Anti-Inflammatory Effects of Schisandrin B on LPS-Stimulated BV2 Microglia via Activating PPAR-γ.

Schisandrin B (Sch B), a dibenzocyclooctadiene lignan isolated from Schisandra chinensis (Turcz.) Baill, has been shown to have anti-inflammatory effect. The purpose of this study was to evaluate the effect of Sch B on LPS-induced inflammation in microglia and to investigate the molecular targets of Sch B. BV2 cells were stimulated by LPS in the presence or absence of Sch B. The results showed that the levels of TNF-α, IL-6, IL-1ß, and PGE2 upregulated by LPS were significantly suppressed by Sch B. LPS-induced NF-κB activation was also inhibited by Sch B. Furthermore, Sch B was found to upregulate the expression of PPAR-γ in a concentration-dependent manner. In addition, the inhibition of Sch B on TNF-α, IL-6, IL-1ß, and PGE2 production were reversed by PPAR-γ antagonist GW9662. In conclusion, these results suggested that Sch B inhibited LPS-induced inflammatory response by activating PPAR-γ.

The ratio of Th17/Treg cells as a risk indicator in early acute respiratory distress syndrome.

INTRODUCTION: Recent studies have revealed that lung inflammation mediated by CD4+ T cells may contribute to the pathogenesis of acute respiratory distress syndrome (ARDS). The imbalance between CD4 + CD25 + Foxp3 + regulatory T (Treg) cells and T helper (Th)17 cells has been found in a number of different inflammation and autoimmune diseases, while the role of the Th17/Treg balance in ARDS remains largely unknown. The aim of this study was to investigate the Th17/Treg pattern and its impact on disease severity and outcomes in patients with ARDS. METHODS: This prospective, observational study enrolled 79 patients who fulfilled the Berlin definition of ARDS and 26 age- and sex-matched healthy controls. Circulation Th17 and Treg cell frequencies were analyzed by flow cytometry, and the expressions of Th17- and Treg-related cytokines in serum were measured by enzyme-linked immunosorbent assay (ELISA). Acute Physiologic and Chronic Health Evaluation (APACHE) II score, Sequential Organ Failure Assessment (SOFA) score, and the Lung Injury Score were also calculated at enrollment. RESULTS: Within 24 hours after the onset of ARDS, the changes of peripheral circulating Th17 and Treg cell frequencies gradually increased from mild to severe ARDS. Th17/Treg ratio was positively correlated with APACHE II score, SOFA score, and Lung Injury Score, while negatively correlated with PaO2/FiO2. The areas under the receiver operating characteristic (AUC) curves of Th17/Treg ratio for predicting 28-day mortality in ARDS patients was higher than that of APACHE II score, SOFA score, Lung injury score, as well as PaO2/FiO2. Using a Th17/Treg ratio cutoff value of >0.79 to determine 28-day mortality, the sensitivity was 87.5% with 68.1% specificity. Multivariate logistic regression showed Th17/Treg ratio >0.79 (odds ratio = 8.68, P = 0.002) was the independent predictor for 28-day mortality in patients with ARDS. Finally, cumulative survival rates at 28-day follow-up also differed significantly between patients with Th17/Treg ratio >0.79 and ≤0.79 (P <0.001). CONCLUSIONS: The Th17/Treg imbalance favoring a Th17 shift represents a potential therapeutic target to alleviate lung injury and a novel risk indicator in patients with early ARDS.

