thymosin and Pulmonary-Fibrosis

Inflammation plays a critical role in the progression of pulmonary fibrosis. Thymosin β4 (Tβ4) has antioxidant, anti-inflammatory, and antifibrotic effects. Although the potent protective role of Tβ4 in bleomycin-induced pulmonary fibrosis has been validated, the underlying mechanism is not clear; moreover, the influence of Tβ4 on lipopolysaccharide (LPS)-induced lung injury/fibrosis has not been reported. Expression of Tβ4 in fibrotic lung tissues was assessed by real-time quantitative reverse-transcription PCR (rt-PCR), immunohistochemistry (IHC), and western blotting. The effects of intraperitoneal adeno-associated virus-Tβ4 (AAV-Tβ4) on LPS-induced lung injury and fibrosis were observed through the evaluation of collagen deposition and α-smooth muscle actin (SMA) expression. In vitro tests with HPAEpiC and HLF-1 cells were performed to confirm the effects of Tβ4. In this study, we evaluated the role of Tβ4 in pulmonary fibrosis and explored the possible underlying mechanisms. Tβ4 was markedly upregulated in human or mouse fibrotic lung tissues. AAV-Tβ4 markedly alleviated LPS-induced oxidative damage, lung injury, inflammation, and fibrosis in mice. Our in vitro experiments also showed that LPS inhibited mitophagy and promoted inflammation via oxidative stress in HPAEpiC, and Tβ4 significantly attenuated LPS-induced mitophagy inhibition, inflammasome activation, and transforming growth factor-β (TGF)-β1-induced epithelial-mesenchymal transition (EMT) in HPAEpiC. Moreover, Tβ4 suppressed the proliferation and attenuated the TGF-β1-induced activation of HLF-1 cells. In conclusion, Tβ4 alleviates LPS-induced lung injury, inflammation, and subsequent fibrosis in mice, suggesting that Tβ4 has a protective role in the pathogenesis of pulmonary fibrosis. Tβ4 is involved in attenuating oxidative injury, promoting mitophagy, and alleviating inflammation and fibrosis. Modulation of Tβ4 might be a novel strategy for treating pulmonary fibrosis.

Topics: Animals; Humans; Inflammation; Lipopolysaccharides; Male; Mice; Mice, Inbred ICR; Mitophagy; Oxidative Stress; Pulmonary Fibrosis; Thymosin

Thymosin β4 (Tβ4) and its amino-terminal fragment comprising N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) have been reported to act as anti-inflammatory and anti-fibrotic agents in vitro and in vivo. In recent papers, we have shown that Tβ4 exerts a widely protective role in mice treated with bleomycin, and in particular, we have demonstrated its inhibitory effects on both inflammation and early fibrosis.. In this study, the putative anti-proliferative and anti-fibrogenic effects of Tβ4 and Ac-SDKP were evaluated in vitro. In addition, the effects of Tβ4 up to 21 days were evaluated in the bleomycin mouse model of lung fibrosis.. We utilized both control and TGF-β-stimulated primary human lung fibroblasts isolated from both idiopathic pulmonary fibrosis (IPF) and control tissues. The in vivo effects of Tβ4 were assessed in CD1 mice treated with bleomycin.. In the in vitro experiments, we observed significant anti-proliferative effects of Ac-SDKP in IPF fibroblasts. In those cells, Ac-SDKP significantly inhibited TGF-β-induced α-SMA and collagen expression, hallmarks of fibroblast differentiation into myofibroblasts triggered by TGF-β. In vivo, despite its previously described protective role in mice treated with bleomycin at 7 days, Tβ4 failed to prevent fibrosis induced by the drug at 14 and 21 days.. We conclude that, compared to Tβ4, Ac-SDKP may have greater potential as an anti-fibrotic agent in the lung. Further in vivo experiments are warranted.

