Unlocking the potential of tranilast: Targeting fibrotic signaling pathways for therapeutic benefit.

Fibrosis is the excessive deposition of extracellular matrix in an organ or tissue that results from an impaired tissue repair in response to tissue injury or chronic inflammation. The progressive nature of fibrotic diseases and limited treatment options represent significant healthcare challenges. Despite the substantial progress in understanding the mechanisms of fibrosis, a gap persists translating this knowledge into effective therapeutics. Here, we discuss the critical mediators involved in fibrosis and the role of tranilast as a potential antifibrotic drug to treat fibrotic conditions. Tranilast, an antiallergy drug, is a derivative of tryptophan and has been studied for its role in various fibrotic diseases. These include scleroderma, keloid and hypertrophic scars, liver fibrosis, renal fibrosis, cardiac fibrosis, pulmonary fibrosis, and uterine fibroids. Tranilast exerts antifibrotic effects by suppressing fibrotic pathways, including TGF-ß, and MPAK. Because it disrupts fibrotic pathways and has demonstrated beneficial effects against keloid and hypertrophic scars, tranilast could be used to treat other conditions characterized by fibrosis.

Tranilast alleviates visceral hypersensitivity and colonic hyperpermeability by suppressing NLRP3 inflammasome activation in irritable bowel syndrome rat models.

Visceral hypersensitivity resulting from compromised gut barrier with activated immune system is a key feature of irritable bowel syndrome (IBS). Corticotropin-releasing factor (CRF) and Toll-like receptor 4 (TLR4) activate proinflammatory cytokine signaling to induce these changes, which is one of the mechanisms of IBS. As activation of the NLRP3 inflammasome by lipopolysaccharide (LPS) or TLR4 leads to release interleukin (IL)-1ß, the NLRP3 inflammasome may be involved in the pathophysiology of IBS. Tranilast, an anti-allergic drug has been demonstrated to inhibit the NLRP3 inflammasome, and we evaluated the impact of tranilast on visceral hypersensitivity and colonic hyperpermeability induced by LPS or CRF (IBS rat model). Visceral pain threshold caused by colonic balloon distention was measured by monitoring abdominal muscle contractions electrophysiologically. Colonic permeability was determined by quantifying the absorbed Evans blue within the colonic tissue. Colonic protein levels of NLRP3 and IL-1ß were assessed by immunoblot or ELISA. Intragastric administration of tranilast (20-200 mg/kg) for 3 days inhibited LPS (1 mg/kg)-induced visceral hypersensitivity and colonic hyperpermeability in a dose-dependent manner. Simultaneously, tranilast also abolished these alterations induced by CRF (50 µg/kg). LPS increased colonic protein levels of NLRP3 and IL-1ß, and tranilast inhibited these changes. ß-hydroxy butyrate, an NLRP3 inhibitor, also abolished visceral hypersensitivity and colonic hyperpermeability caused by LPS. In contrast, IL-1ß induced similar GI alterations to LPS, which were not modified by tranilast. In conclusion, tranilast improved visceral pain and colonic barrier by suppression of the NLRP3 inflammasome in IBS rat models. Tranilast may be useful for IBS treating.

Tolfenamic Acid Derivatives: A New Class of Transcriptional Modulators with Potential Therapeutic Applications for Alzheimer's Disease and Related Disorders.

The field of Alzheimer's disease (AD) has witnessed recent breakthroughs in the development of disease-modifying biologics and diagnostic markers. While immunotherapeutic interventions have provided much-awaited solutions, nucleic acid-based tools represent other avenues of intervention; however, these approaches are costly and invasive, and they have serious side effects. Previously, we have shown in AD animal models that tolfenamic acid (TA) can lower the expression of AD-related genes and their products and subsequently reduce pathological burden and improve cognition. Using TA as a scaffold and the zinc finger domain of SP1 as a pharmacophore, we developed safer and more potent brain-penetrating analogs that interfere with sequence-specific DNA binding at transcription start sites and predominantly modulate the expression of SP1 target genes. More importantly, the proteome of treated cells displayed ~75% of the downregulated products as SP1 targets. Specific levels of SP1-driven genes and AD biomarkers such as amyloid precursor protein (APP) and Tau proteins were also decreased as part of this targeted systemic response. These small molecules, therefore, offer a viable alternative to achieving desired therapeutic outcomes by interfering with both amyloid and Tau pathways with limited off-target systemic changes.

