[Assessment of neural respiratory drive in humans].

OBJECTIVE: Assessment of neural respiratory drive is useful for diagnosis of dyspnea and respiratory failure with unknown causes. The purpose of the study was to compare the sensitivity of trandiaphragmatic pressure (Pdi) and diaphragm electromyogram (EMGdi) in assessment of neural respiratory drive. METHODS: A combined catheter with 10 electrodes and 2 balloons was used to record EMGdi and Pdi during CO2 rebreathing. Three different inspiratory maneuvers-inspiration from functional residual capacity to total lung capacity (TLC), deep inspiration from functional residual capacity against closed airway (MIP), and short sharp inspiration through the nose (Sniff) were performed. Ten healthy subjects [male 4 and female 6; age (26 ± 4) years] were studied. RESULTS: Linear relationship between EMGdi and end-tidal CO2 (r = 0.83-0.98, all P < 0.01) was better than that between Pdi and end-tidal CO2 (r = 0.48-0.96, all P < 0.01) during CO2 rebreathing, Z = -2.731, P < 0.05. The slope of linear relation between EMGdi and end-tidal CO2 (16.3-32.5) was significantly higher than that between Pdi and end-tidal CO2 (0.4-11.1), Z = -3.780, P < 0.01. The maximal EMGdi derived from TLC maneuver (211 ± 48) µV was larger than those from the MIP maneuver (161 ± 48) µV and the Sniff maneuver (145 ± 37) µV, F = 5.931, P < 0.05, whereas the maximal Pdi derived from TLC maneuver (58 ± 27) cm H2O (1 cm H2O = 0.098 kPa) was significantly lower than those from the MIP maneuver (92 ± 32) cm H2O and the Sniff maneuver (95 ± 27) cm H2O, F = 5.155, P < 0.05. CONCLUSION: EMGdi is more sensitive than Pdi in the assessment of neural respiratory drive.

Transplanted endothelial progenitor cells ameliorate carbon tetrachloride-induced liver cirrhosis in rats.

Cirrhosis is the most common end stage of liver diseases, and there are no effective treatment methods. Here we evaluated the effect of endothelial progenitor cell (EPC) transplantation from rat bone marrow (BM) on the development of cirrhosis induced by carbon tetrachloride (CCl(4)). Ex vivo generated, characterized, and cultivated rat BM-derived EPCs were identified by their vasculogenic properties in vitro. EPCs from male rats were transplanted into female rats via the intraportal vein 12 weeks after they had been challenged with CCl(4), and the rats were killed 16 weeks later. The control rats received only a saline infusion. The fibrosis index and donor cell engraftment were assessed after EPC transplantation. After transplantation via the portal vein, PKH26 labeling, polymerase chain reaction, and in situ hybridization analysis revealed that the donor EPCs had adhered to the vasolateral surfaces of blood vessels and established in the liver. EPCs reduced the expression of alpha-smooth muscle actin, collagen III, and transforming growth factor beta (P < 0.05) as well as levels of aspartate aminotransferase, alanine aminotransferase, and total bilirubin in the serum (P < 0.05), but at the same time they increased the levels of albumin and Ki67. CCl(4) treatment increased the international prothrombin ratio (P < 0.05) and reduced albumin levels, whereas EPCs restored these parameters to normal levels. These results suggest that EPC transplantation could play a role in regulating hepatocyte regeneration and ameliorating established liver cirrhosis.

HBV infection involving in hepatic progenitor cells expansion in HBV-infected end-stage liver disease.

BACKGROUND/AIMS: In chronic hepatitis B, hepatic progenitor cells (HPCs) activation and ductular reactions occurred in periportal and portal area. However, the association between hepatitis B virus (HBV) infection and HPCs activation remains unknown. We aim to investigate the expansion of HPCs in patients with end-stage chronic hepatitis B and its relationship to HBV infection. METHODOLOGY: Liver biopsy specimens from 16 cases of end-stage liver disease caused by chronic hepatitis B were studied. The quantities of serum HBV DNA were available in 13 patients. The number of HPCs and the area of ductular reactions were quantitively analyzed on the cytokeratin 7 (CK7)-stained sections. Double-staining combined either HBsAg or HBcAg with CK7 were performed to assess the histological relationship between HBV infection and HPCs activation. RESULTS: All of the sections showed liver cirrhosis and severe inflammation (HAI ranged from 12 to 17). The number of HPCs correlated with the area of ductular reactions positively. Multivariate analysis showed that serum HBV DNA level was independently associated with HPCs activation and ductular reactions. Moreover, the expression area of HBsAg in liver tissue correlated with HPCs activation positively. CONCLUSIONS: In end-stage of chronic hepatitis B, the expansion of hepatic progenitor cells and ductular reactions were extensive. HBV infection may be involved in the proliferation of progenitor cells in cirrhotic environments.

