Application of metabolomics in urolithiasis:the discovery and usage of succinate

Urinary stone is conceptualized as a chronic metabolic disorder punctuated by symptomatic stone events.It has been shown that the occurrence of calcium oxalate monohydrate(COM)during stone formation is regulated by crystal growth modifiers.Although crystallization inhibitors have been recognized as a therapeutic modality for decades,limited progress has been made in the discovery of effective modifiers to intervene with stone disease.In this study,we have used metabolomics technologies,a powerful approach to identify biomarkers by screening the urine components of the dynamic progression in a bladder stone model.By in-depth mining and analysis of metabolomics data,we have screened five differential metabolites.Through density functional theory studies and bulk crystallization,we found that three of them(salicyluric,gentisic acid and succinate)could effectively inhibit nucleation in vitro.We thereby assessed the impact of the inhibitors with an EG-induced rat model for kidney stones.Notably,succinate,a key player in the tricarboxylic acid cycle,could decrease kidney calcium deposition and injury in the model.Transcriptomic analysis further showed that the protective effect of succinate was mainly through anti-inflammation,inhibition of cell adhesion and osteogenic differentiation.These findings indicated that succinate may provide a new therapeutic option for urinary stones.

Procyanidins-crosslinked small intestine submucosa: A bladder patch promotes smooth muscle regeneration and bladder function restoration in a rabbit model

Currently the standard surgical treatment for bladder defects is augmentation cystoplasty with autologous tissues,which has many side effects.Biomaterials such as small intestine submucosa(SIS)can provide an alternative scaffold for the repair as bladder patches.Previous studies have shown that SIS could enhance the capacity and compliance of the bladder,but its application is hindered by issues like limited smooth muscle regeneration and stone formation since the fast degradation and poor mechanical properties of the SIS.Procyanidins(PC),a natural bio-crosslinking agent,has shown anti-calcification,anti-inflammatory and anti-oxidation properties.More importantly,PC and SIS can crosslink through hydrogen bonds,which may endow the material with enhanced mechanical property and stabilized functionalities.In this study,various concentrations of PC-crosslinked SIS(PC-SIS)were prepared to repair the full-thickness bladder defects,with an aim to reduce complications and enhance bladder functions.In vitro assays showed that the crosslinking has conferred the biomaterial with superior mechanical property and anti-calcification property,ability to promote smooth muscle cell adhesion and upregulate functional genes expression.Using a rabbit model with bladder defects,we demonstrated that the PC-SIS scaffold can rapidly promote in situ tissue regrowth and regeneration,in particular smooth muscle remodeling and improvement of urinary functions.The PC-SIS scaffold has therefore provided a promising material for the reconstruction of a functional bladder.