The multifaceted role of pirfenidone and its novel targets

Pirfenidone: A Promising Drug in Ocular Therapeutics

Pirfenidone, initially indicated for lung fibrosis, has gone beyond its original purpose, and shown promise in eye care. This detailed review tracks its evolution from lung treatment to aiding eye healing as evidenced by published literature. Pirfenidone's multifaceted attributes extend to mitigating corneal fibrosis, inflammation, and trauma. Through rigorous investigations, its efficacy emerges in diabetic retinopathy, macular degeneration, and postoperative glaucoma interventions. As an unheralded protagonist, pirfenidone reshapes ocular care paradigms, inviting renewed research opportunities.

Pre-transplant anti-fibrotics for idiopathic pulmonary fibrosis: Are we seeing a new role for the anti-fibrotics?

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Prolonged release pirfenidone pharmacokinetics is modified in cirrhosis GENESIS study

BACKGROUND

In both clinical and experimental trials, pirfenidone (PFD) showed anti-inflammatory and antifibrogenic effects. Considering the wide variation in hepatic functional reserve in patients with cirrhosis, we decided to learn more about the pharmacokinetics of a new formulation of prolonged release PFD in this population (PR-PFD), focusing on assessing changes on AUC0-∞, AUC0-t, and Cmax.

METHODS

In this study, 24 subjects with cirrhosis were included: eight subjects with mild liver impairment (Child-Pugh A) and eight with moderate liver impairment (Child-Pugh B), and a third group of eight age-matched subjects without fibrosis. All participants were under fasting conditions before receiving orally two 600-mg tablets of a prolonged-release formulation of pirfenidone (PR-PFD) and remained in the clinical unit for 36 h after PR-PFD administration. Serial blood samples were collected after dosing (0.5-36 h). A validated high-performance liquid chromatography-mass spectrometry method was used to determine PFD plasma concentrations.

RESULTS

The exposure to PR-PFD was 3.6- and 4.4-fold greater in subjects with Child-Pugh A and Child-Pugh B than in subjects without cirrhosis, and Cmax was 1.6- and 1.8-fold greater in subjects with Child-Pugh B and Child-Pugh-A than in patients without cirrhosis, without significant differences between the two cirrhotic groups. PFD was well tolerated.

CONCLUSION

The pharmacokinetic parameters of PR-PFD are significantly modified in patients with cirrhosis compared with those in controls, indicating that liver impairment should be considered in clinical practice.

Implant-based breast surgery and capsular formation: when, how and why?-a narrative review

Background and Objective

Implant-based breast surgery is a common procedure for both reconstructive and aesthetic purposes. Breast implants, like any foreign object, trigger the formation of a capsule around them. While generally harmless, the capsule can undergo fibrotic changes leading to capsular contracture, which can negatively impact surgical outcomes and patient well-being. Additionally, rare but serious complications, such as breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) and capsule-associated squamous cell carcinoma, have been reported. This paper aims to review the physiology of capsular formation, identify factors contributing to capsule-related pathologies, and discuss their clinical implications.

Methods

A review of relevant literature was conducted by searching databases for articles published between inception and September 2022. The search included but not limited to terms such as "capsular formation" and "capsular contracture". Selected articles were critically analyzed to address the objectives of this review.

Key Content and Findings

Capsular formation involves interactions between the implant surface, surrounding tissues, and the immune system. Factors influencing pathological changes in the capsule include genetic predisposition, bacterial contamination, implant characteristics, and surgical techniques. Capsular contracture, characterized by tissue hardening, pain, and implant distortion, remains the most common complication. Rare but life-threatening conditions, such as BIA-ALCL and capsule-associated squamous cell carcinoma, necessitate vigilant monitoring and early detection.

Conclusions

Understanding the physiology of capsular formation and its associated pathologies is crucial for healthcare providers involved in implant-based breast surgery. Efforts should focus on minimizing the risk of capsular contracture through improved implant materials, surgical techniques, and infection prevention. The emergence of BIA-ALCL and capsule-associated squamous cell carcinoma underscores the importance of long-term surveillance and prompt diagnosis. Further research is needed to uncover underlying mechanisms and develop preventive measures and treatments for these complications. Enhancing our knowledge and clinical management of capsular formation will lead to safer and more successful outcomes in implant-based breast surgery.

Sarcoidosis-associated pulmonary fibrosis: joining the dots

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. A minority of patients with sarcoidosis develop sarcoidosis-associated pulmonary fibrosis (SAPF), which may become progressive. Genetic profiles differ between patients with progressive and self-limiting disease. The mechanisms of fibrosis in SAPF are not fully understood, but SAPF is likely a distinct clinicopathological entity, rather than a continuum of acute inflammatory sarcoidosis. Risk factors for the development of SAPF have been identified; however, at present, it is not possible to make a robust prediction of risk for an individual patient. The bulk of fibrotic abnormalities in SAPF are located in the upper and middle zones of the lungs. A greater extent of SAPF on imaging is associated with a worse prognosis. Patients with SAPF are typically treated with corticosteroids, second-line agents such as methotrexate or azathioprine, or third-line agents such as tumour necrosis factor inhibitors. The antifibrotic drug nintedanib is an approved treatment for slowing the decline in lung function in patients with progressive fibrosing interstitial lung diseases, but more evidence is needed to assess its efficacy in SAPF. The management of patients with SAPF should include the identification and treatment of complications such as bronchiectasis and pulmonary hypertension. Further research is needed into the mechanisms underlying SAPF and biomarkers that predict its clinical course.

A Soft Skin Adhesive (SSA) Patch for Extended Release of Pirfenidone in Burn Wounds

As much as half or more of deep partial-thickness burn wounds develop hypertrophic scarring and contracture. Once formed, treatments are only minimally effective. Pirfenidone (Pf), indicated for treatment of idiopathic pulmonary fibrosis, is an anti-inflammatory and anti-fibrotic small molecule that potentially can be repurposed as a preventative against scarring in burn wounds. We present a drug-in-matrix patch with a soft skin adhesive (SSA) wound-contacting layer for multi-day drug delivery of Pf into burn wounds at the point of injury. Our patch construction consists of an SSA adhesive layer (Liveo™ MG7-9850, Dupont, Wilmington, DE, USA) for wound fixation, an acrylic co-polymer drug matrix (DURO-TAK 87-2852, Henkel, Düsseldorf, Germany) as the drug (Pf) reservoir, and an outermost protective polyurethane backing. By employing a drug-in-matrix patch design, Pf can be loaded as high as 2 mg/cm². Compared to the acrylic co-polymer adhesive patch preparations and commercial films, adding an SSA layer markedly reduces skin stripping observed under scanning electron microscopy (SEM). Moreover, the addition of varying SSA thicknesses did not interfere with the in vitro release kinetics or drug permeation in ex vivo porcine skin. The Pf patch can be easily applied onto and removed from deep partial-thickness burn wounds on Duroc pigs. Continuous multi-day dosing of Pf by the patches (>200 μg/cm²/day) reduced proinflammatory biomarkers in porcine burn wounds. Pf patches produced by the manual laboratory-scale process showed excellent stability, maintaining intact physical patch properties and in vitro biological activity for up to one year under long-term (25 °C at 60% RH) and 6 months under accelerated (40 °C at 75% RH) test conditions. To manufacture our wound safe-and-extended-release patch, we present scale-up processes using a machine-driven automated roll-to-roll pilot scale coater.

Triple-negative breast cancer cells invade adipocyte/preadipocyte-encapsulating geometrically inverted mammary organoids

This paper describes the manufacture of geometrically inverted mammary organoids encapsulating primary mammary preadipocytes and adipocytes. Material manipulation in an array of 192 hanging drops induces cells to self-assemble into inside-out organoids where an adipose tissue core is enveloped by a cell-produced basement membrane, indicated by laminin V staining and then a continuous layer of mammary epithelial cells. This inverted tissue structure enables investigation of multiple mammary cancer subtypes, with a significantly higher extent of invasion by triple-negative MDA-MB-231 breast cancer cells compared to MCF7 cells. By seeding cancer cells into co-culture around pre-formed organoids with encapsulated preadipocytes/adipocytes, invasion through the epithelium, then into the adipose core is observable through acquisition of confocal image stacks of whole mount specimens. Furthermore, in regions of the connective tissue core where invasion occurs, there is an accumulation of collagen in the microenvironment. Suggesting that this collagen may be conducive to increased invasiveness, the anti-fibrotic drug pirfenidone shows efficacy in this model by slowing invasion. Comparison of adipose tissue derived from three different donors shows method consistency as well as the potential to evaluate donor cell-based biological variability. Insight box Geometrically inverted mammary organoids encapsulating primary preadipocytes/adipocytes (P/As) are bioengineered using a minimal amount of Matrigel scaffolding. Use of this eversion-free method is key to production of adipose mammary organoids (AMOs) where not only the epithelial polarity but also the entire self-organizing arrangement, including adipose position, is inside-out. While an epithelial-only structure can analyze cancer cell invasion, P/As are required for invasion-associated collagen deposition and efficacy of pirfenidone to counteract collagen deposition and associated invasion. The methods described strike a balance between repeatability and preservation of biological variability: AMOs form consistently across multiple adipose cell donors while revealing cancer cell invasion differences.

