[The change in expression of Toll-like receptor 4 on peripheral blood mononuclear cell after continuous renal replacement therapy in patients with sepsis].

OBJECTIVE: To explore the change in Toll-like receptor 4 (TLR4) of peripheral blood mononuclear cell (PBMC) and the expression of cytokines in patients with sepsis, and to investigate the role of continuous renal replacement therapy (CRRT) in its modulation. METHODS: A clinical study was performed in 13 patients with sepsis which were divided into improved group (n=7) and healing group (n=6), according to their outcome. Another 6 healthy individuals served as normal control. The mRNA expression of TLR4 on PBMC was detected by reverse transcription-polymerase chain reaction (RT-PCR), the protein expression of TLR4 on PBMC was assayed with flow cytometry, the expressions of IL-6 and TNF-alpha were measured by enzyme linked immunoadsorbent assay (ELISA). RESULTS: TLR4 mRNA, IL-6, TNF-alpha, and TLR4 protein expressions were upregulated markedly in patients suffering from sepsis. The above parameters were decreased significantly after CRRT (all P<0.05) and in the same time, the clinic condition turn up, in the meanwhile, the expression of TLR4 went down, but it still have some expression on monocyte in improved group. CONCLUSION: The down regulation of TLR4 through CRRT may imply an important mechanism in the CRRT on patients with sepsis.

[Role of trefoil peptides in modulation of gastric adaptation to stress].

OBJECTIVE: To investigate the role of trefoil peptides in modulation of gastric adaptation to water restraint stress (WRS) in rats. METHODS: Wistar rats were exposed to single or repeated WRS for 4 hours every other day for up to 6 days, gastric mucosal blood flow (GMBF) was measured by LDF-3 flowmeter, the extent of gastric mucosal lesions was evaluated grossly and histologically, and expression of PS2 intestinal trefoil peptide (ITF), cyclooxygenase (COX-2), inducible nitric oxide synthase (iNOS) and transferase growth factor-alpha (TGF-alpha) were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. RESULTS: One application of WRS produced extensive gastric mucosal erosion. With repeated WRS, the gastric mucosa became adapted to the stress of WRS, and the ulcerative index (UI) was reduced by 22.0% that of one WRS challenge after four consecutive WRS. Expression of PS2 was markedly decreased and expression of ITF, COX-2, iNOS and TGF-alpha were markedly increased after single stress. But this adaptation to WRS was accompanied by increased GMBF and active cell proliferation in the neck region of gastric glands, and by increased expression of PS2, ITF, TGF-alpha, but reduced expression of COX-2 and iNOS. CONCLUSION: Gastric adaptation to WRS injury involves enhanced cell proliferation, increased expression of PS2, ITF, TGF-alpha and reduced expression of COX-2 and iNOS, suggesting trefoil peptides might play an important modulating role in this phenomenon.

Serial analysis of gene expression in mice with lipopolysaccharide-induced acute lung injury.

OBJECTIVE: To monitor the systemic gene expression profile in a murine model of lipopolysaccharide-induced acute lung injury. METHODS: Acute lung injury was induced by intratracheal injection of lipopolysaccharide in 3 mice. Another 3 normal mice receiving same volume of normal saline were taken as the controls. The comprehensive gene expression profile was monitored by the recently modified long serial analysis of gene expression. RESULTS: A total of 24,670 tags representing 12,168 transcripts in the control mice and 26,378 tags representing 13,397 transcripts in the mice with lung injury were identified respectively. There were 11 transcripts increasing and 7 transcripts decreasing more than 10 folds in the lipopolysaccharide-treated mice. The most overexpressed genes in the mice with lung injury included serum amyloid A3, metallothionein 2, lipocalin 2, cyclin-dependent kinase inhibitor 1A, lactate dehydrogenase 1, melatonin receptor, S100 calcium-binding protein A9, natriuretic peptide precursor, etc. Mitogen activated protein kinase 3, serum albumin, complement component 1 inhibitor, and ATP synthase were underexpressed in the lung injury mice. CONCLUSIONS: Serial analysis of gene expression provides a molecular characteristic of acute lung injury.

Cyclooxygenase 2, pS2, inducible nitric oxide synthase and transforming growth factor alpha in gastric adaptation to stress.