Therapeutic Effects of Long-Term Administration of Tranilast in an Animal Model for the Treatment of Fibroids.

Tranilast (N-3, 4-dimethoxycinnamoyl anthranilic acid) is an orally administered drug with antiallergic properties and approved in Japan and the Republic of Korea for the treatment of asthma and hypertrophic scars. Previous in vitro studies indicated that tranilast reduced fibroid growth through its inhibitory effects on cell proliferation and induction of apoptosis. The objective of this study was to determine the efficacy of tranilast for treatment of human-derived fibroids in a mouse model. SCID mice (ovariectomized, supplemented with estrogen and progesterone) were implanted with fibroid explants and treated for two months with tranilast (50 m/kg/daily) or the vehicle. After sacrifice, xenografts were excised and analyzed. Tranilast was well tolerated without adverse side effects. There was a 37% reduction in tumor weight along with a significant decrease in staining for Ki67, CCND1, and E2F1; a significant increase in nuclear staining for cleaved caspase 3; and reduced staining for TGF-ß3 and Masson's trichrome in the tranilast treated mice. There was a significant inhibition of mRNA and protein expression of fibronectin, COL3A1, CCND1, E2F1, and TGF-ß3 in the xenografts from the tranilast-treated mice. These promising therapeutic effects of tranilast warrant additional animal studies and human clinical trials to evaluate its efficacy for treatment of fibroids.

Impact of the TRPV2 Inhibitor on Advanced Heart Failure in Patients with Muscular Dystrophy: Exploratory Study of Biomarkers Related to the Efficacy of Tranilast.

Cardiomyopathy is the leading cause of death in patients with muscular dystrophy (MD). Tranilast, a widely used anti-allergic drug, has displayed inhibitory activity against the transient receptor potential cation channel subfamily V member 2 and improved cardiac function in MD patients. To identify urinary biomarkers that assess improved cardiac function after tranilast administration, we performed a urinary metabolomic study focused on oxidative fatty acids. Accompanying the clinical trial of tranilast, urine specimens were collected over 24 weeks from MD patients with advanced heart failure. Urinary levels of tetranor-PGDM (tetranor-prostaglandin D metabolite), a metabolite of prostaglandin D2, significantly decreased 12 weeks after tranilast administration and were correlated with BNP. These results suggest that prostaglandin-mediated inflammation, which increases with the pathological progression of heart failure in MD patients, was attenuated. Urinary prostaglandin E3 (PGE3) levels significantly increased 4 weeks after tranilast administration. There were positive correlations between the urinary levels of PGE3 and 8-hydroxy-2'-deoxyguanosine, an oxidative stress marker. High PGE3 levels may have a protective effect against cardiomyopathy in MD patients with high oxidative stress. Although further validation studies are necessary, urinary tetranor-PGDM and PGE3 levels may help the current understanding of the extent of advanced heart failure in patients with MD after tranilast administration.

Polymeric micelles effectively reprogram the tumor microenvironment to potentiate nano-immunotherapy in mouse breast cancer models.