Pirfenidone Protects from UVB-Induced Photodamage in Hairless Mice

Background: Ultraviolet radiation (UV) is the main environmental factor that causes histological degenerative changes of the skin giving rise to a chronic process called photodamage. Non-melanoma skin cancer induced by UVB radiation is a result of a cascade of molecular events caused by DNA damage in epidermis cells, including persistent inflammation, oxidative stress, and suppression of T cell-mediated immunity. Retinoids such as tretinoin have been widely used in skin to treat photoaging and photodamage, though its secondary adverse effects have been recognized. Pirfenidone (PFD) has emerged as an antifibrogenic, anti-inflammatory and antioxidant agent, and in this work its efficacy was evaluated in a model of UVB-induced photodamage. Methods: Epidermal, dermal, and inflammatory changes were measured by histomorphometric parameters. In addition, gene, and protein expression of key molecules in these processes were evaluated. Results: Our results revealed an anti-photodamage effect of topical PFD with absence of inflammatory skin lesions determined by dermoscopy. In addition, PFD reduced elastosis, improved organization, arrangement, and deposition of dermal collagens, downregulated several pro-inflammatory markers such as NF-kB, IL-1, IL-6 and TNFα, and decreased keratinocyte damage. Conclusion: Topical pirfenidone represents a promising agent for the treatment of cell photodamage in humans. Clinical trials need to be carried out to explore this premise.

Antifibrotic Effects of Caffeine, Curcumin and Pirfenidone in Primary Human Keratocytes

We evaluated the small molecules (AFM) caffeine, curcumin and pirfenidone to find non-toxic concentrations reducing the transformation of activated human corneal stromal keratocytes (aCSK) to scar-inducing myofibroblasts (MYO-SF). CSK were isolated from 16 human corneas unsuitable for transplantation and expanded for three passages in control medium (0.5% FBS). Then, aCSK were exposed to concentrations of caffeine of 0−500 μM, curcumin of 0−200 μM, pirfenidone of 0−2.2 nM and the profibrotic cytokine TGF-β1 (10 ng/mL) for 48 h. Alterations in viability and gene expression were evaluated by cell viability staining (FDA/PI), real-time polymerase chain reaction (RT-PCR) and immunocytochemistry. We found that all AFMs reduced cell counts at high concentrations. The highest concentrations with no toxic effect were 100 µM of caffeine, 20 µM of curcumin and 1.1 nM of pirfenidone. The addition of TGF-β1 to the control medium effectively transformed aCSK into myofibroblasts (MYO-SF), indicated by a 10-fold increase in α-smooth muscle actin (SMA) expression, a 39% decrease in lumican (LUM) expression and a 98% decrease in ALDH3A1 expression (p < 0.001). The concentrations of 100 µM of caffeine, 20/50 µM of curcumin and 1.1 nM of pirfenidone each significantly reduced SMA expression under TGF-β1 stimulation (p ≤ 0.024). LUM and ALDH3A1 expression remained low under TGF-β1 stimulation, independently of AFM supplementation. Immunocytochemistry showed that 100 µM of caffeine, 20 µM of curcumin and 1.1 nM of pirfenidone reduce the conversion rate of aCSK to SMA+ MYO-SF. In conclusion, in aCSK, 100 µM of caffeine, 20 µM of curcumin and 1.1 nM of pirfenidone significantly reduced SMA expression and MYO-SF conversion under TGF-β1 stimulation, with no influence on cell counts. However, the AFMs were unable to protect aCSK from characteristic marker loss.

Inhaled deep eutectic solvent based-nanoemulsion of pirfenidone in idiopathic pulmonary fibrosis

Pirfenidone (PRF), the first FDA-approved drug to treat idiopathic pulmonary fibrosis (IPF) and formulated as an oral dosage form, has many side effects. To enhance the therapeutic effect, we discovered a high-load nanoemulsion using a novel deep eutectic solvent (DES) and developed an inhalation drug with improved bioavailability. The DES of PRF and N-acetylcysteine were discovered, and their physicochemical properties were evaluated in this study. The mechanism of DES formation was confirmed by FT-IR and ¹H NMR and suggested to involve hydrogen bonding. The DES nanoemulsion in which the nano-sized droplets were dispersed is optimized by mixing the DES and distilled water in a ratio. The in vivo pharmacokinetic study showed that the pulmonary route of administration is superior to that of the oral route, and the DES nanoemulsion is superior to that of the PRF solution in achieving better bioavailability and lung distribution. The therapeutic effect of PRF for IPF could be confirmed through in vivo pharmacodynamics studies, including lung function assessment, enzyme-linked immunosorbent assay, histology, and micro-computed tomography using the bleomycin-induced IPF rat model. In addition, the pulmonary route administration of PRF is advantageous in reducing the toxicity risk.

Pharmacological basis of the antifibrotic effects of pirfenidone: Mechanistic insights from cardiac in-vitro and in-vivo models

Pirfenidone is a small drug with marked antifibrotic activity approved for the treatment of Idiopathic pulmonary fibrosis. Recently, its peculiar pharmacological profile has attracted attention for its potential therapeutic benefit for extra-pulmonary disorders characterized by pathological fibrosis, such as kidney, liver, and cardiac failure. A major pitfall of pirfenidone is the lack of consistent understanding of its mechanism of action, regardless of the target. In addition to the increasing attention to the role of inflammation and its mediators in several processes, a better knowledge of the variety of fibroblasts' population, of signals controlling their activation and trans-differentiation, and of crosstalk with other cell resident and non-resident cell types is needed for prevention, treatment and possibly reverse of fibrosis. This review will focus on pirfenidone's pharmacological profile and its effects on cardiac fibroblasts.

Nintedanib modulates type III collagen turnover in viable precision-cut lung slices from bleomycin-treated rats and patients with pulmonary fibrosis

BACKGROUND

Aberrant extracellular matrix (ECM) deposition and remodelling is important in the disease pathogenesis of pulmonary fibrosis (PF). We characterised neoepitope biomarkers released by ECM turnover in lung tissue from bleomycin-treated rats and patients with PF and analysed the effects of two antifibrotic drugs: nintedanib and pirfenidone.

METHODS

Precision-cut lung slices (PCLS) were prepared from bleomycin-treated rats or patients with PF. PCLS were incubated with nintedanib or pirfenidone for 48 h, and levels of neoepitope biomarkers of type I, III and VI collagen formation or degradation (PRO-C1, PRO-C3, PRO-C6 and C3M) as well as fibronectin (FBN-C) were assessed in the culture supernatants.

RESULTS

In rat PCLS, incubation with nintedanib led to a reduction in C3M, reflecting type III collagen degradation. In patient PCLS, incubation with nintedanib reduced the levels of PRO-C3 and C3M, thus showing effects on both formation and degradation of type III collagen. Incubation with pirfenidone had a marginal effect on PRO-C3. There were no other notable effects of either nintedanib or pirfenidone on the other neoepitope biomarkers studied.

CONCLUSIONS

This study demonstrated that nintedanib modulates neoepitope biomarkers of type III collagen turnover and indicated that C3M is a promising translational neoepitope biomarker of PF in terms of therapy assessment.

