Peptide DR8 analogs alleviate pulmonary fibrosis via suppressing TGF-β1 mediated epithelial-mesenchymal transition and ERK1/2 pathway in vivo and in vitro

The Peptide DHα-(4-pentenyl)-ANPQIR-NH2 Exhibits Antifibrotic Activity in Multiple Pulmonary Fibrosis Models Induced by Particulate and Soluble Chemical Fibrogenic Agents

Interstitial lung diseases (ILDs) are a group of restrictive lung diseases characterized by interstitial inflammation and pulmonary fibrosis. The incidence of ILDs associated with exposure to multiple hazards such as inhaled particles, fibers, and ingested soluble chemicals is increasing yearly, and there are no ideal drugs currently available. Our previous research showed that the novel and low-toxicity peptide DHα-(4-pentenyl)-ANPQIR-NH2 (DR3penA) had a strong antifibrotic effect on a bleomycin-induced murine model. Based on the druggability of DR3penA, we sought to investigate its effects on respirable particulate silicon dioxide (SiO2)- and soluble chemical paraquat (PQ)-induced pulmonary fibrosis in this study by using western blot, quantitative reverse-transcription polymerase chain reaction (RT-qPCR), immunofluorescence, H&E and Masson staining, immunohistochemistry, and serum biochemical assays. The results showed that DR3penA alleviated the extent of fibrosis by inhibiting the expression of fibronectin and collagen I and suppressed oxidative stress and epithelial-mesenchymal transition (EMT) in vitro and in vivo. Further study revealed that DR3penA may mitigate pulmonary fibrosis by negatively regulating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway and mitogen-activated protein kinase (MAPK) pathway. Unexpectedly, through the conversion of drug bioavailability under different routes of administration, DR3penA exerted antifibrotic effects equivalent to those of the positive control drug pirfenidone (PFD) at lower doses. In summary, DR3penA may be a promising lead compound for various fibrotic ILDs. SIGNIFICANCE STATEMENT: Our study verified that DHα-(4-pentenyl)-ANPQIR-NH2 (DR3penA) exhibited positive antifibrotic activity in pulmonary fibrosis induced by silicon dioxide (SiO2) particles and soluble chemical paraquat (PQ) and demonstrated a low-dose advantage compared to the small-molecule drug pirfenidone (PFD). The peptide DR3penA can be further developed for the treatment of multiple fibrotic lung diseases.

Emerging delivery approaches for targeted pulmonary fibrosis treatment

Pulmonary fibrosis (PF) is a progressive, and life-threatening interstitial lung disease which causes scarring in the lung parenchyma and thereby affects architecture and functioning of lung. It is an irreversible damage to lung functioning which is related to epithelial cell injury, immense accumulation of immune cells and inflammatory cytokines, and irregular recruitment of extracellular matrix. The inflammatory cytokines trigger the differentiation of fibroblasts into activated fibroblasts, also known as myofibroblasts, which further increase the production and deposition of collagen at the injury sites in the lung. Despite the significant morbidity and mortality associated with PF, there is no available treatment that efficiently and effectively treats the disease by reversing their underlying pathologies. In recent years, many therapeutic regimens, for instance, rho kinase inhibitors, Smad signaling pathway inhibitors, p38, BCL-xL/ BCL-2 and JNK pathway inhibitors, have been found to be potent and effective in treating PF, in preclinical stages. However, due to non-selectivity and non-specificity, the therapeutic molecules also result in toxicity mediated severe side effects. Hence, this review demonstrates recent advances on PF pathology, mechanism and targets related to PF, development of various drug delivery systems based on small molecules, RNAs, oligonucleotides, peptides, antibodies, exosomes, and stem cells for the treatment of PF and the progress of various therapeutic treatments in clinical trials to advance PF treatment.

The novel peptide DR4penA attenuates the bleomycin- and paraquat-induced pulmonary fibrosis by suppressing the TGF-β/Smad signaling pathway