Topics: Animals; Anti-Inflammatory Agents; Bleomycin; Cells, Cultured; Disease Models, Animal; Fibroblasts; Humans; Lung; Male; Mice; Oligopeptides; Pneumonia; Protein Structure, Tertiary; Pulmonary Fibrosis; Thymosin; Transforming Growth Factor beta

Thymosin β4 (Tβ4) is a highly conserved peptide with immunomodulatory properties. In this research we investigated the effects of Tβ4 on the bleomycin-induced lung damage in CD-1 mice and the changes in the number of IL-17-producing cells as well as the IL-17 expression in the lung. Male CD-1 mice were treated with bleomycin (1mg/kg) in the absence or the presence of Tβ4 (6mg/kg delivered intra-peritoneally on the day of bleomycin treatment and for 2 additional doses). After sacrifice one week later, lung histology, measurement of collagen content of the lung, Broncho Alveolar Lavage Fluid (BALF) analysis, evaluation of IL17-producing cells in the blood as well as RT-PCR and IHC in the lung tissue were performed. As expected, bleomycin-induced inflammation and lung damage were substantially reduced by Tβ4 treatment in CD-1 mice, as shown by the significant reduction of (i) leukocytes in BALF, (ii) histological evidence of the lung damage, and (iii) total collagen content in the lung. Importantly, the bleomycin-induced increase in the number of IL17-producing cells in the blood was significantly blocked by Tβ4. Accordingly, IHC and RT-PCR results demonstrated that Tβ4 substantially inhibited bleomycin-induced IL-17 over-expression in the lung tissue. This is the first report showing that a decreased amount of IL17-producing cells and inhibited IL-17 expression in the lung with Tβ4 treatment correlate with its anti-inflammatory and anti-fibrotic effects.

Topics: Animals; Anti-Inflammatory Agents; Antibiotics, Antineoplastic; Bleomycin; Bronchoalveolar Lavage Fluid; Collagen; Disease Models, Animal; Inflammation; Interleukin-17; Leukocytes; Lung; Lung Injury; Male; Mice; Pulmonary Fibrosis; Random Allocation; Thymosin

Thymosin β4 (Tβ4) was recently found at high concentration in the bronchoalveolar lavage fluid (BALF) of scleroderma patients with lung involvement. It has been hypothesized that Tβ4 may exert a cyto-protective effect during lung injury because lower Tβ4 levels were associated with interstitial lung disease progression. Moreover, Tβ4 treatment prevented profibrotic gene expression in cardiac cells in vitro and in vivo.. In this study, we explored a putative Tβ4 protective role in lung damage by utilizing a well-known in vivo model of lung fibrosis. C57BL/6 mice were treated with bleomycin (BLEO, 1 mg/kg) in the absence or presence of Tβ4 (6 mg/kg delivered intraperitoneally on the day of BLEO treatment and for two additional doses). After sacrifice 1 week later, measurement of fluid and collagen content in the lung, BALF analysis, myeloperoxidase (MPO) activity assay, lung histology and IHC were performed.. Compared with BLEO-treated mice, BLEO-treated mice who received Tβ4 did not lose as much weight and had a higher survival rate. Moreover, BLEO-induced inflammation and lung damage were substantially reduced by Tβ4 treatment, as demonstrated by the significant reduction in oedema, total collagen content, lung infiltration by leucocytes, MPO activity in lung homogenates, and histological evidence of the ongoing lung fibrosis. Results of IHC show a strong reactivity for Tβ4 in the lung tissue of Tβ4-treated mice.. This is the first report that shows a Tβ4 protective role in lung toxicity associated with BLEO in a mouse model. Future studies are needed to assess its putative antifibrotic properties.

Topics: Animals; Antibiotics, Antineoplastic; Bleomycin; Bronchoalveolar Lavage Fluid; Collagen; Disease Models, Animal; Lung Injury; Male; Mice; Mice, Inbred C57BL; Peroxidase; Protective Agents; Pulmonary Edema; Pulmonary Fibrosis; Random Allocation; Thymosin; Weight Loss

Thymosin β4 (Tβ4) has been found to have several biological activities related to antiscarring and reduced fibrosis. For example, the anti-inflammatory properties of Tβ4 and its splice variant have been shown in the eye and skin. Moreover, Tβ4 treatment prevents profibrotic gene expression in cardiac and in hepatic cells in vitro and in vivo. In a recent study on scleroderma patients it was hypothesized that Tβ4 may exert a protective effect during human lung injury. In an ongoing study, we have explored the putative Tβ4 protective role in the lung context by utilizing a well-known in vivo model. We have observed significant protective effects of Tβ4 on bleomycin-induced lung damage, the main outcomes being the halting of the inflammatory process and a substantial reduction of histological evidence of lung injury.

Topics: Animals; Anti-Inflammatory Agents; Bleomycin; Inflammation; Lung; Mice; Pulmonary Fibrosis; Thymosin