A new approach based on CXCR4-targeted combination liposomes for the treatment of liver fibrosis

Liver fibrosis results from excessive extracellular matrix accumulation due to injury and leads to cirrhosis, cancer, and death. Herein, we propose a chemokine receptor 4 (CXCR4)-targeted combination (CTC) liposomal therapy to treat carbon tetrachloride (CCl₄)-induced liver fibrosis in a mouse model. This study aims to combine small molecules such as pirfenidone and AMD3100 in a single nanoplatform to investigate their synergistic antifibrotic effects in a setting of CCl₄-induced liver fibrosis. CTC liposomes (CTC lipo) were prepared using the thin-film hydration method. CTC lipo exhibited a spherical shape, and the particle size was recorded at the nanoscale which confirms its appropriateness for in vitro and in vivo applications. CTC lipo had good storage and serum stability. The entrapped drugs in CTC lipo showed reduced toxicity at higher concentrations. CTC lipo displayed CXCR4 mediated cell uptake and were internalized by caveolae-mediated endocytosis. CTC lipo showed CXCR4 targeting and stromal cell-derived factor 1α (SDF1-α)/CXCR4 axis blocking activity. CTC lipo reduced the elevated serum aspartate aminotransferase (AST), alanine transaminase (ALT), and hydroxyproline (HYP) levels. The histological studies showed improved liver architecture and reduced collagen deposition after treatment. Transforming growth factor β (TGFβ), alpha-smooth muscle actin (α-SMA), and collagen I were elevated by CCl₄ in comparison with the Sham. Upon CTC liposomal treatment, the quantitative score for the elevated fibrotic proteins such as TGFβ, α-SMA, and collagen I was normalized. CTC lipo displayed significant downregulation of the upregulated TGFβ, α-SMA, collagen I, and P-p38 expressions at the molecular level. The CXCR4 targeted liposomes showed prolonged biodistribution at 24 h. Our findings indicated that CTC lipo might be an alternative antifibrotic therapy that may offer new access to research and development. In a nutshell, the present study suggests that systemic administration of CTC lipo has efficient antifibrotic potential and deserves to be investigated for further clinical applications.

The role of antifibrotic therapies in the treatment of systemic sclerosis-associated interstitial lung disease

Systemic sclerosis (SSc) is a rare autoimmune condition with complex pathogenesis characterized by a heterogeneous presentation and different disease courses. Fibrosis of multiple organs including the lungs favored by inflammation and vasculopathy is the hallmark of SSc. SSc-associated interstitial lung disease (SSc-ILD) is common and can be associated with poor outcomes, this complication being the leading cause of death in recent series. Because of its huge heterogeneity, SSc-ILD management can be very challenging. Immunosuppressive therapy has long been used to prevent SSc-ILD progression with modest effects in clinical trials. However, thanks to a better understating of SSc pathogenesis, innovative therapies including antifibrotics are increasingly being developed. The achievement of the Safety and Efficacy of Nintedanib in Systemic SClerosIS (SENSCIS) trial has led to the approval by drug agencies of the first antifibrotic drug for SSc-ILD. In parallel, other antifibrotics are being investigated as possible beneficial therapies in SSc-ILD. An important unmet need remains to clarify the positioning of the various strategies, such as the added value of combination of immunosuppressants and antifibrotic therapies in patients at high risk of progression. Indeed, irreversible lung injury or self-perpetuated progression highlights the concept of a window of opportunity in SSc-ILD patients. Herewith, we provide an overview of the most significant clinical trials with antifibrotic drugs developed in recent years for the management of SSc-ILD and a viewpoint about their positioning in treatment algorithms.

Pirfenidone and vitamin D mitigate renal fibrosis induced by doxorubicin in mice with Ehrlich solid tumor

AIMS

Doxorubicin is a prominent anticancer agent. However, its organotoxic potential has restricted its clinical use. The current study was performed to investigate the protective effect of pirfenidone and vitamin D against doxorubicin-triggered nephrotoxicity.

MATERIALS AND METHODS

Female albino mice (5 mice per group) were inoculated with Ehrlish scites carcinoma (EAC) cells for induction of solid tumor and treated with pirfenidone 500 mg/kg orally (p.o.) or vitamin D 0.5 μg/kg intraperitonially (i.p.), either individually or combined with single doxorubicin (15 mg/kg; i.p.) dose. Additionally, 5 mice were served as a normal group. Treatment commenced 7 days after inoculation of Ehrlich ascites carcinoma cells and lasted for 14 days.

KEY FINDINGS

Pirfenidone and vitamin D enhanced the anti-tumor activity of doxorubicin, by decreasing tumor weight and volume. Doxorubicin increased kidney weights, creatinine, urea levels and collagen fibers deposition within renal tubules. Moreover, doxorubicin was associated with overexpression of nuclear factor-kappa B (NF-κB) and alpha-smooth muscle actin (α-SMA) as both parameters assessed by kidney immunohistochemistry. Furthermore, histological signs of large areas of interistital fibrosis and cellular infiltration were significant with sole doxorubicin treatment. Notably, doxorubicin elevated both MCP1 and TGFB1 gene expression in addition to increasing the protein expression of Smad3 and Jun N-terminal Kinase-1 (JNK1) while decreasing that of Smad7. Pirfenidone in combined with vitamin D abolished doxorubicin-evoked disturbances in the aforementioned parameters and blunted all histological alterations.

SIGNIFICANCE

Pirfenidone and vitamin D demonstrated a viable approach to suppress the nephrotoxicity initiated by doxorubicin through inhibiting the JNK1 and MCP-1 pathways.

Overcoming Therapy Resistance and Relapse in TNBC: Emerging Technologies to Target Breast Cancer-Associated Fibroblasts

Breast cancer is the most diagnosed cancer and is the leading cause of cancer mortality in women. Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer. Often, TNBC is not effectively treated due to the lack of specificity of conventional therapies and results in relapse and metastasis. Breast cancer-associated fibroblasts (BCAFs) are the predominant cells that reside in the tumor microenvironment (TME) and regulate tumorigenesis, progression and metastasis, and therapy resistance. BCAFs secrete a wide range of factors, including growth factors, chemokines, and cytokines, some of which have been proved to lead to a poor prognosis and clinical outcomes. This TME component has been emerging as a promising target due to its crucial role in cancer progression and chemotherapy resistance. A number of therapeutic candidates are designed to effectively target BCAFs with a focus on their tumor-promoting properties and tumor immune response. This review explores various agents targeting BCAFs in TNBC, including small molecules, nucleic acid-based agents, antibodies, proteins, and finally, nanoparticles.

[Pirfenidone inhibits proliferation of rabbit tenon fibroblasts by down-regulating TGF-β3 in the TGF-β/Smad pathway]

OBJECTIVE

To investigate the molecular mechanism by which pirfenidone inhibits scar formation through the TGF-β/Smad pathway.

METHODS

Cultured rabbit tenon fibroblasts (RTFs) were treated with different concentrations of pirfenidone to determine its initial active concentration and optimum concentration of pirfenidone for inhibiting RTF proliferation using CCK-8 assay. In RTFs treated with pirfenidone at the initial and optimal concentrations, expressions of TGF-β3, collagen I and collagen III were examined with both immunofluorescence assay and Western blotting, and their mRNA expression levels were detected using RT-PCR.

RESULTS

The initial and optimal concentrations of pirfenidone for inhibiting RTF proliferation were 0.1 mg/mL and 0.27 mg/mL, respectively. In RTFs treated with pirfenidone at the two concentrations for 24 h, both immunofluorescence assay and Western blotting showed significantly lowered protein expressions of TGF-β3, collagen I and collagen III as compared with those in the control group (P < 0.05). The mRNA expressions of TGF-β3, collagen I and collagen III in the RTFs were also significantly lowered after treatment with pirfenidone at the initial and optimal concentrations (P < 0.05).

CONCLUSIONS

Pirfenidone concentration-dependently inhibits the proliferation of RTFs possibly by down-regulating the expression of TGF-β3 in the TGF-β/Smad pathway.

Case Report: Successful Treatment of Refractory Interstitial Lung Disease With Cyclosporine A and Pirfenidone in a Child With SLE

Interstitial lung disease (ILD) as an initial manifestation of lupus is rare, especially in young children. Here, we report a case of a 3-year-old boy who presented with fever, shortness of breath, and facial erythema. Clinical examination suggested a diagnosis of active systemic lupus erythematosus (SLE) with butterfly rash, anemia, positive antinuclear antibody, positive anti-double-stranded DNA, and hypocomplementemia. On retrospective review of the patient’s records, multiple chest computed tomography (CT) images showed non-specific interstitial pneumonia + organizing pneumonia pattern, with no further autoimmune work-up during the visit to a respiratory department. In our opinion, persistent interstitial pneumonia may be a clue to connective tissue disease. The patient received steroid treatment for 1 year, and the radiological and immunological resolution was noted. However, he still suffered from cough and dyspnea. After a 1-year follow-up, he was hospitalized again for SLE relapse. While continuing corticosteroid therapy, the patient was given combination therapy consisting of cyclosporine A (CsA) and monthly-pulse cyclophosphamide for 6 months, and decreased proteinuria was noted. However, the patient’s respiratory symptoms and pulmonary radiologic findings did not improve significantly. With continued steroid therapy, the patient was started on a daily regimen of CsA and pirfenidone. Both drugs were sufficiently effective to allow gradual reduction of steroid dosage. After 2 years of treatment, marked improvements in symptoms, pulmonary function and chest CT images were observed. Our experience with this case emphasizes that prompt work-up for connective tissue disease (CTD) should be considered in young children with ILD, and pirfenidone might be a useful add-on therapy with immunosuppressive agents for refractory CTD-ILD in pediatric patients. Nevertheless, further clinical trials including larger numbers of patients need to assess the efficiency and safety of this combination therapy for refractory CTD-ILD.

