Inhibition of inflammation using diacerein markedly improved renal function in endotoxemic acute kidney injured mice.

BACKGROUND: Inflammation is an important pathogenic component of endotoxemia-induced acute kidney injury (AKI), finally resulting in renal failure. Diacerein is an interleukin-1ß (IL-1ß) inhibitor used for osteoarthritis treatment by exerting anti-inflammatory effects. This study aims to investigate the effects of diacerein on endotoxemia-induced AKI. METHODS: Male C57BL/6 mice were intraperitoneally injected with lipopolysaccharide (LPS, 10 mg/kg) for 24 h prior to diacerein treatment (15 mg/kg/day) for another 48 h. Mice were examined by histological, molecular and biochemical approaches. RESULTS: LPS administration showed a time-dependent increase of IL-1ß expression and secretion in kidney tissues. Diacerein treatment normalized urine volume and osmolarity, reduced blood urea nitrogen (BUN), fractional excretion of sodium (FENa), serum creatinine and osmolarity, and protected renal function in an endotoxemic AKI mice model. In the histopathologic study, diacerein also improved renal tubular damage such as necrosis of the tubular segment. Moreover, diacerein inhibited LPS-induced increase of inflammatory cytokines, such as IL-1ß, tumor necrosis factor-α, monocyte chemoattractant protein-1 and nitric oxide synthase 2. In addition, LPS administration markedly decreased aquaporin 1 (AQP1), AQP2, AQP3, Na,K-ATPase α1, apical type 3 Na/H exchanger and Na-K-2Cl cotransporter expression in the kidney, which was reversed by diacerein treatment. We also found that diacerein or IL-1ß inhibition prevented the secretion of inflammatory cytokines and the decrease of AQP and sodium transporter expression induced by LPS in HK-2 cells. CONCLUSION: Our study demonstrates for the first time that diacerein improves renal function efficiently in endotoxemic AKI mice by suppressing inflammation and altering tubular water and sodium handing. These results suggest that diacerein may be a novel therapeutic agent for the treatment of endotoxemic AKI.

Cytoprotective effect of aquaporin 1 against lipopolysaccharide-induced apoptosis and inflammation of renal epithelial HK-2 cells.

Sepsis is the most common underlying disease of disseminated intravascular coagulation. Acute kidney injury is a common and serious complications of sepsis. In the present study, a lipopolysaccharide (LPS)-induced human proximal tubule cell line (HK-2 cells) was selected as an in vitro model of septic acute kidney injury. The aim of the present study was to investigate whether aquaporin 1 (AQP-1) has a cytoprotective role in LPS-induced HK-2 cells. HK-2 cells were treated with 0-16 µg/ml LPS for 0-24 h to establish the in vitro model of sepsis. The results demonstrated that AQP-1 levels were the lowest of the eight AQP genes expressed in LPS-induced HK-2 cells. Prior to LPS treatment, HK-2 cells were transfected with pcDNA-AQP-1 or small interfering-AQP-1 and cell counting kint-8 and flow cytometry assays were performed to assess cell viability and apoptosis rate, respectively. Changes in the expression of proinflammatory cytokines and chemokines, as well as important factors in the p38, extracellular signal-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK) pathways, were assessed using reverse transcription-quantitative polymerase chain reaction, western blotting and ELISA, respectively. LPS treatment reduced viability, increased apoptosis and upregulated the expression of proinflammatory cytokines and chemokines in HK-2 cells. AQP-1 overexpression significantly reversed the effects of LPS and downregulated the expression of tumor necrosis factor-α, interleukin (IL)-8, IL-1ß and monocyte chemoattractant protein-1. The p38, ERK1/2 and JNK pathways were activated by LPS; however, the p38 and ERK1/2 pathways were blocked in AQP-1-overexpressing cells. AQP-1 overexpression was demonstrated to confer a survival advantage to LPS-injured HK-2 cells by controlling cell viability, apoptosis and inflammation, possibly via modulation of the p38 and ERK1/2 pathways. The results of the present study suggest that AQP-1 may be an effective treatment for acute kidney injury caused by sepsis.

Protective effects of LM22A-4 on injured spinal cord nerves.

OBJECTIVE: The goal of this study was to elucidate the protection by and potential mechanisms of LM22A-4, a specific agonist of tyrosine kinase receptor B, against spinal cord injury (SCI). METHODS: Spinal cord trauma was induced by the application of vascular clips to the dura of mice via a four-level T7-T11 laminectomy. Thirty minutes after the injury, an abdominal injection of LM22A-4 (at dosages of 10 mg/kg and 15 mg/kg) or an equal volume of solvent was provided. Twenty-four hours after SCI, a Western blot was performed to examine the expression of p-TrkB, p-Akt, p-ERK, cleaved-caspase-3, and Bcl-2; a TUNEL assay and Nissl staining were performed to study apoptosis and the survival of neurons. In addition, another batch of mice was allowed to live for 14 days after the SCI treatment, during which the LM22A-4 was provided at the same time each day and the neurological function was assessed. RESULTS: Spinal cord injury in mice resulted in severe trauma characterized by tissue damage and apoptosis. Treatment of the mice with LM22A-4 (10 mg/kg) significantly reduced the degree of tissue injury (histological score) and apoptosis (TUNEL staining and caspase-3 and Bcl-2 expression) compared with vehicle treated group (P < 0.05). In a separate set of experiments, chronic treatment with LM22A-4 also significantly ameliorated the recovery of limb function (P < 0.05). CONCLUSION: This study provides an experimental evidence that LM22A-4 reduces the development of tissue injury associated with spinal cord trauma, and activation of the activity of TrkB may represent a novel approach for the therapy of spinal cord trauma.

