A model dependent difference in the expression of inflammatory markers in an animal model of BPS/ IC

Mangir N1, Guner G2, Shirinli K1, Inal- Gultekin G3

Research Type

Pure and Applied Science / Translational

Abstract Category

Pelvic Pain Syndromes

Abstract 249
Microbiology and Biomaterials
Scientific Podium Short Oral Session 24
Friday 25th October 2024
11:30 - 11:37
Hall N102
Painful Bladder Syndrome/Interstitial Cystitis (IC) Mathematical or statistical modelling Pathophysiology Basic Science
1. Hacettepe University School of Medicine, Department of Urology, Ankara, TURKEY, 2. Hacettepe University School of Medicine, Department of Pathologyy, Ankara, TURKEY, 3. Okan University School of Medicine, Department of Physiology, Istanbul, Turkey
Presenter
Links

Abstract

Hypothesis / aims of study
Bladder pain syndrome/interstitial cystitis (BPS/IC) is a debilitating pain syndrome characterised by a pain, pressure or discomfort perceived to be related to the urinary bladder. Despite its well recognised impact on the patients, the society and the healthcare systems, effective treatments are still lacking for BPS/ ICS. The power of computers can potentially advance BPS/ IC research by analyzing complex biologic data at cellular and molecular levels.
In this study, we have studied the molecular expression of several bioinformatically defined genes in a disease model of rats with BPS/ IC.
Study design, materials and methods
A bioinformatic analysis revealed  21 differentially expressed genes (DEG) in patients with and without Hunner’ s lesion disease and controls. Out of the 21 DEGs, 7 (AQP9, CHI3L1, ITGB2, MMP9, MCP1, BTNL2, HLA-DQB1) were selected for further analysis in the animal models. 
BPS/ IC was induced using the Lipopolisaccaride (LPS) and Cyclophosphamide (CYP) models in rats. Female rats at reproductive age received 1 mg/ml of LPS from E. Coli intravesically for the LPS group (n=8) and 75 mg/kg cyclophosphamide intraperitoneally for the CYP group (n=8) on days 0, 3 and 5.  An intravesical (n=6) and intraperitoneal (n=3) injection of PBS groups were also used. Experiments ended on day 7 and the bladder tissues were removed. After gross examination tissues were cut into half and sent for histologic and molecular analysis.
Results
Gross examination of the bladder tissues confirmed thickened bladder Wall with inflammed mucosa and hemorrhagic areas and areas with increased vascularity in LPS and CYP groups, compared to controls.   Hematoxylin-eosin stained sections showed focal acute inflammation in 2 members of the LPS group (Figure 1A) focal suburothelial hemorrhage and denudation in 4 members of the CYC group (Figure 1B).
Gene expression with PCR showed a model dependent expression of the selected genes. In the LPS group, expression of all genes, except HLA-DQB1, was higher compared to control. Whereas in CYC group, expression of the genes were lower or did not change compared to controls (Figure 2). It appears that intraperitoneal administration of CYC in rats, led to a decrease in the expression of these genes suggesting an supressive effect on the immune system and therefore is not a suitable model for studying inflammatory markers in this disease. In the LPS model, the inflammation appears to be triggered locally via administration of the bacterial LPS into the bladder.
Interpretation of results
Genes coding surface markers of inflammatory cells have been found to be expressed differently in the two most commonly used animal models representing Hunner lesion disease BPS/ IC. This highlights the importance of meticulous use of animal models in BPS/ IC research.  In case of Hunner lesion disease, both CYC and LPS models reproduce bladder inflammation in gross examination however there is a distinct difference in expression of some immunological markers.
Concluding message
We have demonstrated a model dependent difference in expression of investigated adhesion molecules  that have previously been studied as promising biomarkers.
Figure 1 Hematoxylin-eosin stain showing the inflammatory infiltrate in the rat bladder. (A) LPS-induced cystitis group shows focal acute inflammation with intraepitelial (intraurothelial) neutrophils (blue arrows), intraepithelial erythrocytes (red arrow) and a s
Figure 2 Comparison of gene expression profiles in CYC and LPS models of BPS/ IC. (CYC: Cyclophosphamide; LPS: Lipopolisaccaride; *: p value <0.05 compared to control)
Disclosures
Funding Authors do not have any conflicts of interest Clinical Trial No Subjects None
Citation

Continence 12S (2024) 101591
DOI: 10.1016/j.cont.2024.101591

25/11/2024 21:13:40