Idiopathic Pulmonary Fibrosis: Current Status, Recent Progress, and Emerging Targets

The application and prospects of drug delivery systems in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease primarily affecting elderly individuals aged >65 years and has a poor prognosis. No effective treatment is currently available for IPF. The two antipulmonary fibrosis drugs nintedanib and pirfenidone approved by the FDA in the United States have somewhat decelerated IPF progression. However, the side effects of these drugs can lead to poor patient tolerance and compliance with the medications. Researchers have recently developed various methods for IPF treatment, such as gene silencing and pathway inhibitors, which hold great promise in IPF treatment. Nevertheless, the nonselectivity and nonspecificity of drugs often affect their efficacies. Drug delivery systems (DDS) are crucial for delivering drugs to specific target tissues or cells, thereby minimizing potential side effects, enhancing drug bioavailability, and reducing lung deposition. This review comprehensively summarizes the current state of DDS and various delivery strategies for IPF treatment (e.g., nano-delivery, hydrogel delivery, and biological carrier delivery) to completely expound the delivery mechanisms of different drug delivery carriers. Subsequently, the advantages and disadvantages of different DDS are fully discussed. Finally, the challenges and difficulties associated with the use of different DDS are addressed so as to accelerate their rapid clinical translation.

Smoking and Idiopathic Pulmonary Fibrosis: A Meta-analysis

INTRODUCTION

In this study, we aimed to systematically explore the relationship between smoking and idiopathic pulmonary fibrosis (IPF).

AIMS AND METHODS

The PubMed, Web of Science, and Embase databases were searched to systematically identify eligible studies. The Newcastle‒Ottawa Quality Assessment Scale (NOS) was used to evaluate the quality of the selected studies. The pooled odds ratio (OR) and survival hazard ratio (HR) were calculated with a random effects model using Stata 16.0 software.

RESULTS

Thirty studies were enrolled. All of the included studies were considered to have intermediate or high quality. Nine studies were suitable for meta-analysis of ORs, and 21 studies were suitable for meta-analysis of survival HR. The pooled analysis revealed a significant difference in the risk of IPF between the smoking group and the never-smoking group (OR 1.71, 95% CI: 1.27 to 2.30, p < .001), indicating that smoking is a risk factor for IPF. When analyzing pooled survival HRs, never smoking was compared to former smoking or current smoking. Former smoking was shown to be a poor prognostic factor for IPF (HR 1.43, 95% CI: 1.18 to 1.74, p < .001), but current smoking was not a significant factor.

CONCLUSIONS

Our results indicated that smoking is a risk factor for IPF patients.

IMPLICATIONS

In this study, we mainly concluded that smoking is a risk factor for IPF and that former smoking is a poor prognostic factor for IPF. To the best of our knowledge, this is the first meta-analysis report focusing on the association between smoking per se and IPF. Through our current study, we hope to further raise awareness of the relationship between smoking and IPF.

Causal relationship between circulating glutamine levels and idiopathic pulmonary fibrosis: a two-sample mendelian randomization study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive and debilitating respiratory disease with a median survival of less than 5 years. In recent years, glutamine has been reported to be involved in the regulation of collagen deposition and cell proliferation in fibroblasts, thereby influencing the progression of IPF. However, the relationships between glutamine and the incidence, progression, and treatment response of IPF remain unclear. Our study aimed to investigate the relationship between circulating glutamine levels and IPF, as well as its potential as a therapeutic target.

METHODS

We performed a comprehensive Mendelian Randomization (MR) analysis using the most recent genome-wide association study summary-level data. A total of 32 single nucleotide polymorphisms significantly correlated to glutamine levels were identified as instrumental variables. Eight MR analysis methods, including inverse variance weighted, MR-Egger, weighted median, weighted mode, constrained maximum likelihood, contamination mixture, robust adjusted profile score, and debiased inverse-variance weighted method, were used to assess the relationship between glutamine levels with IPF.

RESULTS

The inverse variance weighted analysis revealed a significant inverse correlation between glutamine levels and IPF risk (Odds Ratio = 0.750; 95% Confidence Interval : 0.592-0.951; P = 0.017). Sensitivity analyses, including MR-Egger regression and MR-PRESSO global test, confirmed the robustness of our findings, with no evidence of horizontal pleiotropy or heterogeneity.

CONCLUSION

Our study provides novel evidence for a causal relationship between lower circulating glutamine levels and increased risk of IPF. This finding may contribute to the early identification of high-risk individuals for IPF, disease monitoring, and development of targeted therapeutic strategies.

Therapeutic effects of flavonoids on pulmonary fibrosis: A preclinical meta-analysis

BACKGROUND

The efficacy of flavonoid supplementation in animal models of pulmonary fibrosis has been demonstrated.

PURPOSE

We conducted a systematic review and meta-analysis to evaluate the efficacy and underlying mechanisms of flavonoids in animal models of bleomycin-induced pulmonary fibrosis.

STUDY DESIGN

Relevant studies (n = 45) were identified from English- and Chinese-language databases from the inception of the database until October 2023.

METHODS

Methodological quality was evaluated using the SYRCLE risk of bias tool. Statistical analyses were conducted using RevMan 5.3 and Stata 17.0. Lung inflammation and fibrosis score were the primary outcome indicators.

RESULTS

Flavonoids can alleviate pathological changes in the lungs. The beneficial effects of flavonoids on pulmonary fibrosis likely relate to their inhibition of inflammatory responses, restoration of oxidative and antioxidant homeostasis, and regulation of fibroblast proliferation, migration, and activation by transforming growth factor β1/mothers against the decapentaplegic homologue/AMP-activated protein kinase (TGF-β1/Smad3/AMPK), inhibitor kappa B alpha/nuclear factor-kappa B (IκBα/NF-κB), phosphatidylinositol 3-kinase (PI3K)/AKT, interleukin 6/signal transducer/activator of transcription 3 (IL6/STAT3), and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathways.

CONCLUSION

Flavonoids are potential candidate compounds for the prevention and treatment of pulmonary fibrosis. However, extensive preclinical research is necessary to confirm the antifibrotic properties of natural flavonoids.

Pd-Catalyzed Enantioselective Three-Component Carboamination of 1,3-Cyclohexadiene

Asymmetric Pd-catalyzed three-component carboamination reactions of dienes to construct chiral cyclohexenylamines, which are of great importance in many fields of chemistry, have remained largely unexplored. Here, we demonstrate a highly enantio- and regioselective Pd/Ming-Phos-catalyzed carboamination reactions of 1,3-cyclohexadiene with readily available aryl iodides and anilines for facile access to diverse valuable chiral cyclohexenylamines. The process shows excellent functional group tolerance, easy scalability, and mild conditions. Moreover, mechanistic studies suggest that this reaction has a first-order dependence on the concentration of the palladium catalyst and aniline.

Therapeutic Strategies for Idiopathic Pulmonary Fibrosis - Thriving Present and Promising Tomorrow

Idiopathic pulmonary fibrosis (IPF) is a continuous, progressive, and lethal age-related respiratory disease. It is characterized by condensed and rigid lung tissue, which leads to a decline in the normal functioning of the lungs. The pathophysiology of IPF has still not been completely elucidated, so current strategies are lagging behind with respect to improving the condition of patients with IPF and increasing their survival rate. The desire for a better understanding of the pathobiology of IPF and its early detection has led to the identification of various biomarkers associated with IPF. The use of drugs such as pirfenidone and nintedanib as a safe and effective treatment alternative have marked a new chapter in the treatment of IPF. However, nonpharmacological therapies, involving long-term oxygen therapy, transplantation of the lungs, pulmonary rehabilitation, ventilation, and palliative care for cough and dyspnea, are still considered to be beneficial as supplementary methods for IPF therapy. A major risk factor for IPF is aging, with associated hallmarks such as telomere attrition, senescence, epigenetic drift, stem cell exhaustion, loss of proteostasis, and mitochondrial dysfunction. These are promising earmarks for the development of potential therapy for the disease. In this review, we have discussed current and emerging novel therapeutic strategies for IPF, especially for targets associated with age-related mechanisms.