ß-catenin induces A549 alveolar epithelial cell mesenchymal transition during pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease characterized by expansion of the fibroblast and myofibroblast population and extracellular matrix deposition. Although the pathogenic mechanisms of IPF remain to be fully elucidated, there is emerging evidence that fibroblasts and myofibroblasts may be derived partially from alveolar epithelial cells by epithelial­mesenchymal transition (EMT). In the present study, A549 cells were treated with different concentrations of Wnt1 and the results indicated that the mRNA and protein expression levels of vimentin, α­smooth muscle actin (α­SMA) and collagen Ⅰ gradully increased and those of E­cadherin gradully decreased in a concentration­dependent manner. Furthermore, the A549 cells were transfected with ß­catenin plasmid cells, revealing phenotypic changes in the cells from a pebble to a fusiform shape. The mRNA and protein expression levels of of vimentin, α­SMA and collagen Ⅰ increased significantly, whereas those of E­cadherin decreased significantly. The present study examined the roles of alveolar epithelial cell injury and profibrogenic cytokine release in EMT and their association with the Wnt/ß­catenin signaling pathway in a mouse model of bleomycin­induced pulmonary fibrosis. Bronchoalveolar fluid was obtained 7 days after treatment with bleomycin and the A549 cells were incubated for 48 h. An increase in the expression levels of the mesenchymal markers, α­SMA, vimentin and collagen Ⅰ, and a concomitant decrease in the expression of the epithelial marker, E­cadherin were observed. This corresponded with an increased expression of ß­catenin. When the A549 cells were infected with a lentivirus expressing ß­catenin shRNA, no significant increase was observed in the expression of the mesenchymal cell markers and the expression of E­cadherin did not decrease. These findings demonstrated that activation of the Wnt signaling pathway was capable of inducing an EMT program in the lung epithelial cells through ß­catenin and that injured alveolar epithelium activated the Wnt/ß­catenin signaling pathway, thereby inducing the expansion of the fibroblast/myofibroblast population through EMT. These results suggested that ß­catenin was involved in the formation of lung fibrosis and may provide a theoretical basis for the treatment of IPF.

Effect of the Wnt1/ß-catenin signalling pathway on human embryonic pulmonary fibroblasts.

Idiopathic pulmonary fibrosis (IPF) is a fibrotic lung disease associated with a high rate of mortality, characterised by an accumulation of fibroblasts/myofibroblasts in the fibroblastic foci (FF) and by an excessive deposition of extracellular matrix (ECM) in the lung parenchyma. The pathogenesis of this fatal disorder remains unclear. Previous evidence suggests that myofibroblasts are key effectors of the deposition of ECM. In the present study, human embryonic pulmonary fibroblast (HEPF) cells were incubated with different concentrations of Wnt1. The present study revealed that cell proliferation improved following stimulation using different concentrations of Wnt1 in a concentration-dependent manner. When the concentration exceeded 20 µg/l, cell proliferation was significant (P<0.05) and the cell expression of α-SMA, vimentin and collagen I mRNA, as well as protein expression, significantly increased (P<0.05). Bronchoalveolar lavage fluid (BALF) was then obtained from bleomycin (BLM)-induced models of pulmonary fibrosis. HEPF cells were cultured with Dulbecco's modified Eagle's medium plus BALF. The mRNA and protein expression of α-SMA, vimentin and collagen I significantly increased and these increases were associated with ß-catenin. Furthermore, following being infected with the lentivirus expressing ß-catenin shRNA, HEPF cells were cultured with BALF. However, the mRNA and protein expression of α-SMA, vimentin and collagen I did not increase significantly. The present study suggested that the Wnt1/ß-catenin signalling pathway can promote HEPF cell proliferation and induced HEPF cells can change into myofibroblasts and promote ECM deposition. These findings may provide a theoretical basis for the treatment of IPF.

Inhibition of epithelial-mesenchymal transition in A549 cell by transfected Napsin A.

BACKGROUND: Epithelial-mesenchymal transition is a cellular process characterized by the loss of cell adhesion, inhibition of E-cadherin expression, and increased cell mobility. Cells without Napsin A are susceptible to transition. Further studies are required to investigate whether this transition can be reversed by restoration of Napsin A. METHODS: A Napsin A expression vector PLJM1-Napsin A plasmid was constructed and then transfected into the epithelial cell line A549 by lentivirus transfection to obtain A549-PLJM1-Napsin A cell line. Cell proliferation was assayed by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide and cell cycle was measured by flow cytometry. The E-cadherin, type I collagen, and focal adhesion kinase mRNA level was detected by reverse transcription-polymerase chain reaction. The Napsin A, E-cadherin, type I collagen, and focal adhesion kinase protein level in A549 cells was detected by Western blotting. RESULTS: Transforming growth factor-b1 induced epithelial-mesenchymal transition in A549 cells, as demonstrated by significant reduction of E-cadherin mRNA and protein levels (P < 0.01) as well as up-regulation of type I collagen (P < 0.01). Transfection of Napsin A in A549 cells can partially block the transforming growth factor-b1-regulated expression of E-cadherin and type I collagen (P < 0.01). In addition, transforming growth factor-b1-induced cell proliferation was inhibited by Napsin A (P < 0.01). Further study demonstrated that Napsin A caused G(0)/G(1) arrest and inhibited the expression of focal adhesion kinase (P < 0.01), a key protein in the integrin signaling pathway, in the in vitro epithelial-mesenchymal transition model. CONCLUSIONS: Sustained Napsin A expression in A549 cells can inhibit the transforming growth factor-b1-induced epithelial-mesenchymal transition. This may be due to the Napsin A-mediated inhibition of focal adhesion kinase expression and integrin signaling pathway.

