To critically discuss the rationale for the use of drugs approved for idiopathic pulmonary fibrosis (IPF) to treat occupational interstitial lung diseases (OILDs).

Although IPF and OILDs share several clinical, radiological and probably pathogenetic features, currently, OILDs do not have a standard of care. In recent years, our knowledge and understanding of ILDs has improved substantially. Recently, the progressive pulmonary fibrosis (PPF) phenotype, which refers to non-IPF fibrotic ILDs that progress despite appropriate treatment, has been defined. OILDs may also be progressive. Nintedanib, initially approved for treatment of IPF, is also approved in patients with PPF. On the other hand, pirfenidone is approved in IPF but not in PPF, due to the lack of robust evidence of efficacy in this patient subset.

OILDs are a large and highly heterogeneous group of conditions without a proper standard of care. Nintedanib may slow functional decline and disease progression in progressive OILDs, and new clinical trials are ongoing.

This study advances sustainable pharmaceutical research for endometriosis by developing in vitro 3D cell culture models of endometriotic pathophysiology that allow antifibrotic drug candidates to be tested. Fibrosis is a key aspect of endometriosis, yet current cell models to study it remain limited. This work aims to bridge the translational gap between in vitro fibrosis research and preclinical testing of non-hormonal drug candidates. When grown in a 3D matrix of sustainably produced silk protein functionalized with a fibronectin-derived cell adhesion motif (FN-silk), endometrial stromal and epithelial cells respond to transforming growth factor beta-1 (TGF-β1) in a physiological manner as probed at the messenger RNA (mRNA) level. For stromal cells, this response to TGF-β1 is not observed in spheroids, while epithelial cell spheroids behave similarly to epithelial cell FN-silk networks. Pirfenidone, an antifibrotic drug approved for the treatment of idiopathic pulmonary fibrosis, reverses TGF-β1-induced upregulation of mRNA transcripts involved in fibroblast-to-myofibroblast transdifferentiation of endometrial stromal cells in FN-silk networks, supporting pirfenidone's potential as a repurposed non-hormonal endometriosis therapy. Overall, endometrial stromal cells cultured in FN-silk networks-which are composed of a sustainably produced, fully defined FN-silk protein-recapitulate fibrotic cellular behavior with high fidelity and enable antifibrotic drug testing.

Testicular injury and affected spermatogenesis are major complications of methotrexate (MTX) use. Oxidative stress is one contributing process leading to inflammation and apoptosis induction. Pirfenidone (PFD) is a well-known anti-fibrotic drug prescribed for interstitial lung fibrosis, in addition to anti-inflammatory, antioxidative, and antiapoptotic capabilities. The study aimed to explore the potential protection afforded by PFD in a rat model of MTX-induced testiculopathy. The experimental design included four groups, each containing seven adult Wistar rats: control, PFD (500 mg/kg/day, orally)-, MTX (0.5 mg/kg, intraperitoneal, twice weekly)-, and PFD/MTX-treated groups. Treatment continued for 4 weeks. Blood and testicular samples were harvested for biochemical, histological, immunohistochemical, and polymerase chain reaction (PCR) analyses. Also, the testicular damage and spermatogenic activity were graded by the testicular injury and Johnsen scoring system, respectively. PFD positively affected the serum testosterone (TST) level, reduced the testicular inflammatory mediators [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β)], reduced the testicular oxidative burden, increased superoxide dismutase (SOD), and protected the testicular histological structure. In addition, antifibrotic effects, anti-caspase-3, and PCNA enhancement activity were recorded. PFD exhibited a protective potential and mitigated the MTX-induced testiculopathy via suppression of testicular oxidative stress, inflammation, fibrosis, and apoptosis and retaining the testicular proliferative efficacy as confirmed by histological, immunohistochemical, and biochemical methods.

