Prevention of Anti-microbial Peptide LL-37-Induced Apoptosis and ATP Release in the Urinary Bladder by a Modified Glycosaminoglycan

Abstract

Interstitial cystitis (IC), often referred to in combination with painful bladder syndrome, is a chronic inflammatory disease of the bladder. Current therapies primarily focus on replenishing urothelial glycosaminoglycan (GAG) layer using GAG analogs and managing pain with supportive therapies. However, the elusive etiology of IC and the lack of animal models to study the disease have been major hurdles developing more effective therapeutics. Previously, we showed an increased urinary concentration of antimicrobial peptide LL-37 in spina bifida patients and used LL-37 to develop a mouse model of cystitis that mimics important clinical findings of IC. Here we investigate (1) the molecular mechanism of LL-37 induced cystitis in cultured human urothelial cells and in mice, (2) the protective effects of GM-0111, a modified GAG, within the context of this mechanism, (3) the physiological and molecular markers that correlate with the severity of the inflammation, and (4) the protective effects of several GAGs using these biomarkers in our LL-37 induced cystitis model. We find that LL-37 quickly induces release of ATP and apoptosis in the urothelium. These changes can be inhibited by a chemically-modified GAG, GM-0111. Furthermore, we also find that GAG analogs provide varying degrees of protection against LL-37 challenge in mice. These findings suggest that GM-0111 and possibly GAG molecules prevent the development of cystitis by blocking the apoptosis and the concurrent release of ATP from the urothelium.

Insulin and the phosphatidylinositol 3-kinase signaling pathway regulate Ribonuclease 7 expression in the human urinary tract

“…Primary human urothelial cells, obtained from a 52-year-old white male, were cultured in urothelial cell medium with urothelial growth supplements (Lot#8854, ScienCell Research Laboratories, Carlsbad, CA). 65 Once reaching 80–90% confluency, cells were treated with the indicated drugs or with carrier for the specified times.…”

More than just a filler – the role of hyaluronan for skin homeostasis

“…Similarly, HA is used as scaffolding material in tissue engineering to provide three‐dimensional templates to improve cell growth and growth factor presentation . Another promising approach might be the use of cross‐linked structures with chemically modified HA that can interfere with inflammation or modify the differentiation of fibroblasts during wound healing .…”

“…and growth factor presentation (19,22,180). Another promising approach might be the use of cross-linked structures with chemically modified HA that can interfere with inflammation (181,182) or modify the differentiation of fibroblasts during wound healing (183).…”

Prevention of sinonasal inflammation by a synthetic glycosaminoglycan

“…1) previously demonstrated to be effective in attenuating inflammatory responses in rosacea,[19] initial cystitis (IC),[20,21] and periodontitis. [22] We therefore hypothesized that GM-0111 could prevent sinonasal inflammation in a mouse model of rhinosinusitis (RS).…”

“…[35,36] Employing this model and based on prior evidence, we hypothesized that GM-0111 would (1) effectively coat and penetrate the sinuses through topical, intranasal delivery and (2) prevent sinonasal inflammation by protecting the sinonasal epithelium against inflammatory cell infiltration and cell death. [21,32]. …”