity in atretic ovaries corresponded mainly to a tyrosine phosphatase. Immunofluorescence assays demonstrated that DmCatD and tyrosine phosphatase were associated with yolk bodies in vitellogenic follicles, while in atretic stages they displayed a different cellular distribution. DmCatD and tyrosine phosphatase partially co-localized with vitellin. Moreover, their interaction was supported by FRET analysis. In vitro assays using homogenates of atretic ovaries as the enzyme source and enzyme inhibitors demonstrated that DmCatD, together with a tyrosine phosphatase, were necessary to promote the degradation of vitellin. Taken together, the results strongly suggested that both acid hydrolases play a central role in early vitellin proteolysis during the process of follicular atresia.

Antitumor effects of cis-urocanic acid on experimental urothelial cell carcinoma of the bladder

PURPOSE

We determined the effect of protodynamic therapy against bladder cancer cells in vitro and in vivo. We investigated cis-urocanic acid in rat bladder cancer cell cultures and in an orthotopic rat urothelial carcinoma model to assess its safety and antiproliferative activity.

MATERIALS AND METHODS

The rat bladder cancer cell line AY-27 was exposed to cis-urocanic acid (BioCis Pharma, Turku, Finland) at pH 6.5 or 7.4 for 2 hours. Cell viability was measured by colorimetric assay at 24 and 48 hours. For in vivo experiments AY-27 cells were instilled into the acid treated bladder of 17 rats. After 4, 7 and 10 days 14 rats were treated intravesically with cis-urocanic acid 6% (weight per volume) or vehicle. Rats were sacrificed on day 12 and the bladders were dissected. Immunohistochemical staining was done to assess apoptosis (caspase-3) and cell proliferation (Ki-67) in vivo.

RESULTS

Cis-urocanic acid caused dose dependent, pH dependent inhibition of AY-27 cell proliferation, showing the protodynamic action at concentrations of 0.5% and 1%. At higher cis-urocanic acid doses complete cell death was observed. All tumors detected in animals treated with vehicle were muscle invasive (stage T2 or greater) but only 43% of tumors were muscle invasive in the cis-urocanic acid treated group (p=0.049). There was no difference in the percent of apoptotic or proliferating tumor cells between treatment groups. No signs of toxicity were observed.

CONCLUSIONS

Cis-urocanic acid showed direct antiproliferative activity against rat bladder cancer cells in vitro and antitumor effects in vivo. It may have therapeutic potential as an intravesical agent for nonmuscle invasive bladder cancer.