Anti-pulmonary fibrosis activity analysis of methyl rosmarinate obtained from Salvia castanea Diels f. tomentosa Stib. using a scalable process

Pulmonary fibrosis is a progressive, irreversible, chronic interstitial lung disease associated with high morbidity and mortality rates. Current clinical drugs, while effective, do not reverse or cure pulmonary fibrosis and have major side effects, there are urgent needs to develop new anti-pulmonary fibrosis medicine, and corresponding industrially scalable process as well. Salvia castanea Diels f. tomentosa Stib., a unique herb in Nyingchi, Xizang, China, is a variant of S. castanea. and its main active ingredient is rosmarinic acid (RA), which can be used to prepare methyl rosmarinate (MR) with greater drug potential. This study presented an industrially scalable process for the preparation of MR, which includes steps such as polyamide resin chromatography, crystallization and esterification, using S. castanea Diels f. tomentosa Stib. as the starting material and the structure of the product was verified by NMR technology. The anti-pulmonary fibrosis effects of MR were further investigated in vivo and in vitro. Results showed that this process can easily obtain high-purity RA and MR, and MR attenuated bleomycin-induced pulmonary fibrosis in mice. In vitro, MR could effectively inhibit TGF-β1-induced proliferation and migration of mouse fibroblasts L929 cells, promote cell apoptosis, and decrease extracellular matrix accumulation thereby suppressing progressive pulmonary fibrosis. The anti-fibrosis effect of MR was stronger than that of the prodrug RA. Further study confirmed that MR could retard pulmonary fibrosis by down-regulating the phosphorylation of the TGF-β1/Smad and MAPK signaling pathways. These results suggest that MR has potential therapeutic implications for pulmonary fibrosis, and the establishment of this scalable preparation technology ensures the development of MR as a new anti-pulmonary fibrosis medicine.

Structural Modification and Optimisation of Hyperoside Oriented to Inhibit TGF-β-Induced EMT Activity in Alveolar Epithelial Cells

Pulmonary fibrosis (PF) is a disease characterised by diffuse nonspecific alveolar inflammation with interstitial fibrosis, which clinically manifests as dyspnoea and a significant decline in lung function. Many studies have shown that the epithelial-mesenchymal transition (EMT) plays a pivotal role in the pathogenesis of pulmonary fibrosis. Based on our previous findings, hypericin (Hyp) can effectively inhibit the process of the EMT to attenuate lung fibrosis. Therefore, a series of hyperoside derivatives were synthesised via modifying the structure of hyperoside, and subsequently evaluated for A549 cytotoxicity. Among these, the pre-screening of eight derivatives inhibits the EMT. In this study, we evaluated the efficacy of Z6, the most promising hyperoside derivative, in reversing TGF-β1-induced EMTs and inhibiting the EMT-associated migration of A549 cells. After the treatment of A549 cells with Z6 for 48 h, RT-qPCR and Western blot results showed that Z6 inhibited TGF-β1-induced EMTs in epithelial cells by supressing morphological changes in A549 cells, up-regulating E-cadherin (p < 0.01, p < 0.001), and down-regulating Vimentin (p < 0.01, p < 0.001). This treatment significantly reduced the mobility of transforming growth factor β1 (TGF-β1)-stimulated cells (p < 0.001) as assessed by wound closure, while increasing the adhesion rate of A549 cells (p < 0.001). In conclusion, our results suggest that hyperoside derivatives, especially compound Z6, are promising as potential lead compounds for treating pulmonary fibrosis, and therefore deserve further investigation.

Qingfei Tongluo Mixture Attenuates Bleomycin-Induced Pulmonary Inflammation and Fibrosis through mTOR-Dependent Autophagy in Rats

As an interstitial fibrosis disease characterized by diffuse alveolitis and structural alveolar disorders, idiopathic pulmonary fibrosis (IPF) has high lethality but lacks limited therapeutic drugs. A hospital preparation used for the treatment of viral pneumonia, Qingfei Tongluo mixture (QFTL), is rumored to have protective effects against inflammatory and respiratory disease. This study aims to confirm whether it has a therapeutic effect on bleomycin-induced IPF in rats and to elucidate its mechanism of action. Male SD rats were randomly divided into the following groups: control, model, CQ + QFTL (84 mg/kg chloroquine (CQ) + 3.64 g/kg QFTL), QFTL-L, M, H (3.64, 7.28, and 14.56 g/kg, respectively) and pirfenidone (PFD 420 mg/kg). After induction modeling and drug intervention, blood samples and lung tissue were collected for further detection. Body weight and lung coefficient were examined, combined with hematoxylin and eosin (H&E) and Masson staining to observe lung tissue lesions. The enzyme-linked immunosorbent assay (ELISA) and the hydroxyproline (HYP) assay kit were used to detect changes in proinflammatory factors (transforming growth factor-β (TGF-β), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β)) and HYP. Immunohistochemistry and Western blotting were performed to observe changes in proteins related to pulmonary fibrosis (α-smooth muscle actin (α-SMA) and matrix metalloproteinase 12 (MMP12)) and autophagy (P62 and mechanistic target of rapamycin (mTOR)). Treatment with QFTL significantly improved the adverse effects of bleomycin on body weight, lung coefficient, and pathological changes. Then, QFTL reduced bleomycin-induced increases in proinflammatory mediators and HYP. The expression changes of pulmonary fibrosis and autophagy marker proteins are attenuated by QFTL. Furthermore, the autophagy inhibitor CQ significantly reversed the downward trend in HYP levels and α-SMA protein expression, which QFTL improved in BLM-induced pulmonary fibrosis rats. In conclusion, QFTL could effectively attenuate bleomycin-induced inflammation and pulmonary fibrosis through mTOR-dependent autophagy in rats. Therefore, QFTL has the potential to be an alternative treatment for IPF in clinical practice.

Design, synthesis, and evaluation of pirfenidone-NSAIDs conjugates for the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal, chronic and progressive lung disease that threaten public health like many cancers. In this study, targeting the significant driving factor, inflammatory response, of the IPF, several conjugates of pirfenidone (PFD) with non-steroidal anti-inflammatory drugs (NSAIDs), along with their derivatives, were designed and synthesized to enhance the anti-IPF potency of PFD. Among these compounds, the (S)-ibuprofen-PFD conjugate 5b exhibited the most potent anti-proliferation activity against NIH3T3 cells, demonstrating up to a 343-fold improvement compared to PFD (IC50 = 0.04 mM vs IC50 = 13.72 mM). Notably, 5b exhibited superior activity in inhibiting the migration of macrophages induced by TGF-β compared to PFD. Additionally, 5b demonstrated significant suppression of TGF-β-induced migration of NIH3T3 cells and induction of apoptosis in NIH3T3 cells. Mechanistic studies revealed that 5b reduced the expression of collagen I and α-SMA by inhibiting the TGF-β/SMAD3 pathway. In a bleomycin-induced pulmonary fibrosis model, treatment with 5b (40 mg/kg/day, orally) exhibited a more pronounced effect on reducing the degree of histopathological changes in lung tissue and alleviating collagen deposition compared to PFD (100 mg/kg/day, orally). Moreover, 5b could block the expression of collagen I, α-SMA, fibronectin, and pro-inflammatory factors (IL-6, IFN-γ, and TNF-α) compared to PFD, while demonstrating low toxicity in vivo. These preliminary results indicated that the hybridization of PFD with NSAIDs represented an effective modification approach to improve the anti-IPF potency of PFD. Consequently, 5b emerged as a promising candidate for the further development of new anti-IPF agents.

Olfactory mucosa mesenchymal stem cells alleviate pulmonary fibrosis via the immunomodulation and reduction of inflammation

BACKGROUND

Pulmonary fibrosis (PF) is a progressive fibrosing interstitial pneumonia that leads to respiratory failure and other complications, which is ultimately fatal. Mesenchymal stem cells (MSCs) transplant is a promising strategy to solve this problem, while the procurement of MSCs from the patient for autotransplant remains a challenge.