Pulmonary fibrosis (PF), which is caused by continuous alveolar epithelial cell injury and abnormal repair, is referred to as a difficult disease of the lung system by the World Health Organization due to its rapid progression, poor prognosis, and high mortality rate. However, there is still a lack of ideal therapeutic strategies. The peptide DR8 (DHNNPQIR-NH2 ), which is derived from rapeseed, exerted antifibrotic activity in the lung, liver, and kidney in our previous studies. By studying the structure-activity relationship and rational design, we introduced an unnatural hydrophobic amino acid (α-(4-pentenyl)-Ala) into DR8 and screened the novel peptide DR4penA (DHNα-(4-pentenyl)-APQIR-NH2 ), which had higher anti-PF activity, higher antioxidant activity and a longer half-life than DR8. Notably, DR4penA attenuated bleomycin- and paraquat-induced PF, and the anti-PF activity of DR4penA was equivalent to that of pirfenidone. Additionally, DR4penA suppressed the TGF-β/Smad pathway in TGF-β1-induced A549 cells and paraquat-induced rats. This study demonstrates that the novel peptide DR4penA is a potential candidate compound for PF therapy, and its antifibrotic activity in different preclinical models of PF provides a theoretical basis for further study.

Molecular pathogenesis of subretinal fibrosis in neovascular AMD focusing on epithelial-mesenchymal transformation of retinal pigment epithelium

Age-related macular degeneration (AMD) is a leading cause of vision loss among elderly people in developed countries. Neovascular AMD (nAMD) accounts for more than 90% of AMD-related vision loss. At present, intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) is widely used as the first-line therapy to decrease the choroidal and retinal neovascularizations, and thus to improve or maintain the visual acuity of the patients with nAMD. However, about 1/3 patients still progress to irreversible visual impairment due to subretinal fibrosis even with adequate anti-VEGF treatment. Extensive literatures support the critical role of epithelial-mesenchymal transformation (EMT) of retinal pigment epithelium (RPE) in the pathogenesis of subretinal fibrosis in nAMD, but the underlying mechanisms still remain largely unknown. This review summarized the molecular pathogenesis of subretinal fibrosis in nAMD, especially focusing on the transforming growth factor-β (TGF-β)-induced EMT pathways. It was also discussed how these pathways crosstalk and respond to signals from the microenvironment to mediate EMT and contribute to the progression of nAMD-related subretinal fibrosis. Targeting EMT signaling pathways might provide a promising and effective therapeutic strategy to treat subretinal fibrosis secondary to nAMD.

A novel and low-toxic peptide DR3penA alleviates pulmonary fibrosis by regulating the MAPK/miR-23b-5p/AQP5 signaling axis

Pulmonary fibrosis (PF) is a pathological change caused by repeated injuries and repair dysfunction of the alveolar epithelium. Our previous study revealed that the residues Asn3 and Asn4 of peptide DR8 (DHNNPQIR-NH₂) could be modified to improve stability and antifibrotic activity, and the unnatural hydrophobic amino acids α-(4-pentenyl)-Ala and d-Ala were considered in this study. DR3penA (DHα-(4-pentenyl)-ANPQIR-NH₂) was verified to have a longer half-life in serum and to significantly inhibit oxidative damage, epithelial-mesenchymal transition (EMT) and fibrogenesis in vitro and in vivo. Moreover, DR3penA has a dosage advantage over pirfenidone through the conversion of drug bioavailability under different routes of administration. A mechanistic study revealed that DR3penA increased the expression of aquaporin 5 (AQP5) by inhibiting the upregulation of miR-23b-5p and the mitogen-activated protein kinase (MAPK) pathway, indicating that DR3penA may alleviate PF by regulating MAPK/miR-23b-5p/AQP5. Safety evaluation showed that DR3penA is a peptide drug without obvious toxicity or acute side effects and has significantly improved safety compared to DR8. Thus, our findings suggest that DR3penA, as a novel and low-toxic peptide, has the potential to be a leading compound for PF therapy, which provides a foundation for the development of peptide drugs for fibrosis-related diseases.

Peptide mediated therapy in fibrosis: Mechanisms, advances and prospects

Fibrosis, a disease characterized by an excess accumulation of extracellular matrix components, could lead to organ failure and death, and is to blame for up to 45 % of all fatalities in developed nations. These disorders all share the common trait of an unchecked and increasing accumulation of fibrotic tissue in the affected organs, which leads to their malfunction and eventual failure, even if their underlying causes are highly diverse and, in some cases, remain unclear. Numerous studies have identified activated myofibroblasts as the common cellular elements ultimately responsible for the replacement of normal tissues with nonfunctional fibrotic tissue. The transforming growth factor-β pathway, for instance, plays a significant role in practically all kinds of fibrosis. However, there is no specific drug for the treatment of fibrosis, several medications with anti-hepatic fibrosis properties are still in the research and development stages. Peptide, which refers to a substance consisting of 2-50 amino acids, is characterized by structural diversity, low toxicity, biological activities, easy absorption, specific targeting, few side effects, and has been proven to be effective in anti-fibrosis. Here, we summarized various anti-fibrosis peptides in fibrosis including the liver, lungs, kidneys, and other organs. This review will provide a new insight into peptide mediated anti-fibrosis and is helpful to creation of antifibrotic medications.