[Effect of glia maturation factor beta on the activation of hepatic stellate cells and on liver fibrosis].

OBJECTIVE: To further study the mechanism of the inhibitory effect of interferon beta-1a (IFN beta-1a) on the activation of human hepatic stellate cell (HSC) LX-2, and to analyze the differences on the protein expression in LX-2 induced by I IFN beta-1a. METHODS: Cultured LX-2 cells were treated with 2000 U/ml IFN beta-1a for 48 h. Two-dimensional gel electrophoresis (2-DE) was performed to compare protein patterns of the control (untreated) and IFN beta-1a treated LX-2 and for quantitative and qualitative analyses of protein expression. A rat liver fibrosis model was established and the rats were sacrificed and their various tissues were obtained for the same analyses. Western blotting and RT-PCR were used to validate the expression of the changed proteins after treatment of IFN beta-1a in LX-2 cells and of various tissues of the rats. RESULTS: 708 +/- 25 spots were detected in control LX-2 cells and 804 +/- 32 spots in IFN beta-1a-treated LX-2 cells. A match rate of 73%-82% was achieved. The results also showed that 31 protein spots displayed quantitative changes in expression after IFN beta-1a treatment. Of the 31 spots, 21 proteins were identified, of which, one was newly found, two were enhanced in abundance and 18 showed lower expressions. The newly found protein was glia maturation factor beta (GMF beta). The treatment of LX-2 with IFN beta-1a increased the production of GMF beta(GMF beta) protein in comparison with the untreated cells (t=1.81, P < 0.01). The expression of GMF beta protein (1.81 vs 0.10) and mRNA (0.85 vs 0.12) were more in the normal liver tissues than in the cirrhotic liver tissues (t=2.53, 2.13 respectively, P < 0.01). The expressions of GMF beta protein and mRNA were weak in rat heart and lung tissues, however, they were strong in rat liver, kidney, spleen and brain tissues (t=1.91, 1.94 respectively, P < 0.01). CONCLUSION: There is a significant difference of protein expression levels between IFN beta-1a untreated and treated LX-2 cells. These proteins, especially GMF beta, may be involved in an inhibition process of IFN beta-1a on activation and apoptosis of LX-2 cells. This proteome study may be useful in further studies of the relationship of IFN beta-1a treatment and human liver diseases.

In vitro interactions between rat bone marrow-derived endothelial progenitor cells and hepatic stellate cells: interaction between EPCs and HSCs.

Transplantation of bone marrow (BM)-derived endothelial progenitor cells (EPCs) has been reported to improve liver fibrosis, but there is no direct evidence for the mechanism of improvement. We investigated the mechanism in vitro by coculturing BM-derived EPCs with activated hepatic stellate cells (HSCs) to mimic the hepatic environment. EPCs and HSCs were cultured alone and indirectly cocultured at a 1:1 ratio in a Transwell system. The characteristics of HSCs and EPCs were examined at different time points. An invasion assay showed the time-dependent effect on degradation of the extracellular matrix (ECM) layer in EPCs cultured alone. Real-time PCR and enzyme-linked immunosorbent assay analysis revealed that EPCs served as a source of matrix metalloproteinase-9 (MMP-9), and MMP-9 expression levels significantly increased during the 2 d of coculture. CFSE labeling showed that EPCs inhibited proliferation of HSCs. Annexin-V/PI staining, erminal deoxynucleotidyl transferase X-dUTP nick end labeling analysis, and (cleaved) caspase-3 activity revealed that EPCs promoted HSC apoptosis. However, the proliferation and apoptosis of EPCs were unaffected by cocultured HSCs. Coculturing increased the expression of inducible nitric oxide synthase, vascular endothelial growth factor, and hepatocyte growth factor (HGF) in EPCs, promoted differentiation of EPCs, and reduced the expression of types I and III collagens and transforming growth factor beta 1. Knockdown of HGF expression attenuated EPC-induced activation of HSC apoptosis and profibrotic ability. These findings demonstrated that BM-derived EPCs could degrade ECM, promoting activated HSC apoptosis, suppressing proliferation and profibrotic ability of activated HSCs. HGF secretion by EPCs plays a key role in inducing activated HSC apoptosis and HSC profibrotic ability.