Local administration of liposomal-based Srpx2 gene therapy reverses pulmonary fibrosis by blockading fibroblast-to-myofibroblast transition

Abstract

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive fatal interstitial lung disease characterized by abnormal transition and proliferation of fibroblasts. The uncontrolled transition of fibroblasts, commonly known as myofibroblasts, are the principal source of the enormous extracellular matrix (ECM) depositing in lung parenchyma, leading to gradual failure of gas exchange and mortality of the patients. However, up to now, rare effective therapeutic strategies have been developed to blockade fibroblast-to-myofibroblast transition (FMT) in IPF. Method: We illustrated that the lungs originated from IPF patients and mice with pulmonary fibrosis are characterized by the overexpression of sushi-repeat-containing protein, X-linked 2 (SRPX2). Further functionality studies identified the pivotal role of SRPX2 in FMT. Mechanistically, SRPX2 was involved in a TGFβR1/SMAD3/SRPX2/AP1/SMAD7 positive feedback loop. Specifically, SRPX2 was upregulated by TGF-β1 in a TGFβR1/SMAD3-dependent manner, after which SRPX2 in turn repressed the expression of AP1, subsequently minimized SMAD7 expression, through which it reduced the formation of inhibitory complex with TGFβR1 and enhanced SMAD signaling pathway to promote FMT and exacerbate pulmonary fibrosis. Notably, intratracheal administration of siRNA-loaded liposomes could effectively suppress the expression of Srpx2 in the lung and remarkably protect mice against BLM-induced pulmonary fibrosis, concomitant with a significant reduction of FMT. Results: Accordingly, these data indicate that Srpx2 plays an essential role in the pathogenesis of pulmonary fibrosis and suggests the strategy aiming at silencing Srpx2 could be a promising therapeutic approach against pulmonary fibrosis in clinical settings.

Tartrate-resistant acid phosphatase 5 promotes pulmonary fibrosis by modulating β-catenin signaling

“…Given that until now, no effective therapies to halt the progression of IPF have been available, we assessed the efficacy of targeting Acp5 in mice with fibrosis induced by BLM. Previous studies have established liposomes as drug carriers for inhalation owing to their safety and ability to provide controlled drug release in the lung 43 , 44 . In 2018, the first siRNA loaded liposomes (patisiran) was approved by the FDA, which moved gene therapy from concept to clinical application 45 .…”

“…PHLFs were isolated from para-carcinoma lung tissues resected from NSCLC patients, and PMLFs were isolated from the lung tissues of Acp5 −/− or WT mice 44 . Briefly, fibroblasts were generated by mincing lung tissue into submillimeter-sized pieces, plated evenly in 100 mm plates containing 2 ml of medium, which was changed after 24 h. Cells were cultured in DMEM containing 10% fetal bovine serum (FBS) and penicillin/streptomycin at 37 °C and tested for mycoplasma regularly.…”

“…DiR-labelled liposomes were constructed as previous reported 44 , and then, the prepared liposomes were intratracheal injection into the mice after 14 days of BLM induction. Subsequently, the mice were anesthetized with isoflurane (Sigma-Aldrich, St. Louis, MO, USA) and photoed at different time points (0 h, 1d, 3d, 6d) by an in vivo imaging system (IVIS Lumina XR, SI Imaging, AZ, USA) (excitation: 745 nm, emission: 830 nm).…”

Dihydromyricetin Alleviates Pulmonary Fibrosis by Regulating Abnormal Fibroblasts Through the STAT3/p-STAT3/GLUT1 Signaling Pathway

“…Although pirfenidone and nintedanib have been approved for the treatment of IPF, the outcomes of IPF patients are still not optimistic, and new treatments are urgently needed ( Caminati et al, 2019 ). As traditional Chinese medicine has attracted increasing attention, studies have illustrated that some herbal extracts have antifibrotic effects by suppressing the inflammation and oxidative stress induced by cytokines such as IL-6 and TGF- β 1 ( Wang et al, 2020 ; Wang Z. et al, 2021 ), but few of these medicines have been proven effective in clinical IPF patients. In our study, we isolated IPF-HLFs from the lung tissues of IPF patients, and DHM effectively regulated the differentiation, migration, and proliferation of IPF-HLFs.…”

“…After incubation, the slide was washed three times with PBS and then incubated with HRP- or 488-conjugated anti-mouse antibody and Alexa Fluor 594-conjugated anti-rabbit antibody (ZSGB-BIO, ZF-0512/0516, 1:400) for 1 h at room temperature. The slide was finally embedded with 4,6-diamino-2-phenylindole (DAPI) and analyzed under a fluorescence microscope ( Wang Y. et al, 2021 ).…”