METHODS

Here, we presented olfactory mucosa mesenchymal stem cells (OM-MSCs) from mouse turbinate and determined the preventing efficacy of allotransplant for PF. We demonstrated the antiinflammation and immunomodulatory effects of OM-MSCs. Flow cytometric analysis was used to verify the effect of OM-MSCs on monocyte-derived macrophage populations in the lung.

RESULTS

Administration of OM-MSCs reduces inflammation, attenuates the matrix metallopeptidase 13 (MMP13) expression level and restores the bleomycin (BLM)-induced pulmonary fibrosis by assessing the architecture of lung, collagen type I; (COL1A1), actin alpha 2, smooth muscle, aorta (ACTA2/α-SMA) and hydroxyproline. This therapeutic effect of OM-MSCs was related to the increase in the ratio of nonclassical monocytes to proinflammatory monocytes in the lung.

CONCLUSIONS

This study suggests that transplant of OM-MSCs represents an effective and safe treatment for PF.

Synthesis and structure-activity optimization of hydroxypyridinones against rhabdomyolysis-induced acute kidney injury

The important role of accumulated iron is well recognized in the pathophysiology of rhabdomyolysis-induced acute kidney injury (RM-AKI). Our previous work further confirmed the labile iron triggered iron-dependent ferroptosis thus leading to the renal failure. In view of this, a series of hydroxypyridinones (HOPOs) with excellent iron chelation capability have been designed and synthesized in this study. A lead compound 6k was identified with good ferroptosis inhibition (EC50 = 20 μM) and no obvious cytotoxicity (CC50 > 100 μM), indicating a good therapeutic window (safety index = CC50/EC50 > 5.00). Moreover, intraperitoneal treatment of 6k (10 mg/kg) displayed a superior protective effect than deferiprone (50 mg/kg) in glycerol-induced RM-AKI mice with alleviating kidney dysfunction and pathological injury, decreasing the renal iron level as well as downregulating the mRNA level of ferroptosis associated genes (Acls4 and Ptgs2). Also, 6k exhibited a good in vivo safety profile, even at single high dose up to 1 g/kg without inducing mortality or toxic symptoms. Importantly, 6k could significantly upregulate the protein hypoxia-inducible factor 1α, possibly involving HIF pathway against the ferroptosis. These results collectively highlighted that the strategy of iron chelation and downstream ferroptosis inhibition has a therapeutic potential against RM-AKI.

N-(2-Aminophenyl)-benzamide Inhibitors of Class I HDAC Enzymes with Antiproliferative and Antifibrotic Activity

Inhibitors of histone deacetylases (HDACs) have received special attention as novel anticancer agents. Among various types of synthetic inhibitors, benzamides constitute an important class, and one is an approved drug (chidamide). Here, we present a novel class of HDAC inhibitors containing the N-(2-aminophenyl)-benzamide functionality as the zinc-binding group linked to various cap groups, including the amino acids pyroglutamic acid and proline. We have identified benzamides that inhibit HADC1 and HDAC2 at nanomolar concentrations, with antiproliferative activity at micromolar concentrations against A549 and SF268 cancer cell lines. Docking studies shed light on the mode of binding of benzamide inhibitors to HDAC1, whereas cellular analysis revealed downregulated expression of EGFR mRNA and protein. Two benzamides were investigated in a mouse model of bleomycin-induced pulmonary fibrosis, and both showed efficacy on a preventative dosing schedule. N-(2-Aminophenyl)-benzamide inhibitors of class I HDACs might lead to new approaches for treating fibrotic disorders.

Synergistic Power of Piceatannol and/or Vitamin D in Bleomycin-Induced Pulmonary Fibrosis In Vivo: A Preliminary Study

Oxidative stress and epigenetic alterations, including the overexpression of all class I and II histone deacetylases (HDACs), particularly HDAC2 and HDAC4, have been identified as key molecular mechanisms driving pulmonary fibrosis. Treatment with piceatannol (PIC) or vitamin D (Vit D) has previously exhibited mitigating impacts in pulmonary fibrosis models. The present study investigated the effects of PIC, Vit D, or a combination (PIC-Vit D) on the expression of HDAC2, HDAC4, and transforming growth factor-beta (TGF-β) in the lungs; the phosphatidylinositide-3-kinase (PI3K)/AKT signaling pathway; and the antioxidant status of the lungs. The objective was to determine if the treatments had protective mechanisms against pulmonary fibrosis caused by bleomycin (BLM) in rats. Adult male albino rats were given a single intratracheal dosage of BLM (10 mg/kg) to induce pulmonary fibrosis. PIC (15 mg/kg/day, oral (p.o.)), Vit D (0.5 μg/kg/day, intraperitoneal (i.p.)), or PIC-Vit D (15 mg/kg/day, p.o. plus 0.5 μg/kg/day, i.p.) were given the day following BLM instillation and maintained for 14 days. The results showed that PIC, Vit D, and PIC-Vit D significantly improved the histopathological sections; downregulated the expression of HDAC2, HDAC4, and TGF-β in the lungs; inhibited the PI3K/AKT signaling pathway; decreased extracellular matrix (ECM) deposition including collagen type I and alpha smooth muscle actin (α-SMA); and increased the antioxidant capacity of the lungs by increasing the levels of glutathione (GSH) that had been reduced and decreasing the levels of malondialdehyde (MDA) compared with the BLM group at a p-value less than 0.05. The concomitant administration of PIC and Vit D had a synergistic impact that was greater than the impact of monotherapy with either PIC or Vit D. PIC, Vit D, and PIC-Vit D exhibited a notable protective effect through their antioxidant effects, modulation of the expression of HDAC2, HDAC4, and TGF-β in the lungs, and suppression of the PI3K/AKT signaling pathway.

New therapeutic approaches against pulmonary fibrosis

Pulmonary fibrosis is the end-stage change of a large class of lung diseases characterized by the proliferation of fibroblasts and the accumulation of a large amount of extracellular matrix, accompanied by inflammatory damage and tissue structure destruction, which also shows the normal alveolar tissue is damaged and then abnormally repaired resulting in structural abnormalities (scarring). Pulmonary fibrosis has a serious impact on the respiratory function of the human body, and the clinical manifestation is progressive dyspnea. The incidence of pulmonary fibrosis-related diseases is increasing year by year, and no curative drugs have appeared so far. Nevertheless, research on pulmonary fibrosis have also increased in recent years, but there are no breakthrough results. Pathological changes of pulmonary fibrosis appear in the lungs of patients with coronavirus disease 2019 (COVID-19) that have not yet ended, and whether to improve the condition of patients with COVID-19 by means of the anti-fibrosis therapy, which are the questions we need to address now. This review systematically sheds light on the current state of research on fibrosis from multiple perspectives, hoping to provide some references for design and optimization of subsequent drugs and the selection of anti-fibrosis treatment plans and strategies.

Ginsenoside Rg3 attenuates pulmonary fibrosis by inhibiting endothelial to mesenchymal transition

Pulmonary fibrosis (PF) is a progressive and chronic lung disease characterized by excessive extracellular matrix (ECM) deposition and fibroblast proliferation. Endothelial-to-mesenchymal transition (EndMT) serves as a source of fibroblasts and contributes to PF progression. Ginsenoside Rg3 (Rg3), a steroidal saponin extracted from ginseng, is known to have pharmacological effects on vascular diseases. We have previously demonstrated that Rg3 inhibits EndMT and prevents endothelial dysfunction. Thus, we hypothesized that Rg3 may be a potential therapeutic agent for PF-targeting EndMT. EndMT occurs in the lung tissue of a bleomycin-induced PF mouse model, which was confirmed by co-staining of endothelial and mesenchymal markers in the pulmonary vasculature and changes in the expression of these markers. Rg3 administration decreased EndMT and suppressed PF development. We also examined the effect of Rg3 in an in vitro EndMT model induced by co-treatment with TGF-β2 and IL-1β. Rg3 treatment alleviated the characteristics of EndMT such as spindle-shaped morphological changes, EndMT marker expression changes, Dil-Ac-LDL uptake and migratory properties. In addition, we demonstrated the mechanism by which Rg3 inhibits EndMT by regulating the Smad2/3 signaling pathway. Collectively, Rg3 can be a potential therapeutic agent for PF using the EndMT inhibition strategy, furthermore, it can be considered Rg3 as a therapeutic candidate for various EndMT-associated vascular diseases.

