Antifibrotic Therapy Research Articles

Modulating the HSP90 control over NFκB/NLRP3/Caspase-1 axis is a new therapeutic target in the management of liver fibrosis: Insights into the role of TAS-116 (Pimitespib)

Aberrant activation of the NLRP3 inflammasome is recognized to induce a chronic inflammatory response in the liver, ultimately leading to hepatic fibrosis. HSP90 is suggested to regulate NLRP3 activation and its downstream signaling. This study is the first to explore the potential therapeutic role of pimitespib in mitigating liver fibrosis in rats. The results of the study revealed that pimitespib effectively suppressed hepatic inflammation and fibrogenesis by modulating HSP90's control over the NFκB/NLRP3/caspase-1 axis. In vitro experiments demonstrated that pimitespib reduced LDH levels and increased hepatocyte survival, whereas in vivo, it prolonged the survival of rats with hepatic fibrosis. Additionally, pimitespib exhibited improvements in the function and microscopic characteristics of rat livers. Pimitespib effectively inhibited NFκB, which serves as the priming signal for NLRP3 activation. Pimitespib's inhibitory effect on NLRP3, identified as an HSP90 client protein, plays a central role in the observed anti-fibrotic effect. The simultaneous inhibition of both priming and activation signals of NLRP3 by pimitespib led to a reduction in caspase-1 activity and subsequent suppression of the N-terminal fragment of gasdermin D, ultimately constraining hepatocyte pyroptotic cell death. These diverse effects were associated with a decrease in the transcription of inflammatory mediators IL-1β, IL-18, and TNF-α, as well as the fibrogenic mediators TGF-β, TIMP-1, PDGF-BB, and Col1a1. Moreover, pimitespib induced the expression of HSP70, which could further contribute to the repression of fibrosis development. In summary, our findings provide an evolutionary perspective on managing liver fibrosis, positioning pimitespib as a promising candidate for anti-inflammatory and antifibrotic therapy.

Spatial transcriptomic characterization of pathologic niches in IPF.

Despite advancements in antifibrotic therapy, idiopathic pulmonary fibrosis (IPF) remains a medical condition with unmet needs. Single-cell RNA sequencing (scRNA-seq) has enhanced our understanding of IPF but lacks the cellular tissue context and gene expression localization that spatial transcriptomics provides. To bridge this gap, we profiled IPF and control patient lung tissue using spatial transcriptomics, integrating the data with an IPF scRNA-seq atlas. We identified three disease-associated niches with unique cellular compositions and localizations. These include a fibrotic niche, consisting of myofibroblasts and aberrant basaloid cells, located around airways and adjacent to an airway macrophage niche in the lumen, containing SPP1+ macrophages. In addition, we identified an immune niche, characterized by distinct lymphoid cell foci in fibrotic tissue, surrounded by remodeled endothelial vessels. This spatial characterization of IPF niches will facilitate the identification of drug targets that disrupt disease-driving niches and aid in the development of disease relevant in vitro models.

Elucidation of the anti-fibrotic diseases mechanism of chelerythrine by integrative approach of network pharmacology and experimental verification

In the present study, we conducted an integrative approach of network pharmacology and experimental validation study to elucidate the underlying mechanisms of Chelerythrine (CLT), in treating fibrotic diseases (FD), which are disorders characterised by excessive accumulation of extracellular matrix. 27 common targets of CLT against FD were analysed, and these common targets were used to construct the PPI network. The results of GO and KEGG enrichment analyses suggested that CLT exerted pharmacological effects on FD by regulating mTOR signalling pathway, AKT-PI3K pathway and apoptosis signalling pathway. Finally, molecular docking confirmed a strong binding affinity between CLT and the core target proteins. CLT has inhibitory effects on the proliferation and migration of L929 cells, CLT could promote cell apoptosis. CLT decreased levels of the Bcl-2, p-AKT/AKT, p-mTOR/mTOR and p-PI3K/PI3K, meanwhile increased levels of the Bax. Taken together, these results indicate that CLT may be a potential drug for anti-fibrotic diseases therapy.

