Shaoli Zhou

MiR-216b is involved in pathogenesis and progression of hepatocellular carcinoma through HBx-miR-216b-IGF2BP2 signaling pathway

This study aims to investigate the expression status of miRNA-216b in familial hepatocellular carcinoma (HCC) and the correlation between miRNA-216b expression and pathogenesis, as well as the progression of HCC. The expression profile of miRNAs in plasma of peripheral blood between HCC patients with HCC family history and healthy volunteers without HCC family history was determined by microarray. Using real-time quantitative PCR to detect the expression in paired tissues from 150 patients with HCC, miR-216b was selected as its expression value in HCC patients was significantly lower compared with healthy volunteers. Next, miR-216b expression and the clinicopathological features of HCC were evaluated. The effect of miR-216b expression on tumor cells was investigated by regulating miR-216b expression in SMMC-7721 and HepG2 in vitro and in vivo. Finally, we explored mRNA targets of miR-216b. In 150 HCC, 37 (75%) tumors showed reduced miR-216b expression comparing with their adjacent liver tissues. The decreased expression of miR-216b was significantly correlated with tumor volume (P=0.044), HBV infection (P=0.026), HBV DNA quantitative (P=0.001) and vascular invasion (P=0.032). The 5-year disease-free survival and overall rates after liver resection in low expression and high expression groups of miR-216b are 62% and 54%, 25% and 20%, respectively. MiR-216b overexpression inhibited cell proliferation, migration and invasion, and miR-216b inhibition did the opposite. The expression of hepatitis B virus x protein (HBx) has tight correlation with downregulation of miR-216b. Furthermore, miR-216b downregulated the expression of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) and exerted its tumor-suppressor function through inhibition of protein kinase B and extracellular signal-regulated kinase signaling downstream of IGF2. MiR-216b inhibits cell proliferation, migration and invasion of HCC by regulating IGF2BP2 and it is regulated by HBx.

Propofol prevents lung injury after intestinal ischemia–reperfusion by inhibiting the interaction between mast cell activation and oxidative stress

AIMS Both mast cells and oxidative stress are involved in acute lung injury (ALI) induced by intestinal ischemia-reperfusion (IIR). The aim of this study was to investigate whether propofol could improve IIR-induced ALI through inhibiting their interaction. MAIN METHODS Repetitive, brief IIR or IIR+compound 48/80 was performed in adult Sprague-Dawley rats pretreated with saline, apocynin or propofol. And their lungs were excised for histology, ELISA and protein-expression measurements 2h after reperfusion. KEY FINDINGS Rats pretreated with saline developed critical ALI 2h after IIR. We found significant elevations in lung injury scores, lung wet/dry ratio and gp91phox, p47phox, intercellular cell adhesion molecule-1 protein expressions and higher level of malondialdehyde, interleukin-6 contents, and myeloperoxidase activities, as well as significant reductions in superoxide dismutase activities, accompanied with increases in mast cell degranulation evidenced by significant increases in mast cell counts, β-hexosaminidase concentrations, and tryptase expression. And the lung injury was aggravated in the presence of compound 48/80. However, pretreated with propofol and apocynin not only ameliorated the IIR-mediated pulmonary changes beyond the biochemical changes but also reversed the changes that were aggravated by compound 48/80. SIGNIFICANCE Propofol protects against IIR-mediated ALI, most likely by inhibiting the interaction between oxidative stress and mast cell degranulation.

Dexmedetomidine protects against apoptosis induced by hypoxia/reoxygenation through the inhibition of gap junctions in NRK-52E cells

