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OBJECTIVE@#To investigate the effect of Akt2 inhibitor on macrophage polarization in the periapical tissue in a rat model of periapical inflammation.@*METHODS@#Rat models of periapical inflammation were established in 28 normal SD rats by opening the pulp cavity of the mandibular first molars, followed by injection of normal saline and Akt2 inhibitor into the left and right medullary cavities, respectively. Four rats without any treatment served as the healthy control group. At 7, 14, 21 and 28 days after modeling, 7 rat models and 1 control rat were randomly selected for observation of inflammatory infiltration in the periapical tissues by X-ray and HE staining. Immunohistochemistry was used to detect the expression and localization of Akt2, macrophages and the inflammatory mediators. RT-PCR was performed to detect the mRNA expressions of Akt2, CD86, CD163, inflammatory mediators, miR-155-5p and C/EBPβ to analyze the changes in macrophage polarization.@*RESULTS@#X-ray and HE staining showed that periapical inflammation was the most obvious at 21 days after modeling in the rats. Immunohistochemistry and RT-PCR showed that compared with those in the control rats, the expressions of Akt2, CD86, CD163, miR-155-5p, C/EBPβ, and IL-10 increased significantly in the rat models at 21 days (P < 0.05). Compared with saline treatment, treatment with the Akt2 inhibitor significantly decreased the expression levels of Akt2, CD86, miR-155-5p and IL-6 and the ratio of CD86+M1/CD163+M2 macrophages (P < 0.05) and increased the expression levels of CD163, C/EBPβ and IL-10 in the rat models (P < 0.05).@*CONCLUSION@#Inhibition of Akt2 can delay the progression of periapical inflammation in rats and promote M2 macrophage polarization in the periapical inflammatory microenvironment possibly by reducing miR-155-5p expression and activating the expression of C/EBPβ in the Akt signaling pathway.
Subject(s)
Rats , Animals , Proto-Oncogene Proteins c-akt/metabolism , MicroRNAs/genetics , Interleukin-10 , Rats, Sprague-Dawley , Macrophages/metabolism , Inflammation/metabolismABSTRACT
Alzheimer's disease (AD) is the most common type of dementia. Almost two-thirds of patients with AD are female. The reason for the higher susceptibility to AD onset in women is unclear. However, hormone changes during the menopausal transition are known to be associated with AD. Most recently, we reported that follicle-stimulating hormone (FSH) promotes AD pathology and enhances cognitive dysfunctions via activating the CCAAT-enhancer-binding protein (C/EBPβ)/asparagine endopeptidase (AEP) pathway. This review summarizes our current understanding of the crucial role of the C/EBPβ/AEP pathway in driving AD pathogenesis by cleaving multiple critical AD players, including APP and Tau, explaining the roles and the mechanisms of FSH in increasing the susceptibility to AD in postmenopausal females. The FSH-C/EBPβ/AEP pathway may serve as a novel therapeutic target for the treatment of AD.
Subject(s)
Female , Humans , Male , Alzheimer Disease/pathology , CCAAT-Enhancer-Binding Protein-beta/metabolism , Cognitive Dysfunction/metabolism , Signal Transduction , Follicle Stimulating HormoneABSTRACT
Objective To detect the expression profile of transcription factor C/EBPβ in human immortalized normal hepatic cell lines and hepatocellular carcinoma cell lines so as to determine the correlation between C/EBP3 with cell death mediated by endoplasmic reticulum stress in hepatocellular cells.Methods We cultured the human immortalized normal hepatic cells lines HHL5 and HL7702 and hepatocellular carcinoma cell lines SMMC7721;Bel7402,HepG2 and Hep3B.Hep3B cells were used as the cell model in tunicamycin-induced endoplasmic reticulum stress.Cellular morphology was observed under an inverted optical microscope.MTT assay was used to assess the inhibition of cell growth.To detect cell apoptosis,the cells were dyed with Hoechst 33258 and observed using a fluorescence microscope.RToPCR and Western blotting were used to detect the expression of at mRNA and protein levels,respectively.Results We found that normally the mRNA and protein isoform of C/EBPβ,C/EBPβ-1,were both expressed in all of the four hepatocellular cell lines and the two immortalized normal hepatic cell lines,while C/EBPβ protein isoform C/EBPβ-3 was only expressed in the two immortalized normal hepatic cell lines.Tunicamycin increased the expressions of both mRNA and protein of C/EBPβ in Hep3B cells and the increase of protein isoform C/EBPβ-3 was the most remarkable.In Hep3B cells,cell death was induced by tunicamycin through endoplasmic reticulum stress activity.Apoptosis as well as paraptosis was observed in tunicamycin-induced cell death.Conclusion C/EBPβ-3,one of the protein isoforms of C/EBPβ,is only expressed in normal hepatic cell lines,but not in hepatocellular cell lines.C/EBPβ is involved in cell death mediated by endoplasmic reticulum stress activity in hepatocellular carcinoma cells.