Abstract We108: Adipocyte Enhancer Binding Protein 1 (AEBP1) Inhibition as a Potential Anti-Fibrotic Therapy in Heart Failure

Introduction: Cardiac fibrosis is one of the major hallmarks of heart failure (HF) progression. Fibrosis is initiated as a repair mechanism following any kind of cardiac injury including a heart attack, inflammation, hypertension, etc. Briefly, fibroblasts are activated to form myofibroblasts that secrete collagen. Persistent fibroblast activation leads to excess collagen deposition leading to tissue stiffening and impaired contractility and thereby HF. To date, there is no anti-fibrotic therapy used in HF patients. Using bulk and snRNA sequencing data performed on myocardial tissue from HF patients, we identified adipocyte enhancer binding protein (AEBP1) to be significantly upregulated in activated fibroblasts. AEBP1 has been shown to play a crucial role in fibroblast activation following injury in the kidney, liver, and lungs. AEBP1 inhibition resulted in fibrosis attenuation in these organs. However, its role in cardiac fibrosis is not well understood. Hypothesis: We hypothesize that AEBP1 is crucial for cardiac fibroblast activation and AEBP1 inhibition will prevent collagen secretion and lead to improved cardiac function. Methods: Human cardiac fibroblasts (HCF) from non-failing donors were used for in vitro experiments. AdV-CMV-AEBP1 was used for AEBP1 overexpression (OE) and AdV-CMV-shAEBP1 was used to knockdown (KD) AEBP1 in vitro. AAV9-CMV-shAEBP1 was used for in vivo KD of AEBP1 in mice following myocardial infarction (MI). Human myocardial slices from n=6 HF patients were used and AdV-CMV-shAEBP1 was used to knockdown AEBP1 in human samples. Results and Discussion: AEBP1 OE in HCF resulted in fibroblast activation and collagen secretion (n=6, p=0.002). Contrarily, loss of AEBP1 significantly prevented fibroblast activation, evident from a reduction in transgelin (SM22) (n=6, p=0.02) and collagen (COL1A1) protein levels (n=6, p=0.01). AEBP1 KD in a mouse model of acute cardiac fibrosis resulted in reduced fibrosis and improved cardiac function (n=6, 12% absolute improvement compared to untreated mice, relative improvement in ejection fraction, p=0.02). Tissue culture studies of human HF myocardium showed a significant improvement in cardiac structure evident from reduced cardiomyocyte hypertrophy (n=6 HF patients, p=0.05) and reduced fibrosis (n=6, p<0.0001) following AEBP1 KD. Overall, we show that AEBP1 plays a critical role in fibrogenesis, and its inhibition has the potential to attenuate fibrosis in acute and chronic HF.

Abstract Tu101: Measuring Fibrosis Progression in Duchenne Cardiomyopathy Using Cardiac Magnetic Resonance in mice

Introduction: Transthoracic echocardiogram (TTE) is currently the gold standard for measuring cardiac function in mouse models of cardiomyopathy, however, it has its limitations. Challenges include poor acoustic windows, lower reproducibility, larger margin of error, and inability to accurately detect fibrosis. The detection of fibrosis is critical for assessing the severity of cardiac involvement and monitoring disease progression in Duchenne muscular dystrophy (DMD). Cardiac magnetic resonance imaging (CMR) can be used to more accurately measure cardiac function, chamber volumes, and tissue characterization to monitor the progression of fibrosis, including with parametric T1 mapping and late gadolinium enhancement (LGE). In this study, we have used a dystrophic mouse model (D2. mdx ) on the DBA/2J genetic background as a preclinical model of DMD. Hypothesis: We hypothesize that CMR can detect worsening cardiac function and signs of fibrosis in the left ventricle of D2. mdx mice compared to wildtype (DBA) controls. Methods: In a study group of 12 age-matched male mice (8 mdx, 4 DBA), CMR was performed with contrast to determine cardiac function and fibrotic developments in the heart. Results: D2. mdx mice displayed a higher left ventricular end-diastolic volume compared to DBA mice (32.8 ± 3.6 µL vs 27.4 ± 1.5 µL, p < 0.05). Global longitudinal strain was decreased in D2. mdx compared to DBA mice (-11.0 ± 3.5% vs -18.2 ± 2.2%, p < 0.05). Native T1 mapping (Fig 1A) showed significantly higher mean T1 times in D2. mdx mice compared to DBA controls (Fig 1B). LGE in the myocardium of the left ventricle was noted in 6 of 8 of the D2. mdx mice (Fig 1C), but not in DBA mice. Logistic regression modeling showed strong predictive value detecting LGE with increasing native T1 times (Fig 1D). Conclusion: CMR can detect tissue changes in D2. mdx myocardium representing fibrotic changes. Native T1 may be useful in longitudinal studies of antifibrotic therapies in these models.