AIMS The α2-adrenoceptor inducer dexmedetomidine (Dex) provides renoprotection against ischemia/reperfusion (I/R) injury, but the mechanism of this effect is largely unknown. The present study investigated the effect of Dex on apoptosis induced by hypoxia/reoxygenation (H/R) and the relationship between this effect and gap junction intercellular communication (GJIC). MAIN METHODS In vitro, two cell lines of normal rat kidney proximal tubular cells (NRK-52E) and HeLa cells that were transfected with a connexin 32 (Cx32) plasmid were exposed to H/R. The role of Dex in the modulation of H/R-induced apoptosis was explored by the manipulation of connexin expression, and hence gap junction (GJ) function, using a GJIC inhibitor, heptanol, and a GJIC inducer, retinoic acid. GJ function and the Cx32 protein level were determined by the parachute dye-coupling assay and Western blotting, respectively. KEY FINDINGS Dex and heptanol significantly reduced H/R-induced apoptosis in NRK-52E cells. The anti-apoptosis effect of Dex was exhibited only in Cx32-expressing HeLa cells. One hour Dex exposure inhibited GJ function mainly via a decrease in Cx32 protein levels in NRK-52E cells. SIGNIFICANCE Our data suggest that Dex reduced H/R-induced apoptosis through the inhibition of GJ activity by reducing Cx32 protein levels.

Dexmedetomidine Protects Rat Liver against Ischemia-Reperfusion Injury Partly by the α2A-Adrenoceptor Subtype and the Mechanism Is Associated with the TLR4/NF-κB Pathway

Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling plays a dominant role in the pathogenesis of liver ischemia-reperfusion (IR) injury. Dexmedetomidine (Dex) protects the liver against IR injury via α2-adrenoceptor activation, but the contribution of TLR4 signaling remains unknown. The authors aimed to examine whether pretreatment with Dex produces hepatic protection and investigate the influence of Dex on TLR4/NF-κB signaling. Dex was given via intraperitoneal injection 30 min prior to orthotopic autologous liver transplantation (OALT) in rats, and three α2-adrenoceptor antagonists including atipamezole (a nonselective α2 receptor blocker), ARC-239 (a specific α2B/C blocker) and BRL-44408 (a specific α2A blocker) were injected intraperitoneally 10 min before Dex administration. Histopathologic evaluation of the liver and the measurement of serum alanine aminotransferase activity, TLR4/NF-κB expression in the liver, and pro-inflammatory factors (serum tumor necrosis factor-α, interleukin-1β and hepatic myeloperoxidase) concentrations were performed 8 h after OALT. Dex ameliorated liver injury after OALT probably by suppressing the TLR4/NF-κB pathway and decreasing inflammatory mediator levels. The protective effects of Dex were reversed by atipamezole and BRL-44408, but not by ARC-239, suggesting that these effects were mediated in part by the α2A subtype. In conclusion, Dex attenuates liver injury partly via the α2A-adrenoceptor subtype, and the mechanism is due to the suppression of the TLR4/NF-κB pathway.

Brg1-mediated Nrf2/HO-1 pathway activation alleviates hepatic ischemia-reperfusion injury

Cytoprotective gene heme oxygenase 1 (HO-1) could be induced by nuclear factor E2-related factor 2 (Nrf2) nuclear translocation. The purpose of this study was to determine the role of Brahma-related gene 1 (Brg1), a catalytic subunit of SWI2/SNF2-like chromatin remodeling complexes, in Nrf2/HO-1 pathway activation during hepatic ischemia–reperfusion (HIR). Our results showed that hepatic Brg1 was inhibited during early HIR while Brg1 overexpression reduced oxidative injury in CMV-Brg1 mice subjected to HIR. Moreover, promoter-driven luciferase assay showed that overexpression of Brg1 by adenovirus transfection in AML12 cells selectively enhanced HO-1 gene expression after hypoxia/reoxygenation (H/R) treatment but did not affect the other Nrf2 target gene NQO1. Furthermore, inhibition of HO-1 by the selective HO-1 inhibitor zinc protoporphyria could partly reverse the hepatic protective effects of Brg1 overexpression while HO-1-Adv attenuated AML12 cells H/R damage. Further, chromatin immunoprecipitation analysis revealed that Brg1 overexpression, which could significantly increase the recruitment of Brg1 protein to HO-1 but not NQO1 promoter, was recruited by Nrf2 to the HO-1 regulatory regions in AML12 hepatocytes subjected to H/R. In conclusion, our results demonstrated that restoration of Brg1 during reperfusion could enhance Nrf2-mediated inducible expression of HO-1 during HIR to effectively increase antioxidant ability to combat against hepatocytes damage.

Histamine at low concentrations aggravates rat liver BRL-3A cell injury induced by hypoxia/reoxygenation through histamine H2 receptor in vitro.