Clinical implications of CIP2A protein expression in breast cancer.

The aim of this work is to study the expression and regulatory effects of CIP2A protein in breast cancer and the correlation between CIP2A protein expression and the prognosis of breast cancer. The CIP2A protein level was detected by immunohistochemistry staining. The relationship between CIP2A protein and clinicopathological parameters of breast cancer was determined. It was observed that 448 (35.00 %) of the 1,280 cases positively expressed CIP2A protein. Univariate analysis indicated that CIP2A expression was related to histological grade, lymph node metastasis, distant metastasis, and triple-negative breast cancer (P = 0.001, 0.001, 0.001, and 0.001, respectively). Spearman correlation analysis showed that CIP2A expression has line correlation with histological grade, lymph node metastasis, distant metastasis, triple-negative breast cancer, and TNM stage (P = 0.03, 0.001, 0.008, 0.001, and 0.001, respectively). After multivariate analysis, tumor size, histological grade, lymph node metastasis, triple-negative breast cancer, distant metastasis, and TNM stage were related to CIP2A expression (P = 0.035, 0.001, 0.028, 0.001, 0.001, and 0.001, respectively). CIP2A expression also significantly related to chemotherapeutic sensitivity of breast cancer in the neoadjuvant chemotherapy. In the Cox regression test, histological grade, lymph node metastasis, triple-negative breast cancer, and TNM stage were detected as the independent prognostic factors (P = 0.001, 0.006, 0.01, 0.011, and 0.001, respectively). CIP2A expression may be a potential biomarker for chemotherapeutic sensitivity and prognosis of breast cancer.

Down-regulated expression of AQP5 on lung in rat DIC model induced by LPS and its effect on the development of pulmonary edema.

Disseminated intravascular coagulation (DIC) is an acquired syndrome characterized by the widespread activation of coagulation, which leads to failure of multiple organs in the body. DIC of rat with lipopolysaccharide (LPS) is associated with subsequent pulmonary edema. Lung tissue is highly water permeable and expresses several aquaporins (AQPs). We therefore explored whether AQP5 involved in the pathogenesis of LPS-induced lung edema. The rats were intravenously infused with LPS (30 mg/kg) for 4 h, 6 h, 8 h, 10 h, and 12 h to induce DIC. Platelets count (PLT), D-Dimer (DD), fibrinogen (FIB), prothrombin time (PT), and activated partial thromboplastin time (APTT) were determined. Real-time quantitative PCR and Western blot were used to analyze the mRNA and protein expression of AQP5. Lung samples were stained with hematoxylin-eosin and lung wet/dry weight (W/D) ratios were measured. Here, we demonstrated that PLT and FIB values were significant decreased, the values for DD, PT, and APTT were marked increased, microthrombus was observed in lung specimens, and simultaneously with the AQP5 showed down-regulated expression following LPS infused from 4 h to 12 h. However, histopathological changes such as pulmonary edema and the increased lung W/D weight ratio were observed after LPS infused from 6 h to 12 h. These results indicated that the decreased expression of AQP5 maybe induce liquid transport obstacles between alveolar and capillary, and provides the report of AQP5 gene regulation, revealing the pathogenesis of pulmonary edema in DIC model of rat.

Crystal structures of E. coli laccase CueO at different copper concentrations.

CueO protein is a hypothetical bacterial laccase and a good laccase candidate for large scale industrial application. Four CueO crystal structures were determined at different copper concentrations. Low copper occupancy in apo-CueO and slow copper reconstitution process in CueO with exogenous copper were demonstrated. These observations well explain the copper dependence of CueO oxidase activity. Structural comparison between CueO and other three fungal laccase proteins indicates that Glu106 in CueO constitutes the primary counter-work for reconstitution of the trinuclear copper site. Mutation of Glu106 to a Phe enhanced CueO oxidation activity and supported this hypothesis. In addition, an extra alpha-helix from Leu351 to Gly378 covers substrate biding pocket of CueO and might compromises the electron transfer from substrate to type I copper.

[The treatment for complications of polyacrylamide hydrogel injection for augmentation mammaplasty by dual-plane breast augmentation].

OBJECTIVE: To search for the perfect therapy for the complications of breast augmentation by injecting polyacrylamide hydrogel. METHODS: 15 patients whose complications were severe after hydrogel injection were included in this study. Open suction and irrigation of cavity were performed in all patients and all received immediately dual-plane augmentation mammaplasty with silicon gel prostheses. RESULTS: 12 patient were followed up for 3 months to 1 year (mean 6.8 months) and no malposition or deformation occurred. 10 patients (20 breasts) had satisfactory results. The edges of the implant shell could be felt in 2 patients (3 breasts). 1 patient (1 breast) with breast firmness ranked Baker II . CONCLUSIONS: The dual-plane breast augmentation is a valuable technique to treat the complications of polyacrylamide hydrogel injection.