Targeting the liver clock improves fibrosis by restoring TGF-β signaling

Liver fibrosis is the major driver of hepatocellular carcinoma and liver disease-related death. Approved antifibrotic therapies are absent and compounds in development have limited efficacy. Increased TGF-β signaling drives collagen deposition by hepatic stellate cells (HSCs)/myofibroblasts. Here, we aimed to dissect the role of the circadian clock (CC) in controlling TGF-β signaling and liver fibrosis. Using CC-mutant mice, enriched HSCs and myofibroblasts obtained from healthy and fibrotic mice in different CC phases and loss-of-function studies in human hepatocytes and myofibroblasts, we investigated the relationship between CC and TGF-β signaling. We explored hepatocyte-myofibroblast communication through bioinformatic analyses of single-nuclei transcriptomes and performed validation in cell-based models. Using mouse models for MASH (metabolic dysfunction-associated steatohepatitis)-related fibrosis and spheroids from patients with liver disease, we performed proof-of-concept studies to validate pharmacological targetability and clinical translatability. We discovered that the CC oscillator temporally gates TGF-β signaling and this regulation is broken in fibrosis. We demonstrate that HSCs and myofibroblasts contain a functional CC with rhythmic expression of numerous genes, including fibrogenic genes. Perturbation studies in hepatocytes and myofibroblasts revealed a reciprocal relationship between TGF-β activation and CC perturbation, which was confirmed in patient-derived exvivo and invivo models. Pharmacological modulation of CC-TGF-β signaling inhibited fibrosis in mouse models invivo as well as in patient-derived liver spheroids. The CC regulates TGF-β signaling, and the breakdown of this control is associated with liver fibrosis in patients. Pharmacological proof-of-concept studies across different models have uncovered the CC as a novel therapeutic target for liver fibrosis - a growing unmet medical need. Liver fibrosis due to metabolic diseases is a global health challenge. Many liver functions are rhythmic throughout the day, being controlled by the circadian clock (CC). Here we demonstrate that regulation of the CC is perturbed upon chronic liver injury and this perturbation contributes to fibrotic disease. By showing that a compound targeting the CC improves liver fibrosis in patient-derived models, this study provides a novel therapeutic candidate strategy to treat fibrosis in patients. Additional studies will be needed for clinical translation. Since the findings uncover a previously undiscovered profibrotic mechanism and therapeutic target, the study is of interest for scientists investigating liver disease, clinical hepatologists and drug developers.

Endothelial RUNX3 controls LSEC dysfunction and angiocrine LRG1 signaling to prevent liver fibrosis.

Liver fibrosis represents a global health burden, given the paucity of approved antifibrotic therapies. Liver sinusoidal endothelial cells (LSECs) play a major gatekeeping role in hepatic homeostasis and liver disease pathophysiology. In early tumorigenesis, runt-related transcription factor 3 (RUNX3) functions as a sentinel; however, its function in liver fibrosis in LSECs remains unclear. This study aimed to investigate the role of RUNX3 as an important regulator of the gatekeeping functions of LSECs and explore novel angiocrine regulators of liver fibrosis. Mice with endothelial Runx3 deficiency develop gradual and spontaneous liver fibrosis secondary to LSEC dysfunction, thereby more prone to liver injury. Mechanistic studies in human immortalized LSECs and mouse primary LSECs revealed that IL-6/JAK/STAT-3 pathway activation was associated with LSEC dysfunction in the absence of RUNX3. Single-cell RNA sequencing and quantitative RT-PCR revealed that leucine-rich alpha-2-glycoprotein 1 (LRG1) was highly expressed in RUNX3-deficient and dysfunctional LSECs. In in vitro and coculture experiments, RUNX3-depleted LSECs secreted LRG1, which activated hepatic stellate cells via TGFBR1-SMAD2/3 signaling in a paracrine manner. Furthermore, circulating LRG1 levels were elevated in mouse models of liver fibrosis and in patients with fatty liver and cirrhosis. RUNX3 deficiency in the endothelium induces LSEC dysfunction, LRG1 secretion, and liver fibrosis progression. Therefore, endothelial RUNX3 is a crucial gatekeeping factor in LSECs, and profibrotic angiocrine LRG1 may be a novel target for combating liver fibrosis.