Tetraethylthiuram disulphide alleviates pulmonary fibrosis through modulating transforming growth factor-β signalling

Idiopathic pulmonary fibrosis (IPF) induces significant morbidity and mortality, for which there are limited therapeutic options available. Here, we found that tetraethylthiuram disulphide (disulfiram, DSF), a derivative of thiuram, used in the treatment of alcohol abuse, has an inhibitory effect on bleomycin (BLM)-induced pulmonary fibrosis via the attenuation of the fibroblast-to-myofibroblast transition, migration, and proliferation of fibroblasts. Furthermore, DSF inhibited the activation of primary pulmonary fibroblasts and fibroblast cell line under transforming growth factor-β 1 (TGF-β1) challenge. Mechanistically, the anti-fibrotic effect of DSF on fibroblasts depends on the inhibition of TGF-β signalling. We further determined that DSF interrupts the interaction between SMAD3 and TGF-β receptor Ι (TBR Ι), and identified that DSF directly binds with SMAD3, in which Trp326, Thr330, and Cys332 of SMAD3 are critical binding sites for DSF. Collectively, our results reveal a powerful anti-fibrotic function of DSF in pulmonary fibrosis through the inhibition of TGF-β/SMAD signalling in pulmonary fibroblasts, indicating that DSF is a promising therapeutic candidate for IPF.

The TGFβ/Notch axis facilitates Müller cell-to-epithelial transition to ultimately form a chronic glial scar

Background

Contrasting with zebrafish, retinal regeneration from Müller cells (MCs) is largely limited in mammals, where they undergo reactive gliosis that consist of a hypertrophic response and ultimately results in vision loss. Transforming growth factor β (TGFβ) is essential for wound healing, including both scar formation and regeneration. However, targeting TGFβ may affect other physiological mechanisms, owing its pleiotropic nature. The regulation of various cellular activities by TGFβ relies on its interaction with other pathways including Notch. Here, we explore the interplay of TGFβ with Notch and how this regulates MC response to injury in zebrafish and mice. Furthermore, we aimed to characterize potential similarities between murine and human MCs during chronic reactive gliosis.

Methods

Focal damage to photoreceptors was induced with a 532 nm diode laser in TgBAC (gfap:gfap-GFP) zebrafish (ZF) and B6-Tg (Rlbp1-GFP) mice. Transcriptomics, immunofluorescence, and flow cytometry were employed for a comparative analysis of MC response to laser-induced injury between ZF and mouse. The laser-induced injury was paired with pharmacological treatments to inhibit either Notch (DAPT) or TGFβ (Pirfenidone) or TGFβ/Notch interplay (SIS3). To determine if the murine laser-induced injury model translates to the human system, we compared the ensuing MC response to human donors with early retinal degeneration.

Results

Investigations into injury-induced changes in murine MCs revealed TGFβ/Notch interplay during reactive gliosis. We found that TGFβ1/2 and Notch1/2 interact via Smad3 to reprogram murine MCs towards an epithelial lineage and ultimately to form a glial scar. Similar to what we observed in mice, we confirmed the epithelial phenotype of human Müller cells during gliotic response.

Conclusion

The study indicates a pivotal role for TGFβ/Notch interplay in tuning MC stemness during injury response and provides novel insights into the remodeling mechanism during retinal degenerative diseases.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13024-021-00482-z.

The anti-fibrotic drug pirfenidone inhibits liver fibrosis by targeting the small oxidoreductase glutaredoxin-1

Activation of the hepatic stellate cells (HSCs) is a key pathogenic event in liver fibrosis. Protein S-glutathionylation (PSSG) of cysteine residues is a distinct form of oxidative response that modifies protein structures and functions. Glutaredoxin-1 (GLRX) reverses PSSG by liberating glutathione (GSH). In this study, we showed that pirfenidone (PFD), an anti-lung fibrosis drug, inhibited HSC activation and liver fibrosis in a GLRX-dependent manner. Glrx depletion exacerbated liver fibrosis, and decreased GLRX and increased PSSG were observed in fibrotic mouse and human livers. In contrast, overexpression of GLRX inhibited PSSG and liver fibrosis. Mechanistically, the inhibition of HSC activation by GLRX may have been accounted for by deglutathionylation of Smad3, which inhibits Smad3 phosphorylation, leading to the suppression of fibrogenic gene expression. Our results have established GLRX as the therapeutic target of PFD and uncovered an important role of PSSG in liver fibrosis. GLRX/PSSG can be both a biomarker and a therapeutic target for liver fibrosis.

Pirfenidone in heart failure with preserved ejection fraction: a randomized phase 2 trial

In heart failure with preserved ejection fraction (HFpEF), the occurrence of myocardial fibrosis is associated with adverse outcome. Whether pirfenidone, an oral antifibrotic agent without hemodynamic effect, is efficacious and safe for the treatment of HFpEF is unknown. In this double-blind, phase 2 trial ( NCT02932566 ), we enrolled patients with heart failure, an ejection fraction of 45% or higher and elevated levels of natriuretic peptides. Eligible patients underwent cardiovascular magnetic resonance and those with evidence of myocardial fibrosis, defined as a myocardial extracellular volume of 27% or greater, were randomly assigned to receive pirfenidone or placebo for 52 weeks. Forty-seven patients were randomized to each of the pirfenidone and placebo groups. The primary outcome was change in myocardial extracellular volume, from baseline to 52 weeks. In comparison to placebo, pirfenidone reduced myocardial extracellular volume (between-group difference, -1.21%; 95% confidence interval, -2.12 to -0.31; P = 0.009), meeting the predefined primary outcome. Twelve patients (26%) in the pirfenidone group and 14 patients (30%) in the placebo group experienced one or more serious adverse events. The most common adverse events in the pirfenidone group were nausea, insomnia and rash. In conclusion, among patients with HFpEF and myocardial fibrosis, administration of pirfenidone for 52 weeks reduced myocardial fibrosis. The favorable effects of pirfenidone in patients with HFpEF will need to be confirmed in future trials.

Diagnosis and Management of Fibrotic Interstitial Lung Diseases

Nonidiopathic pulmonary fibrosis (non-IPF) progressive fibrotic interstitial lung diseases (PF-ILDs) are a heterogeneous group of ILDs, often challenging to diagnose, although an accurate diagnosis has significant implications for both treatment and prognosis. A subgroup of these patients experiences progressive deterioration in lung function, physical performance, and quality of life after conventional therapy. Risk factors for ILD progression include older age, lower baseline pulmonary function, and a usual interstitial pneumonia pattern. Management of non-IPF P-ILD is both pharmacologic and nonpharmacologic. Antifibrotic drugs, originally approved for IPF, have been considered in patients with other fibrotic ILD subtypes, with favorable results in clinical trials.

Macrophage-mediated degradable gelatin-coated mesoporous silica nanoparticles carrying pirfenidone for the treatment of rat spinal cord injury

The treatment of spinal cord injury is still a challenge worldwide; there is still no effective method. Our strategy is to devise a macrophage-mediated degradable gelatin coated mesoporous silica nanoparticles, which could carry pirfenidone and realize spatiotemporal control of pirfenidone release in the lesion site. For the in vivo experiment, three groups of SD rats subjected to spinal cord contusion injury were injected with GNS-PFD, PFD or PBS. Spinal cord functions were observed. In vitro, we investigated the expression of inflammatory and anti-inflammatory factors. Spinal cord function and recovery were better in the GSN-PFD and PFD than the control group. In the in vitro study, the MMPs after SCI in lesion site were lower in the experimental group. Moreover, the expression of anti-inflammatory and inflammatory factors showed better in the experimental group. The inflammatory response of the PFD to time and space can be achieved with the loading of macrophage-mediated degradable gelatin coated mesoporous silica nanoparticles.

