Potential Rheumatoid Arthritis-Associated Interstitial Lung Disease Treatment and Computational Approach for Future Drug Development.

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by swelling in at least one joint. Owing to an overactive immune response, extra-articular manifestations are observed in certain cases, with interstitial lung disease (ILD) being the most common. Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is characterized by chronic inflammation of the interstitial space, which causes fibrosis and the scarring of lung tissue. Controlling inflammation and pulmonary fibrosis in RA-ILD is important because they are associated with high morbidity and mortality. Pirfenidone and nintedanib are specific drugs against idiopathic pulmonary fibrosis and showed efficacy against RA-ILD in several clinical trials. Immunosuppressants and disease-modifying antirheumatic drugs (DMARDs) with anti-fibrotic effects have also been used to treat RA-ILD. Immunosuppressants moderate the overexpression of cytokines and immune cells to reduce pulmonary damage and slow the progression of fibrosis. DMARDs with mild anti-fibrotic effects target specific fibrotic pathways to regulate fibrogenic cellular activity, extracellular matrix homeostasis, and oxidative stress levels. Therefore, specific medications are required to effectively treat RA-ILD. In this review, the commonly used RA-ILD treatments are discussed based on their molecular mechanisms and clinical trial results. In addition, a computational approach is proposed to develop specific drugs for RA-ILD.

Statins' still controversial role in pulmonary fibrosis: What does the evidence show?

Pulmonary fibrosis (PF) represents the end stage of a broad range of interstitial lung diseases (ILDs). Statins are among the compounds which have been implicated in drug-induced ILD development. However, recent studies (both in vitro and in vivo) have provided evidence that statins may exert anti-inflammatory and anti-fibrotic effects potentially offering benefits to patients with PF. Several protective molecular mechanisms including the suppression of mevalonic acid pathway, the inhibition of NADPH oxidase activation in macrophages and the inhibition of several profibrotic mediators have been proposed to explain the observed in vivo decrease of the oxidative stress in the lung and the preservation of lung function in patients. Earlier clinical studies relating statins with drug-induced ILD development are contradicted by increasing new data showing the beneficial effects of statins in clinical outcomes in ILD patients who receive statins for concomitant cardiovascular indications. Future research may further elucidate the wide spectrum of pathways of IPF pathogenesis, and genetic heterogeneity, identifying clinically applicable biomarkers and specific endotypes thus recognizing in which patients statins could confer benefit and in which they might cause detrimental effects.

Novel targeted therapies for the management of liver fibrosis.

Introduction: Prolonged liver injury results in tissue damage and replacement by extracellular matrix and fibrosis. Cirrhosis represents a leading cause of mortality worldwide and imposes a major financial burden on health-care systems. Fortunately, fibrogenesis has proven to be reversible if halted early, encouraging the development of novel anti-fibrotic agents that may accelerate histological restoration. Preclinical data have elucidated numerous potential therapeutic targets and many anti-fibrotic agents are currently at various stages of clinical research.Areas covered: The present review summarizes recent clinical data regarding anti-fibrotic drugs including monoclonal antibodies, targeted conjugates, and small molecule agents.Expert opinion: Although undeniable progress has been made in the development of anti-fibrotic agents in recent years, most data currently available are derived from preclinical and early clinical studies. The efficacy and safety of these agents will need to be corroborated by larger clinical trials, some of which are ongoing with results expected in the upcoming years. Combination therapy with agents targeting different pathways of fibrogenesis will also be of great interest for the future and will need to be explored in clinical trials.

Therapeutic burden in interstitial lung disease: Lessons to learn.