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Objective To investigate the alteration of C/EBP α,C/EBP β and endoplasmic reticulum stress (ERS) related molecules (IRE1α and sXBP1) expression in pancreatic tissues in rats with hypertriglyceridemia related acute pancreatitis.Methods Ninety six Sprague Dawley (SD) rats were divided into 4 groups:control group,hypertriglyceridemia (HTG) group (n =24,fed with high fat diet for 2 weeks),AP group (n =24),HTG + AP group (n =24),and AP was induced by peritoneal injection of cerulein.The rats were sacrificed at 3,6,9,24 h after AP induction,respectively.The pathological changes of the pancreatic tissues were observed and scored by HE staining.Plasma levels of IL-1β,IL-6 and TNF-α were measured by ELISA.The expression of IRE1α,sXBP1,C/EBPoα,C/EBPβ mRNA were analyzed by real time PCR.The expressions of IRE1α,sXBP1,NF-kB,C/EBPα and C/EBPβ protein were determined by Western Blot.The expressions of C/EBPα and C/EBPβ proteins were also determined by immunohitochemistry.Results After two weeks of high fat diet,serum levels of triglyceride(TG) and total cholesterol (TC) in HTG group,HTG + AP group were much higher than those of the control group,and the difference was statistically significant (P ＜ 0.05).The pancreatic tissue injury was more severe in HTG + AP group,particularly at 9 h (P ＜ 0.05).And plasma IL-1β,IL-6 and TNF-α levels were also much higher in HTG + AP group when compared with that of AP group,the differences were all significant at 9 h (P=0.011;P=0.034;P =0.027).After AP induction,IRE1,sXBP1,C/EBP and C/EBPβ mRNA began to be up-regulated at 3 h,and IRE1 mRNA reached the highest level at 24 h,sXBP1 mRNA at 9 h,while C/EBP and C/EBPβ mRNA reached the highest level at 6 h.Compared with AP group,IRE1,sXBP1,C/EBP and C/EBPβ mRNA levels were much higher in HTG + AP group.In addition,as to IRE1 and sXBP1 mRNA,the difference was significant at 3,6,9,24 h,and C/EBP mRNA at 6,9,24 h,C/EBPβ mRNA at 6 and 9 h (P ＜ 0.05).After AP induction,IRE1α,sXBP1 and NF-kB proteins in the pancreatic tissue began to be up-regulated at 3 h,and all reached the highest level at 9 h.IRE1α,sXBP1 and NF-kB proteins were up-regulated more obviously in HTG + AP group,and the up-regulation in HTG + AP group was higher than that in AP group,and the high expressions of C/EBPα and C/EBPβ proteins could only be detected at 6 and 9 h in the HTG + AP group,while there was no expression detected in AP group.Conclusions C/EBPα,C/EBPβ,IRE1α and sXBP1 may be involved in the pathogenesis of HTG related AP,and IRE1α/sXBP1 pathway and C/EBPoα,C/EBPβ may mediate the pathologic injury and inflammation process of HTG related AP.
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The liver is unique in regenerative potential, which could recover the lost mass and function after injury from ischemia and resection. The underlying molecular mechanisms of liver regeneration have been extensively studied in the past using the partial hepatectomy (PH) model in rodents, where 2/3 PH is carried out by removing two lobes. The whole process of liver regeneration is complicated, orchestrated event involving a network of connected interactions, which still remain fully elusive. Bile acids (BAs) are ligands of farnesoid X receptor (FXR), a nuclear receptor of ligand-activated transcription factor. FXR has been shown to be highly involved in liver regeneration. BAs and FXR not only interact with each other but also regulate various downstream targets independently during liver regeneration. Moreover, recent findings suggest that tissue-specific FXR also contributes to liver regeneration significantly. These novel findings suggest that FXR has much broader role than regulating BA, cholesterol, lipid and glucose metabolism. Therefore, these researches highlight FXR as an important pharmaceutical target for potential use of FXR ligands to regulate liver regeneration in clinic. This review focuses on the roles of BAs and FXR in liver regeneration and the current underlying molecular mechanisms which contribute to liver regeneration.