Lipopolysaccharide induced synthesis of CD14 proteins and its gene expression in hepatocytes during endotoxemia

Butyrate Regulates Intestinal DNA Virome and Lipopolysaccharide Levels to Prevent High-Fat Diet-Related Liver Damage in Rats

As the adsorption receptor of bacteriophage tail protein, bacterial lipopolysaccharide (LPS) is a main culprit responsible for nonalcoholic fatty liver disease (NAFLD) caused by high-fat diets. However, few studies have focused on how the interaction between intestinal bacteriophages and bacterial LPS affects the development and progression of NAFLD. Herein, we determined that excessive fat intake significantly increases the levels of endogenous LPS, while the administration of beneficial metabolites of the intestinal microbiota (specifically butyrate) alleviated hepatic injury in rats. The beneficial mechanism of butyrate was attributed to the reprogramming of the structure of the intestinal DNA virome (primarily, phageome). Butyrate possesses the potential to augment bacteriophagic microbial diversity, thereby potentially facilitating interactions between intestinal bacteriophages and bacterial LPS (in the case of homologous phage), further improving mitochondrial dysfunction and reactive oxygen species production, which, in turn, lowered HepG2 cell damage. Likewise, fecal phage transplantation further confirmed that intestinal phages from rats that received butyrate could effectively interact with bacterial LPS to reduce liver damage in rats. Taken together, modifying the intestinal phageome is a promising treatment option for high-fat diet-related NAFLD.

Presepsin As a Biomarker for Evaluating Prognosis and Early Innate Immune Response of Out-of-Hospital Cardiac Arrest Patients After Return of Spontaneous Circulation

OBJECTIVES

After return of spontaneous circulation, patients who experienced out-of-hospital cardiac arrest present an impaired innate immune response that resembles sepsis. Presepsin, a new biomarker for sepsis, has not been studied in out-of-hospital cardiac arrest patients. This study explored the role of presepsin in evaluating the prognosis and early innate immune alteration of out-of-hospital cardiac arrest patients after return of spontaneous circulation by observing presepsin levels, CD14, and human leukocyte antigen-DR expression on monocytes.

DESIGN

Retrospective analysis.

SETTING

The emergency department of an urban university tertiary hospital.

PARTICIPANTS

One hundred sixty-five out-of-hospital cardiac arrest patients with return of spontaneous circulation more than 12 hours, and 100 healthy individuals.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma presepsin and procalcitonin levels were tested after resuscitation (day 0) and on days 1 and 3 after return of spontaneous circulation. Presepsin levels were higher in out-of-hospital cardiac arrest patients than in healthy individuals. In the first 3 days, presepsin and procalcitonin levels were persistently lower in 28-day survivors and patients with favorable neurologic outcome patients than in 28-day nonsurvivors and patients with unfavorable neurologic outcome. On days 0, 1, and 3, different cut-off values of presepsin showed prognostic value for 28-day mortality and favorable neurologic outcomes similar to procalcitonin. CD14 and human leukocyte antigen-DR expression on monocytes were analyzed by flow cytometry. Compared with controls, CD14 expression in out-of-hospital cardiac arrest patients increased on day 1 and began to decrease on day 3, whereas human leukocyte antigen-DR+ monocyte percentages decreased on days 1 and 3. Presepsin and procalcitonin had a low positive correlation with CD14 expression and a strong negative correlation with human leukocyte antigen-DR+ monocyte percentages on day 1.

CONCLUSIONS

Plasma presepsin concentrations are independent prognostic factors for out-of-hospital cardiac arrest patients after return of spontaneous circulation and are correlated with abnormal CD14 and human leukocyte antigen-DR expression on monocytes. Monitoring presepsin levels may be helpful for evaluating the prognosis and impaired innate immune response in the early period after return of spontaneous circulation.