Nano-immunotherapy improves breast cancer outcomes but not all patients respond and none are cured. To improve efficacy, research focuses on drugs that reprogram cancer-associated fibroblasts (CAFs) to improve therapeutic delivery and immunostimulation. These drugs, however, have a narrow therapeutic window and cause adverse effects. Developing strategies that increase CAF-reprogramming while limiting adverse effects is urgent. Here, taking advantage of the CAF-reprogramming capabilities of tranilast, we developed tranilast-loaded micelles. Strikingly, a 100-fold reduced dose of tranilast-micelles induces superior reprogramming compared to free drug owing to enhanced intratumoral accumulation and cancer-associated fibroblast uptake. Combination of tranilast-micelles and epirubicin-micelles or Doxil with immunotherapy increases T-cell infiltration, resulting in cures and immunological memory in mice bearing immunotherapy-resistant breast cancer. Furthermore, shear wave elastography (SWE) is able to monitor reduced tumor stiffness caused by tranilast-micelles and predict response to nano-immunotherapy. Micellar encapsulation is a promising strategy for TME-reprogramming and SWE is a potential biomarker of response.

Nanomicelle-generating Microneedles Loaded With Tranilast for Treatment of Hypertrophic Scars in a Rabbit Model.

BACKGROUND/AIM: Hypertrophic scars (HS) are the result of pathological wound healing characterized by a red, raised scar formation. The goal of this research was development of a new method for treatment of HS formation. MATERIALS AND METHODS: A tranilast-loaded microneedle (TMN) was developed and applied in a rabbit ear model to treat an induced HS. Scar elevation index, the thickness of dorsal skin by hematoxylin and eosin staining, collagen deposition by Masson trichrome staining and expression of myofibroblast biomarker proteins were evaluated. RESULTS: The 12×12 array of the TMN containing 2.9 µg tranilast per needle released more than 80% of the drug within 30 min. During the procedure, control, non-loaded MN and TMN loaded with three different doses of tranilast (low: 2.5-3, medium: 25-30, and high: 100-150 µg) were applied to the HS in rabbit ears. High-level TMN led to a clear and natural appearance of skin, a decrease in scar elevation index by 47% and decline in the thickness of the epidermis from 69.27 to 15.92 µm when compared to the control group. Moreover, the collagen density also decreased in groups treated with medium- or high-level TMNs, by 10.2% and 9.06%, respectively. Furthermore, the expression of transforming growth factor-ß, collagen-1, and α-smooth muscle actin proteins was reduced in TMN-treated HSs compared to the control. CONCLUSION: The findings show the overall efficacy of TMNs in inhibiting HS. Thus, use of TMN is a simple and cosmetic remedy for HS, with good protection and reliability.

Deep Angiomyxoma of the Thigh That Is Difficult to Diagnose: A Case Report and Literature Review.

We present an extremely rare case of deep angiomyxoma (DAM) in the thigh that was misdiagnosed as desmoid-type fibromatosis. A 40-year-old Japanese woman presented with a mass on the left thigh. The histological diagnosis by needle biopsy was desmoid-type fibromatosis; the tumor grew slowly and was resected 4 years later. The histological diagnosis from the resected tumor was DAM. As of 16 months post-surgery, the patient has not noticed any local recurrence. Although DAM in a lower extremity is extremely rare, clinicians must be aware of its possible occurrence in areas relatively close to the pelvis.

Anti-cancer effects of Tranilast: An update.

Tranilast (TRN) or (N-3,4 -dimethoxy cinnamoyl]-anthranilic acid) is an analog of a tryptophan metabolite and is identified mainly as an anti-allergic agent with limited side effects. The anti-cancer effects of tranilast either alone or in combination with chemotherapeutic drugs have been evidenced in several pre-clinical studies. The main mechanism of action of tranilast includes targeting and modulation of various signaling and immune regulatory pathways including Transforming growth factor-beta (TGF-ß), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), phosphatidylinositol 3-kinase (PI3K), MAP-Kinase (MAPK), Protein kinase B ( Akt/PKB), c-Jun N-terminal kinase, modulation of cancer stem cells, etc. Most of these pathways are involved in tumor proliferation, invasion, and metastasis and it is postulated that tranilast, with its low toxicity profile and high anti-carcinogenic abilities, can serve as a potential anti-tumorigenic agent. The main aim of this review is to provide updated information on the anti-cancer effects of tranilast and its significance as a therapeutic agent.