Liver fibrosis (LF) is a clinical disorder characterized by inflammation and excessive accumulation of extracellular matrix (ECM). This study investigates the effects of the antifibrotic compound pirfenidone (PFD) on improving LF through histological changes and modulation of eukaryotic translation initiation factor 6 (eIF6), P311, and transforming growth factor beta (TGF-β) in rats with bile duct ligation (BDL)-induced LF. Rats received daily doses of PFD (200 and 500 mg/kg) for 4 weeks. The study encompassed biochemical, pathological, and immunohistochemical (IHC) analyses. mRNA levels of eIF6, P311, TGF-β, ECM deposition, hepatic stellate cell (HSC) activation, and inflammatory mediator genes were measured by RT-qPCR. Protein levels of eIF6, P311, and TGF-β were detected by western blotting. Compared with the BDL group, PFD dose-dependently reduced hydroxyproline content, liver index, biochemical parameters, fibrosis score, and fibrosis area. PFD also modulated BDL-induced hepatic inflammation, ECM accumulation, and HSC activation. IHC staining of Ki-67 and hepatocyte paraffin-1 revealed that PFD enhanced liver regeneration. The research confirmed that PFD gradually downregulated elevated eIF6, P311, and TGF-β levels in BDL-induced LF. These findings suggest that PFD could be a potential treatment for LF, as it may help attenuate fibrosis and enhance liver regeneration, possibly through the modulation of these specific markers.

Cancer-associated fibroblasts (CAFs) are a heterogeneous cell population within the tumor that have recently come into the spotlight. By extracellular matrix (ECM) remodeling and robust cross-talk with cancer cells via different secretions such as cytokines, chemokines, and growth factors, CAFs contribute to cancer progression and poorer prognoses in patients. Novel candidates have been developed to inhibit CAFs; however, due to safety and efficacy issues, none have successfully passed clinical trials. Despite these shortcomings, one concept embraced by many researchers is to repurpose non-oncology drugs with potential anti-cancer properties for cancer treatment. One such example is pirfenidone (PFD), an oral anti-fibrotic medication, primarily administered for idiopathic pulmonary fibrosis. Emerging evidence suggests that PFD has promising anti-cancer effects, mainly manifesting through targeting CAFs. With inhibitory effects on CAFs, PFD restricts cancer proliferation, metastasis, immunosuppression, drug resistance, and tumor stiffness. To improve efficacy and minimize adverse effects, several innovative approaches have been proposed for targeting CAFs via PFD. Interestingly, combination therapy comprising PFD and chemotherapeutics e.g. doxorubicin has shown synergistic anti-cancer effects while protecting normal tissue. Furthermore, novel drug delivery systems, e.g. biomimetic liposomes and multilayer core-shell nanoparticles, have enhanced the pharmacokinetic properties of PFD and further increased its intratumoral delivery. Single-cell RNA sequencing (scRNA-seq) has also been suggested to characterize different subpopulations of CAFs and design precise PFD-based therapeutic strategies. Herein, we discuss the promising anti-cancer effects of PFD via inhibition of CAFs. We then provide findings on novel PFD-based approaches to target CAFs using combination therapy, nanocarrier-based drug delivery, and scRNA-seq.

The prevalence of many chronic noncommunicable diseases has been steadily rising over the past six decades. During this time, over 350,000 new chemical substances have been introduced to the lives of humans. In recent years, the epithelial barrier theory came to light explaining the growing prevalence and exacerbations of these diseases worldwide. It attributes their onset to a functionally impaired epithelial barrier triggered by the toxicity of the exposed substances, associated with microbial dysbiosis, immune system activation, and inflammation. Diseases encompassed by the epithelial barrier theory share common features such as an increased prevalence after the 1960s or 2000s that cannot (solely) be accounted for by the emergence of improved diagnostic methods. Other common traits include epithelial barrier defects, microbial dysbiosis with loss of commensals and colonization of opportunistic pathogens, and circulating inflammatory cells and cytokines. In addition, practically unrelated diseases that fulfill these criteria have started to emerge as multimorbidities during the last decades. Here, we provide a comprehensive overview of diseases encompassed by the epithelial barrier theory and discuss evidence and similarities for their epidemiology, genetic susceptibility, epithelial barrier dysfunction, microbial dysbiosis, and tissue inflammation.

