osi-027 and Fibrosis

To investigate the effect and significance of mammalian target of rapamycin (mTOR) inhibitors on the expression of α-SMA in lung injury induced by high volume fraction of inspired oxygen (hyperoxygen) in SD rat pups.. Seventy-two Sprague-Dawley rat pups (age: 3 weeks) were randomly divided into air + saline, hyperoxia + saline, hyperoxia + OSI-027, and hyperoxia + rapamycin groups. Animal models were constructed (n = 18). Hyperoxia was induced by continuous administration of 90% oxygen. Normal saline, OSI-027, and rapamycin are administered by intraperitoneal injection on 1d, 3d, 6d, 8d, 10d, 13d of the observation period, respectively. Following assessments were made on the 3rd, 7th, and 14th day of modeling: pathological changes in lung tissues, lung injury score, Western Blot to assess the distribution and expressions of mTOR, pS6K1, and α-SMA protein in lung tissues.. In terms of time factors, the protein expressions of mTOR, pS6K1, and α-SMA increased with time. Except for the air group, the lung injury scores of the other groups increased with time, In terms of grouping factors, lung injury score in the air group was significantly lower than that in the other groups. In the hyperoxia group, the protein expressions of mTOR, PS6K1, and α-SMA were significantly higher than those in the other groups. The lung injury score in the hyperoxia group was significantly higher than that in the other groups. The lung injury score in the hyperoxia OSI group was significantly lower than that in the hyperoxia rapamycin group.. In hyperoxia lung injury, inhibiting the activation of mTOR signaling pathway can effectively reduce the expression of α-SMA; however, only mTORC1/2 dual inhibitor OSI-027 exhibited an anti-proliferative effect, and alleviated hyperoxia-induced lung injury and fibrosis in SD rat pups.

Topics: Actins; Animals; Female; Fibrosis; Hyperoxia; Imidazoles; Lung; Lung Injury; Male; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Rats; Rats, Sprague-Dawley; Ribosomal Protein S6 Kinases; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Triazines

TGFβ1 and mTOR are considered to play important roles in fibrotic diseases. Rapamycin has been reported to inhibit urethral stricture formation in a rabbit model of urethral fibrosis.. To evaluate if dual mTOR inhibitor has a superior efficacy compared with rapamycin on inhibiting cell proliferation and collagen expression in human urethral scar fibroblasts (HUSFs).. We established HUSF cultures from fresh surgical specimen. The HUSFs were identified with typical fibroblast markers using immunofluorescence. Then we examined the effect of TGFβ1 on HUSFs using Cell Counting Kit-8 and Western blot. The inhibiting effects of OSI-027 (a dual mTOR inhibitor) on cell proliferation and collagen expression in TGFβ1-induced HUSFs were compared with rapamycin using Cell Counting Kit-8, Western blot, and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR).. HUSFs were stained positive for vimentin, collagen I, and collagen III. TGFβ1 had no effect on cell proliferation but increased collagen I and collagen III expressions in HUSFs. OSI-027 was more effective inhibiting cell proliferation and collagen expression compared with rapamycin in TGFβ1-induced HUSFs. OSI-027 played a more important role in inhibiting TGFβ1-induced mTOR pathway and phosphorylation of Smad2 compared with rapamycin in HUSFs.. OSI-027 can inhibit the pro-fibrotic effects of TGFβ1 significantly compared with rapamycin in HUSFs. These findings may provide a new therapy in the adjunctive treatment of urethral stricture disease.

Topics: Cell Proliferation; Cells, Cultured; Cicatrix; Collagen Type I; Collagen Type I, alpha 1 Chain; Collagen Type III; Dose-Response Relationship, Drug; Fibroblasts; Fibrosis; Humans; Imidazoles; Phosphorylation; Primary Cell Culture; Protein Kinase Inhibitors; Signal Transduction; Sirolimus; Smad2 Protein; Time Factors; TOR Serine-Threonine Kinases; Transforming Growth Factor beta1; Triazines; Urethra; Vimentin

Topics: Biomarkers; Biopsy, Needle; Cells, Cultured; Fibroblasts; Fibrosis; Humans; Imidazoles; Immunohistochemistry; Molecular Targeted Therapy; Phosphorylation; Polymerase Chain Reaction; Scleroderma, Diffuse; Sensitivity and Specificity; Sirolimus; Smad2 Protein; TOR Serine-Threonine Kinases; Transforming Growth Factor beta; Triazines