Anti-inflammatory role of naringenin in rats with ethanol induced liver injury

The aim of the study was to investigate the antiinflammatory effects of naringenin in rats induced liver damage by exposure to ethanol. Rats were divided into four groups, groups 1 and 2 received isocaloric glucose; groups 3 and 4 received 20% ethanol equivalent to 6 g/kg body weight everyday for the total experimental period of 60 days. In addition, groups 2 and 4 were supplemented with naringenin (50 mg/kg p.o.) everyday for the last 30 days of the experiment. The results showed significantly elevated levels/activities/expression of serum aspartate and alanine transaminases, iron, ferritin, transforming growth factor-alpha (TNF-α), interleukin-6 (IL-6), nuclear factor-kappa B (NF-κB), cyclooxygenase-2 (COX-2), macrophage inflammatory protein 2 (MIP-2) and CD14 in ethanol fed rats as compared to those of the control. Ethanol-fed rats exhibited increased staining for the presence of inducible nitric oxide (iNOS) protein adducts in the liver. Supplementation with naringenin for the last 30 days to ethanol-fed rats, significantly decreased the levels/activities/expression of serum aspartate and alanine transaminases, iron, ferritin, TNF-α, IL-6, NF-κB, COX-2, MIP-2, CD14 and iNOS protein adducts in the liver as compared to the untreated ethanol fed rats. The inhibition of TNF-α, IL-6, NF-κB, COX-2, MIP-2, iNOS and CD14 by naringenin may contribute to its antiinflammatory activity in ethanol fed rats.

Endotoxin and CD14 in the progression of biliary atresia

Background

Biliary atresia (BA) is a typical cholestatic neonatal disease, characterized by obliteration of intra- and/or extra-hepatic bile ducts. However, the mechanisms contributing to the pathogenesis of BA remain uncertain. Because of decreased bile flow, infectious complications and damaging endotoxemia occur frequently in patients with BA. The aim of this study was to investigate endotoxin levels in patients with BA and the relation of these levels with the expression of the endotoxin receptor, CD14.

Methods

The plasma levels of endotoxin and soluble CD14 were measured with a pyrochrome Limulus amebocyte lysate assay and enzyme-linked immunosorbent assay in patients with early-stage BA when they received the Kasai procedure (KP), in patients who were jaundice-free post-KP and followed-up at the outpatient department, in patients with late-stage BA when they received liver transplantation, and in patients with choledochal cysts. The correlation of CD14 expression with endotoxin levels in rats following common bile duct ligation was investigated.

Results

The results demonstrated a significantly higher hepatic CD14 mRNA and soluble CD14 plasma levels in patients with early-stage BA relative to those with late-stage BA. However, plasma endotoxin levels were significantly higher in both the early and late stages of BA relative to controls. In rat model, the results demonstrated that both endotoxin and CD14 levels were significantly increased in liver tissues of rats following bile duct ligation.

Conclusions

The significant increase in plasma endotoxin and soluble CD14 levels during BA implies a possible involvement of endotoxin stimulated CD14 production by hepatocytes in the early stage of BA for removal of endotoxin; whereas, endotoxin signaling likely induced liver injury and impaired soluble CD14 synthesis in the late stages of BA.

Coexpression of CD14 and CD326 discriminate hepatic precursors in the human fetal liver