AIM Histamine released from mast cell degranulation participates in the pathogenesis of ischemia/reperfusion injury. The purpose of our study was to define the role of histamine in hypoxia/reoxygenation mediated liver cell injury and to elucidate the underlying mechanism in vitro. METHODS Histamine alone or in combination with H1 receptor antagonist (pyrilamine), H2 receptor antagonist (cimetidine) or H3/4 receptor antagonist (thioperamide) at different concentrations before hypoxia was added to rat liver BRL-3A cell which was subjected to 24h hypoxia followed by 4h reoxygenation. Cell proliferation, apoptosis and the changes of ultrastructure were assessed, and MDA contents, SOD activities and ALT levels were quantified as well. RESULTS Histamine (from 10(-3) to 10(-9) M) did not affect the growth of BRL-3A cells without hypoxia treatment. However, histamine 10(-8)M significantly lowered the growth of BRL-3A cells challenged by hypoxia/reoxygenation, accompanied with concomitant elevations in MDA contents and decreases in SOD activities, all these changes were blocked by cimetidine, not by pyrilamine or thioperamide. However, histamine (above 10(-6) M) did not show exacerbating effects in BRL-3A cell subjected to hypoxia/reoxygenation. CONCLUSION Histamine at low concentrations (10(-7)-10(-9) M) aggravates hypoxia/reoxygenation mediated BRL-3A damage through histamine H2 receptor.

Dexmedetomidine improves gastrointestinal motility after laparoscopic resection of colorectal cancer: A randomized clinical trial.

Background:To investigate the effects of intraoperative application of dexmedetomidine (Dex) on early gastrointestinal motility after laparoscopic resection of colorectal cancer. Methods:In this prospective, randomized double-blind investigation, 60 patients who underwent laparoscopic resection of colorectal cancer were randomly allocated to receive Dex (DEX group, n = 30) or saline (CON group, n = 30). In the DEX group, Dex was loaded (1 &mgr;g/kg) before anesthesia induction and was infused (0.3 &mgr;g/kg/h) during surgery. Time to postoperative first flatus (FFL) and first feces (FFE), and time to regular diet were recorded. Serum diamine oxidase (DAO) activity and intestinal fatty acid-binding protein (I-FABP) were detected. Results:Both the time to the FFL (44.41 ± 4.51 hours vs 61.03 ± 5.16 hours, P = 0.02) and the time to the FFE (60.67 ± 4.94 hours vs 82.50 ± 6.88 hours, P = 0.014) were significantly shorter in the DEX group than the CON group. Furthermore, the time to regular diet of the DEX group was shorter than that of the CON group (76.15 ± 4.11 hours vs 91.50 ± 5.70 hours, P = 0.037). Both DAO and I-FABP increased significantly from beginning of surgery to postoperative day 1 in the CON group (2.49 ± 0.41 ng/mL vs 4.48 ± 0.94 ng/mL for DAO, P = 0.028, 1.32 ± 0.09 ng/mL vs 2.17 ± 0.12 ng/mL for I-FABP, P = 0.045, respectively), whereas no significant change was observed in the DEX group. Furthermore, patients in the DEX group had stable hemodynamics and shorter hospital stay than those in the CON group. Conclusion:Dex administration intraoperatively benefits recovery of gastrointestinal motility function after laparoscopic resection of colorectal cancer with stable hemodynamics during surgery though further studies are needed to explore the mechanisms of Dex on gastrointestinal motility.

Propofol pretreatment attenuates remote kidney injury induced by orthotopic liver autotransplantation, which is correlated with the activation of Nrf2 in rats

