Effects of Anoectochilus formosanus Hayata extract and glucocorticoid on lung maturation in preterm rats

Jinlian Xiaodu Decoction Protects against Bleomycin-Induced Pulmonary Fibrosis in Rats

Background

Jinlian Xiaodu Decoction (JXD) was reported to have anti-inflammatory and lung protection effects. This study aimed to explore the role and mechanism of JXD on bleomycin (BLM)-induced pulmonary fibrosis (PF).

Methods

The UHPLC-Q/TOF-MS system was applied to analyze JXD composition. The PF model was established by BLM intratracheal administration in Wistar rats. Subsequently, BLM-treated rats were intragastrically administered with dexamethasone (DXM, 1 g/kg/d) or JXD (3.5, 7 or 14 g/kg/d). Next, the lung coefficient was calculated; H&E, Masson, and TUNEL staining were used for lung morphological analysis and apoptosis assessment. Bronchoalveolar lavage fluid (BALF) biochemical analysis was conducted to count the inflammatory cell number. The expression of inflammatory factors mRNA in the lung tissue and BALF were measured by qRT-PCR. The content and activity of oxidative stress-related proteins were detected. The expression of PF-related, apoptosis-related, and TGF-β1 pathway-related protein were assessed by immunohistochemistry or Western blot.

Results

Twenty-six compounds were identified from JXD in both negative and positive ion modes. In BLM-induced rats, JXD reduced the lung coefficient and alleviated PF injury. JXD decreased inflammatory cell count and TNF-α, IL-1β, IL-6, and MCP-1 content. Meanwhile, JXD blunted BLM-induced oxidative stress and a high level of HYP. Furthermore, TUNEL analysis found that JXD inhibited cell apoptosis and increased Bcl-2/Bax ratio in BLM-induced lung. Moreover, JXD relieved the role of BLM on α-SMA, TGF-β1, collagen I, fibronectin, E-cadherin protein expression, and the phosphorylation of Smad2/3 in PF rat.

Conclusion

This study revealed the protective effect and possible element of JXD on BLM-caused PF.

Leucine Promotes Proliferation and Differentiation of Primary Preterm Rat Satellite Cells in Part through mTORC1 Signaling Pathway

Signaling through the mammalian target of rapamycin (mTOR) in response to leucine modulates many cellular and developmental processes. However, in the context of satellite cell proliferation and differentiation, the role of leucine and mTORC1 is less known. This study investigates the role of leucine in the process of proliferation and differentiation of primary preterm rat satellite cells, and the relationship with mammalian target of rapamycin complex 1 (mTORC1) activation. Dissociation of primary satellite cells occurred with type I collagenase and trypsin, and purification, via different speed adherence methods. Satellite cells with positive expression of Desmin were treated with leucine and rapamycin. We observed that leucine promoted proliferation and differentiation of primary satellite cells and increased the phosphorylation of mTOR. Rapamycin inhibited proliferation and differentiation, as well as decreased the phosphorylation level of mTOR. Furthermore, leucine increased the expression of MyoD and myogenin while the protein level of MyoD decreased due to rapamycin. However, myogenin expressed no affect by rapamycin. In conclusion, leucine may up-regulate the activation of mTORC1 to promote proliferation and differentiation of primary preterm rat satellite cells. We have shown that leucine promoted the differentiation of myotubes in part through the mTORC1-MyoD signal pathway.