Amifostine attenuates bleomycin-induced pulmonary fibrosis in mice through inhibition of the PI3K/Akt/mTOR signaling pathway

Amifostine is a normal cell protection agent, not only used in the adjuvant therapy of lung cancer, ovarian cancer, breast cancer, nasopharyngeal cancer, bone tumor, digestive tract tumor, blood system tumor and other cancers in order to reduce the toxicity of chemotherapy drugs, and recent studies have reported that the drug can also reduce lung tissue damage in patients with pulmonary fibrosis, but its mechanism of action is not yet fully understood. In this study, we explored the potential therapeutic effects and molecular mechanisms of AMI on bleomycin (BLM)-induced pulmonary fibrosis in mice. A mouse model of pulmonary fibrosis was established using BLM. We then assessed histopathological changes, inflammatory factors, oxidative indicators, apoptosis, epithelial-mesenchymal transition, extracellular matrix changes, and levels of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway-related proteins in the BLM-treated mice to determine the effect of AMI treatment on these factors. BLM-treated mice had substantial lung inflammation and abnormal extracellular matrix deposition. Overall, treatment with AMI significantly improved BLM-induced lung injury and pulmonary fibrosis. More specifically, AMI alleviated BLM-induced oxidative stress, inflammation, alveolar cell apoptosis, epithelial-mesenchymal transition, and extracellular matrix deposition by regulating the PI3K/Akt/mTOR signaling pathway. This finding that AMI can alleviate pulmonary fibrosis in a mouse model by inhibiting activation of the PI3K/Akt/mTOR signaling pathway lays a foundation for potential future clinical application of this agent in patients with pulmonary fibrosis.

Network pharmacology and experiments in vivo and in vitro reveal that the Jia-Wei-Bu-Shen-Yi-Qi formula (JWBSYQF) and its active ingredient baicalein ameliorate BLM-induced lung fibrosis in mice via PI3K/Akt signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Jia-Wei-Bu-Shen-Yi-Qi formula (JWBSYQF), a classical traditional Chinese herbal formula consisting of five herbs, is used clinically in China to treat inflammatory lung diseases, including asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Its mechanism for treating asthma and COPD has been reported, however, how it works against IPF remains unclear.

RESEARCH PURPOSE

Our study aims to observe the therapeutic effect of JWBSYQF on pulmonary fibrosis and further identify the potential active ingredients and molecular pathways.

RESEARCH METHODS

In this study, we used a bleomycin-induced mouse model to investigate the therapeutic effect of JWBSYQF on pulmonary fibrosis. To further explore the potential effective ingredients and molecular pathways, we used the network pharmacology approach to construct a drug-ingredient-target network of JWBSYQF. Then, the common target set was established for JWBSYQF, fibroblast, and lung fibrosis. Analyses of the KEGG pathway, GO enrichment, and network topology were performed to identify key biological processes and molecular pathways for the common targets. Finally, a TGF-β-induced NIH/3T3 proliferation and activation model was used to validate the possible active ingredients and signaling pathways.

RESEARCH RESULTS

JWBSYQF reversed BLM-induced balf leukocyte levels, pulmonary inflammatory lesions and fibrotic collagen deposition in mice and reduced the levels of a-SMA, Col1a1 and TGF-β. A total of 86 active ingredients were identified, 12 of which were considered as potential effective ingredients, while only baicalein effectively improved TGF-β-induced proliferation and activation of NIH/3T3. KEGG results showed that PI3K/Akt signaling pathway may be the potential action mechanism, and Western Blot demonstrated that both JWBSYQF and baicalein downregulated the protein levels of p-PI3K and p-Akt. The molecular docking results suggested that baicalein may directly act on the catalytic and regulatory subunits of PI3K, and this a effect is stronger than direct binding to Akt1.

CONCLUSIONS

Our study revealed that baicalein may be the material basis for JWBSYQF in the treatment of pulmonary fibrosis, and the PI3K/Akt signaling pathway may be a common pathway of action for JWBSYQF and baicalein.

Baicalin/ambroxol hydrochloride combined dry powder inhalation formulation targeting lung delivery for treatment of idiopathic pulmonary fibrosis: fabrication, characterization, pharmacokinetics, and pharmacodynamics

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal lung disease caused by multiple factors. Currently, safe, and effective drugs for the treatment of IPF have been extremely scarce. Baicalin (BA) is used to treat pulmonary fibrosis, IPF, chronic obstructive pulmonary disease, and other lung diseases. Ambroxol hydrochloride (AH), a respiratory tract lubricant and expectorant, is often used to treat chronic respiratory diseases, such as bronchial asthma, emphysema, tuberculosis, and cough. The combination of BA and AH can relieve cough and phlegm, improve lung function, and potentially treat IPF and its symptoms. However, given the extremely low solubility of BA, its bioavailability for oral absorptions is also low. AH, on the other hand, has been associated with certain side effects, such as gastrointestinal tract and acute allergic reactions, which limit its applicability. Therefore, an efficient drug delivery system is urgently needed to address the mentioned problems. This study combined BA and AH as model drugs with L-leucine (L-leu) as the excipient to prepare BA/AH dry powder inhalations (BA/AH DPIs) using the co-spray drying method. We the performed modern pharmaceutical evaluation, which includes particle size, differential scanning calorimetry analysis, X-ray diffraction, scanning electron microscope, hygroscopicity, in vitro aerodynamic analysis, pharmacokinetics, and pharmacodynamics. Notably, BA/AH DPIs were found to be advantageous over BA and AH in treating IPF and had better efficacy in improving lung function than did the positive drug pirfenidone. The BA/AH DPI is a promising preparation for the treatment of IPF given its lung targeting, rapid efficacy, and high lung bioavailability.

Towards a Unified Approach in Autoimmune Fibrotic Signalling Pathways

Autoimmunity is a chronic process resulting in inflammation, tissue damage, and subsequent tissue remodelling and organ fibrosis. In contrast to acute inflammatory reactions, pathogenic fibrosis typically results from the chronic inflammatory reactions characterizing autoimmune diseases. Despite having obvious aetiological and clinical outcome distinctions, most chronic autoimmune fibrotic disorders have in common a persistent and sustained production of growth factors, proteolytic enzymes, angiogenic factors, and fibrogenic cytokines, which together stimulate the deposition of connective tissue elements or epithelial to mesenchymal transformation (EMT) that progressively remodels and destroys normal tissue architecture leading to organ failure. Despite its enormous impact on human health, there are currently no approved treatments that directly target the molecular mechanisms of fibrosis. The primary goal of this review is to discuss the most recent identified mechanisms of chronic autoimmune diseases characterized by a fibrotic evolution with the aim to identify possible common and unique mechanisms of fibrogenesis that might be exploited in the development of effective antifibrotic therapies.

Discovery of indoline-based derivatives as effective ROCK2 inhibitors for the potential new treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and devastating lung disease with a median survival of only 3-5 years. Due to the lack of effective therapy, IPF threatens human health. Recently, increasing reports have indicated that Rho-associated coiled-coil protein kinases (ROCKs) play important roles in the development of IPF and might represent a novel target for the treatment of IPF. Herein, a new series of selective ROCK2 inhibitors based on indoline were designed and synthesized. Structural modification resulted in optimized compound 9b with an IC₅₀ value of 6 nM against ROCK2 and the inhibition of collagen gel contraction. Cellular assays demonstrated that 9b could significantly suppress the expression of collagen I and α-SMA, and inhibited ROCK signaling pathway. Oral administration of compound 9b (10 mg/kg) exerted more significant anti-pulmonary fibrosis effects than nintedanib (100 mg/kg) and KD025 (100 mg/kg) in a bleomycin-induced IPF rat model, suggesting that 9b could serve as a potential lead compound for the treatment of IPF.

