Round Many acute lung injuries (ALI) can develop into acute respiratory distress syndrome (ARDS) with diffuse pulmonary fibrosis [13], which could lead to respiratory failure [4]. Occurrence of ALI and ARDS can be as a consequence of exposure to lipopolysaccharides (LPSs), endotoxins made by Gramnegative bacteria. Previous research have identified that focal aggregation of lung fibroblasts occurred prior to formation of fibrosis [5], implying that aberrant proliferation of fibroblasts requires place inside the early stages of ALIARDS. Pulmonary fibrosis is characterized by fibroblast proliferation and differentiation to myofibroblast that happen to be responsible for production of collagen [6,7]. Our preceding studies have shown that LPS was capable to directly induce secretion of collagen in main cultured mouse lung fibroblasts through Tolllike receptor 4 (TLR4)mediated activation on the phosphoinositide3kinaseAkt (PI3KAkt) pathway [8,9]. LPS was also reported to induce fibroblasts proliferation [10], downregulate phosphatase and tensin homolog (PTEN) expression [11,12]. The PTEN gene is recognized as a tumor suppressor with dephosphorylation activity [13]. Downregulation of PTEN expression and suppression of its dephosphorylation activity induce proliferation and inhibit apoptosis of glioma cells via activation in the PI3KAktglycogen synthase kinase three (GSK3) pathway, suggesting that PTEN may perhaps be involved in inactivation of PI3K signaling [14]. PTEN Cephapirin Benzathine custom synthesis restoration was also related towards the inhibition of differentiation of human lung fibroblasts into myofibroblasts via extracellular signalrelated kinase (ERK)Akt inhibition [15]. The damaging regulatory part of PTEN around the PI3KAkt pathway suggests that, without having LPS Starch Inhibitors Related Products stimulation, PTEN prevents the proliferation of lung fibroblasts, and that overexpression of PTEN may possibly abrogate the fibroblast proliferation, differentiation, activation of PI3KAktGSK3 and collagen secretion induced by LPS. Thus, the mechanism by which PTEN is straight involved in LPSinduced fibroblast proliferation by means of regulation with the PI3KAktGSK3 pathway needs further elucidation. Within the present study we investigated the function of PTEN in LPSinduced lung fibroblast proliferation differentiation and collagen secretion, and explored the potential mechanism by which overexpression of PTEN inhibits LPSinduced lung fibroblast proliferation, differentiation, activation of PI3KAktGSK3 pathways and collagen secretion. ResultsPTEN expression and dephosphorylation activity in mouse lung fibroblasts transfected with Pten overexpression lentivirusPten mRNA via realtime PCR and PTEN protein by means of Western blot. Malachite greenbased assay was used to measure the PTEN dephosphorylation activity. Levels of Pten mRNA and PTEN protein, and the dephosphorylation activity of PTEN, have been drastically lowered in the EmptyLPS group (cells transfected using the empty vector and treated with LPS), compared using the cells transfected with the empty vector but devoid of LPS (Empty group). These levels were drastically improved in the PTENLPS group (Ptentransfected cells treated with LPS) 72 h following LPS challenge (p 0.05), in comparison with the EmptyLPS group. This indicates that LPS inhibited PTEN expression in nontransfected control cells, and that the PTEN lentiviral overexpression vector successfully improved PTEN expression within the transfected primary mouse lung fibroblasts (Figure 1A). In Ptentransfected cells treated with LPS, therapy together with the PTEN inhibitor 1 M bpV(phen).