BACKGROUND AND OBJECTIVE: Patients with interstitial lung disease (ILD) are often prescribed disease-targeted and symptomatic therapies, both of which can cause significant treatment burden due to polypharmacy and drug-disease interactions. This study aimed to evaluate medication regimen complexity before and after introduction of ILD-specific therapies. Potential drug-disease interactions were evaluated for patients who were prescribed prednisolone. METHODS: In this study, 214 patients with ILD were assessed for demographic information, co-morbidities and medication use. Medication lists were reviewed prior to and after the introduction of ILD-specific therapies. Complexity of treatment regimen was examined using the validated Medication Regimen Complexity Index (MRCI). RESULTS: Of the 214 patients, 75 had idiopathic pulmonary fibrosis (IPF) while the rest had inflammatory ILD (chronic hypersensitivity pneumonitis: 45; connective tissue disease-related ILD: 41). Polypharmacy was common at baseline (IPF: 51%, inflammatory ILD: 63%). Following introduction of ILD-specific therapies, median total MRCI scores significantly increased from 8 (interquartile range (IQR) = 8-15) to 22.5 (17.5-27.5) and 14.5 (8.5-21) to 21.5 (16-30) for IPF and inflammatory ILD groups, respectively (P < 0.0001 for both). Complex dosing instructions contributed the most to total MRCI scores for ILD-specific therapies. Among patients receiving prednisolone (n = 113), 88% had ≥1 co-morbidity which may be impacted. Common co-morbidities included gastrointestinal diseases (56%), obesity (37%), osteoporosis (24%) and diabetes mellitus (18%). CONCLUSION: Polypharmacy and complex medication regimen are common in patients with ILD of different aetiologies. There is a high frequency of potential drug-disease interactions among patients who are prescribed systemic corticosteroids. These findings highlight the need for careful evaluation of the impact of therapeutic complexity and burden in patients with ILD.

What can target kidney fibrosis?

Fibrosis, a characteristic of all chronic kidney diseases, is now recognized to be an independent predictor of disease progression. Deposition of pathological matrix in the walls of glomerular capillaries, the interstitial space and around arterioles both predicts and contributes to functional demise of the nephron and its surrounding vasculature. Recent identification of the major cell populations of fibroblast precursors in the kidney interstitium as pericytes and tissue-resident mesenchymal stem cells, and in the glomerulus as podocytes, parietal epithelial and mesangial cells, has enabled the study of the fibrogenic process in much greater depth directly in the fibroblast precursors. These cells are not only matrix-producing cells, but are also important innate immune surveillance cells that regulate the inflammatory process, exacerbate tissue damage by release of radicals and cytokines, and contribute to parenchymal and microvascular dysfunction by aberrant wound-healing responses. Innate immune signaling in fibroblasts and their precursors is intimately intertwined with the process of fibrogenesis. In addition, genomic and genetic studies also point to defective responses in loci close to genes involved in solute transport, metabolism, autophagy, protein handling and vascular homeostasis, principally in the epithelium and endothelium, as upstream drivers of the fibrotic process, indicating that cellular crosstalk is vital for development of fibrosis. As we move beyond TGFß inhibition as a central target for fibrosis, targeting innate immune signaling and metabolic dysfunction appear increasingly tenable alternative targets for novel therapies.

Factors Affecting Best-Tolerated Dose of Pirfenidone in Patients with Fibrosing Interstitial Lung Disease.

The aim of the study was to examine the best-tolerated dose of pirfenidone, the adverse effects profile, and potential factors other than drug dose influencing the tolerability of pirfenidone in patients with fibrosing interstitial lung diseases (ILDs). We performed an observational retrospective study of 113 patients with IPF and other fibrosing ILDs treated with pirfenidone. Baseline liver function tests (LFTs) and dose escalation of pirfenidone were recorded for all patients. The best-tolerated dose was continued if the patient did not tolerate full dose (2400 mg) despite repeated dose escalation attempts. Potential risk factors such as age, height, weight, body mass index (BMI), body surface area (BSA), gender, smoking, and presence of comorbidities were analyzed between 3 groups of best-tolerated pirfenidone doses: 2400 mg/day vs. <2400 mg/day, 2400 mg/day vs. 1800 mg/day, and 2400 mg/day vs. 1200 mg/day. A total of 24 patients tolerated 2400 mg/day, and 89 patients tolerated <2400 mg/day (43 tolerated 1800 mg/day, 45 tolerated 1200 mg/day and 1 tolerated 600 mg/day). Patients who tolerated 2400 mg/day were taller and had a larger BSA as compared to those tolerating <2400 mg/day. Overall, males tolerated the drug better. Presence of comorbidities or smoking did not affect the tolerance of pirfenidone, except for the presence of cerebrovascular diseases. Various adverse effects did not have any significantly different frequencies between the compared groups. Moreover, 71.7% of patients experienced at least one side effect. 1200 mg/day was the best-tolerated dose in the majority of the patients. Male patients with a larger BSA and greater height showed better tolerability of pirfenidone overall.

Pharmacological management of systemic sclerosis associated interstitial lung disease.