Inflammation-Associated Lung Tissue Remodeling and Fibrosis in Morphine-Dependent SIV-Infected Macaques

With the advent of antiretroviral therapy, improved survival of people with HIV (PWH) is accompanied with increased prevalence of HIV-associated comorbidities. Chronic lung anomalies are recognized as one of the most devastating sequelae in PWH. The limited available data describing the lung complications in PWH with a history of opioid abuse warrants more research to better define the course of disease pathogenesis. The current study was conducted to investigate the progression of lung tissue remodeling in a morphine (Mor)-exposed rhesus macaque model of SIV infection. Pathologic features of lung remodeling, including histopathologic changes, oxidative stress, inflammation, and proliferation of fibroblasts, were investigated in archival lung tissues of SIVmac-251/macaque model with or without Mor dependence. Lungs of Mor-exposed, SIV-infected macaques exhibited significant fibrotic changes and collagen deposition in the alveolar and the bronchiolar region. There was increased oxidative stress, profibrotic transforming growth factor-β, fibroblast proliferation and trans-differentiation, epithelial-mesenchymal transition, and matrix degradation in SIV-infected macaques, which was further exacerbated in the lungs of Mor-exposed macaques. Interestingly, there was decreased inflammation-associated remodeling in Mor-dependent SIV-infected macaques compared with SIV-infected macaques that did not receive Mor. Thus, the current findings suggest that SIV independently induces fibrotic changes in macaque lungs, which is further aggravated by Mor.

T cells in idiopathic pulmonary fibrosis: crucial but controversial

Idiopathic pulmonary fibrosis (IPF) has been extensively studied in recent decades due to its rising incidence and high mortality. Despite an abundance of research, the mechanisms, immune-associated mechanisms, of IPF are poorly understood. While defining immunopathogenic mechanisms as the primary pathogenesis is controversial, recent studies have verified the contribution of the immune system to the fibrotic progression of IPF. Extensive evidence has shown the potential role of T cells in fibrotic progression. In this review, we emphasize the features of T cells in IPF and highlight the controversial roles of different subtypes of T cells or even two distinct effects of one type of T-cell in diverse settings, and multiple chemokines and cell products are discussed. Furthermore, we discuss the potential development of treatments targeting the immune molecules of T cells and the feasibility of immune therapies for IPF in clinical practice.

Immune Mechanisms of Pulmonary Fibrosis with Bleomycin

Fibrosis and structural remodeling of the lung tissue can significantly impair lung function, often with fatal consequences. The etiology of pulmonary fibrosis (PF) is diverse and includes different triggers such as allergens, chemicals, radiation, and environmental particles. However, the cause of idiopathic PF (IPF), one of the most common forms of PF, remains unknown. Experimental models have been developed to study the mechanisms of PF, and the murine bleomycin (BLM) model has received the most attention. Epithelial injury, inflammation, epithelial-mesenchymal transition (EMT), myofibroblast activation, and repeated tissue injury are important initiators of fibrosis. In this review, we examined the common mechanisms of lung wound-healing responses after BLM-induced lung injury as well as the pathogenesis of the most common PF. A three-stage model of wound repair involving injury, inflammation, and repair is outlined. Dysregulation of one or more of these three phases has been reported in many cases of PF. We reviewed the literature investigating PF pathogenesis, and the role of cytokines, chemokines, growth factors, and matrix feeding in an animal model of BLM-induced PF.

Design, synthesis, and biological evaluation of BRD4 degraders

Epigenetic proteins are one of the important targets in the current research fields of cancer therapy. A family of bromodomain-containing (BRD) and extra terminal domain (BET) proteins act as epigenetic readers to regulate the expression of key oncogenes and anti-apoptotic proteins. Recently, although BET degraders based on PROTAC technology have achieved significant antitumor effects, the lack of selectivity for BET protein degradation has not been fully addressed. Herein, a series of small molecule BRD4 PROTACs were designed and synthesized. Most of the degraders were effective in inhibiting MM.1S and MV-4-11 cell lines, especially in MV-4-11. Among them, degrader 8b could induce the degradation of BRD4 and exhibited a time- and concentration-dependent depletion manner and there was a significant depletion of BRD4, laying a foundation for effectively treating leukemia and multiple myeloma. Moreover, 8b could also effectively prevent the activation of MRC5 cells by inducing the degradation of BRD4 protein, which preliminarily proves that the BRD4 degrader based on the PROTAC concept has great potential for the treatment of pulmonary fibrosis. Taken together, these findings laid a foundation for BRD4 degraders as an effective strategy for treating related diseases.

A qualitative exploration of people living with idiopathic pulmonary fibrosis experience of a virtual pulmonary rehabilitation programme

BACKGROUND

Pulmonary rehabilitation (PR) is recommended in the treatment of people with idiopathic pulmonary fibrosis (IPF). Little is known about the experiences of people with IPF of PR. Due to Covid-19 there has been a rapid shift of PR services to remote/virtual delivery.

OBJECTIVE

To explore people living with IPFs experience of a virtual PR (VPR) programme.

METHODS

All patients with a diagnosis of IPF in a stable phase of the disease were invited to participate in virtual PR: a 10 week exercise programme delivered twice-weekly for one hour. One-to-one semi- structured interviews were conducted within one week following the programme. All interviews were recorded, transcribed and analysed using Braun and Clarke thematic analysis by two independent assessors.

RESULTS

N=13 participants took part in the semi-structured interviews, mean (standard deviation (SD)) age 69.5(10.4) years; 7M:6F. Mean (SD) FEV1 2.6(0.3)L, FVC 2.9(0.4)L. Four key themes were identified: 1) The impact of VPR on health and outlook, (2) The reality of VPR, (3) Being active after VPR and (4) Living with IPF during the COVID-19 Pandemic. Participants reported high levels of enjoyment and engagement with the programme regardless of the health benefits experienced. Most participants expressed a desire for a longer programme. Participants expressed different levels of maintenance with exercise since finishing the programme, specific motivators and strategies for maintenance included lung transplant, the maintenance of benefits from the programme and social support. COVID-19 and the restrictions imposed had some negative impacts on some participants lives, engaging with PR helped overcome some of these.

CONCLUSION

Despite the progressive nature of IPF, all participants expressed high levels of enjoyment with the programme. Future research should explore strategies for maintenance post PR and the optimum duration of PR for people with IPF.

Identification of diagnostic gene biomarkers related to immune infiltration in patients with idiopathic pulmonary fibrosis based on bioinformatics strategies

Objective

The study aims to identify potential diagnostic markers of idiopathic pulmonary fibrosis (IPF) and analyze the significance of immune cell infiltration in this pathology.

Materials and methods

Download two publicly available gene expression profiles (GSE10667 and GSE24206 datasets) from the GEO database including 48 Idiopathic pulmonary fibrosis (IPF) samples and 21 human control samples and select for distinctly expressed genes (DEG) from them. Lasso regression model and support vector machine recursive feature elimination S,V,R,F analysis were used to check candidate biomarkers. The area under the subject's work characteristic curve (AUC) value is used to evaluate its recognition ability. The GSE53845 dataset (40 IPF patients and 8 controls) continue to validate the expression level and diagnostic value of biomarkers in IPF. Comprehensive analysis of immune infiltrated cells of IPF was performed using R software and immune cell infiltration estimation analysis tool- deconvolution algorithm (CIBERSORT).

Results

43 DEGs were identified in total. The identified DEGs mostly involve pneumonia, lung disease, collagen disease, obstructive pulmonary disease and other diseases. The activation of IL-17 signaling pathways, amoebic disease, interaction of viral proteins with cytokines and cytokine receptors, protein digestion and absorption, and flaccid hormone signaling pathways in IPF were different from the control group. The expression degree of CRTAC1, COL10A1, COMP, RPS4Y1, IGFL2, NECAB1, SCG5, SLC6A4, and SPP1 in IPF tissue were prominently higher than the normal group. Immune cell infiltration analysis showed that CRTAC1, COL10A1, COMP, IGFL2, NECAB1, SCG5, SLC6A4, and SPP1 were associated with monocytes, plasma cells, neutrophils, and regulatory (treg) T cells.