Study Protocol for a Multicenter, Open-Label, Single-Arm Study of Tranilast for Cardiomyopathy of Muscular Dystrophy.

Duchenne (DMD) and other forms of muscular dystrophy (MD) are collectively rare and affect approx imately 20 per 100,000 people. The on-going development of exon skipping and other novel therapies for DMD is expected to lead to improvements in motor function prognosis. However, improvements in motor dysfunction with these novel therapies are associated with the risk of increase in cardiac burden. Development of therapies to improve cardiac function, therefore, is an urgent issue. This single-arm, open-label, multicenter study will include 20 patients with MD aged 13 years or older. Tranilast, a transient receptor potential cation channel subfamily V member 2 (TRPV2) inhibitor, will be administered orally for a period of 28 weeks at a dose of 300 mg/day divided into three daily doses. If consent to continue administration is obtained at 28 weeks, the drug will be administered for an additional 116 weeks. The primary outcome will be the change in brain natriuretic peptide (BNP) at 6 months after the start of administration compared to baseline. Tranilast is an anti-allergy agent that was developed in Japan. It has been used in a large number of clinical cases, including pediatric cases, and has been shown to be safe. We expect this study to provide basic data for developing new treatment method in cardiomyopathy/skeletal myopathy using TRPV2 inhibitors. Moreover, such therapies may also be effective in treating general heart failure without MD. Therefore, if the effectiveness of TRPV2 inhibitors could be confirmed in this study, great social and economic benefits could be achieved.

Role of transient receptor potential vanilloid subtype 2 in lower oesophageal sphincter in rat acid reflux oesophagitis.

Gastroesophageal reflux disease (GERD) is a common gastrointestinal disorder. In the present study, we investigated TRP vanilloid subfamily member 2 (TRPV2) expression in lower oesophageal sphincter (LES) and its involvement in acid reflux oesophagitis in rats. Expression of TRPV2 and nerve growth factor mRNAs was significantly enhanced in LES of rats with reflux oesophagitis compared with normal rats. TRPV2 was mainly expressed in inhibitory motor neurons, and partly in intrinsic and extrinsic primary afferent neurons, and macrophages in LES of normal and reflux oesophagitis rats. Number of TRPV2-immunopositive nerve fibres was significantly increased, but that of nNOS-, CGRP-, and PGP9.5-nerve fibres was not changed in reflux oesophagitis compared with normal group. Probenecid produced nitric oxide production and relaxation in LES and this response was significantly enhanced in oesophagitis compared with normal group. Probenecid-induced relaxant effect was blocked by a TRPV2 inhibitor, tranilast, and a NOS inhibitor, NG-nitro-l-arginine methyl ester, in reflux oesophagitis rats. Oral administration of tranilast significantly improved body weight loss, oesophageal lesions, and epithelial thickness in oesophagitis model. These results suggest that up-regulation of TRPV2 in inhibitory motor neurons is involved in LES relaxation in oesophagitis model. TRPV2 inhibition might be beneficial for treatment of GERD.

Tranilast: a potential anti-Inflammatory and NLRP3 inflammasome inhibitor drug for COVID-19.

SARS-CoV-2 is a type of beta-CoV that develops acute pneumonia, which is an inflammatory condition. A cytokine storm has been recognized as one of the leading causes of death in patients with COVID-19. ALI and ARDS along with multiple organ failure have also been presented as the consequences of acute inflammation and cytokine storm. It has been previously confirmed that SARS-CoV, as another member of the beta-CoV family, activates NLRP3 inflammasome and consequently develops acute inflammation in a variety of ways through having complex interactions with the host immune system using structural and nonstructural proteins. Numerous studies conducted on Tranilast have further demonstrated that the given drug can act as an effective anti-chemotactic factor on controlling inflammation, and thus, it can possibly help the improvement of the acute form of COVID-19 by inhibiting some key inflammation-associated transcription factors such as NF-κB and impeding NLRP3 inflammasome. Several studies have comparably revealed the direct effect of this drug on the prevention of inappropriate tissue's remodeling; inhibition of neutrophils, IL-5, and eosinophils; repression of inflammatory cell infiltration into inflammation site; restriction of factors involved in acute airway inflammation like IL-33; and suppression of cytokine IL-13, which increase mucosal secretions. Therefore, Tranilast may be considered as a potential treatment for patients with the acute form of COVID-19 along with other drugs.