Effect of Pheretima aspergillum on reducing fibrosis: A systematic review and meta-analysis

Background: Pheretima aspergillum (common name: Earthworm, Chinese name: dilong) has been used in traditional Chinese medicine for thousands of years. Recently, a few scientific studies have investigated the antifibrotic effects of Dilong extract (DE) and produced controversial results. We conducted a meta-analysis to make an informed decision on the antifibrotic effects of Dilong extract. Methods: The studies on antifibrotic effects of Dilong extract published until July 2022 in the scientific databases [PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), VIP database for Chinese Technical Periodicals, SinoMed and WanFang database] were reviewed. The RevMan 5.4.1 software was used for standardized mean difference (SMD) analysis. Two researchers independently reviewed all the studies, and their quality was assessed using the Cochrane risk of bias tool. Results: A total of 325 studies were found in the scientific databases; however, only 13 studies met the criteria for analysis. Dilong extract treatment was associated with antifibrotic effects via inhibiting the transforming growth factor beta 1 (TGF-β1, SMD = -3.16, 95% CI: -4.18, -2.14, p < .00001) and alpha-smooth muscle actin (α-SMA: SMD = -2.57, 95% CI: -3.47, -1.66, p < .00001). Conclusion: Dilong extract effectively reduces tissue fibrosis; thus, further scientific studies should be conducted to investigate and develop it for clinical use. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022357141.

The mechanism of triptolide in the treatment of connective tissue disease-related interstitial lung disease based on network pharmacology and molecular docking

BACKGROUND

Interstitial lung disease (ILD) is associated with substantial morbidity and mortality, which is one of the key systematic manifestations of connective tissue disease (CTD). Tripterygium wilfordii, known as Leigongteng in Chinese, has been applied to treat connective tissue disease-related interstitial lung disease (CTD-ILD) for many years. Triptolide is a key effective component from Tripterygium wilfordii. But the molecular mechanism of Triptolide for treating CTD-ILD is not yet clear.

METHODS

Gaining insight into the molecular mechanism of Triptolide intervention CTD-ILD, we used the method of network pharmacology. And then we conducted drug-target networks to analyse the potential protein targets between Triptolide and CTD-ILD. Finally, AutoDock Vina was selected for molecular docking.

RESULTS

By analysing the interaction genes between Triptolide and CTD-ILD, 242 genes were obtained. The top 10 targets of the highest enrichment scores were STAT3, AKT1, MAPK1, IL6, TP53, MAPK3, RELA, TNF, JUN, JAK2. GO and KEGG enrichment analysis exhibited that multiple signalling pathways were involved. PI3K-Akt, multiple virus infections, cancer signalling, chemokine, and apoptosis signalling pathway are the main pathways for Triptolide intervention CTD-ILD. And it is related to various biological processes such as inflammation, infection, cell apoptosis, and cancer. Molecular docking shows Triptolide can bind with its target protein in a good bond by intermolecular force.

CONCLUSIONS

This study preliminarily reveals the internal molecular mechanism of Triptolide interfere with CTD-ILD through multiple targets, multiple access, validated through molecular docking.KEY MESSAGESTriptolide intervention CTD-ILD, which are related to various biological processes such as inflammation, infection, cell apoptosis, and cancer.PI3K-Akt, multiple virus infections, and apoptosis signalling pathway are the main pathways for Triptolide intervention CTD-ILD.Triptolide can bind with related target protein in a good bond by Intermolecular force, exhibiting a good docking activity.

Therapeutic potential for targeting Annexin A1 in fibrotic diseases

Annexin A1, a well-known endogenous anti-inflammatory mediator, plays a critical role in a variety of pathological processes. Fibrosis is described by a failure of tissue regeneration and contributes to the development of many diseases. Accumulating evidence supports that Annexin A1 participates in the progression of tissue fibrosis. However, the fundamental mechanisms by which Annexin A1 regulates fibrosis remain elusive, and even the functions of Annexin A1 in fibrotic diseases are still paradoxical. This review focuses on the roles of Annexin A1 in the development of fibrosis of lung, liver, heart, and other tissues, with emphasis on the therapy potential of Annexin A1 in fibrosis, and presents future research interests and directions in fibrotic diseases.