Conclusion

CRTAC1, COL10A1, COMP, IGFL2, NECAB1, SCG5, SLC6A4, and SPP1 can be used as diagnostic markers for IPF, providing new ideas for the future study of IPF occurrence and molecular mechanisms.

Stabil idiyopatik pulmoner fibrozde hastalik şiddeti ve prognostik belirteçler ile matriks metallaproteinaz düzeyleri arasindaki ilişki

Purpose: Blood-derived biomarkers have been extensively considered as possible prognostic indicators in idiopathic pulmonary fibrosis (IPF) recently. In order to assess the value of circulating biomarkers in common IPF clinical practice, the study intends to draw conclusions regarding the link between disease severity, prognostic indicators, and serum matrix metalloproteinase in patients with stable idiopathic pulmonary fibrosis. Materials and Methods: The study comprised 22 people with an IPF diagnosis that had been verified by a multidisciplinary approach. The sociodemographic details, clinical and radiologic symptoms, pulmonary function tests and the Gender-Age-Physiology (GAP) score were noted. ELISA has been used to research serum MMP concentrations. Results: There is no statistically significant correlation between the Matrix Metalloproteinase (MMP) 2, MMP 7, MMP 9, and MMP13 and the GAP index and, pulmonary function tests, or disease severity. GAP score was found to be higher in stage 3 in patients with severe disease, in stage 2 in patients with moderate disease, and in stage 1 in patients with mild disease. Conclusion: There are consistent findings in the literature, despite the fact that the association between MMP and IPF prognostic markers, pulmonary function tests, and disease severity could not be seen in this investigation. However, because they could open the door to a cutting-edge treatment strategy, these indicators should be investigated prospectively in larger series.

Targeting the LPA1 signalling pathway for fibrosis therapy: a patent review (2010-present)

INTRODUCTION

Fibrosis is a disease that damages organs and even causes death. Because of the complicated pathogenesis, the development of drugs for fibrosis is challenging. In the lysophosphatidic acid receptor type 1 (LPA1) signalling pathway, LPA1 and its downstream Rho-associated coiled-coil forming protein kinase (ROCK) are related to the process of fibrosis. Targeting LPA1 signalling pathway is a potential strategy for the treatment of fibrosis.

AREA COVERED

This review describes the process of fibrosis mediated by the LPA1 signalling pathway and then summarizes LPA1 antagonist patents reported since 2010 and ROCK inhibitor patents since 2017 according to their scaffolds based on the Cortellis Drug Discovery Intelligence database. Information on LPA1 antagonists entering clinical trials is integrated.

EXPERT OPINION

Over the past decade, a large number of antagonists targeting the LPA1 signalling pathway have been patented for fibrosis therapy. A limited number of compounds have entered clinical trials. Different companies and research groups have used different scaffolds when designing compounds for fibrosis therapy. Therefore, LPA1 and ROCK are competitive targets for the development of new therapies for fibrosis to provide a potential treatment method for fibrosis in the future.

Granulocyte colony-stimulating factor in bronchoalveolar lavage fluid is a potential biomarker for prognostic prediction of idiopathic pulmonary fibrosis

BACKGROUND/AIMS

Neutrophilia is frequently observed in bronchoalveolar lavage fluid (BALF) of idiopathic pulmonary fibrosis (IPF) patients. Granulocyte colony-stimulating factor (G-CSF) is a potent neutrophil-activating glycoprotein. However, the clinical implications of G-CSF remain poorly understood.in patients with IPF. Therefore, we evaluated the relationship between the G-CSF concentration in BALF and the progression of fibrosis, including in terms of the decline in lung function and long-term survival rate.

METHODS

G-CSF concentrations were measured in BALF using enzyme-linked immunosorbent assay (ELISA). The survival rate was estimated using Kaplan-Meier survival analyses.

RESULTS

G-CSF protein levels were significantly higher in IPF (n = 87; 1.88 [0 to 5.68 pg/mL]), nonspecific interstitial pneumonia (n = 22; 0.58 [0 to 11.64 pg/mL]), and hypersensitivity pneumonitis (n = 19; 2.48 [0.46 to 5.71 pg/mL]) patients than in normal controls (n = 33; 0 [0 to 0.68 pg/mL]) (all p &lt; 0.01). A receiver operating characteristic curve showed a difference in G-CSF levels between IPF and NC (area under the curve, 0.769): The G-CSF cut-off of 0.96 pg/mL indicated 84.9% specificity and 63.2% sensitivity for IPF. The survival rate was significantly lower in the group with G-CSF &gt; 2.872 pg/mL than in the group with ≤ 2.872 pg/mL (hazard ratio, 2.69; p = 0.041). The annual decline in diffusing capacity of the lung for carbon monoxide was positively correlated with the G-CSF level (p = 0.018).

CONCLUSION

G-CSF may participate in the development of IPF and be useful for predicting the prognosis of IPF. Therefore, G-CSF should be analyzed in BALF, in addition to differential cell counts.

Investigation into the anti-airway inflammatory role of the PI3Kγ inhibitor JN-PK1: An in vitro and in vivo study

Phosphatidylinositol 3-kinase gamma (PI3Kγ) has been proven to be a potential target for the treatment of inflammatory diseases of the airway; however, there are few reports of selective PI3Kγ inhibitors being used in the field of airway inflammation thus far. Herein, a study employing in vitro and in vivo methodologies was carried out to assess the anti-airway inflammatory effects of JN-PK1, a selective PI3Kγ inhibitor. In RAW264.7 macrophages, JN-PK1 inhibited PI3Kγ-dependent, cellular C5a-induced AKT Ser473 phosphorylation in a concentration- and time-dependent manner and had no significant effect on cell viability.Furthermore, JN-PK1 significantly suppressed LPS-induced, proinflammatory cytokine expression and nitric oxide production through inhibition of the PI3K signaling pathway in RAW264.7 cells. Then, a murine asthma model was established to evaluate the anti-airway inflammation effect of JN-PK1. BALB/c mice were sensitized and challenged with ovalbumin (OVA) to develop an inflammatory response, fibrosis formation, and other airway changes similar to the symptomatology of asthma in humans. Oral administration of JN-PK1 remarkably attenuated OVA-induced asthma in association with the inhibition of the PI3K signaling pathway. That is to say, the oral administration significantly inhibited increases in inflammatory cell counts and reduced T-helper type 2 cytokine production in bronchoalveolar lavage fluid. Pulmonary histological studies showed that oral administration of JN-PK1 not only reduced the infiltration of inflammatory cells but also retarded airway inflammation and fibration. Taken together, JN-PK1 could be developed as a promising candidate for inflammation therapy, and our findings support some potential for therapeutic inhibition of PI3Kγ to treat inflammatory airway diseases.

Discovery of Aryloxyphenyl-Heptapeptide Hybrids as Potent and Selective Matrix Metalloproteinase-2 Inhibitors for the Treatment of Idiopathic Pulmonary Fibrosis

Matrix metalloproteinase-2 (MMP2) is a zinc-dependent endopeptidase that plays important roles in the degradation of extracellular matrix proteins. MMP2 is considered to be an attractive target for the treatment of various diseases such as cancer, arthritis, and fibrosis. In this study, we have developed a novel class of MMP2-selective inhibitors by hybridizing the peptide that binds to a zinc ion and S2-S5 pockets with small molecules that bind to the S1' pocket. Structural modifications based on X-ray crystallography revealed that the introduction of 2,4-diaminobutanoic acid (Dab) at position 4 dramatically enhanced MMP2 selectivity by forming an electrostatic interaction with Glu130. After improving the metabolic and chemical stability, TP0556351 (9) was identified. It exhibited potent MMP2 inhibitory activity (IC₅₀ = 0.20 nM) and extremely high selectivity. It suppressed the accumulation of collagen in a bleomycin-induced idiopathic pulmonary fibrosis model in mice, demonstrating the efficacy of MMP2-selective inhibitors for fibrosis.