Hedgehog (Hh) signaling is a well-established developmental pathway; it is crucial for early embryogenesis, cell differentiation, and damage-driven regeneration. It is being increasingly recognized that dysregulated Hh signaling is also involved in fibrotic diseases, which are characterized by excessive extracellular matrix deposition that compromises tissue architecture and function. As in-depth insights into the mechanisms of Hh signaling are obtained, its complex involvement in fibrosis is gradually being illuminated. Notably, some Hh-targeted inhibitors are currently under exploration in preclinical and clinical trials as a means to prevent fibrosis progression. In this review, we provide a concise overview of the biological mechanisms involved in Hh signaling. We summarize the latest advances in our understanding of the roles of Hh signaling in fibrogenesis across the liver, kidneys, airways, and lungs, as well as other tissues and organs, with an emphasis on both the shared features and, more critically, the distinct functional variations observed across these tissues and organs. We thus highlight the context dependence of Hh signaling, as well as discuss the current status and the challenges of Hh-targeted therapies for fibrosis.

In this editorial, we comment on the article by Lei et al, with a specific focus on the timing of the initiation of the antifibrotic agent pirfenidone (PFD) in the management of idiopathic pulmonary fibrosis (IPF) and its impact on lung function of IPF patients. PFD is an antifibrotic agent that is widely used in the management of IPF in both early and advanced stages. It inhibits various pathways and has antifibrotic, anti-inflammatory, and antioxidant properties. Despite dosage lowering, PFD slowed IPF progression and maintained functional capacity. The 6-min walk distance test indicated that patients tolerated adverse events well, and PFD significantly reduced the incidence of progression episodes and death. Even when a single disease-progression event occurred, continuing PFD treatment had benefits.

Smoke inhalation lung injury (SILI) is a common complication in fires and wars, characterized by acute onset and severe condition. Pirfenidone (PFD), a new small-molecule drug, has been shown to improve lung function and inhibit pulmonary fibrosis and inflammation. This study aimed to elucidate the effect and underlying mechanism of PFD on SILI in rats.

SILI rats were constructed using a homemade smoking device, which was then treated with PFD. The blood was collected from the abdominal aorta, and the arterial blood gas was detected. The productions of oxidative stress markers and inflammatory cytokines in plasma were measured by enzyme linked immunosorbent assay assay. Moreover, the alveolar surface area, wet:dry weight ratio of the lung tissues, and bronchoalveolar lavage fluid (BALF) were determined as well. The pulmonary histopathology, cell apoptosis, and the related proteins of nuclear factor kappa B (NF-κB) pathway were determined by hematoxylin-eosin staining, TdT-mediated dUTP-biotin nick end labeling, and western blot assays, respectively.

PFD had a significant protective effect on SILI via inhibiting oxidative stress, inflammation, and apoptosis. Mechanistically, PFD inhibited the activation of NF-κB pathway in vivo. Moreover, activation of NF-κB pathway attenuated the PFD-mediated protective effect against SILI.

These data demonstrate that PFD alleviates SILI of rats via the NF-κB signaling pathway, which provides an attractive therapeutic option for SILI treatment.

Nearly all medications carry the risk of drug-induced liver injury (DILI). Idiosyncratic reactions are rare and poorly predictable, and the mechanisms are not always well understood. Pirfenidone is an oral antifibrotic drug used to treat idiopathic pulmonary fibrosis. While elevation of liver enzymes is a common adverse reaction during therapy, it rarely leads to discontinuation or reduction of the drug. Although isolated cases of liver damage or liver failure have been reported, they are infrequent. This report presents the case of a 70-year-old woman with known idiopathic pulmonary fibrosis, depression, hypothyroidism, and hypercholesterolemia who presented at our emergency department with jaundice, anorexia, and asthenia. The patient's medication regimen included lamotrigine, simvastatin, levothyroxine, and pirfenidone, which had been introduced 6 months prior. Laboratory testing revealed elevated liver enzyme levels consistent with acute hepatocellular hepatitis. Following a medical workup, which included anamnesis, laboratory testing, iconographic investigations, and liver biopsy, we concluded that the patient had suffered from pirfenidone-induced liver injury. Pirfenidone was withdrawn, and liver tests gradually improved. The purpose of this clinical case report is to highlight this rare adverse reaction and to make clinicians aware of its assessment and management. In 2018, only one other case of severe liver failure leading to the death of the patient was reported. Early detection of potential DILI during the workup is crucial to discontinue the suspected medication promptly. Any drug-induced hepatitis must be reported for registration.