INTRODUCTION: Interstitial lung disease (ILD) is a major cause of disease-related morbidity and one of the leading causes of mortality in patients with systemic sclerosis (SSc). Many patients will be diagnosed with SSc before the emergence of clinically meaningful ILD. Screening and early recognition of SSc-ILD allows prompt intervention and improved clinical outcomes. In recent years, clinical trial data from large well-designed randomized controlled trials have greatly enhanced our understanding of the natural history of SSc-ILD and risk factors for progressive disease. These advances have led to the emergence of treatment paradigms designed to address the management of both established and subclinical disease. AREAS COVERED: The present review shall consider the findings of recent trials and implications for modern pharmacological management of SSc-ILD. Where relevant, knowledge gaps shall be highlighted to outline the potential focus of additional research in this field. EXPERT OPINION: Recent clinical trial data have confirmed beyond doubt the value of immunomodulatory treatment in SSc-ILD, and it is expected this shall translate into improved clinical outcomes in SSc-ILD. We need better methods of cohort enrichment for SSc-ILD clinical trials, and biomarker discovery may establish molecular signatures allowing more personalized approaches to SSc-ILD prevention and management.

A drug-responsive multicellular human spheroid model to recapitulate drug-induced pulmonary fibrosis.

Associated with a high mortality rate, pulmonary fibrosis (PF) is the end stage of several interstitial lung diseases. Although many factors are linked to PF progression, initiation of the fibrotic process remains to be studied. Current research focused on generating new strategies to gain a better understanding of the underlying disease mechanism as the animal models remain insufficient to reflect human physiology. Herein, to account complex cellular interactions within the fibrotic tissue, a multicellular spheroid model where human bronchial epithelial cells incorporated with human lung fibroblasts was generated and treated with bleomycin (BLM) to emulate drug-induced PF. Recapitulating the epithelial-interstitial microenvironment, the findings successfully reflected the PF disease, where excessive alpha smooth muscle actin and collagen type I secretion were noted along with the morphological changes in response to BLM. Moreover, increased levels of fibrotic linked COL13A1, MMP2, WNT3 and decreased expression level of CDH1 provide evidence for the model reliability on fibrosis modelling. Subsequent administration of the Food and Drug Administration approved nintedanib and pirfenidone anti-fibrotic drugs proved the drug-responsiveness of the model.

Inhibition of CHIT1 as a novel therapeutic approach in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive and eventually fatal lung disease with a complex etiology. Approved drugs, nintedanib and pirfenidone, modify disease progression, but IPF remains incurable and there is an urgent need for new therapies. We identified chitotriosidase (CHIT1) as new driver of fibrosis in IPF and a novel therapeutic target. We demonstrate that CHIT1 activity and expression are significantly increased in serum (3-fold) and induced sputum (4-fold) from IPF patients. In the lungs CHIT1 is expressed in a distinct subpopulation of profibrotic, disease-specific macrophages, which are only present in patients with ILDs and CHIT1 is one of the defining markers of this fibrosis-associated gene cluster. To define CHIT1 role in fibrosis, we used the therapeutic protocol of the bleomycin-induced pulmonary fibrosis mouse model. We demonstrate that in the context of chitinase induction and the macrophage-specific expression of CHIT1, this model recapitulates lung fibrosis in ILDs. Genetic inactivation of Chit1 attenuated bleomycin-induced fibrosis (decreasing the Ashcroft scoring by 28%) and decreased expression of profibrotic factors in lung tissues. Pharmacological inhibition of chitinases by OATD-01 reduced fibrosis and soluble collagen concentration. OATD-01 exhibited anti-fibrotic activity comparable to pirfenidone resulting in the reduction of the Ashcroft score by 32% and 31%, respectively. These studies provide a preclinical proof-of-concept for the antifibrotic effects of OATD-01 and establish CHIT1 as a potential new therapeutic target for IPF.

Liver Fibrosis: Mechanistic Concepts and Therapeutic Perspectives.