The molecular and cellular profile of liver cells during early human development is incomplete, complicating the isolation and study of hepatocytes, cholangiocytes, and hepatic stem cells from the complex amalgam of hepatic and hematopoietic cells, that is, the fetal liver. Epithelial cell adhesion molecule, CD326, has emerged as a marker of hepatic stem cells, and lipopolysaccharide receptor CD14 is known to be expressed on adult hepatocytes. Using flow cytometry, we studied the breadth of CD326 and CD14 expression in midgestation liver. Both CD45(+) hematopoietic and CD45(-) nonhematopoietic cells expressed CD326. Moreover, diverse cell types expressing CD326 were revealed among CD45(-) cells by costaining for CD14. Fluorescence-activated cell sorting was used to isolate nonhematopoietic cells distinguished by expression of high levels of CD326 and low CD14 (CD326(++)CD14(lo)), which were characterized for gene expression associated with liver development. CD326(++)CD14(lo) cells expressed the genes albumin, α-fetoprotein, hepatic nuclear factor 3α, prospero-related homeobox 1, cytochrome P450 3A7, α(1)-antitrypsin, and transferrin. Proteins expressed included cell-surface CD24, CD26, CD29, CD34, CD49f, CD243, and CD324 and, in the cytoplasm, cytokeratins-7/8 (CAM 5.2 antigen) and some cytokeratin-19. Cultured CD326(++)CD14(lo) cells yielded albumin(+) hepatocytes, cytokeratin-19(+) cholangiocytes, and hepatoblasts expressing both markers. Using epifluorescence microscopy we observed CD326 and CD14 expression on fetal hepatocytes comprising the liver parenchyma, as well as on cells associated with ductal plates and surrounding large vessels. These findings indicate that expression of CD14 and CD326 can be used to identify functionally distinct subsets of fetal liver cells, including CD326(++)CD14(lo) cells, representing a mixture of parenchymal cells, cholangiocytes, and hepatoblasts.

Human hepatocytes secrete soluble CD14, a process not directly influenced by HBV and HCV infection

BACKGROUND

Chronic hepatitis B (HBV) and hepatitis C (HCV) patients have elevated plasma levels of soluble CD14 (sCD14). We examined whether human hepatocytes produce sCD14 in vivo, and whether HBV or HCV infections influence this chimeric production.

METHODS

uPA-SCID mice were transplanted with primary human hepatocytes and some animals were subsequently infected with HBV or HCV. Plasma from these mice was analyzed for the presence of human sCD14. The liver was examined via immunohistochemistry.

RESULTS

A soluble form of human CD14 could be detected in the plasma from successfully transplanted mice, while it was completely absent in non-transplanted control animals. The isoform of this human sCD14 corresponded with the most abundant isoform found in human plasma. CD14 levels in circulation were not significantly different between non-infected, HBV infected and HCV infected animals.

CONCLUSIONS

Our data indicate that human hepatocytes produce sCD14 in vivo, and that liver cells might be the major source of sCD14 in normal human plasma. In addition we demonstrate that HBV and HCV infections have no direct influence on the production of sCD14 by human hepatocytes in this chimeric model.

Normal rat hepatic stellate cells respond to endotoxin in LBP-independent manner to produce inhibitor(s) of DNA synthesis in hepatocytes

Endotoxin is implicated in the pathology of acute liver failure. The mechanisms of its actions on quiescent hepatic stellate cells (qHSCs) and their implications in hepatocyte injury are incompletely understood. We investigated effects of endotoxin (bacterial lipopolysaccharide; LPS) on qHSCs and subsequently on hepatocytes. After overnight culture following their isolation, qHSCs were incubated with or without endotoxin for 24 h. The cells and the culture supernatant were analyzed for cytokines and nitric oxide (NO) synthesis. The effects of qHSC-conditioned media on hepatocytes were then determined. LPS increased inducible NO synthase expression, stimulated NO synthesis, and inhibited DNA synthesis in qHSCs. qHSC-conditioned medium inhibited DNA synthesis in hepatocytes without affecting NO synthesis, while LPS (1-1,000 ng/ml)-conditioned qHSC medium stimulated NO synthesis and caused further inhibition of DNA synthesis and apoptosis. These effects of LPS were more pronounced when qHSCs were incubated with serum, but not with LPS-binding protein (LBP) although CD14 (a receptor for LPS-LBP complex) was found in qHSCs. LPS stimulated the synthesis of TNF-alpha, interleukin (IL)-6, and IL-1beta but not of TGF-beta in qHSCs. Individually or together, L-N(G)-monomethylarginine and antibodies to IL-1beta, IL-6, and TNF-alpha only partly reversed qHSC + LPS-conditioned medium-induced inhibition of DNA synthesis in hepatocytes. These results suggest that the effects of LPS on qHSCs are novel, occurring without the aid of LBP/CD14. They also indicate that other factors, in addition to NO, TGF-beta, TNF-alpha, IL-1beta, and IL-6 are involved in the mechanisms of the growth inhibitory effects of qHSCs on hepatocytes.

