Retraction Note to: microRNA-128 mediates CB1 expression and regulates NF-KB/p-JNK axis to influence the occurrence of diabetic bladder disease

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s12967-021-02719-3

A Method to Isolate Pericytes From the Mouse Urinary Bladder for the Study of Diabetic Bladder Dysfunction

Purpose: Pericytes surround the endothelial cells in microvessels and play a distinct role in controlling vascular permeability and maturation. The loss of pericyte function is known to be associated with diabetic retinopathy and erectile dysfunction. This study aimed to establish a technique for the isolation of pericytes from the mouse urinary bladder and an <i>in vitro</i> model that mimics <i>in vivo</i> diabetic bladder dysfunction.Methods: To avoid contamination with epithelial cells, the urothelial layer was meticulously removed from the underlying submucosa and detrusor muscle layer. The tissues were cut into multiple pieces, and the fragmented tissues were settled by gravity into collagen I-coated culture plates. The cells were cultured under normal-glucose (5 mmol/L) or high-glucose (30 mmol/L) conditions, and tube formation, cell proliferation, and TUNEL assays were performed. We also performed hydroethidine staining to measure superoxide anion production.Results: We successfully isolated high-purity pericytes from the mouse urinary bladder. The cells were positively stained for platelet-derived growth factor receptor-β and NG2 and negatively stained for smooth muscle cell markers (desmin and myosin) and an endothelial cell marker (CD31). The number of tubes formed and the number of proliferating cells were significantly lower when the pericytes were exposed to high-glucose conditions compared with normal-glucose conditions. In addition, there were significant increases in superoxide anion production and the number of apoptotic cells when the pericytes were cultured under high-glucose conditions.Conclusions: To the best of our knowledge, this is the first study to isolate and culture pericytes from the mouse urinary bladder. Our model would be a useful tool for screening the efficacy of therapeutic candidates targeting pericyte function in diabetic bladder dysfunction and exploring the functional role of specific targets at the cellular level.

Ossabaw Pig Demonstrates Detrusor Fibrosis and Detrusor Underactivity Associated with Oxidative Stress in Metabolic Syndrome

Metabolic Syndrome (MetS) has detrimental effects on the bladder, including detrusor underactivity. The progression and mechanism of disease are poorly understood. A swine model for diabetic bladder dysfunction (DBD) was established because of the pig's human-sized bladder and its ability to develop MetS by dietary modification alone. The hypothesis of this study is that this swine model will demonstrate oxidative stress associated with MetS, which contributes to both bladder fibrosis and detrusor underactivity (DU). Ossabaw pigs underwent dietary modification consisting of a hypercaloric, atherogenic diet for 10 mo to induce MetS, and were compared with a group of control (lean) pigs. Urodynamic studies were performed in both groups to confirm DU. Thiobarbituric acid reactive substances (TBARS) detected in the urine were used to measure oxidative stress activity in the urinary tract, and urinary IL17a was used to detect profibrotic activity. MetS was confirmed by assessing body weight, blood pressure, glucose tolerance, total cholesterol, and triglycerides. The MetS group exhibited an increase in the relative levels of urinary TBARS and IL17a. Bladder pressures at capacity were lower in the MetS group, suggesting DU. Histologic analysis of a cohort of control (lean) and MetS pigs revealed that as compared with the control pigs, the MetS pigs had significantly more collagen in the muscularis layer, but not in the submucosa or mucosa layer. In conclusion, the Ossabaw pig model for diet-induced MetS is associated with oxidative stress and profibrotic activity in the bladder, which results in DU. This has previously been shown in mice and rats, but never in pigs. This novel model will better represent human MetS and DBD because the mechanism and size of the pig bladder more closely resemble that of a human, resulting in a more valid model and facilitating further study into the signaling mechanisms responsible for this impairment.

CGRP Reduces Apoptosis of DRG Cells Induced by High-Glucose Oxidative Stress Injury through PI3K/AKT Induction of Heme Oxygenase-1 and Nrf-2 Expression

Dorsal root ganglion (DRG) neurons, which are sensitive to oxidative stress due to their anatomical and structural characteristics, play a complex role in the initiation and progression of diabetic bladder neuropathy. We investigated the hypothesis that the antioxidant and antiapoptotic effects of CGRP may be partly related to the expression of Nrf2 and HO-1, via the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, thus reducing apoptosis and oxidative stress responses. This study shows that CGRP activates the PI3K/AKT pathway, thereby inducing increased expression of Nrf2 and HO-1 and resulting in the decrease of reactive oxygen species and malondialdehyde levels and reduced neuronal apoptosis. These effects were suppressed by LY294002, an inhibitor of the PI3K/AKT pathway. Therefore, regulation of Nrf2 and HO-1 expression by the PI3K/AKT pathway plays an important role in the regulation of the antioxidant and antiapoptotic responses in DRG cells in a high-glucose culture model.