Antifibrotic Therapies and Progressive Fibrosing Interstitial Lung Disease (PF-ILD): Building on INBUILD

Progressive fibrosing interstitial lung disease (PF-ILD) describes a phenotypic subset of interstitial lung diseases characterized by progressive, intractable lung fibrosis. PF-ILD is separate from, but has radiographic, histopathologic, and clinical similarities to idiopathic pulmonary fibrosis. Two antifibrotic medications, nintedanib and pirfenidone, have been approved for use in patients with idiopathic pulmonary fibrosis. Recently completed randomized controlled trials have demonstrated the clinical efficacy of antifibrotic therapy in patients with PF-ILD. The validation of efficacy of antifibrotic therapy in PF-ILD has changed the treatment landscape for all of the fibrotic lung diseases, providing a new treatment pathway and opening the door for combined antifibrotic and immunosuppressant drug therapy to address both the fibrotic and inflammatory components of ILD characterized by mixed pathophysiologic pathways.

Antifibrotic Therapy: Is There a Role in Myositis-Interstitial Lung Disease?

Interstitial lung disease (ILD) is a cause of substantial morbidity and mortality amongst autoimmune diseases, including myositis. Despite first-line therapy with immunosuppression, many inflammatory ILDs advance to a fibrotic stage. In such patients, progressive fibrosis may be amenable to treatment with antifibrotic medications, which were initially studied and approved for the treatment of idiopathic pulmonary fibrosis. We here review the available data that support the use of antifibrotics in connective tissue diseases and progressive fibrosing ILDs. There is now a growing body of evidence in both large randomized clinical trials and on the evolving pathophysiologic pathways to support the use of antifibrotics in select patients with autoimmune ILD and a fibrotic phenotype. Further study of antifibrotics in combination with immunosuppressive medications, and in the myositis-ILD population, is needed.

Antifibrotic Drugs for COVID-19: From Orphan Drugs to Blockbusters?

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Antifibrotic agents are known to treat idiopathic pulmonary fibrosis. The two antifibrotic agents approved and in usage are Pirfenidone and Nintedanib granted by the USFDA in 2014. They are both known to decrease inflammation in the lungs. The fact that COVID-19 has shown to cause inflammation and fibrosis in the lungs frames the theory of their usage in the treatment of the disease by reducing lung scaring and allowing faster discharge of patients with post-COVID complications. The need for them to change their status from orphans to blockbusters has not happened yet due to fewer data and less research available on them as well as various other economic and patient- related factors. Since COVID-19 is widespread and causes many complications of the lungs that are similar to what these two drugs treat. We believe that the status of these drugs could be changed due to an increase in demand for them.

Low-Dose of Intrapulmonary Pirfenidone Improves Human Transforming Growth Factorβ1-Driven Lung Fibrosis

Idiopathic pulmonary fibrosis is a chronic, progressive, and lethal lung disease of unknown etiology. Antifibrotic drugs, including pirfenidone, are currently used for the treatment of the disease. The oral administration of pirfenidone is an effective therapy, as demonstrated by several clinical trials, although it causes severe adverse events in some patients. We hypothesized that low-dose intrapulmonary delivery of pirfenidone is effective in human transforming growth factorβ1-driven pulmonary fibrosis. To demonstrate our hypothesis, we compared the therapeutic efficacy of varying doses of pirfenidone administered by oral and intranasal routes in a human transforming growth factor-β1 transgenic mouse with established pulmonary fibrosis. We found similar amelioration of lung cell infiltration, inflammatory and fibrotic cytokines, lung fibrosis score, and hydroxyproline content in mice with human transforming growth factor-β1-mediated pulmonary fibrosis treated with low-dose intranasal pirfenidone and high-dose oral pirfenidone. This study showed that pirfenidone is a potent inhibitor of human transforming growth factor-β1-driven lung fibrosis and that intrapulmonary delivery of low-dose pirfenidone produces therapeutic responses equivalent to high-dose of oral pirfenidone.

Dual Asymmetric Centrifugation Efficiently Produces a Poloxamer-Based Nanoemulsion Gel for Topical Delivery of Pirfenidone

This study used dual asymmetric centrifugation (DAC) to produce a topical vehicle for Pirfenidone (Pf; 5-methyl-1-phenyl-2[1H]-pyridone)—a Food and Drug Administration-approved antifibrotic drug indicated for idiopathic fibrosis treatment. Pf was loaded (8 wt%) in a poloxamer nanoemulsion gel (PNG) formulation consisting of water (47.8 wt%), triacetin (27.6 wt%), poloxamer 407 (P407, 13.8 wt%), polysorbate 80 (1.8 wt%), and benzyl alcohol (0.9 wt%). To our knowledge, poloxamer gels are typically processed with either high-shear methods or temperature regulation and have not been emulsified using DAC. Using a single-step emulsification process, 2 min mixed at 2500 RPM resulted in the lowest Pf loading variability with a relative standard deviation (RSD) of 0.96% for a 1.5 g batch size. Batch sizes of 15 g and 100 g yield higher RSD of 4.18% and 3.05%, respectively, but still in compliance with USP guidelines. Ex vivo permeation in full thickness porcine skin after 24 h showed total Pf permeation of 404.90 ± 67.07 μg/cm². Tested in vitro on human dermal fibroblasts stimulated with transforming growth factor-beta 1 (TGF-β1), Pf-PNG resulted in a > 2 fold decrease in α-SMA expression over vehicle control demonstrating that formulated Pf retained its biological activity. One-month stability testing at 25°C/60% relative humidity (RH) and 40°C/75% RH showed that % drug content, release kinetics, and biological activity were largely unchanged for both conditions; however, pH decreased from 6.7 to 5.5 (25°C/60% RH) and 4.5 (40°C/75% RH) after 1 month. Overall, these data demonstrate the utility of DAC to rapidly and reproducibly prepare lab-scale batches of emulsified gels for pharmaceutical formulation development.

The effect of pirfenidone on rat chronic prostatitis/chronic pelvic pain syndrome and its mechanisms

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is an intractable problem of the urogenital system. The aetiopathogenesis and effective treatments for CP/CPPS are needed to be untangled. Pirfenidone is a molecule that exhibits anti-inflammatory, antifibrotic, and antioxidative stress capacities in a variety of animal experiments and clinical trials. This study was aimed to investigate the therapeutic effect of pirfenidone on CP/CPPS and to identify the mechanism responsible for it.

METHODS

A CP/CPPS model was induced in rats by intraprostatic injection of complete Freund's adjuvant (CFA). Blood and prostatic tissues were harvested for assessment after the administration of pirfenidone or vehicle for 4 weeks.

RESULTS

The findings revealed that pirfenidone significantly ameliorated chronic pelvic pain and inhibited prostatic inflammation and fibrosis. Further study found that pirfenidone suppressed the expression of proinflammatory mediators, including tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, IL-8. Pirfenidone exhibited a potent antioxidant capacity through improving the activities of glutathione, catalase, total superoxide dismutase, and reducing the production of malondialdehyde. Furthermore, pirfenidone also facilitated the polarization of M2 macrophages and suppressed the activation of the nuclear factor-κB (NF-κB) signaling pathway.

CONCLUSIONS

Pirfenidone can exert a beneficial effect against CFA-induced CP/CPPS by anti-inflammatory, antioxidative, antifibrotic properties, and the function is mediated at least partly through the M2 polarization of macrophages and the inhibition of NF-κB signaling pathway. These findings suggest that pirfenidone holds promise as a potential therapeutic for the treatment of CP/CPPS.

Efficacy of Combination Therapy With Pirfenidone and Low-Dose Cyclophosphamide for Refractory Interstitial Lung Disease Associated With Connective Tissue Disease: A Case-Series of Seven Patients

Objectives

This study reports a low dose combination therapy of cyclophosphamide (CYC) and pirfenidone (PFD) and the efficiency and safety of the therapy in refractory connective tissue disease associated interstitial lung disease (CTD-ILD) patients.

Patients and methods

The study included seven CTD-ILD patients (2 males, 5 females; mean age 48.8 years; range, 32 to 63 years) treated between January 2016 and December 2017 in our clinic. At enrolment, all patients had shown no improvement in their symptoms (dyspnea or cough) after at least one month of high dose steroids treatment. Patients who had received adjusted immunosuppressive agents other than steroids or anti-fibrotic medications within the three months before enrolment were excluded. We changed the treatment to a low dose combination of CYC 0.4 g/m2 monthly and PFD 300 mg twice per day and quickly reduced the steroids. All the patients were followed-up for 12 months.