Liver Fibrosis: From Basic Science towards Clinical Progress, Focusing on the Central Role of Hepatic Stellate Cells.

The burden of chronic liver disease is globally increasing at an alarming rate. Chronic liver injury leads to liver inflammation and fibrosis (LF) as critical determinants of long-term outcomes such as cirrhosis, liver cancer, and mortality. LF is a wound-healing process characterized by excessive deposition of extracellular matrix (ECM) proteins due to the activation of hepatic stellate cells (HSCs). In the healthy liver, quiescent HSCs metabolize and store retinoids. Upon fibrogenic activation, quiescent HSCs transdifferentiate into myofibroblasts; lose their vitamin A; upregulate α-smooth muscle actin; and produce proinflammatory soluble mediators, collagens, and inhibitors of ECM degradation. Activated HSCs are the main effector cells during hepatic fibrogenesis. In addition, the accumulation and activation of profibrogenic macrophages in response to hepatocyte death play a critical role in the initiation of HSC activation and survival. The main source of myofibroblasts is resident HSCs. Activated HSCs migrate to the site of active fibrogenesis to initiate the formation of a fibrous scar. Single-cell technologies revealed that quiescent HSCs are highly homogenous, while activated HSCs/myofibroblasts are much more heterogeneous. The complex process of inflammation results from the response of various hepatic cells to hepatocellular death and inflammatory signals related to intrahepatic injury pathways or extrahepatic mediators. Inflammatory processes modulate fibrogenesis by activating HSCs and, in turn, drive immune mechanisms via cytokines and chemokines. Increasing evidence also suggests that cellular stress responses contribute to fibrogenesis. Recent data demonstrated that LF can revert even at advanced stages of cirrhosis if the underlying cause is eliminated, which inhibits the inflammatory and profibrogenic cells. However, despite numerous clinical studies on plausible drug candidates, an approved antifibrotic therapy still remains elusive. This state-of-the-art review presents cellular and molecular mechanisms involved in hepatic fibrogenesis and its resolution, as well as comprehensively discusses the drivers linking liver injury to chronic liver inflammation and LF.

Radioproteomics stratifies molecular response to antifibrotic treatment in pulmonary fibrosis.

Antifibrotic therapy with nintedanib is the clinical mainstay in the treatment of progressive fibrosing interstitial lung disease (ILD). High-dimensional medical image analysis, known as radiomics, provides quantitative insights into organ-scale pathophysiology, generating digital disease fingerprints. Here, we performed an integrative analysis of radiomic and proteomic profiles (radioproteomics) to assess whether changes in radiomic signatures can stratify the degree of antifibrotic response to nintedanib in (experimental) fibrosing ILD. Unsupervised clustering of delta radiomic profiles revealed 2 distinct imaging phenotypes in mice treated with nintedanib, contrary to conventional densitometry readouts, which showed a more uniform response. Integrative analysis of delta radiomics and proteomics demonstrated that these phenotypes reflected different treatment response states, as further evidenced on transcriptional and cellular levels. Importantly, radioproteomics signatures paralleled disease- and drug-related biological pathway activity with high specificity, including extracellular matrix (ECM) remodeling, cell cycle activity, wound healing, and metabolic activity. Evaluation of the preclinical molecular response-defining features, particularly those linked to ECM remodeling, in a cohort of nintedanib-treated fibrosing patients with ILD, accurately stratified patients based on their extent of lung function decline. In conclusion, delta radiomics has great potential to serve as a noninvasive and readily accessible surrogate of molecular response phenotypes in fibrosing ILD. This could pave the way for personalized treatment strategies and improved patient outcomes.