Changes in pathological pattern and treatment regimens based on repeat renal biopsy in lupus nephritis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Relapses occur frequently in patients with lupus nephritis. Renal biopsy is the gold standard for assessing renal activity and hence guiding the treatment. Whether repeat renal biopsy is helpful during flares of lupus nephritis remains inconclusive. In the present study, we retrospectively reviewed the patients with lupus nephritis who had more than one renal biopsy with the hope to find the clinical value of repeat biopsy.</p><p><b>METHODS</b>Patients who had a diagnosis of lupus nephritis and two or more renal biopsies were selected from the database of the patient pathology registration at this renal division. Renal biopsy was evaluated according to the International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification of lupus nephritis. The pathological patterns and treatment regimens were analyzed after a repeat biopsy.</p><p><b>RESULTS</b>We identified 44 systemic lupus erythematosus patients with serial renal biopsies. In total, there were 94 renal biopsies. Overall, the pathological transition occurred in 64% instances according to the ISN/RPS class. When the transition was analyzed according to proliferative, membranous or mix lesions, it showed different profile: 35% in patients with proliferative lesion, 23.5% patients with mix lesions, 100% in patients with pure membranous lesion. The pathological transition could not be predicted by any clinical characteristics. After the repeat renal biopsy, 34% of patients had a change in their treatment regimens.</p><p><b>CONCLUSIONS</b>The pathological conversion was very prevalent in patients with lupus nephritis. However, the transitions became less prevalent when they were analyzed according to pure membranous, proliferative, and mix lesion. Repeat biopsy might be helpful to avoid unnecessary increased immunosuppression therapy.</p>

[Therapeutic effects and mechanism of saikosaponin-d in mice with bleomycin-induced pulmonary fibrosis].

OBJECTIVE: To study the therapeutic effects and mechanism of saikosaponin-d (SSd) in mice with bleomycin (BLM)-induced pulmonary fibrosis. METHODS: According to the random number table, 180 mice were randomly divided into 5 groups. Four groups were pulmonary fibrosis models. Fibrosis model mice were established by intratracheal injection of bleomycin (5 mgxkg(-1)). They were BLM, DXM, SSd and SSd + DXM groups (n = 40 each). At 1 hour post-modeling, DXM, SSd and SSd + DXM groups were injected ip with dexamethasone (DXM, 5 mgxkg(-1)xd(-1), 0.1 ml), SSd (1.8 mgxkg(-1)xd(-1), 0.18 ml), DXM + SSd (0.28 ml) respectively qd until Day 28. BLM group was similarly dosed with normal saline. In addition, a normal control group (NC group, n = 20) treated likewise. The mice were anesthetized and sacrificed at Days 3, 7, 14, 28 for harvests of serum and lung tissue samples. The conventional histopathological changes of lung tissue were observed. Except for NC group, modeling groups of mice were used to observe the natural survival rate. Such indices as superoxide dismutase (SOD) and malonaldehyde (MDA) were examined both in lung tissue and serum samples. And hydroxyproline (HYP) was tested only in lung tissue. RESULTS: SSd could markedly increase the survival rate (80.0% in SSd and SSd + DXM groups vs 50.0% in BLM group, P < 0.05) and reduce alveolitis and fibrosis in mice. In comparison with BLM group, the levels of HYP of three treatment groups (DXM, SSd and SSd + DXM) in lung tissue was significantly lower (P < 0.05) at Days 14 and 28. The levels of MDA both in serum and lung tissue were significantly lower at Days 3, 7 and 14 (P < 0.05). The serum level of SOD was significantly higher at Days 3, 7 and 14 while the level of SOD in lung tissue was significantly higher at Days 3 and 7 (P < 0.05, P < 0.01). CONCLUSIONS: SSd has marked therapeutic effects upon bleomycin-induced pulmonary fibrosis in mice. And the mechanism may be associated with its anti-lipid peroxidation effect.