AIM: To determine the role of mucosal gene expression of cyclooxygenase 2 (COX-2), pS2 (belongs to trefoil peptides), inducible nitric oxide synthase (iNOS) and transforming growth factor alpha (TGFalpha) in gastric adaptation to water immersion and restraint stress (WRS) in rats. METHODS: Wistar rats were exposed to single or repeated WRS for 4 h every other day for up to 6 d. Gastric mucosal blood flow (GMBF) was measured by laser Doppler flowmeter-3. The extent of gastric mucosal lesions were evaluated grossly and histologically and expressions of COX-2, pS2,iNOS and TGFalpha were determined by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot. RESULTS: The damage to the surface of gastric epithelium with focal areas of deep haemorrhagic necrosis was induced by repeated WRS. The adaptative cytoprotection against stress was developed with activation of cell proliferation in the neck regions of gastric glands. The ulcer index (UI) in groups II, III and IV was markedly reduced as compared with group I (I: 47.23+/-1.20; IV: 10.39+/-1.18,P<0.01). GMBF significantly decreased after first exposure to WRS with an adaptive increasement of GMBF in experimental groups after repetitive challenges with WRS. After the 4th WRS, the value of GMBF almost restored to normal level (I: 321.87+/-8.85; IV: 455.95+/-11.81, P<0.01). First WRS significantly decreased the expression of pS2 and significantly increased the expressions of COX-2, iNOS and TGFalpha. After repeated WRS, pS2 and TGFalpha expressions gradually increased (pS2: I: 0.37+/-0.02; IV: 0.77+/-0.01; TGFalpha: I: 0.86+/-0.01; IV: 0.93+/-0.03, P<0.05) with a decrease in the expressions of COX-2 and iNOS (COX-2: I: 0.45+/-0.02; IV: 0.22+/-0.01; iNOS: I: 0.93+/-0.01; IV: 0.56+/-0.01, P<0.01). Expressions of pS2, COX-2, iNOS and TGFalpha showed regular changes with a good relationship among them. CONCLUSION: Gastric adaptation to WRS injury involves enhanced cell proliferation, increased expression of pS2 and TGFalpha, and reduced expression of COX-2 and iNOS. These changes play an important role in adaptation of gastric mucosa after repeated WRS.

Role of TFF in healing of stress-induced gastric lesions.

AIM: To determine the changes of pS2 and ITF of TFF expression in gastric mucosa and the effect on ulcer healing of pS2, ITF to Water-immersion and restraint stress (WRS) in rats. METHODS: Wistar rats were exposed to single or repeated WRS for 4 h every other day for up to 6 days.Gastric mucosal blood flow (GMBF) was measured by LDF-3 flowmeter and the extent of gastric mucosal lesions were evaluated grossly and histologically. Expression of pS2 and ITF mRNA was determined by RT-PCR. Immunohistochemistry was used to further detect the expression of pS2 and ITF. RESULTS: WRS applied once produced numerous gastric mucosal erosions, but the number of these lesions gradually declined and GMBF restored at 2, 4, 8 h after stress. The area of gastric mucosal lesion was reduced by 64.9 % and GMBF was increased by 89.8 % at 8 h. The healing of stress-induced ulcerations was accompanied by increased expression of pS2 (0.51+/-0.14 vs 0.77+/-0.11, P<0.01) and ITF (0.022+/-0.001 vs 0.177+/-0.010, P<0.01). The results were demonstrated further by immunohistochemistry of pS2 (0.95+/-0.11 vs 1.41+/-0.04, P<0.01) and ITF (0.134+/-0.001 vs 0.253+/-0.01,P<0.01). With repeated WRS, adaptation to this WRS developed, the area of gastric mucosal lesions was reduced by 22.0 % after four consecutive WRS. This adaptation to WRS was accompanied by increased GMBF (being increased by 94.2 %), active cell proliferation in the neck region of gastric glands, and increased expression of pS2 (0.37+/-0.02 vs 0.77+/-0.01, P<0.01) and ITF (0.040+/- 0.001 vs 0.372+/-0.010, P<0.01). The result was demonstrated further by immunohistochemistry of pS2 (0.55+/-0.04 vs 2.46+/-0.08, P<0.01) and ITF (0.134+/-0.001 vs 0.354+/-0.070, P<0.01). CONCLUSION: TFF may not only participate in the early phase of epithelial repair known as restitution (maked by increased cell migration), but also play an important role in the subsequent, protracted phase of glandular renewal(made by cell proliferation).