Research Progress of Idiopathic Pulmonary Fibrosis Complicated with Lung Cancer

Context: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrotic interstitial disease with unknown cause and pathogenesis. Idiopathic pulmonary fibrosis patients are more likely to be concomitant with lung cancer (LC) than normal older smoking men. Currently, there is no unified expert consensus on the diagnosis and treatment of IPF combined with lung cancer (IPF-LC) patients. Evidence Acquisition: We performed a computerized search of PubMed database with keywords: idiopathic pulmonary fibrosis complicated with LC and therapy. Results: Idiopathic pulmonary fibrosis is an independent risk factor for LC, and there are similar genetic mutations, epigenetic changes, and signaling pathways between IPF and LC. acute exacerbation of IPF (AE-IPF) poses a significant challenge in the treatment of IPF-LC patients, as surgery, chemotherapy, and targeted therapy may all trigger AE-IPF leading to patient death. The clinical benefits of anti-fibrotic therapy drugs such as nintedanib or combined therapy targeting lung fibrosis and LC are expected to outweigh adverse reactions. Conclusions: Combination therapy may be an effective strategy for treating IPF-LC in the future, and there is an urgent need to develop appropriate preclinical animal models and conduct more clinical studies to find safe and effective new strategies for treating IPF-LC.

Metabolic dysfunction-associated liver disease and diabetes: Matrix remodeling, fibrosis, and therapeutic implications.

Metabolic dysfunction-associated liver disease (MASLD) and steatohepatitis (MASH) are becoming the most common causes of chronic liver disease in the United States and worldwide due to the obesity and diabetes epidemics. It is estimated that by 2030 close to 100 million people might be affected and patients with type 2 diabetes are especially at high risk. Twenty to 30% of patients with MASLD can progress to MASH, which is characterized by steatosis, necroinflammation, hepatocyte ballooning, and in advanced cases, fibrosis progressing to cirrhosis. Clinically, it is recognized that disease progression in diabetic patients is accelerated and the role of various genetic and epigenetic factors, as well as cell-matrix interactions in fibrosis and stromal remodeling, have recently been recognized. While there has been great progress in drug development and clinical trials for MASLD/MASH, the complexity of these pathways highlights the need to improve diagnosis/early detection and develop more successful antifibrotic therapies that not only prevent but reverse fibrosis.

The Early On-treatment Stiffness Decline Attributed to the Improved Hepatic Inflammation in Fibrotic Chronic Hepatitis B.

Hepatic inflammation, the driver of fibrosis progression in liver disease, can impact the accuracy of liver stiffness measurement (LSM). We wondered whether the decline in LSM value during the early antiviral phase was mainly attributed to the control of hepatic inflammation or the regression of fibrosis in patients with fibrotic/cirrhotic chronic hepatitis B (CHB). The study cohort was composed of 82 patients with CHB who underwent antiviral and antifibrotic therapy at the Fifth Medical Center of PLA General Hospital. All patients had liver biopsies at both baseline and 72 weeks posttherapy. Liver pathology and clinical data, including the LSM value, were collected. After 72 weeks of treatment, both the histologic activity index score and fibrosis score, as well as the LSM value, were significantly decreased (P < 0.001), compared with their baseline values. The pretreatment correlation of LSM value with either histologic activity index score (r = 0.526 vs r = 0.286) or fibrosis score (r = 0.677 vs r = 0.587) was attenuated at 72 weeks. Notably, logistic regression analysis revealed that the improvement in inflammation (odds ratio = 1.018, 95% CI: 1.002-1.031, P = 0.023) but not fibrosis (odds ratio = 0.994, 95% CI: 0.980-1.009, P = 0.414), had an impact on the change in LSM values between baseline and at 72-week treatment. The findings of this study suggest that in patients with fibrotic CHB receiving antiviral medication, the early phase reduction in LSM value was related to improved hepatic inflammation rather than fibrosis regression.

An antibody that inhibits TGF-β1 release from latent extracellular matrix complexes attenuates the progression of renal fibrosis.