Pirfenidone is a groundbreaking antifibrotic agent that has become a cornerstone in managing fibrotic interstitial lung diseases (ILDs), particularly idiopathic pulmonary fibrosis (IPF). This review comprehensively analyzes pirfenidone's mechanisms of action, clinical efficacy, safety profile, and emerging applications beyond IPF. Pirfenidone exerts its therapeutic effects by inhibiting key pathways involved in fibrosis, including transforming growth factor-beta (TGF-β) and other pro-fibrotic cytokines. It also reduces oxidative stress and inflammation. Clinical trials have consistently demonstrated pirfenidone's ability to slow the decline in lung function, reduce disease progression, and improve survival rates in IPF patients. Furthermore, emerging evidence supports its potential use in other fibrotic ILDs and non-pulmonary fibrotic conditions, such as liver and kidney fibrosis. Despite its proven benefits, pirfenidone's safety and tolerability profiles require careful monitoring, with gastrointestinal and photosensitivity reactions being the most common adverse effects. Future research is poised to explore combination therapies, personalized treatment approaches, and novel applications of pirfenidone in a broader range of fibrotic disorders. As the field of antifibrotic therapy advances, pirfenidone remains a pivotal agent with the potential to significantly impact the management of fibrotic diseases across multiple organ systems. This review aims to provide clinicians and researchers with a detailed understanding of pirfenidone's current role and prospects in treating fibrosis.

The intricate tumor microenvironment in triple-negative breast cancer (TNBC) hampers chemotherapy and immunotherapy efficacy due to dense extracellular matrix (ECM) by tumor-associated fibroblasts (TAFs). Nanoparticle-based therapies, especially "all-in-one" nanoparticles, have shown great potential in combined drug delivery strategies to reshape the tumor microenvironment and enhance therapeutic efficiency. However, these "all-in-one" nanoparticles suffer from limitations in targeting different target cells, uncontrollable dosing ratio, and disregarding the impact of delivery schedules. This study prepared cell membrane fusion liposomes (TAFsomes and CCMsomes) to load FDA-approved antifibrotic drug pirfenidone (PFD/TAFsomes) and antitumor drug doxorubicin (DOX/CCMsomes). These liposomes can specifically target TAFs cells and tumor cells, and combined administration can effectively inhibit TAFs activity, reshape the tumor microenvironment (TME), and significantly enhance the tumor chemotherapy efficacy. Combined drug delivery defeats "all-in-one" liposomes (DOX/PFD/Liposomes, DOX/PFD/TAFsomes, and DOX/PFD/CCMsomes) by flexibly adjusting the drug delivery ratio. Moreover, an asynchronous delivery strategy that optimizes the administration schedule not only further improves the therapeutic effect, but also amplifies the effectiveness of α-PD-L1 immunotherapy by modulating the tumor immune microenvironment. This delivery strategy provides a personalized treatment approach with clinical translation potential, providing new ideas for enhancing the therapeutic effect against solid tumors such as TNBC.

Pirfenidone has demonstrated significant anti-inflammatory and antifibrotic effects in both animal models and some clinical trials. Its potential for antifibrotic activity positions it as a promising candidate for the treatment of various fibrotic diseases. Pirfenidone exerts several pleiotropic and anti-inflammatory effects through different molecular pathways, attenuating multiple inflammatory processes, including the secretion of pro-inflammatory cytokines, apoptosis, and fibroblast activation.

To present the current evidence of pirfenidone's effects on several fibrotic diseases, with a focus on its potential as a therapeutic option for managing chronic fibrotic conditions.

Pirfenidone has been extensively studied for idiopathic pulmonary fibrosis, showing a favorable impact and forming part of the current treatment regimen for this disease. Additionally, pirfenidone appears to have beneficial effects on similar fibrotic diseases such as interstitial lung disease, myocardial fibrosis, glomerulopathies, aberrant skin scarring, chronic liver disease, and other fibrotic disorders.