Liver fibrosis due to viral or metabolic chronic liver diseases is a major challenge of global health. Correlating with liver disease progression, fibrosis is a key factor for liver disease outcome and risk of hepatocellular carcinoma (HCC). Despite different mechanism of primary liver injury and disease-specific cell responses, the progression of fibrotic liver disease follows shared patterns across the main liver disease etiologies. Scientific discoveries within the last decade have transformed the understanding of the mechanisms of liver fibrosis. Removal or elimination of the causative agent such as control or cure of viral infection has shown that liver fibrosis is reversible. However, reversal often occurs too slowly or too infrequent to avoid life-threatening complications particularly in advanced fibrosis. Thus, there is a huge unmet medical need for anti-fibrotic therapies to prevent liver disease progression and HCC development. However, while many anti-fibrotic candidate agents have shown robust effects in experimental animal models, their anti-fibrotic effects in clinical trials have been limited or absent. Thus, no approved therapy exists for liver fibrosis. In this review we summarize cellular drivers and molecular mechanisms of fibrogenesis in chronic liver diseases and discuss their impact for the development of urgently needed anti-fibrotic therapies.

Targeting the Wnt signaling pathway: the challenge of reducing scarring without affecting repair.

Introduction: Globally, deaths from liver disease are increasing and for most patients there are few curative options. Fibrosis or scarring is often associated with the formation and progression of liver disease; however, clinical anti-fibrotic therapies are lacking. Recent work has shown that Wnt signaling, a signaling pathway that is necessary for embryonic development and cancer, can also regulate scar formation in the liver.Areas covered: This article seeks to shed light on the dualistic role of Wnt signaling in liver regeneration following injury and how Wnt signaling can regulate scar formation. It also discusses how Wnt signaling cooperates with other classical fibrogenic signaling cascades, such as TGFß signaling. Finally, the article examines recent advances in the development of Wnt signaling pathway inhibitors and asks whether repurposing these agents as anti-fibrotic therapies is a realistic option.Expert opinion: The understanding of Wnt signaling in liver regeneration and fibrosis is in its infancy and whilst new generations of Wnt pathway inhibitors have shown anti-fibrotic effects, further research is necessary to enhance our understanding of the Wnt-landscape in different patterns of liver disease. This will accelerate the development of more specific Wnt inhibitor-based anti-fibrotics.

Current and Future Techniques in Wound Healing Modulation after Glaucoma Filtering Surgeries.

Filtering surgeries are frequently used for controlling intraocular pressure in glaucoma patients. The long-term success of operation is intimately influenced by the process of wound healing at the site of surgery. Indeed, if has not been anticipated and managed accordingly, filtering surgery in high-risk patients could end up in bleb failure. Several strategies have been developed so far to overcome excessive scarring after filtering surgery. The principal step involves meticulous tissue handling and modification of surgical technique, which can minimize the severity of wound healing response at the first place. However, this is usually insufficient, especially in those with high-risk criteria. Thus, several adjuvants have been tried to stifle the exuberant scarring after filtration surgery. Conventionally, corticosteroids and anti-fibrotic agents (including 5-fluorouracil and Mitomycin-C) have been used for over three decades with semi-acceptable outcomes. Blebs and bleb associated complications are catastrophic side effects of anti-fibrotic agents, which occasionally are encountered in a subset of patients. Therefore, research continues to find a safer, yet effective adjuvant for filtering surgery. Recent efforts have primarily focused on selective inhibition of growth factors that promote scarring during wound healing process. Currently, only anti-VEGF agents have gained widespread acceptance to be translated into routine clinical practice. Robust evidence for other agents is still lacking and future confirmative studies are warranted. In this review, we explain the importance of wound healing process during filtering surgery, and describe the conventional as well as potential future adjuvants for filtration surgeries.

Diabetic nephropathy: What does the future hold?

The consensus management of diabetic nephropathy (DN) in 2015 involves good control of glycaemia, dyslipidaemia and blood pressure (BP). Blockade of the renin-angiotensin-aldosterone system using angiotensin-converting enzyme inhibitors, angiotensin-2 receptor blockers or mineralocorticoid inhibitors are key therapeutic approaches, shown to be beneficial once overt nephropathy is manifest, as either, or both, of albuminuria and loss of glomerular filtration rate. Some significant additional clinical benefits in slowing the progression of DN was reported from the Remission clinic experience, where simultaneous intensive control of BP, tight glycaemic control, weight loss, exercise and smoking cessation were prioritised in the management of DN. This has not proved possible to translate to more conventional clinical settings. This review briefly looks over the history and limitations of current therapy from landmark papers and expert reviews, and following an extensive PubMed search identifies the most promising clinical biomarkers (both established and proposed). Many challenges need to be addressed urgently as in order to obtain novel therapies in the clinic; we also need to examine what we mean by remission, stability and progression of DN in the modern era.