CD14-dependent alterations in c-Jun expression in the liver after burn injury

BACKGROUND

Burn injury-triggered activation of lipopolysaccharide signaling via the CD14 pathway alters the expression of a variety of downstream genes contributing to pathogenic changes in distant organs. The regulation of CD14 and its role in the immediate-early response of c-Jun in the liver after burn injury were investigated in this study.

MATERIALS AND METHODS

An incidental identification of the differential induction of CD14 mRNA after an approximately 18% TBSA burn injury in mice was confirmed by RT-PCR and immunohistochemical analyses of CD14 expression. Subsequently, CD14's role in the immediate-early regulation of c-Jun expression in the liver after injury was examined by Western blot analysis using CD14 knockout (KO) mice.

RESULTS

RT-PCR analysis demonstrated a rapid and transient induction of CD14 mRNA in the liver and lungs of mice after injury. Immunohistochemical analysis revealed a peak induction of CD14 reactivity in cells appearing to be Kupffer cells at day 1 after injury. Furthermore, an augmented and delayed induction of c-Jun mRNA was observed in the liver of CD14 KO mice after injury compared to wild-type controls. The induction of phosphorylated (serine 63 or serine 73) forms of c-Jun after injury was lower in the livers of CD14 KO mice than that in WT controls.

CONCLUSIONS

This study provides evidence that injury elicits CD14 induction as well as hyperphosphorylation of the c-Jun N-terminus activation domain and that CD14 is involved in the modulation of c-Jun's transactivation potential via phosphorylation, which may be associated with hepatic pathogenesis after injury.

Cloning of human 15ku selenoprotein gene from H9 T cells

AIM: To clone human 15ku selenoprotein gene.

METHODS: H9 human T cells were cultured in RPMI1640 medium supplemented with 100 mL/L fetal calf serum. mRNA was isolated from the cells. cDNA library was constructed by RT-PCR. The human 15ku selenoprotein gene was obtained by PCR and cloned into T vector and sequenced.

RESULTS: A unique cDNA fragment about 1244 bp was obtained. Sequence analysis identified an open reading frame within the cDNA. The gene had an in-frame TGA, which encoded selenocysteine (Sec), and a 3’-UTR SECIS element, which was required for synthesis of selenoprotein. The predicted protein molecular mass was about 15ku (162 residues). The result was identical with human liver 15ku selenoprotein gene published in Genbank.

CONCLUSION: Human 15ku selenoprotein gene can be successfully obtained from T cell line.

Role of mitochondrial dysfunction in hydrogen peroxide-induced apoptosis of intestinal epithelial cells

AIM: To study the role of mitochondrial dysfunction in hydrogen peroxide-induced apoptosis of intestinal epithelial cells.

METHODS: Hydrogen peroxide-induced apoptosis of human intestinal epithelial cell line SW-480 was established. Cell apoptosis was determined by Annexin-V and PI double-stained flow cytometry and DNA gel electrophoresis. Morphological changes were examined with light and electron microscopy. For other observations, mitochondrial function, cytochrome c release, mitochondrial translocation and membrane potential were determined simultaneously.

RESULTS: Percentage of apoptotic cells induced with 400 μmol/L hydrogen peroxide increased significantly at l h or 3 h after stimulation and recovered rapidly. Meanwhile percentage of apoptotic cells induced with 4 mmol/L hydrogen peroxide increased with time. In accordance with these changes, we observed decreased mitochondrial function in 400 μmol/L H₂O₂-stimualted cells at 1 h or 3 h and in 4 mmol/L H₂O₂-stimualted cells at times examined. Correspondingly, swelling cristae and vacuole-like mitochondria were noted. Release of cytochrome c, decreased mitochondrial membrane potential and mitochondrial translocation were also found to be the early signs of apoptosis.