Given the increasing incidence of chronic fibrotic conditions, pirfenidone emerges as a potential therapeutic option for these patients. However, further clinical trials are necessary to confirm its therapeutic efficacy in various fibrotic diseases. This review aims to highlight the current evidence of pirfenidone's effects in multiple fibrotic conditions.

Pirfenidone (PFD), one acceptable medication for treating idiopathic pulmonary fibrosis (IPF), is not well tolerated by patients at full doses. Hence, employing of some approaches such as combination therapy may be applicable for increasing therapeutic efficacy of PFD. Losartan (LOS), an angiotensin II receptor antagonist, could be a suitable candidate for combination therapy because of its stabilizing effect on the pulmonary function of IPF patients. Therefore, this study aimed to investigate the effects of LOS in combination with PFD on bleomycin (BLM)-induced lung fibrosis in rats. BLM-exposed rats were treated with LOS alone or in combination with PFD. The edema, pathological changes, level of transforming growth factor-β (TGF-β1), collagen content, and oxidative stress parameters were assessed in the lung tissues. Following BLM exposure, the inflammatory response, collagen levels, and antioxidant markers in rat lung tissues were significantly improved by PFD, and these effects were improved by combination with LOS. The findings of this in vivo study suggest that the combined administration of PFD and LOS may provide more potent protection against IPF than single therapy through boosting its anti-inflammatory, anti-fibrotic, and anti-oxidant effects. These results hold promise in developing a more effective therapeutic strategy for treating of lung fibrosis.

In this work, the cytotoxicity of monoclonal antibody (Cetuximab, Ce) and Fenbendazole (Fen), as well as their combination therapy were tested with the MTT assay. On the other side, Ce, Fen, and a combination between them were subjected to a colchicine-tubulin binding test, which was conducted and compared to Colchicine as a reference standard. Besides, Ce, Fen, and the combination of them were tested against the VEGFR-2 target receptor, compared to Sorafenib as the standard medication. Moreover, the qRT-PCR technique was used to investigate the levels of apoptotic genes (p53 and Bax) and anti-apoptotic gene (Bcl-2) as well. Also, the effect of Ce, Fen, and the combination of them on the level of ROS was studied. Furthermore, the cell cycle analysis and Annexin V apoptosis assay were carried out for Ce, Fen, and a combination of them. In addition, the molecular docking studies were used to describe the molecular levels of interactions for both (Fen and colchicine) or (Fen and sorafenib) within the binding pockets of the colchicine binding site (CBS) and vascular endothelial growth factor-2 receptor (VEGFR-2), respectively.

Alcohol consumption increases the risk of breast cancer and promotes cancer progression. Alcohol exposure could affect both processes of the mammary carcinogenesis, namely, the cell transformation and onset of tumorigenesis as well as cancer aggressiveness including metastasis and drug resistance/recurrence. However, the cellular and molecular mechanisms underlying alcohol tumor promotion remain unclear. There are four members of the mammalian p38 mitogen-activated protein kinase (MAPK) family, namely, p38α, p38β, p38γ and p38δ. We have previously demonstrated alcohol exposure selectively activated p38γ MAPK in breast cancer cells in vitro and in vivo. Pirfenidone (PFD), an antifibrotic compound approved for the treatment of idiopathic pulmonary fibrosis, is also a pharmacological inhibitor of p38γ MAPK. This study aimed to determine whether PFD is useful to inhibit alcohol-induced promotion of breast cancer.

Female adolescent (5 weeks) MMTV-Wnt1 mice were exposed to alcohol with a liquid diet containing 6.7% ethanol. Some mice received intraperitoneal (IP) injection of PFD (100 mg/kg) every other day. After that, the effects of alcohol and PFD on mammary tumorigenesis and metastasis were examined.

Alcohol promoted the progression of mammary tumors in adolescent MMTV-Wnt1 mice. Treatment of PFD blocked tumor growth and alcohol-promoted metastasis. It also significantly inhibited alcohol-induced tumorsphere formation and cancer stem cell (CSC) population.

PFD inhibited mammary tumor growth and alcohol-promoted metastasis. Since PFD is an FDA-approved drug, the current findings may be helpful to re-purpose its application in treating aggressive breast cancer and alcohol-promoted mammary tumor progression.