Results

Two patients had anti-synthetase syndrome, two had Sjögren syndrome, two had scleroderma and one had mixed connective tissue disease. The baseline forced vital capacity (FVC) was 39-81% and the six-minute walk distance (6MWD) was 202 m-324 m. Within 12 months follow-up, the median improvement in the FVC was 13.4% (range, 0-35.9%), the median improvement of carbon monoxide diffusing capacity was 6.3% (range, 1.7-16%) and the median improvement of 6MWD was 52.7% (range, 34.4-86.3%). All the patients were self-sufficient, and their dyspnea, chest high- resolution computed tomography scores, and quality of life improved simultaneously. Exceeding our expectations, no adverse events associated with CYC or PFD were observed during the follow-up period.

Conclusion

Our study provided preliminary while promising clinical evidence for combination therapy of CYC-PFD for CTD-ILD. A low dose combination of CYC and PFD was unexpectedly well tolerated, with satisfactory effects in refractory CTD-ILD patients. Well-designed controlled studies are needed to further establish the safety and efficacy of this approach.

Benefits of prolonged-release pirfenidone plus standard of care treatment in patients with advanced liver fibrosis: PROMETEO study

Background and aims

Pirfenidone (PFD), an oral antifibrotic drug, has been authorized by the EMA and FDA for treatment of idiopathic pulmonary fibrosis. Few studies have addressed its use in advanced liver fibrosis (ALF). We evaluated a prolonged-release formulation (PR-PFD) plus standard of care on disease progression in ALF.

Methods

281 ALF patients from 12 centers receiving PR-PFD (600 mg bid) were screened; 122 completed 1 year of treatment. Additionally, 74 patients received only standard of care regimen. Average age was 64 ± 12 years, 58% female. 43.5% had fatty liver disease (NAFLD), 22.5% viral hepatitis C (VHC), 17% autoimmune hepatitis (AIH), and 17% alcoholic liver disease (ALD). Baseline fibrosis was F4 in 74% and F3 in 26%. Antifibrotic effects were assessed by transient elastography (Fibroscan^®) and Fibro Test^® (FT); Cytokines and PFD plasma levels were tracked and quality of life evaluated.

Results

We found a significant reduction in fibrosis in 35% of PR-PFD patients and only in 4.1% in non PR-PFD patients. Child–Pugh score improved in 29.7%. Biochemical values remained stable; 40.6% and 43.3% decreased ALT or AST, respectively. TGFβ1 (pg/mL) levels were lower in PFD-treated patients. PFD serum concentration (µg/mL) was higher (8.2 ± 1.7) in fibrosis regression profile (FRP) patients compared to fibrosis progression profile (FPP) patients (4.7 ± 0.3 µg/mL, p < 0.01). 12% reported transient burning or nausea and 7% photosensitivity. Quality of life (Euro-Qol scale) improved from 62 ± 5 to 84 ± 3 (p < 0.001) and from 32 ± 3 to 42 ± 2 (p < 0.008) (FACIT scale).

Conclusions

PR-PFD is efficacious and safe in ALF and associated with promising antifibrotic effects.

Trial registration

Clinical trial number: NCT04099407.

The extended utility of antifibrotic therapy in progressive fibrosing interstitial lung disease

INTRODUCTION

The approval of two antifibrotic treatment agents for delaying disease progression in idiopathic pulmonary fibrosis (IPF), has prompted researchers to look at expanding the role of antifibrotic therapy to other fibrosing interstitial lung disease (ILD). Similarities in the pathological mechanisms that lead to the development of IPF have been implicated in other progressive fibrosing ILD (PF-ILD) such as chronic hypersensitivity pneumonitis, connective tissues disease associated ILD, sarcoidosis, occupational ILD and idiopathic non-specific interstitial pneumonia (iNSIP). This has prompted the rationale to use antifibrotic therapy to target similar molecular pathways in these diseases.

AREAS COVERED

This review will summarise the available evidence from randomised controlled trials that have evaluated the use of antifibrotic therapy in PF-ILD outside the realm of IPF.

EXPERT OPINION

There is promising data for antifibrotic therapy as a therapeutic option for non IPF PF-ILD. The new therapy option does provide some challenges that need to be addressed such as timing of initiation of therapy, clarifying the strategy for overlap or combination with existing immunosuppressive therapies and potential drug interactions. There is an unmet need to determine accurate predictors of disease progression to allow early intervention for the preservation of lung function and mortality reduction.

Idiopathic Pulmonary Fibrosis: A Review of Disease, Pharmacological, and Nonpharmacological Strategies With a Focus on Symptoms, Function, and Health-Related Quality of Life

Despite several advances in treatment, idiopathic pulmonary fibrosis (IPF) remains a progressive, symptomatic, and terminal disease in patients not suitable for lung transplantation. With disease progression, IPF often leads to a constellation of symptoms, including dyspnea, cough, anxiety, and depression. Palliative care is appropriate to support these patients. However, traditional curriculum in palliative care has often focused on supporting patients with malignant disease, and clinicians are not universally trained to manage patients with progressive nonmalignant diseases such as IPF. Current antifibrotic therapies aim to slow disease progression but are not able to reduce symptoms or improve daily function and health-related quality of life (HRQL). Palliative care in this patient group requires an understanding of the clinical characteristics of IPF, comorbidities, common medications used, and nonpharmacological strategies that can be undertaken to improve daily function and HRQL. This review focuses on IPF management strategies and their effects on symptoms, exercise tolerance, HRQL, and survival. Pharmacological interactions and considerations related to commonly used palliative care medications are also reviewed. This review highlights the needs of patients with IPF and caregivers, psychosocial function, patient-reported assessment tools, and topics related to advance care planning.

The profibrotic effects of chronic microaspiration of bile acids on lungs of rats at different stages

This study aimed to explore the profibrotic effects of chronic microaspiration of two major bile acids, including chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA), on lungs of rats at different stages, as well as the underlying mechanisms in vivo. A rat model was induced by weekly intratracheal instillation of DCA and CDCA. Our results showed that chronic microaspiration of bile acids resulted in alveolar structure disorder, and inflammatory cells infiltration in the pulmonary interstitium at the early stage. Subsequently, numerous fibroblasts were proliferated, and collagen deposition was profoundly increased over the interstitium of the airways and vessels. Compared with control group, the expression of α-smooth muscle actin, type I collagen, hydroxyproline, transforming growth factor-β1 (TGF-β1), and matrix metalloproteinase-9 in the lung tissues were remarkably elevated at the 2nd week, reached the highest level at the 6th week, and maintained high at the 8th week in both DCA- and CDCA-treated groups (P < 0.05). Furthermore, chronic microaspiration of bile acids led to higher levels of glutathione and malondialdehyde, while lower level of superoxide dismutase in lung tissues compared with controls (P < 0.05), thereby resulting in the oxidant/antioxidant enzyme imbalance in the formation of fibrosis. In addition, we also found a consistent growth in the expression of farnesoid X receptor (FXR) in both DCA- and CDCA-treated groups. Our findings suggested that chronic microaspiration of bile acids could initiate the process of pulmonary fibrosis from the early phase and promote its progression in a time-dependent manner, which likely involved the TGF-β1, oxidative stress, and FXR-related pathways.

Repurposing Pirfenidone for Nonalcoholic Steatohepatitis-related Cirrhosis: A Case Series

We repurposed the antifibrotic drug pirfenidone-which is approved for treatment of idiopathic lung fibrosis-in a series of patients with nonalcoholic steatohepatitis-related cirrhosis. Our report demonstrates the observed improvements in necroinflammation and regression of cirrhosis with pirfenidone use for 12-weeks, associated with classical hepatic repair complex features on follow-up liver biopsies. This novel work could help stimulate further randomized trials of pirfenidone in patients with nonalcoholic steatohepatitis-related liver fibrosis or cirrhosis, for whom no recommended drug treatments exists currently.

Efficacy and Safety of Pirfenidone in Patients with Second-Degree Burns: A Proof-of-Concept Randomized Controlled Trial

OBJECTIVE

Several studies suggest that pirfenidone may have a potential off-label use for wound healing. However, the effectiveness of this medication in patients with burns remains uncertain. Accordingly, investigators sought to assess wound re-epithelialization in patients with second-degree burns after adding pirfenidone to usual care.