CONCLUSION: Dysfunctional mitochondria play a role in the apoptosis of SW-480 cell line induced by hydrogen peroxide.

Synthesis of endotoxin receptor CD14 protein in Kupffer cells and its role in alcohol-induced liver disease

AIM: To observe the synthesis of endotoxin receptor CD14 protein and its mRNA expression in Kupffer cells (KCs), and evaluate the role of CD14 in the pathogenesis of liver injury in rats with alcohol-induced liver disease (ALD).

METHODS: Twenty-eight Wistar rats were divided into two groups: ethanol-fed group and control group. Ethanol-fed group was fed ethanol (dose of 5-12g·kg·d^-1) and control group received dextrose instead of ethanol. Two groups were sacrificed at 4 wk and 8 wk, respectively. KCs were isolated and the synthesis of CD14 protein and its mRNA expression in KCs were determined by flow cytometric analysis (FCM) or the reverse transcription polymerase chain reaction (RT-PCR) analysis. The levels of plasma endotoxin and alanine transaminase (ALT) were measured by Limulus Amebocyte Lysate assay and standard enzymatic procedures respectively, and the levels of plasma tumor necosis factor (TNF)-α and interleukin (IL)-6 were both determined by ELISA. The liver pathology change was observed under light and electric microscopy.

RESULTS: In ethanol-fed group, the percentages of FITC-CD14 positive cells were 76.23% and 89.42% at 4 wk and 8 wk, respectively. Compared with control group (4.45% and 5.38%), the difference was significant (P < 0.05). The expressions of CD14 mRNA were 7.56 ± 1.02 and 8.74 ± 1.37 at 4 wk and 8 wk, respectively, which were significantly higher compared with the control group (1.77 ± 0.21 and 1.98 ± 0.23) (P < 0.05). Plasma endotoxin levels at 4 wk and 8 wk increased significantly in ethanol-fed group (129 ± 21 ng·L^-1 and 187 ± 35 ng·L^-1) than those in control rats (48 ± 9 ng·L^-1 and 53 ± 11 ng·L^-1)(P < 0.05). Mean values of plasma ALT levels increased dramatically in ethanol-fed rats (112 ± 15 IU/L and 147 ± 22 IU/L) than those in the control animals (31 ± 12 IU/L and 33 ± 9 IU/L) (P < 0.05). In ethanol-fed rats, the levels of TNF-α were 326 ± 42 ng·L^-1 and 402 ± 51 ng·l^-1 at 4 wk and 8 wk, respectively which were significantly higher than those in control group (86 ± 12 ng·L^-1 and 97 ± 13 ng·L^-1) (P < 0.05). The levels of IL-6 were 387 ± 46 ng·L^{- 1} and 413 ± 51 ng·L^-1, which were also higher than control group (78 ± 11 ng·L^-1 and 73 ± 10 ng·L^-1) (P < 0.05). In liver section from ethanol-fed rats, there were marked pathological changes including steatosis, cell infiltration and necrosis. No marked pathological changes were seen in control group.

CONCLUSION: Ethanol administration led to a significant synthesis of endotoxin receptor CD14 protein and its gene expression in KCs, which maybe result in the pathological changes of liver tissue and hepatic functional damages.

Role of NF-κB in multiple organ dysfunction during acute obstructive cholangitis

AIM: To elucidate the role of NF-κB activation in the development of multiple organ dysfunction (MOD) during acute obstructive cholangitis (AOC) in rats.

METHODS: Forty-two Wistar rats were divided into three groups: the AOC group, the group of bile duct ligation (BDL group), and the sham operation group (SO group). All the animals in the three groups were killed in the 6th and 48th hour after operation. Morphological changes of vital organs were observed under light and electron microscopy. NF-κB activation was determined with Electrophoretic Mobility Shift Assay (EMSA). Arterial blood gas analyses and the serum levels of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine were performed. The concentrations of TNF-α and IL-6 in plasma were also measured.