Oxidative stress refers to the imbalance between the production of reactive oxygen species (ROS) and the endogenous antioxidant defense system. Its involvement in cell senescence, apoptosis, and series diseases has been demonstrated. Advances in carcinogenic research have revealed oxidative stress as a pivotal pathophysiological pathway in tumorigenesis and to be involved in lung cancer, glioma, hepatocellular carcinoma, leukemia, and so on. This review combs the effects of oxidative stress on tumorigenesis on each phase and cell fate determination, and three features are discussed. Oxidative stress takes part in the processes ranging from tumorigenesis to tumor death via series pathways and processes like mitochondrial stress, endoplasmic reticulum stress, and ferroptosis. It can affect cell fate by engaging in the complex relationships between senescence, death, and cancer. The influence of oxidative stress on tumorigenesis and progression is a multi-stage interlaced process that includes two aspects of promotion and inhibition, with mitochondria as the core of regulation. A deeper and more comprehensive understanding of the effects of oxidative stress on tumorigenesis is conducive to exploring more tumor therapies.

Metastasis is an important contributor to increased mortality rates in non-small cell lung cancer (NSCLC). The TGF-β signalling pathway plays a crucial role in facilitating tumour metastasis through epithelial-mesenchymal transition (EMT). Glycolysis, a key metabolic process, is strongly correlated with NSCLC metastasis. Pirfenidone (PFD) has been shown to safely and effectively inhibit TGF-β1 in patients with lung diseases. Furthermore, TGF-β1 and glycolysis demonstrate an interdependent relationship within the tumour microenvironment. Our previous study demonstrated that PFD effectively inhibited glycolysis in NSCLC cells, prompting further investigation into its potential antitumour effects in this context. Therefore, the present study aims to investigate the potential antitumour effect of PFD in NSCLC and explore the relationship among TGF-β1, glycolysis and EMT through further experimentation. The antitumour effects of PFD were evaluated using five different NSCLC cell lines and a xenograft tumour model. Notably, PFD demonstrated a significant antitumour effect specifically in highly glycolytic H1299 cells. To elucidate the underlying mechanism, we compared the efficacy of PFD after pretreatment with either TGF-β1 or a TGF-β receptor inhibitor (LY2109761). The energy metabolomics analysis of tumour tissue demonstrated that PFD, a chemosensitizing agent, reduced lactate and ATP production, thereby inhibiting glycolysis and exerting synergistic antineoplastic effects. Additionally, PFD combined with cisplatin targeted TGF-β1 to inhibit glycolysis during EMT and enhanced the chemosensitization of A549 and H1299 cells. The magnitude of the anticancer effect exhibited by PFD was intricately linked to its metabolic properties.

Nowadays, diabetes mellitus has emerged as a significant global public health concern with a remarkable increase in its prevalence. This review article focuses on the definition of diabetes mellitus and its classification into different types, including type 1 diabetes (idiopathic and fulminant), type 2 diabetes, gestational diabetes, hybrid forms, slowly evolving immune-mediated diabetes, ketosis-prone type 2 diabetes, and other special types. Diagnostic criteria for diabetes mellitus are also discussed. The role of inflammation in both type 1 and type 2 diabetes is explored, along with the mediators and potential anti-inflammatory treatments. Furthermore, the involvement of various organs in diabetes mellitus is highlighted, such as the role of adipose tissue and obesity, gut microbiota, and pancreatic β-cells. The manifestation of pancreatic Langerhans β-cell islet inflammation, oxidative stress, and impaired insulin production and secretion are addressed. Additionally, the impact of diabetes mellitus on liver cirrhosis, acute kidney injury, immune system complications, and other diabetic complications like retinopathy and neuropathy is examined. Therefore, further research is required to enhance diagnosis, prevent chronic complications, and identify potential therapeutic targets for the management of diabetes mellitus and its associated dysfunctions.