[Effect of Napsin A transfection into type II alveolar epithelial cells on pulmonary fibrosis].

OBJECTIVE: To study the in vitro effect and mechanism of Napsin A gene transfection into type II alveolar epithelial cells on pulmonary fibrosis. METHODS: A recombinant lentiviral plasmid PLJM1-Napsin A was constructed and transfected into human type II alveolar epithelial cell line A549. The model of pulmonary fibrosis was established by the in vitro stimulation of A549 cells by transforming growth factor beta-1 (TGF-ß1). The morphological changes were observed continuously under inverted microscopy. The proliferation of transgenic and non-transgenic cells was detected by MTT. To observe the degree of epithelial-mesenchymal transition (EMT) by TGF-ß1 intervening A549 cells, the expressions of E-cadherin and fibronectin were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Lastly the protein expression of focal adhesion kinase (FAK) was detected by Western blot to investigate the mechanism. RESULTS: The result of sequencing the recombinant lentiviral plasmid PLJM1-Napsin A was the same as the design sequence. Napsin A mRNA and protein were expressed in transgenic A549 cells (P<0.01). The model of pulmonary fibrosis was established successfully based on the morphology of transformed interstitial cell. As compared with the control group, the proliferation rate of transgenic cells decreased significantly (P<0.05). The mRNA and protein expression of E-cadherin significantly decreased in the model of pulmonary fibrosis (P<0.01), while the expression of fibronectin markedly increased (P<0.01). But the change rate of transgenic cells decreased (P<0.01, P<0.05). The expression of FAK was significantly elevated after the stimulation of TGF-ß1 (P<0.01). But the upward trend of the transgenic cells was smaller as compared with the control group (P<0.01). CONCLUSION: Pulmonary fibrosis may be suppressed by the transfection of Napsin A gene into type II alveolar epithelial cells. And the mechanism may be through the inhibition of integrin signal transduction.

[Human lamada-interferon expressed in BHK-21 cell line and its bioactivity].

AIM: To construct the eukaryotic expressing vector PCAGG -HuIFN-lambda1 and PCAGG-HuIFN-lambda2 and to study the biological activity of HuIFN-lambda1and HuIFN-lambda2. METHODS: The cDNA fragment encodding HuIFN-lambda1 and HuIFN-lambda2 was amplified from the total RNA extracted from virus-induced HeLa cells by RT-PCR. Then it was cloned into the eukaryotic expressing vector PCAGG-EGFP. The recombinant was transfected into BHK-21 cells. VSV*GFP-A549 system was used to measure the anti-virus activity.The constructed cell line MDBK-Mxp-Luc was used to study the characteristics of MxA protein induced by the products of PCAGG-HuIFN-lambda1 and PCAGG-HuIFN-lambda2. RESULTS: The recombinant vector HuIFN-lambda1-PMD18-T Vector was enzymed by Sac I and Xho I while HuIFN-lambda2-PMD18-T Vector was enzymed by Sac I and Sal I. The fragments were both 610 bp and they were consistent with nucleotide sequences reported in GenBank. The anti-virus activity of protein expressed by PCAGG-HuIFN-lambda1 and PCAGG-HuIFN-lambda2 was 10(4) IU/mL and 10(2) IU/mL, respectively. The protein expressed by PCAGG-HuIFN-lambda1 and PCAGG-HuIFN-lambda2 induced the expression of the anti-virus protein MxA. The expression of protein MxA induced by PCAGG-HuIFN-lambda1 increased with the passage of time, reaching the peak during 9 to 12 hours and disappearing in 24 hours. CONCLUSION: The eukaryotic expressing vector of PCAGG-HuIFN-lambda1 and PCAGG-HuIFN-lambda2 has been successfully constructed and transiently expressed in BHK-21 cells. The anti-virus activity of the products is closely correlated with inducing the expression of anti-virus protein MxA.