RESULTS: The significant changes of histology and ultrastructure of vital organs were observed in AOC group. By contrast, in BDL group, all the features of organs damage were greatly reduced. Expression of NF-κB activation in various tissues increased in AOC group when compared to other two groups. At 6 h, the arterial pH in three groups was 7.52 ± 0.01, 7.46 ± 0.02, and 7.45 ± 0.02, and the blood pCO₂ was 33.9 ± 0.95 mmHg, 38.1 ± 0.89 mmHg, 38.9 ± 0.94 mmHg, there was difference in three groups (P < 0.05). At 48 h, the blood pHvalues in three groups was 7.33 ± 0.07, 7.67 ± 0.04, and 7.46 ± 0.03, and blood HCO₃^- was 20.1 ± 1.29 mmol·L^-1, 26.7 ± 1.45 mmol·L^-1 and 27.4 ± 0.35 mmol·L^-1, there was also difference in three groups (P < 0.05). In AOC group, Levels of LDH, ALT, BUN and creatinine were 16359.9 ± 2278.8 nkat·L^-1, 5796.2 ± 941.9 nkat·L^-1, 55.7 ± 15.3 mg/dl, and 0.72 ± 0.06 mg/dl, which were higher than in SO group (3739.1 ± 570.1 nkat·L^-1, 288.4 ± 71.7 nkat·L^-1, 12.5 ± 2.14 mg/dl, and 0.47 ± 0.03 mg/dl) (P < 0.05). Levels of plasma TNF-α and IL-6 in AOC at 48 h were 429 ± 56.62 ng·L^-1 and 562 ± 57 ng·L^-1, which increased greatly when compared to BDL group (139 ± 16 ng·L^-1, 227 ± 43 ng·L^-1) and SO group (74 ± 10 ng·L^-1, 113 ± 19 ng·L^-1) (P < 0.05).

CONCLUSION: The pathological damages and the NF-κB activation of many vital organs exised during AOC. These findings have an important implication for the role of NF-κB activation in MOD during AOC.

Effects of hydrogen peroxide on mitochondrial gene expression of intestinal epithelial cells

AIM: To study the effects of hydrogen peroxide on mitochondrial gene expression of intestinal epithelial cells in in vitro model of hydrogen peroxide-stimulated SW-480 cells.

METHODS: RNA of hydrogen peroxide-induced SW-480 cells was isolated, and reverse-transcriptional polymerase chain reaction was performed to study gene expression of ATPase subunit 6, ATPase subunit 8, cytochrome c oxidase subunit I (COI), cytochrome coxidase subuit II (COII) and cytochrome c oxidase subunit III (COIII). Mitochondria were isolated and activities of mitochondrial cytochrome c oxidase and ATPase were also measured simultaneously.

RESULTS: Hydrogen peroxide led to differential expression of mitochondrial genes with some genes up-regulated or down-regulated in a dose dependent manner. Differences were very obvious in expressions of mitochondrial genes of cells treated with hydrogen peroxide in a concentration of 400 μmol/L or 4 mmol/L. In general, differential expression of mitochondrial genes was characterized by up-regulation of mitochondrial genes in the concentration of 400 μmol/L and down-regulation in the concentration of 4 mmol/L. In consistence with changes in mitochondrial gene expressions, hydrogen peroxide resulted in decreased activities of cytochrome c oxidase and ATPase.

CONCLUSION: The differential expression of mitochondrial genes encoding cytochrome c oxidase and ATPase is involved in apoptosis of intestinal epithelial cells by affecting activities of cytochorme c oxidase and ATPase.

