Mechanism of dexmedetomidine protection against cisplatin induced acute kidney injury in rats.

OBJECTIVE: This study explored the molecular mechanisms by which dexmedetomidine (Dex) alleviates cisplatin (CP)-induced acute kidney injury (AKI) in rats. METHODS: CP-induced AKI models were established, and Dex was intraperitoneally injected at different concentrations into rats in the model groups. Subsequently, rats were assigned to the control, CP, CP + Dex 10 µg/kg, and CP + Dex 25 µg/kg groups. After weighing the kidneys of the rats, the kidney arterial resistive index was calculated, and CP-induced AKI was evaluated. In addition, four serum biochemical indices were measured: histopathological damage in rat kidneys was detected; levels of inflammatory factors, interleukin (IL)-1ß, IL-18, IL-6, and tumor necrosis factor alpha, in kidney tissue homogenate of rats were assessed through enzyme-linked immunosorbent assay (ELISA); and levels of NLRP-3, caspase-1, cleaved caspase-1, gasdermin D (GSDMD), and GSDMD-N in kidney tissues of rats were determined via western blotting. RESULTS: Dex treatment reduced nephromegaly and serum clinical marker upregulation caused by CP-induced AKI. In addition, hematoxylin and eosin staining revealed that Dex treatment relieved CP-induced kidney tissue injury in AKI rats. ELISA analyses demonstrated that Dex treatment reduced the upregulated levels of proinflammatory cytokines in the kidney tissue of AKI rats induced by CP, thereby alleviating kidney tissue injury. Western blotting indicated that Dex alleviated CP-induced AKI by inhibiting pyroptosis mediated by NLRP-3 and caspase-1. CONCLUSION: Dex protected rats from CP-induced AKI, and the mechanism may be related to NLRP-3/Caspase-1-mediated pyroptosis.

RGS5 augments astrocyte activation and facilitates neuroinflammation via TNF signaling.

Astrocytes contribute to chronic neuroinflammation in a variety of neurodegenerative diseases, including Parkinson's disease (PD), the most common movement disorder. However, the precise role of astrocytes in neuroinflammation remains incompletely understood. Herein, we show that regulator of G-protein signaling 5 (RGS5) promotes neurodegenerative process through augmenting astrocytic tumor necrosis factor receptor (TNFR) signaling. We found that selective ablation of Rgs5 in astrocytes caused an inhibition in the production of cytokines resulting in mitigated neuroinflammatory response and neuronal survival in animal models of PD, whereas overexpression of Rgs5 had the opposite effects. Mechanistically, RGS5 switched astrocytes from neuroprotective to pro-inflammatory property via binding to the receptor TNFR2. RGS5 also augmented TNFR signaling-mediated pro-inflammatory response by interacting with the receptor TNFR1. Moreover, interrupting RGS5/TNFR interaction by either RGS5 aa 1-108 or small molecular compounds feshurin and butein, suppressed astrocytic cytokine production. We showed that the transcription of astrocytic RGS5 was controlled by transcription factor early B cell factor 1 whose expression was reciprocally influenced by RGS5-modulated TNF signaling. Thus, our study indicates that beyond its traditional role in G-protein coupled receptor signaling, astrocytic RGS5 is a key modulator of TNF signaling circuit with resultant activation of astrocytes thereby contributing to chronic neuroinflammation. Blockade of the astrocytic RGS5/TNFR interaction is a potential therapeutic strategy for neuroinflammation-associated neurodegenerative diseases.

Expressions and clinical significance of autophagy-related markers Beclin1, LC3, and EGFR in human cervical squamous cell carcinoma.