Nuclear factor erythroid 2‑related factor 2 (Nrf2) is a critical regulator of the cellular‑defense response in protection against oxidative injury. Several studies have demonstrated that propofol ameliorates ischemia/reperfusion injury in a number of organs. However, whether propofol exerts renal protection against liver transplantation via Nrf2 activation remains to be elucidated. The aim of the present study was to investigate the effects of orthotopic liver autotransplantation (OLAT) on renal Nrf2 expression and to determine whether propofol protects against kidney injury induced by OLAT via Nrf2 activation. A total of 24 male Sprague Dawley rats were randomly divided into four groups: sham surgery + normal saline (sham group); OLAT + normal saline (OLAT group); OLAT + propofol 50 mg/kg (L‑Prop group) and OLAT + propofol 100 mg/kg (H‑Prop group). Normal saline and propofol were administered for 3 consecutive days through an intraperitoneal injection prior to surgery. Kidney pathology, blood urea nitrogen (BUN), creatinine (Cr), superoxide anion (O2•‑), hydroxyl radical (·OH), maleic dialdehyde (MDA) and expression levels of Nrf2, Kelch‑like ECH‑associated protein 1 (Keap1), heme oxygenase‑1 (HO‑1) and NADP quinine oxidoreductase 1 (NQO1) were assessed 8 h after OLAT. It was demonstrated that OLAT induced remote kidney damage. Pretreatment with propofol significantly ameliorated renal pathology and abrogated the increase of the Cr and BUN concentrations, O2•‑ and ·OH activities, and MDA levels induced by OLAT. In the H‑Prop group, Keap1 expression in the cytoplasm was decreased and Nrf2 expression in the nucleus was upregulated, accompanied by an increase of HO‑1 and NQO1 expression. The present results suggest that propofol pretreatment exerted renal protection against OLAT, with the upregulation of nuclear Nrf2 expression as a potential mechanism.

Asymmetric dimethylarginine and all-cause mortality: a systematic review and meta-analysis

Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), impairs the beneficial effect of NO. The predictive value of ADMA for all-cause mortality remains controversial, though it is important in the development of cardiovascular disease (CVD) and progression to dialysis in renal disease. This systematic review and meta-analysis was conducted to investigate the association between circulating ADMA and all-cause mortality. Studies with data pertinent to the association between circulating ADMA and all-cause mortality were reviewed and OR, HR or RR with 95% CI derived from multivariate Cox’s proportional-hazards analysis were extracted. A total of 34 studies reporting 39137 participants were included in final analysis. The results demonstrated that circulating ADMA was independently associated with all-cause mortality (RR = 1.27, 95% CI: 1.20–1.34). The association was still statistically significant in patients with pre-existing renal disease (RR = 1.30, 95% CI: 1.19–1.43) and pre-existing CVD (RR = 1.26, 95% CI: 1.16–1.37). In those without pre-existing renal or CVD, ADMA also predicted all-cause mortality (RR = 1.31, 95% CI: 1.13–1.53). The present study suggests a positive association of circulating ADMA with all-cause mortality. Further studies are needed to investigate the effects of interventions on ADMA, and the value of ADMA as a biomarker.

Overexpression of Brg1 Alleviates Hepatic Ischemia/Reperfusion-Induced Acute Lung Injury through Antioxidative Stress Effects

Aim To investigate whether overexpression of Brahma-related gene-1 (Brg1) can alleviate lung injury induced by hepatic ischemia/reperfusion (HIR) and its precise mechanism. Methods Cytomegalovirus-transgenic Brg1-overexpressing (CMV-Brg1) mice and wild-type (WT) C57BL/6 mice underwent HIR. Lung histology, oxidative injury markers, and antioxidant enzyme concentrations in the lung were assessed. The protein expression levels of Brg1, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H:quinone oxidoreductase 1 (NQO1) in the lung were analyzed by Western blotting. Results In the WT group, histopathological analysis revealed that lung damage peaked at 6 h after HIR. Meanwhile, the lung reactive oxygen species (ROS) and 8-isoprostane levels were significantly increased. The protein expression of Brg1 in lung tissue decreased to a minimum at 6 h. Overexpression of Brg1 alleviated lung injury and decreased the amounts of oxidative products, including the levels of 8-isoprostane and ROS, as well as the percentage of positive cells for 4-hydroxynonenal (4-HNE) and 8-oxo-2′-deoxyguanosine (8-OHdG). Brg1 overexpression increased the expression and nuclear translocation of Nrf2 as well as activated the antioxidases. In addition, it decreased the expression of inflammatory factors. Conclusion Overexpression of Brg1 alleviates oxidative lung injury induced by HIR, likely through the Nrf2 pathway.