Inhibitors of the transforming growth factor-β (TGF-β) pathway are potentially promising antifibrotic therapies, but nonselective simultaneous inhibition of all three TGF-β homologs has safety liabilities. TGF-β1 is noncovalently bound to a latency-associated peptide that is, in turn, covalently bound to different presenting molecules within large latent complexes. The latent TGF-β-binding proteins (LTBPs) present TGF-β1 in the extracellular matrix, and TGF-β1 is presented on immune cells by two transmembrane proteins, glycoprotein A repetitions predominant (GARP) and leucine-rich repeat protein 33 (LRRC33). Here, we describe LTBP-49247, an antibody that selectively bound to and inhibited the activation of TGF-β1 presented by LTBPs but did not bind to TGF-β1 presented by GARP or LRRC33. Structural studies demonstrated that LTBP-49247 recognized an epitope on LTBP-presented TGF-β1 that is not accessible on GARP- or LRRC33-presented TGF-β1, explaining the antibody's selectivity for LTBP-complexed TGF-β1. In two rodent models of kidney fibrosis of different etiologies, LTBP-49247 attenuated fibrotic progression, indicating the central role of LTBP-presented TGF-β1 in renal fibrosis. In mice, LTBP-49247 did not have the toxic effects associated with less selective TGF-β inhibitors. These results establish the feasibility of selectively targeting LTBP-bound TGF-β1 as an approach for treating fibrosis.

Analysis of culture and RNA isolation methods for precision-cut liver slices from cirrhotic rats

Precision-cut liver slices (PCLS) are increasingly used as a model to investigate anti-fibrotic therapies. However, many studies use PCLS from healthy animals treated with pro-fibrotic stimuli in culture, which reflects only the early stages of fibrosis. The effects of different culture conditions on PCLS from cirrhotic animals has not been well characterized and there is no consensus on optimal methods. In this study, we report a method for the collection and culture of cirrhotic PCLS and compare the effect of common culture conditions on viability, function, and gene expression. Additionally, we compared three methods of RNA isolation and identified a protocol with high yield and purity. We observed significantly increased albumin production when cultured with insulin-transferrin-selenium and dexamethasone, and when incubated on a rocking platform. Culturing with insulin-transferrin-selenium and dexamethasone maintained gene expression closer to the levels in fresh slices. However, despite stable viability and function up to 4 days, we found significant changes in expression of key genes by day 2. Interestingly, we also observed that cirrhotic PCLS maintain viability in culture longer than slices from healthy animals. Due to the influence of matrix stiffness on fibrosis and hepatocellular function, it is important to evaluate prospective anti-fibrotic therapies in a platform that preserves tissue biomechanics. PCLS from cirrhotic animals represent a promising tool for the development of treatments for chronic liver disease.

Molecular Endotypes of Idiopathic Pulmonary Fibrosis: A Latent Class Analysis of Two Multicenter Observational Cohorts.

Rationale: Idiopathic pulmonary fibrosis (IPF) causes irreversible fibrosis of the lung parenchyma. Although antifibrotic therapy can slow IPF progression, treatment response is variable. There exists a critical need to develop a precision medicine approach to IPF. Objectives: To identify and validate biologically driven molecular endotypes of IPF. Methods: Latent class analysis (LCA) was independently performed in prospectively recruited discovery (n = 875) and validation (n = 347) cohorts. Twenty-five plasma biomarkers associated with fibrogenesis served as class-defining variables. The association between molecular endotype and 4-year transplant-free survival was tested using multivariable Cox regression adjusted for baseline confounders. Endotype-dependent differential treatment response to future antifibrotic exposure was then assessed in a pooled cohort of patients naive to antifibrotic therapy at the time of biomarker measurement (n = 555). Measurements and Main Results: LCA independently identified two latent classes in both cohorts (P < 0.0001). WFDC2 (WAP four-disulfide core domain protein 2) was the most important determinant of class membership across cohorts. Membership in class 2 was characterized by higher biomarker concentrations and a higher risk of death or transplant (discovery, hazard ratio [HR], 2.02; 95% confidence interval [CI], 1.64-2.48; P < 0.001; validation, HR, 1.95; 95% CI, 1.34-2.82; P < 0.001). In pooled analysis, significant heterogeneity in treatment effect was observed between endotypes (P = 0.030 for interaction), with a favorable antifibrotic response in class 2 (HR, 0.64; 95% CI, 0.45-0.93; P = 0.018) but not in class 1 (HR, 1.19; 95% CI, 0.77-1.84; P = 0.422). Conclusions: In this multicohort study, we identified two novel molecular endotypes of IPF with divergent clinical outcomes and responses to antifibrotic therapy. Pending further validation, these endotypes could enable a precision medicine approach for future IPF clinical trials.

