NLRP3 inflammasome inhibitor MCC950 can reduce the damage of pancreatic and intestinal barrier function in mice with acute pancreatitis.

PURPOSE: Abnormal activation of NOD-like receptor protein 3 (NLRP3) inflammasome can lead to the occurrence and progression of acute pancreatitis. This study investigated the protective effect of MCC950 on pancreatitis mice. METHODS: Eighteen mice were randomly divided into control group, severe acute pancreatitis (SAP) group and SAP+MCC950 group. Serum interleukin (IL)-1ß, IL-6 and tumor necrosis factor-α (TNF-α) were measured by ELISA. Hematoxylin and eosin (HE) staining was used to evaluate the pathological damage. Western blotting was used to detect the expression of NLRP3 inflammasome and tight junction proteins in the small intestine and pancreas. RESULTS: MCC950 could reduce the levels of IL-6 and IL-1ß in SAP mice. After treatment with MCC950, the expression levels of NLRP3 inflammasome in the pancreas of SAP mice were significantly reduced and the pathological damage to the pancreas and intestine was alleviated. Compared with the control group, the expression of tight junction protein (ZO-1,occludin and claudin-4) in the intestinal mucosa of SAP mice was decreased, and the expression of claudin-4 and occludin were upregulated after MCC950 treatment. CONCLUSIONS: MCC950 can inhibit NLRP3 inflammasome activation and significantly reduce the inflammatory response and delay the process of pancreatitis. It has therapeutic potential in the treatment of acute pancreatitis.

NLRP3 inflammasome inhibitor MCC950 can reduce the damage of pancreatic and intestinal barrier function in mice with acute pancreatitis

Purpose: Abnormal activation of NOD-like receptor protein 3 (NLRP3) inflammasome can lead to the occurrence and progression of acute pancreatitis. This study investigated the protective effect of MCC950 on pancreatitis mice. Methods: Eighteen mice were randomly divided into control group, severe acute pancreatitis (SAP) group and SAP+MCC950 group. Serum interleukin (IL)-1ß, IL-6 and tumor necrosis factor-α (TNF-α) were measured by ELISA. Hematoxylin and eosin (HE) staining was used to evaluate the pathological damage. Western blotting was used to detect the expression of NLRP3 inflammasome and tight junction proteins in the small intestine and pancreas. Results: MCC950 could reduce the levels of IL-6 and IL-1ß in SAP mice. After treatment with MCC950, the expression levels of NLRP3 inflammasome in the pancreas of SAP mice were significantly reduced and the pathological damage to the pancreas and intestine was alleviated. Compared with the control group, the expression of tight junction protein (ZO-1,occludin and claudin-4) in the intestinal mucosa of SAP mice was decreased, and the expression of claudin-4 and occludin were upregulated after MCC950 treatment. Conclusions: MCC950 can inhibit NLRP3 inflammasome activation and significantly reduce the inflammatory response and delay the process of pancreatitis. It has therapeutic potential in the treatment of acute pancreatitis.

Nrp-1 Mediated Plasmatic Ago2 Binding miR-21a-3p Internalization: A Novel Mechanism for miR-21a-3p Accumulation in Renal Tubular Epithelial Cells during Sepsis.

The mechanism underlying sepsis-associated acute kidney injury (SAKI), which is an independent risk factor for sepsis-associated death, is unclear. A previous study indicates that during sepsis miR-21a-3p accumulates in renal tubular epithelial cells (TECs) as the mediator of inflammation and mediates TEC malfunction by manipulating its metabolism. However, the specific mechanism responsible for the accumulation of miR-21a-3p in TECs during sepsis is unrevealed. In this study, a cecal ligation and puncture- (CLP-) induced sepsis rat model and rat TEC line were used to elucidate the mechanism. Firstly, miR-21a-3p and Ago2 levels were found out to increase in both plasma and TECs during sepsis, and the increase of intracellular Ago2 and miR-21a-3p could be mitigated when Ago2 was either inactivated or downregulated in septic plasma. Moreover, membrane Nrp-1 expression of TECs was increased significantly during sepsis and Nrp-1 knockdown also mitigated the rise of both the intracellular Ago2 and miR-21a-3p levels in TECs incubated with septic plasma. Furthermore, it was revealed that Ago2 can be internalized by TECs mediated with Nrp-1 and this process had no effect on the intracellular content of miR-21a-3p. Both Ago2 and miR-21a-3p could bind to TECs derived Nrp-1 directly. Finally, it was determined that miR-21a-3p was internalized by TECs via Nrp-1 and Ago2 facilitated this process. Taken together, it can be concluded from our results that Ago2 binding miR-21a-3p from septic plasma can be actively internalized by TECs via Nrp-1 mediated cell internalization, and this mechanism is crucial for the rise of intracellular miR-21a-3p content of TECs during sepsis. These findings will improve our understanding of the mechanisms underlying SAKI and aid in developing novel therapeutic strategies.

CRBN knockdown mitigates lipopolysaccharide-induced acute lung injury by suppression of oxidative stress and endoplasmic reticulum (ER) stress associated NF-κB signaling.

Acute lung injury (ALI) is a common clinical disorder, resulting in substantial health problems in the world. However, the molecular mechanism that contributes to ALI is still unclear. Cereblon (CRBN) has recently been identified as a target for immunomodulatory drugs, playing a critical role in regulating various cellular processes. In the study, we attempted to explore the effects of CRBN on the progression of lipopolysaccharide (LPS)-induced ALI. First, we found that CRBN expression was markedly up-regulated in lung tissues of LPS-challenged mice. Our results suggested that CRBN knockdown mice exhibited better survival rate after LPS challenge, accompanied with improved histological alterations. Further, CRBN decrease effectively ameliorated pulmonary injury by reducing lung wet/dry (W/D) ratio and protein levels, neutrophil infiltration, myeloperoxidase (MPO) and lactate dehydrogenase (LDH) levels. In addition, LPS-triggered inflammation in lung tissues was markedly alleviated in CRBN knockdown mice by reducing the pro-inflammatory cytokines through the inactivation of nuclear factor-κB (NF-κB) signaling. Moreover, CRBN knockdown mice exhibited alleviated oxidative stress by promoting nuclear factor-erythroid 2 related factor 2 (Nrf-2)/heme oxygenase-1 (HO-1) signaling. ER stress stimulated by LPS in pulmonary tissues was significantly alleviated by CRBN knockdown through reducing the expression of ER stress associated signals, including CCAAT/Enhancer-Binding Protein Homologous Protein (CHOP), glucose-regulated protein 78 (GRP78), XBP-1, activating transcription factor (ATF)-4, ATF-6 and phosphorylated eukaryotic initiation factor 2 on Ser51 of the α subunit (eIF2α). The protective effects of CRBN knockdown against ALI were verified in LPS-incubated human pulmonary epithelial cells. Importantly, we found that CRBN knockdown-ameliorated inflammatory response was markedly abrogated by the pre-treatment of Nrf-2 inhibitor and ER stress activator, suggesting that CRBN-regulated inflammation in ALI was partly through the meditation of reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress. In conclusion, our study firstly provided a support that CRBN decrease effectively protected LPS-induced ALI against inflammatory response mainly through the repression of oxidative stress and ER stress.