Intestinal damage mediated by Kupffer cells in rats with endotoxemia

AIM: To determine the in vivo effects of phagocytic blockade of Kupffer cell (KC) on the release of proinflammatory cytokines in small intestinal lesion and on the integrity of intestinal tract by using gadolinium chloride (GdCl₃) during early endotoxemia.

METHODS: Wistar rats were divided into three groups: Group A, rats were injected with endotoxin (E. coli O111:B4, a dose of 12 mg•kg⁻¹) only; Group B, rats were pretreated intravenously with 25 mg of GdCl₃ per kg 24 h are given endotoxin; and Group C, sham operation only. All animals were sacrificed 4 h after endotoxin injection. In portion of the rats of three groups, bile duct was cannulated, which the bile was collected externally. Morphological changes of ileum were observed under light microscopy and electronic microscopy. The KC were isolated from rats by collagenase perfusion and in KC, expression of TNF-α and IL-6 mRNA were determined by RT-PCR analysis. Plasma and bile TNF-α and IL-6 Levels were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS: In group A, there were neutrophil infiltration and superficial epithelial necrosis of the ileal villi, sloughing of mucosal epithelium, and disappearance of some villi. In group B, the ileal mucosal damage was much reduced. Which in group C, no significant morphological changes were seen. GdCl₃ pretreatment decreased significantly the expression of TNF-α and IL-6 mRNA in group B (4.32 ± 0.47 and 4.05 ± 0.43) when compared to group A (9.46 ± 1.21 and 9.04 ± 1.09) (P < 0.05). There was no significant expression of TNF-α and IL-6 mRNA in group C (1.03 ± 0.14 and 10.4 ± 0.13). In rats of group A, the levels of TNF-α and IL-6 in bile and plasma were 207 ± 29 ng·L^-1, 1032 ± 107 ng·L^-1, 213 ± 33 ng·L^-1, and 1185 ± 127 ng·L^-1, respectively. In group B, they were 113 ± 18 ng·L^-1, 521 ± 76 ng·L^-1, 147 ± 22 ng·L^-1, and 572 ± 54 ng·L^-1, respectively. In group C, they were 67 ± 10 ng·L^-1, 72 ± 13 ng·L^-1, 109 ± 18 ng·L^-1, and 118 ± 22 ng·L^-1 respectively. There were significant difference between the three group (P < 0.05).

CONCLUSION: KC release cytokines TNF-α and IL-6 causing damage to the integrity of intestinal epithelium and play a crucial role in the initiation and progression of intestinal mucosal damage during early endotoxemia.

Expression of CD14 protein and its gene in liver sinusoidal endothelial cells during endotoxemia

AIM: To observe expression of CD14 protein and CD14 gene in rat liver sinusoidal endothelial cells (LSECs) during endotoxemia, and the role of CD14 protein in the activation of lipopolysaccharide (LPS)-induced LSECs.

METHODS: Wistar rat endotoxemia model was established first by injection of a dose of LPS (5 mg/kg, Escherichia coli O111:B4) via the tail vein, then sacrificed after 0 h, 3 h, 6 h, 12 h, and 24 h, respectively. LSECs were isolated from normal and LPS-injected rats by an in situ collagenase perfusion technique. The isolated LSECs were incubated with rabbit anti-rat CD14 polyclonal antibody, then stained with goat anti rabbit IgG conjugated fluorescein isothiocyanate (FITC) and flow cytometric analysis (FCM) was performed. The percentage and mean fluorescence intensity (MFI) of CD14-positive cells were taken as the indexes. LSECs were collected to measure the expression of CD14 mRNA by in situ hybridization analysis. The isolated LSECs from normal rats were incubated firstly with anti-CD14 antibody, then stimulated with different concentrations of LPS, and the supernatants of these cells were then collected for measuring the levels of tumor necrosis factor (TNF)-α and Interleukin (IL)-6 with ELISA.