Effect of NaCl and Helicobacter pylori vacuolating cytotoxin on cytokine expression and viability.

AIM: To determine whether Helicobacter pylori (H pylori) vacuolating cytotoxin (VacA) regulates release of pro-inflammatory cytokines (IL-1beta, IL-8, TNF-alpha, and IL-6) or alters gastric epithelial cell viability and to determine whether NaCl affects these VacA-induced changes. METHODS: Vacuolating activity was determined by measuring the uptake of neutral red into vacuoles of VacA-treated human gastric epithelial (AGS) cells. AGS cell viability was assessed by direct cell counting. Specific enzyme-linked immunosorbent assays (ELISA) and reverse transcriptase-polymerase chain reaction(RT-PCR) were performed to examine the effects of H pylori VacA and NaCl on cell pro-inflammatory cytokine production in AGS cells. Immunohistochemical staining of gastric tissue from Mongolian gerbils was used to confirm VacA-induced pro-inflammatory cytokine production and the effects of NaCl on this VacA-induced response. RESULTS: Addition of VacA alone reduced AGS cell viability (P < 0.05), and this reduction was enhanced by high doses of NaCl (P < 0.05). VacA alone induced expression of TNF-alpha, IL-8 and IL-1beta, while NaCl alone induced expression of TNF-alpha and IL-1beta. Changes in mRNA levels in the presence of both VacA and NaCl were more complicated. For the case of TNF-alpha, expression was dose-dependent on NaCl. IL-6 mRNA was not detected. However, low levels of IL-6 were detected by ELISA. Positive immunohistochemical staining of IL-1, IL-6, and TNF-alpha was found in gastric tissue of H pylori-infected gerbils fed with either a normal diet or a high salt diet. However, the staining of these three cytokines was stronger in H pylori-infected animals fed with a 5 g/kg NaCl diet. CONCLUSION: VacA decreases the viability of AGS cells, and this effect can be enhanced by NaCl. NaCl also affects the production of pro-inflammatory cytokines induced by VacA, suggesting that NaCl plays an important role in H pylori-induced gastric epithelial cell cytotoxicity.

[Detection of telomerase activity in bronchoscopic brush-off samples in patients with lung cancer].

BACKGROUND AND OBJECTIVE: Recent studies have shown that activation of telomerase plays an important role in carcinogenesis. However, there was few report on the level of telomerase activity in small samples from the patients with lung cancer. This study was designed to investigate the diagnostic significance of the detection of telomerase activity in bronchoscopic brush-off cells from the patients with lung cancer. METHODS: Telomeric repeat amplification protocol(TRAP)-based telomerase polymerase chain reaction(PCR)-enzyme-linked immunosorbent assay (ELISA) TRAP-PCR-silver staining were employed to detect telomerase activity in 56 samples of brushing cells from the patients with lung cancer and 10 samples with inflammation. RESULTS: The positive rate of telomerase activity in 56 biopsy samples of lung cancer group was significantly higher than that in inflammation group (P < 0.001). The sensitivity, specificity, and accuracy of detection of telomerase activity was 87.5%, 83.3%, and 86.3%, respectively. There was no significant difference in the positive rate of telomerase activity between central lung cancer and peripheral lung cancer. Positive rate of detection of telomerase activity in bronchoscopic brush-off cells was 46.4%. The positive rate of telomerase activity detected in TRAP-PCR-ELISA was higher than that detected in TRAP-silver staining, but the significant difference was not found. It was found that samples with low absorbing value detected in the quantified way would show weak positive with less ladder bands or vague ladder bands if detected in the latter way. CONCLUSION: The telomerase activity may be a good marker for diagnosis of lung cancer. Combined with cytologic measure, it is possible to raise the early diagnostic rate of lung cancer.