Targeting Growth Factor and Cytokine Pathways to Treat Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease of unknown origin that usually results in death from secondary respiratory failure within 2–5 years of diagnosis. Recent studies have identified key roles of cytokine and growth factor pathways in the pathogenesis of IPF. Although there have been numerous clinical trials of drugs investigating their efficacy in the treatment of IPF, only Pirfenidone and Nintedanib have been approved by the FDA. However, they have some major limitations, such as insufficient efficacy, undesired side effects and poor pharmacokinetic properties. To give more insights into the discovery of potential targets for the treatment of IPF, this review provides an overview of cytokines, growth factors and their signaling pathways in IPF, which have important implications for fully exploiting the therapeutic potential of targeting cytokine and growth factor pathways. Advances in the field of cytokine and growth factor pathways will help slow disease progression, prolong life, and improve the quality of life for IPF patients in the future.

Advances in the design of new types of inhaled medicines

Inhalation of small molecule drugs has proven very efficacious for the treatment of respiratory diseases due to enhanced efficacy and a favourable therapeutic index compared with other dosing routes. It enables targeted delivery to the lung with rapid onset of therapeutic action, low systemic drug exposure, and thereby reduced systemic side effects. An increasing number of pharmaceutical companies and biotechs are investing in new modalities-for this review defined as therapeutic molecules with a molecular weight >800Da and therefore beyond usual inhaled small molecule drug-like space. However, our experience with inhaled administration of PROTACs, peptides, oligonucleotides (antisense oligonucleotides, siRNAs, miRs and antagomirs), diverse protein scaffolds, antibodies and antibody fragments is still limited. Investigating the retention and metabolism of these types of molecules in lung tissue and fluid will contribute to understanding which are best suited for inhalation. Nonetheless, the first such therapeutic molecules have already reached the clinic. This review will provide information on the physiology of healthy and diseased lungs and their capacity for drug metabolism. It will outline the stability, aggregation and immunogenicity aspects of new modalities, as well as recap on formulation and delivery aspects. It concludes by summarising clinical trial outcomes with inhaled new modalities based on information available at the end of 2021.

Autophagy modulation by irbesartan mitigates the pulmonary fibrotic alterations in bleomycin challenged rats: Comparative study with rapamycin

AIMS

In pulmonary fibrosis, autophagy handles the maintenance of alveolar epithelial cells, prevents epithelial-mesenchymal transition (EMT), and controls collagen turnover. The mammalian target of rapamycin (mTOR) and its translational-dependent proteins are essential regulators of autophagy. Irbesartan (IRB) has earlier ameliorative effects in experimental pulmonary fibrosis. The current study aimed to explore therapeutic autophagy-modulated pulmonary fibrotic changes by IRB versus rapamycin (RAPA) in bleomycin (BLM)-challenged rats.

MATERIALS AND METHODS

A single intratracheal BLM dose at day (0), IRB in different doses (10, 20, and 40 mg/kg) or RAPA (2.5 mg/kg) was given daily for 14 continuous days.

KEY FINDINGS

IRB significantly diminished the fibrotic lung scores. Pulmonary levels of transforming growth factor (TGF)-β1 and hydroxyproline exhibited marked attenuation in IRB (40 mg/kg)-treated rats compared to other treated groups. IRB (40 mg/kg) was not significantly different from RAPA. It downregulated the fibrotic lung phosphorylated mammalian target of rapamycin (p-mTOR) levels and augmented lung Unc-51-like autophagy activating kinase 1 (ULK1), LC3-I and LC3-II more than IRB (10 and 20 mg/kg)-treated fibrotic groups.

SIGNIFICANCE

Autophagic effects via the mTOR signalling pathway may play a role in IRB's antifibrotic effects. Consideration of IRB as a therapeutic antifibrotic agent in pulmonary fibrosis needs further experimental and clinical long-term validation, especially in comorbid with primary hypertension, heart failure, and diabetic renal insults.

Combined obstructive airflow limitation associated with interstitial lung diseases (O-ILD): the bad phenotype ?

BACKGROUND

Patients suffering from combined obstructive and interstitial lung disease (O-ILD) represent a pathological entity which still has to be well clinically described. The aim of this descriptive and explorative study was to describe the phenotype and functional characteristics of a cohort of patients suffering from functional obstruction in a population of ILD patients in order to raise the need of dedicated prospective observational studies and the evaluation of the impact of anti-fibrotic therapies.

METHODS

The current authors conducted a retrospective study including 557 ILD patients, with either obstructive (O-ILD, n = 82) or non-obstructive (non O-ILD, n = 475) pattern. Patients included were mainly males (54%) with a mean age of 62 years.

RESULTS

Patients with O-ILD exhibited a characteristic functional profile with reduced percent predicted forced expired volume in 1 s (FEV1) [65% (53-77) vs 83% (71-96), p < 0.00001], small airway involvement assessed by maximum expiratory flow (MEF) 25/75 [29% (20-41) vs 81% (64-108), p < 0.00001], reduced sGaw [60% (42-75) vs 87% (59-119), p < 0.01] and sub-normal functional residual capacity (FRC) [113% (93-134) vs 92% (75-109), p < 0.00001] with no impaired of carbon monoxide diffusing capacity of the lung (DLCO) compared to those without obstruction. Total lung capacity (TLC) was increased in O-ILD patients [93% (82-107) vs 79% (69-91), p < 0.00001]. Of interest, DLCO sharply dropped in O-ILD patients over a 5-year follow-up. We did not identify a significant increase in mortality in patients with O-ILD. Interestingly, the global mortality was increased in the specific sub-group of patients with O-ILD and no progressive fibrosing ILD phenotype and in those with connective tissue disease associated ILD especially in case of rheumatoid arthritis.

CONCLUSIONS

The authors individualized a specific functional-based pattern of ILD patients with obstructive lung disease, who are at risk of increased mortality and rapid DLCO decline over time. As classically those patients are excluded from clinical trials, a dedicated prospective study would be of interest in order to define more precisely treatment response of those patients.

Progress of Statin Therapy in the Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a type of interstitial lung disease (ILD) characterized by the proliferation of fibroblasts and aberrant accumulation of extracellular matrix. These changes are accompanied by structural destruction of the lung tissue and the progressive decline of pulmonary function. In the past few decades, researchers have investigated the pathogenesis of IPF and sought a therapeutic approach for its treatment. Some studies have shown that the occurrence of IPF is related to pulmonary inflammatory injury; however, its specific etiology and pathogenesis remain unknown, and no effective treatment, with the exception of lung transplantation, has been identified yet. Several basic science and clinical studies in recent years have shown that statins, the traditional lipid-lowering drugs, exert significant antifibrotic effects, which can delay the progression of IPF and impairment of pulmonary function. This article is aimed at summarizing the current understanding of the pathogenesis of IPF, the progress of research on the use of statins in IPF models and clinical trials, and its main molecular targets.

CDKN2B antisense RNA 1 expression alleviates idiopathic pulmonary fibrosis by functioning as a competing endogenouse RNA through the miR-199a-5p/Sestrin-2 axis

Idiopathic pulmonary fibrosis (IPF) is an idiopathic interstitial lung disease. At present, the pathogenesis of IPF has not been fully elucidated, which has affected the development of effective treatment methods. Here, we explored the function and potential mechanism of long noncoding RNA (lncRNA) CDKN2B antisense RNA 1 (CDKN2B-AS1) in IPF.Transforming growth factor-β (TGF-β) and bleomycin (BLM) were used to induce IPF in cells and animal models. Real Time quantitative Polymerase Chain Reaction (RT-qPCR) showed the expression of CDKN2B-AS1, miR-199a-5p and Sestrin-2 (SESN2) in cells and tissues. The double luciferase reporter gene assay confirmed the targeting relationship among CDKN2B-AS1, miR-199a-5p, and SESN2. Related protein levels were detected by Western blot combined with Cell Counting Kit-8 (CCK-8), wound healing, and flow cytometry to analyze cell proliferation, migration, and apoptosis. The pathological characteristics of mouse lung tissue were determined by Hematoxylin-eosin (HE) and Masson staining. We found that the expression of CDKN2B-AS1 was decreased in TGF-β-treated cells and BLM-treated mice. Overexpression of CDKN2B-AS1 inhibited cell proliferation and migration, promoted apoptosis, decreased the expression of fibrosis-related proteins and promoted autophagy. In addition, overexpression of CDKN2B-AS1 alleviated pulmonary fibrosis in BLM-treated mice. Mechanistically, CDKN2B-AS1 acts as a miR-199a-5p sponge to regulate SESN2 expression. Our results indicate the importance of the CDKN2B-AS1/miR-199a-5p/SESN2 axis.