DESIGN AND SETTING

Single-center pilot, proof-of-concept, single-blind randomized controlled trial.

PATIENTS AND INTERVENTION

Eight patients with second-degree burns were treated with occlusive hydrocolloid dressings and were randomly allocated to receive either no additional treatment or pirfenidone.

OUTCOME MEASURES

The primary outcome of the study was to evaluate wound healing between groups based on the thickness of the re-epithelialized epidermis at day 7. Secondary outcomes were to qualitatively assess the development of fibrotic tissue in the dermis, anomalies in the basal membrane, and the development of collagen fibers by histologic analysis. Liver and renal functions were measured daily to assess the overall safety of oral pirfenidone.

MAIN RESULTS

Patients treated with pirfenidone showed a remarkable improvement in wound re-epithelialization at day 7 (148.98 ± 13.64 vs 119.27 ± 15.55 μm; P = .029; 95% confidence interval, 4.14-55.29). Histologic evaluations showed less wound fibrosis in the pirfenidone group.

CONCLUSIONS

A decrease in wound healing time by enhancing wound re-epithelialization was observed with pirfenidone. Larger clinical trials are needed to reach more reliable conclusions.

Mitigating fibrosis-An impediment to corneal re-innervation following lamellar flap surgery

Restoration of corneal sensitivity is of utmost importance to maintain corneal homeostasis following any injury or insult, for which, both corneal nerve regeneration and re-innervation are essential. Fibrosis poses a major impediment for re-innervation. We have in this study evaluated the influence of various nerve growth factors and corneal fibrosis on corneal nerve regeneration and reinnervation following lamellar flap surgery (LFS) and its modulation using antifibrotic drug pirfenidone. To achieve this, trigeminal ganglion cells were treated with pirfenidone, NGF, and NT-3 to evaluate their effect on trigeminal cell neurite growth. Following LFS, the gene expression of nerve growth factors NGF, BDNF and NT-3, Gap 43, Nogo-A and profibrotic factors Tenascin C, TGF-beta 1 were evaluated with and without pirfenidone. Wound fibrosis and corneal nerve regeneration using pirfenidone following LFS were evaluated by staining whole corneal mounts with α SMA and β tubulin 3. Safety of NGF and pirfenidone topical drops in normal unoperated cornea and its efficacy in enhancing corneal healing was evaluated following LFS. Our study shows, pirfenidone did not influence trigeminal cell neurite elongation; NGF and NT-3 significantly enhanced trigeminal cell neurite elongation. NT-3 also significantly increased neurite branching. There was significant increase in the gene expression of NGF, BDNF, NT-3, Gap- 43, TGF beta-1, Tenascin C, Nogo-A genes in the operated cornea compared to normal cornea, treatment of operated corneas with pirfenidone prevented the increased expression of these genes except Gap 43 which remained unchanged. The treatment of operated eyes with combination of NGF and pirfenidone positively influenced corneal healing compared to treatment with NGF alone, and had no adverse influence on the cornea. Pirfenidone appreciably reduced corneal fibrosis which aided in re-innervation. Both NGF and NT3 positively influence trigeminal neurite elongation. NGF and pirfenidone have complementary influence on corneal wound healing.

A new FGFR inhibitor disrupts the TGF-β1-induced fibrotic process

Pulmonary fibrosis (PF) is chronic and irreversible damage to the lung characterized by fibroblast activation and matrix deposition. Although recently approved novel anti‐fibrotic agents can improve the lung function and survival of patients with PF, the overall outcomes remain poor. In this study, a novel imidazopurine compound, 3‐(2‐chloro‐6‐fluorobenzyl)‐1,6,7‐trimethyl‐1H‐imidazo[2,1‐f]purine‐2,4(3H,8H)‐dione (IM‐1918), markedly inhibited transforming growth factor (TGF)‐β‐stimulated reporter activity and reduced the expression of representative fibrotic markers, such as connective tissue growth factor, fibronectin, collagen and α‐smooth muscle actin, on human lung fibroblasts. However, IM‐1918 neither decreased Smad‐2 and Smad‐3 nor affected p38MAPK and JNK. Instead, IM‐1918 reduced Akt and extracellular signal‐regulated kinase 1/2 phosphorylation increased by TGF‐β. Additionally, IM‐1918 inhibited the phosphorylation of fibroblast growth factor receptors 1 and 3. In a bleomycin‐induced murine lung fibrosis model, IM‐1918 profoundly reduced fibrotic areas and decreased collagen and α‐smooth muscle actin accumulation. These results suggest that IM‐1918 can be applied to treat lung fibrosis.

Pirfenidone attenuates the profibrotic contractile phenotype of differentiated human dermal myofibroblasts

Dysregulated wound healing after burn injury frequently results in debilitating hypertrophic scarring and contractures. Myofibroblasts, the main effector cells for dermal fibrosis, develop from normal fibroblasts via transforming growth factor beta 1 (TGF-β1). During wound healing, myofibroblasts produce extracellular matrix (ECM) proteins, modulate ECM stability, and contract the ECM using alpha smooth muscle actin (α-SMA) in contractile stress fibers. The antifibrotic pirfenidone has previously been shown to inhibit the initial differentiation of fibroblasts into myofibroblasts in vitro and act as a prophylactic measure against hypertrophic scar development in a mouse burn model. To test whether pirfenidone affects differentiated myofibroblasts, we investigated the in vitro effects of pirfenidone treatment after three to five days of stimulation with TGF-β1. In assays for morphology, protein and gene expression, and contractility, pirfenidone treatment produced significant effects. Profibrotic gene expression returned to near-normal levels, further α-SMA protein expression was prevented, and cell contraction within a stressed collagen matrix was reduced. These in vitro results promote pirfenidone as a promising antifibrotic agent to treat existing scars and healing wounds by mitigating the effects of differentiated myofibroblasts.

FFNT25 ameliorates unilateral ureteral obstruction-induced renal fibrosis

Renal fibrosis is a common pathological feature of chronic kidney disease (CKD) patients who progress to end-stage renal disease (ESRD). With the increasing incidence of CKD, it is of importance to develop effective therapies that blunt development of renal fibrosis. FFNT25 is a newly developed molecular compound that could be used to prevent fibrosis. In this study, we administered FFNT25 to rats following unilateral ureteral obstruction (UUO) to investigate its anti-fibrosis mechanism. Thirty-two Sprague-Dawley rats were randomly divided into four groups: (1) control (normal rats), (2) sham-operated, (3) UUO-operated + vehicle, and (4) UUO-operated + FFNT25. Two weeks after UUO, the rats were gavaged with either FFNT25 (20.6 mg/kg/day) or vehicle for two weeks. Serum, urine, and kidney samples were collected at the end of the study. FFNT25 reduced levels of renal fibrosis and decreased mRNA and protein levels of extracellular matrix (ECM) markers α-smooth muscle actin (α-SMA) and plasminogen activator inhibitor-1 (PAI-1) following UUO compared to vehicle treatment (n = 8, p<.05). The current results indicate that FFNT25 can affect both the production and degradation of collagen fibers to reduce fibrosis.

Antifibrotic therapy for fibrotic lung disease beyond idiopathic pulmonary fibrosis

Two antifibrotic medications (nintedanib and pirfenidone) were recommended (conditionally) for the treatment of patients with idiopathic pulmonary fibrosis (IPF) in the 2015 IPF evidence-based guidelines. These medications have been shown to reduce the rate of decline in forced vital capacity among patients with IPF over time and are the only two disease-modulating pharmacological agents approved by regulatory agencies and available for clinical use worldwide. With the evolved standard of care for interstitial lung disease evaluation including routine use of high-resolution computed tomography, fibrotic lung diseases other than IPF are increasingly recognised. In addition, it is becoming evident that genetic and pathophysiological mechanisms as well as disease behaviour in patients manifesting other "non-IPF progressive fibrotic interstitial lung diseases" (non-IPF-PF) may be similar to those in patients with IPF. Thus, it is biologically plausible that pharmacological agents with antifibrotic properties may be efficacious in non-IPF-PF. Indeed, studies are underway or planned to assess the safety and efficacy of nintedanib or pirfenidone among patients with several non-IPF fibrotic lung diseases. In this review, we briefly summarise the use of pirfenidone and nintedanib in IPF as well as the rationale and potential for use of these medications in non-IPF-PF that are being investigated in ongoing and upcoming clinical trials.

