Effect of irradiation on the expression of E-cadherin and β-catenin in early and late radiation sequelae of the urinary bladder and its modulation by NF-κB inhibitor thalidomide

Intravesical IR-780 instillation prevents radiation cystitis by protecting urothelial integrity

PURPOSE

To explore an efficient preventive strategy for radiation cystitis.

METHODS

We instilled IR-780 into the bladders of rats 1 h before bladder irradiation, and its bio-distribution was observed at different times. Bladders were then examined for pathogenic alterations and inflammation levels by day 3 and week 12 postirradiation, and the functional characteristics of the bladder were tested via cystometry by week 12. Human uroepithelial sv-huc-1 cells were used to determine the effect of IR-780 on cell viability, regardless of irradiation. We measured the intracellular levels of oxidative stress, DNA damage, apoptosis proportion, and the expression of antioxidant proteases and apoptotic caspases in IR-780 pretreated cells after radiation.

RESULTS

IR-780 is localized in the urothelium after intravesical instillation in vivo. Ionizing radiation could induce acute impairment of the bladder urothelium and inflammation in the bladder on day 3. Fibrosis of the irradiated bladder progressed and eventually affected voiding function at 12 weeks. Treatment with IR-780 before irradiation ameliorated these changes. In vitro, IR-780 protected against cell viability and apoptosis of sv-huc-1 cells after irradiation. Additionally, IR-780 may assist in eliminating reactive oxygen species and repairing irradiation-induced DNA damage.

CONCLUSION

Our data indicate that IR-780 can be used before irradiation to prevent acute urinary mucosal injury and late bladder dysfunction. Moreover, early urothelial impairment plays a significant role in radiation cystitis development.

From the Matrix to the Nucleus and Back: Mechanobiology in the Light of Health, Pathologies, and Regeneration of Oral Periodontal Tissues

Among oral tissues, the periodontium is permanently subjected to mechanical forces resulting from chewing, mastication, or orthodontic appliances. Molecularly, these movements induce a series of subsequent signaling processes, which are embedded in the biological concept of cellular mechanotransduction (MT). Cell and tissue structures, ranging from the extracellular matrix (ECM) to the plasma membrane, the cytosol and the nucleus, are involved in MT. Dysregulation of the diverse, fine-tuned interaction of molecular players responsible for transmitting biophysical environmental information into the cell's inner milieu can lead to and promote serious diseases, such as periodontitis or oral squamous cell carcinoma (OSCC). Therefore, periodontal integrity and regeneration is highly dependent on the proper integration and regulation of mechanobiological signals in the context of cell behavior. Recent experimental findings have increased the understanding of classical cellular mechanosensing mechanisms by both integrating exogenic factors such as bacterial gingipain proteases and newly discovered cell-inherent functions of mechanoresponsive co-transcriptional regulators such as the Yes-associated protein 1 (YAP1) or the nuclear cytoskeleton. Regarding periodontal MT research, this review offers insights into the current trends and open aspects. Concerning oral regenerative medicine or weakening of periodontal tissue diseases, perspectives on future applications of mechanobiological principles are discussed.