The Discovery of Novel ACA Derivatives as Specific TRPM2 Inhibitors that Reduce Ischemic Injury Both In Vitro and In Vivo.

The transient receptor potential melastatin 2 (TRPM2) channel is associated with ischemia/reperfusion injury, inflammation, cancer, and neurodegenerative diseases. However, the limit of specific inhibitors impedes the development of TRPM2-targeted therapeutic agents. To discover more potent and selective TRPM2 inhibitors, 59 N-(p-amylcinnamoyl) anthranilic acid (ACA) derivatives were synthesized and evaluated using calcium imaging and electrophysiology approaches. Systematic structure-activity relationship studies resulted in some potent compounds inhibiting the TRPM2 channel with sub-micromolar half-maximal inhibitory concentration values. Among them, the preferred compound A23 exhibited TRPM2 selectivity over TRPM8 and TRPV1 channels as well as phospholipase A2 and showed neuroprotective activity in vitro. Following pharmacokinetic studies, A23 was further evaluated in a transient middle cerebral artery occlusion model in vivo, which significantly reduced cerebral infarction. These data indicate that A23 might serve as a useful tool for TRPM2-related research as well as a lead compound for the development of therapeutic agents for ischemic injury.

Clinical safety and efficacy of neoadjuvant combination chemotherapy of tranilast in advanced esophageal squamous cell carcinoma: Phase I/II study (TNAC).

BACKGROUND: Transient receptor potential vanilloid 2 (TRPV2) was previously shown to play an important role in the maintenance of cancer stem cells, and its specific inhibitor, tranilast, also has potential as a targeted therapeutic agent for esophageal squamous cell carcinoma (ESCC). The present study is being conducted to confirm the safety and efficacy of the additional use of tranilast with conventional preoperative adjuvant chemotherapy for patients with advanced ESCC. PATIENTS AND METHODS: Between 56 and 59 patients aged between 20 and 74 years with clinically diagnosed Stage II or Stage III ESCC will be enrolled. Eligible patients will receive preoperative adjuvant chemotherapy, 2 cycles of combination therapy with cisplatin, 5-fluorouracil, and tranilast. Recruitment started in November 2019, with the final follow-up being planned for March 2029. One subject has been enrolled since October 21, 2020. The pathological therapeutic effect is the primary endpoint. The objective response rate, safety of preoperative adjuvant chemotherapy, recurrence-free survival (RFS), and overall survival (OS) are the secondary endpoints. RFS and OS will be calculated as the time from surgery to first recurrence and all-cause death, respectively. ETHICS AND DISSEMINATION: This protocol has been approved by the Institutional Review Boards of Kyoto Prefectural University of Medicine and all participating hospitals in August 30, 2019 (Number: CRB5180001). Written informed consent will be obtained from all patients before their registration, which is in accordance with the Declaration of Helsinki. The results of the present study will be disseminated via publication in peer-reviewed journals. TRIAL REGISTRATION: Trial registration number jRCTs051190076.

SARS-CoV-2 infection: NLRP3 inflammasome as plausible target to prevent cardiopulmonary complications?

NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome has recently become an intriguing target of several chronic and viral diseases. Here, we argue that targeting NLRP3 inflammasome could be a strategy to prevent cardiovascular outcomes [fulminant myocarditis, heart failure, venous thromboembolism (VTE)] and acute respiratory distress syndrome (ARDS) in patients with SARS-CoV-2 infection. We discuss the rationale for NLRP3 targeting in clinical trials as an effective therapeutic strategy aimed to improve prognosis of COVID-19, analyzing the potential of two therapeutic options (tranilast and OLT1177) currently available in clinical practice.