The impact of antifibrotic use on long-term clinical outcomes in the pulmonary fibrosis foundation registry

BackgroundIdiopathic pulmonary fibrosis (IPF) is a devastating interstitial lung disease (ILD) with a high mortality rate. The antifibrotic medications pirfenidone and nintedanib have been in use since 2014 for this disorder and are associated with improved rate of lung function decline. Less is known about their long-term outcomes outside of the clinical trial context.MethodsThe Pulmonary Fibrosis Foundation Patient Registry was used for this study. Patients with an IPF diagnosis made within a year of enrollment were included. The treated group was defined as patients receiving either pirfenidone or nintedanib for at least 180 days. The untreated group did not have any record of antifibrotic use. Demographic data, comorbidities, serial lung function, hospitalization, and vital status data were collected from the registry database. The primary outcomes were transplant-free survival, time to first respiratory hospitalization, and time to 10% absolute FVC decline. Time-to-event analyses were performed utilizing Cox proportional hazards models and the log-rank test. Model covariates included age, gender, smoking history, baseline lung function, comorbidities, and oxygen use.ResultsThe registry contained 1212 patients with IPF; ultimately 288 patients met inclusion criteria for the treated group, and 101 patients were designated as untreated. Patients treated with antifibrotics were significantly younger (69.8 vs. 72.6 years, p = 0.008) and less likely to have smoked (61.1% ever smokers vs. 72.3% never smokers, p = 0.04). No significant differences were seen in race, gender, comorbidities, or baseline pulmonary function between groups. The primary outcome of transplant-free survival was not significantly different between the two groups (adjusted HR 0.799, 95% CI 0.534–1.197, p = 0.28). Time to respiratory hospitalization was significantly shorter in the treated group (adjusted HR 2.12, 95% CI 1.05–4.30, p = 0.04). No significant difference in time to pulmonary function decline was seen between groups.ConclusionsThis multicenter study demonstrated 63% of newly diagnosed IPF patients had continuous antifibrotic usage. Antifibrotics were not associated with improved transplant-free survival or pulmonary function change but was associated with an increased hazard of respiratory hospitalization. Future studies should further investigate the role of antifibrotic therapy in clinically important outcomes in real-world patients with IPF and other progressive ILDs.

What has antifibrotic therapy changed for patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrotic interstitial lung disease of unknown cause. IPF is characterized by excessive production and deposition of extracellular matrix components, which lead to irreversible violations of the architectonics of lung tissue and loss of function. Without treatment, the average survival rate of patients after diagnosis does not exceed 3–5 years. However, published observations report improved survival over the past decade, due to the advent of antifibrotic drugs and earlier diagnosis. The benefits of antifibrotic therapy include a slower rate of reduction in forced lung capacity (FVC) and a reduction in mortality. Pirfenidone and nantedanib are the only currently approved antifibrotic drugs for the treatment of IPF. Several generic drugs with the INN pirfenidone are registered on the Russian market, including the drug PIRFASPEC® (267 mg capsules). Their efficacy and safety have been demonstrated both in randomized clinical trials and in real clinical practice studies. IPF patient registries, which have been maintained in many countries since 2010, provide additional information regarding the progression of the disease, the effectiveness of therapy, and the frequency of adverse events. Although they have a different mechanism of action and safety profile, their effectiveness in slowing the decline of FVC and reducing the risk of mortality over time is similar. However, IPF is still characterized by progressive shortness of breath and poor prognosis, as treatment can only delay the progression of IPF and cannot stop or reverse the damage. Although clinical trials of new drugs for the treatment of IPF are currently underway, no other drugs have yet been approved in the Russian Federation.

