Exosomes from miR-23 Overexpressing Stromal Cells Suppress M1 Macrophage and Inhibit Calcium Oxalate Deposition in Hyperoxaluria Rat Model.

Purpose: To investigate whether ADSC-derived miR-23-enriched exosomes could protect against calcium oxalate stone formation in a hyperoxaluria rat model. Methods: An ethylene glycol- (EG-) induced hyperoxaluria rat model and an in vitro model of COM-induced HK-2 cells coculturing with RAW264.7 cells were established to explore the protective mechanisms of ADSC-derived miR-23-enriched exosomes. Results: The results showed that treatment with miR-23-enriched exosomes from ADSCs protected EG-induced hyperoxaluria rats, and cell experiments confirmed that coculturing with miR-23-enriched exosomes alleviated COM-induced cell autophagy. Overexpressed miR-23 suppressed M1 macrophage polarization by inhibiting IRF1 expression. Furthermore, the predicted binding site between the IRF1 messenger RNA 3'-untranslated region (3'-UTR) and miR-23 was confirmed by the dual-luciferase reporter assay. Conclusion: In conclusion, our research gave the first evidence that ADSC-derived miR-23-enriched exosomes affected the polarization of M1 macrophages by directly inhibiting IRF1 and protecting against calcium oxalate stone formation in a hyperoxaluria rat model.

Cystine crystal-induced reactive oxygen species associated with NLRP3 inflammasome activation: implications for the pathogenesis of cystine calculi.

PURPOSE: To investigate whether cystine crystal-induced production of reactive oxygen species (ROS) and activation of NLRP3 inflammasome contribute to cystine calculi formation. METHODS: Slc7a9-knockout rats were created as cystine calculi animal models. Kidney histological examination using TEM and immunohistochemistry were performed. The protein expression of NLRP3 and IL-1ß and the concentrations of oxidative stress markers such as ROS, MDA and H2O2 in kidney tissues were estimated. In parallel, HK-2 human renal proximal tubule cells were exposed to cystine crystals and NAC treatment. The protein and mRNA expression levels of NLRP3 were evaluated. Finally, cell apoptosis and cystine crystal adherence were also assessed. RESULTS: Activation of the NLRP3 inflammasome and marked elevations in MDA, H2O2 and ROS levels were observed both in vivo and in vitro. In particular, the protein and mRNA expression of NLRP3 was significantly increased by cystine crystals, but could be restored by an inhibitor of ROS. In addition, cell apoptosis and cystine crystal adherence were promoted by the NLRP3 inflammasome. The expression of CD44, OPN and HA in HK-2 cells was markedly increased by cystine crystals, but could be decreased by NLRP3 siRNA treatment. CONCLUSION: Notably, we found that the activation of NLRP3 by cystine crystal-induced ROS production was of major importance in the pathogenesis of cystine calculi formation.

Ceftriaxone Calcium Crystals Induce Acute Kidney Injury by NLRP3-Mediated Inflammation and Oxidative Stress Injury.

OBJECTIVE: To investigate the role of inflammatory reactions and oxidative stress injury in the mechanisms of ceftriaxone calcium crystal-induced acute kidney injury (AKI) both in vivo and in vitro. METHODS: Male Sprague Dawley rats were randomly divided into five groups of ten each according to different concentrations of ceftriaxone and calcium. Based on the levels of serum creatinine (Scr) and blood urea nitrogen (BUN), the AKI group was chosen for the subsequent experiments. Kidney histological examination and immunohistochemistry were performed. The expression of NLRP3 and IL-1ß protein and the concentrations of oxidative stress markers such as ROS, MDA, and H2O2 in kidney tissues were estimated. In parallel, HK-2 human renal proximal tubule cells were exposed to ceftriaxone calcium crystals. The mRNA expression levels of NLRP3 and IL-1ß and the concentrations of oxidative stress markers were evaluated. Finally, cell viability and rat survival were also assessed. RESULTS: The results showed that significantly increased Scr and BUN levels, consistent with morphological changes and kidney stones, were found in the rats that received the highest concentration of ceftriaxone (1000 mg/kg) combined with calcium (800 mg/kg). The activation of the NLRP3 inflammasome axis and the marked elevation of MDA, H2O2, and ROS levels were observed both in vivo and in vitro. High expression of Nrf2, HO-1, and NQO1 was also documented. In addition, cell apoptosis and rat mortality were promoted by ceftriaxone calcium crystals. CONCLUSIONS: Notably, we found that ceftriaxone-induced urolithiasis was associated with a high risk of AKI and NLRP3-mediated inflammasome and oxidative stress injury were of major importance in the pathogenesis.

Protective effect of salvianolic acid B against oxidative injury associated with cystine stone formation.

The aim of this study was to investigate the role of oxidative stress in cystine crystal formation and whether salvianolic acid B, a natural antioxidant, could prevent cystine-mediated oxidative injury in vivo and in vitro. The levels of oxidative stress and antioxidase activity in cystine stone patients were assessed. Then, the oxidative stress exerted by cystine on human kidney-2 (HK-2) cell viability and biochemical parameters including antioxidase activity and antioxidant protein expression were evaluated, and the protective action of salvianolic acid B was also examined. Finally, salvianolic acid B was tested to determine whether it could prevent or reduce renal crystal formation in Slc7a9 knockout mice. The activity levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were decreased, and the amount of malondialdehyde (MDA) was increased in patients with cystine stones compared with people without cystine stones (p < 0.05). Significant reductions in cell viability, antioxidase activity and antioxidant protein expression levels were found in the cystine group compared with controls. However, such oxidative injuries were prevented by salvianolic acid B. In the animal study, loose crystals with white spots were seen in the renal parenchyma, bilateral renal pelvis and bladders in the Slc7a9 knockout group. In contrast, no renal crystals were seen in the control group, and markedly fewer crystals with significantly higher antioxidase activity and diminished oxidative stress were detected in the salvianolic acid B group. Cystine cytotoxicity in vitro and cystine stone formation in vivo were associated with oxidative stress, and salvianolic acid B could protect against cystine stone-induced injury.

Sunitinib as first-line neoadjuvant therapy in two patients with rectal stromal tumors.

In the treatment of rectal stromal tumors, which account for approximately 5% of gastrointestinal stromal tumors, molecular-targeted neoadjuvant therapy should be considered if the tumor is too large to achieve R0 grade resection or multiple visceral resection is required. Currently, imatinib is generally recommended as the first-line agent for such therapy. Although it has been reported that neoadjuvant therapy in patients experiencing imatinib resistance or intolerable adverse events can be successfully achieved by switching to sunitinib, first-line use of sunitinib for neoadjuvant therapy of gastrointestinal stromal tumors has not previously been reported. In this case report, first-line sunitinib neoadjuvant therapy of two patients who had very large rectal stromal tumors at sites close to the prostate and bladder produced good clinical outcomes.