Protective role of pirfenidone against experimentally-induced pancreatitis

BACKGROUND

Pirfenidone (PFD) is an orally active antifibrotic agent that has anti-inflammatory activity in diverse animal models. Its effect against acute pancreatitis (AP) has not been elucidated. Hence, the present investigation was carried out to assess the potential protective role of PFD against l-arginine-induced AP in mice.

METHODS

AP was induced in adult male Swiss albino mice via intraperitoneal injections of l-arginine (4 g/kg, twice each 1 h apart). PFD (250 mg/kg, orally) was administered one day before and on the day of l-arginine challenge. Twenty-four hours after l-arginine injection, the severity of AP was evaluated using biochemical and histological analyses. Indices of oxidative stress, inflammation and apoptosis were evaluated using ELISA and immunohistochemistry (IHC).

RESULTS

PFD suppressed the development of l-arginine-induced AP as revealed by the improvement of histopathological lesions of pancreatic specimen and the significant reduction of serum amylase and lipase levels. Notably, PFD reduced the lipid peroxidation and enhanced the antioxidants such as reduced glutathione (GSH) and superoxide dismutase (SOD) in pancreatic tissue. Importantly, PFD suppressed AP-associated elevation of inflammatory cytokines along with depression of nuclear factor kappa-B (NF-κB) immuno-expression in pancreatic tissue. Lastly, PFD efficiently ameliorated AP-induced elevation of the pro-apoptotic protein (Bax) and increased AP-induced reduction of the anti-apoptotic protein (Bcl2).

CONCLUSIONS

PFD protected against l-arginine-induced AP in mice through anti-oxidative, anti-inflammatory and anti-apoptotic properties.

Perils with Pirfenidone and "the tuberculosis link"

We report a case of idiopathic pulmonary fibrosis (IPF) treated with pirfenidone who developed tuberculosis (TB) and later had exfoliative dermatitis secondary to an interaction between pirfenidone and rifampicin. This case report highlights the possible risk of developing TB in patients diagnosed with IPF and on antifibrotic therapy like pirfenidone. Furthermore, this case report documents a previously unreported adverse reaction due to the interaction of rifampicin with pirfenidone.

Effect of pirfenidone injection on ferret vocal fold scars: A preliminary in vivo study

OBJECTIVES

This study examined the antifibrotic effect of pirfenidone (PFD), which has received regulatory approval in the United States and Japan for treatment of idiopathic pulmonary fibrosis, on the scarred ferret vocal fold (VF) in vivo.

METHODS

Eight male ferrets were divided into two groups: saline and PFD. All animals underwent unilateral scarring under anesthesia. The right VF was electrocauterized with ablation of the entire lamina propria. PFD (1.0 mg/mL) or saline injections into right-side scarred VFs were performed (under an operating microscope) 4 weeks later. After an additional 4 weeks, the larynges were harvested for histological analysis. Prior to harvesting, the ferrets were re-anesthetized, and the VFs were observed and recorded using a rigid video laryngoscope. We immunohistochemically evaluated the expression of collagen types I and III, alpha-smooth muscle actin (α-SMA), and fibronectin in the entire lamina propria. We compared the affected areas (calculated using ImageJ software) between the treated (right) and untreated (left) sides within the same animals and between groups.

RESULTS

Collagen type I (P = 0.0021) and α-SMA (P = 0.0021) expression levels were lower in the PFD group, but the collagen type III and fibronectin levels did not differ significantly between the two groups.

CONCLUSION

PFD injection into the scarred VF is a potentially promising novel antifibrotic treatment.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:726-731, 2020.

Pathophysiology of Fibrosis in the Vocal Fold: Current Research, Future Treatment Strategies, and Obstacles to Restoring Vocal Fold Pliability

Communication by voice depends on symmetrical vibrations within the vocal folds (VFs) and is indispensable for various occupations. VF scarring is one of the main reasons for permanent dysphonia and results from injury to the unique layered structure of the VFs. The increased collagen and decreased hyaluronic acid within VF scars lead to a loss of pliability of the VFs and significantly decreases their capacity to vibrate. As there is currently no definitive treatment for VF scarring, regenerative medicine and tissue engineering have become increasingly important research areas within otolaryngology. Several recent reviews have described the problem of VF scarring and various possible solutions, including tissue engineered cells and tissues, biomaterial implants, stem cells, growth factors, anti-inflammatory cytokines antifibrotic agents. Despite considerable research progress, these technical advances have not been established as routine clinical procedures. This review focuses on emerging techniques for restoring VF pliability using various approaches. We discuss our studies on interactions among adipose-derived stem/stromal cells, antifibrotic agents, and VF fibroblasts using an in vitro model. We also identify some obstacles to advances in research.

Tissue engineering strategies combining molecular targets against inflammation and fibrosis, and umbilical cord blood stem cells to improve hampered muscle and skin regeneration following cleft repair

Cleft lip with or without cleft palate is a congenital deformity that occurs in about 1 of 700 newborns, affecting the dentition, bone, skin, muscles and mucosa in the orofacial region. A cleft can give rise to problems with maxillofacial growth, dental development, speech, and eating, and can also cause hearing impairment. Surgical repair of the lip may lead to impaired regeneration of muscle and skin, fibrosis, and scar formation. This may result in hampered facial growth and dental development affecting oral function and lip and nose esthetics. Therefore, secondary surgery to correct the scar is often indicated. We will discuss the molecular and cellular pathways involved in facial and lip myogenesis, muscle anatomy in the normal and cleft lip, and complications following surgery. The aim of this review is to outline a novel molecular and cellular strategy to improve musculature and skin regeneration and to reduce scar formation following cleft repair. Orofacial clefting can be diagnosed in the fetus through prenatal ultrasound screening and allows planning for the harvesting of umbilical cord blood stem cells upon birth. Tissue engineering techniques using these cord blood stem cells and molecular targeting of inflammation and fibrosis during surgery may promote tissue regeneration. We expect that this novel strategy improves both muscle and skin regeneration, resulting in better function and esthetics after cleft repair.

CXCR4-targeted liposomal mediated co-delivery of pirfenidone and AMD3100 for the treatment of TGFβ-induced HSC-T6 cells activation

Background: Liver fibrosis is a chronic liver disease associated with an excessive accumulation of extracellualr matrix (ECM) proteins which ultimately lead to cirrohosis and hepatocellular carcinoma.

Purpose: Liver fibrosis therapies that use combination approaches with the ability to affect multiple disease pathways have proven higher efficacies. This study aimed at optimizing and characterizing the co-encapsulation of pirfenidone (PF) and AMD3100 (AMD) into CXCR4-targeted combination liposomes (CTC liposome) for CXCR4 targeting, and the inhibition of major molecular culprits ie α-SMA, CXCR4, TGFβ, and P-p38 involved in liver fibrosis in-vitro.

Methods: The CTC liposomes were prepared using the thin-film hydration method. The concentration of encapsulated AMD and PF was measured by HPLC and UV spectrophotometry, respectively. Tramsmission electron microscopy (TEM) was used to determine the liposomal morphology. The CXCR4 targeting ability was determined by CXCR4 redistribution assay. Confocal microscopy and flowcytometry were used to determine the CXCR4 mediated cell uptake. The apoptosis inducing and protein downreguating ability of CTC liposomes were determined by apoptosis assay and western blot analysis, respectively. In-vivo biodistribution and Hoechst staining were used to confirm the feasibility of CTC liposome for the in-vivo applications and drug targeted accumulation, respectively.

Results: The TEM studies revealed that CTC liposomes were spherical in shape. The cumulative release of AMD and PF from CTC liposome was 67% and 84%, respectively, at 48 h. Compared to the free drug counterparts, encapsulated drugs displayed higher cell viability. The CXCR4 redistribution assay confirmed the CXCR4 targeting and antagonistic ability of CTC liposomes. The CTC liposomes were internalized more effectively via caveolae-mediated endocytic pathways. CTC liposomes displayed aggressive apoptosis (87.3%) in TGFβ-induced activated HSC-T6 cells suggesting a propensity to fibrosis regression. Also, CTC liposomes significantly reduced α-SMA (65%), CXCR4 (77%), TGFβ (89%), and P-p38 (66%) expressions, better than free drugs. CTC@IR780 liposomes (CTC liposomes incorporating IR780 dye) were more accumulated in fibrotic livers compared to free IR780, as judged by in-vivo imaging, biodistribution analysis, and Hoechst staining. These findings suggest that this simple and stable CTC liposomal system holds a great promise for the treatment and prevention of liver fibrosis.