PURPOSE: We aimed to investigate the expression of EGFR and the autophagy-related markers Beclin1 and LC3 in cervical cancer. METHODS: Beclin1, LC3, and EGFR expression were analyzed in 80 samples of cervical squamous cell carcinoma (SCC), 40 samples of high-grade cervical intraepithelial neoplasia (CIN), and 40 samples of normal cervical tissues by immunohistochemistry. The protein expression rates were analyzed with χ (2) and Fisher's exact tests. Differences in overall survival (OS) were determined using the Kaplan-Meier method and log-rank tests. RESULTS: Cervical cancer, high-grade CIN, and normal cervical epithelial cells expressed Beclin1 in 26.2%, 77.5%, and 82.5% of patients, respectively, and expressed LC3 in 28.8%, 70.0%, and 75.0% of patients, respectively. There was a significant difference between cervical SCC and high-grade CIN or normal cervical epithelial cells (P=0.000). Cervical cancer cells, high-grade CIN cells, and normal cervical epithelial cells expressed EGFR in 68.8%, 62.5%, and 12.5% of patients, respectively. There was a significant difference between cervical SCC or high-grade CIN and normal cervical epithelial cells (P=0.000). No significant association between Beclin1 or LC3 or EGFR expression and various clinicopathological parameters was observed in cervical SCC. There was no significant correlation between Beclin1, LC3, EGFR expression, and 5-year OS rates of cervical SCC patients. Beclin1- or LC3-negativity with EGFR-positivity in cervical SCC was associated with a higher Federation International of Gynecology and Obstetrics (FIGO) stage (P=0.011 and P=0.013, respectively) and pelvic lymph node metastasis (P=0.036 and P=0.092, respectively). The 5-year OS rates did not significantly differ between Beclin1- or LC3-positive and -negative patients with positive EGFR. CONCLUSION: Autophagy was downregulated and EGFR was upregulated in cervical SCC. Autophagy downregulation combined with EGFR upregulation promotes the progression of cervical SCC.

EGFR inhibitors and autophagy in cancer treatment.

Epidermal growth factor receptor (EGFR) inhibitor treatment is a strategy for cancer therapy. However, innate and acquired resistance is a major obstacle of the efficacy. Autophagy is a self-digesting process in cells, which is considered to be associated with anti-cancer drug resistance. The activation of EGFR can regulate autophagy through multiple signal pathways. EGFR inhibitors can induce autophagy, but the specific function of the induction of autophagy by EGFR inhibitors remains biphasic. On the one hand, autophagy induced by EGFR inhibitors acts as a cytoprotective response in cancer cells, and autophagy inhibitors can enhance the cytotoxic effects of EGFR inhibitors. On the other hand, a high level of autophagy after treatment of EGFR inhibitors can also result in autophagic cell death lacking features of apoptosis, and the combination of EGFR inhibitors with an autophagy inducer might be beneficial. Thus, autophagy regulation represents a promising approach for improving the efficacy of EGFR inhibitors in the treatment of cancer patients.

High prevalence of reflux esophagitis among upper endoscopies in Chinese patients with chronic liver diseases.

BACKGROUND: Reflux esophagitis (RE) is increasing in prevalence in China. There are very few studies on the prevalence and factors related to RE in patients with chronic liver diseases. The aims of this study were to determine the prevalence of RE by endoscopy in patients with chronic liver diseases and the possible related predictors of RE. METHODS: A total of 1,280 patients with chronic liver disease and 29 patients with acute hepatitis A or E were prospectively evaluated. There were 879 and 401 patients with liver cirrhosis or chronic hepatitis, respectively. RE was classified by endoscopy according to the Los Angeles classification scheme. RESULTS: RE was diagnosed in 36.4% (469/1280) of the chronic liver disease patients, which was significantly higher than in the acute hepatitis patients (10.3% [3/29], P < 0.001). RE accounted for 43.0%, 9.7%, and 60.2% of patients with liver cirrhosis, chronic hepatitis(mild and medium), and liver failure, respectively. A high prevalence of RE existed in patients with liver failure and/or Child B and C liver cirrhosis, with typical symptoms of RE in 21.3% of the patients (100/469). There was a significant relationship between gender, age, ascites, and RE. CONCLUSIONS: The high prevalence of RE among upper endoscopies of patients with severe chronic liver disease was demonstrated. Asymptomatic RE was more common in cirrhotic and liver failure patients. The role of RE in variceal bleeding, however, needs to be demonstrated.