The COVID-19 pandemic ignited research centered around the identification of robust biomarkers and therapeutic targets. SARS-CoV-2, the virus responsible, hijacks the metabolic machinery of the host cells. It relies on lipids and lipoproteins of host cells for entry, trafficking, immune evasion, viral replication, and exocytosis. The infection causes host cell lipid metabolic remodelling. Targeting lipid-based processes is thus a promising strategy for countering COVID-19. Here, we review the role of lipids in the different steps of the SARS-CoV-2 pathogenesis and identify lipid-centric targetable avenues. We discuss lipidome changes in infected patients and their relevance as potential clinical diagnostic or prognostic biomarkers. We summarize the emerging direct and indirect therapeutic approaches for targeting COVID-19 using lipid-inspired approaches. Given that viral protein-targeted therapies may become less effective due to mutations in emerging SARS-CoV-2 variants, lipid-inspired interventions may provide additional and perhaps better means of combating this and future pandemics.

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by a progressive decline in lung function and poor prognosis. The deposition of the extracellular matrix (ECM) by myofibroblasts contributes to the stiffening of lung tissue and impaired oxygen exchange in IPF. Type I collagen is the major ECM component and predominant collagen protein deposited in chronic fibrosis, suggesting that type I collagen could be a target of drugs for fibrosis treatment. Heat shock protein 47 (HSP47), encoded by the serpin peptidase inhibitor clade H, member 1 gene, is a stress-inducible collagen-binding protein. It is an endoplasmic reticulum-resident molecular chaperone essential for the correct folding of procollagen. HSP47 expression is increased in cellular and animal models of pulmonary fibrosis and correlates with pathological manifestations in human interstitial lung diseases. Various factors affect HSP47 expression directly or indirectly in pulmonary fibrosis models. Overall, understanding the relationship between HSP47 expression and pulmonary fibrosis may contribute to the development of novel therapeutic strategies.

Excessive scar formation is a hallmark of localized and systemic fibrotic disorders. Despite extensive studies to define valid anti-fibrotic targets and develop effective therapeutics, progressive fibrosis remains a significant medical problem. Regardless of the injury type or location of wounded tissue, excessive production and accumulation of collagen-rich extracellular matrix is the common denominator of all fibrotic disorders. A long-standing dogma was that anti-fibrotic approaches should focus on overall intracellular processes that drive fibrotic scarring. Because of the poor outcomes of these approaches, scientific efforts now focus on regulating the extracellular components of fibrotic tissues. Crucial extracellular players include cellular receptors of matrix components, macromolecules that form the matrix architecture, auxiliary proteins that facilitate the formation of stiff scar tissue, matricellular proteins, and extracellular vesicles that modulate matrix homeostasis. This review summarizes studies targeting the extracellular aspects of fibrotic tissue synthesis, presents the rationale for these studies, and discusses the progress and limitations of current extracellular approaches to limit fibrotic healing.

Severe stages of COVID-19 infection have been associated with the excessive discharge of pro-inflammatory mediators such as cytokines, resulting in lung deterioration, which progresses rapidly to lung fibrosis leading to acute respiratory distress syndrome. In this investigation, the efficacy and safety of the novel antifibrotic and anti-inflammatory agent, Pirfenidone, were assessed in COVID-19 patients with pulmonary fibrosis secondary to cytokine storm. In this randomized controlled study, we assigned 100 adult COVID-19 patients cytokine storm and admitted to the intensive care isolation unit into either pirfenidone added to the standard therapy (n = 47), or the standard protocol only (n = 53). High-resolution computed tomography of the chest was performed in all patients to evaluate fibrotic lesions and their progression. The results showed that the percentage of patients who developed pulmonary fibrosis during cytokine storm onset in the pirfenidone group relative to the standard group was 29.8% and 35.8%, respectively, with no significant difference between the two groups; while there was a significant increase in the proportion of patients discharged from the isolation unit with pulmonary fibrosis without progression in fibrotic lesions in the pirfenidone group compared to the standard group (21.3% and 5.7%, respectively). Furthermore, there was a significant difference concerning liver enzyme elevation and GIT disturbance incidences in the studied groups (p = 0.006 and 0.01, respectively). Our findings show that Pirfenidone inhibits fibrosis advancement in COVID-19 patients with pulmonary fibrosis and is associated with hepatotoxicity and GI distress. It may be beneficial in patients with mild to moderate COVID-19-induced pulmonary fibrosis; however, additional research is necessary.