Association between anti-PL7 antibodies and increased fibrotic component in patients with antisynthetase syndrome and interstitial lung disease: a cross-sectional study.

To evaluate whether anti-PL7 and anti-PL12 autoantibodies are associated with a greater extent of the fibrotic component of ILD in ASSD patients. Patients with ILD-ASSD who were positive for one of the following autoantibodies: anti-Jo1, anti-PL7, anti-PL12, and anti-EJ were included. Clinical manifestations, CPK levels, pulmonary function tests, and HCRT assessments were prospectively collected according to the Goh index. The fibrotic, inflammatory, and overall extension of the Goh index and DLCO were assessed by multiple linear analyses and compared between ASSD antibody subgroups. Sixty-six patients were included; 17 were positive for anti-Jo1 (26%), 17 for anti-PL7 (26%), 20 for anti-PL12 (30%), and 9 (14%) for anti-EJ. Patients with anti-PL7 and anti-PL12 had a more extensive fibrotic component than anti-Jo1. Anti-PL7 patients had a 7.9% increase in the fibrotic extension (cβ = 7.9; 95% CI 1.863, 13.918), and the strength of the association was not modified after controlling for sex, age, and time of disease evolution (aβ = 7.9; 95% CI 0.677, 15.076) and also was associated with an increase in ILD severity after adjusting for the same variables, denoted by a lower DLCO (aβ = - 4.47; 95% CI - 8.919 to - 0.015). Anti-PL7-positive ASSD patients had more extensive fibrosis and severe ILD than the anti-Jo1 subgroup. This information is clinically useful and has significant implications for managing these patients, suggesting the need for early consideration of concurrent immunosuppressive and antifibrotic therapy.

Fibroblast Diversity and Epigenetic Regulation in Cardiac Fibrosis.

Cardiac fibrosis, a process characterized by excessive extracellular matrix (ECM) deposition, is a common pathological consequence of many cardiovascular diseases (CVDs) normally resulting in organ failure and death. Cardiac fibroblasts (CFs) play an essential role in deleterious cardiac remodeling and dysfunction. In response to injury, quiescent CFs become activated and adopt a collagen-secreting phenotype highly contributing to cardiac fibrosis. In recent years, studies have been focused on the exploration of molecular and cellular mechanisms implicated in the activation process of CFs, which allow the development of novel therapeutic approaches for the treatment of cardiac fibrosis. Transcriptomic analyses using single-cell RNA sequencing (RNA-seq) have helped to elucidate the high cellular diversity and complex intercellular communication networks that CFs establish in the mammalian heart. Furthermore, a significant body of work supports the critical role of epigenetic regulation on the expression of genes involved in the pathogenesis of cardiac fibrosis. The study of epigenetic mechanisms, including DNA methylation, histone modification, and chromatin remodeling, has provided more insights into CF activation and fibrotic processes. Targeting epigenetic regulators, especially DNA methyltransferases (DNMT), histone acetylases (HAT), or histone deacetylases (HDAC), has emerged as a promising approach for the development of novel anti-fibrotic therapies. This review focuses on recent transcriptomic advances regarding CF diversity and molecular and epigenetic mechanisms that modulate the activation process of CFs and their possible clinical applications for the treatment of cardiac fibrosis.

Challenges in the management of idiopathic pulmonary fibrosis from a low- and middle-income country

Idiopathic pulmonary fibrosis (IPF) is the most common progressive form of interstitial lung disease (ILD) that leads to gradual deterioration of lung function and ultimately death. Data from low- and middle-income countries (LMIC) on IPF is scarce. In this communication, we report the challenges encountered in managing IPF from Pakistan’s largest tertiary care centre. A total of 108 patients with IPF were evaluated at the Aga Khan University Hospital in Karachi, Pakistan from January 2017 to March 2020. A significant concern was that most patients with IPF presented late during their disease. A bigger challenge encountered in clinical practice was the cost and non-availability of antifibrotic therapy in the country until mid-2020. Successfully addressing these limitations, it is anticipated that better care will be available for the patients suffering from IPF in this part of the world. Keywords: Interstitial Lung Disease, Pulmonary Fibrosis; Idiopathic Pulmonary Fibrosis, LMIC.