RESULTS: In rats with endotoxemia, LSECs displayed a strong MFI distinct from that of control rats. CD14 positive cells in rats with endotoxemia were 54.32%, 65.83%, 85.64%, and 45.65% at 3 h, 6 h, 12 h, and 24 h respectively, there was significant difference when compared to normal group of animals (4.45%) (P < 0.01). The expression of CD14 mRNA in isolated LSECs was stronger than that in control rats. In LPS group, the levels of TNF-α and IL-6 were 54 ± 6 ng·L^-1, 85 ± 9 ng·L^-1, 206 ± 22 ng·L^-1, 350 ± 41 ng·L^-1, 366 ± 42 ng. L^-1 and 103 ± 11 ng·L^-1, 187 ± 20 ng·L^-1, 244 ± 26 ng·L^-1, 290 ± 31 ng·L^-1, and 299 ± 34 ng·L^-1, respectively at different concentration points. In anti-CD14 group, the levels of TNF-α and IL-6 were 56 ± 5 ng·L^-1, 67 ± 8 ng·L^-1, 85 ± 10 ng·L^-1, 113 ± 12 ng·L^-1, 199 ± 22 ng·L^-1 and 104 ± 12 ng·L^-1, 125 ± 12 ng·L^-1, 165 ± 19 ng·L^-1, 185 ± 21 ng·L^-1, and 222 ± 23 ng·L^-1, respectively at different concentration points. There was significant difference between the two groups (P < 0.01).

CONCLUSION: LSECs can synthesize CD14 protein and express CD14 gene during endotoxemia. CD14 protein plays an important role in the activation of LPS-induced LSECs. This finding has important implications for the understanding of the mechanisms by which LPS may injure liver sinusoidal endothelial cells during sepsis.

Liver sinusoidal endothelial cell injury by neutrophils in rats with acute obstructive cholangitis

AIM: The objective of this study is to elucidate the potential role of poly-morphonuclear neutrophils (PMN) in the development of such a sinusoidal endothelial cell (SEC) injury during early acute obstructive cholangitis (AOC) in rats.

METHODS: Twenty one Wistar rats were divided into three groups: the AOC group, the bile duct ligated group (BDL group), and the sham operation group (SO group). The common bile duct (CBD) of rats in AOC group was dually ligated and 0.2 mL of the E. coli O₁₁₁ B₄ (5 × 10⁹ cfu/mL) suspension was injected into the upper segment, in BDL group, only the CBD was ligated and in SO group, neither injection of E. coli suspension nor CBD ligation was done, but the same operative procedure. Such group consisted of seven rats, all animals were killed 6 h after the operation. Morphological changes of the liver were observed under light and electron microscope. Expression of intercellular adhesion molecule-1 (ICAM-1) mRNA in hepatic tissue was determined with reverse transcription polymerase chain reaction (RT-PCR). The serum levels of alanine aminotransferase (ALT) were determined with anutoanalyger and cytokine-induced neutrophil chemoattractant (CINC) was determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS: Neutrophils was accumulated in the hepatic sinusoids and sinusoidal endothelial cell injury existed in AOC group. In contrast, in rats of BDL group, all the features of SEC damage were greatly reduced. Expression of ICAM-1 mRNA in hepatic tissue in three groups were 7.54 ± 0.82, 2.87 ± 0.34, and 1.01 ± 0.12, respectively. There were significant differences among three groups (P < 0.05). The serum CINC levels in the three groups were 188 ± 21 ng•L⁻¹, 94 ± 11 ng•L⁻¹, and 57 ± 8 ng•L⁻¹, respectively. There were also significant differences among the three groups (P < 0.05). Activity of the serum ALT was 917 ± 167 nkat•L⁻¹, 901 ± 171 nkat•L⁻¹, and 908 ± 164 nkat•L⁻¹, respectively, (P > 0.05).

CONCLUSION: Hepatic SEC injury occurs earlier than hepatic parenchymal cells during AOC. Recruitments of circulating neutrophils in the hepatic sinusoidal space might mediate the SEC injury, and ICAM-1 in the liver may modulate the PMN of accumulation.