Targeting Oxidative Stress as a Therapeutic Approach for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease characterized by an abnormal reepithelialisation, an excessive tissue remodelling and a progressive fibrosis within the alveolar wall that are not due to infection or cancer. Oxidative stress has been proposed as a key molecular process in pulmonary fibrosis development and different components of the redox system are altered in the cellular actors participating in lung fibrosis. To this respect, several activators of the antioxidant machinery and inhibitors of the oxidant species and pathways have been assayed in preclinical in vitro and in vivo models and in different clinical trials. This review discusses the role of oxidative stress in the development and progression of IPF and its underlying mechanisms as well as the evidence of oxidative stress in human IPF. Finally, we analyze the mechanism of action, the efficacy and the current status of different drugs developed to inhibit the oxidative stress as anti-fibrotic therapy in IPF.

Idiopathic Pulmonary Fibrosis: An Update on Pathogenesis

Idiopathic pulmonary fibrosis (IPF) is a progressive, lethal fibrotic lung disease that occurs primarily in middle-aged and elderly adults. It is a major cause of morbidity and mortality. With an increase in life expectancy, the economic burden of IPF is expected to continuously rise in the near future. Although the exact pathophysiological mechanisms underlying IPF remain not known. Significant progress has been made in our understanding of the pathogenesis of this devastating disease in last decade. The current paradigm assumes that IPF results from sustained or repetitive lung epithelial injury and subsequent activation of fibroblasts and myofibroblast differentiation. Persistent myofibroblast phenotype contributes to excessive deposition of the extracellular matrix (ECM) and aberrant lung repair, leading to tissue scar formation, distortion of the alveolar structure, and irreversible loss of lung function. Treatments of patients with IPF by pirfenidone and nintedanib have shown significant reduction of lung function decline and slowing of disease progression in patients with IPF. However, these drugs do not cure the disease. In this review, we discuss recent advances on the pathogenesis of IPF and highlight the development of novel therapeutic strategies against the disease.

Inhibition of RUNX1 blocks the differentiation of lung fibroblasts to myofibroblasts

Pathological fibrosis contributes to progression of various diseases, for which the therapeutic options are limited. Idiopathic pulmonary fibrosis (IPF) is one such progressive and fatal interstitial fibrotic disease that is often characterized by excessive accumulation of extracellular matrix (ECM) proteins leading to stiff lung tissue and impaired gas exchange. However, the molecular mechanisms underlying IPF progression remain largely unknown. In this study, we determined the role of Runt-related transcription factor 1 (RUNX1), an evolutionarily conserved transcription factor, in the differentiation of human lung fibroblasts (HLFs) in vitro and in an animal model of bleomycin (BLM)-induced lung fibrosis. We observed that the expression of RUNX1 was significantly increased in the lungs of BLM-injected mice as compared to saline-treated mice. Furthermore, HLFs stimulated with transforming growth factor β (TGF-β) showed significantly higher RUNX1 expression at both mRNA and protein levels, and compartmentalization in the nucleus. Inhibition of RUNX1 in HLFs (using siRNA) showed a significant reduction in the differentiation of fibroblasts into myofibroblasts as evidenced by reduced expression of alpha-smooth muscle actin (α-SMA), TGF-β and ECM proteins such as fibronectin 1 (FN1), and collagen 1A1 (COL1A1). Mechanistic studies revealed that the increased expression of RUNX1 in TGF-β-stimulated lung fibroblasts is due to enhanced mRNA stability of RUNX1 through selective interaction with the RNA-binding profibrotic protein, human antigen R (HuR). Collectively, our data demonstrate that increased expression of RUNX1 augments processes involved in lung fibrosis including the differentiation of fibroblasts into collagen-synthesizing myofibroblasts. Our study suggests that targeting RUNX1 could limit the progression of organ fibrosis in diseases characterized by abnormal collagen deposition.

Targeting PI3K/AKT signaling for treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrotic interstitial pneumonia with unknown causes. The incidence rate increases year by year and the prognosis is poor without cure. Recently, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/AKT) signaling pathway can be considered as a master regulator for IPF. The contribution of the PI3K/AKT in fibrotic processes is increasingly prominent, with PI3K/AKT inhibitors currently under clinical evaluation in IPF. Therefore, PI3K/AKT represents a critical signaling node during fibrogenesis with potential implications for the development of novel anti-fibrotic strategies. This review epitomizes the progress that is being made in understanding the complex interpretation of the cause of IPF, and demonstrates that PI3K/AKT can directly participate to the greatest extent in the formation of IPF or cooperate with other pathways to promote the development of fibrosis. We further summarize promising PI3K/AKT inhibitors with IPF treatment benefits, including inhibitors in clinical trials and pre-clinical studies and natural products, and discuss how these inhibitors mitigate fibrotic progression to explore possible potential agents, which will help to develop effective treatment strategies for IPF in the near future.

Novel imidazo[1,2-a]pyridine derivatives as potent ATX allosteric inhibitors: Design, synthesis and promising in vivo anti-fibrotic efficacy in mice lung model

Aiming to develop novel allosteric autotaxin (ATX) inhibitors, hybrid strategy was utilized by assembling the benzyl carbamate fragment in PF-8380 onto the imidazo[1,2-a]pyridine skeleton of GLPG-1690. The piperazine moiety in GLPG-1690 was replaced with phenyl ring to enhance the π-π interactions with adjacent residues. In the light of FS-3 based ATX enzymatic assay, further structure-guided optimizations were implemented by exploring the substituents within the carbamate aromatic moiety and examining the effect of the 2-ethyl. Eventually, 13c bearing 1,3-benzodioxole and 2-hydroxyethyl piperazine group was identified as a powerful ATX inhibitor with an IC₅₀ value of 2.7 nM. Subsequently, 13c was forwarded into an in vivo bleomycin-induced mice lung fibrosis model. In histopathological and immunohistochemical assays, 13c could typically alleviate the severity of fibrosis tissues and effectively reduce the deposition of fibrotic biomarker α-SMA. At a dose of 60 mg/kg, 13c was observed equivalent or even better potency than GLPG-1690 with a significant inhibition of the in vivo ATX activity. Except for the fundamental H-bond and π-π interactions, an extra H-bond between the 1,3-benzodioxole (O atom) and Phe306 offered great rationale in constraining the binding conformation of 13c. Finally, binding free energy calculation was conducted to assist in the efficient identification of allosteric ATX inhibitors.

Discovery of the c-Jun N-Terminal Kinase Inhibitor

As a result of emerging biological data suggesting that within the c-Jun N-terminal kinase (JNK) family, JNK1 and not JNK2 or JNK3 may be primarily responsible for fibrosis pathology, we sought to identify JNK inhibitors with an increased JNK1 bias relative to our previous clinical compound tanzisertib (CC-930). This manuscript reports the synthesis and structure-activity relationship (SAR) studies for a novel series of JNK inhibitors demonstrating an increased JNK1 bias. SAR optimization on a series of 2,4-dialkylamino-pyrimidine-5-carboxamides resulted in the identification of compounds possessing low nanomolar JNK inhibitory potency, overall kinome selectivity, and the ability to inhibit cellular phosphorylation of the direct JNK substrate c-Jun. Optimization of physicochemical properties in this series resulted in compounds that demonstrated excellent systemic exposure following oral dosing, enabling in vivo efficacy studies and the selection of a candidate for clinical development, CC-90001, which is currently in clinical trials (Phase II) in patients with idiopathic pulmonary fibrosis (NCT03142191).